Episodic memory involves recalling personal events such as what you did yesterday, what you had for lunch an hour ago, or the the details of social interactions. Poor episodic memory, a common feature of schizophrenia, limits the ability to form relationships with others.
Now, researchers at the University of California, Los Angeles (UCLA) have discovered that early-stage schizophrenia patients have better recall regarding social events if they are given hints about context. The new findings suggest a potential strategy for memory training for people with this debilitating disease.
For the study, the researchers wanted to investigate whether episodic memory regarding social interactions worsens over the course of the illness. They recruited three groups: people at high risk for psychosis, people who had one episode of psychosis and people with chronic schizophrenia.
Without telling the subjects that they were taking part in a memory test, the researchers showed the participants 24 film clips, depicting friends talking, a car mechanic speaking to a customer, and other ordinary scenes.
Participants then looked at photographs of 24 people featured in the film clips, as well as photos of 24 people who were not in the clips. Researchers asked the subjects to identify which faces just seemed familiar and which faces elicited detailed memories about the specific situations depicted in the film clips.
Volunteers from all three groups were able to identify faces from the film clips, but all demonstrated poor episodic memory in their ability to recall the social situations that matched the faces.
In the second part of the study, participants were shown the photos again and this time were asked to choose one of four sentences describing the situation in which the face had appeared. The participants who were at risk for developing schizophrenia had no trouble with this task. However, those who had already experienced an episode of psychosis or who had chronic schizophrenia had difficulty with this experiment.
According to the researchers, the findings offer several insights:
- The difference among groups in the sentence-selection experiment suggests a subtle change in social memory with the onset of psychosis — once the illness starts, the picture cues aren’t helpful;
- Knowing the importance of providing context as a way to improve social memory in the earliest phase of schizophrenia may help family members and caregivers interact with and support the patients;
- Impaired social episodic memory may be an early symptom of schizophrenia.