Associative memory encoding and recognition in schizophrenia: an event-related fMRI study.
BACKGROUND
We used an event-related functional Magnetic Resonance Imaging (fMRI) approach to examine the neural basis of the selective associative memory deficit in schizophrenia.


METHODS
Fifteen people with schizophrenia and 18 controls were scanned during a pair and item memory encoding and recognition task. During encoding, subjects studied items and pairs of visual objects. In a subsequent retrieval task, participants performed an item recognition memory test (old/new decisions) and an associative recognition test (intact/rearranged decisions). The fMRI analysis of the recognition data was restricted to correct items only and a random effects model was used.


RESULTS
At the behavioral level, both groups performed equally well on item recognition, whereas people with schizophrenia demonstrated lower performance on associative recognition relative to the control group. At the brain level, the comparison between associative and item encoding revealed greater activity in the control group in the left prefrontal cortex and cingulate gyrus relative to the schizophrenia group. During recognition, greater left dorsolateral prefrontal and right inferior prefrontal activations were observed in the control group relative to the schizophrenia group.


CONCLUSIONS
This fMRI study implicates the prefrontal cortex among other brain regions as the basis for the selective associative memory encoding and recognition deficit seen in schizophrenia.
Lepage
Martin
M
Brain Imaging Group, Douglas Hospital Research Centre, Verdun, Quebec, Canada. martin.lepage@mcgill.ca
Montoya
Alonso
A
Pelletier
Marc
M
Achim
Amélie M
AM
Menear
Matthew
M
Lal
Samarthji
S
D000328:Adult; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000098:blood supply / Q000503:physiopathology; D021641:Recognition, Psychology / Q000502:physiology*; D012559:Schizophrenia / Q000150:complications* / Q000503:physiopathology
D010100:Oxygen