Relational Memory in Psychosis: Learning Trajectories and Associative Inference

Schizophrenia is characterized by relational memory impairments that disrupt the ability to form novel inferences based on prior knowledge. The current study examined three aspects of relational memory impairments in psychosis. First, do relational memory deficits reflect specific difficulties in learning across repeated exposures? Second, can associative inference deficits be explained by a more general deficit in paired associate learning? Third, are relational memory deficits specific to schizophrenia or do they extend to affective psychosis?

We studied persons with schizophrenia spectrum disorders (n = 244), persons with affective psychosis (n = 77), and healthy control participants (n = 186) with the Associative Inference Paradigm. Participants learned overlapping (A-B, B-C) and non-overlapping (D-E) pairs across multiple training blocks and were later tested on both directly studied (e.g., D-E) and inferred (i.e., A-C) associations.

Persons with psychosis exhibited slower learning, a lower learning ceiling, and increased forgetting when compared to healthy control participants. Critically, associative inference impairments were disproportionally greater in schizophrenia and persisted even after accounting for paired-associate learning deficits.

Our results reveal that relational memory impairments in psychosis reflect difficulties in learning and retaining associations and that their integration, necessary to form novel inferences, is especially impaired.