Jonathan M. Chambers

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Biological computational modellers are becoming increasingly interested in building large, eclectic models, including components on many different computational substrates, both biological and non-biological. At the same time, the rise of the philosophy of embodied modelling is generating a need to deploy biological models as controllers for robots in(More)
Individuals with Parkinson's disease (PD) show marked impairments in their ability to generate self-initiated, or "voluntary", saccadic eye movements. Investigations of visually guided, or "reflexive", saccades have, on the other hand, produced inconclusive results with studies showing response times (RTs) in persons with PD that are slower, faster, or(More)
We present an application of a massively parallel processor array VLSI circuit to the implementation of neural networks in complex architectural arrangements. The work was motivated by existing biologically plausible models of a set of sub-cortical nuclei-the basal ganglia. The model includes 5 layers, each consisting of 16384 leaky integrator neurons, with(More)
2. An endogenous neuronal process? Growing neurophysiological evidence indicates that during decision making single neurons can integrate the sensory evidence in favour of a particular response. Mathematical models can describe the dynamics of this evidence accumulation process (Ratcliff et al, 2003; Reddi & Carpenter, 2000) and promise to connect the(More)
There are two modes of control recognised in the cognitive psychological literature. Controlled processing is slow, requires serial attention to sub-tasks, and requires effortful memory retrieval and decision making. In contrast automatic control is less effortful, less prone to interference from simultaneous tasks, and is driven largely by the current(More)
The basal ganglia (BG) are a group of subcortical nuclei which are believed to be involved in mediating action selection [1]. They are arranged in a series of topogra-phically organised anatomical 'loops,' receiving input from large regions of cortex, and projecting back to the same cortical regions via thalamus. These basal ganglia-thalamocortical (BGTC)(More)
— Analysing complex scenes in detail over wide visual fields requires massive computational resources when performed in parallel. One solution to this problem, used in primates , is active vision. Here detailed analysis is concentrated at a central, foveal, area, while more peripheral areas receive only sufficient analysis to detect phasic stimuli and(More)
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