Startle reactivity to affective imagery during deep and shallow emotional processing in alexithymia

Abstract

Background: We examined startle modulation by emotional imagery and its associations with Heart Rate Variability. Methods: Fifty-four adults (27 alexithymic) imagined Joy and Fear scripts. Physiology was assessed during baseline, initial exposure (under instructions for shallow or deep emotion processing) and uninstructed re-exposure. Results: Deep processing resulted in larger and faster responses during Fear at exposure for alexithymics. Higher HRV was related to larger startle during exposure/Deep processing in alexithymia. At re-exposure, higher HRV was related to larger startles during Fear/Deep processing for controls, but to smaller responses for alexithymics. Discussion: HRV is typically positively related to expected fear-potentiated startle. This pattern occurred among alexithymics only during exposure/Deep processing. As deep processing continued in re-exposure, alexithymic fear startle responses were reduced, in relation to better emotion regulation (higher HRV). When exposed to prolonged, intense threat, alexithymics may show overregulated emotional reactivity that is similar for both threatening and non-threatening stimuli. Their increased health concerns may reflect such emotional responses that do not differentiate appropriately between actual symptoms and innocuous body signals.