Preschool children's proto-episodic memory assessed by deferred imitation

In two experiments, both employing deferred imitation, we studied the developmental origins of episodic memory in two- to three-year-old children by adopting a “minimalist” view of episodic memory based on its What–When–Where (“WWW”: spatiotemporal plus semantic) content. We argued that the temporal element within spatiotemporal should be the order/simultaneity of the event elements, but that it is not clear whether the spatial content should be egocentric or allocentric. We also argued that episodic recollection should be configural (tending towards all-or-nothing recall of the WWW elements). Our first deferred imitation experiment, using a two-dimensional (2D) display, produced superior-to-chance performance after 2.5 years but no evidence of configural memory. Moreover, performance did not differ from that on a What–What–What control task. Our second deferred imitation study required the children to reproduce actions on an object in a room, thereby affording layout-based spatial cues. In this case, not only was there superior-to-chance performance after 2.5 years but memory was also configural at both ages. We discuss the importance of allocentric spatial cues in episodic recall in early proto-episodic memory and reflect on the possible role of hippocampal development in this process.     

Differential effects of visual context on pattern discrimination by pigeons (Columba livia) and humans (Homo sapiens)

Three experiment examined the role of contextual information during line orientation and line position discriminations by pigeons (Columba livia) and humans (Homo sapiens). Experiment 1 tested pigeons' performance with these stimuli in a target localization task using texture displays. Experiments 2 and 3 tested pigeons and humans, respectively, with small and large variations of these stimuli in a same-different task. Humans showed a configural superiority effect when tested with displays constructed from large elements but not when tested with the smaller, more densely packed texture displays. The pigeons, in contrast, exhibited a configural inferiority effect when required to discriminate line orientation, regardless of stimulus size. These contrasting results suggest a species difference in the perceptionand use of features and contextual information in the discrimination of line information.     

The role of attention in processing configural and shape information in 3-D novel objects

Recent research suggests that there is an advantage for processing configural information in scenes and objects. The purpose of this study was to investigate the extent to which attention may account for this configural advantage. In Experiment 1, we found that cueing the location of change in single object displays improved detection performance for both configural and shape changes, yet cueing attention away from the location of change was detrimental only for shape change detection. A configural advantage was present for each cueing condition. Experiments 2A and 2B examined whether the configural advantage persisted in conditions where attention was distributed more widely, using a visual search paradigm. Although searches for configural changes were faster than those for shape changes across all set sizes, both types of information appeared to be processed with similar efficiency. Overall, these results suggest that the configural advantage is independent of the location or distribution of visual attention.     

Configural face processing develops more slowly than featural face processing

Expertise in face processing takes many years to develop. To determine the contribution of different face-processing skills to this slow development, we altered a single face so as to create sets of faces designed to measure featural, configural, and contour processing. Within each set, faces differed only in the shape of the eyes and mouth (featural set), only in the spacing of the eyes and mouth (spacing set), or only in the shape of the external contour (contour set). We presented adults, and children aged 6, 8, and 10 years, with pairs of upright and inverted faces and instructed them to indicate whether the two faces were the same or different. Adults showed a larger inversion effect for the spacing set than for the featural and external contour sets, confirming that the spacing set taps configural processing. On the spacing set, all groups of children made more errors than adults. In contrast, on the external contour and featural sets, children at all ages were almost as accurate as adults, with no significant difference beginning at age 6 on the external contour set and beginning at age 10 on the featural set. Overall, the results indicate that adult expertise in configural processing is especially slow to develop.     

Spatial correspondence and relation correspondence: grouping factors that influence perception of the Ternus display

We cite two different perceptual-correspondence principles whose emphasis can help to disambiguate the otherwise ambiguous Ternus display in apparent movement (a display that can alternately be seen in one of two possible configurations). One of these principles is spatial correspondence, which emphasizes the maintenance of similar stimulus elements in given locations over time. The other principle is relation correspondence, which emphasizes the maintenance of the inter-organization of stimulus elements across frames. Each of four experiments reported here made use of a different stimulus feature (eg element color or element texture) to emphasize these different correspondence principles in Ternus displays. As predicted, an emphasis upon spatial correspondence resulted in an increase in reports of element movement compared to a featureless control condition. Emphasis on relation correspondence resulted in an increase in reports of group movement. Extensions and limitations of the use of these principles to explain apparent movement are discussed.     

Configural features in the context of upright and inverted faces

When faces are turned upside down, recognition is known to be severely disrupted. This effect is thought to be due to disruption of configural processing. Recently, Leder and Bruce (2000, Quarterly Journal of Experimental Psychology A 53 513-536) argued that configural information in face processing consists at least partly of locally processed relations between facial elements. In three experiments we investigated whether a local relational feature (the interocular distance) is processed differently in upside-down versus upright faces. In experiment 1 participants decided in which of two sequentially presented photographic faces the interocular distance was larger. The decision was more difficult in upside-down presentation. Three different conditions were used in experiment 2 to investigate whether this deficit depends upon parts of the face beyond the eyes themselves; displays showed the eye region alone, the eyes and nose, or the eyes and nose and mouth. The availability of additional features did not interact with the inversion effect which was observed strongly even when the eyes were shown in isolation. In experiment 3 all eyes were turned upside down in the inverted face condition as in the Thatcher illusion (Thompson, 1980 Perception 9 483-484). In this case no inversion effect was found. These results are in accordance with an explanation of the face-inversion effect in which the disruption of configural facial information plays the critical role in memory for faces, and in which configural information corresponds to spatial information that is processed in a way which is sensitive to local properties of the facial features involved.     

Integration of information from multiple element displays

This experiment examined the processing of information from multiple element visual displays, using techniques derived from the theory of signal detectability. The method allows one to specify how observers integrate information from individual elements of a display. The experiment tested numerical and graphical displays having different display sizes, durations, and arrangements of elements. Observer performance increased with the number, m, of display elements, but at less than the ideal √m rate. Observer performance was consistent with a model of information integration constrained by internal noise. Linear arrays of elements resulted in better performance than did square arrays. Graphically coded elements resulted in better performance than did numerical elements. Observer decision weighting of element information from graphical displays was approximately uniform across spatial position, but the weighting of information from numerical displays was concentrated on elements near the fixation point.     

An own-race advantage for components as well as configurations in face recognition

The own-race advantage in face recognition has been hypothesized as being due to a superiority in the processing of configural information for own-race faces. Here we examined the contributions of both configural and component processing to the own-race advantage. We recruited 48 Caucasian participants in Australia and 48 Chinese participants in Hong Kong, and had them study Caucasian and Chinese faces. After study, they were shown old faces (along with distractors) that were either blurred (isolating configural processing), in which high spatial frequencies were removed from the intact faces, or scrambled (isolating component processing), in which the locations of all face components were rearranged. Participants performed better on the memory test for own-race faces in both the blurred (configural) and scrambled (component) conditions, showing an own-race advantage for both configural and component processing. These results suggest that the own-race advantage in face recognition is due to a general facilitation in different forms of face processing.     

Global and local processing in adult humans (Homo sapiens), 5-year-old children (Homo sapiens), and adult cotton-top tamarins (Saguinus oedipus)

This study compared adults (Homo sapiens), young children (Homo sapiens), and adult tamarins (Saguinus oedipus) while they discriminated global and local properties of stimuli. Subjects were trained to discriminate a circle made of circle elements from a square made of square elements and were tested with circles made of squares and squares made of circles. Adult humans showed a global bias in testing that was unaffected by the density of the elements in the stimuli. Children showed a global bias with dense displays but discriminated by both local and global properties with sparse displays. Adult tamarins' biases matched those of the children. The striking similarity between the perceptual processing of adult monkeys and humans diagnosed with autism and the difference between this and normatively developing human perception is discussed.     

The development of facial emotion recognition: the role of configural information

The development of children's ability to recognize facial emotions and the role of configural information in this development were investigated. In the study, 100 5-, 7-, 9-, and 11-year-olds and 26 adults needed to recognize the emotion displayed by upright and upside-down faces. The same participants needed to recognize the emotion displayed by the top half of an upright or upside-down face that was or was not aligned with a bottom half that displayed another emotion. The results showed that the ability to recognize facial emotion develops with age, with a developmental course that depends on the emotion to be recognized. Moreover, children at all ages and adults exhibited both an inversion effect and a composite effect, suggesting that children rely on configural information to recognize facial emotions.     

Response inhibition and adaptations to response conflict in 6- to 8-year-old children: Evidence from the Simon effect

Several studies have shown that the Simon effect, which is the advantage of spatial correspondence between stimulus and response locations when the stimulus location is task-irrelevant, decreases with increasing response times and is affected by preceding-trial correspondence. These modulations suggest the existence of control mechanisms that adapt our behavior to current goals by responding to the conflict experienced within a trial and by preventing the recurrence of a conflict in the subsequent trial. The aim of the present study was to assess whether these control mechanisms, which are well consolidated in adults and in children older than 8 years of age, are present in children between 6 and 8 years old. To this end, we tested 32 first-grade (6–7 years) and 34 second-grade (7–8 years) children on a Simon task in which correspondence sequence was manipulated on a trial-by-trial basis. The Simon effect was larger for first- than for second-graders and decreased with increasing response times only in second-graders. Crucially, for both groups, the effect was reduced when the preceding trial was noncorresponding, and the reductions were comparable for the two groups, indicating that trial-by-trial control mechanisms are already present in first-grade children and may be dissociated from within-trial control adjustments.     

The respective role of low and high spatial frequencies in supporting configural and featural processing of faces

One distinctive feature of processing faces, as compared to other categories, is thought to be the large dependence on configural cues such as the metric relations among features. To test the role of low spatial frequencies (LSFs) and high spatial frequencies (HSFs) in configural and featural processing, subjects were presented with triplets of faces that were filtered to preserve either LSFs (below 8 cycles per face width), HSFs (above 32 cycles per face width), or the full frequency spectrum. They were asked to match one of two probe faces to a target face. The distractor probe face differed from the target either configurally, featurally, or both featurally and configurally. When the difference was at the configural level, performance was better with LSF faces than with HSF faces. In contrast, with a featural difference, a strong performance advantage was found for HSF faces as compared to LSF faces. These results support the dominant role that LSFs play in the configural processing of faces, whereas featural processing is largely dependent on HSFs.     

A configural dominant account of contextual cueing: Configural cues are stronger than colour cues

Previous work has shown that reaction times to find a target in displays that have been repeated are faster than those for displays that have never been seen before. This learning effect, termed “contextual cueing” (CC), has been shown using contexts such as the configuration of the distractors in the display and the background colour. However, it is not clear how these two contexts interact to facilitate search. We investigated this here by comparing the strengths of these two cues when they appeared together. In Experiment 1, participants searched for a target that was cued by both colour and distractor configural cues, compared with when the target was only predicted by configural information. The results showed that the addition of a colour cue did not increase contextual cueing. In Experiment 2, participants searched for a target that was cued by both colour and distractor configuration compared with when the target was only cued by colour. The results showed that adding a predictive configural cue led to a stronger CC benefit. Experiments 3 and 4 tested the disruptive effects of removing either a learned colour cue or a learned configural cue and whether there was cue competition when colour and configural cues were presented together. Removing the configural cue was more disruptive to CC than removing colour, and configural learning was shown to overshadow the learning of colour cues. The data support a configural dominant account of CC, where configural cues act as the stronger cue in comparison to colour when they are presented together.     

Converging evidence of configural processing of faces in high-functioning adults with autism spectrum disorders

There is conflicting evidence about whether individuals with autism spectrum disorder (ASD) demonstrate configural processing of faces. We examined two types of configural processing of unfamiliar faces in high-functioning adults with ASD: Holistic processing (processing a face as a gestalt percept) and processing of second-order relations (the spatial relations among facial features, e.g., distance between two eyes). Compared to age- and IQ-matched typical adults, 17 adults with ASD demonstrated normal holistic processing (as demonstrated by the composite face effect), normal sensitivity to second-order relations in upright faces, and the expected disruption of sensitivity to second-order relations in inverted faces. They were also normal in using the internal features and shape of the external contour to make same/different judgements about facial identity. The results provide converging evidence of configural processing of unfamiliar faces in high-functioning adults with ASD, and bring into question the generalizability of previous reports of abnormal face processing in individuals with ASD.     

Distinctiveness and expertise effects with homogeneous stimuli: towards a model of configural coding

Recent studies using Brennan's computerized caricature generator have demonstrated distinctiveness effects consistent with the idea that faces are coded in terms of their individual distinctive properties. Based on these findings it is suggested that, for homogeneous classes whose members share a common configuration, distinctive configural information may be coded as metric deviations from a spatial norm. Experiments are described which demonstrate similar distinctiveness effects in bird identification. Transformations that increase distinctiveness (caricatures) produced faster identification and a higher recognition proportion, for both experts and nonexperts, than transformations that reduce distinctiveness (anticaricatures). This distinctiveness advantage is consistent with the norm-based coding idea. Furthermore, within certain limits, increasing distinctiveness did not impair performance relative to that for veridical drawings. For experts there was also a caricature advantage, such that 50% caricatures of birds in a highly homogeneous and familiar class (passerines) were identified more quickly, provided that they were recognized at all, than uncaricatured veridical drawings. The significance of a caricature advantage for the visual coding of configural information is discussed.     

Development of sex differences in spatial memory.

Males typically perform better than females on tests of spatial abilities. However, Silverman and Eals (1992) found that females can surpass males on certain tasks, in particular recall of object location. This study investigated the age at which females begin having greater recall in object location. Recall was tested with object arrays (sets of line drawings of common objects) using samples of 80 adults (M age = 21 yr.) and 139 children at 3 age groups. Adult data replicated earlier findings, indicating significantly greater recall by women. The samples of children at different ages--4 yr. (n = 43), 10-11 yr. (n = 53), and 15-16 yr. (n = 43)--did not show significant sex differences in this type of recall. The findings suggest that females may surpass males in this spatial ability as adults, apparently due to gradual improvements in spatial memory through childhood and adolescence.     

Early sex differences in spatial skill.

This study investigated sex differences in young children's spatial skill. The authors developed a spatial transformation task, which showed a substantial male advantage by age 4 years 6 months. The size of this advantage was no more robust for rotation items than for translation items. This finding contrasts with studies of older children and adults, which report that sex differences are largest on mental rotation tasks. Comparable performance of boys and girls on a vocabulary task indicated that the male advantage on the spatial task was not attributable to an overall intellectual advantage of boys in the sample.     

Thatcher's children: development and the Thatcher illusion

Children do not show the same recognition disadvantage for inverted faces as adults do. It has been suggested that this is because the configural encoding (which is disrupted by inversion) becomes more useful or available as we get older. The distinction between configural processing and featural processing, however, is not always clear--it may be a dichotomy or a continuum. The perceived normal-to-grotesque switch in the Thatcher illusion was investigated, as the image was rotated, by people aged between 6 and 75 years. No effect of age was found, with young children showing the same effects as adults--the switch occurring at about 72 degrees. The development of face processing and the nature of facial configural encoding are discussed in the light of this result.     

What is learned in spatial contextual cuing--configuration or individual locations?

With the use of spatial contextual cuing, we tested whether subjects learned to associate target locations with overall configurations of distractors or with individual locations of distractors. In Experiment 1, subjects were trained on 36 visual search displays that contained 36 sets of distractor locations and 18 target locations. Each target location was paired with two sets of distractor locations on separate trials. After training, the subjects showed perfect transfer to recombined displays, which were created by combining half of one trained distractor set with half of another trained distractor set. This result suggests that individual distractor locations were sufficient to cue the target location. In Experiment 2, the subjects showed good transfer from trained displays to rescaled, displaced, and perceptually regrouped displays, suggesting that the relative locations among items were also learned. Thus, both individual target-distractor associations and configural associations are learned in contextual cuing.