Face Inversion Effect Research Articles

Face masks disrupt holistic processing and face perception in school-age children

Face perception is considered a remarkable visual ability in humans that is subject to a prolonged developmental trajectory. In response to the COVID-19 pandemic, mask-wearing has become mandatory for adults and children alike. Recent research shows that mask-wearing hinders face recognition abilities in adults, but it is unknown if the same holds true in school-age children in whom face perception is not fully developed. Here we tested children (n = 72, ages 6–14 years old) on the Cambridge Face Memory Test – Kids (CFMT-K), a validated measure of face perception performance. Faces were presented with or without masks and across two orientations (upright/inverted). The inclusion of face masks led to a profound deficit in face perception abilities. This decrement was more pronounced in children compared to adults, but only when task difficulty was adjusted across the two age groups. Additionally, children exhibited reliable correlations between age and the CFMT-K score for upright faces for both the mask and no-mask conditions. Finally, as previously observed in adults, children also showed qualitative differences in the processing of masked versus non-masked faces. Specifically, holistic processing, a hallmark of face perception, was disrupted for masked faces as suggested by a reduced face-inversion effect. Together, these findings provide evidence for substantial quantitative and qualitative alterations in the processing of masked faces in school-age children.

Face-Specific Pupil Contagion in Infants.

Pupil contagion is the phenomenon in which an observer’s pupil-diameter changes in response to another person’s pupil. Even chimpanzees and infants in early development stages show pupil contagion. This study investigated whether dynamic changes in pupil diameter would induce changes in infants’ pupil diameter. We also investigated pupil contagion in the context of different faces. We measured the pupil-diameter of 50 five- to six-month-old infants in response to changes in the pupil diameter (dilating/constricting) of upright and inverted faces. The results showed that (1) in the upright presentation condition, dilating the pupil diameter induced a change in the infants’ pupil diameter while constricting the pupil diameter did not induce a change, and (2) pupil contagion occurred only in the upright face presentation, and not in the inverted face presentation. These results indicate the face-inversion effect in infants’ pupil contagion.

Understanding the Impact of Face Masks on the Processing of Facial Identity, Emotion, Age, and Gender.

The COVID-19 pandemic has introduced new challenges for governments and individuals. Unprecedented efforts at reducing virus transmission launched a novel arena for human face recognition in which faces are partially occluded with masks. Previous studies have shown that masks decrease accuracy of face identity and emotion recognition. The current study focuses on the impact of masks on the speed of processing of these and other important social dimensions. Here we provide a systematic assessment of the impact of COVID-19 masks on facial identity, emotion, gender, and age. Four experiments (N = 116) were conducted in which participants categorized faces on a predefined dimension (e.g., emotion). Both speed and accuracy were measured. The results revealed that masks hindered the perception of virtually all tested facial dimensions (i.e., emotion, gender, age, and identity), interfering with normal speed and accuracy of categorization. We also found that the unwarranted effects of masks were not due to holistic processes, because the Face Inversion Effect (FIE) was generally not larger with unmasked compared with masked faces. Moreover, we found that the impact of masks is not automatic and that under some contexts observers can control at least part of their detrimental effects.

Extensive visual training in adulthood reduces an implicit neural marker of the face inversion effect

Extensive visual training in adulthood reduces an implicit neural marker of the face inversion effect

Robot faces elicit responses intermediate to human faces and objects at face-sensitive ERP components

Face recognition is supported by selective neural mechanisms that are sensitive to various aspects of facial appearance. These include event-related potential (ERP) components like the P100 and the N170 which exhibit different patterns of selectivity for various aspects of facial appearance. Examining the boundary between faces and non-faces using these responses is one way to develop a more robust understanding of the representation of faces in extrastriate cortex and determine what critical properties an image must possess to be considered face-like. Robot faces are a particularly interesting stimulus class to examine because they can differ markedly from human faces in terms of shape, surface properties, and the configuration of facial features, but are also interpreted as social agents in a range of settings. In the current study, we thus chose to investigate how ERP responses to robot faces may differ from the response to human faces and non-face objects. In two experiments, we examined how the P100 and N170 responded to human faces, robot faces, and non-face objects (clocks). In Experiment 1, we found that robot faces elicit intermediate responses from face-sensitive components relative to non-face objects (clocks) and both real human faces and artificial human faces (computer-generated faces and dolls). These results suggest that while human-like inanimate faces (CG faces and dolls) are processed much like real faces, robot faces are dissimilar enough to human faces to be processed differently. In Experiment 2 we found that the face inversion effect was only partly evident in robot faces. We conclude that robot faces are an intermediate stimulus class that offers insight into the perceptual and cognitive factors that affect how social agents are identified and categorized.

Do facially disfiguring features influence attention and perception of faces? Evidence from an antisaccade task.

Facial disfigurements can influence how observers attend to and interact with the person, leading to disease-avoidance behaviour and emotions (disgust, threat, fear for contagion). However, it is unclear whether this behaviour is reflected in the effect of the facial stigma on attention and perceptual encoding of facial information. We addressed this question by measuring, in a mixed antisaccade task, observers’ speed and accuracy of orienting of visual attention towards or away from peripherally presented upright and inverted unfamiliar faces that had either a realistic looking disease-signalling feature (a skin discolouration), a non-disease-signalling control feature, or no added feature. The presence of a disfiguring or control feature did not influence the orienting of attention (in terms of saccadic latency) towards upright faces, suggesting that avoidance responses towards facial stigma do not occur during covert attention. However, disfiguring and control features significantly reduced the effect of face inversion on saccadic latency, thus suggesting an impact on the holistic processing of facial information. The implications of these findings for the encoding and appraisal of facial disfigurements are discussed.

Effect of Individual Differences in Fear and Anxiety on Face Perception of Human and Android Agents

People process human faces configurally—as a Gestalt or integrated whole—but perceive objects in terms of their individual features. As a result, faces—but not objects—are more difficult to process when presented upside down versus upright. Previous research demonstrates that this inversion effect is not observed when recognizing previously seen android faces, suggesting they are processed more like objects, perhaps due to a lack of perceptual experience and/or motivation to recognize android faces. The current study aimed to determine whether negative emotions, particularly fear of androids, may lessen configural processing of android faces compared to human faces. While the current study replicated previous research showing a greater inversion effect for human compared to android faces, we did not find evidence that negative emotions—such as fear—towards androids influenced the face inversion effect. We discuss the implications of this study and opportunities for future research.

Aging, pattern separation, and categorical perception of faces

Categorical perception (CP) is the phenomenon by which observers view linear changes that occur across a continuum as distinct categories. Although categorical perception is a perceptual phenomenon, it may be subserved by mnemonic processes such as pattern separation. To examine this hypothesis, following standard CP tasks, we assessed younger and older participants’ abilities to identify and discriminate between members of pairs of famous or non-famous faces. We hypothesized that if CP is dependent upon neural pattern separation, which declines with aging, discrimination ability as indexed by CP would be compromised in older adults, as was found in our study. Since familiarity promotes pattern separation, CP should be enhanced for famous, as compared to non-famous faces, even in older adults. We found that all participants benefited from familiarity, but younger adults outperformed older adults overall. We next examined the effects of face inversion on CP for both famous and non-famous faces. If pattern separation, and CP, is determined solely by the similarity across physical features, then CP should be similar for upright and inverted faces since these features are perceptually invariant across orientation. If, however, pattern separation, and CP, depends on how stimuli are represented, then orientation may matter as upright and inverted faces are represented holistically or part-based, respectively. We found that inversion disrupted CP in younger adults whereas older adults performed similarly across both conditions, suggesting that face-representation is more part-based in older adults.

Different measures of holistic face processing tap into distinct but partially overlapping mechanisms.

Holistic processing, which includes the integration of facial features and analysis of their relations to one another, is a hallmark of what makes faces 'special'. Various experimental paradigms purport to measure holistic processing but these have often produced inconsistent results. This has led researchers to question the nature and structure of the mechanism(s) underlying holistic processing. Using an individual differences approach, researchers have examined relations between various measures of holistic processing in an attempt to resolve these questions. In keeping with this, we examined relationships between four commonly used measures of holistic face processing in a large group of participants (N = 223): (1) The Face Inversion Effect, (2) the Part Whole Effect (PWE), (3) the Composite Face Effect, and (4) the Configural Featural Detection Task (CFDT). Several novel methodological and analytical elements were introduced, including the use of factor analysis and the inclusion of control conditions to confirm the face specificity of all of the effects measured. The four indexes of holistic processing derived from each measure loaded onto two factors, one encompassing the PWE and the CFDT, and one encompassing the CE. The 16 conditions tested across the four tasks loaded onto four factors, each factor corresponding to a different measure. These results, together with those of other studies, suggest that holistic processing is a multifaceted construct and that different measures tap into distinct but partially overlapping elements of it.

Cortical Pathways or Mechanism in the Face Inversion Effect in Patients with First-Episode Schizophrenia.

ObjectiveImpaired face perception is considered as a hallmark of social disability in schizophrenia. It is widely believed that inverted faces and upright faces are processed by distinct mechanisms. Previous studies have identified that individuals with schizophrenia display poorer face processing than controls. However, the mechanisms underlying the face inversion effect (FIE) in patients with first-episode schizophrenia (FSZ) remain unclear.MethodsWe designed an fMRI task to investigate the FIE mechanism in patients with schizophrenia. Thirty-four patients with FSZ and thirty-five healthy controls (CON) underwent task-related fMRI scanning, clinical assessment, anhedonia experience examination, and social function and cognitive function evaluation.ResultsThe patients with FSZ exhibited distinct functional activity regarding upright and inverted face processing within the cortical face and non-face network. These results suggest that the differences in quantitative processing might mediate the FIE in schizophrenia. Compared with controls, affected patients showed impairments in processing both upright and inverted faces; and for these patients with FSZ, upright face processing was associated with more severe and broader impairment than inverted face processing. Reduced response in the left middle occipital gyrus for upright face processing was related to poorer performance of social function outcomes evaluated using the Personal and Social Performance Scale.ConclusionOur data suggested that patients with FSZ exhibited similar performance in processing inverted faces and upright faces, but were less efficient than controls; and for these patients, inverted faces are processed less efficiently than upright faces. We also provided a clue that the mechanism under abnormal FIE might be related to an aberrant activation of non-face-selective areas instead of abnormal activation of face-specific areas in patients with schizophrenia. Finally, our study indicated that the neural pathway for upright recognition might be relevant in determining the functional outcomes of this devastating disorder.

Sorry, baby: Infant faces reach awareness more slowly than adult faces.

Past research has found an attentional bias for positive relative to neutral stimuli, with a greater attentional bias for stimuli that are more motivationally relevant. Baby faces are an example of a motivationally relevant stimulus because they elicit caretaking behaviors. Building on previous work demonstrating that baby faces capture attention, the current study used breaking continuous flash suppression (bCFS) to investigate whether infant faces are prioritized for access to awareness. On each trial of the task, a face was shown to one eye and a rapidly changing Mondrian pattern to the other. Participants were asked to report the location of the face as soon as it emerged from suppression. The faces were either infant or adult faces, presented in upright or inverted orientation. Despite evidence suggesting that infant faces might reach awareness more quickly than adult faces, the opposite was found: Adult faces reached awareness more quickly than infant faces. Moreover, a stronger face inversion effect was observed for adult versus infant faces, indicating that the shorter suppression times for adult faces were due to increased expertise with adult faces. A past bCFS study demonstrated an own-age face effect for young adults, but it left open the possibility that this effect was due to the youthful appearance of the young versus old faces. The current results rule out this possibility and provide further support for the idea that experience with faces of one's own social group facilitates the access of those faces to awareness. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Gender differences in face recognition: The role of holistic processing

ABSTRACT Previous studies have found a female advantage in face recognition ability. The present study sought to replicate this finding in a large sample of 343 Danish psychology students using the Cambridge Face Memory Test (CFMT) and the Cambridge Face Perception Test (CFPT). Furthermore, we examined whether a potential female advantage could be explained by more efficient holistic processing indexed by the face inversion effect: a disproportionately larger effect of inversion on face than object processing (dFIE). Here we used the Cambridge Car Memory Test (CCMT) as the control task with cars as the object category. In accordance with previous studies, the results showed a female advantage in face processing both on the CFMT and the CFPT. No gender difference in the dFIE was found, however, indicating that more efficient holistic processing does not underlie the female advantage in face recognition.

Amplified inversion effects for moving biological stimuli remain largest for faces and bodies.

Turning an object upside-down disrupts our ability to perceive it accurately, and this inversion effect is disproportionately larger for faces and whole bodies than most other objects. This disproportionate inversion effect is taken as an indicator of holistic processing for these stimuli. Large inversion effects are also found when viewing motion-only information from faces and bodies; however, these have not been compared to other moving objects in an identity task so it is unclear whether inversion effects remain disproportionately larger for faces and bodies when they are engaged in motion. The current study investigated the effect of inversion on static and moving unfamiliar faces, human bodies, and German Shepherd dogs in an old-new recognition memory task. Sensitivity and baseline corrected reaction time (RT) results revealed that inversion effects for faces and whole-bodies remained disproportionately larger than those for German Shepherd dogs, regardless of presentation type, suggesting that both static and moving faces and bodies are processed holistically.

Using transcranial Direct Current Stimulation (tDCS) to investigate why faces are and are not special

We believe we are now in a position to answer the question, "Are faces special?" inasmuch as this applies to the face inversion effect (better performance for upright vs inverted faces). Using a double-blind, between-subject design, in two experiments (n = 96) we applied a specific tDCS procedure targeting the Fp3 area while participants performed a matching-task with faces (Experiment 1a) or checkerboards from a familiar prototype-defined category (Experiment 1b). Anodal tDCS eliminated the checkerboard inversion effect reliably obtained in the sham group, but only reduced it for faces (although the reduction was significant). Thus, there is a component to the face inversion effect that we are not affecting with a tDCS procedure that can eliminate the checkerboard inversion effect. We suggest that the reduction reflects the loss of an expertise-based component in the face inversion effect, and the residual is due to a face-specific component of that effect.

The effects of transcranial direct current stimulation on perceptual learning for upright faces and its role in the composite face effect.

In the 3 experiments reported here we show that a specific neurostimulation method, whose influence can be understood in terms of a well-known theory of stimulus representation, is able to affect face recognition skills by impairing participants' performance for upright faces. We used the transcranial Direct Current Stimulation (tDCS) procedure we have recently developed that allows perceptual learning, as indexed by the face inversion effect, to be modulated. We extended this tDCS procedure to another phenomenon, the composite face effect, which constitutes better recognition of the top half of an upright face when conjoined with a congruent (in terms of the response required) rather than incongruent bottom half. All three experiments used the Face-Matching task traditionally used to study this phenomenon. Experiment 1a (n = 48) showed that anodal tDCS (using a double-blind between-subjects design) delivered at Fp3 (10 mins at 1.5 mA) affected overall performance for upright faces compared with sham but had no effect on the composite face effect itself. Experiment 1b (n = 48) replicated our usual tDCS-induced effects on the face inversion effect but this time using a Face-Matching task instead of the old/new recognition task previously used to obtain the effect. Experiment 2 (n = 72) replicated the findings from Experiment 1a, and, using an active control group, showed that the Fp3 anodal tDCS effects on performance to upright faces are not obtained when a different brain area is targeted. We interpret our results in the light of previous literature on the tDCS effects on perceptual learning and face recognition and suggest that different mechanisms are involved in the face inversion effect and the composite face effect. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Face Recognition Deficits in a Patient With Alzheimer's Disease: Amnesia or Agnosia? The Importance of Electrophysiological Markers for Differential Diagnosis

Face recognition deficits are frequently reported in Alzheimer's disease (AD) and often attributed to memory impairment. However, it has been hypothesized that failure in identifying familiar people could also be due to deficits in higher-level perceptual processes, since there is evidence showing a reduced inversion effect for faces but not for cars in AD. To address the involvement of these higher processes, we investigated event-related potential (ERP) neural correlates of faces in a patient with AD showing a face recognition deficit. Eight healthy participants were tested as a control group. Participants performed different tasks following the stimulus presentation. In experiment 1, they should indicate whether the stimulus was either a face or a house or a scrambled image. In experiments 2 and 3, they should discriminate between upright and inverted faces (in experiment 2, stimuli were faces with neutral or fearful expressions, while in experiment 3, stimuli were famous or unfamiliar faces). Electrophysiological results reveal that the typical face-specific modulation of the N170 component, which is thought to reflect the structural encoding of faces, was not present in patient MCG, despite being affected by the emotional content of the face implicitly processed by MCG. Conversely, the N400 component, which is thought to reflect the recruitment of the memory trace of the face identity, was found to be implicitly modulated in MCG. These results may identify a possible role for gnosic processes in face recognition deficits in AD and suggest the importance of adopting an integrated approach to the AD diagnosis while considering electrophysiological markers.

Turning the Face Inversion Effect on Its Head: Violated Expectations of Orientation, Lighting, and Gravity Enhance N170 Amplitudes.

Face inversion effects occur for both behavioral and electrophysiological responses when people view faces. In EEG, inverted faces are often reported to evoke an enhanced amplitude and delayed latency of the N170 ERP. This response has been attributed to the indexing of specialized face processing mechanisms within the brain. However, inspection of the literature revealed that, although N170 is consistently delayed to a variety of face representations, only photographed faces invoke enhanced N170 amplitudes upon inversion. This suggests that the increased N170 amplitudes to inverted faces may have other origins than the inversion of the face's structure. We hypothesize that the unique N170 amplitude response to inverted photographed faces stems from multiple expectation violations, over and above structural inversion. For instance, rotating an image of a face upside-down not only violates the expectation that faces appear upright but also lifelong priors about illumination and gravity. We recorded EEG while participants viewed face stimuli (upright vs. inverted), where the faces were illuminated from above versus below, and where the models were photographed upright versus hanging upside-down. The N170 amplitudes were found to be modulated by a complex interaction between orientation, lighting, and gravity factors, with the amplitudes largest when faces consistently violated all three expectations. These results confirm our hypothesis that face inversion effects on N170 amplitudes are driven by a violation of the viewer's expectations across several parameters that characterize faces, rather than a disruption in the configurational disposition of its features.

Birthweight predicts individual differences in adult face recognition ability.

It has long been known that premature birth and/or low birthweight can lead to general difficulties in cognitive and emotional functioning throughout childhood. However, the influence of these factors on more specific processes has seldom been addressed, despite their potential to account for wide individual differences in performance that often appear innate. Here, we examined the influence of gestation and birthweight on adults' face perception and face memory skills. Performance on both sub-processes was predicted by birthweight and birthweight-for-gestation, but not gestation alone. Evidence was also found for the domain-specificity of these effects: No perinatal measure correlated with performance on object perception or memory tasks, but they were related to the size of the face inversion effect on the perceptual test. This evidence indicates a novel, very early influence on individual differences in face recognition ability, which persists into adulthood, influences face-processing strategy itself, and may be domain-specific.

Reduced left visual field bias for faces in adolescents with social anxiety disorder

ABSTRACT Introduction: Individuals tend to explore the left side of a face first and for a longer time in comparison to the right side. This left visual field (LVF) bias is suggested to reflect right hemispheric dominance for face processing. Social anxiety disorder (SAD) is associated with maladaptive interpretations of facial expressions, but it is not known whether this is linked to an atypical LVF bias. Previous studies have reported a reduced LVF bias in autism, a condition overlapping with SAD. This pre-registered study examined the LVF bias in adolescents with SAD. Methods: Eye-tracking was used to investigate the ratio of first fixations to the left on upright and inverted face stimuli in 26 adolescents (13-17 years) with SAD and 23 healthy controls primed to look either between the eyes or at the mouth. Results: The SAD group showed a smaller LVF bias and an atypical face inversion effect when primed to look at the eyes. Autistic traits predicted a smaller LVF bias, independently of social anxiety level. Conclusions: Results suggest that SAD is associated with impaired processing of faces at an early stage of visual scanning. The findings contribute to a better understanding of SAD and its overlap with autism.

Getting to the heart of it: Multi-method exploration of nonconscious prioritization processes.

Understanding the determinants of consciousness is crucial for theories that see it as functionally adaptive, and for explaining how consciousness affects higher-level cognition. The invention of continuous flash suppression (CFS), a long-duration suppression technique, resulted in a proliferation of research into the process of prioritization for consciousness. We developed a new technique, repeated masked suppression (RMS), that facilitates the measurement of long suppression times, but relies on different visual principles. RMS enables a theoretical leap: It allows scientists to examine the central process of prioritization across different suppression methods. In five experiments (n = 282) we collected chronometric RMS and CFS data, finding that the previously reported face inversion effect and the face priority-dimension generalize beyond CFS. Our results validate the use of multi-method designs in the study of prioritization for consciousness. Furthermore, we show how RMS could be used online to reach diverse samples, previously beyond the reach of consciousness science.