Unfamiliar Faces Research Articles

Perceptual Narrowing in Face Processing: Reviewing the Factors Influencing its Onset and Offset

AbstractAn infant's face‐ and speech‐processing system develops during the first year from broad and non‐specific to becoming a system that is tuned to the faces and languages to which they are most exposed. This phenomenon is called perceptual narrowing. Before 9 months of age, infants are capable of discriminating and recognizing individuals from any type of race/species faces. However, with increased exposure to own‐race and own‐species faces and lack of exposure to other types of faces, by 9 months of age, they have improved their ability to discriminate own‐race faces, while they show increased difficulty in the discrimination of faces from other races and species. According to the literature, we can conclude that, by 12 months of age, most human perceptual systems have become perceptually tuned and adult‐like; however, this is not true. In the following sections, we will argue that perceptual narrowing for faces occurs during the same developmental period as it does for language, and that it can be prevented or modulated with sufficient exposure to unfamiliar sounds or face types. We conclude that narrowing has been designed by natural selection to tailor an individual's cognition to their local social context. It might occur for every domain pertaining to social communication—from speech processing to emotion or gesture perception—in a process that gradually adapts the infant to their native social group.

EEG-FRM: a neural network based familiar and unfamiliar face EEG recognition method.

Recognizing familiar faces holds great value in various fields such as medicine, criminal investigation, and lie detection. In this paper, we designed a Complex Trial Protocol-based familiar and unfamiliar face recognition experiment that using self-face information, and collected EEG data from 147 subjects. A novel neural network-based method, the EEG-based Face Recognition Model (EEG-FRM), is proposed in this paper for cross-subject familiar/unfamiliar face recognition, which combines a multi-scale convolutional classification network with the maximum probability mechanism to realize individual face recognition. The multi-scale convolutional neural network extracts temporal information and spatial features from the EEG data, the attention module and supervised contrastive learning module are employed to promote the classification performance. Experimental results on the dataset reveal that familiar face stimuli could evoke significant P300 responses, mainly concentrated in the parietal lobe and nearby regions. Our proposed model achieved impressive results, with a balanced accuracy of 85.64%, a true positive rate of 73.23%, and a false positive rate of 1.96% on the collected dataset, outperforming other compared methods. The experimental results demonstrate the effectiveness and superiority of our proposed model.

Familiarity Is Key: Exploring the Effect of Familiarity on the Face-Voice Correlation.

Recent research has examined the extent to which face and voice processing are associated by virtue of the fact that both tap into a common person perception system. However, existing findings do not yet fully clarify the role of familiarity in this association. Given this, two experiments are presented that examine face-voice correlations for unfamiliar stimuli (Experiment 1) and for familiar stimuli (Experiment 2). With care being taken to use tasks that avoid floor and ceiling effects and that use realistic speech-based voice clips, the results suggested a significant positive but small-sized correlation between face and voice processing when recognizing unfamiliar individuals. In contrast, the correlation when matching familiar individuals was significant and positive, but much larger. The results supported the existing literature suggesting that face and voice processing are aligned as constituents of an overarching person perception system. However, the difference in magnitude of their association here reinforced the view that familiar and unfamiliar stimuli are processed in different ways. This likely reflects the importance of a pre-existing mental representation and cross-talk within the neural architectures when processing familiar faces and voices, and yet the reliance on more superficial stimulus-based and modality-specific analysis when processing unfamiliar faces and voices.

Holistic Processing of Recognition Memory for Face Identity: Evidence from a Face Morphing Paradigm

AbstractHolistic face processing refers to a tendency to see face parts as a whole. This study examined whether and how holistic processing affects recognition memory for face identity in a learned/novel morphing continuum. In the study phase of each experiment reported here, adult participants were asked to memorize (i.e., learn) a set of unfamiliar face images by viewing them once or twice. In the test phase, the participants were presented with face images morphed from learned and novel ones and were asked to report whether they viewed the face in the study phase. In Experiment 1, we demonstrated that our morphing paradigm can capture memory selectivity changes (i.e., recognition boundary and sensitivity) associated with learned face identity. In Experiment 2, we demonstrated that whole‐face presentations improved sensitivity to learned/novel face identity, but did not alter the recognition boundary between learned and novel face identity. These results support the view that holistic processing contributes to accurate face identification in recognition memory, even under minimal learning situations.

Восприятие естественной асимметричности знакомых и незнакомых лиц

Background. Despite the abundance of human face recognition models and research carried out in this area over the past half-century, there are still open questions about the uniqueness of the facial perception processes and about the oneness or difference of the mechanisms of perception of familiar and unfamiliar faces. Objective. Research into the mechanisms of perception of (a)symmetry of familiar and unfamiliar faces. Study Participants. 34 people participated in the study: 25 classmates (11 female and 14 male, Мage = 16, SD = 0,49) and 9 teachers (6 female and 3 male, Мage = 33, SD = 8,71). Methods. Methods of inversion and horizontal mirroring of face images were used to compare the mechanisms of perception of facial symmetry in familiar and unfamiliar faces. Mirroring allowed to change the face itself without violating its recognition and maintaining the overall degree of its (a)symmetry. The inversion impaired the perception of the facial configuration. Study participants assessed the degree of asymmetry in the images of familiar (photographs of classmates) and unfamiliar faces in four presentation conditions: original / mirrored faces presented upright / inverted. Results. The study results demonstrated that when presented upright, familiar mirrored faces are perceived as more asymmetrical than the original ones; no difference was revealed for unfamiliar faces. When inverting images, the ratings of the original and mirrored versions of the faces do not differ significantly for both familiar and unfamiliar faces. A small inversion effect was found in the ratings of original familiar faces: inverted familiar faces were rated as more asymmetrical than upright ones. Conclusions. The study results generally support the hypothesis that the mechanisms of perception of (a)symmetry in familiar and unfamiliar faces differ. Furthermore, there is reason to consider the assessment of a face (a)symmetry as involving not only configural, but also analytical mechanisms of its perception.

Does the relationship between the interviewer and interviewee matter in qualitative research?

The purpose of this viewpoint is to outline the relationship between the interviewer and interviewee in qualitative research, data collection and data quality. The argument draws upon qualitative research and publication among academicians and researchers, as well as the researcher’s observation. The relationship is an epic in qualitative and quantitative research and data collection. The relationship has positive and negative responses as well as advantages and disadvantages. Familiarity within the industry and respondents may make the data collection process more accessible, suitable and less time worthy, and money savings in collecting data set for the qualitative research. At the same time, unfamiliarity among the interviewer and interviewees may lead to the bias data from the interviewee and time-consuming. The researchers need to consider the relationship in future qualitative research and data quality for greater flexibility to attain research objectives. The viewpoint is valuable to those engaged in various aspects of qualitative research, data collection, and data evaluation either in a familiar or unfamiliar face.

Influence of visual acuity on monocular face perception and exploration: Evidence from gaze‐contingency

Aims/Purpose: The remarkable ability of the human brain to identify faces has traditionally been divided in the scientific literature into relative contribution of an analytical versus a holistic way of processing the visual stimuli. Although the “part‐by‐part” analysis allows identification, previous studies have proven that the ability to perceive all parts in a simultaneous fashion seems to be the key element of what makes observers experts at face identification. Here, we aim to better understand the impact of visual acuity (VA) on the holistic and analytical processing of the face.Methods: We performed face‐matching tasks of unfamiliar faces using a gaze‐contingency approach in 12 normally sighted adults. Three viewing conditions (full view, mask effect, window effect) were simulated while VA was artificially decreased using a blur technique to obtain a linear scale of VA from LogMar 1,3 to 0,3.Results: At the group level, response times and number of fixations in full view, mask effect and window effect remained well preserved at VA as low as LogMar 1,0. Around that level of VA, both time and number of fixations increased with decreasing VA and were higher in the mask condition than in the other conditions.Conclusions: Facial identification performances remain well preserved at low VA. Evolution has allowed the brain to identify faces even if pathologies affecting the visual pathways strongly limit VA. This probably derives from the holistic strategy for face identification and the involvement of brain areas specialized in high level visual processing.

No modulation effects of depressive traits on the self-face advantage

The self-face advantage (SFA) is reflected through a faster recognition of a self-face compared to other faces. It has been suggested that this effect is prompted by one's positive self-evaluations. However, it is unclear whether negative self-concepts (depressive traits) also affect the SFA. The present study explored this possibility using a visual-search task. In Experiment 1, participants with low and high depressive traits were asked to search for frontal view images of self and unfamiliar faces among arrays of unfamiliar faces. Regardless of group, participants were better and faster in searching for the own face compared to the unfamiliar face. Similar findings were observed in Experiment 2, but the participants were more accurate when searching for their happy self-face compared to their sad and neutral faces. These results suggest that SFA is not modulated by depressive traits (i.e., negative self-concepts) and that familiarity effects for the own face could be implicated as an underlying factor for an attentional prioritization of the own face.

Familiarity Processing through Faces and Names: Insights from Multivoxel Pattern Analysis.

The way our brain processes personal familiarity is still debatable. We used searchlight multivoxel pattern analysis (MVPA) to identify areas where local fMRI patterns could contribute to familiarity detection for both faces and name categories. Significantly, we identified cortical areas in frontal, temporal, cingulate, and insular areas, where it is possible to accurately cross-classify familiar stimuli from one category using a classifier trained with the stimulus from the other (i.e., abstract familiarity) based on local fMRI patterns. We also discovered several areas in the fusiform gyrus, frontal, and temporal regions-primarily lateralized to the right hemisphere-supporting the classification of familiar faces but failing to do so for names. Also, responses to familiar names (compared to unfamiliar names) consistently showed less activation strength than responses to familiar faces (compared to unfamiliar faces). The results evinced a set of abstract familiarity areas (independent of the stimulus type) and regions specifically related only to face familiarity, contributing to recognizing familiar individuals.

Neural mechanisms of face familiarity and learning in the human amygdala and hippocampus

Recognizing familiar faces and learning new faces play an important role in social cognition. However, the underlying neural computational mechanisms remain unclear. Here, we record from single neurons in the human amygdala and hippocampus and find a greater neuronal representational distance between pairs of familiar faces than unfamiliar faces, suggesting that neural representations for familiar faces are more distinct. Representational distance increases with exposures to the same identity, suggesting that neural face representations are sharpened with learning and familiarization. Furthermore, representational distance is positively correlated with visual dissimilarity between faces, and exposure to visually similar faces increases representational distance, thus sharpening neural representations. Finally, we construct a computational model that demonstrates an increase in the representational distance of artificial units with training. Together, our results suggest that the neuronal population geometry, quantified by the representational distance, encodes face familiarity, similarity, and learning, forming the basis of face recognition and memory.

Resistance of a short-term memory concealed information test with famous faces to countermeasures

The concealed information test (CIT) aims at identifying knowledge that a person wants to hide, by measuring physiological indices during the presentation of known versus unknown items. Recently, Lancry-Dayan et al. (Journal of Applied Research in Memory and Cognition, 7 (2), 291–302, 2018) proposed a new version of this test that included a short-term memory task to maximize differences between responses to items. Participants were asked to memorize four pictures of faces that included one face of an acquaintance. The authors observed that participants looked at the familiar face during the first second and then tended to avoid it. This specific orientation-avoidance pattern occurred even in participants instructed to conceal their familiarity with the known faces (in a spontaneous or a guided manner). In a first experiment, we reproduced Lancry-Dayan et al.’s (2018) study using photos of famous faces. The pattern found by Lancry-Dayan et al. was observed in participants asked to perform the memory task only, participants asked to conceal their familiarity with the famous faces, and participants of a countermeasure group. In a second experiment, we tested the robustness of Lancry-Dayan et al.'s countermeasure. We modified the instructions by emphasizing the oculomotor task or giving feedback. While between-group differences in gaze-pattern appeared after feedback was provided, classification analyses were still able to distinguish between familiar and unfamiliar faces accurately, which revealed the good resistance of this new CIT protocol to countermeasures.

Adaptation to Residential Care: Voices from New Zealand

This article explores the adaptation process of older adults in residential care facilities in New Zealand. Through a phenomenological approach, this study provides clarity on how older adults adjust in residential care despite losses and challenges. Qualitative data on 24 older adults, 6 residential care facilities, and 10 staff were collected. Utilising qualitative software the following were identified: loss, support, acceptance and meaningful support. Initially, the unfamiliar environment and faces, structured routines, lack of interaction, absence of familiar activities, and limited visits from family and friends increased residents’ feelings of loneliness with institutionalisation. In time, they adapted to the routines and came to accept the facilities as, if not “home,” then “like home.” Participation in activities and support from staff and family contributed to this process. Activities can facilitate adjustment by promoting social contact, providing meaning and helping residents to establish new identities. The participants’ stories revealed that, despite the challenges of relocation, they adapted well to the residential environment.

Atypical reliance on monocular visual pathway for face and word recognition in developmental dyslexia

Studies with individuals with developmental dyslexia (DD) have documented impaired perception of words and faces, both of which are domains of visual expertise for human adults. In this study, we examined a possible mechanism that might be associated with the impaired acquisition of visual expertise for words and faces in DD, namely, the atypical engagement of the monocular visual pathway. Participants with DD and typical readers (TR) judged whether a pair of sequentially presented unfamiliar faces or nonwords were the same or different, and the pair of stimuli were displayed in an eye-specific fashion using a stereoscope. Based on evidence of greater reliance on subcortical structures early in development, we predicted differences between the groups in the engagement of lower (monocular) versus higher (binocular) regions of the visual pathways. Whereas the TR group showed a monocular advantage for both stimulus types, the DD participants evinced a monocular advantage for faces and words that was much greater than that measured in the TRs. These findings indicate that the DD individuals have enhanced subcortical engagement and that this might arise from the failure to fine-tune cortical correlates mediating the discrimination of homogeneous exemplars in domains of expertise.

Your place or mine? The neural dynamics of personally familiar scene recognition suggests category independent familiarity encoding.

Recognizing a stimulus as familiar is an important capacity in our everyday life. Recent investigation of visual processes has led to important insights into the nature of the neural representations of familiarity for human faces. Still, little is known about how familiarity affects the neural dynamics of non-face stimulus processing. Here we report the results of an EEG study, examining the representational dynamics of personally familiar scenes. Participants viewed highly variable images of their own apartments and unfamiliar ones, as well as personally familiar and unfamiliar faces. Multivariate pattern analyses were used to examine the time course of differential processing of familiar and unfamiliar stimuli. Time-resolved classification revealed that familiarity is decodable from the EEG data similarly for scenes and faces. The temporal dynamics showed delayed onsets and peaks for scenes as compared to faces. Familiarity information, starting at 200ms, generalized across stimulus categories and led to a robust familiarity effect. In addition, familiarity enhanced category representations in early (250-300ms) and later (>400ms) processing stages. Our results extend previous face familiarity results to another stimulus category and suggest that familiarity as a construct can be understood as a general, stimulus-independent processing step during recognition.

Modeling naturalistic face processing in humans with deep convolutional neural networks.

Deep convolutional neural networks (DCNNs) trained for face identification can rival and even exceed human-level performance. The ways in which the internal face representations in DCNNs relate to human cognitive representations and brain activity are not well understood. Nearly all previous studies focused on static face image processing with rapid display times and ignored the processing of naturalistic, dynamic information. To address this gap, we developed the largest naturalistic dynamic face stimulus set in human neuroimaging research (700+ naturalistic video clips of unfamiliar faces). We used this naturalistic dataset to compare representational geometries estimated from DCNNs, behavioral responses, and brain responses. We found that DCNN representational geometries were consistent across architectures, cognitive representational geometries were consistent across raters in a behavioral arrangement task, and neural representational geometries in face areas were consistent across brains. Representational geometries in late, fully connected DCNN layers, which are optimized for individuation, were much more weakly correlated with cognitive and neural geometries than were geometries in late-intermediate layers. The late-intermediate face-DCNN layers successfully matched cognitive representational geometries, as measured with a behavioral arrangement task that primarily reflected categorical attributes, and correlated with neural representational geometries in known face-selective topographies. Our study suggests that current DCNNs successfully capture neural cognitive processes for categorical attributes of faces but less accurately capture individuation and dynamic features.

Intracerebral electrical stimulation of the face-selective right lateral fusiform gyrus transiently impairs face identity recognition

Neuroimaging and intracranial electrophysiological studies have consistently shown the largest and most consistent face-selective neural activity in the middle portion of the human right lateral fusiform gyrus (‘fusiform face area(s)’, FFA). Yet, direct evidence for the critical role of this region in face identity recognition (FIR) is still lacking. Here we report the first evidence of transient behavioral impairment of FIR during focal electrical stimulation of the right FFA. Upon stimulation of an electrode contact within this region, subject CJ, who shows typical FIR ability outside of stimulation, was transiently unable to point to pictures of famous faces among strangers and to match pictures of famous or unfamiliar faces presented simultaneously for their identity. Her performance at comparable tasks with other visual materials (written names, pictures of buildings) remained unaffected by stimulation at the same location. During right FFA stimulation, CJ consistently reported that simultaneously presented faces appeared as being the same identity, with little or no distortion of the spatial face configuration. Independent electrophysiological recordings showed the largest neural face-selective and face identity activity at the critical electrode contacts. Altogether, this extensive multimodal case report supports the causal role of the right FFA in FIR.

High familiar faces have both eye recognition and holistic processing advantages.

People recognize familiar faces better than unfamiliar faces. However, it remains unknown whether familiarity affects part-based and/or holistic processing. Wang et al., Frontiers in Psychology, 6, 559 (2015), Vision Research, 157, 89-96 (2019) found both enhanced part-based and holistic processing in eye relative to mouth regions (i.e., in a region-selective manner) for own-race and own-species faces, i.e., faces with more experience. Here, we examined the role of face familiarity in eyes (part-based, region-selective) and holistic processing. Face familiarity was tested at three levels: high-familiar (faces of students from the same department and the same class who attended almost all courses together), low-familiar (faces of students from the same department but different classes who attended some courses together), and unfamiliar (faces of schoolmates from different departments who seldom attended the same courses). Using the old/new task in Experiment 1, we found that participants recognized eyes of high-familiar faces better than low-familiar and unfamiliar ones, while similar performance was observed for mouths, indicating a region-selective, eyes familiarity effect. Using the "Perceptual field" paradigm in Experiment 2, we observed a stronger inversion effect for high-familiar faces, a weaker inversion effect for low-familiar faces, but a non-significant inversion effect for unfamiliar faces, indicating that face familiarity plays a role in holistic processing. Taken together, our results suggest that familiarity, like other experience-based variables (e.g., race and species), can improve both eye processing and holistic processing.

A neural marker of the human face identity familiarity effect

Human adults associate different views of an identity much better for familiar than for unfamiliar faces. However, a robust and consistent neural index of this behavioral face identity familiarity effect (FIFE)—not found in non-human primate species—is lacking. Here we provide such a neural FIFE index, measured implicitly and with one fixation per face. Fourteen participants viewed 70 s stimulation sequences of a large set (n = 40) of widely variable natural images of a face identity at a rate of 6 images/second (6 Hz). Different face identities appeared every 5th image (1.2 Hz). In a sequence, face images were either familiar (i.e., famous) or unfamiliar, participants performing a non-periodic task unrelated to face recognition. The face identity recognition response identified at 1.2 Hz over occipital-temporal regions in the frequency-domain electroencephalogram was 3.4 times larger for familiar than unfamiliar faces. The neural response to familiar faces—which emerged at about 180 ms following face onset—was significant in each individual but a case of prosopdysgnosia. Besides potential clinical and forensic applications to implicitly measure one’s knowledge of a face identity, these findings open new perspectives to clarify the neurofunctional source of the FIFE and understand the nature of human face identity recognition.

Management of separation anxiety in pediatric patients in a dental setting

To inculcate a better understanding and facilitate a better management of separation anxiety seen in children in dental clinic. Separation anxiety is often seen in pediatric patients. Although, not much thought is given to it as parents presume the anxiety to be merely a byproduct of a new environment and unfamiliar faces. It was significant to compile separation anxiety seen in children with a special emphasis on its dental aspect which will aid pedodontists as well as general practitioners in a swift recognition of the symptoms followed by prompt management of pediatric separation anxiety patients in a dental setting.

The unity hypothesis revisited: can the male/female incongruent McGurk effect be disrupted by familiarization and priming?

The unity assumption hypothesis contends that higher-level factors, such as a perceiver's belief and prior experience, modulate multisensory integration. The McGurk illusion exemplifies such integration. When a visual velar consonant /ga/ is dubbed with an auditory bilabial /ba/, listeners unify the discrepant signals with knowledge that open lips cannot produce /ba/ and a fusion percept /da/ is perceived. Previous research claimed to have falsified the unity assumption hypothesis by demonstrating the McGurk effect occurs even when a face is dubbed with a voice of the opposite sex, and thus violates expectations from prior experience. But perhaps stronger counter-evidence is needed to prevent perceptual unity than just an apparent incongruence between unfamiliar faces and voices. Here we investigated whether the McGurk illusion with male/female incongruent stimuli can be disrupted by familiarization and priming with an appropriate pairing of face and voice. In an online experiment, the susceptibility of participants to the McGurk illusion was tested with stimuli containing either a male or female face with a voice of incongruent gender. The number of times participants experienced a McGurk illusion was measured before and after a familiarization block, which familiarized them with the true pairings of face and voice. After familiarization and priming, the susceptibility to the McGurk effects decreased significantly on average. The findings support the notion that unity assumptions modulate intersensory bias, and confirm and extend previous studies using male/female incongruent McGurk stimuli.