Background: Poor episodic autobiographical future thinking has recently been reported in 22q11.2 carriers. However, whether these impairments are due to poor language skills or indicate a true episodic autobiographical memory deficit remains unclear. Language impairments are the hallmark of the neuropsychological profile of young children with 22q11DS, but language outcomes in adolescence and young adulthood, especially high-level linguistic skills such as narrative, remain largely unexplored. The aims of this study are first to precisely characterize the narrative abilities of a group of adolescents and young adults with a 22q11DS and normal verbal intellectual functioning, in comparison to a control group. Second, to assess their (past) autobiographical episodic memory and their future episodic thinking abilities. Third, to examine the relationship between linguistic and autobiographical memory skills.
Methods: Fifteen adolescents and young adults with 22q11DS were compared with 15 age- and sex-matched controls. Narrative ability was assessed with a storytelling task and included microstructural, macrostructural, and pragmatic linguistic measures. Episodic autobiographical memory was assessed using a paradigm involving recall of past personal memories and future thinking conditions.
Results: Adolescents and young adults with 22q11DS still struggled with high-level language skills such as storytelling tasks, and all linguistic levels were impaired, i.e., the microstructural, macrostructural, and pragmatic components of narrative. Second, 22q11DS carriers showed poor episodic autobiographical recall of their personal memories and reduced access to sensory details (visual, auditory…) compared to controls. Their poor autobiographical episodic memory skills were independent of language impairment, and there were no effects of age or intellectual level on their autobiographical (past) memories recollection. On the other hand, age and verbal intellectual functioning significantly contributed to their ability to produce episodic narratives in the future thinking condition, suggesting that the future thinking task relies on more complex and intricate factors than pure episodic memory ability.
Conclusions: Verbal narrative impairments did not account for poor recall of personal memories, suggesting dysfunctional episodic memory networks between hippocampi and posterior cortical areas in 22q11DS, where neuroanatomical and neurofunctional alterations have indeed been reported.
