Collerton et al./Why people see things that are not there: BBS Call for Commentators

Dear Dr. Qwerty, If you would like to be considered a potential commentator, or you would like to suggest one, please follow the instructions below. NOTE: Your proposal and/or suggestions should be submitted via the new Online Commentary Proposal system no later than March 7, 2005. The following target article has recently been accepted: "Why people see things that are not there: A novel Perception and Attention Deficit model for recurrent complex visual hallucinations" Daniel Collerton, Elaine Perry, and Ian McKeith ========================================================================= NEW BBS CALL INSTRUCTIONS ========================================================================= Please DO NOT respond to this email. If you wish to submit a proposal for commentary and/or suggest potential commentators, please go to the new Online Commentary Proposal System at the following URL: http://www.bbsonline.org/perl/commentary/commproposal?authordir=Collerton-0… Note: Commentators must be BBS Associates, or suggested by a BBS Associate. If you are not a BBS Associate, please follow the instructions linked below: http://www.bbsonline.org/Instructions/associnst.html ========================================================================= TARGET ARTICLE INFORMATION ========================================================================= TARGET ARTICLE: Why people see things that are not there: A novel Perception and Attention Deficit model for recurrent complex visual hallucinations AUTHORS: Daniel Collerton, Elaine Perry, and Ian McKeith ABSTRACT: As many as two million people in the UK repeatedly see people, animals and objects that have no objective reality. Hallucinations on the border of sleep, dementing illnesses, delirium, eye disease, and schizophrenia account for 90% of these. The remainder have rarer disorders. We review existing models of recurrent complex visual hallucinations (RCVH) in the awake person, including cortical irritation, cortical hyperexcitability, and cortical release, top down activation, misperception, dream intrusion, and interactive models. We provide evidence that these can neither fully account for the phenomenology of RCVH, nor for variations in the frequency of RCVH in different disorders. We propose a novel Perception and Attention Deficit model for RCVH. A combination of impaired attentional binding and poor sensory activation of a correct proto-object, in conjunction with a relatively intact scene representation, bias perception to allow the intrusion of a hallucinatory protoobject into a scene perception. Incorporation of this image into a context specific hallucinatory scene representation accounts for repetitive hallucinations. We suggest that these impairments are underpinned by disturbances in a lateral frontal cortex –ventral visual stream system. We show how the frequency of RCVH in different diseases is related to the coexistence of attentional and visual perceptual impairments; how attentional and perceptual processes can account for their phenomenology; and that diseases and other states with high rates of RCVH have cholinergic dysfunction in both frontal cortex and the ventral visual stream. Several tests of the model are indicated, together with a number of treatment options that it generates. KEYWORDS: Blindness; Charles Bonnet; cholinergic; cortical release; delirium; dementia; dream intrusion; hallucination; Perception and Attention Deficit model; schizophrenia. FULL TEXT: http://www.bbsonline.org/Preprints/Collerton-09122003/Referees/ This article has been accepted for publication in Behavioral and Brain Sciences (BBS), an international, interdisciplinary journal providing Open Peer Commentary on important and controversial current research in the biobehavioral and cognitive sciences. The Calls are sent to 10,000 BBS Associates, so there is no expectation (indeed, it would be calamitous) that each recipient should comment on every occasion! Please DO NOT prepare a commentary unless you eventually receive a formal invitation, indicating that it was possible to include your name on the final list, which is constructed so as to balance areas of expertise and frequency of prior commentaries in BBS. To help you decide whether you would be an appropriate commentator for this article, an electronic draft is retrievable at the URL that follows the abstract and keywords above. ========================================================================= NEW BBS CALL INSTRUCTIONS ========================================================================= Please DO NOT respond to this email. If you wish to submit a proposal for commentary and/or suggest potential commentators, please go to the new Online Commentary Proposal System at the following URL: http://www.bbsonline.org/perl/commentary/commproposal?authordir=Collerton-0… Note: Commentators must be BBS Associates, or suggested by a BBS Associate. If you are not a BBS Associate, please follow the instructions linked below: http://www.bbsonline.org/Instructions/associnst.html ========================================================================= Barbara Finlay - Editor Paul Bloom - Editor Behavioral and Brain Sciences bbs(a)bbsonline.org http://www.bbsonline.org -------------------------------------------------------------------