The relationship between the temperament trait of sensory processing sensitivity and emotional reactivity

Abstract

The dissertation investigated the extent to which the temperament trait of sensory processing sensitivity (SPS) and its interaction with childhood environment, specifically parenting, predict response to emotional stimuli and its neural correlates. As SPS has been conceptualized (Aron and Aron, 1997; Aron, Aron, and Jagiellowicz, 2012), it is characterized by sensitivity to both external and internal stimuli, intense emotions, and a cognitive style characterized by a preference for elaborate processing of information. In Study 1, 101 participants (mean age 19.26; 68 females), selected from a larger pre-screened pool to represent the approximately upper and lower quartiles of SPS, viewed emotionally evocative pictures from the International Affective Picture System (IAPS), and rated their arousal to each. The key result was an interaction in which high SPS participants (compared to low), who reported positive parenting (particularly high parental care, low parental overprotection, and low parental abuse), showed more arousal to positive pictures than to neutral pictures (interaction Β = 0.45, p = 0.01). There was no significant difference between high and low SPS, or interaction of SPS with parenting, in response to viewing negative pictures (vs. neutral pictures). In Study 2, 10 high and 10 low SPS female participants (mean age 18.68) passively viewed IAPS pictures in the fMRI scanner. Data were analyzed for activation in specific hypothesized regions of interest (ROIs), as well as in exploratory whole-brain analyses. In the ROI analysis, high (vs. low) SPS participants, after controlling for neuroticism and introversion, evidenced significantly more activation in the right putamen and globus pallidus in response to positive (vs. neutral) pictures. The whole-brain analysis yielded greater activation for high (vs. low) SPS individuals in a fronto-temporal network in response to positive (vs. neutral) pictures. Except for coordinates in the left claustrum, and the left inferior temporal gyrus, there were no significant interactions of SPS and parenting. Overall, results suggest that individuals high in SPS are more affected than those low in SPS by emotionally positive stimuli, and that those high in SPS may be especially more affected by emotionally positive stimuli when they have had positive parenting.