The mature cerebral cortex contains a staggering variety of projection neuron subtypes, and a number of complementary studies have recently begun to define their identity and embryonic origin. Among the different types of cortical projection neurons, subcerebral projection neurons, including corticospinal motor neurons (CSMN), have been extensively studied and some of the molecular controls over their differentiation have been elucidated. Here, we first provide an overview of the approaches used to purify and molecularly (...) profile neuronal populations of the neocortex and, more broadly, of the central nervous system (CNS). Next, we specifically review recent progress in understanding the genes that define and control development of the CSMN population. Finally, we briefly discuss the relevance of this work to current questions regarding the mechanisms of the establishment of projection neuron subtype identity in the neocortex and its implications to direct the differentiation of CSMN for therapeutic benefit. (shrink)

Previous studies examining EEG and LORETA in patients with chronic pain discovered an overactivation of high theta and low beta power in central regions. MEG studies with healthy subjects correlating evoked nociception ratings and source localization described delta and gamma changes according to two music interventions. Using similar music conditions with chronic pain patients, we examined EEG in response to two different music interventions for pain. To study this process in-depth we conducted a mixed-methods case study approach, based on three (...) clinical cases. Effectiveness of personalized music therapy improvisations versus preferred music on chronic pain was examined with 16 participants. Three patients were randomly selected for follow-up EEG sessions three months post-intervention, where they listened to recordings of the music from the interventions provided during the research. To test the difference of EM versus preferred music, recordings were presented in a block design: silence, their own composed EM, preferred music, and a non-participant’s EM as a control. Participants rated their pain before and after the EEG on a 1–10 scale. We conducted a detailed single case analysis to compare all conditions, as well as a group comparison of entrainment-healing condition versus preferred music condition. Power spectrum and according LORETA distributions focused on expected changes in delta, theta, beta, and gamma frequencies, particularly in sensory-motor and central regions. Intentional moment-by-moment attention on the sounds/music rather than on pain and decreased awareness of pain was experienced from one participant. Corresponding EEG analysis showed accompanying power changes in sensory-motor regions and LORETA projection pointed to insula-related changes during entrainment-pain music. LORETA also indicated involvement of visual-spatial, motor, and language/music improvisation processing in response to his personalized EM which may reflect active recollection of creating the EM. Group-wide analysis showed common brain responses to personalized entrainment-healing music in theta and low beta range in right pre- and post-central gyrus. We observed somatosensory changes consistent with processing pain during entrainment-healing music that were not seen during preferred music. These results may depict top–down neural processes associated with active coping for pain. (shrink)

It has been shown that visual awareness in the blind hemifield of hemianopic cats that have undergone unilateral ablations of visual cortex can be restored by sectioning the commissure of the superior colliculus or by destroying a portion of the substantia nigra contralateral to the cortical lesion (the Sprague effect). We propose that the visual awareness that is recovered is due to synchronized oscillatory activities in the superior colliculus ipsilateral to the cortical lesion. These oscillatory activities are normally partially suppressed (...) by the inhibitory, GABAergic contralateral nigrotectal projection, and the destruction of the substantia nigra, or the sectioning of the collicular commissure, disinhibits the collicular neurons, causing an increase in the extent of oscillatory activity and/or synchronization between activities at different sites. This increase in the oscillatory and synchronized character is sufficient for the activities to give rise to visual awareness. We argue that in rodents and lower vertebrates, normal visual awareness is partly due to synchronized oscillatory activities in the optic tectum and partly due to similar activities in visual cortex. It is only in carnivores and primates that visual awareness is wholly due to cortical activities. Based on von Baerian recapitulation theory, we propose that, even in humans, there is a period in early infancy when visual awareness is partially due to activities in the superior colliculus, but that this awareness gradually disappears as the nigrotectal projection matures. (shrink)

Summary Ideomotor apraxia is a cognitive disorder in which the patient loses the ability to accurately perform learned, skilled actions. This is despite normal limb power and coordination. It has long been known that left supramarginal gyrus lesions cause bilateral upper limb apraxia and it was proposed that this area stored a visualkinaesthetic image of the skilled action, which was translated elsewhere in the brain into the pre-requisite movement formula. We hypothesise that, rather than these two functions occurring separately, both (...) are complementary functions of chains of ‘‘mirror neurons’’ within the left inferior parietal lobe. We go on to propose that this neural mechanism in the supramarginal gyrus and its projection zones, which originally evolved to allow the creation of a direct map between vision and movement, was subsequently exapted to allow other sorts of cross-domain mapping and in particular those sorts of abstract re-conceptualisation, such as metaphor, that make mankind unique. (shrink)

Our understanding of neuronal migration has been advanced by multidisciplinary approaches. At the cellular level, tangential and radial modes of neuronal migration contribute to different populations of neurons and have differential dependence on glial cells. At the molecular level, extracellular guidance cues have been identified and intracellular signal transduction pathways are beginning to be revealed. Interestingly, mechanisms guiding axon projection and neuronal migration appear to be conserved with those for chemotactic leukocytes. BioEssays 24:821–827, 2002. © 2002 Wiley Periodicals, (...) Inc. (shrink)

Open peer commentary on the target article “Who Conceives of Society?” by Ernst von Glasersfeld. First paragraph: Cognitive psychology, neurobiology, and cognitive systems research provide diverse clues as to how we are able to incrementally construct representations of the perceived environment and how we consequently understand other individuals and society. The construction of an individual’s reality starts with the capability to control one’s own body and to be able to predict the usual sensory effects caused by body movements. To be (...) able to infer the potential intentions of others, mirror neurons project one’s own behavioral codes onto perceived patterns that are caused by others. Equipped with representations of many other individuals, personal social realities are constructed. In this commentary, I focus on these points for the construction of social reality and the consequent existence of society as a whole. (shrink)

First of all, we would like to gratefully thank all commentators for the attention and effort they have put into reading and responding to our review paper [this issue] and for useful observations that suggest novel applications for our framework. We understand and accept that some of our claims might appear controversial and raise skepticism, because the overall neural framework we have proposed is difficult to frame in established categories, given its strong multidisciplinary character. To make an example, Elsevier is (...) publishing the British Neuroscience Association (BNA) 2017 Special Issue Collection. However, our paper could not fully fit in any of their Special Issues—attention, motivation, behavior; sensory and motor systems; novel treatments and translational neuroscience; genetics and epigenetics; learning and memory; neurodegenerative disorders and ageing; developmental neuroscience; neuronal, glial and cellular mechanisms; neuroendocrine and autonomic nervous systems; psychiatry and mental health; methods and techniques. Perhaps because our paper was mathematically, physically, biologically (neuroscientifically), and phenomenologically motivated from the start? Nevertheless, venturing in novel, fresh, testable proposals is badly needed in contemporary neuroscience, so to break into “the utter darkness of the inner mechanism of psychic acts… during the production of the concomitant phenomena of perception and thought, namely, feelings, consciousness and volition”—as Cajal had already observed in his opus magnus ‘Textura’. But as he soberly confessed: “This ideal is still very distant” (Ramon y Cajal, 1899-1904, p. 1,141). In the pursuit of that very ideal, neuroscience and psychology have had, and continue to have, a plethora of movements and schools of thought: behaviorism, cognitivism, neural Darwinism, social constructivism, Bayesian optimization...In our paper, we propose to go a step further, via the notion of topodynamics, towards “projectionism.” In what follows, trying to elucidate the main features of this Emperor’s new clothing, we proceed with the responses to the comments received. (shrink)

Neurofilaments and microtubules are important components of the neuronal cytoskeleton. In axons or dendrites, these filaments are aligned in parallel arrays, and separated from one another by nonrandom distances. This distinctive organization has been attributed to cross bridges formed by NF side arms or microtubule‐associated proteins. We recently proposed a polymer‐brush‐based mechanism for regulating interactions between neurofilaments and between microtubules. In this model, the side arms of neurofilaments and the projection domains of microtubule‐associated proteins are highly unstructured and exert (...) long‐range repulsive forces that are largely entropic in origin; these forces then act to organize the cytoskeleton in axons and dendrites. Here, we review the biochemical, biophysical, genetic and cell biological data for the polymer‐brush and cross‐bridging models. We explore how the data traditionally used to support cross bridging may be reconciled with a polymer‐brush mechanism and compare the implications of recent experimental insights into axonal transport and physiology for each model. BioEssays 26:1017–1025, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:A Still Life Is Really a Moving LifeThe Role of Mirror Neurons and Empathy in Animating Aesthetic ResponseCarol S. Jeffers (bio)IntroductionIn the Western aesthetic canon, the still life enjoys a certain prestige; its place in the museum and on the pages of the art history text is secure. Art aficionados who appreciate the character of Cezanne's apples help to ensure the lofty standing of the still life, as (...) do students who admire the dewdrops still glistening on flowers picked and painted in the nineteenth century. For some students, however, it is difficult to understand such veneration. Despite the coaxing of dedicated art or museum educators, these students find apples nestled among drapery folds or translucent petals in a spring bouquet to be "boring." No matter how compelling the apples, how exquisitely rendered the blossoms, the still life is much too static, offering little more than the lifelessness of inanimate objects.In my experience, even the most unappreciative of students can be persuaded to take a closer look at the inanimate—not by me or any strategies I may have devised but rather by classmates who have chosen still life paintings to serve as their personal metaphors. When shared during the courses I teach, these still lifes and their depicted objects acquire special meanings that are uniquely associated with the individual students who chose them. Reflecting on these class presentations, converted students offered these thoughts: "I related myself with the metaphors and the way my classmates felt"; and "What really stayed with me were the stories and the way my classmates connected with their paintings—how they connected to the art emotionally." Still another wrote: "I really liked the way their presentations went because I got to know [my classmates] a little bit more." Through these connections to still life and other genres, students explored [End Page 31] their concepts of self within a community of others and began to experience the power of empathy.Empathy, typically defined as "the intellectual or emotional identification with another,"1 is a human capacity that, according to the noted neuroscientist Vittorio Gallese, allows us to understand the world of objects as well as the world of others.2 With the recent discovery of the mirror neuron system in the human brain, Gallese and other investigators around the world have identified the neurological basis of empathy.3 Subsequent studies of the remarkable properties of mirror neurons have yielded potent new understandings of the connections between empathy, objects of art and material culture, and intrapersonal relationships among human beings. Interestingly, these twenty-first-century findings tend to confirm a nineteenth-century connection between aesthetics and empathy, or more precisely, Einfuhlung ("in-feeling," or "feeling into"), a term coined by the philosopher Robert Vischer in 1873 to describe the projection of human feeling onto art objects.4 As Vischer himself described this phenomenon, "I transport myself into the inner being of an object and explore its formal character from within, as it were."5These insights, whether gained through the use of state-of-the-art brain imaging technologies or dusty volumes in a German library, have led Gallese to consider some interesting implications, such as, for example, those involving the still life—its bottles, apples, even its brushstrokes—and to claim that "a still life is really a moving life" when understood from the perspective of neuroscience.6 To explore this claim and its relevance to classroom and museum practices, this article examines the relationship between mirror neurons, empathy, and aesthetic response as it developed among preservice teachers who presented metaphorical works of art in two teacher education courses. A brief synopsis of research results highlighting the workings of the mirroring mechanism is presented and then applied to two student presentations: one given by Molly about Cezanne's Still Life with Apples (1893-94) and the other by Deborah about Fantin-Latour's White and Pink Mallows in a Vase (1895). The stories told by Molly, Deborah, and their classmates allow additional insights with implications for art and museum education.Mirror Neurons: Some Research ResultsSome fifteen years ago, what Gallese characterizes as a "strange class" of neurons was discovered, first... (shrink)

From single‐cell organisms to complex neural networks, all evolved to provide control solutions to generate context‐ and goal‐specific actions. Neural circuits performing sensorimotor computation to drive navigation employ inhibitory control as a gating mechanism as they hierarchically transform (multi)sensory information into motor actions. Here, the focus is on this literature to critically discuss the proposition that prominent inhibitory projections form sensorimotor circuits. After reviewing the neural circuits of navigation across various invertebrate species, it is argued that with increased neural circuit (...) complexity and the emergence of parallel computations, inhibitory circuits acquire new functions. The contribution of inhibitory neurotransmission for navigation goes beyond shaping the communication that drives motor neurons, and instead includes encoding of emergent sensorimotor representations. A mechanistic understanding of the neural circuits performing sensorimotor computations in invertebrates will unravel the minimum circuit requirements driving adaptive navigation. (shrink)

All complex systems are complex, but some are more complex than others are. Biological systems are generally more complex than physical systems. How do biologists tackle complex systems? In this talk, we will consider two biological systems, the genome and the brain. Scientists know much about them, but much more remains unknown. Ignorance breeds philosophical speculation. Reductionism makes a strong showing here, as it does in other frontier sciences where large gaps remain in our understanding. I will show that reductionism (...) and its claims have no bases in actual scientific research and results. The Human Genome Project will serve as a case in point.. (shrink)

Heterotrimeric G proteins, consisting of α, β, and γ subunits, couple ligand-bound seven transmembrane domain receptors to the regulation of effector proteins and production of intracellular second messengers. G protein signaling mediates the perception of environmental cues in all higher eukaryotic organisms, including yeast, Dictyostelium, plants, and animals. The nematode Caenorhabditis elegans is the first animal to have complete descriptions of its cellular anatomy, cell lineage, neuronal wiring diagram, and genomic sequence. In a recent paper, Jansen et al.(1) used sequence (...) searches of the C. elegans genome database to identify all heterotrimeric G protein genes (20 Gα, 2 Gβ, 2 Gγ). C. elegans encodes one ortholog of each of the four Gα classes found in metazoans and 16 new Gα genes. The orthologous genes are widely expressed, whereas 14 of the divergent Gα genes are almost exclusively expressed in sensory neurons where they may regulate perception and chemotaxis.BioEssays 21:713–717, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

Heterotrimeric G proteins, consisting of α, β, and γ subunits, couple ligand-bound seven transmembrane domain receptors to the regulation of effector proteins and production of intracellular second messengers. G protein signaling mediates the perception of environmental cues in all higher eukaryotic organisms, including yeast, Dictyostelium, plants, and animals. The nematode Caenorhabditis elegans is the first animal to have complete descriptions of its cellular anatomy, cell lineage, neuronal wiring diagram, and genomic sequence. In a recent paper, Jansen et al.(1) used sequence (...) searches of the C. elegans genome database to identify all heterotrimeric G protein genes (20 Gα, 2 Gβ, 2 Gγ). C. elegans encodes one ortholog of each of the four Gα classes found in metazoans and 16 new Gα genes. The orthologous genes are widely expressed, whereas 14 of the divergent Gα genes are almost exclusively expressed in sensory neurons where they may regulate perception and chemotaxis.BioEssays 21:713–717, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

Praise for Volume 1: "... a first-rate edition, which supersedes all other portable Peirces.... all the Peirce most people will ever need." —Louis Menand, The New York Review of Books Volume 2 of this convenient two-volume chronological reader’s edition provides the first comprehensive anthology of the brilliant American thinker Charles Sanders Peirce’s mature philosophy. A central focus of Volume 2 is Peirce’s evolving theory of signs and its appplication to his pragmatism.

The Bentham Project is delighted to announce a call for papers for “Bentham and Australia: Convicts, Utility, and Empire”, a conference to be held at University College London on 11-12 April 2019 to mark the forthcoming publication of Writings on Australia, a volume of The Collected Works of Jeremy Bentham. The conference will explore themes such as the influence and impact of Bentham’s ideas on the theory and practice of punishment in convict Australia, on advocates and opponents of co...

Volume 8 of this landmark edition follows Peirce from May 1890 through July 1892—a period of turmoil as his career unraveled at the U.S. Coast and Geodetic Survey. The loss of his principal source of income meant the beginning of permanent penury and a lifelong struggle to find gainful employment. His key achievement during these years is his celebrated Monist metaphysical project, which consists of five classic articles on evolutionary cosmology. Also included are reviews and essays from The Nation in (...) which Peirce critiques Paul Carus, William James, Auguste Comte, Cesare Lombroso, and Karl Pearson, and takes part in a famous dispute between Francis E. Abbot and Josiah Royce. Peirce's short philosophical essays, studies in non-Euclidean geometry and number theory, and his only known experiment in prose fiction complete his production during these years. Peirce's 1883-1909 contributions to the Century Dictionary form the content of volume 7 which is forthcoming. (shrink)

Praise for Volume 1: "... a first-rate edition, which supersedes all other portable Peirces.... all the Peirce most people will ever need." —Louis Menand, The New York Review of Books Volume 2 of this convenient two-volume chronological reader’s edition provides the first comprehensive anthology of the brilliant American thinker Charles Sanders Peirce’s mature philosophy. A central focus of Volume 2 is Peirce’s evolving theory of signs and its appplication to his pragmatism.

Abstract“Sign stimuli” elicit specific patterns of behavior when an organism's motivation is appropriate. In the toad, visually released prey-catching involves orienting toward the prey, approaching, fixating, and snapping. For these action patterns to be selected and released, the prey must be recognized and localized in space. Toads discriminate prey from nonprey by certain spatiotemporal stimulus features. The stimulus-response relations are mediated by innate releasing mechanisms (RMs) with recognition properties partly modifiable by experience. Striato-pretecto-tectal connectivity determines the RM's recognition and localization (...) properties, whereas medialpallio-thalamo-tectal circuitry makes the system sensitive to changes in internal state and to prior history of exposure to stimuli. RMs encode the diverse stimulus conditions referring to the same prey object through different combinations of “specialized” tectal neurons, involving cells selectively tuned to prey features. The prey-selective neurons express the outcome of information processing in functional units consisting of interconnected cells. Excitatory and inhibitory interactions among feature-sensitive tectal and pretectal neurons specify the perceptual operations involved in distinguishing the prey from its background, selecting its features, and discriminating it from predators. Other connections indicate stimulus location. The results of these analyses are transmitted by specialized neurons projecting from the tectum to bulbar/spinal motor systems, providing a sensorimotor interface. Specific combinations of such projective neurons – mediating feature- and space-related messages – form “command releasing systems” that activate corresponding motor pattern generators for appropriate prey-catching action patterns. (shrink)

The discovery of so-called ‘mirror neurons’ - found to respond both to own actions and the observation of similar actions performed by others - has been enormously influential in the cognitive sciences and beyond. Given the self-other symmetry these neurons have been hypothesized as underlying a ‘mirror mechanism’ that lets us share representations and thereby ground core social cognitive functions from intention understanding to linguistic abilities and empathy. I argue that mirror neurons are important for very different (...) reasons. Rather than a symmetric ubiquitous or context- independent mechanism, I propose that these neurons are part of broader sensorimotor circuits, which help us navigate and predict the social affordance space that we meet others in. To develop both the critical and positive project I analyze the interpretive choices and the debate surrounding the mirror neuron research and show how the field is marred by highly questionable assumptions about respectively motor and social cognition. The discovery of mirror neurons - and the sensorimotor circuits of which these neurons are a part – actually empirically challenge many of these tacit assumptions. Findings of sensorimotor goal representations at levels of abstraction well beyond actual sensory information and kinetic movements challenge the idea of motor cognition as primarily output production. Additionally, the focus on 3rd person mindreading of hidden mental states is misguiding the field of social cognition. Much ‘mind-reading’ seems rooted in sensorimotor representations and a developmentally primary 2nd person understanding of actions and the mental lives of others, which precisely breaks the assumed dichotomy between mind and behavior. I propose a Social Affordance model where parallel fronto-parietal sensorimotor circuits support representations not just of other people’s actions but of the overall social affordance space. It is a process that monitors concrete goals and teleological possibilities that the environment affords respectively oneself and other present agents. With this model I hypothesize that the complex spectrum of sensorimotor integrations are indeed essential not only to normal action choice calibration but also to social cognitive abilities, as the sensorimotor teleological representations let us relate to others and understand their action choices in a shared pragmatic and intentional context. (shrink)

Shaun Gallagher and Dan Zahavi have recently argued against a simulationist interpretation of neural resonance. Recognizing intentions and emotions in the facial expressions and gestures of others may be subserved by e.g. mirror neuron activity, but this does not mean that we first experience an intention or emotion and then project it onto the other. Mirror neurons subserve social cognition, according to Gallagher and Zahavi, by being integral parts of processes of enactive social perception. I argue that the notion (...) of enactive social perception does not yet explain why social perception is subserved by mirroring. I also argue that this problem cannot be avoided by means of an appeal to multiple realization. Instead, I propose a holistic model of neural resonance-based social cognition that does give an explanatory role to mirroring by allowing for a partial experiential overlap between experiencing and recognizing emotions and intentions. This account avoids the simulationist step-wise conception of social cognition and recognizes the qualitative difference between first- and third-person emotion and intention attribution. It does capture too much of the simulationist intuitions, however, to warrant the label ‘social perception’. (shrink)

Neuronal aggregates involved in conscious awareness are not evenly distributed throughout the CNS but comprise key components referred to as the neural network correlates of consciousness (NNCC). A critical node in this network is the posterior cingulate, precuneal, and retrosplenial cortices. The cytological and neurochemical composition of this region is reviewed in relation to the Brodmann map. This region has the highest level of cortical glucose metabolism and cytochrome c oxidase activity. Monkey studies suggest that the anterior thalamic projection (...) likely drives retrosplenial and posterior cingulate cortex metabolism and that the midbrain projection to the anteroventral thalamic nucleus is a key coupling site between the brainstem system for arousal and cortical systems for cognitive processing and awareness. The pivotal role of the posterior cingulate, precuneal, and retrosplenial cortices in consciousness is demonstrated with posterior cingulate epilepsy cases, midcingulate lesions that de-afferent this region and are associated with unilateral sensory neglect, observations from stroke and vegetative state patients, alterations in blood flow during sleep, and the actions of general anesthetics. Since this region is critically involved in self reflection, it is not surprising that it is similarly a site for the NNCC. Interestingly, information processing during complex cognitive tasks and during aversive sensations such as pain induces efforts to terminate self reflection and result in decreased processing in posterior cingulate and precuneal cortices. (shrink)

Barbara Stafford is at the forefront of a growing movement that calls for the humanities to confront the brain’s material realities. In Echo Objects she argues that humanists should seize upon the exciting neuroscientific discoveries that are illuminating the underpinnings of cultural objects. In turn, she contends, brain scientists could enrich their investigations of mental activity by incorporating phenomenological considerations—particularly the intricate ways that images focus intentional behavior and allow us to feel thought. This, then, is a book for both (...) sides of the aisle, a stunningly broad exploration of how complex images—or patterns that compress space and time—make visible the invisible ordering of human consciousness. Stafford demonstrates, for example, how the compound formats of emblems, symbols, collage, and electronic media reveal the brain’s grappling to construct mental objects that are redoubled by prior associations. On the other hand, she compellingly shows that findings in evolutionary biology and the neurosciences are providing profound opportunities for understanding aesthetic conundrums as old and deep-seated as the human urge to imitate, the mapping of inner space, and the role of narrative and nonnarrative representation. As precise in her discussions of firing neurons as she is about the coordinating dynamics of image making, Stafford locates these major transdisciplinary issues at the intersection of art, science, philosophy, and technology. Ultimately, she makes an impassioned plea for a common purpose—for the acknowledgement that, at the most basic level, these separate projects belong to a single investigation. (shrink)

Practice Then and Now "Practice theory" has a long history in philosophy, under various names, but current practice theory is a response to failures of projects of modernity or enlightenment which attempt to reduce science or politics to formulae. Heidegger, Oakeshott, and MacIntyre are each examples of philosophers who turned to practice conceptions. Foucault and Bourdieu made similar turns. Practice accounts come in different forms: some emphasize skill-like individual accomplishments, others emphasize the social character or presupposition-like character of the tacit (...) conditions of activities. The Social Theory of Practices problematized the idea of sameness, the idea that participants in an activity had the same tacit possessions, which undermined the idea that practices were collective objects in which individuals participated. Later critics, such as Schatzki and Rouse, emphasized the normative coherence and character of practice, which has a collective aspect. Pickering and others suggested a notion of practices that was de-mentalized and focused on the objects that were part of the practical activity, which provided for the continuity and sociality of practice without collectivizing its mental content. The discovery of mirror neurons suggested a non-collective mode of transmission of practices. The implications of these developments can be seen in connection with ethics, where the conflict between the ethical and the practical can be understood in terms of the intrinsic conflict between the need to behave successfully and our learned ethical intuitions. (shrink)

Recent studies on neural pathways in a broad spectrum of vertebrates suggest that, in addition to migration and an increase in the number of certain select neurons, a significant aspect of neural evolution is a “parcellation” (segregation-isolation) process that involves the loss of selected connections by the new aggregates. A similar process occurs during ontogenetic development. These findings suggest that in many neuronal systems axons do not invade unknown territories during evolutionary or ontogenetic development but follow in their ancestors' (...) paths to their ancestral targets; if the connection is later lost, it reflects the specialization of the circuitry.The pattern of interspecific variability suggests (1) that overlap of circuits is a more common feature in primitive (generalized) than in specialized brain organizations and (2) that most projections, such as the retinal, thalamotelencephalic, corticotectal, and tectal efferent ones, were bilateral in the primitive condition. Specialization of these systems in some vertebrate groups has involved the selective loss of connections, resulting in greater isolation of functions. The parcellation process may also play an important role in cell diversification.The parcellation process as described here is thought to be one of several underlying mechanisms of evolutionary and ontogenetic differentiation. (shrink)

The highly ordered neuronal projections from the retina to the tectum mesencephali (optic tectum) in several vertebrate groups have been intensively studied. Several hypotheses so far have been proposed, suggesting mechanisms to explain the topographical and biochemical specificity of the retinotectal projections during ontogeny. In the present paper we compare the main hypotheses of retinotectal development with respect to the nature of specificity envisaged, the activity-dependence versus inheritance criterium and the strategy of argument, in casu the descriptive versus interferential type (...) of argument. Matching of the current developmental hypotheses and mechanisms for elimination or persistance of contralateral, respectively ipsilateral connections, is attempted with respect to the known neuroanatomical connectivity data in the amphibian optic tectum and with respect to the symmetry relations between ipsilateral and contralateral connection patterns described in amphibians and other vertebrate groups. Local mechanisms influencing the survival potential of synaptic contacts between retinal afferents and tectal neurons are probably essential for generating global symmetry patterns. Finally, a global topological approach is discussed with respect to its applicability in the amphibian retinotectal projection system. Basic assumptions of topological modeling appear to rely on anatomical and functional properties of the visual system like left-right symmetry, dichotomy, (absence of) convergence and segregation of fibers and neurons into columnar information units. It is concluded however, that more neuroanatomical, physiological and ultrastructural data are needed to establish a formalized operation model of the amphibian retinotectal system. (shrink)

The influential Italian thinker offers three essays in the political philosophy of language. Multitude between Innovation and Negation by Paolo Virno translated by James Cascaito. The publication of Paolo Virno's first book in English, Grammar of the Multitude, by Semiotext in 2004 was an event within the field of radical political thought and introduced post-'68 currents in Italy to American readers. Multitude between Innovation and Negation, written several years later, offers three essays that take the reader on a journey through (...) the political philosophy of language. “Wit and Innovative Action” explores the ambivalence inevitably arising when the semiotic and the semantic, grammar and experience, rule and regularity, and right and fact intersect. Virno unravels the infinite potential and wonders of everyday linguistic praxis and ambiguity. Wit, he argues, is a public performance, and its modus operandi characterizes human action in a state of emergency; it is a reaction, an articulate response, and a possible solution to a state of crisis. “Mirror Neurons, Linguistic Negation, and Mutual Recognition” examines the relationship of language and intersubjective empathy: without language, would human beings be able to recognize other members of their species? And finally, in “Multitude and Evil,” Virno challenges the distinction between the state of nature and civil society and argues for a political institution that resembles language in its ability to be at once nature and history. Few thinkers take the risks required by innovation. Like a philosophical entrepreneur, Virno is engaged in no less than rewriting the dictionary of political theory, an urgent and ambitious project when language, caught in a permanent state of emergency impossible to sustain, desperately needs to articulate and enact new practices of freedom for the multitude. Paolo Virno is the author of several books, including A Grammar of the Multitude, 2004). (shrink)

Cognitive deficits were produced in rats by different methods of damaging the brain: chronic ingestion of alcohol, causing widespread damage to diffuse cholinergic and aminergic projection systems; lesions (by local injection of the excitotoxins, ibotenate, quisqualate, and AMPA) of the nuclei of origin of the forebrain cholinergic projection system (FCPS), which innervates the neocortex and hippocampal formation; transient cerebral ischaemia, producing focal damage especially in the CA1 pyramidal cells of the dorsal hippocampus; and lesions (by local injection of (...) the neurotoxin, colchicine) of the granule cells of the dentate gyrus. Following chronic alcohol or lesions of the FCPS, transplants of cholinergically rich fetal brain tissue into the terminal areas (neocortex and/or hippocampus) restored performance almost to control levels, with a time course consistent with growth of the transplants and integration with host tissue; transplants of cholinergically poor fetal tissue (hippocampus) were without effect, as were transplants of cholinergically rich tissue into the region containing the nuclei of origin of the FCPS. Grafts of primary cells enriched in glia and cultured neuroblastoma cells into the terminal areas of the FCPS were equally effective, suggesting that there are multiple mechanisms by which neural transplants can restore cognitive function following diffuse cholinergic damage. In contrast, after ischaemia- or neurotoxin-induced damage to CA1 or dentate granule cells respectively, cholinergically rich fetal transplants into the damaged hippocampal formation were ineffective in restoring performance. After ischaemic damage, however, performance was restored by suspension grafts of CA1 cells but not by transplants containing CA3 pyramidal cells or granule cells; and after colchicine damage it was restored by solid grafts containing granule but not CA1 pyramidal cells. Furthermore, electrophysiological evidence has demonstrated functional, graft type-specific host-graft functional neuronal connectivity. Thus, restoration of cognitive function by neural transplants is possible after damage to either diffuse (cholinergic) or point-to-point (intrahippocampal) forebrain systems, but the transplant must be appropriate to the damage to be repaired. Because the different types of brain damage studied provide analogues of human alcoholic dementia, Alzheimer's disease, and heart attack, these results are encouraging with regard to the eventual application of neural transplant surgery to the treatment of cognitive deficits in humans. (shrink)

In this collection of essays Samuel Wheeler discusses Derrida and other “deconstructive” thinkers from the perspective of an analytic philosopher willing to treat deconstruction as philosophy, taking it seriously enough to look for and analyze its arguments. The essays focus on the theory of meaning, truth, interpretation, metaphor, and the relationship of language to the world. Wheeler links the thought of Derrida to that of Davidson and argues for close affinities among Derrida, Quine, de Man, and Wittgenstein. He also demonstrates (...) the propinquity of Plato and Derrida and shows that New Criticism shares deconstruction’s conception of language. Of the twelve essays in the collection, four are published here for the first time. The fundamental resemblance between Derrida and such analytic thinkers as Quine, Wittgenstein, and Davidson, the author argues, is that they deny the possibility of meanings as self-interpreting media constituting thoughts and intentions. Derrida argues that some form of magic language has determined the very project of philosophy, and his arguments work out the consequences of denying that there are such self-interpreting mental contents. In addition, Derrida and Davidson agree in denying any “given.” Without a given, questions about realism and idealism cease to have a point. Derrida and Davidson are both committed to the textuality of all significant marks, whether in neurons or on paper. They argue that there is no mode of representation more direct than language. (shrink)

_A surprising, sweeping, and deeply researched history of empathy—from late-nineteenth-century German aesthetics to mirror neurons_ _Empathy: A History_ tells the fascinating and largely unknown story of the first appearance of “empathy” in 1908 and tracks its shifting meanings over the following century. Despite empathy’s ubiquity today, few realize that it began as a translation of _Einfühlung _or “in-feeling” in German psychological aesthetics that described how spectators projected their own feelings and movements into objects of art and nature. Remarkably, this early (...) conception of empathy transformed into its opposite over the ensuing decades. Social scientists and clinical psychologists refashioned empathy to require the deliberate putting aside of one’s feelings to more accurately understand another’s. By the end of World War II, interpersonal empathy entered the mainstream, appearing in advice columns, popular radio and TV, and later in public forums on civil rights. Even as neuroscientists continue to map the brain correlates of empathy, its many dimensions still elude strict scientific description. This meticulously researched book uncovers empathy’s historical layers, offering a rich portrait of the tension between the reach of one’s own imagination and the realities of others’ experiences. (shrink)

Barbara Maria Stafford is at the forefront of a growing movement that calls for the humanities to confront the brain’s material realities. In _Echo Objects,_ she argues that humanists should seize upon the exciting neuroscientific discoveries that are illuminating the underpinnings of cultural objects. In turn, she contends, brain scientists could enrich their investigations of mental activity by incorporating phenomenological considerations—particularly the intricate ways that images focus intentional behavior and allow us to feel thought. As a result, _Echo Objects_ is (...) a stunningly broad exploration of how complex images—or patterns that compress space and time—make visible the invisible ordering of human consciousness. Stafford demonstrates, for example, how the compound formats of emblems, symbols, collage, and electronic media reveal the brain’s grappling to construct mental objects that are redoubled by prior associations. In contrast, she shows that findings in evolutionary biology and the neurosciences are providing profound opportunities for understanding aesthetic conundrums such as the human urge to imitate and the role of narrative and nonnarrative representation. Ultimately, she makes an impassioned plea for a common purpose—for the acknowledgement that, at the most basic level, these separate projects belong to a single investigation. “Heroic.... The larger message of Stafford’s intense, propulsive prose is unassailable. If we are to get much further in the great puzzle of ‘binding’—how the perception of an image, the will to act on intention, or the forging of consciousness is assembled from the tens of thousands of neurons firing at any one moment in time—then there needs to be action on all fronts.”—_Science_. (shrink)

Resumen En el marco de la filosofía de la mente, este artículo aborda el problema de la causación mental en el proyecto naturalista biológico de John Searle. A partir de la concepción de la mente como un fenómeno emergente de procesos cerebrales, evalúo las críticas que Jaegwon Kim realiza a la eficacia causal de la consciencia, centrándome en los argumentos de sobredeterminación y violación del principio de clausura físico causal. Luego analizo el debate de la causación mental a partir de (...) los descubrimientos de Benjamin Libet respecto a la existencia de actividad neuronal pre-consciente en la conducta motora voluntaria. Dicha actividad, llamada potencial de preparación, junto a la noción de causación trabajada en neurociencia, avala la eficacia causal de los estados mentales, pero en un sentido distinto al propuesto por Searle.Within the framework of philosophy of mind, this paper addresses the problem of mental causation in John Searle's biological naturalist project. Beginning with the conception of the mind as a phenomenon emerging from cerebral processes, I evaluate the criticisms that Jaegwon Kim makes to the causal efficacy of consciousness, focusing on the arguments of overdetermination and violation of the principle of physical causal closure. Then, I analyze the debate on mental causation from the findings of Benjamin Libet regarding the existence of pre-conscious neural activity in voluntary motor behavior. This activity, called readiness potential, and the notion of causation worked in neuroscience, support the causal efficacy of mental states, but in a different sense from that proposed by Searle. (shrink)

Resumen En el marco de la filosofía de la mente, este artículo aborda el problema de la causación mental en el proyecto naturalista biológico de John Searle. A partir de la concepción de la mente como un fenómeno emergente de procesos cerebrales, evalúo las críticas que Jaegwon Kim realiza a la eficacia causal de la consciencia, centrándome en los argumentos de sobredeterminación y violación del principio de clausura físico causal. Luego analizo el debate de la causación mental a partir de (...) los descubrimientos de Benjamin Libet respecto a la existencia de actividad neuronal pre-consciente en la conducta motora voluntaria. Dicha actividad, llamada potencial de preparación, junto a la noción de causación trabajada en neurociencia, avala la eficacia causal de los estados mentales, pero en un sentido distinto al propuesto por Searle.Within the framework of philosophy of mind, this paper addresses the problem of mental causation in John Searle's biological naturalist project. Beginning with the conception of the mind as a phenomenon emerging from cerebral processes, I evaluate the criticisms that Jaegwon Kim makes to the causal efficacy of consciousness, focusing on the arguments of overdetermination and violation of the principle of physical causal closure. Then, I analyze the debate on mental causation from the findings of Benjamin Libet regarding the existence of pre-conscious neural activity in voluntary motor behavior. This activity, called readiness potential, and the notion of causation worked in neuroscience, support the causal efficacy of mental states, but in a different sense from that proposed by Searle. (shrink)

It is not widely realised that Turing was probably the first person to consider building computing machines out of simple, neuron-like elements connected together into networks in a largely random manner. Turing called his networks 'unorganised machines'. By the application of what he described as 'appropriate interference, mimicking education' an unorganised machine can be trained to perform any task that a Turing machine can carry out, provided the number of 'neurons' is sufficient. Turing proposed simulating both the behaviour of (...) the network and the training process by means of a computer program. We outline Turing's connectionist project of 1948. (shrink)

It is not widely realised that Turing was probably the first person to consider building computing machines out of simple, neuron-like elements connected together into networks in a largely random manner. Turing called his networks unorganised machines. By the application of what he described as appropriate interference, mimicking education an unorganised machine can be trained to perform any task that a Turing machine can carry out, provided the number of neurons is sufficient. Turing proposed simulating both the behaviour of (...) the network and the training process by means of a computer program. We outline Turing's connectionist project of 1948. (shrink)

Psychoanalysis is often divided into two parts: the clinical theory and the metapsychology. Recent historical and philosophical work has led some psychoanalysts to argue that the metapsychology is a cryptic biology and not a psychological theory at all. Evidence for this view is largely that metapsychological concepts can be traced to Freud's "Project for a Scientific Psychology", in which he seems to argue that systems of neurons perform both psychological and neuro-physiological functions. The conclusion these writers have drawn is (...) that Freud's metapsychology represents an attempt to unify two putatively incommensurable conceptual frameworks: the psychological and the physiological. ;In the first chapter I review the dispute between Wernicke and Freud on the issue of aphasia and place it in the context of 19th century psychological explanatory traditions. One of these traditions, developed by Franz Joseph Gall, predominates in Wernicke's work. The other tradition, associationism as developed by John Stuart Mill and Alexander Bain, predominates in Freud's critique of Wernicke. I suggest that Wernicke's cerebral localization strategy amounts to a type-type identity theory, and that Freud presented both empirical and conceptual reasons for rejecting this commitment. ;In the second chapter I explicate Freud's "Project" and chapter VII of The Interpretation of Dreams. In the latter, I argue, Freud develops a version of functionalism. His break with his neurological background is exemplified by his insistence that psychology is autonomous. ;In the third chapter I evaluate critically the arguments presented by Merton Gill, George Klein, and Roy Schaffer that purport to show Freud's metapsychology is not a psychology at all, but a neuro-biology. Against this view I suggest that Freud describes mental structures that serve various design functions. These structures, attributed to persons by the metapsychology of infantile wishes and regression, are cognitively impenetiable. The notion that the design or functional architecture of a system is cognitively impenetiable is used to account for the protracted nature, perhaps interminability, of psychoanalytic therapy. Freud's therapeutic pessimism has its roots in theory rather than therapeutic failure. (shrink)

Creating focal lesions in primary visual cortex (V1) provides an opportunity to study the role of extra-geniculo-striate pathways for activating extrastriate visual cortex. Previous studies have shown that more than 95% of neurons in macaque area V2 and V3 stop firing after reversibly cooling V1 [1,2,3]. However, no studies on long term recovery in areas V2, V3 following permanent V1 lesions have been reported in the macaque. Here we use macaque fMRI to study area V2, V3 activity patterns from (...) 1 to 22 months after lesioning area V1. We find that visually driven BOLD responses persist inside the V1-lesion projection zones (LPZ) of areas V2 and V3, but are reduced in strength by ,70%, on average, compared to prelesion levels. Monitoring the LPZ activity over time starting one month following the V1 lesion did not reveal systematic changes in BOLD signal amplitude. Surprisingly, the retinotopic organization inside the LPZ of areas V2, V3 remained similar to that of the non-lesioned hemisphere, suggesting that LPZ activation in V2, V3 is not the result of input arising from nearby (non-lesioned) V1 cortex. Electrophysiology recordings of multi-unit activity corroborated the BOLD observations: visually driven multi-unit responses could be elicited inside the V2 LPZ, even when the visual stimulus was entirely contained within the scotoma induced by the V1 lesion. Restricting the stimulus to the intact visual hemi-field produced no significant BOLD modulation inside the V2, V3 LPZs. We conclude that the observed activity patterns are largely mediated by parallel, V1-bypassing, subcortical pathways that can activate areas V2 and V3 in the absence of V1 input. Such pathways may contribute to the behavioral phenomenon of blindsight. (shrink)

The first brief description is given of a project aimed at searching for the neural correlates of consciousness through computer simulation. The underlying model is based on the known circuitry of the mammalian nervous system, the neuronal groups of which are approximated as binary composite units. The simulated nervous system includes just two senses - hearing and touch - and it drives a set of muscles that serve vocalisation, feeding and bladder control. These functions were chosen because of their relevance (...) to the earliest stages of human life, and the simulation has been given the name CyberChild. The system's pain receptors respond to a sufficiently low milk level in the stomach, if there is simultaneously a low level of blood sugar, and also to a full bladder and an unchanged diaper. It is believed that it may be possible to infer the presence of consciousness in the simulation through observations of CyberChild's behaviour, and from the monitoring of its ability to ontogenetically acquire novel reflexes. The author has suggested that this ability is the crucial evolutionary advantage of possessing consciousness. The project is still in its very early stages, and although no suggestion of consciousness has yet emerged, there appears to be no fundamental reason why consciousness could not ultimately develop and be observed. (shrink)

The discrepancy between syntax and semantics is a painstaking issue that hinders a better comprehension of the underlying neuronal processes in the human brain. In order to tackle the issue, we at first describe a striking correlation between Wittgenstein's Tractatus, that assesses the syntactic relationships between language and world, and Perlovsky's joint language-cognitive computational model, that assesses the semantic relationships between emotions and “knowledge instinct”. Once established a correlation between a purely logical approach to the language and computable psychological activities, (...) we aim to find the neural correlates of syntax and semantics in the human brain. Starting from topological arguments, we suggest that the semantic properties of a proposition are processed in higher brain's functional dimensions than the syntactic ones. In a fully reversible process, the syntactic elements embedded in Broca's area project into multiple scattered semantic cortical zones. The presence of higher functional dimensions gives rise to the increase in informational content that takes place in semantic expressions. Therefore, diverse features of human language and cognitive world can be assessed in terms of both the logic armor described by the Tractatus, and the neurocomputational techniques at hand. One of our motivations is to build a neuro-computational framework able to provide a feasible explanation for brain's semantic processing, in preparation for novel computers with nodes built into higher dimensions. (shrink)

I joined The Hastings Center this past summer, after graduating from Duke University, where I researched advancements in neuroscience and genomics and their import for law, ethics, and policy. This research required, to an extent, faith in the idea that researchers can identify pathways by which genes combine with epigenetic and environmental factors to affect neuronal activity and influence behaviors. Throughout my first months here, I have puzzled over broad critiques of “genomic hype” in recent literature, which clash with the (...) optimistic rhetoric found in the Human Genome Project and the Precision Medicine Initiative. (shrink)

Many years after the publication of “A Logical Calculus of the Ideas Immanent in Nervous Activity,” Warren McCulloch gave Walter Pitts credit for contributing his knowledge of modular mathematics to their joint project. In 1941 I presented my notions on the flow of information through ranks of neurons to Rashevsky’s seminar in the Committee on Mathematical Biology of the University of Chicago and met Walter Pitts, who then was about seventeen years old. He was working on a mathematical theory (...) of learning and I was much impressed. He was interested in problems of circularity, how to handle regenerative nervous activity in closed loops....For two years Walter and I worked on these problems whose solution depended upon modular mathematics of which I knew nothing, but Walter did.. In this paper, we will fill in some of the details regarding Pitts’s interest in problems of circularity, regenerative activity in closed loops of neurons, and modular mathematics, and the way in which they relate to “A Logical Calculus.”. (shrink)

Studies have shown that both serotonin and glutamate receptor systems play a crucial role in the mechanisms underlying drug-induced synesthesia. The specific nature of these mechanisms, however, continues to remain elusive. Here we propose two distinct hypotheses for how synesthesia triggered by hallucinogens in the serotonin-agonist family may occur. One hypothesis is that the drug-induced destabilization of thalamic projections via GABAergic neuronal circuits from sensory areas leads to a disruption of low-level, spontaneous integration of multisensory stimuli. This sort of integration (...) regularly occurs when spatial and temporal attributes match. Destabilization of feedback loops, however, can result in incongruent experiences or binding of random thalamus activation with sensory input in a particular sensory modality. The second hypothesis builds on embodied cognition, cases in which visual images of external stimuli activate task-related neural regions. On this proposal, binding processes that do not normally generate awareness become accessible to consciousness as a result of decreased attentional discrimination among incoming stimuli. (shrink)

In Search of Lost Culture: From Neuroimaging via Critical Neuroscience to Cultural Neuroscience – and back to Critique. The availability of new technologies for visualizing brain activity generated great expectations to identify the centers responsible for human action and behavior and to “reduce” all mental processes to neuronal states. Some scientists even called society to adapt to the new insights from brain research by giving up outdated concepts of autonomy and free will. This project spurred harsh critiques from philosophy, sociology, (...) and cultural studies, diagnosing the rise of a new phrenology. A critical neuroscience group took up these criticisms and pledged for a more nuanced reflection about the political, historical and ethical contexts and implications of current neuroscience and argued for an integration of societal concerns into the research agenda – rather similar to the agenda for responsible research of the EU. With the development of more sophisticated visualization strategies, new sub‐disciplines emerged, integrating sociocultural aspects into neuroimaging. Social and cultural neuroscience replaced overstated reductionist claims without leaving the overarching naturalist epistemology, but extending the ontological realm. New research objects such as empathy, religion or ‘Western’ vs. ‘East‐Asian’ attitudes of thinking started to populate the research domain. Especially cultural neuroscience was widely celebrated as new scientific bridge across the nature‐culture gulf. A closer look, however, reveals that this claim and the popular success of cultural neuroscience are based on a decisive lack of conceptual clarity. ‘Culture’ functions as fuzzy denominator for a broad range of social phenomena with unknown links to neurophysiological processes but visualized as brain states. Instead of implementing more reflexive forms of research, cultural neuroscience stabilizes problematic stereotypes and racist attitudes by an expansion of neuro‐culture. In light of this deflation of interdisciplinary cooperation a more radical critique of this ideology seems in place. (shrink)

The following interview explores neuroscientist Christof Koch's participation in the adversarial collaboration, testing the integrated information theory (IIT) of consciousness against the global neuronal workspace theory (GNW). The interview offers a current update on the adversarial project and then pivots to Koch's responses to three standing critiques of IIT, which include the inexactness of IIT's measures of the neural correlates of consciousness, the charge that IIT implies an unwieldy panpsychism, and the claim that IIT conflates its measures with consciousness.

In recent years increasing attention has been given to systematic comparison of theories of consciousness. Laudable practical projects have emerged in this regard, such as adversarial collaboration and the development of databases lending themselves to comparisons of empirical support for theories. In addition to the practical advances, theoretical advances have been made, such as a list of issues a theory of consciousness must address. We propose adding the issue of the ontogenetic emergence (O-emergence) of consciousness to the list of issues (...) we use to evaluate theories of consciousness. O-emergence concerns how and when consciousness emerges ontogenetically in human beings. The underlying assumption is that there exists a point in the development of a human individual before which that individual is not and cannot be conscious. This assumption, in turn, depends on a widely shared assumption of cognitive neuroscience, which is that consciousness somehow depends on — or derives from — brain activity. In this paper, we lay out the O-emergence criterion and investigate whether it can be accounted for within the Global Neuronal Workspace theory, the Self-Organizing Meta-representational Account, and the Reorganization of Elementary Functions framework. (shrink)