Differences in Brain Activation between the Retrieval of Specific and Categoric Autobiographical Memories: An EEG Study

Difficulty in retrieving specific autobiographical memories is known as overgeneral autobiographical memory (OGM). OGM has been related with clinical psychopathology (e.g., depression, schizophrenia, etc.). People presenting an OGM style usually recall more repetitive summary-type memories, so-called categoric memories, (e.g., "each time I saw her") rather than specific memories (events occurring on a specific day whose duration does not exceed 24 hours; e.g., "the day I met her"). Differences in brain activation in the search phase of the retrieval process of specific and categoric autobiographical memories are examined using EEG techniques. Fourteen younger adults performed an Autobiographical Memory Task. Results show significant differences in the activation between specific and categoric memories mainly in frontal areas during the 2.5 seconds before the memory recovery. Specific memories were associated with an increased activation of the left prefrontal cortex, while brain activation for categoric memories was less intense. These results support the idea that the activation of prefrontal areas is required to facilitate the process of elaborating specific memories.