Self-face enhances processing of immediately preceding invisible faces

Me, myself and you: How self-consciousness influences time perception

Several investigations have shown that the processing of self-relevant information differs from processing objective information. The present study aimed to investigate the effect of social stimuli on subjective time processing. Here, social stimuli are images of an unknown male and female person and an image of participants' self. Forty university students were tested with a time reproduction task in which they were asked to reproduce the duration of the stimulus previously presented. Images of others or themselves were used to mark the temporal intervals. Participants also performed questionnaires to evaluate the level of anxiety and depression as well as self-consciousness. A generalised linear mixed-effects model approach was adopted. Results showed that male participants with higher Private Self-Consciousness scores showed higher time perception accuracy than females. Also, female participants reported higher scores for the Public Self-Consciousness subscale than male participants. The findings are discussed in terms of social context models of how attention is solicited and arousal is generated by social stimuli, highlighting the effect of social context on subjective perception of time.

Are covered faces eye-catching for us? The impact of masks on attentional processing of self and other faces during the COVID-19 pandemic

During the COVID-19 pandemic, we have been confronted with faces covered by surgical-like masks. This raises a question about how our brains process this kind of visual information. Thus, the aims of the current study were twofold: (1) to investigate the role of attention in the processing of different types of faces with masks, and (2) to test whether such partial information about faces is treated similarly to fully visible faces. Participants were tasked with the simple detection of self-, close-other's, and unknown faces with and without a mask; this task relies on attentional processes. Event-related potential (ERP) findings revealed a similar impact of surgical-like masks for all faces: the amplitudes of early (P100) and late (P300, LPP) attention-related components were higher for faces with masks than for fully visible faces. Amplitudes of N170 were similar for covered and fully visible faces, and sources of brain activity were located in the fusiform gyri in both cases. Linear Discriminant Analysis (LDA) revealed that irrespective of whether the algorithm was trained to discriminate three types of faces either with or without masks, it was able to effectively discriminate faces that were not presented in the training phase.

Unconscious social relation threats: Invisible boss face biases attention

Threatening stimuli as a kind of salient information often guide attentional orienting. Besides physically threatening stimuli, social threats can also strongly bias attention, even in the absence of conscious awareness. However, the available evidence mainly came from studies on an emotional face. It is unclear whether social relation threats, such as a boss face without emotional expressions, can also direct attentional orienting unconsciously. This study aimed to reveal the extent to which the attentional system has developed to process threatening stimuli by exploring whether invisible social relation threats unconsciously biased attention. We asked graduate and undergraduate students to perform a modified Posner's cue-target task, in which the probe was preceded by a pair of competitive face cues (an advisor's face and another faculty member's face), rendered invisible through continuous flash suppression. Experiment 1a's results showed that the advisor's face reflexively oriented graduate students' spatial attention, which was significantly correlated with subjective social threat evaluation. However, Experiment 1b showed that an invisible advisor's face did not induce the same effect in undergraduate students, as they reported significantly fewer threats from their advisors than graduates. To ensure the robustness of this new effect, we preregistered a replicate study and successfully replicated the above results in Experiments 2a and 2b. Our findings provide evidence for the existence of an attentional orienting bias toward invisible social relation threats. These results suggest that the attentional system evolved to promote the exploration of our visual environment for threatening social relation signals.

Self-face and emotional faces-are they alike?

The image of one’s own face is a particularly distinctive feature of the self. The self-face differs from other faces not only in respect of its familiarity but also in respect of its subjective emotional significance and saliency. The current study aimed at elucidating similarities/dissimilarities between processing of one’s own face and emotional faces: happy faces (based on the self-positive bias) and fearful faces (because of their high perceptual saliency, a feature shared with self-face). Electroencephalogram data were collected in the group of 30 participants who performed a simple detection task. Event-related potential analyses indicated significantly increased P3 and late positive potential amplitudes to the self-face in comparison to all other faces: fearful, happy and neutral. Permutation tests confirmed the differences between the self-face and all three types of other faces for numerous electrode sites and in broad time windows. Representational similarity analysis, in turn, revealed distinct processing of the self-face and did not provide any evidence in favour of similarities between the self-face and emotional (either negative or positive) faces. These findings strongly suggest that the self-face processing do not resemble those of emotional faces, thus implying that prioritized self-referential processing is driven by the subjective relevance of one’s own face.

Happy you, happy me: expressive changes on a stranger's voice recruit faster implicit processes than self-produced expressions

In social interactions, people have to pay attention both to the ‘what’ and ‘who’. In particular, expressive changes heard on speech signals have to be integrated with speaker identity, differentiating e.g. self- and other-produced signals. While previous research has shown that self-related visual information processing is facilitated compared to non-self stimuli, evidence in the auditory modality remains mixed. Here, we compared electroencephalography (EEG) responses to expressive changes in sequence of self- or other-produced speech sounds using a mismatch negativity (MMN) passive oddball paradigm. Critically, to control for speaker differences, we used programmable acoustic transformations to create voice deviants that differed from standards in exactly the same manner, making EEG responses to such deviations comparable between sequences. Our results indicate that expressive changes on a stranger’s voice are highly prioritized in auditory processing compared to identical changes on the self-voice. Other-voice deviants generate earlier MMN onset responses and involve stronger cortical activations in a left motor and somatosensory network suggestive of an increased recruitment of resources for less internally predictable, and therefore perhaps more socially relevant, signals.

Conscious awareness of self-relevant information is necessary for an incidental self-memory advantage

Co-presenting an item with self-relevant vs. other-relevant information under a non-self-referential encoding context can produce a memory advantage. The present study examined the relative contributions of conscious vs. unconscious processing of self-cues to this incidental self-memory advantage. During encoding, the participant's own or another person's name was presented supraliminally or subliminally prior to the presentation of each target word. Consistent across two experiments, we found better memory for words preceded by the own name vs. another name but only when the names were presented supraliminally. The masked priming effect produced by the own name in Experiment 2 suggests that the absence of a self-memory advantage following subliminal name presentation was unlikely due to subliminal self-processing being too weak. Our findings suggest that conscious awareness of self-cues is necessary for an incidental self-memory advantage. Potential qualitative differences between conscious vs. unconscious self-processing mediating the impact of self on memory are discussed.

Looking at My Own Face: Visual Processing Strategies in Self-Other Face Recognition

We live in an age of ‘selfies.’ Yet, how we look at our own faces has seldom been systematically investigated. In this study we test if the visual processing of the highly familiar self-face is different from other faces, using psychophysics and eye-tracking. This paradigm also enabled us to test the association between the psychophysical properties of self-face representation and visual processing strategies involved in self-face recognition. Thirty-three adults performed a self-face recognition task from a series of self-other face morphs with simultaneous eye-tracking. Participants were found to look longer at the lower part of the face for self-face compared to other-face. Participants with a more distinct self-face representation, as indexed by a steeper slope of the psychometric response curve for self-face recognition, were found to look longer at upper part of the faces identified as ‘self’ vs. those identified as ‘other’. This result indicates that self-face representation can influence where we look when we process our own vs. others’ faces. We also investigated the association of autism-related traits with self-face processing metrics since autism has previously been associated with atypical self-processing. The study did not find any self-face specific association with autistic traits, suggesting that autism-related features may be related to self-processing in a domain specific manner.

Cannot avert the eyes: reduced attentional blink toward others' emotional expressions in empathic people

Empathy is one of the core components of social interaction. Although current models of empathy emphasize the role of attention, few studies have directly examined the relationship between attentional processes and individual differences in empathy. This study hypothesized that empathic people would process emotional expressions more efficiently and automatically compared to less empathic people. Crucially, such a processing advantage should be present only for faces of others compared to one's own face. To test this hypothesis, 100 healthy participants varying in their self-reported empathy levels underwent an attentional blink task that tested preferential attentional processing. Results showed a diminished attentional blink effect for sad faces of others in the high-empathy group. Additionally, performance differences in the task were related to both trait empathy and daily prosocial behavior. Overall, our results show that emotional stimuli preferentially capture the attention of empathic people, leading to automatic processing.

Comparison of oxyhemoglobin and deoxyhemoglobin signal reliability with and without global mean removal for digit manipulation motor tasks

Functional near-infrared spectroscopy (fNIRS) could be well suited for clinical use, such as measuring neural activity before and after treatment; however, reliability and specificity of fNIRS signals must be ensured so that differences can be attributed to the intervention. This study compared the test-retest and longitudinal reliability of oxyhemoglobin and deoxyhemoglobin signals before and after spatial filtering. In the test-retest experiment, 14 participants were scanned on 2 days while performing four right-handed digit-manipulation tasks. Group results revealed greater test-retest reliability for oxyhemoglobin than deoxyhemoglobin signals and greater spatial specificity for the deoxyhemoglobin signals. To further characterize reliability, a longitudinal experiment was conducted in which two participants repeated the same motor tasks for 10 days. Beta values from the two tasks with the lowest and highest test-retest reliability, respectively, in the spatially filtered deoxyhemoglobin signal are reported as representative findings. Both test-retest and longitudinal methods confirmed that task and signal type influence reliability. Oxyhemoglobin signals were more reliable overall than deoxyhemoglobin, and removal of the global mean reduced reliability of both signals. Findings are consistent with the suggestion that systemic components most prevalent in the oxyhemoglobin signal may inflate reliability relative to the deoxyhemoglobin signal, which is less influenced by systemic factors.

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.

Fluctuations of Attentional Networks and Default Mode Network during the Resting State Reflect Variations in Cognitive States: Evidence from a Novel Resting-state Experience Sampling Method

Neuroimaging studies have revealed the recruitment of a range of neural networks during the resting state, which might reflect a variety of cognitive experiences and processes occurring in an individual's mind. In this study, we focused on the default mode network (DMN) and attentional networks and investigated their association with distinct mental states when participants are not performing an explicit task. To investigate the range of possible cognitive experiences more directly, this study proposes a novel method of resting-state fMRI experience sampling, informed by a phenomenological investigation of the fluctuation of mental states during the resting state. We hypothesized that DMN activity would increase as a function of internal mentation and that the activity of dorsal and ventral networks would indicate states of top–down versus bottom–up attention at rest. Results showed that dorsal attention network activity fluctuated as a function of subjective reports of attentional control, providing evidence that activity of this network reflects the perceived recruitment of controlled attentional processes during spontaneous cognition. Activity of the DMN increased when participants reported to be in a subjective state of internal mentation, but not when they reported to be in a state of perception. This study provides direct evidence for a link between fluctuations of resting-state neural activity and fluctuations in specific cognitive processes.

Amygdala and auditory cortex exhibit distinct sensitivity to relevant acoustic features of auditory emotions

Discriminating between auditory signals of different affective value is critical to successful social interaction. It is commonly held that acoustic decoding of such signals occurs in the auditory system, whereas affective decoding occurs in the amygdala. However, given that the amygdala receives direct subcortical projections that bypass the auditory cortex, it is possible that some acoustic decoding occurs in the amygdala as well, when the acoustic features are relevant for affective discrimination. We tested this hypothesis by combining functional neuroimaging with the neurophysiological phenomena of repetition suppression (RS) and repetition enhancement (RE) in human listeners. Our results show that both amygdala and auditory cortex responded differentially to physical voice features, suggesting that the amygdala and auditory cortex decode the affective quality of the voice not only by processing the emotional content from previously processed acoustic features, but also by processing the acoustic features themselves, when these are relevant to the identification of the voice's affective value. Specifically, we found that the auditory cortex is sensitive to spectral high-frequency voice cues when discriminating vocal anger from vocal fear and joy, whereas the amygdala is sensitive to vocal pitch when discriminating between negative vocal emotions (i.e., anger and fear). Vocal pitch is an instantaneously recognized voice feature, which is potentially transferred to the amygdala by direct subcortical projections. These results together provide evidence that, besides the auditory cortex, the amygdala too processes acoustic information, when this is relevant to the discrimination of auditory emotions.

Withholding response to self-face is faster than to other-face

Self-face advantage refers to adults' response to self-face is faster than that to other-face. A stop-signal task was used to explore how self-face advantage interacted with response inhibition. The results showed that reaction times of self-face were faster than that of other-face not in the go task but in the stop response trials. The novelty of the finding was that self-face has shorter stop-signal reaction time compared to other-face in the successful inhibition trials. These results indicated the processing mechanism of self-face may be characterized by a strong response tendency and a corresponding strong inhibition control.

The free-energy self: a predictive coding account of self-recognition

Recognising and representing one's self as distinct from others is a fundamental component of self-awareness. However, current theories of self-recognition are not embedded within global theories of cortical function and therefore fail to provide a compelling explanation of how the self is processed. We present a theoretical account of the neural and computational basis of self-recognition that is embedded within the free-energy account of cortical function. In this account one's body is processed in a Bayesian manner as the most likely to be "me". Such probabilistic representation arises through the integration of information from hierarchically organised unimodal systems in higher-level multimodal areas. This information takes the form of bottom-up "surprise" signals from unimodal sensory systems that are explained away by top-down processes that minimise the level of surprise across the brain. We present evidence that this theoretical perspective may account for the findings of psychological and neuroimaging investigations into self-recognition and particularly evidence that representations of the self are malleable, rather than fixed as previous accounts of self-recognition might suggest.

Exposure to subliminal arousing stimuli induces robust activation in the amygdala, hippocampus, anterior cingulate, insular cortex and primary visual cortex: a systematic meta-analysis of fMRI studies

Functional Magnetic Resonance Imaging (fMRI) demonstrates that the subliminal presentation of arousing stimuli can activate subcortical brain regions independently of consciousness-generating top-down cortical modulation loops. Delineating these processes may elucidate mechanisms for arousal, aberration in which may underlie some psychiatric conditions. Here we are the first to review and discuss four Activation Likelihood Estimation (ALE) meta-analyses of fMRI studies using subliminal paradigms. We find a maximum of 9 out of 12 studies using subliminal presentation of faces contributing to activation of the amygdala, and also a significantly high number of studies reporting activation in the bilateral anterior cingulate, bilateral insular cortex, hippocampus and primary visual cortex. Subliminal faces are the strongest modality, whereas lexical stimuli are the weakest. Meta-analyses independent of studies using Regions of Interest (ROI) revealed no biasing effect. Core neuronal arousal in the brain, which may be at first independent of conscious processing, potentially involves a network incorporating primary visual areas, somatosensory, implicit memory and conflict monitoring regions. These data could provide candidate brain regions for the study of psychiatric disorders associated with aberrant automatic emotional processing.