Stuart P. Wilson

The University of Sheffield | Sheffield · Department of Psychology (Faculty of Science)

Robotics is increasingly seen as a useful test bed for computational models of the brain functional architecture underlying animal behavior. We provide an overview of past and current work, focusing on probabilistic and dynamical models, including approaches premised on the free energy principle, situating this endeavor in relation to evidence that...

Advances in sequencing techniques have made comparative studies of gene expression a current focus for understanding evolutionary and developmental processes. How- ever, insights into the spatial expression of genes have been limited by a lack of robust methodology. To overcome this obstacle, we developed methods and software tools for quantifying...

Tessellations emerge in many natural systems, and the constituent domains often contain regular patterns, raising the intriguing possibility that pattern formation within adjacent domains might be correlated by the geometry, without the direct exchange of information between parts comprising either domain. We confirm this paradoxical effect, by sim...

The functional organization of the mammalian brain can be considered to form a layered control architecture, but how this complex system has emerged through evolution and is constructed during development remains a puzzle. Here we consider brain organization through the framework of constraint closure, viewed as a general characteristic of living s...

In the classic Chemoaffinity theory, the retinotectal axon projection is thought to use pairs of orthogonal signalling gradients in the retina to specify the eventual location of synapses made on the surface of the tectum/superior colliculus. Similar orthogonal gradients in the tectum provide a coordinate system which allows the axons to match thei...

Advances in sequencing techniques have made comparative studies of gene expression a current focus for understanding evolutionary and developmental processes. However, insights into the spatial expression of genes have been limited by a lack of robust methodology. We therefore developed a set of algorithms for quantifying and comparing tissue-wide...

Tessellations emerge in many natural systems, and the constituent domains often contain regular patterns, raising the intriguing possibility that pattern formation within adjacent domains might be correlated by the geometry, without the direct exchange of information between parts comprising either domain. We confirm this paradoxical effect, by sim...

Motivation modulates behaviour depending upon contextual and internal cues. Like animals, successful artificial agents must implement different behavioural strategies in order to satisfy dynamical needs. Such causal factors emerge from internal homeostatic or allostatic processes, as well as from external stimuli or threats. However, when two or mo...

Motivation modulates behaviour depending upon contextual and internal cues. Like animals, successful artificial agents must implement different behavioural strategies in order to satisfy dynamical needs. Such causal factors emerge from internal homeostatic or allostatic processes, as well as from external stimuli or threats. However, when two or mo...

Brain development relies on an interplay between genetic specification and self-organization. Striking examples of this relationship can be found in the somatosensory brainstem, thalamus, and cortex of rats and mice, where the arrangement of the facial whiskers is preserved in the arrangement of cell aggregates to form precise somatotopic maps. We...

Brain development relies on an interplay between genetic specification and self-organization. Striking examples of this relationship can be found in the somatosensory brainstem, thalamus, and cortex of rats and mice, where the arrangement of the facial whiskers is preserved in the arrangement of cell aggregates to form precise somatotopic maps. We...

Brain development relies on an interplay between genetic specification and self-organization. Striking examples of this relationship can be found in the somatosensory brainstem, thalamus, and cortex of rats and mice, where the arrangement of the facial whiskers is preserved in the arrangement of cell aggregates to form precise somatotopic maps. We...

Brain development relies on an interplay between genetic specification and self-organization. Striking examples of this relationship can be found in the somatosensory brainstem, thalamus, and cortex of rats and mice, where the arrangement of the facial whiskers is preserved in the arrangement of cell aggregates to form precise somatotopic maps. We...

Developmental dynamics in Boolean models of gene networks self-organize, either into point attractors (stable repeating patterns of gene expression) or limit cycles (stable repeating sequences of patterns), depending on the network interactions specified by a genome of evolvable bits. Genome specifications for dynamics that can map specific gene ex...

Successful demonstrations of novel short-cut taking by animals, including humans, are open to interpretation in terms of learning that is not necessarily spatial. A classic example is that of Tolman, Ritchie, and Kalish (1946) who allowed rats to repeat a sequence of turns through the corridors of a maze to locate a food reward. When the entrance t...

Anonymised data record. (CSV)

Huddling behaviour in neonatal rodents reduces the metabolic costs of physiological thermoregulation. However, animals continue to huddle into adulthood, at ambient temperatures where they are able to sustain a basal metabolism in isolation from the huddle. This 'filial huddling' in older animals is known to be guided by olfactory rather than therm...

Fitted growth curves for mice conceived and reared at different environment temperatures by Yamauchi (1983)

Thermoregulatory huddling behaviours dominate the early experiences of developing rodents, and constrain the patterns of sensory and motor input that drive neural plasticity. Huddling is a complex emergent group behaviour, thought to provide an early template for the development of adult social systems, and to constrain natural selection on metabol...

Repetition suppression refers to a reduction in the cortical response to a novel stimulus that results from repeated presentation of the stimulus. We demonstrate repetition suppression in a well established computational model of cortical plasticity, according to which the relative strengths of lateral inhibitory interactions are modified by Hebbia...

Supplementary materials and methods. Table of parameters and description of the homeostatic mechanisms used in pre-training. (PDF)

Supplementary results. Exploration of the limit cases in which plasticity is restricted to either the afferent or inhibitory interactions in the model. (PDF)

A thermodynamic model of thermoregulatory huddling interactions between endotherms is developed. The model is presented as a Monte Carlo algorithm in which animals are iteratively exchanged between groups, with a probability of exchanging groups defined in terms of the temperature of the environment and the body temperatures of the animals. The tem...

A thermodynamic model of thermoregulatory huddling interactions between endotherms is developed. The model is presented as a Monte Carlo algorithm in which animals are iteratively exchanged between groups, with a probability of exchanging groups defined in terms of the temperature of the environment and the body temperatures of the animals. The tem...

Source code required to reproduce all figures from the main text. Contains i) a standalone python script for recreating Fig 1, ii) an efficient c++ implementation of the evolutionary algorithm using the Monte Carlo huddling model for generating the data from which Figs 2–4 can be recreated, and iii) an efficient c++ implementation of the evolutiona...

Self-organization and natural selection are fundamental forces that shape the natural world. Substantial progress in understanding how these forces interact has been made through the study of abstract models. Further progress may be made by identifying a model system in which the interaction between self-organization and selection can be investigat...

Self-organization and natural selection are fundamental forces that shape the natural world. Substantial progress in understanding how these forces interact has been made through the study of abstract models. Further progress may be made by identifying a model system in which the interaction between self-organization and selection can be investigat...

Self-organization and natural selection are fundamental forces that shape the natural world. Substantial progress in understanding how these forces interact has been made through the study of abstract models. Further progress may be made by identifying a model system in which the interaction between self-organization and selection can be investigat...

We consider the problem of sensorimotor co-ordination in mammals through the lens of vibrissal touch, and via the methodology of embodied computational neuroscience—using biomimetic robots to synthesize and investigate models of mammalian brain architecture. The chapter focuses on five major brain sub-systems and their likely role in vibrissal syst...

Endotherms such as rats and mice huddle together to keep warm. The huddle is considered to be an example of a self-organising system, because complex properties of the collective group behaviour are thought to emerge spontaneously through simple interactions between individuals. Groups of rodent pups display two such emergent properties. First, hud...

In this article, we review functional organization in sensory cortical regions-how the cortex represents the world. We consider four interrelated aspects of cortical organization: (1) the set of receptive fields of individual cortical sensory neurons, (2) how lateral interaction between cortical neurons reflects the similarity of their receptive fi...

S1 somatotopic maps refers to spatial patterns in the functional organization of neuronal responses in the mammalian primary somatosensory cortex (S1/SI). Here the term ‘map’ refers to a population of neurons that respond selectively to the presence of stimuli that collectively sample from an underlying stimulus space. Maps are referred to as ‘soma...

What, if anything, is the functional significance of spatial patterning in cortical feature maps? We ask this question of four major theories of cortical map formation: self-organizing maps, wiring optimization, place coding, and reaction-diffusion. We argue that i) self-organizing maps yield spatial patterning only as a byproduct of efficient mech...

Self-organising maps can recreate many of the essential features of the known functional organisation of primary cortical areas in the mammalian brain. According to such models, cortical maps represent the spatial-temporal structure of sensory and/or motor input patterns registered during the early development of an animal, and this structure is de...

I suggest how a new type of biohybrid society --- a huddle of neonatal rat pups comprising biological and synthetic litttermates --- could be used to model the interaction between self-organisation at the neural level and self-organisation at the level of group behaviours.

Natural design is an interaction of both adaptive evolutionary forces and generative developmental processes --- evo-devo. We consider how evo-devo principles can be applied to the design of living machines, and how biohybrid societies (comprising machines and organisms) may be used as a new form of scientific model.

Huddling by endotherms is an important model through which to study the emergence of complexity. Canals et al. (2011) have recently described the emergence of huddling in rodents as a phase transition mediated by the ambient environmental temperature [1]. We present an agent-based model as a minimal account of the reported transition to huddling at...

Analysis of spike timing. Spike histograms were constructed for neurons at different locations in (shown in successive panels). In each panel, rows correspond to different inter-whisker deflection intervals (), and columns show progressive simulation time. Each pixel shows the average spike count, across 5000 trials, in a window. Histograms are ali...

Constraints on the timing of axonal propagation. The delay on the onset of inhibition, , required to make excitation and inhibition from the same whisker arrive coincidently, is plotted for varying inhibitory connection speeds at three locations in L2/3. Solutions to the equation are plotted for three different L4 to L2/3 inter-soma distances: Firs...

Predicted responses to additional whiskers. Responses across a large region of barrel cortex were generated by deflecting increasing numbers of whiskers. The top panel shows the mean spike count, over 5000 trials, to deflection of whisker A followed by whisker B after intervals ranging to (see legend). Ticks along the –axis mark the location of the...

The place theory proposed by Jeffress (1948) is still the dominant model of how the brain represents the movement of sensory stimuli between sensory receptors. According to the place theory, delays in signalling between neurons, dependent on the distances between them, compensate for time differences in the stimulation of sensory receptors. Hence t...

Based on measuring responses to rat whiskers as they are mechanically stimulated, one recent study suggests that barrel-related areas in layer 2/3 rat primary somatosensory cortex (S1) contain a pinwheel map of whisker motion directions. Because this map is reminiscent of topographic organization for visual direction in primary visual cortex (V1) o...

Rats' whiskers convey tactile information to the somatosensory cortex, where layer 4 neurons are clustered into barrels, each responding primarily to input from one principal whisker (PW). The spatial arrangement of the barrels reflects the spatial arrangement of the whiskers on the animal's snout, thus representing the whiskers in a somatotopic ma...

Using desktop, computer-simulated virtual environments (VEs), the authors conducted 5 experiments to investigate blocking of learning about a goal location based on Shape B as a consequence of preliminary training to locate that goal using Shape A. The shapes were large 2-dimensional horizontal figures on the ground. Blocking of spatial learning wa...

The primary somatosensory cortex contains a topographic map of the body surface, with two notable discontinuities—the representation of the face is next to that of the hands, and that of the feet is next to the genitals. Farah [Why does the somatosensory homunculus have hands next to face and feet next to genitals? a hypothesis. Neural Computation...

Based on measuring responses to rat whiskers as they are mechanically stimulated, one recent study suggests that barrel- related areas in layer 2/3 rat primary somatosensory cortex (S1) contain a pinwheel map of whisker motion directions. Because this map is reminiscent of topographic organization for visual direction in primary visual cortex (V1)...