The Effects of Prenatal Alcohol Exposure on Episodic Memory Functioning: A Systematic Review

Abstract

Objective This paper systematically reviews the literature on the effects of prenatal alcohol exposure (PAE) on episodic memory. Specifically, the review focuses on recurring questions of whether memory deficits are consistent across memory domains, whether the impairments are consistent across the stages of episodic memory, and whether the impairments are primary episodic memory impairments or secondary to a global performance deficit or a higher order deficit. Method In total, 33 relevant studies were identified through searches on electronic databases. Journal articles were limited to those that included human subjects and that were published in English-language journals. Results The vast majority of reviewed studies examined memory in school-aged children and adolescents. Twenty-three studies examined verbal memory and 19 studies examined visual-spatial memory. Although all of the reviewed studies examined encoding of new material, only 10 studies examined retention of the learned material over time. Ten studies controlled for IQ, either statistically or with matched controls, when analyzing memory task performance. Conclusion In general, studies show that PAE results in impaired verbal and visual-spatial episodic memory performance in affected individuals and these impairments are unlikely to be secondary to a global impairment. However, impairments on some memory tests are specific to the encoding stage, whereas retention is relatively spared; suggesting that the episodic memory deficit might be influenced, at least in part, by higher order cognitive processes.