How do we update faces? Effects of gaze direction and facial expressions on working memory updating

Working memory for gaze benefits from the face context

Retaining gaze in working memory (WM) is essential for successfully navigating through the social world. In the current study, we investigated how WM stores gaze direction by focusing on the role of face context in gaze WM. To address this question, we propose two competing hypotheses. The independence hypothesis predicts that eye gaze is stored independently and is not susceptible to the influence of the surrounding face context. Conversely, the embedding hypothesis claims that gaze WM involves face context and that disruption of holistic face processing would also impair memory for embedded gaze. In three experiments, we adopted different manipulations to disrupt holistic face processing and compared WM performance for gaze within and without face context. In Experiments 1 and 2, we tested WM for gaze direction with schematic upright or inverted faces. We found better performance for gaze within upright faces (vs. inverted faces) by increasing the probability of being remembered. In Experiment 3, we replaced schematic faces with photographic faces, and disrupted holistic processing by using scrambled faces. Results replicated our previous findings, showing that photographic gaze within intact faces was better remembered than gaze presented alone or gaze within scrambled faces. These findings indicate that gaze memory is face-dependent and support the embedding hypothesis.

Illumination and gaze effects on face evaluation: The Bi-AGI database

Face evaluation and first impression generation can be affected by multiple face elements such as invariant facial features, gaze direction and environmental context; however, the composite modulation of eye gaze and illumination on faces of different gender and ages has not been previously investigated. We aimed at testing how these different facial and contextual features affect ratings of social attributes. Thus, we created and validated the Bi-AGI Database, a freely available new set of male and female face stimuli varying in age across lifespan from 18 to 87 years, gaze direction and illumination conditions. Judgments on attractiveness, femininity-masculinity, dominance and trustworthiness were collected for each stimulus. Results evidence the interaction of the different variables in modulating social trait attribution, in particular illumination differently affects ratings across age, gaze and gender, with less impact on older adults and greater effect on young faces.

Preverbal infants tune manual choices on subliminal affective information

Human behaviour is often shaped by unconscious emotional cues. From early on, infants are able to process emotional signals even if presented subliminally; however, whether subliminal emotional expressions are capable to affect infants' behaviour remains unknown. The current study aimed to fill this gap, recording 8-10-month-old infants' looking time and manual choice toward two objects previously associated to subliminal emotional faces. Results demonstrated that infants' manual choice, but not looking time, was guided by the previously presented subliminal emotional signal, as infants preferred to choose the object associated to the happy face. Overall, our findings show that preverbal infants tune their behaviour based on affective information, which drives them towards or away from previous encounters, even outside conscious awareness.

The role of discriminability in face perception: Interference processing of expression, gender, and gaze

Eye gaze plays a fundamental role in social interaction and facial recognition. However, interference processing between gaze and other facial variants (e.g., expression) and invariant information (e.g., gender) remains controversial and unclear, especially the role of facial information discriminability in interference. A Garner paradigm was used to conduct two experiments. This paradigm allows simultaneous investigation of the mutual influence of two kinds of facial information in one experiment. In Experiment 1, we manipulated facial expression discriminability and investigated its role in interference processing of gaze and facial expression. The results show that individuals were unable to ignore expression when classifying gaze with both high and low discriminability but could ignore gaze when classifying expression with high discriminability only. In Experiment 2, we manipulated gender discriminability and investigated its function in interference processing of gaze and gender. Participants were unable to ignore gender when classifying gaze with both high and low discriminability but could ignore gaze when classifying gender with low discriminability only. The results indicate that gaze categorization is affected by facial expression and gender regardless of facial information discriminability, whereas interference of gaze on facial expression and gender depends on the degree of discriminability. The present study provides evidence that the processing of gaze and other variant and invariant information is interdependent.

Memory updating through aging: different patterns for socially meaningful (and not) stimuli

BACKGROUND

Updating is a crucial function responsible of working memory integrity, allowing relevant information to be active and inhibiting irrelevant one; updating has been studied mainly with verbal stimuli, less with faces, stimuli with high adaptive value and social meaning.

AIM

Our aim was to test age-related differences in updating for different stimuli in three different age groups: young adults (range 20-30 years), young-old (range 60-75 years) and older-old participants (range 77-87 years).

METHODS

To this end, we administered control measures (i.e., vocabulary and visuospatial tasks), span tasks (forward, backward) and two updating tasks: one with no socially relevant material (i.e., letters) and another one with socially relevant material (i.e., human faces, where, in particular, the combination between facial expression and gaze direction was manipulated). In both tasks we collected response times (RTs) at different steps of an updating task (i.e., encoding, maintaining, and updating goal-relevant information).

RESULTS AND DISCUSSION

We found that age linearly produces an increase in processing speed regardless the stimulus considered, either letter or human face. However, with face stimuli, the magnitude of the difference is greater for the letter updating task, than for the face updating task. In turn, the results claim for a stimulus-specific updating process as the age-related decline is less pronounced when socially meaningful stimuli are involved than when no socially meaningful ones are.

Recognizing Emotions through Facial Expressions: A Largescale Experimental Study

Experimental research examining emotional processes is typically based on the observation of images with affective content, including facial expressions. Future studies will benefit from databases with emotion-inducing stimuli in which characteristics of the stimuli potentially influencing results can be controlled. This study presents Portuguese normative data for the identification of seven facial expressions of emotions (plus a neutral face), on the Radboud Faces Database (RaFD). The effect of participants’ gender and models’ sex on emotion recognition was also examined. Participants (N = 1249) were exposed to 312 pictures of white adults displaying emotional and neutral faces with a frontal gaze. Recognition agreement between the displayed and participants’ chosen expressions ranged from 69% (for anger) to 97% (for happiness). Recognition levels were significantly higher among women than among men only for anger and contempt. The emotion recognition was higher either in female models or in male models depending on the emotion. Overall, the results show high recognition levels of the facial expressions presented, indicating that the RaFD provides adequate stimuli for studies examining the recognition of facial expressions of emotion among college students. Participants’ gender had a limited influence on emotion recognition, but the sex of the model requires additional consideration.

How social exclusion modulates social information processing: A behavioural dissociation between facial expressions and gaze direction

Social exclusion is a painful experience that is felt as a threat to the human need to belong and can lead to increased aggressive and anti-social behaviours, and results in emotional and cognitive numbness. Excluded individuals also seem to show an automatic tuning to positivity: they tend to increase their selective attention towards social acceptance signals. Despite these effects known in the literature, the consequences of social exclusion on social information processing still need to be explored in depth. The aim of this study was to investigate the effects of social exclusion on processing two features that are strictly bound in the appraisal of the meaning of facial expressions: gaze direction and emotional expression. In two experiments (N = 60, N = 45), participants were asked to identify gaze direction or emotional expressions from facial stimuli, in which both these features were manipulated. They performed these tasks in a four-block crossed design after being socially included or excluded using the Cyberball game. Participants’ empathy and self-reported emotions were recorded using the Empathy Quotient (EQ) and PANAS questionnaires. The Need Threat Scale and three additional questions were also used as manipulation checks in the second experiment. In both experiments, excluded participants showed to be less accurate than included participants in gaze direction discrimination. Modulatory effects of direct gaze (Experiment 1) and sad expression (Experiment 2) on the effects of social exclusion were found on response times (RTs) in the emotion recognition task. Specific differences in the reaction to social exclusion between males and females were also found in Experiment 2: excluded male participants tended to be less accurate and faster than included male participants, while excluded females showed a more accurate and slower performance than included female participants. No influence of social exclusion on PANAS or EQ scores was found. Results are discussed in the context of the importance of identifying gaze direction in appraisal theories.

The nature and emotional valence of a prime influences the processing of emotional faces in adults and children

A large body of research has investigated both the emotional elaboration of facial stimuli in adults and the development of children’s recognition of emotional expressions. Yet, it is still not clear whether children’s ability to recognize an emotional face may be modulated by prior exposure to a different face, and whether an emotional expression may exert an effect on the processing of subsequently encountered facial emotional expressions. We tested in three experiments the recognition of happy and angry target faces preceded by neutral faces or objects (Experiment 1) and happy or angry faces (Experiment 2A and Experiment 2B) using an affective priming task in adults and 7- and 5-year-old children. Results showed a standard prime effect for neutral faces (Experiment 1) for all participants, and for happy faces in children (Experiment 2A) and adults (Experiment 2B). Otherwise, angry faces elicited negative priming effects in all participants (Experiment 2A). Overall, our findings showed that both prior exposure to a face per se and the emotional valence of the prime face have an impact on subsequent processing of facial emotional information. Implications for emotional processing are discussed.

Trait Anxiety Impacts the Perceived Gaze Direction of Fearful But Not Angry Faces

Facial expression and gaze direction play an important role in social communication. Previous research has demonstrated the perception of anger is enhanced by direct gaze, whereas, it is unclear whether perception of fear is enhanced by averted gaze. In addition, previous research has shown the anxiety affects the processing of facial expression and gaze direction, but hasn't measured or controlled for depression. As a result, firm conclusions cannot be made regarding the impact of individual differences in anxiety and depression on perceptions of face expressions and gaze direction. The current study attempted to reexamine the effect of the anxiety level on the processing of facial expressions and gaze direction by matching participants on depression scores. A reliable psychophysical index of the range of eye gaze angles judged as being directed at oneself [the cone of direct gaze (CoDG)] was used as the dependent variable in this study. Participants were stratified into high/low trait anxiety groups and asked to judge the gaze of angry, fearful, and neutral faces across a range of gaze directions. The result showed: (1) the perception of gaze direction was influenced by facial expression and this was modulated by trait anxiety. For the high trait anxiety group, the CoDG for angry expressions was wider than for fearful and neutral expressions, and no significant difference emerged between fearful and neutral expressions; For the low trait anxiety group, the CoDG for both angry and fearful expressions was wider than for neutral, and no significant difference emerged between angry and fearful expressions. (2) Trait anxiety modulated the perception of gaze direction only in the fearful condition, such that the fearful CoDG for the high trait anxiety group was narrower than the low trait anxiety group. This demonstrated that anxiety distinctly affected gaze perception in expressions that convey threat (angry, fearful), such that a high trait anxiety level modulated the impact of indirectly threatening expressions (fearful), and did not influence responses to directly threatening expression (angry). These findings partially support the shared signal hypothesis.

Updating schematic emotional facial expressions in working memory: Response bias and sensitivity

It is unclear if positive, negative, or neutral emotional expressions have an advantage in short-term recognition. Moreover, it is unclear from previous studies of working memory for emotional faces whether effects of emotions comprise response bias or sensitivity. The aim of this study was to compare how schematic emotional expressions (sad, angry, scheming, happy, and neutral) are discriminated and recognized in an updating task (2-back recognition) in a representative sample of birth cohort of young adults. Schematic facial expressions allow control of identity processing, which is separate from expression processing, and have been used extensively in attention research but not much, until now, in working memory research. We found that expressions with a U-curved mouth (i.e., upwardly curved), namely happy and scheming expressions, favoured a bias towards recognition (i.e., towards indicating that the probe and the stimulus in working memory are the same). Other effects of emotional expression were considerably smaller (1-2% of the variance explained)) compared to a large proportion of variance that was explained by the physical similarity of items being compared. We suggest that the nature of the stimuli plays a role in this. The present application of signal detection methodology with emotional, schematic faces in a working memory procedure requiring fast comparisons helps to resolve important contradictions that have emerged in the emotional perception literature.

Binding and content updating in working memory tasks

Working memory updating can involve processing of either a specific memory content or a binding. So far, research has focused mainly on single contents as objects of updating, via recall accuracy measures. Here, we have addressed more direct measurement of the updating process (i.e., response times), assessing individually the role of single contents, as well as bindings. To this end, we compared two updating tasks from separate research traditions: a RT-based computer task and a classical accuracy-based task. The former consisted of trials where measures of content and binding updating were obtained, allowing a dissociation between these two components. The latter measured recall accuracy and intrusion rate for lists of words under different conditions of maintenance/inhibition. These results enable a better understanding of the updating process for the dual components of binding and content updating, and their potential role in an accuracy-based task. An overlap between the underlying components of updating tasks was demonstrated, specifically between binding updating RT and intrusion rate. Notably, binding updating appears to be a more sensitive measure in explaining results in the classical updating task.