Brain-performance correlates of working memory retrieval in schizophrenia: a cognitive modeling approach.
Correlations of cognitive functioning with brain activation during a sternberg item recognition paradigm (SIRP) were investigated in patients with schizophrenia and in healthy controls studied at 8 sites. To measure memory scanning times, 4 response time models were fit to SIRP data. The best fitting model assumed exhaustive serial memory scanning followed by self-terminating memory search and involved one intercept parameter to represent SIRP processes not contributing directly to memory scanning. Patients displayed significantly longer response times with increasing memory load and differed on the memory scanning, memory search, and intercept parameters of the best fitting probability model. Groups differed in the correlation between the memory scanning parameter and linear brain response to increasing memory load within left inferior and left middle frontal gyrus, bilateral caudate, and right precuneus. The pattern of findings in these regions indicated that high scanning capacity was associated with high neural capacity among healthy subjects but that scanning speed was uncoupled from brain response to increasing memory load among schizophrenia patients. Group differences in correlation of the best fitting model's scanning parameter with a quadratic trend in brain response to increasing memory load suggested inefficient or disordered patterns of neural inhibition among individuals with schizophrenia, especially in the left perirhinal and entorhinal cortices. The results show at both cognitive and neural levels that disordered memory scanning contributes to deficient SIRP performance among schizophrenia patients.
Brown
Gregory G
GG
Department of Psychiatry, University of California, San Diego, CA, USA. gbrown@ucsd.edu
McCarthy
Gregory
G
Bischoff-Grethe
Amanda
A
Ozyurt
Burak
B
Greve
Doug
D
Potkin
Steven G
SG
Turner
Jessica A
JA
Notestine
Randy
R
Calhoun
Vince D
VD
Ford
Judy M
JM
Mathalon
Daniel
D
Manoach
Dara S
DS
Gadde
Syam
S
Glover
Gary H
GH
Wible
Cynthia G
CG
Belger
Aysenil
A
Gollub
Randy L
RL
Lauriello
John
J
O'Leary
Daniel
D
Lim
Kelvin O
KO
D000328:Adult; D001921:Brain / Q000503:physiopathology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D011930:Reaction Time; D011932:Reading; D021641:Recognition, Psychology; D012559:Schizophrenia / Q000150:complications* / Q000503:physiopathology*; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires