PMID- 18423984
OWN - NLM
STAT- MEDLINE
DCOM- 20080926
LR  - 20211020
IS  - 0920-9964 (Print)
IS  - 0920-9964 (Linking)
VI  - 103
IP  - 1-3
DP  - 2008 Aug
TI  - Altered 'three-flash' illusion in response to two light pulses in schizophrenia.
PG  - 275-82
LID - 10.1016/j.schres.2008.03.002 [doi]
AB  - BACKGROUND: Disorganization is a core dysfunction in schizophrenia. Coherent 
      thought and behavior rely on the interactive neural responses to temporally 
      discrete external events. Previous studies have demonstrated that a single visual 
      stimulus (event) is abnormally affected by another (as in backward masking), but 
      the integration (or 'synthesis') of temporally discrete events remains largely 
      unexplored in schizophrenia. We examined the perceived interaction of two 
      elementary visual events in schizophrenia patients, using a psychophysical 
      approach. METHODS: Two brief, spatially-coincident foveal light pulses (5 ms) 
      were presented with different inter-stimulus intervals (ISIs). At ISIs around 100 
      ms, a substantial proportion of the light pulse pairs was paradoxically perceived 
      as three flashes, a known phenomenon in normal subjects. The subjects reported 
      the number of flashes perceived ('one', 'two' or 'three'). RESULTS: Schizophrenia 
      patients (n=28) reported fewer 'three flashes' than normal controls (n=26) at the 
      ISIs where 'three flash' reports were greatest in normal subjects (90 to 110 ms). 
      On the other hand, at longer ISIs (130-310 ms) patients reported 'three flashes' 
      in more trials than did normal subjects. The perception of three flashes in 
      patients was correlated with certain aspects of clinical status, including the 
      positive and general subscales of the PANSS. DISCUSSION: The alteration of the 
      'three-flash' illusion in schizophrenia suggests that the synthesis of discrete 
      visual events is temporally 'dilated' or distorted, which might contribute to 
      disorganized thought and behavior.
FAU - Norton, Dan
AU  - Norton D
AD  - McLean Hospital, United States.
FAU - Ongur, Dost
AU  - Ongur D
FAU - Stromeyer, Charles 3rd
AU  - Stromeyer C 3rd
FAU - Chen, Yue
AU  - Chen Y
LA  - eng
GR  - R01 MH061824/MH/NIMH NIH HHS/United States
GR  - R01 MH061824-07/MH/NIMH NIH HHS/United States
GR  - 61824/PHS HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
DEP - 20080418
PL  - Netherlands
TA  - Schizophr Res
JT  - Schizophrenia research
JID - 8804207
SB  - IM
MH  - Adult
MH  - Contrast Sensitivity
MH  - Discrimination Learning
MH  - Female
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - *Optical Illusions
MH  - Photic Stimulation
MH  - Psychiatric Status Rating Scales
MH  - Psychotic Disorders/*diagnosis/psychology
MH  - Reaction Time
MH  - Reference Values
MH  - Schizophrenia/*diagnosis
MH  - *Schizophrenic Psychology
PMC - PMC2553681
MID - NIHMS64651
EDAT- 2008/04/22 09:00
MHDA- 2008/09/27 09:00
PMCR- 2009/08/01
CRDT- 2008/04/22 09:00
PHST- 2007/11/26 00:00 [received]
PHST- 2008/02/27 00:00 [revised]
PHST- 2008/03/05 00:00 [accepted]
PHST- 2008/04/22 09:00 [pubmed]
PHST- 2008/09/27 09:00 [medline]
PHST- 2008/04/22 09:00 [entrez]
PHST- 2009/08/01 00:00 [pmc-release]
AID - S0920-9964(08)00142-4 [pii]
AID - 10.1016/j.schres.2008.03.002 [doi]
PST - ppublish
SO  - Schizophr Res. 2008 Aug;103(1-3):275-82. doi: 10.1016/j.schres.2008.03.002. Epub 
      2008 Apr 18.