[Prefrontal dysfunction in schizophrenia: implication is associative recognition]

We used an event related functional magnetic resonance imaging (fMRI) method to examine the neural basis of associative recognition memory deficit in schizophrenia.

Fifteen people with schizophrenia and 18 healthy control subjects were scanned with fMRI while performing a memory task (coding and recognition) of visual objects. During coding, the subjects studied items and pairs of items. During recovery, the subjects had to recognize items (old/new decisions) and recognize associations (intact/rearranged decisions). The study design was based on a random effect model and the fMRI analysis was restricted to correct items only.

At the behavioral level, both groups performed equally well on item recognition, whereas people with schizophrenia demonstrated poorer performance on associative recognition. At the brain level, comparison between associative and item recognition tasks revealed greater left dorsolateral prefrontal and right inferior prefrontal activations in the control group relative to the schizophrenia group.

The findings of this fMRI study suggest the prefrontal cortex as the basis for the selective memory deficit for associative recognition observed in schizophrenia.