Visual-touch perceptual equivalence for shape information in children and adults

Although there has been substantial developmental research which has compared shape information processing performance under visual and touch conditions, there has been little work that bears on the shape attributes that are routinely employed, or on the similarity between shape attributes employed by adults and those employed by children. The present research was carried out to investigate the visual-touch perceptual equivalence of young children, using multidimensional scaling techniques, and to compare the visual and touch perceptual structures of this age group with those of adults. The results provide evidence for adult-like perceptions of shape among 6-year-olds, in terms of both the patterns of interstimulus similarities and the shape attributes attended to by children using each modality. In addition, it was found that children have somewhat more visual-touch perceptual equivalence than adults do.     

A common perceptual parameter for stair climbing for children,young and old adults

In this paper we examine whether a common perceptual parameter is available for guiding old adults, young adults and children in climbing the highest stair mountable in a bipedal fashion. Previous works have shown that the ratio between the height of the stair and the hip height was the body-scaled invariance adopted as information for selecting the highest stair by young adults [Journal of Experimental Psychology: Human Perception and Performance 10 (1984) 683-703] but not by older adults [Journal of Experimental Psychology: Human Perception and Performance 3 (1992) 691-697]. Indeed, for older adults additional bio-mechanical parameters needed to be added to the model due to their decrease in leg strength and flexibility.Up to now, no perceptual invariant has been identified yet for determining the relevant information used for guiding the stair climbing action for normal healthy people. We propose a new parameter as the angle defined by the ratio between the height of the stair and the distance taken from the feet to the top edge of the stair before the initiation of the movement. We show that this angle is the same for children, young adults and older adults despite the different kinematics of the motion, the anthropometrics and the skill ability exhibit by the participants. In summary we show that even when the climbability judgments, based on the simple ratio leg length-stair height, are influenced by differences in age, participants use a common perceptual variable when they are coordinating their stair climbing action.     

Similarities and differences in the perceptual structure of facial expressions of children and adults

We explored the perceptual structure of facial expressions of six basic emotions, varying systematically in intensity, in adults and children aged 7 and 14 years. Multidimensional scaling suggested that three- or four-dimensional structures were optimal for all groups. Two groups of adults demonstrated nearly identical structure, which had dimensions representing pleasure, potency, arousal, and intensity, despite the fact that one group was tested with a child-friendly “odd-man-out” paradigm and the other group was tested with a conventional similarity-rating paradigm. When tested with the odd-man-out paradigm, the 7-year-olds showed systematic structure, which differed from that of adults in both the meaning of some dimensions and the proximities among some of the expression categories. When tested with similarity judgments, the 14-year-olds showed an adult-like pattern on all measures except that their similarity judgments were more influenced by physical differences than were those of adults. We conclude that an adult-like representation of facial expressions develops slowly during childhood.     

Exploring the perceptual spaces of faces, cars and birds in children and adults

While much developmental research has focused on the strategies that children employ to recognize faces, less is known about the principles governing the organization of face exemplars in perceptual memory. In this study, we tested a novel, child-friendly paradigm for investigating the organization of face, bird and car exemplars. Children ages 3-4, 5-6, 7-8, 9-10, 11-12 and adults were presented with 50/50 morphs of typical and atypical face, bird and car parent images. Participants were asked to judge whether the 50/50 morph more strongly resembled the typical or the atypical parent image. Young and older children and adults showed a systematic bias to the atypical faces and birds, but no bias toward the atypical cars. Collectively, these findings argue that by the age of 3, children encode and organize faces, birds and cars in a perceptual space that is strikingly similar to that of adults. Category organization for both children and adults follows Krumhansl's (1978) distance-density principle in which the similarity between two exemplars is jointly determined by their physical appearance and the density of neighboring exemplars in the perceptual space.     

Priming effects in perceptual classification

Priming stimuli that spatially flank a fixated target stimulus may cause either facilitation or interference with target classification, depending on experimental context. Two experiments demonstrated distinct effects of response compatibility and semantic congruity between flankers and target. Response competition occurred when targets were flanked by context stimuli associated with the opposite response, but this effect diminished when the target was delayed relative to the flankers. Facilitative priming by response-compatible flankers, in contrast, required prior exposure of the flankers, and was strongly influenced by the semantic congruity of flankers and targets. These differing time courses suggest that perceptual priming encompasses a variety of distinct underlying cognitive and motor events.     

Tests of an exemplar model for relating perceptual classification and recognition memory

Experiments were conducted in which Ss made classification, recognition, and similarity judgments for 34 schematic faces. A multidimensional scaling (MDS) solution for the faces was derived on the basis of the similarity judgments. This MDS solution was then used in conjunction with an exemplar-similarity model to accurately predict Ss' classification and recognition judgments. Evidence was provided that Ss allocated attention to the psychological dimensions differentially for classification and recognition. The distribution of attention came close to the ideal-observer distribution for classification, and some tendencies in that direction were observed for recognition. Evidence was also provided for interactive effects of individual exemplar frequencies and similarities on classification and recognition, in accord with the predictions of the exemplar model. Unexpectedly, however, the frequency effects appeared to be larger for classification than for recognition.     

The perceptual classification of speech

By employing new methods of analysis to the physical signal, a number of researchers have provided evidence which suggests that there may be invariant acoustic cues which serve to identify the presence of particular phonetic segments (e.g., Kewley-Port, 1980; Searle, Jacobson, & Rayment, 1979; Stevens & Blumstein, 1978. Whereas previous studies have focused upon the existence of invariant properties present in the physical stimulus, the present study examines the existence of any invariant information available in the psychological stimulus. For this purpose, subjects were asked to classify either a series of full-CV syllables ([bi], [bε], [bo], [??], [di], [d∈], [do], [??]) or one of two series of chirp stimuli consisting of information available in the first 30 meec of each syllable. The full-formant chirp stimuli consisted of the first 30 msec of each syllable, whereas the two-formant chirps were composed of the first 30 msec of only the second and third formants. The object of the present study was to determine whether or not there was sufficient information available in either the full- or two formant chirp series to allow subjects to group the stimuli into two classes corresponding to the identity of the initial consonant of the syllables (i.e., [b], or [d]). A series of classification tasks were used, ranging from a completely free sorting task to a perceptual learning task with experimenter-imposed classifications. The results suggest that there is information available in the full-formant chirps, but not in the two-formant chirps, which allows subjects to group the sounds into classes corresponding to the identity of the initial consonant sounds.     

A model of unidimensional perceptual matching

Faster same than different judgments typically are obtained when two letters are compared. When two tones that might differ only on frequency are compared, however, same judgments typically are slower than different judgments. A uniprocessor, unidimensional model, based on Krueger's noisy-operator theory, was fitted satisfactorily to data from four published studies of tone comparison. The model predicts faster response time on different judgments because of heterogeneity of difference. Because the second tone in a pair typically may be either higher or lower in frequency than the first, there will be a greater variety of perceived difference counts on different pairs than on same pairs. As a result, a large difference count will be decisive and will lead to an immediate "different" response, because it can be produced only by a different pair, whereas a small difference count will not be so decisive because it can be produced by either a same or a different pair. Consequently, there generally will be more rechecking on same than different pairs, and thus longer RT on same pairs.     

A diffusion model of perceptual memory

A model is presented of the perceptual process through which an observer compares two consecutively observed stimuli. Emphasis is placed on the marmer in which a memory of the first stimulus is maintained until the comparison stimulus is observed. It is argued that the role of this perceptual memory process provides the primary distinction between detection and recognition tasks. Two experiments are reported: an experiment in which the observer is asked to judge the similarity in position of two points of light presented serially in a dark room; and an experiment in which the observer judges the similarity in loudness of two serially presented tones. The visual experiment is discussed in relation to the analysis of autokinesis and involuntary eye movements, while the auditory experiment is shown to have special relevance to the issue of time-order errors.     

A test of the regulatory fit hypothesis in perceptual classification learning

This article builds a bridge between research on regulatory focus in motivation and classification learning. It tests the hypothesis that a fit between the situational regulatory focus and the reward structure of the task leads to greater cognitive flexibility than does a mismatch between situational focus and the reward structure and that the fit between the regulatory-focus-induced processing characteristics and the nature of the environment influences performance. In Experiment 1, we used a classification task for which cognitive flexibility should be advantageous and examined both gains (Experiment 1A) and losses (Experiment 1B) reward structures. In Experiments 2 and 3, we used a classification task for which cognitive flexibility should be disadvantageous. In Experiment 2, we used a gains reward structure, and in Experiment 3, we used a losses reward structure. As was predicted, when cognitive flexibility was advantageous, the participants in a regulatory fit showed faster learning and more quickly shifted toward the optimal response strategy. Also as was predicted, when cognitive flexibility was disadvantageous, the participants in a regulatory mismatch showed faster learning and more quickly shifted toward the optimal response strategy. Implications for current theories of motivation and classification learning are discussed.     

Priming and stimulus-response learning in perceptual classification tasks

Participants often respond more quickly and more accurately to a repeated stimulus compared to a non-repeated one, a phenomenon known as repetition priming. In semantic classification tasks priming appears to be largely attributable to the learning of stimulus-decision and stimulus-response associations, which allow participants to bypass many of the processes engaged during initial stimulus analysis. The current study tested whether stimulus-response learning plays a similarly dominant role in priming that occurs in perceptual classification tasks. Unfamiliar objects were used as stimuli to reduce the influence of semantic processes on priming and the task switched for all test trials to eliminate stimulus-decision learning. The results showed across-task priming as measured by reaction time facilitation and improved accuracy when the response remained the same during the encoding and test phases. When the response switched, similar levels of reaction time facilitation were observed, but priming as measured by accuracy was significantly reduced and no longer significant. These findings indicate that stimulus-response learning contributes to priming in perceptual classification tasks, but does not play a dominant role. Significant stimulus-level learning that is independent of the task and response also occurs and likely indexes facilitated perceptual processing of the objects.     

A feedback model of perceptual learning and categorization

Top-down, feedback, influences are known to have significant effects on visual information processing. Such influences are also likely to affect perceptual learning. This paper employs a computational model of the cortical region inter-actions underlying visual perception to investigate possible influences of top-down information on learning. The results suggest that feedback could bias the way in which perceptual stimuli are categorized and could also facilitate the learning of subordinate level representations suitable for object identification and perceptual expertise.     

A unified model for perceptual learning

Perceptual learning in adult humans and animals refers to improvements in sensory abilities after training. These improvements had been thought to occur only when attention is focused on the stimuli to be learned (task-relevant learning) but recent studies demonstrate performance improvements outside the focus of attention (task-irrelevant learning). Here, we propose a unified model that explains both task-relevant and task-irrelevant learning. The model suggests that long-term sensitivity enhancements to task-relevant or irrelevant stimuli occur as a result of timely interactions between diffused signals triggered by task performance and signals produced by stimulus presentation. The proposed mechanism uses multiple attentional and reinforcement systems that rely on different underlying neuromodulators. Our model provides insights into how neural modulators, attentional and reinforcement learning systems are related.     

Preferred perceptual tempo for sound sequences: comparison of adults, children, and infants

Previous motor and perceptual tasks have found optimal processing for sound sequences of a rate of around 600 msec. IOI (Interonset Interval). This zone of optimal processing (the rate at which discrimination is optimal) slows with age and is also found with infants. The current work investigated whether listeners "prefer" sequences at the rate for which they demonstrate optimal processing. In the present study, three experiments were done. Exp. 1 measured tempo preferences in adults who listened to pairs of isochronous sound sequences varying in tempo (from 100- to 1500-msec. IOI) and were required to indicate which they preferred. As expected, highest preferences were expressed for the intermediate tempi, supporting the hypothesis of a zone of preferred tempi comparable to the zone of optimal processing. Moreover, this preference for intermediate tempi was not affected by the temporal context (absence of differences between a fast, a slow, and a wide set of tempi). In Exp. 2, the same procedure was applied to 6- and 10-yr.-olds. Children in both groups had systematic preferences for the fastest tempi within a set, and the older children generally preferred slower sequences. Exp. 3 used a preference paradigm for sound sequences with 4-mo.-old infants, comparing sequences of 100- vs 300-msec. IOI, 300- vs 900-msec. IOI, and 100- vs 900-msec. IOI. No systematic tempo preferences were observed. We conclude that tempo discrimination and tempo preference may have some commonality (perhaps related to a zone of optimal processing), especially in adults, but that they also involve quite distinct processes which undergo different developmental sequences. Whereas adults prefer what they process the best, children prefer what is fastest (and therefore more attention-getting), and we have not been able to detect preferences in infants.     

Development of selective attention: perceptual load influences early versus late attentional selection in children and adults

The moderating effect of perceptual load on visual selective attention was examined in 2 studies. In Study 1, children and young adults searched displays of varying set size flanked by irrelevant distractors. Children's performance was as efficient as adults' under conditions of high but not low loads, suggesting that early selection engages rapidly maturing neural systems and late selection engages later-maturing systems. In Study 2, 4 age groups were tested, and place markers were set at empty locations to examine perceptual grouping effects. Study 1's pattem was replicated in all age groups, with onset of early selection occurring at lower loads for younger children. Overall, children initiated early selection at lower loads to compensate for immature anterior-system interference control processes.     

Cognitive complexity effects in perceptual classification are dissociable

It has been proposed that a procedural-based classification system mediates the learning of information-integration categories, whereas a hypothesis-testing system mediates the learning of rule-based categories. Ashby, Ell and Waldron (2003) provided support for this claim by showing that a button switch introduced during classification transfer adversely affected information-integration but not rule-based performance. Nosofsky, Stanton and Zaki (2005) showed that increasing "cognitive complexity" can lead to button switch costs on rule-based performance. They argue that "cognitive complexity," and not the existence of separable classification systems, accounts for Ashby et al.'s empirical dissociation. The present study shows that experimental manipulations that increase "cognitive complexity" often have dissociable effects on information-integration and rule-based classification that are predicted a priori from the processing characteristics associated with the procedural-based and hypothesis-testing systems. These results suggest that manipulations of "cognitive complexity" can be dissociated, suggesting that "cognitive complexity" in not a unitary construct that affects a single psychological process.     

A Bayesian model for implicit effects in perceptual identification

Retrieving effectively from memory (REM; R. M. Shiffrin & M. Steyvers, 1997), an episodic model of memory, is extended to implicit memory phenomena, namely the perceptual identification studies reported in R. Ratcliff and G. McKoon (1997). In those studies, the influence of prior study was greatest when words were presented most briefly and when forced-choice targets and foils were most similar. R. Ratcliff and G. McKoon use these data to argue against models in which prior study changes a word's representation. A model in which prior study changes a word's representation by adding context information is fit to their data; at test, the model uses a Bayesian decision process to compare the perceptual and context features associated with the test flash to stored traces. The effects of prior study are due to matching extra context information and are larger when alternatives share many features, thereby reducing noise that attenuates these effects.     

Short-term memory for time in children and adults: A behavioral study and a model

This experiment investigated the effect of the short-term retention of duration on temporal discrimination in 5- and 8-year-olds, as well as in adults, by using an episodic temporal generalization task. In each age group, the participants' task was to compare two successive durations (a standard and a comparison duration) separated by a retention interval of 500ms, 5s, or 10s, with the order of presentation of these two durations being counterbalanced. The results revealed a shortening effect for the first presented stimulus in all of the age groups, although this was greater in the younger children, thereby indicating the presence of a negative time-order error. Furthermore, introducing a retention delay between the two durations did not produce a shortening effect but instead flattened the generalization gradient, especially in the younger children. However, this flattening of the generalization gradient with the retention delay was more marked between 500ms and 5s than between 5s and 10s. Thus, retaining the first duration in short-term memory during a task requiring the comparison of two successive durations reduced temporal discrimination accuracy and did so to a greater extent in the younger children.