Integration of internal and external facial features in 8- to 10-year-old children and adults

Investigation of whole-part and composite effects in 4- to 6-year-old children gave rise to claims that face perception is fully mature within the first decade of life (Crookes & McKone, 2009). However, only internal features were tested, and the role of external features was not addressed, although external features are highly relevant for holistic face perception (Sinha & Poggio, 1996; Axelrod & Yovel, 2010, 2011). In this study, 8- to 10-year-old children and adults performed a same–different matching task with faces and watches. In this task participants attended to either internal or external features. Holistic face perception was tested using a congruency paradigm, in which face and non-face stimuli either agreed or disagreed in both features (congruent contexts) or just in the attended ones (incongruent contexts). In both age groups, pronounced context congruency and inversion effects were found for faces, but not for watches. These findings indicate holistic feature integration for faces. While inversion effects were highly similar in both age groups, context congruency effects were stronger for children. Moreover, children's face matching performance was generally better when attending to external compared to internal features. Adults tended to perform better when attending to internal features. Our results indicate that both adults and 8- to 10-year-old children integrate external and internal facial features into holistic face representations. However, in children's face representations external features are much more relevant. These findings suggest that face perception is holistic but still not adult-like at the end of the first decade of life.     

What Stroop tasks can tell us about selective attention from childhood to adulthood

A rich body of research concerns causes of Stroop effects plus applications of Stroop. However, several questions remain. We included assessment of errors with children and adults (N = 316), who sat either a task wherein each block employed only trials of one type (unmixed task) or where every block comprised of a mix of the congruent, neutral, and incongruent trials. Children responded slower than adults and made more errors on each task. Contrary to some previous studies, interference (the difference between neutral and incongruent condition) showed no reaction time (RT) differences by group or task, although there were differences in errors. By contrast, facilitation (the difference between neutral and congruent condition) was greater in children than adults, and greater on the unmixed task than the mixed task. After considering a number of theoretical accounts, we settle on the inadvertent word‐reading hypothesis, whereby facilitation stems from children and the unmixed task promoting inadvertent reading particularly in the congruent condition. Stability of interference RT is explained by fixed semantic differences between neutral and incongruent conditions, for children versus adults and for unmixed versus mixed task. We conclude that utilizing two tasks together may reveal more about how attention is affected in other groups.     

Depth of facial expression processing depends on stimulus visibility: Behavioral and electrophysiological evidence of priming effects

Participants performed a priming task during which emotional faces served as prime stimuli and emotional words served as targets. Prime-target pairs were congruent or incongruent, and two levels of prime visibility were obtained by varying the duration of the masked primes. To probe a neural signature of the impact of the masked primes, lateralized readiness potentials (LRPs) were recorded over motor cortex. In the high-visibility condition, responses to word targets were faster when the prime-target pairs were congruent than when they were incongruent, providing evidence of priming effects. In line with the behavioral results, the electrophysiological data showed that high-visibility face primes resulted in LRP differences between congruent and incongruent trials, suggesting that prime stimuli initiated motor preparation. Contrary to the above pattern, no evidence for reaction time or LRP differences was observed in the low-visibility condition, revealing that the depth of facial expression processing is dependent on stimulus visibility.     

Does matching of internal and external facial features depend on orientation and viewpoint?

Although it is recognized that external (hair, head and face outline, ears) and internal (eyes, eyebrows, nose, mouth) features contribute differently to face recognition it is unclear whether both feature classes predominately stimulate different sensory pathways. We employed a sequential speed-matching task to study face perception with internal and external features in the context of intact faces, and at two levels of contextual congruency. Both internal and external features were matched faster and more accurately in the context of totally congruent/incongruent facial stimuli compared to just featurally congruent/incongruent faces. Matching of totally congruent/incongruent faces was not affected by the matching criteria, but was strongly modulated by orientation and viewpoint. On the contrary, matching of just featurally congruent/incongruent faces was found to depend on the feature class to be attended, with strong effects of orientation and viewpoint only for matching of internal features, but not of external features. The data support the notion that different processing mechanisms are involved for both feature types, with internal features being handled by configuration sensitive mechanisms whereas featural processing modes dominate when external features are the focus.     

Adults' versus children's performance on the Stroop task: Interference and facilitation

Stroop tasks (Stroop, 1935) present stimuli having two dimensions, and participants respond to one dimension whilst ignoring the other. The two dimensions are made congruent, incongruent or neutral with respect to one another. Many claim that ‘Stroop interference’ is higher in children than in adults. However, taking interference as the difference between the incongruent condition and the neutral condition, with interference within the congruent condition itself termed the ‘incongruity effect’ then surprisingly few studies directly address this issue. Also, there is recent debate as to whether the ‘facilitation effect’ (the contrast between the congruent and neutral conditions) is just the opposite of interference. The present investigation (N = 31) concerned a direct comparison between children and adults. Although the incongruity effect reduced with age, interference did not. However, facilitation was far higher in children than in adults. The groups' opposite facilitation/interference asymmetry was used to examine the recent claim that these derive from inadvertent word‐reading and suppression of semantic activation, respectively; rather than solely from the latter.     

Mixed emotions: holistic and analytic perception of facial expressions

In the face literature, it is debated whether the identification of facial expressions requires holistic (i.e., whole face) or analytic (i.e., parts-based) information. In this study, happy and angry composite expressions were created in which the top and bottom face halves formed either an incongruent (e.g., angry top + happy bottom) or congruent composite expression (e.g., happy top + happy bottom). Participants reported the expression in the target top or bottom half of the face. In Experiment 1, the target half in the incongruent condition was identified less accurately and more slowly relative to the baseline isolated expression or neutral face conditions. In contrast, no differences were found between congruent and the baseline conditions. In Experiment 2, the effects of exposure duration were tested by presenting faces for 20, 60, 100 and 120 ms. Interference effects for the incongruent faces appeared at the earliest 20 ms interval and persisted for the 60, 100 and 120 ms intervals. In contrast, no differences were found between the congruent and baseline face conditions at any exposure interval. In Experiment 3, it was found that spatial alignment impaired the recognition of incongruent expressions, but had no effect on congruent expressions. These results are discussed in terms of holistic and analytic processing of facial expressions.     

Mixed emotions: Holistic and analytic perception of facial expressions

In the face literature, it is debated whether the identification of facial expressions requires holistic (i.e., whole face) or analytic (i.e., parts-based) information. In this study, happy and angry composite expressions were created in which the top and bottom face halves formed either an incongruent (e.g., angry top + happy bottom) or congruent composite expression (e.g., happy top + happy bottom). Participants reported the expression in the target top or bottom half of the face. In Experiment 1, the target half in the incongruent condition was identified less accurately and more slowly relative to the baseline isolated expression or neutral face conditions. In contrast, no differences were found between congruent and the baseline conditions. In Experiment 2, the effects of exposure duration were tested by presenting faces for 20, 60, 100 and 120 ms. Interference effects for the incongruent faces appeared at the earliest 20 ms interval and persisted for the 60, 100 and 120 ms intervals. In contrast, no differences were found between the congruent and baseline face conditions at any exposure interval. In Experiment 3, it was found that spatial alignment impaired the recognition of incongruent expressions, but had no effect on congruent expressions. These results are discussed in terms of holistic and analytic processing of facial expressions.     

Keeping Simon simple: Examining the relationship between sequential modulations and feature repetitions with two stimuli, two locations and two responses

The present study examined performance across three two-choice tasks that used the same two stimuli, the same two stimulus locations, and the same two responses to determine how task demands can alter the Simon Effect, its distribution across reaction time, and its sequential modulation. In two of the tasks, repetitions of stimulus features were not confounded with sequences of congruent and incongruent trials. This attribute allowed us to investigate the sequential modulation of the Simon Effect in a two-choice task while equalizing the occurrence of feature repetitions. All tasks showed a similar sequential modulation, suggesting that it is not driven by feature repetitions. Moreover, distributional analyses revealed that the advantage for congruent trials decreased as reaction time increased similarly following congruent and incongruent trials. Finally, a large increase in RT was observed when repeated responses were made to novel stimuli and when novel responses were made to repeated stimuli. This effect also showed a sequential modulation regardless of whether the stimulus repeated. The findings suggest that, even in two-choice tasks, response selection is mediated by complex, dynamic representations that encode abstract properties of the task rather than just simple features.     

Sad or fearful? The influence of body posture on adults’ and children’s perception of facial displays of emotion

The current research investigated the influence of body posture on adults' and children's perception of facial displays of emotion. In each of two experiments, participants categorized facial expressions that were presented on a body posture that was congruent (e.g., a sad face on a body posing sadness) or incongruent (e.g., a sad face on a body posing fear). Adults and 8-year-olds made more errors and had longer reaction times on incongruent trials than on congruent trials when judging sad versus fearful facial expressions, an effect that was larger in 8-year-olds. The congruency effect was reduced when faces and bodies were misaligned, providing some evidence for holistic processing. Neither adults nor 8-year-olds were affected by congruency when judging sad versus happy expressions. Evidence that congruency effects vary with age and with similarity of emotional expressions is consistent with dimensional theories and "emotional seed" models of emotion perception.     

Sequential congruency effects: disentangling priming and conflict adaptation

Responding to the color of a word is slower and less accurate if the word refers to a different color (incongruent condition) than if it refers to the same color (congruent condition). This phenomenon, known as the Stroop effect, is modulated by sequential effects: it is bigger when the current trial is preceded by a congruent condition than by an incongruent one in the previous trial. Whether this phenomenon is due to priming mechanisms or to cognitive control is still debated. To disentangle the contribution of priming with respect to conflict adaptation mechanisms in determining sequential effects, two experiments were designed here with a four-alternative forced choice (4-AFC) Stroop task: in the first one only trials with complete alternations of features were used, while in the second experiment all possible types of repetitions were presented. Both response times (RTs) and errors were evaluated. Conflict adaptation effects on RTs were limited to congruent trials and were exclusively due to priming: they disappeared in the priming-free experiment and, in the second experiment, they occurred in sequences with feature repetitions but not in complete alternation sequences. Error results, instead, support the presence of conflict adaptation effects in incongruent trials. In priming-free sequences (Experiment 1 and complete alternation sequences of Experiment 2) with incongruent previous trials there was no error Stroop effect, while this effect was significant with congruent previous trials. These results indicate that cognitive control may modulate performance above and beyond priming effects.     

Developmental changes in the control of saccadic eye movements in response to directional eye gaze and arrows

We investigated developmental differences in oculomotor control between 10-year-old children and adults using a central interference task. In this task, the colour of a fixation point instructed participants to saccade either to the left or to the right. These saccade directions were either congruent or incongruent with two types of distractor cue: either the direction of eye gaze of a centrally presented schematic face, or the direction of arrows. Children had greater difficulties inhibiting the distractor cues than did adults, which revealed itself in longer saccade latencies for saccades that were incongruent with the distractor cues as well as more errors on these incongruent trials than on congruent trials. Counter to our prediction, in terms of saccade latencies, both children and adults had greater difficulties inhibiting the arrow than the eye gaze distractors.     

Developmental changes in the control of saccadic eye movements in response to directional eye gaze and arrows

We investigated developmental differences in oculomotor control between 10-year-old children and adults using a central interference task. In this task, the colour of a fixation point instructed participants to saccade either to the left or to the right. These saccade directions were either congruent or incongruent with two types of distractor cue: either the direction of eye gaze of a centrally presented schematic face, or the direction of arrows. Children had greater difficulties inhibiting the distractor cues than did adults, which revealed itself in longer saccade latencies for saccades that were incongruent with the distractor cues as well as more errors on these incongruent trials than on congruent trials. Counter to our prediction, in terms of saccade latencies, both children and adults had greater difficulties inhibiting the arrow than the eye gaze distractors.     

Conflict-induced perceptual filtering

In a variety of conflict paradigms, target and distractor stimuli are defined in terms of perceptual features. Interference evoked by distractor stimuli tends to be reduced when the ratio of congruent to incongruent trials is decreased, suggesting conflict-induced perceptual filtering (i.e., adjusting the processing weights assigned to stimuli associated with the target and with the distractor features). In search of evidence for such a mechanism, we administered a flanker task, in which targets and distractors were defined in terms of stimulus location (Experiment 1) or color (Experiment 2). The efficiency of processing stimuli associated with target and distractor features was assessed in intermixed trials of a visual search task, in which a target had to be detected irrespective of these features. In both experiments search times were shorter for stimuli associated with the target feature than with the distractor feature of the flanker task. This effect was increased under conditions of a reduced congruent/incongruent ratio, thereby providing evidence for conflict-dependent perceptual filtering.     

Prior knowledge and subtyping effects in children's category learning

Two experiments examined how 5- and 10-year-old children revise their category representations when exposed to exemplars that are congruent or incongruent with existing knowledge. During training children were presented with exemplars containing features that were congruent or incongruent with children's social stereotypes together with a stereotype-neutral feature. In the knowledge-subtyping condition this neutral feature predicted the stereotype-congruence of the other features. In the knowledge-standard condition the neutral feature was uncorrelated with stereotype-congruence. At test children made judgements about feature co-occurrence within the learned category. In each experiment these judgements were influenced by both stereotypical beliefs and exemplar observation. Stereotypical beliefs, however, had a greater influence on co-occurrence judgements in the knowledge-subtyping than in the standard conditions. In Experiment 2 these effects were shown to generalize to judgements about features that were not presented during training. These results challenge current models of knowledge-based categorization by showing that exemplar structure determines whether novel exemplar features are incorporated into category representations.     

情境特异比例一致变化对冲突效应的影响

采用Hedge和Marsh任务与比例一致性操纵相结合,分别以刺激的空间位置和形状作为比例一致操纵的情境线索,考察刺激-反应联结学习与注意调节在比例一致效应中的作用。结果发现,在情境比例一致操纵下,冲突效应的效应量受到比例一致操纵的影响产生反转。表明刺激-反应联结学习在情境特异比例一致效应中起到主要作用。     

Gradual proportion congruent effects in the absence of sequential congruent effects

In perceptual filtering tasks, congruency effects vary as a function of proportion congruent (PC), with smaller congruency effects when congruent trials are rare than when they are frequent. This effect is typically larger with extreme differences between high and low proportion congruent conditions (e.g., 80% congruent–20% incongruent) than with intermediate differences (e.g., 60% congruent–40% incongruent; Logan & Zbofroff, 1979; Blais & Bunge, 2010). Some authors have claimed that both PC effects can be explained in terms of the same reactive cognitive control mechanism that is responsible for sequential congruency (SC) effects (e.g., Botvinick, Braver, Barch, Carter, & Cohen, 2001). In fact, in most previous studies there was a systematic confounding between proportion congruent and the proportion of transitions involving an incongruent trial followed by another incongruent trial. In the present study we eliminated this confound and tested directly whether PC effects can still be measured in the absence of SC effects. Once confirmed, we studied the properties of this pure form of PC effect, in particular whether it is conflict-type specific or general, and whether it decreases gradually as a function of changes in proportion congruency (80% vs. 70% vs. 60%). Our results showed significant PC effects in the absence of SC effects, which replicates our previous findings (Torres-Quesada, Milliken, Lupiáñez, & Funes, 2014), and PC effects that can be conflict-type general or specific, depending on the nature of conflict type where they were produced. Importantly, the congruency effect was modulated by the level of proportion congruent, decreasing systematically as the absolute percentage of incongruent trials decreases.     

The context congruency effect is face specific

There is evidence that faces are processed by specialized and independent modules that treat them as global configurations, or wholes (Axelrod and Yovel, 2010, Kanwisher et al., 1997). The holistic nature of face perception has been demonstrated with several experimental paradigms designed to examine whether facial parts interact, or are accessed independently. A recently introduced paradigm (Meinhardt-Injac, Persike, & Meinhardt, 2010) measures the strength of contextual interaction among internal and external facial features in congruent and incongruent target/no-target relationships. For this paradigm it is shown that the context congruency effect is indeed face specific: A strong and asymmetric contextual interaction of the inner and the outer stimulus regions exists for faces, but is absent for watches, which represent a non-facial object class with a comparable inner/outer object structure.     

Attentional control adjustments in Eriksen and Stroop task performance can be independent of response conflict

In the Eriksen flanker and colour-word Stroop tasks, the response time (RT) difference between incongruent and congruent trials is smaller following incongruent trials than following congruent trials: the “Gratton effect” (Gratton, Coles, & Donchin, 1992). According to the prevailing conflict-monitoring theory (Botvinick, Braver, Barch, Carter, & Cohen, 2001), the Gratton effect reflects attentional control adjustment following response conflict on incongruent trials. However, because previous studies compared incongruent and congruent trials, it remains unclear to what extent the Gratton effect is driven by incongruent rather than congruent trials. To resolve this issue, we included neutral trials in addition to incongruent and congruent trials in the Eriksen (Experiment 1) and Stroop (Experiment 2) tasks. Participants responded manually and vocally in both tasks. Moreover, we assessed responding to Stroop stimuli that were preceded by neutral cues or by incongruent- or congruent-predicting cues (Experiment 3). In all three experiments, the RT difference between incongruent and congruent trials was larger for postcongruent trials than for postincongruent and postneutral trials. These findings suggest that control adjustments can be independent of response conflict, challenging conflict-monitoring theory.     

Neural processing of intentional biological motion in unaffected siblings of children with autism spectrum disorder: An fMRI study

Despite often showing behaviorally typical levels of social cognitive ability, unaffected siblings of children with autism spectrum disorder have been found to show similar functional and morphological deficits within brain regions associated with social processing. They have also been reported to show increased activation to biological motion in these same regions, such as the posterior superior temporal sulcus (pSTS), relative to both children with autism and control children. It has been suggested that this increased activation may represent a compensatory reorganization of these regions as a result of the highly heritable genetic influence of autism. However, the response patterns of unaffected siblings in the domain of action perception are unstudied, and the phenomenon of compensatory activation has not yet been replicated. The present study used functional magnetic resonance imaging to determine the neural responses to intentional biological actions in 22 siblings of children with autism and 22 matched controls. The presented actions were either congruent or incongruent with the actor’s emotional cue. Prior studies reported that typically developing children and adults, but not children with autism, show increased activation to incongruent actions (relative to congruent), within the pSTS and dorsolateral prefrontal cortex. We report that unaffected siblings did not show a compensatory response, or a preference for incongruent over congruent trials, in any brain region. Moreover, interaction analyses revealed a sub-region of the pSTS in which control children showed an incongruency preference to a significantly greater degree than siblings, which suggests a localized deficit in siblings. A sample of children with autism also did not show differential activation in the pSTS, providing further evidence that it is an area of selective disruption in children with autism and siblings. While reduced activation to both conditions was unique to the autism sample, lack of differentiation to incongruent and congruent intentional actions was common to both children with ASD and unaffected siblings.     

Holistic face processing is mature at 4 years of age: evidence from the composite face effect

Although it is acknowledged that adults integrate features into a representation of the whole face, there is still some disagreement about the onset and developmental course of holistic face processing. We tested adults and children from 4 to 6 years of age with the same paradigm measuring holistic face processing through an adaptation of the composite face effect [Young, A. W., Hellawell, D., & Hay, D. C. (1987). Configurational information in face perception. Perception, 16, 747-759]. In Experiment 1, only 6-year-old children and adults tended to perceive the two identical top parts as different, suggesting that holistic face processing emerged at 6 years of age. However, Experiment 2 suggested that these results could be due to a response bias in children that was cancelled out by always presenting two faces in the same format on each trial. In this condition, all age groups present strong composite face effects, suggesting that holistic face processing is mature as early as after 4 years of experience with faces.