David Bourget (Western Ontario)
David Chalmers (ANU, NYU)
Rafael De Clercq
Jack Alan Reynolds
Learn more about PhilPapers
Behavioral and Brain Sciences 27 (6):771-787 (2004)
Based on recent insight into the thalamocortical system and its role in perception and conscious experience, a unified pathophysiological framework for hallucinations in neurological and psychiatric conditions is proposed, which integrates previously unrelated neurobiological and psychological findings. Gamma-frequency rhythms of discharge activity from thalamic and cortical neurons are facilitated by cholinergic arousal and resonate in networks of thalamocortical circuits, thereby transiently forming assemblies of coherent gamma oscillations under constraints of afferent sensory input and prefrontal attentional mechanisms. If perception is based on synchronisation of intrinsic gamma activity in the thalamocortical system, then sensory input to specific thalamic nuclei may merely play a constraining role. Hallucinations can be regarded as underconstrained perceptions that arise when the impact of sensory input on activation of thalamocortical circuits and synchronisation of thalamocortical gamma activity is reduced. In conditions that are accompanied by hallucinations, factors such as cortical hyperexcitability, cortical attentional mechanisms, hyperarousal, increased noise in specific thalamic nuclei, and random sensory input to specific thalamic nuclei may, to a varying degree, contribute to underconstrained activation of thalamocortical circuits. The reticular thalamic nucleus plays an important role in suppressing random activity of relay cells in specific thalamic nuclei, and its dysfunction may be implicated in the biological vulnerability to hallucinations in schizophrenia. Combined with general activation during cholinergic arousal, this leads to excessive disinhibition in specific thalamic nuclei, which may allow cortical attentional mechanisms to recruit thalamic relay cells into resonant assemblies of gamma oscillations, regardless of their actual sensory input, thereby producing an underconstrained perceptual experience. Key Words: Charles Bonnet syndrome; gamma oscillations; hallucinations; late paraphrenia; Lewy body dementia; perception; schizophrenia; thalamocortical system
|Keywords||Charles Bonnet syndrome gamma oscillations hallucinations late paraphrenia Lewy body dementia perception schizophrenia thalamocortical system|
|Categories||categorize this paper)|
Setup an account with your affiliations in order to access resources via your University's proxy server
Configure custom proxy (use this if your affiliation does not provide a proxy)
|Through your library|
References found in this work BETA
No references found.
Citations of this work BETA
Sue Llewellyn (2011). If Waking and Dreaming Consciousness Became de-Differentiated, Would Schizophrenia Result? Consciousness and Cognition 20 (4):1059-1083.
Similar books and articles
Kevin M. Spencer & Robert W. McCarley (2005). Visual Hallucinations, Attention, and Neural Circuitry: Perspectives From Schizophrenia Research. Behavioral and Brain Sciences 28 (6):774-774.
Daniel Collerton, Elaine Perry & Ian McKeith (2005). Why People See Things That Are Not There: A Novel Perception and Attention Deficit Model for Recurrent Complex Visual Hallucinations. Behavioral and Brain Sciences 28 (6):737-757.
Claude Gottesmann (2004). Paradoxical Sleep and Schizophrenia Have the Same Neurobiological Support. Behavioral and Brain Sciences 27 (6):794-795.
André Aleman, Edward H. F. de Haan & René S. Kahn (2004). Underconstrained Perception or Underconstrained Theory? Behavioral and Brain Sciences 27 (6):787-788.
Martin Sarter & Gary G. Berntson (2004). Underconstrained Thalamic Activation + Underconstrained Top-Down Modulation of Cortical Input Processing = Underconstrained Perceptions. Behavioral and Brain Sciences 27 (6):803-804.
Daniel Collerton & Elaine Perry (2004). Thalamocortical Dysfunction and Complex Visual Hallucinations in Brain Disease – Are the Primary Disturbances in the Cerebral Cortex? Behavioral and Brain Sciences 27 (6):789-790.
Ian J. Kirk (2004). A Possible Role for Non-Gamma Oscillations in Conscious Perception: Implications for Hallucinations in Schizophrenia. Behavioral and Brain Sciences 27 (6):798-798.
Anthony C. Meis (2004). Deregulation of the Balance Between Data and Conceptually Driven Processing: A Shift Toward the Conceptual. Behavioral and Brain Sciences 27 (6):800-801.
P. R. (2003). Hallucinations: Synchronisation of Thalamocortical Oscillations Underconstrained by Sensory Input. Consciousness and Cognition 12 (3):413-451.
R. P. Behrendt (2003). Hallucinations: Synchronisation of Thalamocortical ? Oscillations Underconstrained by Sensory Input. Consciousness and Cognition 12 (3):413-451.
Added to index2009-01-28
Total downloads44 ( #35,912 of 1,096,515 )
Recent downloads (6 months)6 ( #34,641 of 1,096,515 )
How can I increase my downloads?