Faces and voices, in isolation, prompt consistent social evaluations. However, most human interactions involve both seeing and talking with another person. Our main goal was to investigate how facial and vocal information are combined to reach an integrated person impression. In Study 1, we asked participants to rate faces and voices separately for perceived trustworthiness, attractiveness, and dominance. Most previous studies relied on stimuli in which extra-vocal information (e.g., verbal content, prosody) may have confounded voice-based effects; to prevent these unwanted influences, we used brief, neutral vowel sounds. Voices, like faces, led to the formation of highly reliable impressions. Voice trustworthiness correlated with voice attractiveness, mirroring the relation between face trustworthiness and attractiveness, but did not correlate with voice dominance. Inconsistent with the possibility that face and voice evaluations are indicative of real character traits, we found no positive correlations between judgments of trustworthiness or dominance based on faces and the same judgments based on voices (there was also no correlation between face attractiveness and voice attractiveness). In Study 2, we asked participants to evaluate male targets after seeing their faces and hearing their voices. Faces and voices contributed equally to judgments of trustworthiness and combined to produce a significant interaction effect. For attractiveness, faces were given more weight than voices, possibly due to the predominantly visual character of the attractiveness concept (there was no interaction effect). For dominance, the reverse pattern was true, with voices having a larger effect than faces on final judgments. In this case the auditory cues may be perceived to be more reliable because of the strong links between voice pitch, masculinity, and dominance.

In the last 15 years, increasing numbers of individuals have self-referred to research laboratories in the belief that they experience severe everyday difficulties with face recognition. The condition “developmental prosopagnosia” (DP) is typically diagnosed when impairment is identified on at least two objective face-processing tests, usually involving assessments of face perception, unfamiliar face memory, and famous face recognition. While existing evidence suggests that some individuals may have a mnemonic form of prosopagnosia, it is also possible that other subtypes exist. The current study assessed 165 adults who believe they experience DP, and 38% of the sample were impaired on at least two of the tests outlined above. While statistical dissociations between face perception and face memory were only observed in four cases, a further 25% of the sample displayed dissociations between impaired famous face recognition and intact short-term unfamiliar face memory and face perception. We discuss whether this pattern of findings reflects (a) limitations within dominant diagnostic tests and protocols, (b) a less severe form of DP, or (c) a currently unrecognized but prevalent form of the condition that affects long-term face memory, familiar face recognition or semantic processing.

Facial emotion perception plays a key role in interpersonal communication and is a precursor for a variety of socio-cognitive abilities. One brain region thought to support emotion perception is the inferior frontal cortex (IFC). The current study aimed to examine whether modulating neural activity in the IFC using high frequency transcranial random noise stimulation (tRNS) could enhance emotion perception abilities. In Experiment 1, participants received either tRNS to IFC or sham stimulation prior to completing facial emotion and identity perception tasks. Those receiving tRNS significantly outperformed those receiving sham stimulation on facial emotion, but not identity, perception tasks. In Experiment 2, we examined whether baseline performance interacted with the effects of stimulation. Participants completed a facial emotion and identity discrimination task prior to and following tRNS to either IFC or an active control region (area V5/MT). Baseline performance was a significant predictor of emotion discrimination performance change following tRNS to IFC. This effect was not observed for tRNS targeted at V5/MT or for identity discrimination. Overall, the findings implicate the IFC in emotion processing and demonstrate that tRNS may be a useful tool to modulate emotion perception when accounting for individual differences in factors such as baseline task performance.

The sense of agency is defined as one's sense of control over one's actions and their consequences. A recent theory, the control-based response selection framework (Karsh and Eitam, Motivation from control: a response selection framework. The sense of agency, Oxford University Press, New York, 2015a), suggests that actions associated with a high sense of agency are intrinsically rewarding and thus motivate response selection. Previous studies support this theory by demonstrating that factors impacting on sense of agency (e.g. probability of an outcome following an action) also motivate selection of actions. Here we report a novel test of the control-based response selection framework in the domain of action-outcome contingency. The contingency between actions and their outcome has previously been demonstrated to impact the sense of agency, but its impact on the motivation to perform actions has not yet been examined. Participants were asked to press one of four buttons as randomly as possible. Each of the buttons was assigned a different probability of causing an outcome when pressed. Additionally, a contingency manipulation was employed where the probability of an outcome occurring in the absence of a button press was also varied in blocks throughout the experiment. Results demonstrated a significant influence of contingency on response speed, and a significant effect of probability on response selection, consistent with predictions from the control-based response selection framework. Furthermore, some evidence was observed for a positive correlation between influence of contingency and autistic traits, with individuals with higher autistic traits showing a greater influence of contingency on reaction times. The current findings support the idea that actions associated with an increased sense of agency are intrinsically rewarding, and identify how individual differences may impact on this process.

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