Do patients with schizophrenia benefit from a self-referential memory bias?

BACKGROUND

Self-referential processing (i.e. linking internal and external stimuli to one's own self) has received scant attention thus far in schizophrenia. This type of processing is a key component of social cognition and thought to be important for adaptive social functioning. Memory studies in healthy subjects have shown that stimuli processed with reference to the self are better remembered than stimuli processed in other semantic forms. It is not known whether schizophrenia patients benefit from such a memory boost for self-referenced information.

METHODS

Twenty-five schizophrenia patients and 22 controls were assessed with a self-referential recognition memory paradigm. During an encoding phase, participants rated personality adjectives in each of three conditions: (1) structural features (uppercase or lowercase letters?); (2) social desirability (is adjective socially desirable or not?); or (3) self-referential (does adjective describe me or not?). Recognition memory for these personality adjectives was then tested during an unexpected yes-no recognition test.

RESULTS

Patients and controls were comparable in memory performance for the structural (p=0.12) and social desirability (p=0.30) conditions. In contrast, patients showed significantly reduced recognition sensitivity compared to controls for the self-referential condition (p=0.03).

DISCUSSION

Compared to healthy controls, patients with schizophrenia did not benefit from a memory boost for self-referenced information. Such impaired self-referential memory may be associated with abnormal function of the medial prefrontal cortex. The inability to enhance memory for personally relevant information may partly explain poor social functioning in schizophrenia patients.