Developing race categories in infancy via Bayesian face recognition

The other-race effect emerges during infancy following the perceptual narrowing of face recognition. Other-race faces that were previously discriminable in early infancy cannot be distinguished by older infants. I discuss a Bayesian model of this process that posits that the other-race effect may be a consequence of learning to distinguish between intrapersonal variation (changes to face appearance that preserve identity) and extrapersonal variation (changes that do not preserve identity) in a visual environment in which a subset of race categories dominate. I demonstrate that race categories, which I have previously argued are a critical precursor to the emergence of the other-race effect in infancy, are a natural by-product of this model. Perceptual narrowing for race may thus be a natural consequence of visual experience and the estimation of face variability based on a growing number of exemplars. I describe the basic architecture of the model, its applicability to a range of visual learning scenarios, and identify critical choices one faces in applying the model to a specific perceptual task. Despite the success of the model in accounting for these behavioural results, I conclude by identifying important shortcomings of the model and describe important challenges for future efforts to characterize the development of the other-race effect computationally.     

Visual impressions of force exerted by one object on another when the objects do not come into contact

Simple animations in which one object contacts another give rise to visual impressions that the former object causes the outcome for the latter, and that the former object is exerting force on the latter. How does the impression of force relate to the impression of causality? The main aim of this research was to investigate this issue using stimuli in which there is a gap between the objects at closest approach. Delay between the first object stopping and the second object starting to move had a strong effect on reported force impressions, which is consistent with findings of research on the causal impression. However, the reported force impression was little affected by either the size of the gap or the presence and features of an object in the gap, whereas the causal impression was strongly affected by both. The findings support the conclusion that the force impression and the causal impression are distinct components of the visual interpretation of the stimulus.     

Effects of divided attention and social categorization on the own-race bias in face recognition

Perceivers remember own-race faces more accurately than other-race faces (i.e., Own-Race Bias). In the current experiments, we manipulated participants' attentional resources and social group membership to explore their influence on own and other-race face recognition memory. In Experiment 1, Chinese participants viewed own-race and Caucasian faces, and between-subjects we manipulated whether participants attention was divided during face encoding. We found that divided attention eliminated the Own-Race Bias in memory due to a reduction of memory accuracy for own-race faces, implicating that attention allocation plays a role in creating the bias. In Experiment 2, Chinese participants completed an ostensible personality test. Some participants were informed that their personality traits were most commonly found in Caucasian (i.e., other-race) individuals, resulting in these participants sharing a group membership with other-race targets. In contrast, other participants were not told anything about the personality test, resulting in the default own-race group membership. The participants encoded the faces for a subsequent recognition memory test either with or without performing a concurrent arithmetic distracting task. Results showed that other-race group membership and reducing attention during encoding independently eliminated the typical Own-Race Bias in face memory. The implications of these findings on perceptual-expertise and social-categorization models are discussed.     

Perceptual coupling of multiple point-light figures

When confronted with multiple bistable stimuli at the same time, the visual system tends to generate a common interpretation for all stimuli. We exploit this perceptual-coupling phenomenon to investigate the perception of depth in bistable point-light figures. Observers indicate the global depth orientation of simultaneously presented point-light figures while the similarity between the stimuli is manipulated. In a first experiment, a higher occurrence of coupled percepts is found for identical figures, but coupling breaks down when either the movement pattern or both the viewpoint and the phase-relation are changed. A second experiment confirms these results, but also demonstrates that different point-light actions can be subject to perceptual coupling as long as they share the same viewpoint and exhibit equivalent degrees of perceptual ambiguity. The data are consistent with an explanation in terms of differential contributions of stored, view-dependent object and action representations and of an interaction between stages processing local stimulus features. The consequences of these results are discussed in the framework of an explicit model for the perception of depth in biological motion.     

Engaging the motor system with masked orthographic primes: A kinematic analysis

We report two experiments in which participants categorized target words (e.g., BLOOD or CUCUMBER) according to their canonical colour of red or green by pointing to a red square on the left or a green square on the right. Unbeknownst to the participants, the target words were preceded by the prime words “red” or “green”. We found that the curvature of participants’ pointing trajectories was greater following incongruent primes (green–BLOOD) than it was following congruent primes, indicating that individuals initiated a response on the basis of the prime and then corrected that response mid-flight. This finding establishes that the processing of masked orthographic stimuli extends down to include the formulation of an overt manual response.     

Angry at your boss: Who cares? Anger recognition and mediation effectiveness

The key to success for workplace mediators lies in establishing a relationship of understanding, empathy, and trust with the conflicting parties. Literature suggests that the recognition of parties’ emotions by the mediator is essential to obtain such a relation. Although anger is one of the most prevailing emotions in conflict, little is known about how parties react to the experience of anger recognition on the part of the mediator, how this affects their perceptions of mediation effectiveness, and whether this is moderated by the hierarchical position parties occupy. Drawing on theories of power, emotions, and conflict, this study tests the hypothesis that conflicting parties in workplace mediation who experience anger recognition on the part of the mediator perceive the mediation as more effective and that this is more so for subordinates than for supervisors. Data collected in real labour mediations support this. Implications for mediation theory and practice are discussed.     

The role of prior knowledge in error correction for younger and older adults

Previous work has demonstrated that, when given feedback, younger adults are more likely to correct high-confidence errors compared with low-confidence errors, a finding termed the hypercorrection effect. Research examining the hypercorrection effect in both older and younger adults has demonstrated that the relationship between confidence and error correction was stronger for younger adults compared with older adults. However, recent work suggests that error correction is largely related to prior knowledge, while confidence may primarily serve as a proxy for prior knowledge. Prior knowledge generally remains stable or increases with age; thus, the current experiment explored how both confidence and prior knowledge contributed to error correction in younger and older adults. Participants answered general knowledge questions, rated how confident they were that their response was correct, received correct answer feedback, and rated their prior knowledge of the correct response. Overall, confidence was related to error correction for younger adults, but this relationship was much smaller for older adults. However, prior knowledge was strongly related to error correction for both younger and older adults. Confidence alone played little unique role in error correction after controlling for the role of prior knowledge. These data demonstrate that prior knowledge largely predicts error correction and suggests that both older and younger adults can use their prior knowledge to effectively correct errors in memory.     

Age-related changes in deterministic learning from positive versus negative performance feedback

Feedback-based learning declines with age. Because older adults are generally biased toward positive information (“positivity effect”), learning from positive feedback may be less impaired than learning from negative outcomes. The literature documents mixed results, due possibly to variability between studies in task design. In the current series of studies, we investigated the influence of feedback valence on reinforcement learning in young and older adults. We used nonprobabilistic learning tasks, to more systematically study the effects of feedback magnitude, learning of stimulus–response (S–R) versus stimulus–outcome (S–O) associations, and working-memory capacity. In most experiments, older adults benefitted more from positive than negative feedback, but only with large feedback magnitudes. Positivity effects were pronounced for S–O learning, whereas S–R learning correlated with working-memory capacity in both age groups. These results underline the context dependence of positivity effects in learning and suggest that older adults focus on high gains when these are informative for behavior.     

Adult age differences in memory for schema-consistent and schema-inconsistent objects in a real-world setting

The present study examined age-related differences in the inconsistency effect, in which memory is enhanced for schema-inconsistent information compared to schema-consistent information. Young and older adults studied schema-consistent and schema-inconsistent objects in an academic office under either intentional or incidental encoding instructions, and were given two recognition tests either immediately or after 48 hr: A yes/no item recognition test that included modified remember/know judgments and a token recognition test that required determining whether an original object was replaced with a different object with the same name. Young and older adults showed equivalent inconsistency effects in both item and token recognition tests, although older adults reported phenomenologically less rich memories of schema-inconsistent objects relative to young adults. These findings run counter to previous reports suggesting that aging is associated with processing declines at encoding that impair memory for details of schema-inconsistent or distinctive events. The results are consistent with a retrieval-based account in which age-related difficulties in retrieving contextual details can be offset by environmental support.     

Age-related associative deficits and the isolation effect

ABSTRACT

If all but one of the items in a list are similar (e.g., all black except one red), memory for the different item is enhanced (the isolation effect). Older adults generally show similar or smaller isolation effects compared to young adults, which has been attributed to age-related deficits in associative memory whereby older adults are less able to associate an isolated stimulus to its isolating feature. Experiment 1 examined the isolation effect for isolation based on spatial position, modality and color; in Experiment 2, the criterion for isolation was the associative relation between stimuli. The results consistently showed no differences between young and older participants in the magnitude of the isolation effect. Whilst age deficits in associative memory may act to reduce the isolation effect in older adults, age deficits in self-initiated processing and inhibitory functionality may counteract this reduction by enhancing the isolation effect in older adults.