Emotion and motivation I: Defensive and appetitive reactions in picture processing.

Abstract

Emotional reactions are organized by underlying motivational states-defensive and appetitive-that have evolved to promote the survival of individuals and species. Affective responses were measured while participants viewed pictures with varied emotional and neutral content. Consistent with the motivational hypothesis, reports of the strongest emotional arousal, largest skin conductance responses, most pronounced cardiac deceleration, and greatest modulation of the startle reflex occurred when participants viewed pictures depicting threat, violent death, and erotica. Moreover, reflex modulation and conductance change varied with arousal, whereas facial patterns were content specific. The findings suggest that affective responses serve different functions-mobilization for action, attention, and social communication-and reflect the motivational system that is engaged, its intensity of activation, and the specific emotional context.

Emotional scenes and facial expressions elicit different psychophysiological responses

“…The response is potentiated when viewing slides with negative content, and reduced when viewing positive pictures (Vrana et al, 1988). In addition, measures of autonomic activity covary with the level of arousal or with the valence of the presented stimulus (Bradley et al, 2001). The typical pattern of defensive motivation is an initial heart rate deceleration which indicates orientation towards a meaningful stimulus (Graham, 1997;Graham and Clifton, 1966).…”

“…A significant rise of the skin conductance level can be found for both positive and negative stimuli when compared to neutral ones (e.g., Azevedo et al, 2005;Bradley et al, 2001Bradley et al, , 2005.…”

“…The EMG response was baseline-corrected by subtracting data from a 100 ms baseline preceding the trial in 100 ms steps, and an average for the first three seconds of each trial was calculated. 4 For the heart rate response, R-spikes were marked in the EKG and inter-beat-intervals were calculated and transformed into beats per minute, in one second bins (see Bradley et al, 2001;Gatchel and Lang, 1974;Hodes et al, 1985). To determine initial heart rate deceleration as the orienting response (Bradley et al, 2001), changed scores were calculated with mean beats per minute for the first three seconds of picture presentation relative to a three second baseline period directly preceding stimulus onset.…”

“…Within this framework, emotional reactions to external cues are modulated by two dimensionally organized stimulus features: valence and arousal. Judgments of valence, i.e., pleasure or displeasure, relate to the active motivational system and judgments of arousal relate to the intensity of motivational activation (Bradley et al, 2001). Pictures of emotional scenes (Lang, 1995) and emotional facial expressions (Russell and Bullock, 1985) can be described by ratings on these two dimensions.…”

“…Pictures of emotional scenes (Lang, 1995) and emotional facial expressions (Russell and Bullock, 1985) can be described by ratings on these two dimensions. Evidence for this motivational theory of emotion comes from an impressive number of studies using the picture viewing paradigm to elicit approach and avoidance motivation (Bradley et al, 2001;Lang et al, 1997).…”