Direct gaze of photographs of female nudes influences startle in men

Self-Resemblance Modulates Processing of Socio-Emotional Pictures in a Context-Sensitive Manner

Abstract. Relevance of emotional information varies with self-involvement. The current study was undertaken to test whether subtle facial self-resemblance is sufficient to affect attentional and affective processing of complex socio-emotional pictures. Faces digitally manipulated to resemble the participants’ (final sample: N = 21) own versus unfamiliar control faces (form and color morphs) were presented in pictures of emotionally evocative social interactions, that is, threat versus sex scenes. At stimulus onset asynchronies (SOAs) of either 300 ms or 3,000 ms after picture onset, startle responses were elicited by acoustic white noise bursts (50 ms, 105 dB), and recorded at the orbicularis oculi via electromyography (EMG). The majority of participants remained unaware of the morphing manipulation, and awareness did not affect the principal results. As indexed by inhibition of startle at short lead intervals and by picture-evoked heart rate deceleration, facial self-resemblance modulates effects of motivational salience in a context-sensitive way, increasing prepulse inhibition with threat-related, but not erotic cues. Overall, the present study suggests that visual cues of general motivational significance and of self-relevance are integrated in a fast, presumably automatic manner.

Affective Eye Contact: An Integrative Review

In recent years, many studies have shown that perceiving other individuals' direct gaze has robust effects on various attentional and cognitive processes. However, considerably less attention has been devoted to investigating the affective effects triggered by eye contact. This article reviews research concerning the effects of others' gaze direction on observers' affective responses. The review focuses on studies in which affective reactions have been investigated in well-controlled laboratory experiments, and in which contextual factors possibly influencing perceivers' affects have been controlled. Two important themes emerged from this review. First, explicit affective evaluations of seeing another's direct versus averted gaze have resulted in rather inconsistent findings; some studies report more positive subjective feelings to direct compared to averted gaze, whereas others report the opposite pattern. These contradictory findings may be related, for example, to differences between studies in terms of the capability of direct-gaze stimuli to elicit feelings of self-involvement. Second, studies relying on various implicit measures have reported more consistent results; they indicate that direct gaze increases affective arousal, and more importantly, that eye contact automatically evokes a positively valenced affective reaction. Based on the review, possible psychological mechanisms for the positive affective reactions elicited by eye contact are described.

Startling similarity: Effects of facial self-resemblance and familiarity on the processing of emotional faces

Facial self-resemblance has been associated with positive emotional evaluations, but this effect may be biased by self-face familiarity. Here we report two experiments utilizing startle modulation to investigate how the processing of facial expressions of emotion is affected by subtle resemblance to the self as well as to familiar faces. Participants of the first experiment (I) (N = 39) were presented with morphed faces showing happy, neutral, and fearful expressions which were manipulated to resemble either their own or unknown faces. At SOAs of either 300 ms or 3500–4500 ms after picture onset, startle responses were elicited by binaural bursts of white noise (50 ms, 105 dB), and recorded at the orbicularis oculi via EMG. Manual reaction time was measured in a simple emotion discrimination paradigm. Pictures preceding noise bursts by short SOA inhibited startle (prepulse inhibition, PPI). Both affective modulation and PPI of startle in response to emotional faces was altered by physical similarity to the self. As indexed both by relative facilitation of startle and faster manual responses, self-resemblance apparently induced deeper processing of facial affect, particularly in happy faces. Experiment II (N = 54) produced similar findings using morphs of famous faces, yet showed no impact of mere familiarity on PPI effects (or response time, either). The results are discussed with respect to differential (presumably pre-attentive) effects of self-specific vs. familiar information in face processing.

In Your Face: Startle to Emotional Facial Expressions Depends on Face Direction

Although faces are often included in the broad category of emotional visual stimuli, the affective impact of different facial expressions is not well documented. The present experiment investigated startle electromyographic responses to pictures of neutral, happy, angry, and fearful facial expressions, with a frontal face direction (directed) and at a 45° angle to the left (averted). Results showed that emotional facial expressions interact with face direction to produce startle potentiation: Greater responses were found for angry expressions, compared with fear and neutrality, with directed faces. When faces were averted, fear and neutrality produced larger responses compared with anger and happiness. These results are in line with the notion that startle is potentiated to stimuli signaling threat. That is, a forward directed angry face may signal a threat toward the observer, and a fearful face directed to the side may signal a possible threat in the environment.

Effect of facial self-resemblance on the startle response and subjective ratings of erotic stimuli in heterosexual men

Cues of kinship are predicted to increase prosocial behavior due to the benefits of inclusive fitness, but to decrease approach motivation due to the potential costs of inbreeding. Previous studies have shown that facial resemblance, a putative cue of kinship, increases prosocial behavior. However, the effects of facial resemblance on mating preferences are equivocal, with some studies finding that facial resemblance decreases sexual attractiveness ratings, while other studies show that individuals choose mates partly on the basis of similarity. To further investigate this issue, a psychophysiological measure of affective processing, the startle response, was used in this study, assuming that differences in approach motivation to erotic pictures will modulate startle. Male volunteers (n = 30) viewed 30 pictures of erotic female nudes while startle eyeblink responses were elicited by acoustic noise probes. The female nude pictures were digitally altered so that the face either resembled the male participant or another participant, or were not altered. Non-nude neutral pictures were also included. Importantly, the digital alteration was undetected by the participants. Erotic pictures were rated as being pleasant and clearly reduced startle eyeblink magnitude as compared to neutral pictures. Participants showed greater startle inhibition to self-resembling than to other-resembling or non-manipulated female nude pictures, but subjective pleasure and arousal ratings did not differ among the three erotic picture categories. Our data suggest that visual facial resemblance of opposite-sex nudes increases approach motivation in men, and that this effect was not due to their conscious evaluation of the erotic stimuli.

Effects of stress on human mating preferences: stressed individuals prefer dissimilar mates

Although humans usually prefer mates that resemble themselves, mating preferences can vary with context. Stress has been shown to alter mating preferences in animals, but the effects of stress on human mating preferences are unknown. Here, we investigated whether stress alters men's preference for self-resembling mates. Participants first underwent a cold-pressor test (stress induction) or a control procedure. Then, participants viewed either neutral pictures or pictures of erotic female nudes whose facial characteristics were computer-modified to resemble either the participant or another participant, or were not modified, while startle eyeblink responses were elicited by noise probes. Erotic pictures were rated as being pleasant, and reduced startle magnitude compared with neutral pictures. In the control group, startle magnitude was smaller during foreground presentation of photographs of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to self-resembling mates. In the stress group, startle magnitude was larger during foreground presentation of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to dissimilar mates. Our findings show that stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates.