View-invariant object category learning, recognition, and search: how spatial and object attention are coordinated using surface-based attentional shrouds

How does the brain learn to recognize an object from multiple viewpoints while scanning a scene with eye movements? How does the brain avoid the problem of erroneously classifying parts of different objects together? How are attention and eye movements intelligently coordinated to facilitate object learning? A neural model provides a unified mechanistic explanation of how spatial and object attention work together to search a scene and learn what is in it. The ARTSCAN model predicts how an object's surface representation generates a form-fitting distribution of spatial attention, or "attentional shroud". All surface representations dynamically compete for spatial attention to form a shroud. The winning shroud persists during active scanning of the object. The shroud maintains sustained activity of an emerging view-invariant category representation while multiple view-specific category representations are learned and are linked through associative learning to the view-invariant object category. The shroud also helps to restrict scanning eye movements to salient features on the attended object. Object attention plays a role in controlling and stabilizing the learning of view-specific object categories. Spatial attention hereby coordinates the deployment of object attention during object category learning. Shroud collapse releases a reset signal that inhibits the active view-invariant category in the What cortical processing stream. Then a new shroud, corresponding to a different object, forms in the Where cortical processing stream, and search using attention shifts and eye movements continues to learn new objects throughout a scene. The model mechanistically clarifies basic properties of attention shifts (engage, move, disengage) and inhibition of return. It simulates human reaction time data about object-based spatial attention shifts, and learns with 98.1% accuracy and a compression of 430 on a letter database whose letters vary in size, position, and orientation. The model provides a powerful framework for unifying many data about spatial and object attention, and their interactions during perception, cognition, and action.     

What can we learn from toddlers about categorical perception of color? Comments on Goldstein, Davidoff, and Roberson

We comment on Goldstein, Davidoff, and Roberson’s replication and extension (Journal of Experimental Child Psychology, 102, 219-238 [2009]) of our study of the effect of toddlers’ color term knowledge on their categorical perception (CP) of color (Journal of Experimental Child Psychology, 90, 114-141 [2005]). First, we discuss how best to assess color term knowledge when concerned with the effects of language on color CP. A reanalysis of our data indicates that even toddlers who do not know the terms for the relevant focal colors still show CP. Second, we comment on Goldstein and colleagues’ finding of blue-purple CP, as we did, but not of blue-green CP in Himba toddlers. We present contrasting data from Wright (unpublished PhD thesis, University of Surrey, 2006) that demonstrates blue-green CP in Himba toddlers. Finally, we discuss the limitations of the approach taken by all of these investigations and discuss theoretical accounts of the origin and nature of color CP.     

Sound enhances detection of visual target during infancy: a study using illusory contours

In adults, a salient tone embedded in a sequence of nonsalient tones improves detection of a synchronously and briefly presented visual target in a rapid, visually distracting sequence. This phenomenon indicates that perception from one sensory modality can be influenced by another one even when the latter modality provides no information about the judged property itself. However, no study has revealed the age-related development of this kind of cross-modal enhancement. Here we tested the effect of concurrent and unique sounds on detection of illusory contours during infancy. We used a preferential looking technique to investigate whether audio-visual enhancement of the detection of illusory contours could be observed at 5, 6, and 7 months of age. A significant enhancement, induced by sound, of the preference for illusory contours was observed only in the 7-month-olds. These results suggest that audio-visual enhancement in visual target detection emerges at 7 months of age.     

Age-related differences in reaction time task performance in young children

Performance of reaction time (RT) tasks was investigated in young children and adults to test the hypothesis that age-related differences in processing speed supersede a “global” mechanism and are a function of specific differences in task demands and processing requirements. The sample consisted of 54 4-year-olds, 53 5-year-olds, 59 6-year-olds, and 35 adults from Russia. Using the regression approach pioneered by Brinley and the transformation method proposed by Madden and colleagues and Ridderinkhoff and van der Molen, age-related differences in processing speed differed among RT tasks with varying demands. In particular, RTs differed between children and adults on tasks that required response suppression, discrimination of color or spatial orientation, reversal of contingencies of previously learned stimulus-response rules, and greater stimulus-response complexity. Relative costs of these RT task differences were larger than predicted by the global difference hypothesis except for response suppression. Among young children, age-related differences larger than predicted by the global difference hypothesis were evident when tasks required color or spatial orientation discrimination and stimulus-response rule complexity, but not for response suppression or reversal of stimulus-response contingencies. Process-specific, age-related differences in processing speed that support heterochronicity of brain development during childhood were revealed.     

Seeing power in action: The roles of deliberation, implementation, and action in inferences of power

Six experiments investigate the hypothesis that social targets who display a greater action orientation are perceived as having more power (i.e., more control, less dependence, and more influence) than less action-oriented targets. I find evidence that this inference pattern is based on the pervasive belief that individuals with more power experience less constraint and have a greater capacity to act according to their own volition. Observers infer that targets have more power and influence when they exhibit more implementation than deliberation in the process of making decisions in their personal lives (Study 1a), in a public policy context (Study 1b), and in small groups (Study 2). In an organizational context, observers infer that a target who votes for a policy to change from the status quo has more power than a target who votes not to change from the status quo (Study 3). People also infer greater intra-organizational power and higher hierarchical rank in targets who take physical action toward a personal goal than in those who do not (Studies 4-5).     

Who is approachable?

The consequences of social interaction can be variable, sometimes harmful, but often rewarding. The adaptive social perceiver must therefore determine which interactions are worthwhile pursuing and which are not. The present research investigated whether subtle but meaningful differences in facial expressions are perceived in terms of the affordance of approachability. Participants engaged in simulated social encounters with targets displaying enjoyment smiles, non-enjoyment smiles or neutral expressions while fluctuations in their posture were measured. The results indicated systematic differences in perceived approachability as a function of facial expression and target sex. These findings are discussed in terms of the functional coupling between social perception and action with respect to the information that specifies the affordance of approachability.     

Between a rock and a hard place: Damned if you do, damned if you don’t

Individuals are frequently forced to make decisions from among undesirable choice-sets. Raise taxes or cut social services? Lay off workers or go bankrupt? Go deep in debt or forgo a college education? The research presented here suggests that in such situations, decision-makers are often evaluated negatively regardless of the choice they make. In Experiment 1, participants read about a judge deciding which of two seemingly unfit parents to award sole custody in a real-life divorce case. In Experiment 2, participants were led to believe that their partner in the experiment was forced to pick one of two unpleasant tasks for the participant to perform. In both cases, the decision and decision-maker were evaluated negatively regardless of the alternative chosen–and regardless of the fact that they were the only options in the choice-set. Discussion focuses on the source, scope, and consequences of this phenomenon.     

Do local properties function as cues for musical key perception?1

Abstract: A global property (i.e., pitch set) of a melody appears to serve as a primary cue for key identification. Previous studies have proposed specific local properties in a melody (e.g., the augmented fourth, the perfect fifth, etc.) that may function as further cues. However, the role of the latter in key identification is controversial. The present study was designed to investigate what kinds of local properties, if any, function as reliable cues for key identification. Listeners were asked to identify keys for 450 melodies that consisted of the same pitch set, but which differed in sequential constraints. Using multiple discriminant analyses, we evaluated relative contributions of as many kinds of local properties as possible (e.g., single intervals, single pitch classes in each sequential position, etc.). The results showed that, except for the pitch class of the final tone, for which interpretation should be taken cautiously, none of the specific local properties examined contributed significantly to key identification. This finding suggests that, contrary to prior findings, key identification is derived from unidentified properties other than the specific local properties.     

Culture and visual perception: Does perceptual inference depend on culture?1,2

Abstract: Some perceptual cues carry information about the overall pattern of an object (holistic cues), whereas others carry information about the distinct parts of an object (part cues). Drawing on recent work on culture and cognition, the authors predicted that people with European‐American cultural backgrounds would be more capable of using part cues in perceptual inference than those with Asian backgrounds. No such cross‐cultural difference was expected for the ability to use holistic cues. In two studies, participants were presented with either one of the two types of cues and asked to infer the identity of the original objects. As predicted, in the part‐cue condition European‐American participants performed better than did Japanese (Study 1) and Asian‐American participants (Study 2). Also as predicted, there was no cultural difference in the holistic‐cue condition. The results were interpreted with reference to other related studies documenting reliable cross‐cultural differences in cognition.     

A pox on the mind: Disjunction of attention and memory in the processing of physical disfigurement

The unfavorable treatment of people with physical disfigurements is well-documented, yet little is known about basic perceptual and cognitive responses to disfigurement. Here, we identify a specialized pattern of cognitive processing consistent with the hypothesis that disfigurements act as heuristic cues to contagious disease. Disfigurements are often invariant across time and difficult to conceal, and thus observers can detect the presence of such cues without necessarily remembering the particular individuals bearing these cues. Indeed, despite the fact that disfigured faces were especially likely to hold disease-sensitive perceivers’ attention (Study 1), disfigured individuals were often confused with one another and thus not well remembered later (Study 2), revealing a disjunction of the typical relationship between elevated attention and elevated memory. We discuss the implications of our results for stigmatization of people with and without physical abnormalities and suggest the possibility that cognitive mechanisms for processing social information may be functionally tuned to the variant nature of important cues.