The concepts of hope and its absence, hopelessness, are seen as crucial in palliative care for people with motor neurone disease. A primary measure in psychological research on hopelessness in people with motor neurone disease is the Beck Hopelessness Scale. This scale can be understood as being conceptually based on the philosophical standard account of hope, which understands hope as an intentional expectancy. This essay argues that this is a misconstruction of hopelessness in palliative care. Rather, pre-intentional hope is essential (...) for palliative care of people with motor neurone disease. Pre-intentional hope enables the formation of intentional hopes and is intrinsically relational. Finally, it is argued that the absence of pre-intentional hope should not be subjected to psychiatric diagnosis, for example, in the form of demoralization disorder. (shrink)

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disorder of motor neurones. Although the genetic basis of familial forms of ALS has been well explored, the molecular basis of sporadic ALS is less well understood. Recent evidence has linked sporadic ALS with the failure to edit key residues in ionotropic glutamate receptors, resulting in excessive influx of calcium ions into motor neurones which in turn triggers cell death. Here we suggest that edited AMPA glutamate (GluR2) receptor subunits serve as gatekeepers (...) for motor neurone survival. BioEssays 30:1185–1192, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

This paper focuses on the ethical dilemmas created by advanced technology that would allow patients with motor neurone disease to be sustained by artificial ventilation. The author attempts to support the patient's right to informed choice, arguing from the perspective of autonomy as a first order principle. The counter arguments of caregiver burden and financial restraints are analysed. In the UK, where active euthanasia is not legalized, the dilemma of commencing ventilation is seen to be outweighed by the problems of (...) withdrawing this treatment. The lack of accurate data and protocols that would clarify the current situation is emphasized and the conclusion takes the form of a recommendation for further research. (shrink)

A central issue of cognitive neuroscience is to understand how a large collection of coupled neurons combines external signals with internal memories into new coherent patterns of meaning. An external stimulus localized at some input spreads over a large assembly of coupled neurons, building up a collective state univocally corresponding to the stimulus. Thus, the synchronization of spike trains of many individual neurons is the basis of a coherent perception. Based on recent investigations of homoclinic chaotic systems and their synchronization, (...) a novel conjecture for the dynamics of single neurons and, consequently, for neuron assemblies is formulated. Homoclinic chaos is proposed as a suitable way to code information in time by trains of equal spikes occurring at apparently erratic times. In order to classify the set of different perceptions, the percept space can be given a metric structure by introducing a distance measure between distinct percepts. The distance in percept space is conjugate to the duration of the perception in the sense that an uncertainty relation in percept space is associated with time-limited perceptions. This coding of different percepts by synchronized spike trains entails fundamental quantum features which are not restricted to microscopic phenomena. It is conjectured that they are related to the details of the perceptual chain rather than depending on Planck's action. (shrink)

It is widely held that a successful theory of the mind will be neuroscientific. In this paper we ask, first, what this claim means, and, secondly, whether it is true. In answer to the first question, we argue that the claim is ambiguous between two views--one plausible but unsubstantive, and one substantive but highly controversial. In answer to the second question, we argue that neither the evidence from neuroscience itself nor from other scientific and philosophical considerations supports the controversial view.

In the mammalian brain dopamine systems play a central role in the control of movement, hormone release, emotional balance and reward. Alteration of dopaminergic neurotransmission is involved in Parkinson's disease and other movement disorders, as well as in some psychotic syndromes. This review summarises recent findings, which shed some light on signals and cellular interactions involved in the specification and maturation of the dopaminergic function during neurogenesis. In particular we will focus on three major issues: (1) the differentiation of dopaminergic (...) neurones triggered by direct contact with the midbrain floor plate cells through the action of sonic hedgehog; (2) the neurotrophic factors acting on dopaminergic neurones; and (3) the role of target striatal cells on the survival and the axonal growth of developing or grafted dopaminergic neurones. (shrink)

A central issue of cognitive neuroscience is to understand how a large collection of coupled neurons combines external signals with internal memories into new coherent patterns of meaning. An external stimulus localized at some input spreads over a large assembly of coupled neurons, building up a collective state univocally corresponding to the stimulus. Thus, the synchronization of spike trains of many individual neurons is the basis of a coherent perception. Based on recent investigations of homoclinic chaotic systems and their synchronization, (...) a novel conjecture for the dynamics of single neurons and, consequently, for neuron assemblies is formulated. Homoclinic chaos is proposed as a suitable way to code information in time by trains of equal spikes occurring at apparently erratic times. In order to classify the set of different perceptions, the percept space can be given a metric structure by introducing a distance measure between distinct percepts. The distance in percept space is conjugate to the duration of the perception in the sense that an uncertainty relation in percept space is associated with time-limited perceptions. This coding of different percepts by synchronized spike trains entails fundamental quantum features which are not restricted to microscopic phenomena. It is conjectured that they are related to the details of the perceptual chain rather than depending on Planck's action. (shrink)

Gold & Stoljar argue that there are two (often confused) neuron doctrines, one trivial and the other radical, with only the latter having the consequence that non-neuroscientific sciences of the mind will be discarded. They also attempt to show that there is no evidence supporting the radical doctrine. It is argued here that their dichotomy is artificial and misrepresents modern approaches to understanding the neuroscientific correlates of cognition and behavior.

The trivial neuron doctrine (TND) holds that psychology merely depends on neurobiology. The radical neuron doctrine (RND) goes further and claims that psychology is superfluous in that neuroscience can “replace it.” Popular among RND notions of “replacement” is “reduction,” and in our commentary we challenge Gold & Stoljar (G&S) to make clear their distinction between merely depends on (TND) and is reducible to (RND). G&S give us a TND–RND distinction that is a distinction without a difference; a defensible (...) TND–RND distinction must have a metaphysical basis. We suggest a denial of compositionalism as such a basis. (shrink)

Opera is a performing art in which music plays the leading role, and the acting of singers has a synergistic effect with the music. The mirror neuron system represents the neurophysiological mechanism underlying the coupling of perception and action. Mirror neuron activity is modulated by the appropriateness of actions and clarity of intentions, as well as emotional expression and aesthetic values. Therefore, it would be reasonable to assume that an opera performance induces mirror neuron activity in the (...) audience so that the performer effectively shares an embodied performance with the audience. However, it is uncertain which aspect of opera performance induces mirror neuron activity. It is hypothesized that although auditory stimuli could induce mirror neuron activity, audiovisual perception of stage performance is the primary inducer of mirror neuron activity. To test this hypothesis, this study sought to correlate opera performance with brain activity as measured by electroencephalography in singers while watching an opera performance with sounds or while listening to an aria without visual stimulus. We detected mirror neuron activity by observing that the EEG power in the alpha frequency band was selectively decreased in the frontal-central-parietal area when watching an opera performance. In the auditory condition, however, the alpha-band power did not change relative to the resting condition. This study illustrates that the audiovisual perception of an opera performance engages the mirror neuron system in its audience. (shrink)

As presently implemented, the neuron doctrine (ND) portrays the brain's neurons and chemical synapses as fundamental components in a computer-like switching circuit, supporting a view of brain = mind = computer. However, close examination reveals individual neurons to be far more complex than simple switches, with enormous capacity for intracellular information processing (e.g., in the internal cytoskeleton). Other poorly appreciated factors (gap junctions, apparent randomness, dendritic-dendritic processing, possible quantum computation, the living state) also suggest that the ND grossly oversimplifies (...) neuronal functions. In the quest to understand consciousness, the presently implemented ND may throw out the baby with the bath water. (shrink)

Neuronal remodeling is a conserved mechanism that eliminates unwanted neurites and can include the loss of cell bodies. In these processes, a key role for glial cells in events from synaptic pruning to neuron elimination has been clearly identified in the last decades. Signals sent from dying neurons or neurites to be removed are received by appropriate glial cells. After receiving these signals, glial cells infiltrate degenerating sites and then, engulf and clear neuronal debris through phagocytic mechanisms. There are (...) few identified or proposed signals and receptors involved in neuron‐glia crosstalk, which induces the transformation of glial cells to phagocytes during neuronal remodeling in Drosophila. Many of these signaling pathways are conserved in mammals. Here, we particularly emphasize the role of Orion, a recently identified neuronal CX3C chemokine‐like secreted protein, which induces astrocyte infiltration and engulfment during mushroom body neuronal remodeling. Although, chemokine signaling was not described previously in insects we propose that chemokine‐like involvement in neuron/glial cell interaction is an evolutionarily ancient mechanism. (shrink)

We focus on the thesis that action understanding is a function of the mirror neuron system. According to our opinion, understanding is a process that runs through hermeneutic circles from the “Vorverständnis” (“previous understanding”) to steps of deeper understanding. Our critique relates to the narrow neuroscientific definition of action understanding as the capacity to recognize several movements as belonging to one action. After a reconstruction of the model's developments, we will challenge the claims of the model by Rizzolatti and (...) Sinigaglia (2010). By analyzing the relation between the experimental results and its interpretation, we will conclude that there is no proof that mirror neuron activity leads to action understanding. (shrink)

All of our information about the world is derived from the function of our senses, and thus they are the principal source of all our knowledge. This was recognized explicitly by early Greek philosophers, remained an important point of discussion for nineteenth‐century philosophers, and continues to be a key issue for present‐day philosophers, psychologists, and neuroscientists. It is a key issue in cognitive science because, by initiating the processes that store and evaluate information, sensory information transmission can be considered a (...) cognitive initiator. In a very real sense, who we are and how we see the world are the result of the experiences that are mediated by our sensory systems. These are some of the reasons why the study of sensory systems has occupied such a prominent place in modern cognitive neuroscience. (shrink)

A recent single cell mRNA sequencing study by Dueck et al. compares neuronal transcriptomes to the transcriptomes of adipocytes and cardiomyocytes. Single cell ‘omic approaches such as those used by the authors are at the leading edge of molecular and biophysical measurement. Many groups are currently employing single cell sequencing approaches to understand cellular heterogeneity in cancer and during normal development. These single cell approaches also are beginning to address long‐standing questions regarding nervous system diversity. Beyond an innate interest in (...) cataloging cell type diversity in the brain, single cell neuronal diversity has important implications for neurotypic neural circuit function and for neurological disease. Herein, we review the authors’ methods and findings, which most notably include evidence of unique expression profiles in some single neurons. (shrink)

This chapter offers a brief review of theories on mirror neuron development, highlighting different models. These models focus on either the role of genetic mechanisms or the contributions of experience and of learning processes in shaping the brain circuits involved in action–perception coupling. As an alternative, the chapter proposes an epigenetic model for mirror neuron development, explaining how such a model can help to elucidate, within a unifying explanatory framework, the emergence, diversity, and functional reuse of mirror neurons. (...) Lastly, a related evolutionary scenario is sketched in which epigenetic regulation, genetic assimilation/the Baldwin effect, and niche construction play crucial roles in mirror neuron evolution. (shrink)

Anders, Rudi They dance in view, they dance in secret. And yet they dance together...

The element of truth in behaviorism tells us that some versions of a radical neuron doctrine must be false. However, the representational nature of many mental states implies that neuroscience may well bear on some topics traditionally addressed by philosophers of mind. An example is the individuation of belief states.

Well-documented differences in the psychology and behavior of men and women have spurred extensive exploration of gender's role within the brain, particularly regarding emotional processing. While neuroanatomical studies clearly show differences between the sexes, the functional effects of these differences are less understood. Neuroimaging studies have shown inconsistent locations and magnitudes of gender differences in brain hemodynamic responses to emotion. To better understand the neurophysiology of these gender differences, we analyzed recordings of single neuron activity in the human brain (...) as subjects of both genders viewed emotional expressions. This study included recordings of single-neuron activity of 14 (6 male) epileptic patients in four brain areas: amygdala (236 neurons), hippocampus ( n = 270), anterior cingulate cortex ( n = 256), and ventromedial prefrontal cortex ( n = 174). Neural activity was recorded while participants viewed a series of avatar male faces portraying positive, negative or neutral expressions. Significant gender differences were found in the left amygdala, where 23% ( n = 15∕66) of neurons in men were significantly affected by facial emotion, vs. 8% ( n = 6∕76) of neurons in women. A Fisher's exact test comparing the two ratios found a highly significant difference between the two ( p. (shrink)

A myriad of coordinated signals control cellular differentiation. Reprogramming the cell's proteome drives global changes in cell morphology and function that define cell phenotype. A switch in alternative splicing of many pre‐mRNAs encoding neuronal‐specific proteins accompanies neuronal differentiation. Three groups recently showed that the global splicing repressor, polypyrimidine track‐binding protein (PTB), regulates this switch.1-3 Although a subset of neuronal genes are turned on in both non‐neuronal and neuronal cells, restricted expression of PTB in non‐neuronal cells diverts their mRNAs to nonsense‐mediated (...) decay and prevents protein expression. When the PTB brake is released, the cell splices like a neuron. BioEssays 30:1–4, 2008. © 2007 Wiley Periodicals, Inc. (shrink)

(1) It is not clear from Gold and Stoljar’s definition of biological neuroscience whether it includes computational and representational concepts. If so, then their evaluation of Kandel’s theory is problematic. If not, then a more direct refutation of the radical neuron doctrine is available. (2) Objections to the psychological sciences might derive not just from the conflation of the radical and the trivial neuron doctrine. There might also be the implicit belief that for many mental phenomena, adequate theories (...) must invoke neurophysiological concepts and cannot be purely psychological. (shrink)

At the global as well as local scales, some of the geometry of types of neuron arbors—both dendrites and axons—appears to be self-organizing: Their morphogenesis behaves like flowing water, that is, fluid dynamically; waterflow in branching networks in turn acts like a tree composed of cords under tension, that is, vector mechanically. Branch diameters and angles and junction sites conform significantly to this model. The result is that such neuron tree samples globally minimize their total volume—rather than, for (...) example, surface area or branch length. In addition, the arbors perform well at generating the cheapest topology interconnecting their terminals: their large-scale layouts are among the best of all such possible connecting patterns, approaching 5% of optimum. This model also applies comparably to arterial and river networks. S1063-651X 99 16205-6.. (shrink)

Neurons are arguably the most complex of all cells. From the action of these cells comes movement, thought and consciousness. It is a challenging task to understand what molecules direct the various diverse aspects of their function. This has produced an ever-increasing amount of molecular information about neurons, and only in Molecular Biology of the Neuron can a large part of this information be found in one source. In this book, a non-specialist can learn about the molecules that control (...) information flow in the brain or the progress of brain disease in an approachable format, while the expert has access to a wealth of detailed information from a wide range of topics impacting on his or her field of endeavour. The text is designed to achieve a balance of accessibility and broad coverage with up-to-date molecular detail. In the six years since the first edition of Molecular Biology of the Neuron there has been an explosion in the molecular information about neurons that has been discovered, and this information is incorporated into this second edition. Entirely new chapters have been introduced where recent advances have made a new aspect of neuronal function more comprehensible at the molecular level. Written by leading researchers in the field, the book provides an essential overview of the molecular structure and function of neurons, and will be an invaluable tool to students and researchers alike. (shrink)

G&S describe the radical neuron doctrine in a number of slightly different ways, and we think this hides an important distinction. On the one hand, the radical neuron doctrine is supposed to have the consequence "that a successful theory of the mind will make no reference to anything like the concepts of linguistics or the psychological sciences as we currently understand them", and so Chomskyan linguistics "is doomed from the beginning" (sect. 2.2.2, paras. 2,3).[1] (Note that `a successful (...) theory' must be read as `any successful theory', else the inference will fail.) On the other hand, the radical neuron doctrine is said to be the claim "that emergent psychological properties can be explained by low-level neurobiological properties" (sect. 2.3, para. 3). It is clear from the context that this can be more faithfully rendered as: psychological phenomena can be explained in (solely) neurobiological terms. But this formulation of the doctrine does not have the consequence just mentioned. (shrink)

The noncoding RNA 7SK is a critical regulator of transcription by adjusting the activity of the kinase complex P‐TEFb. Release of P‐TEFb from 7SK stimulates transcription at many genes by promoting productive elongation. Conversely, P‐TEFb sequestration by 7SK inhibits transcription. Recent studies have shown that 7SK functions are particularly important for neuron development and maintenance and it can thus be hypothesized that 7SK is at the center of many signaling pathways contributing to neuron function. 7SK activates neuronal gene (...) expression programs that are key for terminal differentiation of neurons. Proteomics studies revealed a complex protein interactome of 7SK that includes several RNA‐binding proteins. Some of these novel 7SK subcomplexes exert non‐canonical cytosolic functions in neurons by regulating axonal mRNA transport and fine‐tuning spliceosome production in response to transcription alterations. Thus, a picture emerges according to which 7SK acts as a multi‐functional RNA scaffold that is integral for neuron homeostasis. (shrink)

The concept of the receptive field, first articulated by Hartline, is central to visual neuroscience. The receptive field of a neuron encompasses the spatial and temporal properties of stimuli that activate the neuron, and, as Hubel and Wiesel conceived of it, a neuron’s receptive field is static. This makes it possible to build models of neural circuits and to build up more complex receptive fields out of simpler ones. Recent work in visual neurophysiology is providing evidence that (...) the classical receptive field is an inaccurate picture. The receptive field seems to be a dynamic feature of the neuron. In particular, the receptive field of neurons in V1 seems to be dependent on the properties of the stimulus. In this paper, we review the history of the concept of the receptive field and the problematic data. We then consider a number of possible theoretical responses to these data. (shrink)

This review article discusses Andrzej Bielecki’s book _Models of Neurons and Perceptrons: Selected Problems and Challenges_, as published by Springer International Publishing. This work exemplifies “philosophy in science” by adopting a broad, multidisciplinary perspective for the issues related to the simulation of neurons and neural networks, and the author has addressed many of the important philosophical assumptions that are entangled in this area of modeling. Bielecki also raises several important methodological issues about modeling. This book is recommended for any philosophers (...) who wish to learn more about the current state of neural modeling and find inspiration for a deeper philosophical reflection on the subject. (shrink)

activity” has been considered to play a major role in the short-term maintenance of memories. Many studies since then have provided support for this view and greatly advanced our knowledge of the effects of stimulus type and modality on delay activity and its temporal dynamics. In humans, working memory has also been a subject of intense investigation using scalp and intracranial electroencephalography as well as magnetoencephalography, which provide estimates of local population activity. The published findings include reports of systematic changes (...) in signal amplitude during working memory in the theta, alpha, beta. (shrink)

Phantom limb experiences demonstrate an unexpected degree of fragility inherent in our self-perceptions. This is perhaps most extreme when congenitally absent limbs are experienced as phantoms. Aplasic phantoms highlight fundamental questions about the physiological bases of self-experience and the ontogeny of a physical, embodied sense of the self. Some of the most intriguing of these questions concern the role of mirror neurons in supporting the development of self–other mappings and hence the emergence of phantom experiences of congenitally absent limbs. In (...) this paper, we will examine the hypothesis that aplasic phantom limb experience is the result of an ontogenetic interplay between body schemas and mirror neuron activity and that this interplay is founded on embedding in a social context. Phantom limb experience has been associated with the persistence of subjective experience of a part of the body after deafferentation through surgical or traumatic removal. We maintain that limited association is inconsistent with the extent to which phantom limb experience is reported by aplasic individuals. (shrink)