Doctor of Philosophy
Date of Defense
Rob Paul, PhD
David Bryan Robertson
Older adults exhibit reduced accuracy and efficiency for identifying facial emotion expressions yet it is unclear how genetic or cognitive variables influence these findings. This study examined the impact of serotonin transporter polymorphism 5-HTTLPR on patterns of explicit emotion identification accuracy and reaction time (RT) in healthy older adults. The impact of 5-HTTLPR on measures of processing speed, attention, and executive function as well as correlations between cognitive measures and emotion identification measures were also examined. Methods: Forty-one individuals over the age of 50 were genotyped for bi-allelic and tri-allelic variants of 5-HTTLPR and administered an emotion recognition paradigm and tests of cognitive function. Results: Results indicated that individuals carrying low expressing S alleles were significantly slower when identifying expressions of emotion, particularly fear and disgust. A similar pattern of results for fear and disgust was revealed for low expressing S and LG carriers, but these findings were not held after adjustment for multiple comparisons. RTs for happy and neutral faces were correlated with performance on measures of processing speed, attention, and executive function in low expression groups, but these findings were not held after adjustment for multiple comparisons. Conclusions: Overall, this study suggests that possession of low-expressing genetic variants of 5-HTTLPR is associated with diminished emotion identification RT performance among healthy older adults.
Scott, Staci Erin, "Impact of the Serotonin Transporter Polymorphism on Emotion Identification in Healthy Older Adults" (2014). Dissertations. 203.