Passively viewing negatively valenced baby faces attenuates left amygdala activity in healthy females scoring high on ‘Harm Avoidance’

Abstract

The amygdalae play an important role in the evaluation and processing of emotionally salient visual stimuli. However, individual differences in personality traits, such as Harm Avoidance (HA), have been reported to influence emotional amygdalae responses. To trigger strong approach and withdrawal-related emotions in 'never depressed' young female subjects under fMRI, we presented them with blocks of happy 'healthy' baby faces and baby faces disfigured by severe dermatological conditions and we integrated the temperament dimension HA into our analysis. No other instructions were given than to watch the images attentively. Only in withdrawal-related emotional experience, we observed a negative correlation between HA and left amygdala activity, suggesting that during passive viewing females scoring higher on HA 'avoid' images with highly aversive content. When investigating the amygdala's emotional role in passive viewing paradigms, personality features such as HA should be taken into account.Keywords: Approach and withdrawal-related emotions, Amygdala, fMRI, Healthy Females, Harm Avoidance 3 A number of studies, using a variety of task instructions, have investigated the role of the amygdalae in the evaluation of social cues and the processing of emotional stimuli such as 'emotional' facial expressions and gender, age, and differences in personality features have been reported to influence amygdala activity [1,40]. When introducing individual information such as personality characteristics as covariate in the analysis of 'emotional' fMRI paradigms in healthy individuals, predominantly left sided amygdala activation has been reported [11]. Increased (left-sided) amygdala activation has also been reported in 'anxiety-prone' individuals (non-clinical subjects displaying high levels of anxiety-related traits) during the processing of emotion [5]. In addition, 'emotional' brain imaging research has already demonstrated the importance of the temperament dimension Harm Avoidance (HA) [29], extracted out of the Temperament and Character Inventory (TCI [12]). High scorers on HA show a tendency to respond more intensely to aversive stimuli compared to low HA scorers [24]. Subjects who score high on HA describe themselves as fearful, pessimistic, shy, and fatigued, and they have a tendency to respond intensely to signals of aversive stimuli, whereas those scoring low on HA characterize themselves as optimistic and outgoing risk-takers [12]. Amygdala 'hyperactivity' in affective disorders is commonly found and in depressed patients increases in amygdala activity have been reported to be lateralized to the left [14] (however, see [37]).Paying special attention to the salient nature of the mood inducing stimuli, in this study we reinvestigate the hypothesis that individual scores on the temperament dimension HA might influence the observation of predominantly left-sided amygdala processing. We have used an adapted paradigm with baby faces as visual 'emotional' stimuli to induce approach and withdrawal-related emotions. We 4 inc...

Does the amygdala response correlate with the personality trait ‘harm avoidance’ while evaluating emotional stimuli explicitly?

“…This study revealed an increased left lateralized amygdala response to the negative stimuli in the high HA participants while no lateralization of the amygdalae response was observed in the low and average HA participants. Contrary to this, the [29] study revealed a negative correlation between the left amygdala activation and HA during the sustained processing of negative stimuli, probably due to an increased tendency in the high HA participants to shift attention away from the negative stimuli in an attempt to control the induced emotional reaction.…”

“…These pictures were similar to the stimuli used in our previous studies [29,30]. The pictures for the positive stimuli were collected from family photos from staff members and from the Internet, while those for the negative stimuli originated from the dermatological literature.…”

“…In a previous study [29] when trying to relate emotion induced amygdalae activity to the personality trait HA beyond the attentional modulation, the participants were instructed to simply observe attentively positive, negative and neutral stimuli without, performing any emotional or cognitive task. This study was based on an earlier study [30] in which differences in the lateralization of the amygdalae responses to affective stimuli were studied in low, average and high HA females.…”

Shyness and the first 100 ms of emotional face processing

“…Previous fMRI research has reported a reduction in amygdala activity associated with aversive photos of baby faces (i.e., baby faces disfigured by dermatological conditions) in individuals high in harm avoidance, a personality construct characterized as a general inclination to respond intensely to aversive stimuli, including shyness behavior (Baeken et al, 2010). Although it is difficult to compare across ERP and fMRI methodologies, the high temporal resolution of ERPs and our current findings may indicate that such reductions in amygdala activity to aversive or stressful stimuli as a function of personality may begin as early as 80 ms post-stimulus onset in extrastriate visual cortex along the ventral visual pathways that generate P1 activity (Hillyard & Anllo-Vento, 1998).…”

“…For example, a recent study reported that harm avoidance, a personality construct characterized as a general inclination to respond intensely to aversive stimuli, was related to a reduction of amygdala activity in response to aversive photos of baby faces (i.e., baby faces disfigured by dermatological conditions) but not to photos of happy baby faces (Baeken et al, 2010). Other research found trait disgust (i.e., disgust sensitivity) to be related to reductions of amygdala activity during imagined visualizations of previously presented photos that were shown to induce disgust (Schienle, Schäfer, & Vaitl, 2008), whereas such reductions were not reported for happy photos.…”