Angela Hayden

Race-based perceptual asymmetries underlying face processing in infancy.

Adults process other-race faces differently than own-race faces. For instance, a single other-race face in an array of own-race faces attracts Caucasians’ attention, but a single own-race face among other-race faces does not. This perceptual asymmetry has been explained by the presence of an other-race feature in other-race faces and its absence in own-race faces; this difference is thought to underlie race-based differences in face processing. We examined the developmental origins of this mechanism in two groups of Caucasian 9-month-olds. Infants in the experimental group exhibited a preference for a pattern containing a single Asian face among seven Caucasian faces over a pattern containing a single Caucasian face among seven Asian faces. This preference was not driven by the majority of elements in the images, because a control group of infants failed to exhibit a preference between homogeneous patterns containing eight Caucasian versus eight Asian faces. The results demonstrate that an other-race face among own-race faces attracts infants’ attention but not vice versa. This perceptual asymmetry suggests that the other-race feature is available to Caucasians by 9 months of age, thereby indicating that mechanisms of specialization in face processing originate early in life.

Infants’ sensitivity to uniform connectedness as a cue for perceptual organization

A new grouping principle, uniform connectedness (UC), has been posited to be a basic organizer of visual pattern information, one that takes precedence over other, more classic grouping principles (Palmer & Rock, 1994), but its ontogenetic origins have not previously been investigated. We examined whether 3- to 4-month-olds and 6- to 7-month-olds utilize UC to organize static two-dimensional displays. Infants habituated to uniformly connected patterns exhibited a novelty preference for disconnected element patterns, whereas those without any habituation failed to exhibit a preference. The results indicate that infants are sensitive to UC as a cue for perceptual organization. Prior studies indicate that some Gestalt principles (e.g., common movement) are functional during the first half year of life, but that other principles (e.g., form similarity) are less readily available. The present finding showing that young infants are sensitive to UC points to the foundational nature of this cue and adds to an emerging body of evidence indicating that at least some of the mechanisms believed to produce perceptual organization in adults are already operational in the first months of life. nt]mis|This research was supported by grants from the National Science Foundation (BCS 0224240) and the National Institute of Child Health and Human Development (HD042451).

Perceptual organization based on illusory regions in infancy

Prior research indicates that, like adults, infants use enclosed regions to group elements. It is not clear whether infants or adults can use regions that have to be inferred from illusory contours to group elements. We examined whether 3- to 4-month-olds use illusory regions to group elements and generalize this organization to novel regions. Infants habituated to pairs of shapes in illusory vertical or horizontal regions subsequently discriminated, in novel regions, pairs of elements that had previously shared a region from pairs of elements that had been in different regions. A control group of infants, who had experienced the same stimuli except for the presence of illusory regions, failed to discriminate between within-region and between-region pairs of stimuli. These results reveal that (1) illusory regions can be used to group elements, (2) perceptual organization is sufficiently developed early in life for 3- to 4-month-olds to group on the basis of ecologically relevant illusory contours, and (3) such grouping in infancy generalizes to novel regions.

What Goes with What? Development of Perceptual Grouping in Infancy

Abstract Pattern perception and organization provide the representations that form the basic processing units in the visual cognition system of adults. This chapter will highlight a line of research investigating the origins and development of such perceptual organization abilities in infants. In particular, the chapter will describe the major theoretical positions on the development of perceptual unit formation and review empirical findings on the operation of a variety of organizational principles that become functional during the first months of life. The results demonstrate that a variety of grouping principles are available for use by infants, although different principles may become functional over different time courses of development, may be governed by different developmental determinants (i.e., maturation vs experience), and not all principles are readily deployed in the manner originally proposed by Gestalt psychologists. The findings also suggest that the principles can yield processing units of an abstract nature and that the operation of the principles can be modulated by top–down influences.

Inference Generation and Story Comprehension Among Children with ADHD

Academic difficulties are well-documented among children with ADHD. Exploring these difficulties through story comprehension research has revealed deficits among children with ADHD in making causal connections between events and in using causal structure and thematic importance to guide recall of stories. Important to theories of story comprehension and implied in these deficits is the ability to make inferences. Often, characters’ goals are implicit and explanations of events must be inferred. The purpose of the present study was to compare the inferences generated during story comprehension by 23 7– to 11-year-old children with ADHD (16 males) and 35 comparison peers (19 males). Children watched two televised stories, each paused at five points. In the experimental condition, at each pause children told what they were thinking about the story, whereas in the control condition no responses were made during pauses. After viewing, children recalled the story. Several types of inferences and inference plausibility were coded. Children with ADHD generated fewer of the most essential inferences, plausible explanatory inferences, than did comparison children, both during story processing and during story recall. The groups did not differ on production of other types of inferences. Group differences in generating inferences during the think-aloud task significantly mediated group differences in patterns of recall. Both groups recalled more of the most important story information after completing the think-aloud task. Generating fewer explanatory inferences has important implications for story comprehension deficits in children with ADHD.

Parts, cavities, and object representation in infancy.

Part representation is not only critical to object perception but also plays a key role in a number of basic visual cognition functions, such as figure-ground segregation, allocation of attention, and memory for shapes. Yet, virtually nothing is known about the development of part representation. If parts are fundamental components of object shape representation early in life, then the infant visual system should give priority to parts over other aspects of objects. We tested this hypothesis by examining whether part shapes are more salient than cavity shapes to infants. Five-month-olds were habituated to a stimulus that contained a part and a cavity. In a subsequent novelty preference test, 5-month-olds exhibited a preference for the cavity shape, indicating that part shapes were more salient than cavity shapes during habituation. The differential processing of part versus cavity contours in infancy is consistent with theory and empirical findings in the literature on adult figure-ground perception and indicates that basic aspects of part-based object processing are evident early in life.

Part perception in infancy: Sensitivity to the short-cut rule

Research indicates that object perception involves the decomposition of images into parts. A critical principle that governs part decomposition by adults is the short-cut rule, which states that, all else being equal, the visual system parses objects using the shortest possible cuts. We examined whether 6.5-month-olds’ parsing of images also follows the short-cut rule. Infants in the experimental conditions were habituated to cross shapes and then tested for their preference between segregated patterns produced using long cuts versus short cuts. Infants in the control conditions were directly tested with the segregated patterns. Infants in the experimental conditions exhibited a greater novelty preference for the long-cut over the short-cut patterns than did those in the control conditions, thereby indicating that they are more likely to segregate cross shapes using short cuts rather than long cuts. This sensitivity to the short-cut rule was evident when two alternative parameters, part area and protrusion, were controlled in Experiments 1 and 2, respectively. Thus, a critical principle that governs part segregation in adulthood is operational by 6.5 months of age.

Transfer of associative grouping to novel perceptual contexts in infancy

Learning can be highly adaptive if associations learned in one context are generalized to novel contexts. We examined the development of such generalization in infancy in the context of grouping. In Experiment 1, 3- to 4-month-olds and 6- to 7-month-olds were habituated to shapes grouped via the organizational principle of common region and were tested with familiar and novel pairs as determined by the principle of proximity. Older infants generalized from common region to proximity, but younger infants did not. Younger infants failed to generalize when the task was easier (Experiment 2), and their failure was not due to inability to group via proximity (Experiment 3). However, in Experiment 4, even younger infants generalized grouping on the basis of connectedness to proximity. Thus, the ability to transfer learned associations of shapes to novel contexts is evident early in life, although it continues to undergo quantitative change during infancy. Moreover, the operation of this generalization mechanism may be induced by means of bootstrapping onto functional organizational principles, which is consistent with a developmental framework in which core processes scaffold learning.

Parts function as perceptual organizational entities in infancy

Both objects and parts function as organizational entities in adult perception. Prior research has indicated that objects affect organization early in life: Infants grouped elements located within object boundaries and segregated them from those located on different objects. Here, we examined whether parts also induce grouping in infancy. Five- and 6.5-month-olds were habituated to two-part objects containing element pairs. In a subsequent test, infants treated groupings of elements that crossed part boundaries as novel, in comparison with groupings that had shared a common part during habituation. In contrast, the same arrangement of elements failed to elicit evidence of grouping in control conditions in which the elements were not surrounded by closed part boundaries. Thus, infants grouped and segregated elements on the basis of part structure. Part-based processing is a key aspect of many theories of perception. The present research adds to this literature by indicating that parts function as organizational entities early in life.