111 research outputs found
Glucose modulates event-related potential components of recollection and familiarity in healthy adolescents.
No full textIntroduction Behavioural evidence supports the notion that oral glucose ingestion enhances recognition memory judgements based on recollection, but not familiarity. The present study sought to clarify and extend upon these behavioural findings by investigating the influence of glucose administration on event-related potential (ERP) components that are thought to be differentially mediated by recollection and familiarity processes in healthy adolescents. Methods In a within-subjects design, participants performed a recognition memory task, during which time electroencephalogram (EEG) was recorded, subsequent to ingestion of either (a) glucose or (b) placebo in a counterbalanced order. Results Response times during the recognition memory task were observed to be faster for the glucose condition, relative to a placebo control. Further, glucose ingestion was associated with an enhanced left parietal old/new ERP effect (a marker of recollection) and an enhanced mid-frontal old/new ERP effect (known to be mediated by familiarity). Discussion These findings (a) support the results of previous research that the ‘glucose memory facilitation effect’ can be extended to healthy adolescents, but (b) suggest that glucose enhances both the recollection and familiarity components of recognition memory. The observed ERP profile has important implications for the proposal that glucose specifically targets the hippocampus in modulating cognitive performance
Spontaneous and cued gaze-following in autism and Williams syndrome
No full textBackground: From a young age the typical development of social functioning relies upon the allocation of attention to socially relevant information, which in turn allows experience at processing such information and thus enhances social cognition. As such, research has attempted to identify the developmental processes that are derailed in some neuro-developmental disorders that impact upon social functioning. Williams syndrome (WS) and Autism are disorders of development that are characterized by atypical yet divergent social phenotypes and atypicalities of attention to people. Methods: We used eye tracking to explore how individuals with WS and Autism attended to, and subsequently interpreted, an actor’s eye gaze cue within a social scene. Images were presented for three seconds, initially with an instruction simply to look at the picture. The images were then shown again, with the participant asked to identify the object being looked at. Allocation of eye-gaze in each condition was analyzed by ANOVA and accuracy of identification was compared with t-tests. Results: Participants with WS allocated more gaze time to face and eyes than their matched controls both with and without being asked to identify the item being looked at; while participants with Autism spent less time on face and eyes in both conditions. When cued to follow gaze, participants with WS increased gaze to the correct targets, while those with Autism looked more at the face and eyes but did not increase gaze to the correct targets, while continuing to look much more than their controls at implausible targets. Both groups identified fewer objects than their controls. Conclusions: The atypicalities found are likely to be entwined with the deficits shown in interpreting social cognitive cues from the images. WS and Autism are characterised by atypicalities of social attention that impact upon socio-cognitive expertise but importantly the type of atypicality is syndrome-specific
Exploring face perception in disorders of development: evidence from Williams syndrome and autism
No full textIndividuals with Williams syndrome (WS) and autism are characterized by different social phenotypes but have been said to show similar atypicalities of face-processing style. Although the structural encoding of faces may be similarly atypical in these two developmental disorders, there are clear differences in overall face skills. The inclusion of both populations in the same study can address how the profile of face skills varies across disorders. The current paper explored the processing of identity, eye-gaze, lip-reading, and expressions of emotion using the same participants across face domains. The tasks had previously been used to make claims of a modular structure to face perception in typical development. Participants with WS (N=15) and autism (N=20) could be dissociated from each other, and from individuals with general developmental delay, in the domains of eye-gaze and expression processing. Individuals with WS were stronger at these skills than individuals with autism. Even if the structural encoding of faces appears similarly atypical in these groups, the overall profile of face skills, as well as the underlying architecture of face perception, varies greatly. The research provides insights into typical and atypical models of face perception in WS and autism
Lifestyle, glucose regulation and the cognitive effects of glucose load in middle-aged adults
No full textInterventions aimed at improving glucose regulatory mechanisms have been suggested as a possible source of cognitive enhancement in the elderly. In particular, previous research has identified episodic memory as a target for facilitation after either moderate increases in glycaemia (after a glucose drink) or after improvements in glucose regulation. The present study aimed to extend this research by examining the joint effects of glucose ingestion and glucose regulation on cognition. In addition, risk factors associated with the development of poor glucose regulation in middle-aged adults were considered. In a repeated measures design, thirty-three middle-aged adults (aged 35–55 years) performed a battery of memory and non-memory tasks after either 25 g or 50 g glucose or a sweetness matched placebo drink. To assess the impact of individual differences in glucose regulation, blood glucose measurements were taken on four occasions during testing. A lifestyle and diet questionnaire was also administered. Consistent with previous research, episodic memory ability benefited from glucose ingestion when task demands were high. Blood glucose concentration was also found to predict performance across a number of cognitive domains. Interestingly, the risk factors associated with poor glucose regulation were linked to dietary impacts traditionally associated with poor health, e.g. the consumption of high-sugar sweets and drinks. The research replicates earlier work suggesting that task demands are critical to the glucose facilitation effect. Importantly, the data demonstrate clear associations between elevated glycaemia and relatively poor cognitive performance, which may be partly due to the effect of dietary and lifestyle factors
Gaze aversion as a cognitive load management strategy in autism spectrum disorder and Williams syndrome
No full textDuring face-to-face questioning typically developing children and adults use gaze aversion (GA), away from their questioner, when thinking. GA increases with question difficulty and improves the accuracy of responses. This is the first study to investigate whether individuals with autism spectrum disorder (ASD; associated with reduced sociability and atypical face gaze) and Williams syndrome (WS; associated with hypersociability and atypical face gaze) use GA to manage cognitive load during face-to-face interactions
Tracking eye movements proves informative for the study of gaze direction detection in autism
No full textConsiderable research effort has been dedicated to exploring how well children with autistic spectrum disorders infer eye gaze direction from the face of an actor. Here we combine task performance (accuracy to correctly label a target item) and eye movement information (‘where’ the participant fixates when completing the task) to understand more about the components involved in completing eye direction detection tasks. Fifteen participants with autism were significantly less accurate at interpreting eye direction and detecting a target item (array sizes 4 and 6 items) than typically developing participants of comparable nonverbal ability. Eye movement data revealed subtly different fixation patterns for participants with and without autism that might contribute to differences in overall task performance. Although the amount of time spent fixating on the target item did not differ across groups, participants with autism took significantly longer to complete several components of the task and fixate upon the regions of the picture required for task completion (e.g. face or target). The data have implications for the design of tasks for individuals with autism and provide insights into the usefulness of including measures of visual attention in understanding task performance
Exploring the forgetting mechanisms in working memory: Evidence from a reasoning span test
No full textThis is an electronic version of an article published in [Saito, S., C. Jarrold, and D. M. Riby. 2009. Exploring the forgetting mechanisms in working memory: Evidence from a reasoning span test. Quarterly Journal of Experimental Psychology 62, (7): 1401-1419.]. This Article is available online at: http://www.informaworld.com/smpp/content~db=all?content=10.1080/17470210802426924In working memory (WM) span tests participants have to maintain to-be-remembered information while processing other, potentially distracting, information. Previous studies have shown that WM span scores are greater when span lists start with a long processing task and end with a short processing task than when these processing tasks are presented in the reverse order (e.g., Towse, Hitch, Hutton, 2000). In Experiment 1, we obtained a similar stimulus order effect in a reasoning span test, using reasoning sentences that were equated for length in terms of the number of constituent words, but which differed in processing complexity; span scores were greater when lists began with a complex sentence and ended with a simple sentence than when this stimulus order was reversed. In Experiment 2, the stimulus order effect was not found when processing duration was held constant while sentence complexity was varied using a computer-paced moving window presentation paradigm. These results suggest that duration-based constraints can affect degree of forgetting independently of the load generated during processing phases in WM span performance and therefore imply that time-related forgetting can occur in WM span tests, particularly when the difficulty of the processing component blocks active maintenance of to-be-remembered material
Do faces capture the attention of individuals with Williams syndrome or Autism? Evidence from tracking eye movements
No full textThe neuro-developmental disorders of Williams syndrome (WS) and autism can reveal key components of social cognition. Eye‐tracking techniques were applied in two tasks exploring attention to pictures containing faces. Images were i) scrambled pictures containing faces or ii) pictures of scenes with embedded faces. Compared to individuals who were developing typically, participants with WS and autism showed atypicalities of gaze behaviour. Individuals with WS showed prolonged face gaze across tasks, relating to the typical WS social phenotype. Participants with autism exhibited reduced face gaze, linking to a lack of interest in socially relevant information. The findings are interpreted in terms of wider issues regarding socio‐cognition and attention mechanisms
Developmental trajectories of structural and pragmatic language skills in school-aged children with Williams syndrome
No full textThis study aimed to compare developmental courses of structural and pragmatic language skills in school-aged children with Williams syndrome (WS) and children with idiopathic intellectual disability (IID). Comparison of these language trajectories could highlight syndrome-specific developmental features.sponsorship: Marguerite-Marie Delacroixstatus: Publishe
Eye-tracking explorations of attention to faces for communicative cues in Autism Spectrum Disorders
No full textBackground
Individuals with Autism Spectrum Disorder (ASD) have been reported to show socio-communicative impairments which are associated with impaired face perception and atypical gaze behaviour. Attending to faces and interpreting the important socio-communicative cues presented allows us to understand other’s cognitive states, emotions, wants and desires. This information enables successful social encounters and interactions to take place. Children with ASD not attending to these important social cues on the face may cause some of the socio-communicative impairments observed within this population. Examining how children with ASD attend to faces will enhance our understanding of their communicative impairments.
Aim
The present thesis therefore aimed to use eye-tracking methodology to examine attention allocation to faces for communicative cues in children with ASD.
Method
The first line of enquiry examined how children with ASD (n = 21; age = 13y7m) attended to faces presented within their picture communication systems compared to typically developing children matched on chronological age, verbal ability age and visuo-spatial ability age. The next investigation was conducted on the same group of children and examined how children with ASD attended to faces of different familiarity including, familiar, unfamiliar and the child’s own face. These faces were also presented with direct gaze or averted gaze to investigate how this would impact on the children’s allocation of attention. The final exploration highlighted how children with ASD (n = 20; age = 12y3m) attended to socially salient information (faces) and non-socially salient information (objects) presented within social scenes of varying complexity, compared to typically developing controls. Again groups were matched based on chronological age, verbal ability age, and visuo-spatial ability age.
Results
Children with ASD were shown to allocate attention to faces presented within their picture communication symbols similarly compared to their typically developing counterparts. All children were shown to fixate significantly longer on the face images compared to the object images. The children with ASD fixated for similar amounts of time to the eye and mouth regions regardless of familiarity and gaze direction compared to their controlled matches. All groups looked significantly longer at the eye areas compared to the mouth areas of the faces across all familiarity types. The children also fixated longer on the eye and mouth regions of direct gazing faces compared to the regions presented on the averted gazing faces. The children with ASD fixated on the faces and objects presented within social scenes similar to their typically developing counterparts across all complexity conditions. The children were shown to fixate significantly longer on the objects compared to the faces.
Conclusions
Children with ASD showed typical allocation of attention to faces. This suggests that faces are not aversive to them and they are able to attend to the relevant areas such as eye and mouth regions. This may have been influenced by the inclusion of high functioning children with ASD. However these results may also suggest that attention allocation and gaze behaviour are not the only factors which contribute to the socio-communicative impairments observed in ASD
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