Perceptual Grouping and Distance Estimates in Typical and Atypical Development: Comparing Performance across Perception, Drawing and Construction Tasks

Perceptual grouping is a pre-attentive process which serves to group local elements into global wholes, based on shared properties. One effect of perceptual grouping is to distort the ability to estimate the distance between two elements. In this study, biases in distance estimates, caused by four types of perceptual grouping, were measured across three tasks, a perception, a drawing and a construction task in both typical development (TD; Experiment 1) and in individuals with Williams syndrome (WS; Experiment 2). In Experiment 1, perceptual grouping distorted distance estimates across all three tasks. Interestingly, the effect of grouping by luminance was in the opposite direction to the effects of the remaining grouping types. We relate this to differences in the ability to inhibit perceptual grouping effects on distance estimates. Additive distorting influences were also observed in the drawing and the construction task, which are explained in terms of the points of reference employed in each task. Experiment 2 demonstrated that the above distortion effects are also observed in WS. Given the known deficit in the ability to use perceptual grouping in WS, this suggests a dissociation between the pre-attentive influence of and the attentive deployment of perceptual grouping in WS. The typical distortion in relation to drawing and construction points towards the presence of some typical location coding strategies in WS. The performance of the WS group differed from the TD participants on two counts. First, the pattern of overall distance estimates (averaged across interior and exterior distances) across the four perceptual grouping types, differed between groups. Second, the distorting influence of perceptual grouping was strongest for grouping by shape similarity in WS, which contrasts to a strength in grouping by proximity observed in the TD participants

Understanding strategic information use during emotional expression judgments in Williams syndrome

Detailed analysis of expression judgments in Williams syndrome reveals that successful emotion categorization need not reflect ‘classic’ information processing strategies. These individuals draw upon a distinct set of featural details to identify happy and fearful faces that differ from those used by typically developing comparison groups: children and adults. The diagnostic visual information is also notably less interlinked in Williams syndrome, consistent with reports of diminished processing of configural information during face identity judgments. These results prompt reconsideration of typical models of face expertise by revealing that an age-appropriate profile of expression performance can be achieved via alternative routes

Distinct profiles of information-use characterize identity judgments in children and low-expertise adults

Face processing abilities vary across the lifespan: increasing across childhood and adolescence, peaking around 30 years of age, and then declining. Despite extensive investigation, researchers have yet to identify qualitative changes in face processing during development that can account for the observed improvements on laboratory tests. The current study constituted the first detailed characterization of face processing strategies in a large group of typically developing children and adults (N=200) using a novel adaptation of the Bubbles reverse correlation technique (Gosselin & Schyns, 2001). Resultant classification images reveal a compelling age-related shift in strategic information-use during participants’ judgments of face identity. This shift suggests a move from an early reliance upon high spatial frequency details around the mouth, eye-brow and jaw-line in young children (~8yrs) to an increasingly more interlinked approach, focused upon the eye region and the center of the face in older children (~11yrs) and adults. Moreover, we reveal that the early vs. late phases of this developmental trajectory correspond with the profiles of information-use observed in weak vs. strong adult face processors. Together, these results provide intriguing new evidence for an important functional role for strategic information-use in the development of face expertise

Evidence for unusual spatial location coding in Williams syndrome: An explanation for the local bias in visuo-spatial construction tasks?

Individuals with Williams syndrome (WS) display poor visuo-spatial cognition relative to verbal abilities. Furthermore, whilst perceptual abilities are delayed, visuo-spatial construction abilities are comparatively even weaker, and are characterised by a local bias. We investigated whether this differentiation in visuo-spatial abilities can be explained by a deficit in coding spatial location in WS. This can be measured by assessing participants? understanding of the spatial relations between objects within a visual scene. Coordinate and categorical spatial relations were investigated independently in four participant groups: 21 individuals with WS; 21 typically developing (TD) children matched for non-verbal ability; 20 typically developing controls of a lower non-verbal ability; and 21 adults. A third task measured understanding of visual colour relations. Results indicated first, that the comprehension of categorical and co-ordinate spatial relations is equally poor in WS. Second, that the comprehension of visual relations is also at an equivalent level to spatial relational understanding in this population. These results can explain the difference in performance on visuo-spatial perception and construction tasks in WS. In addition, both the WS and control groups displayed response biases in the spatial tasks. However, the direction of bias differed across the groups. This finding is explored in relation to current theories of spatial location coding

Block design performance in Williams syndrome : visuospatial abilities or task approach skills?

The block design task (BDT) is a visuospatial measure that individuals with Williams syndrome (WS) perform poorly on. However, it is unclear what underlies their impaired performance. This study investigated whether poorer performance is a result of visuospatial difficulties, executive function (EF) difficulties, atypical looking strategies, or a combination of these. Eleven individuals with WS participated alongside mental age (MA)- and chronological age (CA)-matched control groups. Eye movements were recorded while they took the BDT. Dwell times and visits to areas of interest in WS differed from CA, but not MA, groups. Findings suggest that BDT abilities of individuals with WS are delayed, but not atypical. Delays result from visuospatial and attention-switching difficulties rather than atypical looking strategies

Perceptual grouping ability in Williams syndrome: Evidence for deviant patterns of performance

Williams syndrome (WS) is a rare genetic disorder. At a cognitive level, this population display poor visuo-spatial cognition when compared to verbal ability. Within the visuo-spatial domain, it is now accepted that individuals with WS are able to perceive both local and global aspects of an image, albeit at a low level. The present study examines the manner in which local elements are grouped into a global whole in WS. Fifteen individuals with WS and 15 typically developing controls, matched for non-verbal ability, were presented with a matrix of local elements and asked whether these elements were perceptually grouped horizontally or vertically. The WS group were at the same level as the control group when grouping by luminance, closure, and alignment. However, their ability to group by shape, orientation and proximity was significantly poorer than controls. This unusual profile of grouping abilities in WS suggests that these individuals do not form a global percept in a typical manner

Cross-Domain Associations Between Motor Ability, Independent Exploration, and Large-Scale Spatial Navigation; Attention Deficit Hyperactivity Disorder, Williams Syndrome, and Typical Development.

In typical infants, the achievement of independent locomotion has a positive impact on the development of both small-scale and large-scale spatial cognition. Here we investigated whether this association between the motor and spatial domain: (1) persists into childhood and (2) is detrimental to the development of spatial cognition in individuals with motor deficits, namely, individuals with attention deficit hyperactivity disorder (ADHD) and individuals with Williams syndrome (WS). Despite evidence of a co-occurring motor impairment in many individuals with ADHD, little is known about the developmental consequences of this impairment. Individuals with WS demonstrate impaired motor and spatial competence, yet the relationship between these two impairments is unknown. Typically developing (TD) children (N = 71), individuals with ADHD (N = 51), and individuals with WS (N = 20) completed a battery of motor tasks, a measure of independent exploration, and a virtual reality spatial navigation task. Retrospective motor milestone data were collected for the ADHD and WS groups. Results demonstrated a relationship between fine motor ability and spatial navigation in the TD group, which could reflect the developmental impact of the ability to manually manipulate objects, on spatial knowledge. In contrast, no relationships between the motor and spatial domains were observed for the ADHD or WS groups. Indeed, while there was evidence of motor impairment in both groups, only the WS group demonstrated an impairment in large-scale spatial navigation. The motor-spatial relationship in the TD, but not the ADHD and WS groups, suggests that aspects of spatial cognition can develop via a developmental pathway which bypasses input from the motor domain

Using virtual environments to investigate wayfinding in 8- to 12-year-olds and adults

Wayfinding is the ability to learn and recall a route through an environment. Theories of wayfinding suggest that for children to learn a route successfully, they must have repeated experience of it, but in this experiment we investigated whether children could learn a route after only a single experience of the route. A total of 80 participants from the United Kingdom in four groups of 20 8-year-olds, 10-year-olds, 12-year-olds, and adults were shown a route through a 12-turn maze in a virtual environment. At each junction, there was a unique object that could be used as a landmark. Participants were ‘‘walked” along the route just once (without any verbal prompts) and then were asked to retrace the route from the start without any help. Nearly three quarters of the 12-year-olds, half of the 10-year-olds, and a third of the 8-year-olds retraced the route without any errors the first time they traveled it on their own. This finding suggests that many young children can learn routes, even with as many as 12 turns, very quickly and without the need for repeated experience. The implications for theories of wayfinding that emphasize the need for extensive experience are discussed

Spatial Thinking in Practice: A Snapshot of teacher’s Spatial Activity Use in the Early Years’ Classroom

Spatial thinking predicts Science, Technology, Engineering, and Mathematics achievement, yet is often absent from educational policy. We provide benchmarks of teachers' usage and perceptions of spatial activities in practice in the reception classroom (first year of primary school). In this questionnaire study of educational professionals working in the reception classroom in England (N = 104), we found that spatial and numeracy activities were perceived as significantly less important, and were reportedly completed significantly less often, than literacy or life skills. Despite the lower perceived importance of spatial skills in curriculum guidance in England, rates of reported spatial activity use were encouragingly high and were broadly comparable to those of numeracy. Teachers had moderate anxiety levels for both spatial and mathematics domains. The findings highlight a need to elevate teachers' understanding of the importance of developing children's early spatial and numeracy skills, which may begin with efforts to reduce spatial and mathematics anxiety

Cross-sectional and longitudinal assessment of cognitive development in Williams syndrome

Williams syndrome (WS) is a rare genetic syndrome. As with all rare syndromes, obtaining adequately powered sample sizes is a challenge. Here we present legacy data from seven UK labs, enabling the characterisation of cross-sectional and longitudinal developmental trajectories of verbal and non-verbal development in the largest sample of individuals with WS to-date. In Study 1, we report cross-sectional data between N = 102 and N = 209 children and adults with WS on measures of verbal and non-verbal ability. In Study 2, we report longitudinal data from N = 17 to N = 54 children and adults with WS who had been tested on at least three timepoints on these measures. Data support the WS characteristic cognitive profile of stronger verbal than non-verbal ability, and shallow developmental progression for both domains. Both cross-sectional and longitudinal data demonstrate steeper rates of development in the child participants than the adolescent and adults in our sample. Cross-sectional data indicate steeper development in verbal than non-verbal ability, and that individual differences in the discrepancy between verbal and non-verbal ability are largely accounted for by level of intellectual functioning. A diverging developmental discrepancy between verbal and non-verbal ability, whilst marginal, is not mirrored statistically in the longitudinal data. Cross-sectional and longitudinal data are discussed with reference to validating cross-sectional developmental patterns using longitudinal data and the importance of individual differences in understanding developmental progression