Cellular pattern formations of some epithelia are believed to be governed by the direct lateral inhibition rule of cell differentiation. That is, initially equivalent cells are all competent to differentiate, but once a cell has differentiated, the cell inhibits its immediate neighbors from following this pathway. Such a differentiation repeats until all non-inhibited cells have differentiated. The cellular polygonal patterns can be characterized by the numbers of undifferentiated cells and differentiated ones. When the differentiated cells become large in (...) size, the polygonal pattern is deformed since more cells are needed to enclose the large cell. An actual example of such a cellular pattern was examined. The pupal wing epidermis of a butterfly Pieris rapae shows a transition of the equivalent-size cell pattern to the pattern involving large cells. The process of the transition was analyzed by using the method of weighted Voronoi tessellation that is useful for treatment of irregularly sized polygons. The analysis supported that the pattern transition of the early stage of the pupal wing epidermis is governed by the lateral inhibition rule. The differentiation takes place in order of largeness, but not smallness, of the apical polygonal area in the differentiating region of the pupal wing. (shrink)

In 1972, we proposed a theory of biological pattern formation in which concentration maxima of pattern forming substances are generated through local self- enhancement in conjunction with long range inhibition. Since then, much evidence in various developmental systems has confirmed the importance of autocatalytic feedback loops combined with inhibitory interaction. Examples are found in the formation of embryonal organizing regions, in segmentation, in the polarization of individual cells, and in gene activation. By computer simulations, we have shown that the (...) theory accounts for much of the regulatory phenomena observed, including signalling to regenerate removed parts. These self- regulatory features contribute to making development robust and error-tolerant. Furthermore, the resulting pattern is, to a large extent, independent of the details provided by initial conditions and inducing signals. (shrink)

One observes regulation at every biological level. Organisms, cells, and biochemical processes operate efficiently, normally wasting neither material nor energy, and adjusting their functions to external influences. Nature evidently has evolved mechanisms specifically dedicated to regulation at many levels. What is the molecular basis of this control?In the 1950s these molecular control mechanisms began to be explored seriously. The discoveries of feedback inhibition of enzyme activity were important because they gave an initial example of how regulation is achieved at (...) the molecular level. We showed that certain enzymes are composed of two parts, one for catalysis and another distinct part present only to regulate this catalysis. Catalytic activity can be either stimulated or inhibited when a small molecule in the environment combines with the enzyme's regulatory site. In particular, a final product of a metabolic pathway generates a feedback loop which automatically limits its own excessive production, by combining with the regulatory site of an early enzyme in that pathway. Later studies showed that catalytic and regulatory structures of some enzymes could be separated physically.The discovery of regulatory sites and their interaction with molecules unrelated to their substrates was the basis for the generalized allosteric concept. This concept extends the regulatory site idea to a wide variety of processes such as control of gene expression, hormone action, and cellular growth. (shrink)

From the beginning of time, humans believed they were the center of the universe. Such important beings could be nowhere else than at the very epicenter of existence, with all the other things revolving around them. Was this an arrogant position? Only time will tell. What is certain is that as some people were so certain of their significance, aeons later some other people became too confident in their unimportance. In such a context, the Earth quickly lost its privileged position (...) at the center of the universe and along with this, the ideas of absolute motion and time became unbearable for the modern intellect, which saw nothing but relativeness in everything. After years of accepting the ideas of relativity at face value without doubting them, scientists are now mature enough to start questioning everything as any true scientist would do, including their own basic assumptions. And one would be surprised to see that the basic assumptions of today’s science in physics (and cosmology alike) are based on philosophically dogmatic beliefs that humans are nothing more than insignificant specks of dust. These specks cannot be in any privileged position in the cosmos, nor can their frames of reference. These specks cannot be living on a planet that is not moving while everything else is. There can be no hint of our importance whatsoever. Hence, the Copernican principle that has poisoned scientific thinking for aeons now. When one analyzes the evidence provided by science to support the idea of relativity though, he would see that the same evidence can more easily and simply fit into a model where the Earth stands still. Yet, scientists preferred to revamp all physics by introducing the totally unintuitive ides of relativity – including the absolute limit of the speed of light – than even admitting the possibility of humans having any notion of central position in the cosmos. True scientists though should examine all possible explanations, including those that do not fit their beliefs. To the dismay of so many modern scientists who blindly believe the validity of the theory of relativity at face value, the movement towards a true and honest post-modern science where all assumptions are questioned, necessarily passes through a place where the Earth we live in stands still. Non-relativistic explanations of the Michelson Morley experiment, related to a motionless Earth or to ether, are viable alternatives that deserve their place in modern scientific thought. (shrink)

In the 1980s, physiologist Benjamin Libet conducted a series of ex-periments to test whether the will is free. Whilst he originally assumed that the will functions like an immaterial initiator of cerebral processes culminating in actions, he later began to think that it rather works like an immaterial veto inhib-iting unwanted actions by preventing unconsciously initiated cerebral processes from unfolding. Libet’s veto was widely criticized for its Cartesian dualist and interactionist implications. However, in 2016, Schultze-Kraft et al. adopted Libet’s idea (...) of an action-inhibiting veto and conducted a new experiment. Its goal was to test until which moment agents can inhibit an action that they already intended to do. Despite insisting on the material nature of the veto, the researchers also described the function of the veto in interactionist terms, namely as an act of the agent performed against her own cerebral processes. The purpose of this pa-per is to explain in which sense the veto in Libet’s and in Schultze-Kraft’s study is interactionist, and to provide a non-interactionist reinterpretation of the test subjects’ action inhibition in Schultze-Kraft’s experiment. (shrink)

The paper addresses the formation of striking patterns within originally near-homogenous tissue, the process prototypical for embryology, and represented in particularly purist form by cut sections of hydra regenerating, by internal reorganisation of the pre-existing tissue, a complete animal with head and foot. The essential requirements are autocatalytic, self-enhancing activation, combined with inhibitory or depletion effects of wider range – “lateral inhibition”. Not only de-novo-pattern formation, but also well known, striking features of developmental regulation such as induction, (...) class='Hi'>inhibition, and proportion regulation can be explained on this basis. The theory provides a mathematical recipe for the construction of molecular models with criteria for the necessary non-linear interactions. It has since been widely applied to different developmental processes. (shrink)

While many different mechanisms contribute to the generation of spatial order in biological development, the formation of morphogenetic fields which in turn direct cell responses giving rise to pattern and form are of major importance and essential for embryogenesis and regeneration. Most likely the fields represent concentration patterns of substances produced by molecular kinetics. Short range autocatalytic activation in conjunction with longer range “lateral” inhibition or depletion effects is capable of generating such patterns (Gierer and Meinhardt, 1972). Non-linear (...) reactions are required, and mathematical criteria were derived to design molecular models capable of pattern generation. The classical embryological feature of proportion regulation can be incorporated into the models. The conditions are mathematically necessary for the simplest two-factor case, and are likely to be a fair approximation in multi-component systems in which activation and inhibition are systems parameters subsuming the action of several agents. Gradients, symmetric and periodic patterns, in one or two dimensions, stable or pulsing in time, can be generated on this basis. Our basic concept of autocatalysis in conjunction with lateral inhibition accounts for self-regulatory biological features, including the reproducible formation of structures from near-uniform initial conditions as required by the logic of the generation cycle. Real tissue form, for instance that of budding Hydra, may often be traced back to local curvature arising within an initially relatively flat cell sheet, the position of evagination being determined by morphogenetic fields. Shell theory developed for architecture may also be applied to such biological processes. (shrink)

This essay is a history of an analogy. It charts a perceived relationship between the Trinity and the conjugal family in Anglo-French lay culture in the later Middle Ages. The association had long been known within theological discussions of the Trinity, antedating the works of St. Augustine, but his disapproving assessment was enduringly to inhibit its use. This essay shows the way that the analogy reemerged in the fourteenth century, bleeding through its theological bandages into debates about the ethics of (...) human relationships. Where this interrelationship has been considered before by medievalists, it has been in criticism of William Langland's Piers Plowman. This essay treats that poem, too, but also maintains that the synergy between marriage and the Trinity was not only the preoccupation of an eccentric poet but had a much more widespread cultural relevance. Indeed, I gather here a range of material, both literature and art, from across Europe between roughly the end of the thirteenth to the mid-fifteenth century; within that evidence, I identify a shared interest in reanimating the apparently exhausted topic of Trinitarianism and the family. (shrink)

This article elaborates on Putnam's ''discrete behavioral states'' model of dissociative identity disorder (Putnam, 1997) by proposing the involvement of the orbitalfrontal cortex in the development of DID and suggesting a potential neurodevelopmental mechanism responsible for the development of multiple representations of self. The proposed ''orbitalfrontal'' model integrates and elaborates on theory and research from four domains: the neurobiology of the orbitalfrontal cortex and its protective inhibitory role in the temporal organization of behavior, the development of emotion regulation, the development (...) of the self, and experience-dependent reorganizing neocortical processes. The hypothesis being proposed is that the experience-dependent maturation of the orbitalfrontal cortex in early abusive environments, characterized by discontinuity in dyadic socioaffective interactions between the infant and the caregiver, may be responsible for a pattern of lateral inhibition between conflicting subsets of self-representations which are normally integrated into a unified self. The basic idea is that the discontinuity in the early caretaking environment is manifested in the discontinuity in the organization of the developing child's self. (shrink)

A purely kinematic theory of movement runs the risk of having no explanatory power because it neglects the internal generative structures of the central nervous system. Distributed interaction between the agonist and antagonist systems would better simulate physiological mechanisms of oscillation, lateral inhibition, and synchronization, all of which have important roles in motor control.

The processing of information within the retino-tectal visual system of amphibians is decomposed into five major operational stages, three of them taking place in the retina and two in the optic tectum. The stages in the retina involve a spatially local high-pass filtering in connection to the perception of moving objects, separation of the receptor activity into ON- and OFF-channels regarding the distinction of objects on both light and dark backgrounds, spatial integration via near excitation and far-reaching inhibition. Variation (...) of the spatial range of excitation and inhibition allows to account for typical activities observed in a variety of classes of retina ganglion cells.Mathematical description of the operations in the tectum opticum include spatial summation of retinal output, and direct or indirect lateral inhibition between tectal cells. In the computer simulation, first the output of the mathematical retina model is computed which, then, is used as the input to the tectum model. The full spatio-temporal dynamics is taken into account.The simulations show that different combinations of strength of lateral inhibition on the one side and the response properties of the retina ganglion cells on the other side determine the response properties of tectal cell types involved in object recognition. (shrink)

The simultaneous possession of conflicting beliefs is both possible and logical within current models of human cognition. Specifically, evidence of lateral inhibition and state-dependent memory suggests a means by which conflicting beliefs can coexist without requiring “mental exotica.” We suggest that paradoxical self-deception enables the self-deceiver to store important information for use at a later time.

Proper wiring of the nervous system requires tight control of the number of nerve terminals that innervate a target tissue. Recent work by Deppmann et al.,1 now suggests that this is achieved by feedback‐mediated neuronal competition for target‐derived survival cues. The authors' model is inspired by the theory for pattern formation based on self‐activation and lateral inhibition, proposed by Meinhardt and Gierer more than 30 years ago.2 BioEssays 30:929–933, 2008. © 2008 Wiley Periodicals, Inc.

Children’s cognitive control and knowledge at school entry predict growth rates in analogical reasoning skill over time; however, the mechanisms by which these factors interact and impact learning are unclear. We propose that inhibitory control (IC) is critical for developing both the relational representations necessary to reason and the ability to use these representations in complex problem solving. We evaluate this hypothesis using computational simulations in a model of analogical thinking, Discovery of Relations by Analogy/Learning and Inference with Schemas and (...) Analogy (DORA/LISA; Doumas et al., 2008 ). Longitudinal data from children who solved geometric analogy problems repeatedly over 6 months show three distinct learning trajectories though all gained somewhat: analogical reasoners throughout, non-analogical reasoners throughout, and transitional – those who start non-analogical and grew to be analogical. Varying the base level of top-down lateral inhibition in DORA affected the model’s ability to learn relational representations, which, in conjunction with inhibition levels used in LISA during reasoning, simulated accuracy rates and error types seen in the three different learning trajectories. These simulations suggest that IC may not only impact reasoning ability but may also shape the ability to acquire relational knowledge given reasoning opportunities. (shrink)

The introductory personal remarks refer to my motivations for choosing research projects, and for moving from physics to molecular biology and then to development, with Hydra as a model system. Historically, Trembley’s discovery of Hydra regeneration in 1744 was the begin¬ning of developmental biology as we understand it, with passionate debates about preformation versus de novo generation, mechanisms versus organisms. In fact, seemingly conflicting bottom-up and top-down concepts are both required in combination to understand development. In modern terms, this means (...) analysing the molecules involved, as well as searching for physical principles underlying development within systems of molecules, cells and tissues. During the last decade, molecular biology has provided surprising and impressive evidence that the same types of mol¬ecules and molecular systems are involved in pattern formation in a wide range of organisms, including coelenterates like Hydra, and thus appear to have been “invented” early in evolution. Likewise, the features of certain systems, especially those of developmental regulation, are found in many different organisms. This includes the generation of spatial structures by the interplay of self-enhancing activation and “lateral” inhibitory effects of wider range, which is a main topic of my essay. Hydra regeneration is a particularly clear model for the formation of defined patterns within initially near-uniform tissues. In conclusion, this essay emphasizes the analysis of development in terms of physical laws, including the application of mathematics, and insists that Hydra was, and will continue to be, a rewarding model for understanding general features of embryogenesis and regeneration. -/- -/- . (shrink)

The processing of information within the retino-tectal visual system of amphibians is decomposed into five major operational stages, three of them taking place in the retina and two in the optic tectum. The stages in the retina involve (i) a spatially local high-pass filtering in connection to the perception of moving objects, (ii) separation of the receptor activity into ON- and OFF-channels regarding the distinction of objects on both light and dark backgrounds, (iii) spatial integration via near excitation and far-reaching (...) inhibition. Variation of the spatial range of excitation and inhibition allows to account for typical activities observed in a variety of classes of retina ganglion cells.Mathematical description of the operations in the tectum opticum include (i) spatial summation of retinal output (mainly of class-2 and class-3 retina ganglion cells), and (ii) direct or indirect lateral inhibition between tectal cells. In the computer simulation, first the output of the mathematical retina model is computed which, then, is used as the input to the tectum model. The full spatio-temporal dynamics is taken into account. (shrink)

In approaching the question of whether groups of people can have cognitive capacities that are fundamentally different than the cognitive capacities of the individuals within the group, we lay out a Multiple, Interactive Levels of Cognitive Systems (MILCS) framework. The goal of MILCS is to explain the kinds of cognitive processes typically studied by cognitive scientists, such as perception, attention, memory, categorization, decision making, problem solving, and judgment. Rather than focusing on high-level constructs such as modules in an information processing (...) flow diagram or internal representations, MILCS focuses on mechanisms that allow systems to engage in flexible, adaptive behavior. Examples of these mechanisms are network structure-process pairs that: combine data from perception with top-down theories, achieve consistency and consensus through information exchange, selectively attend to information globally assessed as relevant, and develop specialized units from originally homogeneous networks through competition among the units. Two such systems are considered in some detail -- lateral inhibition within a network for selecting from a candidate set the option that is most attractive, and a diffusion process for accumulating evidence to reach a generally rapid and accurate decision. These system descriptions are aptly applied at multiple levels, including within and across people. These systems provide accounts that unify cognitive processes across multiple levels, can be expressed in a common vocabulary provided by network science, are inductively powerful yet appropriately constrained, and are applicable to a large number of superficially diverse cognitive systems. Given that people are typically highly motivated to participate in strong groups, cognitively resourceful people will tend to form groups that effectively employ cognitive systems at higher levels than the individuals. The impressive cognitive capacities of individual people do not eliminate the need to talk about group cognition. Instead, smart people generally form smart groups. (shrink)

We reopen the investigation into the formal and conceptual relationship between bidirectional optimality theory (Blutner in J Semant 15(2):115–162, 1998 , J Semant 17(3):189–216, 2000 ) and game theory. Unlike a likeminded previous endeavor by Dekker and van Rooij (J Semant 17:217–242, 2000 ), we consider signaling games not strategic games, and seek to ground bidirectional optimization once in a model of rational step-by-step reasoning and once in a model of reinforcement learning. We give sufficient conditions for equivalence of bidirectional (...) optimality and the former, and show based on numerical simulations that bidirectional optimization may be thought of as a process of reinforcement learning with lateral inhibition. (shrink)

Determination of cell fate in the developing eye of Drosophila depends on a precise sequence of cellular interactions which generate the stereotypic array of ommatidia. In the eye imaginal disc, an initially unpatterned epithelial sheath of cells, the first step in this process may be the specification of R8 photoreceptor cells at regular intervals. Genes such as Notch and scabrous, known to be involved in bristle development, alos participate in this process, suggesting that the specification of ommatidial founder cells and (...) the formation of sensory organs in the adult epidermis may involve a similar mechanism, that of lateral inhibition. The subsequent steps of ommatidial assembly, following R8 assignment, involve a different mechanism: Undetermined cells read their position based on the contacts they make with neighbors that have already begun to differentiate. The development of the R7 photoreceptor cell, one of the eight photoreceptor cells in the ommatidium, is best understood. An important role seems to be played by sevenless, a receptor tyrosine kinase on the surface of the R7 precursor. It transmits the positional information– most likely encoded by the boss protein on the neighboring R8 cell membrane – into the cell via its tyrosine kinase, which activates a signal transduction cascade. Constitutive activation of the sevenless kinase by overexpression of an N‐terminally truncated form results in the diversion of other ommatidial cells into the R7 pathway suggesting that activation of the sevenless signalling pathway is sufficient to specify R7 development. Genetic dissection of this pathway should therefore identify components of a signalling cascade activated by a tyrosine kinase. (shrink)

BackgroundTinnitus is a common disease, and sound therapy is an effective method to alleviate it. Previous studies have shown that notched sound not only changes levels of cortical blood oxygen, but affects blood oxygen in specific cerebral cortical areas, such as Brodmann area 46, which is associated with emotion. Extensive evidence has confirmed that tinnitus is closely related to emotion. Whether notched sound plays a role in regulating the emotional center is still unclear.MethodsThis study included 29 patients with newly diagnosed (...) chronic tinnitus who were treated with notched sound. Functional near-infrared spectroscopy was conducted before and after treatment to observe bilateral changes in cortical blood oxygen in the cerebral hemispheres. We compared the changes in connectivity between the two regions of interest, as wells as other cortical regions before and after treatment.ResultsThe results showed That global connectivity between the bilateral auditory cortex of the superior temporal sulcus and the ipsilateral cortex did not change significantly between baseline and the completion of treatment, and That the connectivity between channel 14 and the right superior temporal sulcus decreased after treatment. The overall connectivity between the right BA46 region and the right cortex decreased after treatment, and decreases in connectivity after treatment were specifically found for channels 10 and 14 in the right parietal lobe and channels 16, 20, 21, and 22 in the frontal lobe, while there was no significant change on the left side. There were no significant changes in the questionnaire measures of tinnitus, anxiety, or depression before and after treatment.ConclusionThe results of the study indicate that cerebral cortex reorganization occurs in tinnitus patients after submitted to treatment with notched sound for 1 month, and that notched sound decreases the connectivity between the auditory cortex and specific brain regions.SignificanceNotched sound not only regulates the auditory center through lateral inhibition, but also alleviates tinnitus by reorganizing the emotional control center. (shrink)

While the benefits of both an external focus of attention (FOA) and of a longer quiet eye (QE) duration have been well researched in a wide range of sporting activities, little is known about the interaction of these two phenomena and how a potential interaction might influence performance. It was this study’s aim to investigate the interaction and potential effect on performance by using typical FOA instructions in a dart throwing task and examining both the QE and performance outcome. The (...) results replicate neither the benefit of an external FOA nor the benefit of a longer QE duration. However, an interaction was observed, as QE was prolonged by an earlier onset and later offset in the internal focus condition only. As the typical effect of a performance benefit due to an external focus could not be replicated, the interaction must be interpreted with caution. The results are discussed and interpreted in light of the inhibition hypothesis and possible avenues for future research are suggested. (shrink)

In numerous peripheral sense organs, external stimuli are detected by primary sensory neurons compartmentalized within specialized structures composed of cuticular or epithelial tissue. Beyond reflecting developmental constraints, such compartmentalization also provides opportunities for grouped neurons to functionally interact. Here, the authors review and illustrate the prevalence of these structural units, describe characteristics of compartmentalized neurons, and consider possible interactions between these cells. This article discusses instances of neuronal crosstalk, examples of which are observed in the vertebrate tastebuds and multiple types (...) of arthropod chemosensory hairs. Particular attention is paid to insect olfaction, which presents especially well‐characterized mechanisms of functional, cross‐neuronal interactions. These examples highlight the potential impact of peripheral processing, which likely contributes more to signal integration than previously considered. In surveying a wide variety of structural units, it is hoped that this article will stimulate future research that determines whether grouped neurons in other sensory systems can also communicate to impact information processing. (shrink)

Can qualia be analyzed by theories that contain only non-qualitative terms? A host of philosophers including Block, Levine, Nagel, and Jackson have argued that, in principle, they cannot. And yet psychophysicists have advanced explanations that seem to account for sensory appearances in terms of the operations of nervous systems. Here are some examples: Mach bands, the assimilation effect, and the Hermann grid illusion all have to do with the look of things, and all are routinely thought to be a consequence (...) of the structure of visual receptive fields. Simultaneous contrast and auditory tuning—both perceptual effects—are lateral inhibition phenomena. That television sets with only three phosphor colors can replicate natural scenes with thousands of distinguishable colors is due to our eyes having just three photopigments. The difference between a three-type receptoral configuration and an array of thousands of receptors with distinct responses accounts for the fact that hues form a closed loop in color space, whereas there are no closed pitch loops in auditory space. (shrink)

Neurosensory hearing loss is a growing problem of super‐aged societies. Cochlear implants can restore some hearing, but rebuilding a lost hearing organ would be superior. Research has discovered many cellular and molecular steps to develop a hearing organ but translating those insights into hearing organ restoration remains unclear. For example, we cannot make various hair cell types and arrange them into their specific patterns surrounded by the right type of supporting cells in the right numbers. Our overview of the topologically (...) highly organized and functionally diversified cellular mosaic of the mammalian hearing organ highlights what is known and unknown about its development. Following this analysis, we suggest critical steps to guide future attempts toward restoration of a functional organ of Corti. We argue that generating mutant mouse lines that mimic human pathology to fine‐tune attempts toward long‐term functional restoration are needed to go beyond the hope generated by restoring single hair cells in postnatal sensory epithelia. (shrink)

Spatial asymmetries are an intriguing feature of directed attention. Recent observations indicate an influence of temperament upon the direction of these asymmetries. It is unknown whether this influence generalises to visual orienting behaviour. The aim of the current study was therefore to explore the relationship between temperament and measures of spatial orienting as a function of target hemifield. An exogenous cueing task was administered to 92 healthy participants. Temperament was assessed using Carver and White's (1994) Behavioural Inhibition System and (...) Behavioural Activation System (BIS/BAS) scales. Individuals with high sensitivity to punishment and low sensitivity to reward showed a leftward asymmetry of directed attention when there was no informative spatial cue provided. This asymmetry was not present when targets were preceded by spatial cues that were either valid or invalid. The findings support the notion that individual variations in temperament influence spatial asymmetries in visual orienting, but only when lateral targets are preceded by a non-directional (neutral) cue. The results are discussed in terms of hemispheric asymmetries and dopamine activity. (shrink)

We investigate individual, developmental, and cultural differences in self-control in relation to children's changing belief in “free will” – the possibility of acting against and inhibiting strong desires. In three studies, 4- to 8-year-olds in the U.S., China, Singapore, and Peru (N = 441) answered questions to gauge their belief in free will and completed a series of self-control and inhibitory control tasks. Children across all four cultures showed predictable age-related improvements in self-control, as well as changes in their free (...) will beliefs. Cultural context played a role in the timing of these emerging free will beliefs: Singaporean and Peruvian children's beliefs changed at later ages than Chinese and U.S. children. Critically, culture moderated the link between self-control abilities and free will beliefs: Individual differences in self-control behaviors were linked to individual differences in free will beliefs in U.S. children, but not in children from China, Singapore or Peru. There was also evidence of a causal influence of self-control performance on free will beliefs in our U.S. sample. In Study 2, a randomly assigned group of U.S. 4- and 5-year-olds who failed at two self-control tasks showed reduced belief in free will, but a group of children who completed free will questions first did not show changes to self-control. Together these results suggest that culturally-acquired causal-explanatory frameworks for action, along with observations of one's own abilities, might influence children's emerging understanding of free will. (shrink)

Three experiments explore the role of working memory in motor skill acquisition and performance. Traditional theories postulate that skill acquisition proceeds through stages of knowing, which are initially declarative but later procedural. The reported experiments challenge that view and support an independent, parallel processing model, which predicts that procedural and declarative knowledge can be acquired separately and that the former does not depend on the availability of working memory, whereas, the latter does. The behaviour of these two processes was manipulated (...) by providing or withholding visual (and auditory) appraisal of outcome feedback. Withholding feedback was predicted to inhibit the use of working memory to appraise success and, thus, prevent the formation of declarative knowledge without affecting the accumulation of procedural knowledge. While the first experiment failed to support these predictions, the second and third experiments demonstrated that procedural and declarative knowledge can be acquired independently. It is suggested that the availability of working memory is crucial to motor performance only when the learner has come to rely on its use. (shrink)

IntroductionPrevious transcranial magnetic stimulation studies have revealed that the activity of the primary motor cortex ipsilateral to an active hand plays an important role in motor control. The aim of this study was to investigate whether the ipsi-M1 excitability would be influenced by goal-directed movement and laterality during unilateral finger movements.MethodTen healthy right-handed subjects performed four finger tapping tasks with the index finger: simple tapping task, Real-word task, Pseudoword task, and Visually guided tapping task. In the Tap task, the subject (...) performed self-paced simple tapping on a touch screen. In the real-word task, the subject tapped letters displayed on the screen one by one to create a Real-word. Because the action had a specific purpose, this task was considered to be goal-directed as compared to the Tap task. In the Pseudoword task, the subject tapped the letters to create a pseudoword in the same manner as in the Real-word task; however, the word was less meaningful. In the VT task, the subject was required to touch a series of illuminated buttons. This task was considered to be less goal-directed than the Pseudoword task. The tasks were performed with the right and left hand, and a rest condition was added as control. Single- and paired-pulse TMS were applied to the ipsi-M1 to measure corticospinal excitability and short- and long-interval intracortical inhibition in the resting first dorsal interosseous muscle.ResultsWe found the smaller SICI in the ipsi-M1 during the VT task compared with the resting condition. Further, both SICI and LICI were smaller in the right than in the left M1, regardless of the task conditions.DiscussionWe found that SICI in the ipsi-M1 is smaller during visual illumination-guided finger movement than during the resting condition. Our finding provides basic data for designing a rehabilitation program that modulates the M1 ipsilateral to the moving limb, for example, for post-stroke patients with severe hemiparesis. (shrink)

Neurulation, the curling of the neuroepithelium to form the neural tube, is an essential component of the development of animal embryos. Defects of neural tube formation, which occur with an overall frequency of one in 500 human births, are the cause of severe and distressing congenital abnormalities. However, despite the fact that there is increasing information from animal experiments about the mechanisms which effect neural tube formation, much less is known about the fundamental causes of neural tube defects (NTD). The (...) use of computer models provides one way of gaining clues about the ways in which neurulation may be compromised. Here we employ one computer model to examine the robustness of different cellular mechanisms which are thought to contribute to neurulation. The model, modified from that of Odell et al (Odell, G.M., Oster, G., Alberch, P. and Burnside, B., (1981)) mimics neurulation by laterally propagating a wave of apical contraction along an active zone within a ring of cells. We link the results to experimental evidence gained from studies of embryos in which neurulation has been perturbed. The results indicate that alteration of one of the properties of non-neural tissue can delay or inhibit neurulation, supporting the idea, gained from observation of embryos bearing genes which predispose to NTD, that the tissue underlying the neuroepithelium may contribute to the elevation of the neural folds. The results also show that reduction of the contractile properties of a small proportion of the neuroepithelial cell population may have a profound effect on overall tissue profiling. The results suggest that the elevation of the neural folds, and hence successful neurulation, may be vulnerable to relatively minor deficiencies in cell properties. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Platonic Ethics: Old and NewEve Browning ColeJulia Annas. Platonic Ethics: Old and New. Ithaca, NY: Cornell University Press, 1999. Pp. vii + 196. Cloth, $35.00Readers of Plato's dialogues in our time are almost unanimously affected by what Annas here calls "the developmental thesis." We bring to Plato's texts as a dogma the [End Page 114] view that his doctrines evolved over time, that later dialogues return to problems (...) unsuccessfully addressed in earlier dialogues, and in short that the Platonic corpus as a whole should be arranged as a kind of intellectual "Bildungsroman." The early and inconclusive explorations of Socrates give way to mature and expansive metaphysical doctrines, which in turn are tested and revised in subsequent works.This developmentalist dogma has dominated interpretations of Plato, with few exceptions (notably Paul Shorey), for a century and more. Yet this makes it a rather young dogma after all. Annas argues that it is a product of Victorian scholars, and especially targets the highly influential work of Benjamin Jowett (95 n.56). Jowett placed the Republic at the center of Plato's works and interpreted others backward and forward from it. The influence of this developmental thesis has been sweeping and, Annas argues, unfortunate. Armed with it, we are reluctant to consider the doctrines of the dialogues on their own terms; we make problems for one dialogue with concerns expressed in quite another; we tend to force our readings to fit the progressive picture and distort the works in the process.To achieve some distance from developmentalism and other modern preconceptions and dogma, Annas proposes listening with an open mind to ancient readings of Plato, especially those of the so-called Middle Platonists. Most modern students of ancient philosophy have been accustomed to discount these ancients as either too marginal to deserve a hearing or too biased to be fair readers. (In addition, access to their works in reliable texts and translations has been impossible until quite recently.)But such ancient readers as Albinus, Alcinous, Arius Didymus, Philo, and Numenius have (Annas argues) much to offer.First, they are active participants in an ongoing intellectual conversation about "eudaimonism," or the sufficiency of virtue for happiness. They comfortably engage Plato in this conversation as a proponent of eudaimonism. This is as true for the Plato of Republic and Laws as for the earlier dialogues. These older readers of Platonic ethics demonstrate that it is indeed possible to discern a unified view of the relation between goodness and happiness, without violence to the texts. While Plato may speak with "many voices," as Arius Didymus averred, this does not entail that he held "many doctrines" (9).Another modern shibboleth which the older readers can help us dislodge concerns the proper understanding of the Republic. We have tended to classify it as political theory (and in this are supported by the Library of Congress, as Annas points out). While recognizing the hefty core of more individual ethical thinking which goes into the definition of justice in the soul, we have insisted that the "Fairest City" is a serious utopian project description and should shape and contain the Republic's ethical teachings. Here too the ancients were much less inhibited than we; most of them cheerfully ignore the city-building and attend mainly to the implications for moral life. Annas finds this not only salubrious and unity-supporting but more faithful to the text, whose political content she finds "brief and underdeveloped" (82).Many readers will find the treatment of Republic's political significance (or lack thereof) objectionable. Many readers will also find the idea of relinquishing developmentalism to be unappealing or even frightening. But Annas makes a strong case for [End Page 115] seriously consulting the ancient readers if only for their medicinal value; they can "... wake us from our developmental slumbers" (165). Moreover, she provides a friendly and accessible entree to their world, one which will be of value to many modern readers who have been mystified by them heretofore.All texts quoted are in translation, and the occasional bits of original texts are transliterated. An extremely helpful "cast of characters" (which everyone will be tempted to xerox and... (shrink)

EEGs were analyzed to investigate the effect of experiences in listening to preferred music in dancers and non-dancers. Participants passively listened to instrumental music of their preferred genre for 2 min, alternate genres, and silence. Both groups showed increased activity for their preferred music compared to non-preferred music in the gamma, beta, and alpha frequency bands. The results suggest all participants' conscious recognition of and affective responses to their familiar music, appreciation of the tempo embedded in their preferred music and (...) emotional arousal, and enhanced attention mechanism for cognitive operations such as memory retrieval. The observed alpha activity is considered in the framework of the alpha functional inhibition hypothesis, in that years of experience listening to their favorite type of music may have honed the cerebral responses to achieve efficient cortical processes. Analyses of the electroencephalogram activity over 100s-long music pieces revealed a difference between dancers and non-dancers in the magnitude of an initial alpha event-related desynchronization and the later development of an alpha event-related synchronization for their preferred music. Dancers exhibited augmented alpha ERD, as well as augmented and uninterrupted alpha ERS over the remaining 80s. This augmentation in dancers is hypothesized to be derived from creative cognition or motor imagery operations developed through their dance experiences. (shrink)

Previous research on the neural basis of cognitive control processes has mainly focused on cortical areas, while the role of subcortical structures in cognitive control is less clear. Models of basal ganglia function as well as clinical studies in neurodegenerative diseases suggest that the striatum (putamen and caudate nucleus) modulates the inhibition of interfering responses and thereby contributes to an important aspect of cognitive control, namely response interference control. To further investigate the putative role of the striatum in the (...) control of response interference, 23 patients with stroke-induced lesions of the striatum and 32 age-matched neurologically healthy controls performed a unimanual version of the Simon task. In the Simon task, the correspondence between stimulus location and response location is manipulated so that control over response interference can be inferred from the reaction time costs in incongruent trials. Results showed that stroke patients responded overall slower and more erroneous than controls. The difference in response times (RTs) between incongruent and congruent trials (known as the Simon effect) was smaller in the ipsilesional/-lateral hemifield, but did not differ significantly between groups. However, in contrast to controls, stroke patients exhibited an abnormally stable Simon effect across the reaction time distribution indicating a reduced efficiency of the inhibition process. Thus, in stroke patients unilateral lesions of the striatum did not significantly impair the general ability to control response interference, but led to less efficient selective inhibition of interfering responses. (shrink)

Newton’s Opticks was in no way directed at artists, but the great prestige of its author, as well as its proposal of possible principles of color-harmony, and its establishment of the circle as the most graphic format for illustrating color-relationships, ensured the book a place in the repertory of coloristic art-theory from the eighteenth century until the present day. And, although it was implicit rather than explicit in the Opticks, the idea of complementarity continued to fascinate painters well into the (...) twentieth century. But in painting, the long-standing focus on chiaroscuro as the essential basis of pictorial structure inhibited the acceptance of the notion that colors are inherent in light alone; and Newton’s theory failed to make much headway against the traditional Aristotelianism, which was revived most eloquently by Goethe at the close of the eighteenth century. It was only two centuries later, in the new light-based art of holography, that the Opticks again became a text to conjure with. (shrink)

The main objective of this study is to eliminate the obstacles that the stylistic, structural, and methodological aspects of the text place in the way of reading and understanding Ludwig Wittgenstein's later work. The characteristic features of these elements are developed and discussed in the context of a close reading of the short section on reading in the Philosophical Investigations. Wittgenstein's aim in this section is the negative one of completely undermining explanatory accounts of the meaning of reading in terms (...) of mental states, experiences, or neurophysiological functions of the brain. In this respect the section on reading forms a clearing ground and a propaedeutic to Wittgenstein's conception of understanding as a rule-following activity. ;The signature of Wittgenstein's style is characterized by a dialogic terseness, an economy of expressions manifest in the brevity of numbered remarks, and a number of strategically indirect rhetorical devices. The structure of the text is shown to be discontinuous and multidirectional. The textual organization forms an overlapping and complex network that mirrors the complexity and multifaceted structure of language. The discontinuity easily inhibits following Wittgenstein's thought, and results in a judgment and dismissal of the text as being fragmented, frayed, and thus lacking structure. ;Wittgenstein's method is contrasted to the application of the scientific method to solving philosophical problems and to the phenomenological method of examining experiences. The argument for the existence of a method at all consists in focussing on and developing three methodological principles: recalling the course of philosophical nonsense; reminding ourselves of what we already know; and arranging and rearranging what already lies open to view. ;Bringing philosophical problems to an end by exposing them as pseudo-problems that often are caused by the forms of our expressions, is reached by an Ubersicht, an overview, of the multiple facets of language. Such an overview is gained by an application of Wittingenstein's method. An analysis of the section on reading in terms of its philosophical purpose and point illuminates the complex interplay of the methodological aspects, the unconventional structure of the text, and the profile of Wittgenstein's unique philosophical style. (shrink)

continent. 1.2 (2011): 70-75. cartography of ghosts . . . And as a way to talk . . . of temporality the topography of imagination, this body whose dirty entry into the articulation of history as rapturous becoming & unbecoming, greeted with violence, i take permission to extend this grace —Akilah Oliver from “An Arriving Guard of Angels Thusly Coming To Greet” Our disappearance is already here. —Jacques Derrida, 117 I wrestled with death as a threshold, an aporia, a bandit, (...) a part of life. —Akilah Oliver Moraine in geological lingo is that which is left behind. Moraine- a euphemism for the de-stabilizing referent of the writer-ly body as a “troubled and troubling landscape marked by cultural and historical signifiers, the body as flesh memory [...] the body as transitory” (Oliver, Author Statement). Moraine— a geological metaphor of the poet as a holder of memory, as an accumulation of rocks and debris carried along the edge, terminal, dropped at the foot of language (in language). “Flesh Memory” according to Akilah Oliver is "that which my body recalls [...] everything has to do with the task of remembrance and its narrative reinvention [...] I was always translating an idea of the world as it presented itself at any given time. To write was a choice about how to be seen, how to enter the world as translator, actor, participant, in the dialogues that apparently made the real 'real'" (Levitsky). Flesh. Memory. The stuff some poems are made from. The stuff that gets abandoned, gleaned, and picked up by more flesh and memory. "My body, my life has always felt like a kaleidoscopic rip in the dominant fabric [...] has always been a dialogue with the impossible and the apparent” (Levitsky). The impossible-body or poet's body anticipates and performs (through language) an irretrievable death. IN APORIA I realized everything I must have been doing must have been Death. It was Christmas or Labor Day—a holiday—and every time you turned on the radio they said something like ‘four million’ or ‘going to die’.” — Andy Warhol I’m trying on egos, [a justification for the planet’s continuance]. Oh hello transgressor, you’ve come to collect utilitarian debts, humbling narrative space. Give me condition and wheatgrass, I his body disintegrating. I his body is ossification. Death my habit radius, yeah yeah. I his body can’t refuse this summons. I can’t get out this fucking room. Tell me something different about torture dear Trickster. Tell me about the lightness my mother told me to pick the one i love the best how it signals everything I ever wish to believe true just holy on my ship. I jump all over this house. this is it [what I thought is thought only, nothing more deceptive than]: I his body keeps thinking someone will come along, touch me. As like human or lima bean. I’m cradling you to my breast, you are looking out. A little wooden lion you & Peter carve on Bluff Street is quieting across your cheekbone. Not at all like the kind of terror found in sleep, on trembling grounds. It is yesterday now. I have not had a chance to dance in this century. Tonight I shall kill someone, a condition to remember Sunday morning. To think of lives as repetitions [rather than singular serial incarnations]. To understand your death is as exacerbating as trying to figure out why as schoolchildren in mid-nineteen-sixties Southern California we performed reflexive motions: cutting out lace snowflakes, reading Dick and Jane search for their missing mittens, imagining snow. Disintegrat ing . The -ing gerund catapults from the non-finite verb into past, present, future. The -ing as a tail pinned to death, a dog spinning to bite and never fully reaching itself, always shy of the end, circumreferential; a double copulative: deathing. Possessively AO calls it “habit radius” (a virtual fetish attribute) or an inescapable death presence that “confronts us with the paradox of an unattainable object [...] through it’s being unattainable” (Agamben, 27). A flirtation or dialogue with an unknowable thing and aporia utilized as investigative instrument to engage (death) while (in Southern California) we “perform reflexive motions,” cut lace snowflakes, imagine snow, and pay rent like “yeah, yeah” what else is new. And this too, fiction. The book I wish to right. The restored fallen, heroic. Did you expect a different grace from the world? Or upon exit? I’m working on “tough.” They think I am already. All ready. Who is the dead person? Is "I'm sorry" real to a dead person? Browning grass. My hands on this table. A contentious century. A place to pay rent. Redemptive moments. Am I now the dead person? Dead person, dead person, will you partake in my persimmon feast? The body inside the body astounds, confesses sins of the funhouse. I too have admired the people of this planet. Their frilly, orderly intellects. The use they’ve made of cardamom, radiation as well. How they’ve pasteurized milk, loaned surnames to stars, captured tribes, diseases, streets, and ideas too. The living-body as archive: is it possible to experience the living-body as archive without a (kind of) death? Sifting the rubble, rummaging through hoarded debris, skin sheds, memory-napping, and re-awoken (in flesh and) on terrain. “An investigative poetics seeks to unravel staid communities of thought and grasp at what might always be just beyond reach; a poetics of inquiry that lies between language as meaning, and language as rapturous entry into the world of posited ideas and idealism”( Levitsky). Something snaps. Lights blow out prior to embarking upon an investigative poetics. It begins with a question (often a sexy aporia) that leads to openings. "Every politics of memory [...] implies an intervention of the state. It's a state that legislates and acts with regard to the nonfinite mass of materials to be stored, materials which must be collected, preserved” (Derrida & Stiegler, 62). It seems poetic investigation already contains the potentiality of an (invisible) archive if the writer is “always writing” especially when not. Here’s my stupid digital romantic inclination: the living-body (of a poet) is a self-sustaining archive of non-finite memories. But not even I really believe that. AO innovated and sculpted an investigative poetic praxis. In a conversation with poet Rachel Levitsky, poetic-voice is viewed not as a precious identifier, but as a means to think through/about form, concluding that form is linked to framing. While poetic-voice may have tendency to precede form, it also erupts as a result of framing techniques. “They are frames that hold the shape of thinking (which is also to say of imagining) [...].”7 This reminds me of my rabbit who symmetrically chewed the corners of his hutch, which makes me wonder if it’s an expression of the shape of some animal anxiety tick I won’t ever have access to. Beyond the form/frame, death is an unoriginal yet unique limit; death is a damn deathless thing. It functions as a source of poetic investigation; that thing always “just beyond reach.” And how is death not a fetish (in this case an obsessive reverence for something non-material)? “Insofar as it [death] is a presence, a fetish [...] it is in fact something concrete and tangible; but insofar as it is the presence of an absence, it is, at the same time, immaterial and intangible, because it alludes continuously beyond itself to something that can never really be possessed [...] The fetish is [...] a sign of an absence, it is not an unrepeatable unique object; on the contrary, it is something infinitely capable of substitution, without any successive incarnations ever succeeding in exhausting the nullity of which it is the symbol” (Agamben, 33). AO utilized absence (the absent body [catapulted by the death of a beloved]) as an apparatus to investigate. In the process of conversing with absence or that which is absent, the absent body is affectionately objectified, incessantly summonsed back to a place of recognition, of objects, a desire for the absent body to remain intact while exiting the structural limits of grammar and syntax by moving into chant forms “to say what cannot be said” (Levitsky). from AN ARRIVING GUARD OF ANGELS THUSLY COMING TO GREET dear oluchi- the light is blinking rapidly on the black boxy machine. your room seems bigger than before and i am still planning to read some of those robert jordan books of yours. yesterday at the used bookstore where i was browsing the mysteries to “stall reality” (they are really not mysteries at all, they just employ death as the plot mistress but are unable to grasp its mystery at all)—well the point is, things were calm down here for a while and the world was little. i want to be big like you. or i want you not vast, not dead, not gone, but human small and here. i am so selfish. that is what i really want. to see you again. to oil your scalp. to hear you walk in the door, say ma i’m home . give me a chance to say welcome home son. or when leaving, don’t forget your hat . what do you wear out there? i wish you could have taken your new shoes with you. i’m so proud of you. i’m sorry for the way you died. i miss you all the time. even before, i missed you. out there, one time, some different men said: “shake for me girl, i wanna be your backdoor man.” who dat you love. 5/18/03 A letter-poem in sixteen lines “dear oluchi-” is safe-housed in epistolary form. Poetic voice is rendered as internal thought meanderings, a not-so-much confession, private/(pillow?) talk in the desire to be heard/witnessed by the referent and reader with an intent to absolve. The diminutive “i” bears a relation to poet Fanny Howe’s “little g God” in that “One of the (many) things I like about little g God is that you can have a vodka tonic while you talk to little g God, sing along to Bowie’s “I’m Afraid Of Americans,” and hum Coltrane’s “A Love Supreme,” though maybe not all at the same time” (Oliver, 2009). Towards the middle of the poem AO is at a used bookstore and remarks on the funny employment of death as a ‘plot mistress’ that ‘they’ (the dubious employed mystery authors) are ‘unable to grasp’, thereby giving death a mouthpiece, a modeling job, something to do to pass the time. from THE VISIBLE UNSEEN When I first saw graffiti, I recognized in it an ugly aesthetic, a dialectics of violence, a distortion of limbs, a hieroglyph. It was only later when I read the names of the dead that I then saw the path of ghosts charted there; its narrative of loss for the visible unseen whose place in history has been fictionalized and rendered unseen under the totalizing glare of history. Inscriptions, traces, specters. Graffiti begs a public face just as ghosts require non-ghosts (humans) to sense them. The “visible unseen” is a game of hide-and-seek between public viewer and graffiti-inscriber, an ephemeral-violent aesthetic on an ephemeral-policed canvas. Graffiti-inscribers already submit to being forgotten, expect to be washed away; perhaps it’s a holy urban mandala created by gangster-type monks without Buddhism. [...] in its refusal to disappear it forces a discourse in the public imagination we are forced to see what we would rather not, to make sense of an encoded language that we cannot read on the level of meaning. it irritates, forces its agency on us, speaks outside and beyond semiotic reach. An epic font-size pervading the public’s imagination, illegible, I could just close my eyes, remain passive, drive past, abandon it beyond reach, push it further away beyond death walls. In Barcelona I watched a clean up crew wash walls with an awesome water hose but I was more intrigued by their bodies; not a distortion of limbs, not hieroglyph but also not entirely legible; the laboring body permanently erasing specters of the city, and of course they knew it was also an invitation for the ghosts to return. Graffiti is death’s little sister, is also an aporia. [...] Graffiti (fr GK -graph(os), something drawn or written, to diagram or chart) attempts to stage the impossible: to erase the essence of its own subjectivity. Graffiti is a cartography of ghosts, a mapping of elegiac rapture (the transporting of a person from one place to another, as in heaven) and rupture (the state of being broken open.) Dwelling is a fiction stasis. [...] The notion of the past as being something done with, a look-back event, inhibits the possibility of reading graffiti as rapture, as rupture. If graffiti posits history as always in the process of becoming undone. [...] Because what is the body, if not also a complex temple, an unstable site through which to negotiate subjects, materiality, economies, gods, and modes of representations? The site where we are all already belated. Graphein meaning “to write.” “Derrida says every archive makes a law, and the law of genre is its own rupture” (Bloch, 39). However, graffiti is an (non/anti)-archive of erasure due to (the politics of) washing out its subjectivity, which only adds onto (or is symptomatic of) its character. The inhibition of “reading graffiti as rapture, as rupture” is partly due to it being a “look-back” event in that it’s process involves scratching through layers to reveal previous specters underneath. Graffiti (as an ancient genre) has always been a thing of ‘becoming undone’, and therefore ‘belated and always in arrival’ (Levitsky). It’s a Dionysian activity done at night with it’s back turned toward us. "The specter [...] is of the visible, but of the invisible visible, it is the visibility of a body which is not present in flesh and blood [...] appearing for vision, to the brightness of day [...] something becomes almost visible which is visible only insofar as it is not visible in flesh and blood. It is a night visibility. As soon as there is a technology of the image, visibility brings night. It incarnates in a night body, it radiates in a night light" (Derrida & Stiegler, 115). (shrink)

The aging process involves changes in immune regulation, i.e. adaptive immunity declines whereas innate immunity becomes activated. NF‐κB signaling is the master regulator of the both immune systems. Two recent articles highlight the role of the NF‐κB system in aging and immune responses. Adler et al1 showed that the NF‐κB binding domain is the genetic regulatory motif which is most strongly associated with the aging process. Kwon et al2 studying HIV‐1 infection and subsequent immune deficiency process demonstrated that HIV‐1 Tat (...) protein binds to SIRT1 protein, a well‐known longevity factor, and inhibits the SIRT1‐mediated deacetylation of the p65 component of the NF‐κB complex. As a consequence, the transactivation efficiency of the NF‐κB factor was greatly potentiated, leading to the activation of immune system and later to the decline of adaptive immunity. These observations support the scenario where immune responses and aging process can be enforced by the potentiation of NF‐κB transactivation efficiency. Longevity factors, such as SIRT1 and its activators, might regulate the efficiency of the NF‐κB signaling, the major outcome of which is inflamm‐aging via proinflammatory responses. BioEssays 30:939–942, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Representation and the Mind-Body Problem in Spinoza by Michael Della RoccaWilliam SackstederMichael Della Rocca. Representation and the Mind-Body Problem in Spinoza. New York: Oxford University Press, 1996. Pp xiv + 223. Cloth, $39.95.A first virtue in elucidating any great philosopher is stating exactly the project the commentator undertakes, showing what is to be concluded, and how, and what of necessity must be omitted. Here, Della Rocca’s success is (...) exemplary.I cannot do better than to paraphrase, with running quotations, his remarkably succinct preliminaries. He undertakes two problems “crucial to Spinoza’s philosophy of mind,” first, “the requirement for having a thought about a particular object,” and second, “the traditional problem of whether or not the mind is identical with the body.” These inquiries are to be interconnected systematically by showing their dependence on Spinoza’s “denial of causal or explanatory or conceptual relations between the mental and the physical.”With exceptions I note later, the nine chapters of this book follow precisely. Chapter 1 prepares basic concepts and claims, along with formulation of the principle indicated, now called “the barrier between thought and extension.” Chapters 2 through 5 present and question Spinoza’s “theory of representation” (the first problem, as in the title) with its consequences respecting the announced principle. Chapters 7 and 8 turn to insights on “the mind-body problem” (the second problem), as illuminated by these investigations and secured by the governing principle. Della Rocca tidily exemplifies ruling expository virtues, but I question whether this very exactitude does not inhibit a needed species of escapement. Any commentator is obliged to acknowledge and detach himself from his own assumptions, from mannerisms and jargon current in the profession, from his present status or mannered tics, and from accidental skewing subsequent to current practices of language and translation. For such commitments also govern his treatment and they may often occlude his or our understanding. Let me be picky in initial illustration. [End Page 136]On pages 25f., the author correctly warns about pitfalls occasioned by lack of articles, definite or indefinite, in Latin. Thus, as he is aware, both interpretation and translation are queasy and infected with responses and glosses insinuated by demands from our own language, especially our prevailing fondness for definite articles, for solidity, univocal designation, and instantiation. So far, so good. But I invite my readers here to reflect whether Della Rocca’s own pervasive use of the definite article in the quotations I indulged in surveying his task does not distort his whole conception of that project. Momentum from the word the converts issues and verbalisms entertained into furniture of the world.Perhaps even more insidiously, Della Rocca invokes a peculiar itemization whereby recent formulations impose “at least one” and “for any x” on all quantified inferential usages. Moderns need rather liberation from membership suggestions in set theory and its associated logic. His remarks about “extension” and “intension” help, but they do not remedy modernist ineptness regarding Spinoza’s use of ipse, per se, and in se. Further, like precision obscures care about subordinate and causal differentiations. A sort of subsumed merging under a unit whole simple in nature is dear to Spinoza, though such moves are uncongenial to us.My earlier account scanted chapters 6 and 9, which also follow from the basic project, though not as tidily. Chapter 6, “Falsity,” “solves certain thorny problems” in the account of that and its opposite; Chapter 9 gathers ruling materials to shed light on “substantive monism.” Their arrangement ought to assist our perplexities about involvement and simple grasp, whereas 6 is noticeably brief and 9 sketchy. Together, they scant (rather than illuminate) subtlety in Spinoza’s investigations of intellect and its involvment in the nature of things.Expository clarity also shows in current fashions for multiple cross-references between indented and numbered claims, paraphrases, inferential premisses, and glosses by others. But beyond hiding preference for propositional reductions, and beyond hindering smooth reflection, such dismemberment prejudices against modes of reasoning tracing “some certain sort of eternity” or “what is common to all and equally in part and whole.”Efforts to work rigorously with made-up words or adapted phrases only... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:What Impressions of Necessity? Antony Flew My question is this: "Why and how was it that Hume failed to find a kind ofimpression from which to legitimate the complementary ideas of physical necessity and physical impossibility?" We can best begin from his first published discussion of causation. 1. In Treatise 1.3.2, the section, "Ofprobability; and ofthe idea of cause and effect," Hume asserts that, "The idea... of causation must (...) be deriv'd from some relation among objects; and that relation we must now endeavour to discover."1 His first efforts are directed to establishing that two causally related objects must be both spatio-temporally contiguous and temporally successive, the cause object preceding the effect object. But "[h]aving thus discover'd or suppos'd" this conclusion, Hume finds that he is "stopt short, and can proceed no farther in considering any single instance of cause and effect" (T 76). We might, therefore, have expected that his next move wouldhavebeen to consider series ofresemblingcause objects and their relations to series ofresemblingeffect objects. But such a consideration is in fact deferred from section 2 until section 14, "Of the idea of necessary connection"; a section starting all of seventy-seven pages later. Instead, the immediately following paragraph reads: Shou'd any one leave this instance, and pretend to define a cause, by saying it is something productive of another, 'tis evident he wou'd say nothing. For what does he mean by production? Can he give any definition of it, that will not be the same with that of causation? Ifhe can; I desire it maybe produc'd. If he cannot; he here runs in a circle, and gives a synonimous term instead ofa definition. (T 77) The phrasing ofthat paragraph perhaps constitutes one of those infelicities in the Treatise which Hume was later to recognize and regret. For if and inasmuch as "causation" and "production" are synonyms, any adequate definition of either word must be equally adequate for both. Rashly assuming that his challenge toproduce such a definition will not and cannot be met, Hume proceeds at once to ask and to answer his own consequential question: Volume XVIII Number 2 169 ANTONY FLEW Shall we then rest contented with these two relations of contiguity and succession, as affording a compleat idea of causation? By no means. An object may be contiguous and prior to another, without being consider'd as its cause. There isa necessaryCONNEXION to be taken into consideration; and that relation is of much greater importance, than any of the other two above-mention'd. (T 77) 2. But now, why "necessary connexion" rather than either "causal connexion" or "connexion" without prefix or suffix? Suppose that you were the Adam of the Abstract "created in the full vigour of understanding," yet altogether "without experience." (T 650). And suppose that you had noticed some A's both spatio-temporally contiguous to and precedent to B's. Then, assuming that your understanding was not only vigorous but also equipped with all the essential concepts, you might well ask yourself, or perhaps, if she was now available, your partner, whether there was any causal connection here at all; or, more specifically, whether these A's were causing these B's. You might even proceed to put the question to experimental test: either by producing further A's in hopes ofconsequentially producing furtherB's; or, whenA's occurredspontaneously, by trying to inhibit the subsequent occurrence ofB's. What such an Adam would surely not do—not unless he had developed proto-Humean desires: both to demonstrate the absence here ofany logically necessary connections; and thus, hopefully, also to discredit theidea that anyotherkind ofnecessity might beinvolved—is to suggest that the third, crucial, and so far unidentified element in any adequate account of causation must be necessary connection; as opposed, that is, to either causal connection or just plain unqualified connection. It is, of course, obvious that Hume himselfis eager to get on first to denying logically necessary connections, and then to the further business which he relates to this denial. For it is in the immediately followingsection 3, "Whyacauseisalwaysnecessary," thathe presents his argument for the conclusion that, whereas, "Every effectmust... (shrink)