Altered emotional modulation of associative memory in first episode schizophrenia: An fMRI study

Alterations of associative memory, resulting from perturbations within the medial temporal lobe, are well established in schizophrenia. So far, all the studies having examined associative memory in schizophrenia have limited ecological validity, as people experience various emotional stimuli in their life. As such, emotion must be taken into account in order to fully understand memory. Thus, we designed an fMRI study aimed at investigating neural correlates of the effects of emotions on associative memory in schizophrenia. Twenty-four first episode schizophrenia (FES) patients and 20 matched controls were instructed to memorize 90 pairs of standardized pictures during a scanned encoding phase. Each of the 90 pairs was composed of a scene and an unrelated object. Furthermore, trials were either neutral or emotional as a function of the emotional valence of the scene comprising each pair. FES patients exhibited lower performance for both conditions than controls, with greater deficits in regard to emotional versus neutral associations. fMRI analyses revealed that these deficits were related to lower activations in mnemonic and limbic regions. This study provides evidence of altered associative memory and emotional modulation in schizophrenia, resulting from dysfunctions in the cerebral networks underlying memory, emotion, and encoding strategies. Together, our results suggest that all these dysfunctions may be targets for new therapeutic interventions known to improve cognitive deficits in schizophrenia.