Convergence of biological and psychological perspectives on cognitive coordination in schizophrenia

Abstract

Cognitive neuroscience provides a new conceptual framework for psychiatry by showing how psychological processes arise from neuronal activity (Kandel 1998). Conversely, it is possible that psychiatry will influence the future development of cognitive neuroscience by encouraging a better balance between localist and holistic conceptions of brain function. An apparent conflict between these conceptions has been central to the development of neuroscience, with the emphasis upon locally specialized functions emerging as clearly dominant. Neuroanatomy, neurophysiology, neuropsychology, and neuroimaging all show that different regions of the brain process information about different things, and that different cells within regions deal with different aspects of those things. Recent developments in experimental and theoretical neurobiology, however, are leading to an increased emphasis upon interactions that coordinate the activity of locally specialized processors. Here we argue that impairment of these coor-BEHAVIORAL AND BRAIN SCIENCES (2003) Abstract:The concept of locally specialized functions dominates research on higher brain function and its disorders. Locally specialized functions must be complemented by processes that coordinate those functions, however, and impairment of coordinating processes may be central to some psychotic conditions. Evidence for processes that coordinate activity is provided by neurobiological and psychological studies of contextual disambiguation and dynamic grouping. Mechanisms by which this important class of cognitive functions could be achieved include those long-range connections within and between cortical regions that activate synaptic channels via NMDAreceptors, and which control gain through their voltage-dependent mode of operation. An impairment of these mechanisms is central to PCP-psychosis, and the cognitive capabilities that they could provide are impaired in some forms of schizophrenia. We conclude that impaired cognitive coordination due to reduced ion flow through NMDA-channels is involved in schizophrenia, and we suggest that it may also be involved in other disorders. This perspective suggests several ways in which further research could enhance our understanding of cognitive coordination, its neural basis, and its relevance to psychopathology.Keywords: attention; cerebral cortex; cognitive coordination; cognitive neuropsychiatry; cognitive neuropsychology; context disorganization; Gamma rhythms; Gestalt theory; glutamate; grouping; memory; NMDA-receptors; PCP-psychosis; perceptual organization; schizophrenia William A. Phillips, Ph.D., is Professor of Neuropsychology at the University of Stirling, Scotland UK. He has published more than 70 papers on vision, visual memory, perceptual learning, childrens drawings, the effects of brain damage on reading and writing, and the theory of neuronal computation. He was a founder and the first Director of the Center for Cognitive and Computational Neuroscience at the University of Stirling.Steven M. Silverstein, Ph.D., is A...

On the functions, mechanisms, and malfunctions of intracortical contextual modulation

“…We will therefore re-assess the hypothesis that impairment of contextual modulation is such a pathophysiology. For an introduction to and commentary on an earlier version of that hypothesis see Phillips and Silverstein (2003).…”

The dependence of P300 amplitude on gamma synchrony breaks down in schizophrenia

“…Communication and coordination failures between different brain regions may account for a wide range of problems in schizophrenia, from psychosis to cognitive dysfunction (Phillips and Silverstein, 2003). The phenomenology of schizophrenia suggests a disturbance in integration of brain activity through loss of "inner unity" (Kraepelin, 1919) or "cognitive coordination" (Phillips and Silverstein, 2003).…”

“…The phenomenology of schizophrenia suggests a disturbance in integration of brain activity through loss of "inner unity" (Kraepelin, 1919) or "cognitive coordination" (Phillips and Silverstein, 2003). It has been hypothesized that many of the deficits in schizophrenia can be attributed to core abnormalities in the timing, synchronization, and efficiency of neural processes that bind and integrate information from different brain regions, as measured by EEG (Green and Nuechterlein 1999;Spencer et al 2004b).…”

Dynamic Coordination in Brain and Mind

“…Furthermore, they provide evidence that there are variations in those rhythms and mechanisms across cortical regions, so we now need to discover the computational, cognitive, and psychopathological consequences of such variations. Finally, it was agreed that the theories of Friston (1999) and of Phillips and Silverstein (2003) have much in common. Friston suggested that the "disconnection" theory of schizophrenia could be referred to as the "dysconnection" theory.…”

“…Prima facie, NMDA receptors (NMDARs) seem to function as highly selective gain controllers, and thus could help mediate coordination within the cognitive system (Phillips and Singer, 1997). This hypothesis is supported by evidence that NMDAR malfunction or dysregulation is a crucial part of the pathophysiology of cognitive disorganisation in psychosis (Phillips and Silverstein 2003).…”