Giles M. Anderson

Visual preference for social stimuli in individuals with autism or neurodevelopmental disorders: an eye-tracking study

BackgroundRecent research has identified differences in relative attention to competing social versus non-social video stimuli in individuals with autism spectrum disorder (ASD). Whether attentional allocation is influenced by the potential threat of stimuli has yet to be investigated. This is manipulated in the current study by the extent to which the stimuli are moving towards or moving past the viewer. Furthermore, little is known about whether such differences exist across other neurodevelopmental disorders. This study aims to determine if adolescents with ASD demonstrate differences in attentional allocation to competing pairs of social and non-social video stimuli, where the actor or object either moves towards or moves past the viewer, in comparison to individuals without ASD, and to determine if individuals with three genetic syndromes associated with differing social phenotypes demonstrate differences in attentional allocation to the same stimuli.MethodsIn study 1, adolescents with ASD and control participants were presented with social and non-social video stimuli in two formats (moving towards or moving past the viewer) whilst their eye movements were recorded. This paradigm was then employed with groups of individuals with fragile X, Cornelia de Lange, and Rubinstein-Taybi syndromes who were matched with one another on chronological age, global adaptive behaviour, and verbal adaptive behaviour (study 2).ResultsAdolescents with ASD demonstrated reduced looking-time to social versus non-social videos only when stimuli were moving towards them. Individuals in the three genetic syndrome groups showed similar looking-time but differences in fixation latency for social stimuli moving towards them. Across both studies, we observed within- and between-group differences in attention to social stimuli that were moving towards versus moving past the viewer.ConclusionsTaken together, these results provide strong evidence to suggest differential visual attention to competing social versus non-social video stimuli in populations with clinically relevant, genetically mediated differences in socio-behavioural phenotypes.

Implicit Discrimination of Basic Facial Expressions of Positive/Negative Emotion in Fragile X Syndrome and Autism Spectrum Disorder

Fragile X syndrome (FXS) and autism spectrum disorders (ASD) are characterized by impaired social functioning. We examined the spontaneous discrimination of happy and disgusted facial expressions, from neutral faces, in individuals with FXS (n  =  13, Mage  =  19.70) and ASD (n  =  15, Mage  =  11.00) matched on adaptive behavior and verbal abilities measured by the Vineland Adaptive Behavior Scale. Eye gaze to the eyes and mouth of neutral faces was also measured. Results suggest individuals with FXS and ASD distinguish facial expressions spontaneously in the same way. Individuals with FXS looked significantly less at the eye region of neutral faces than individuals with ASD. These results provide insight into similarities and differences in face processing in two neurodevelopmental disorders noted for their similarities in social behavior.

Hide and seek: The theory of mind of visual concealment and search

Researchers have investigated visual search behavior for almost a century. During that time, few studies have examined the cognitive processes involved in hiding items rather than finding them. To investigate this, we developed a paradigm that allowed participants to indicate where they would hide (or find) an item that was to be found (or hidden) by a friend or a foe. We found that (i) for friends more than foes, participants selected the pop-out item in the display, and (ii) when the display was homogeneous, they selected nearby and corner items. These behaviors held for both hiding and finding, although hide and find behaviors were not identical. For pop-out displays, decision times were unusually long when hiding an item from a foe. These data converge on the conclusion that the principles of search and concealment are similar, but not the same. They also suggest that this paradigm will provide researchers a powerful method for investigating theory of mind in adults.

Top-down guidance of eye movements in conjunction search.

We provide novel evidence for a two-stage model of visual search applied to the selection based on top-down cues to stimulus colour and orientation. The model supposes that visual displays are first parsed into colour based groups, a process that is modulated by the presence of an initial cue to the targets colour. Subsequently search is directed to other featural properties represented within the colour-based groups. Cues to the orientation of the target are only effective at this second stage. The results provide strong evidence that colour and orientation cues operate in different ways to guide search.

Differential time course of implicit and explicit cueing by colour and orientation in visual search

Using a cued conjunction search task, Anderson, Heinke, and Humphreys (2010) demonstrated larger effects from cueing target colour than from cueing target orientation. In this study, we separated the implicit (nonexpectation-dependent) and explicit (expectation-dependent) effects of orientation and colour visual cues. In Experiment 1, we replicated the original findings for short cue durations (100–200 ms), demonstrating that cues matching the physical property of the target on 80% of trials exert a rapid effect on search. These early cueing effects on reaction times were supported by evidence of guidance from cues on early eye movements. Experiment 2 introduced a feature to the cue that randomly matched the colour or orientation of the target. When cue orientation was predictive, there were strong implicit effects based on whether the colour of the cue and target matched. When cue colour was predictive, there were only weak effects from the cues orientation. Implicit effects from cue colour remained when orientation-predictive cues were used and colour was unlikely to predict the target (Experiment 3). The data suggest that strong effects of colour cueing result from a combination of implicit and explicit processes, whereas effects from orientation cues are largely limited to the explicit guidance of visual search.

Face scanning and spontaneous emotion preference in Cornelia de Lange syndrome and Rubinstein-Taybi syndrome

BackgroundExisting literature suggests differences in face scanning in individuals with different socio-behavioural characteristics. Cornelia de Lange syndrome (CdLS) and Rubinstein-Taybi syndrome (RTS) are two genetically defined neurodevelopmental disorders with unique profiles of social behaviour.MethodsHere, we examine eye gaze to the eye and mouth regions of neutrally expressive faces, as well as the spontaneous visual preference for happy and disgusted facial expressions compared to neutral faces, in individuals with CdLS versus RTS.ResultsResults indicate that the amount of time spent looking at the eye and mouth regions of faces was similar in 15 individuals with CdLS and 17 individuals with RTS. Both participant groups also showed a similar pattern of spontaneous visual preference for emotions.ConclusionsThese results provide insight into two rare, genetically defined neurodevelopmental disorders that have been reported to exhibit contrasting socio-behavioural characteristics and suggest that differences in social behaviour may not be sufficient to predict attention to the eye region of faces. These results also suggest that differences in the social behaviours of these two groups may be cognitively mediated rather than subcortically mediated.

Bottom-up guidance to grouped items in conjunction search: Evidence for color grouping

Previous studies have demonstrated that observers can search through a subset of items carrying a minority feature to find a conjunction target (Sobel & Cave, 2002). We examined whether subset search takes place when participants have less specific foreknowledge of the target (when the target is one of two possible items), measuring eye movements as well as reaction times. When there were unequal ratios of distractors, fixations were initially directed to the small subset. These initial eye movements were often directed between items with the same feature, suggesting guidance from pooled feature values. There was stronger guidance within color- than orientation-defined groups, although the features were balanced for salience. The results suggest that grouping of items by color operates more globally than grouping in orientation.

People or trains? Visual preference for social versus non-social information in genetic syndromes.

Aim: Our goal was to test the efficacy of an adapted health promotionintervention entitled ‘HealthMatters Program’ (originally developed by Marks etal., 2013) on health related outcomes for people with intellectual disabilities (ID),and on staffs’ knowledge and attitudes in supporting this population to adopt ahealthy lifestyle. This study also explored facilitators and barriers to engagementin health promotion activities. Method: A multiphase mixed methods approachwas used. A pre-post single design tested the outcomes of the programme on 28staff (attitudes and nutrition knowledge) and 46 individuals with ID (weight,nutrition knowledge, health behaviour, nutrition self-efficacy and socialsupports). These outcomes were assessed pre-intervention, and 3 and 6 monthspost-intervention. Following this the barriers and facilitators to implementing theprogramme were explored within focus groups. Results: Nutritional knowledgeoutcomes improved significantly for staff and people with ID. The focus groupsfound that consistent commitment from staff, managers and individuals with IDwas critical to ensuring successful application of knowledge acquired from theprogramme in order to positively change health knowledge and behaviours.Conclusion: Organisational, staff and service user buy in influenced successfulimplementation of the adapted ‘HealthMatters Program’ and adherence tohealthy lifestyles.