This article investigated the paradox between church response to apartheid and resulting action at the local level in the South African churches of European origin from the perspective of the Presbyterian Church of South(ern) Africa (PCSA). It indicated that this discrepancy arose between the reflections (cerebral faith) at the highest levels of church councils, which operated in an intermittent manner and at a distance, compared with the responses (praxis as faith in action) of local church members who lived at (...) the coalface of the struggle and sought to witness in a society dominated by racism, where the tension between faith and politics was most evident. The primary focus was on two inter-racial congregations, one of the PCSA, the other a united congregation in which the PCSA participated. This study used primary and secondary sources. The theoretical framework of the article was Thomas Groome’s approach of shared praxis.Contribution: This article contributed to the history of the apartheid era in ecclesiastical contexts. It demonstrated the anomalies that arose within different constituencies within churches of European origin by investigating the situation in one particular denomination. This was a discussion of the relationship of faith and politics in the private and public domains, which takes account of developments within a shared praxis approach. (shrink)

In the late 19th century, physiologists such as David Ferrier, Eduard Hitzig, and Hermann Munk argued that cerebral brain functions are localized in discrete structures. By the early 20th century, this became the dominant position. However, another prominent physiologist, Friedrich Goltz, rejected theories of cerebral localization and argued against these physiologists until his death in 1902. I argue in this paper that previous historical accounts have failed to comprehend why Goltz rejected cerebral localization. I show that Goltz (...) adhered to a falsificationist methodology, and I reconstruct how he designed his experiments and weighted different kinds of evidence. I then draw on the exploratory experimentation literature from recent philosophy of science to trace one root of the debate to differences in how the German localizers designed their experiments and reasoned about evidence. While Goltz designed his experiments to test hypotheses about the functions of predetermined cerebral structures, the localizers explored new functions and structures in the process of constructing new theories. I argue that the localizers relied on untested background conjectures to justify their inferences about functional organization. These background conjectures collapsed a distinction between phenomena they produced direct evidence for (localized symptoms) and what they reached conclusions about (localized functions). (shrink)

To assess the ability of the disconnected cerebral hemispheres to recognize images of the self, a split-brain patient was tested using morphed self-face images presented to one visual hemifield at a time while making “self/other” judgments. The performance of the right and left hemispheres of this patient as assessed by a signal detection method was not significantly different, though a measure of bias did reveal hemispheric differences. The right and left hemispheres of this patient independently and equally possessed the (...) ability to self-recognize, but only the right hemisphere could successfully recognize familiar others. This supports a modular concept of self-recognition and other-recognition, separately present in each cerebral hemisphere. (shrink)

Individuals with cerebral palsy (CP) have deficits in processing of somatosensory and proprioceptive information. To compensate for these deficits, they tend to rely on vision over proprioception in single plane upper and lower limb movements and in standing. It is not known whether this also applies to walking, an activity where the threat to balance is higher. Through this study, we used visual perturbations to understand how individuals with and without CP integrate visual input for walking balance control. Additionally, (...) we probed the balance mechanisms driving the responses to the visual perturbations. More specifically, we investigated differences in the use of ankle roll response i.e., the use of ankle inversion, and the foot placement response, i.e., stepping in the direction of perceived fall. Thirty-four participants (17 CP, 17 age-and sex-matched typically developing controls or TD) were recruited. Participants walked on a self-paced treadmill in a virtual reality environment. Intermittently, the virtual scene was rotated in the frontal plane to induce the sensation of a sideways fall. Our results showed that compared to their TD peers, the overall body sway in response to the visual perturbations was magnified and delayed in CP group, implying that they were more affected by changes in visual cues and relied more so on visual information for walking balance control. Also, the CP group showed a lack of ankle response, through a significantly reduced ankle inversion on the affected side compared to the TD group. The CP group showed a higher foot placement response compared to the TD group immediately following the visual perturbations. Thus, individuals with CP showed a dominant proximal foot placement strategy and diminished ankle roll response, suggestive of a reliance on proximal over distal control of walking balance in individuals with CP. (shrink)

I dispute that consciousness is generated by core circuitry in the forebrain, with predominance of motor areas, as Cotterillproposes in Enchanted Looms and other theorists do also. Ipropose instead that conscious contents are the momentary modeof action of the integrated cortical field, expressed as a point vector ( dominant focus ), to which, in varying degree, allsectors of the network contribute. Consciousness is the brain''saccess to its own activity space, and is identical with the moment''sdominant mode of activity. The dominant (...) focus is generally weightedtoward enactively encoded percepts. Anticipation and preparation,perception and action, inextricably interdigitate. I also dispute the view of Cotterill and others that consciousnesshas unique agency, which bestowed adaptive advantage when the brain evolved. Being identical with the activity of the network,consciousness can have no additional agency, and it can offerno adaptive advantages beyond those that characterize the network. (shrink)

ObjectiveThe correlation between the performance of coordination movement and brain activity is still not fully understood. The current study aimed to identify activated brain regions and brain network connectivity changes for several coordinated finger movements with different difficulty levels and to correlate the brain hemodynamics and connectivity with kinematic performance.MethodsTwenty-one right-dominant-handed subjects were recruited and asked to complete circular motions of single and bilateral fingers in the same direction and in opposite directions on a plane. Kinematic data including radius and (...) angular velocity at each task and synchronized blood oxygen concentration data using functional near-infrared spectroscopy were recorded covering six brain regions including the prefrontal cortex, motor cortex, and occipital lobes. A general linear model was used to locate activated brain regions, and changes compared with baseline in blood oxygen concentration were used to evaluate the degree of brain region activation. Small-world properties, clustering coefficients, and efficiency were used to measure information interaction in brain activity during the movement.ResultIt was found that the radius error of the dominant hand was significantly lower than that of the non-dominant hand in both clockwise and counterclockwise movements. The fNIRS results confirmed that the contralateral brain region was activated during single finger movement and the dominant motor area was activated in IP movement, while both motor areas were activated simultaneously in AP movement. The Δhbo were weakly correlated with radius errors. Brain information interaction in IP movement was significantly larger than that from AP movement in the brain network in the right prefrontal cortex. Brain activity in the right motor cortex reduces motor performance, while the right prefrontal cortex region promotes it.ConclusionOur results suggest there was a significant correlation between motion performance and brain activation level, as well as between motion deviation and brain functional connectivity. The findings may provide a basis for further exploration of the operation of complex brain networks. (shrink)

Although gestures have surface similarities with language, there are significant organisational and neurolinguistic differences that argue against the evolutionary connection proposed by Corballis. Dominance for language and handedness may be related to a basic specialisation of the left cerebral hemisphere for target-directed behaviour and sequential processing, with the right side specialised for holistic-environmental monitoring and spatial processing.

This paper focuses on the inheritance of human handedness and cerebral lateralization within the more general context of structural biological asymmetries. The morphogenesis of asymmetrical structures, such as the heart in vertebrates, depends upon a complex interaction between information coded in the cytoplasm and in the genes, but the polarity of asymmetry seems to depend on the cytoplasmic rather than the genetic code. Indeed it is extremely difficult to find clear-cut examples in which thedirectionof an asymmetry is under genetic (...) control. As one possible case, there is some evidence that the direction, clockwise or counterclockwise, of rotation of the abdomen in certain mutant strains ofDrosophilais controlled by a particular gene locus, although there appears to be some degree of confusion on this point. By contrast, it is much easier to find examples in which thedegreebut not the direction of asymmetry is under genetic control. For instance, there is a mutant strain of mice in which half of the animals displaysitus inversusof the viscera. The proportion has remained at one half despite many years of inbreeding, suggesting that the mutant allele effectively cancels the normalsitusand allows the asymmetry to be specified in random fashion.Although this account does not deny that the right hemisphere of humans may be the more specialized for certain functions, it does attribute a leading or dominant role to the left hemisphere (at least in most individuals). We suggest that so-called “right-hemisphere” functions are essentially acquired by default, due to the left hemisphere's prior involvement with speech and skilled motor acts; we note, for instance, that these right-hemisphere functions include rather elementary perceptual processes. But perhaps the more critical prediction from our account is that the phenomenon of equipotentiality should be unidirectional: the right (lagging) hemisphere should be more disposed to take over left-hemisphere functions following early lesions than is the left (leading) hemisphere to take over right-hemisphere functions. We note preliminary evidence that this may be so. (shrink)

The strong predominance of right-handedness appears to be a uniquely human characteristic, whereas the left-cerebral dominance for vocalization occurs in many species, including frogs, birds, and mammals. Right-handedness may have arisen because of an association between manual gestures and vocalization in the evolution of language. I argue that language evolved from manual gestures, gradually incorporating vocal elements. The transition may be traced through changes in the function of Broca's area. Its homologue in monkeys has nothing to do with vocal (...) control, but contains the so-called “mirror neurons,” the code for both the production of manual reaching movements and the perception of the same movements performed by others. This system is bilateral in monkeys, but predominantly left-hemispheric in humans, and in humans is involved with vocalization as well as manual actions. There is evidence that Broca's area is enlarged on the left side in Homo habilis, suggesting that a link between gesture and vocalization may go back at least two million years, although other evidence suggests that speech may not have become fully autonomous until Homo sapiens appeared some 170,000 years ago, or perhaps even later. The removal of manual gesture as a necessary component of language may explain the rapid advance of technology, allowing late migrations of Homo sapiens from Africa to replace all other hominids in other parts of the world, including the Neanderthals in Europe and Homo erectus in Asia. Nevertheless, the long association of vocalization with manual gesture left us a legacy of right-handedness. Key Words: cerebral dominance; gestures; handedness; hominids; language evolution; primates; speech; vocalization. (shrink)

An exploration of our fall from the pinnacle of human evolution 200,000 years ago and how we can begin our return. Explores recent neurological and psychological research on the brain and the role of plant biochemistry in human brain expansion. Explains how humanity's prehistoric diet change led to a neurodegenerative condition characterized by aggression and a fearful perception of the world. Outlines a strategy of raw foods, tantric sexuality, shamanic practices, and entheogens to reverse our mental degeneration and restore our (...) advanced abilities. Over a period of a million years the human brain expanded at an increasingly rapid rate, and then, 200,000 years ago, the expansion abruptly stopped. Modern science has overlooked this in order to maintain that we are at the pinnacle of our evolution. However, the halt in brain expansion explains not only recently uncovered anomalies within the human brain but also the global traditions of an earthly paradise lost and of humanity's degeneration from our original state of perpetual wonder and joy. Drawing on more than 20 years of research, authors Tony Wright and Graham Gynn explore how our modern brains are performing far below their potential and how we can unlock our higher abilities and return to the euphoria of Eden. They explain how for millions of years early forest-dwelling humans were primarily consuming the hormone-rich sex organs of plants--fruit--each containing a highly complex biochemical cocktail evolved to influence DNA transcription, rapid brain development, and elevated neural and pineal gland activity. Citing recent neurological and psychological studies, the authors explain how the loss of our symbiotic fruit-based diet led to a progressive neurodegenerative condition characterized by aggressive behaviors, a fearful perception of the world, and the suppression of higher artistic, mathematical, and spiritual abilities. The authors show how many shamanic and spiritual traditions were developed to counteract our decline. They outline a strategy of raw foods, tantric sexuality, shamanic practices, and entheogen use to reverse our degeneration, restore our connection with the plant world, and regain the bliss and peace of the brain of Eden"--Provided by publisher. (shrink)

In "Consciousness Explained," Dennett (1991) denies that split-brain humans have double consciousness: he describes the experiments as "anecdotal." In attempting to replace the Cartesian Theatre of the Mind" with his own "Multiple Drafts" view of consciousness, Dennett rejects the notion of the mind as a countable thing in favour of its being a mere "abstraction." His criticisms of the standard interpretation of the split-brain data are analyzed here and each is found to be open to objections. There exist people who (...) have survived left ["dominant"] cerebral hemispherectomy; by Dennett's criteria, they would not have minds. (shrink)

Recent imaging results suggest that individuals automatically share the emotions of others when exposed to their emotions. We question the assumption of the automaticity and propose a contextual approach, suggesting several modulatory factors that might influence empathic brain responses. Contextual appraisal could occur early in emotional cue evaluation, which then might or might not lead to an empathic brain response, or not until after an empathic brain response is automatically elicited. We propose two major roles for empathy; its epistemological role (...) is to provide information about the future actions of other people, and important environmental properties. Its social role is to serve as the origin of the motivation for cooperative and prosocial behavior, as well as help for effective social communication. (shrink)

The concept of locally specialized functions dominates research on higher brain function and its disorders. Locally specialized functions must be complemented by processes that coordinate those functions, however, and impairment of coordinating processes may be central to some psychotic conditions. Evidence for processes that coordinate activity is provided by neurobiological and psychological studies of contextual disambiguation and dynamic grouping. Mechanisms by which this important class of cognitive functions could be achieved include those long-range connections within and between cortical regions that (...) activate synaptic channels via NMDA-receptors, and which control gain through their voltage-dependent mode of operation. An impairment of these mechanisms is central to PCP-psychosis, and the cognitive capabilities that they could provide are impaired in some forms of schizophrenia. We conclude that impaired cognitive coordination due to reduced ion flow through NMDA-channels is involved in schizophrenia, and we suggest that it may also be involved in other disorders. This perspective suggests several ways in which further research could enhance our understanding of cognitive coordination, its neural basis, and its relevance to psychopathology. Key Words: attention; cerebral cortex; cognitive coordination; cognitive neuropsychiatry; cognitive neuropsychology; context disorganization; Gamma rhythms; Gestalt theory; glutamate; grouping; memory; NMDA-receptors; PCP-psychosis; perceptual organization; schizophrenia. (shrink)

The acquisition and evolution of speech production, discourse and communication can be negatively impacted by brain malformations. We describe, for the first time, a case of developmental dynamic dysphasia (DDD) in a right-handed adolescent boy (subject D) with cortical malformations involving language-eloquent regions (inferior frontal gyrus) in both the left and the right hemispheres. Language evaluation revealed a markedly reduced verbal output affecting phonemic and semantic fluency, phrase and sentence generation and verbal communication in everyday life. Auditory comprehension, repetition, naming, (...) reading and spelling were relatively preserved, but executive function was impaired. Multimodal neuroimaging showed a malformed cerebral cortex with atypical configuration and placement of white matter tracts bilaterally and abnormal callosal fibers. Dichotic listening showed right hemisphere dominance for language and functional magnetic resonance imaging (fMRI) additionally revealed dissociated hemispheric language representation with right frontal activation for phonology and bilateral dominance for semantic processing. Moreover, subject D also had congenital mirror movements (CMM), defined as involuntary movements of one side of the body that mirror intentional movements of the other side. Transcranial magnetic stimulation and fMRI during voluntary unimanual (left and right) hand movements showed bilateral motor cortex recruitment and tractography revealed a lack of decussation of bilateral corticospinal tracts. Genetic testing aimed to detect mutations that disrupt the development of commissural tracts correlating with CMM (e.g., Germline DCC mutations) was negative. Overall, our findings suggest that DDD in subject D resulted from the underdevelopment of the left inferior frontal gyrus with limited capacity for plastic reorganization by its homologous counterpart in the right hemisphere. Corpus callosum anomalies probably contributed to hinder interhemispheric connectivity necessary to compensate language and communication deficits after left frontal involvement. (shrink)

I have provided evidence that Geary's model does not explain male dominance in spatial abilities by sexual selection. The current literature concerning the relations of nonverbal IQ to testosterone, hand preference, and right- and left-hand skill, as well as the organizing effects of testosterone on cerebral lateralization during the perinatal period, does not support Geary's arguments.

Cerebral energy supply is insufficient to support continuous neuronal processing of the plethora of time-constant objects that we are aware of. As a result, the brain is forced to limit processing resources to (the most relevant) cases ofchange. The neuronally generated world is thus temporally discontinuous. This parallels the fact that, in all relevant microscopic fundamental equations of nature, temporalchangeplays a dominant role. When a scientist calculates a “solution” to such an equation, integration over time is an essential step. (...) The present Hypothesis expresses that the step from neuronal activity to phenomenal content of consciousness is reflective of a (phenomenal) “solution:” the main source of the incomprehensibility of consciousness is proposed to result from the introduction of phenomenal time-constant entities. These are “filled-in”viaintegration, even though neuronal data only exists forchangesto these entities. In this way, a temporally continuous picture of the world phenomenally appears. Qualia are “initial conditions,” which are required for integration and cannot be deduced frompresentdata. Phenomenal “identity” (vs. “high similarity”) is related to qualia.Inattentivevisual perception, which is only rarely investigated, offers insights into these relationships. Introspectively, unattended vision appears rich because percepts are cumulated over long time spans, whereas attentive perception relies purely onpresentneuronal signals. The present Hypothesis is that a brief neuronal activity cansignifylong-lasting and constant phenomenal content of consciousness. Experimental support is presented that comes from discrepancies between neuronal activity and perception: transient neuronal responses to sustained stimuli, “filling-in,” change blindness, identity vs. close resemblance. (shrink)

Recent work in cerebral neurology should be used to fashion a new synthesis with anthropological studies. Beginning with Paul D. Madean's model of the triune brain, we explore Ralph Wendell Burhoe's question whether creative processes result from a coadaptation, perhaps in ritual itself, of genetic and cultural information. Then we examine the division of labor between right and left cerebral hemispheres and its implications for the notions of play and “ludic recombination.” Intimately related to ritual, play may function (...) in the social construction of reality analogous to mutation and variation in organic evolution. Finally, we consider how our picture of brain functioning accords with some distinctive features of the religious systems dominant in human cultures. (shrink)

A review of research with chicks, songbirds, rodents, and nonhuman primates indicates that the brain is lateralized for a number of behavioral functions. These findings can be understood in terms of three hypothetical brain processes derived from a brain model based on general systems theory: hemispheric activation, interhemispheric inhibition, and interhemispheric coupling.Left-hemisphere activation occurs in songbirds and nonhuman primates in response to salient auditory or visual input, or when a communicative output is required. The right hemisphere is activated in rats (...) when spatial performance is required, and in chicks when they are placed in an emotion-provoking situation. In rats and chicks interhemispheric activation and inhibition occur when there is an affective component in the environment (novelty, aversive conditioning) or when an emotional response is emitted (copulation, attack, killing). An interhemispheric coupling (correlation) found in rats and rabbits implies that the hemispheres are two major components in a control system with a negative feedback loop. Early-experience variables in rats can induce laterality in a symmetric brain or facilitate its development in an already biased brain.It is predicted that functional lateralization, when present, will be similar across species: the left hemisphere will tend to be involved in communicative functions while the right hemisphere will respond to spatial and affective information; both hemispheres will often interact via activation-inhibition mechanisms when affective or emotional processes are involved. Homologous brain areas and their connecting callosal fibers must be intact at birth and must remain intact throughout development for lateralization to reach its maximum level. Injury to any portion of this unit will result in hemispheric redundancy rather than specialization. One major function of early experience is to provide stimulation during development, which acts to enhance the growth and development of the corpus callosum, thereby giving rise to a more specialized brain. (shrink)

In this commentaryI evaluate the claim made byKeenan, Nelson, OÕConnor, and Pascual-Leone (2001) that since self-recognition results from right hemispheric activity, self-awareness too is likely to be produced by the activity of the same hemisphere. This reasoning is based on the assumption that self-recognition represents a valid operationalization of self-awareness; I present two views that challenge this rationale. Keenan et al. also support their claim with published evidence relating brain activityand self-awareness; I closelyexamine their analysis of one specific review of (...) literature and conclude that it appears to be biased. Finally, recent research suggests that inner speech (which is associated with left hemispheric activity) is linked to self-awareness—an observation that further casts doubt on the existence of a right hemispheric self-awareness. Ó 2002 Elsevier Science (USA). All rights reserved. (shrink)

In the last 50 years, discussions of how to understand disability have been dominated by the medical and social models. Paradoxically, both models overlook the disabled person’s experience of the lived body, thus reducing the body of the disabled person to a physiological body. In this article we introduce what we call the Ecological-Enactive (EE) model of disability. The EE-model combines ideas from enactive cognitive science and ecological psychology with the aim of doing justice simultaneously to the lived experience of (...) being disabled, and the physiological dimensions of disability. More specifically, we put the EE model to work to disentangle the concepts of disability and pathology. We locate the difference between pathological and normal forms of embodiment in the person’s capacity to adapt to changes in the environment. To ensure that our discussion remains in contact with lived experience, we draw upon phenomenological interviews we have carried out with people with Cerebral Palsy. (shrink)

Tests of models of reciprocal interactions of testosterone and behaviour patterns in honour subcultures, if based on adult samples measured at a single point in time, would be aided by measures of behaviour in such samples that indirectly index basal testosterone levels at earlier developmental ages, for example, hand preference and other measures of cerebral dominance. Such models raise questions about the social preconditions of honour subcultures, and their indirect effects on health.

This fine book tells an important story of how long-standing notions about the body as dominated by spirit-like humors were transformed into scientific descriptions of its solid tissues. Vesalius, Harvey, Descartes, Willis, and Locke all played roles in this transformation, as the cerebral hemispheres and cranial nerves began to take precedence over the role of spirit, passion, and the heart in human thought and behavior. Non of this occurred in a social vacuum, and the book describes the historical context (...) clearly. It also shows how debates over investigative methods and models of body order that first raged over 300 years ago continue to influence biomedicine and the broader culture today. No other book on western mind-body relationships has attempted this. (shrink)

'Updating Bertrand Russell for the 21st century... a cerebrally enjoyable survey, written with great clarity and touches of wit... The non-western section throws up some fascinating revelations' Sunday Times The story of philosophy is an epic tale: an exploration of the ideas, views and teachings of some of the most creative minds known to humanity. But since the long-popular classic Bertrand Russell's History of Western Philosophy, first published in 1945, there has been no comprehensive and entertaining, single-volume history of this (...) great intellectual journey. With his characteristic clarity and elegance A. C. Grayling takes the reader from the world-views and moralities before the age of the Buddha, Confucius and Socrates, through Christianity's dominance of the European mind to the Renaissance and Enlightenment, and on to Mill, Nietzsche, Sartre, and philosophy today. And, since the story of philosophy is incomplete without mention of the great philosophical traditions of India, China and the Persian-Arabic world, he gives a comparative survey of them too. Intelligible for students and eye-opening for philosophy readers, he covers epistemology, metaphysics, ethics, aesthetics, logic, the philosophy of mind, the philosophy of language, political philosophy and the history of debates in these areas of enquiry, through the ideas of the celebrated philosophers as well as less well-known influential thinkers. He also asks what we have learnt from this body of thought, and what progress is still to be made. The first authoritative and accessible single-volume history of philosophy for decades, remarkable for its range and clarity, this is a landmark work. (shrink)

Two meta-analyses of 66 behavioral studies examined variables influencing functional cerebral lateralization of each language of brain-intact bilingual adults. Functional lateralization was found to be primarily influenced by age of onset of bilingualism: bilinguals who acquired both languages by 6 years of age showed bilateral hemispheric involvement for both languages, whereas those who acquired their second language after age 6 showed left hemisphere dominance for both languages. Moreover, among late bilinguals, left hemisphere involvement was found to be greater for (...) those less proficient in their second language, those whose second language was English, and for studies involving dichotic listening paradigms; early bilinguals instead showed bilateral involvement in every condition. Implications of the observed differences in lateralization between early and late bilinguals are explored for existing theories of bilingualism and for neurocognitive models of brain functional organization of language. (shrink)

The presence of asymmetry in the human cerebral hemispheres is detectable at both the macroscopic and microscopic scales. The horizontal expansion of cortical surface during development (within individual brains), and across evolutionary time (between species), is largely due to the proliferation and spacing of the microscopic vertical columns of cells that form the cortex. In the asymmetric planum temporale (PT), minicolumn width asymmetry is associated with surface area asymmetry. Although the human minicolumn asymmetry is not large, it is estimated (...) to account for a surface area asymmetry of approximately 9% of the region’s size. Critically, this asymmetry of minicolumns is absent in the equivalent areas of the brains of other apes. The left-hemisphere dominance for processing speech is thought to depend, partly, on a bias for higher resolution processing across widely spaced minicolumns with less overlapping dendritic fields, whereas dense minicolumn spacing in the right hemisphere is associated with more overlapping, lower resolution, holistic processing. This concept refines the simple notion that a larger brain area is associated with dominance for a function and offers an alternative explanation associated with “processing type.” This account is mechanistic in the sense that it offers a mechanism whereby asymmetrical components of structure are related to specific functional biases yielding testable predictions, rather than the generalization that “bigger is better” for any given function. Face processing provides a test case – it is the opposite of language, being dominant in the right hemisphere. Consistent with the bias for holistic, configural processing of faces, the minicolumns in the right-hemisphere fusiform gyrus are thinner than in the left hemisphere, which is associated with featural processing. Again, this asymmetry is not found in chimpanzees. The difference between hemispheres may also be seen in terms of processing speed, facilitated by asymmetric myelination of white matter tracts ( Anderson et al., 1999 found that axons of the left posterior superior temporal lobe were more thickly myelinated). By cross-referencing the differences between the active fields of the two hemispheres, via tracts such as the corpus callosum, the relationship of local features to global features may be encoded. The emergent hierarchy of features within features is a recursive structure that may functionally contribute to generativity – the ability to perceive and express layers of structure and their relations to each other. The inference is that recursive generativity, an essential component of language, reflects an interaction between processing biases that may be traceable in the microstructure of the cerebral cortex. Minicolumn organization in the PT and the prefrontal cortex has been found to correlate with cognitive scores in humans. Altered minicolumn organization is also observed in neuropsychiatric disorders including autism and schizophrenia. Indeed, altered interhemispheric connections correlated with minicolumn asymmetry in schizophrenia may relate to language-processing anomalies that occur in the disorder. Schizophrenia is associated with over-interpretation of word meaning at the semantic level and over-interpretation of relevance at the level of pragmatic competence, whereas autism is associated with overly literal interpretation of word meaning and under-interpretation of social relevance at the pragmatic level. Both appear to emerge from a disruption of the ability to interpret layers of meaning and their relations to each other. This may be a consequence of disequilibrium in the processing of local and global features related to disorganization of minicolumnar units of processing. (shrink)