Episodic memory decline is associated with deficits in coherence of discourse

This study investigates coherence of discourse in the production of autobiographical narratives by individuals with aMCI. Autobiographical interviews were analyzed to determine whether reduced episodic recall was related to deficits in discourse coherence. A coherence rating scale was used to evaluate relatedness of the autobiographical details produced by participants to the topic of discourse. Interviews were transcribed, segmented into details, and divided into sets of episodic, semantic, or supplementary information, which were subsequently analysed with the coherence rating scale. We predicted that the known episodic deficits observed in aMCI could also affect the retrieval of coherent episodic information. The results revealed deficits in coherence could be found in both episodic and semantic information in the aMCI group. These results suggest that the cognitive deficits experienced by individuals with aMCI may go beyond their known difficulty in recalling episodic details, as they also affect the controlled retrieval of both episodic and semantic information.