Language and memory: an investigation of the relationship between autobiographical memory recall and narrative production of semantic and episodic information

Background: The production of autobiographical narratives requires linguistic structures and the ability to access and generate both semantic information and episodic details of personal events. Aims: This study investigated autobiographical narratives produced by individuals with established semantic memory impairments (semantic variant primary progressive aphasia; svPPA) or episodic memory impairments (amnestic mild cognitive impairment; aMCI) in order to investigate whether different categories of memory impairment would manifest different linguistic deficits. Methods & Procedures: We used the Autobiographical Interview and Quantitative Production Analysis methods to investigate linguistic production during autobiographical recall. Additional investigations compared the production of present and past tense inflections in order to look for morpho-syntactic differences in the sets of episodic and semantic information. Outcomes and Results: The results showed that individuals with svPPA produced fewer well-formed sentences when producing episodic details and produced fewer past tense inflections when producing semantic details in comparison to healthy controls. The aMCI group produced fewer episodic utterances but produced a larger number of words in the set of semantic details, in comparison to healthy controls. Conclusions: It is possible that specific demands related to the type of message being conveyed, or high cognitive load during retrieval of episodic information may affect the narration process. Difficulty in the retrieval of episodic information is likely related to reduced production of episodic utterances in individuals with aMCI and may be related to deficits in linguistic production in svPPA. We propose that the results in the set of semantic details are connected to previous findings relating to semantic memory and deficits in discourse coherence in both groups.