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Background: Individuals with Down syndrome (DS) appear to perform at a level that is commensurate with developmental expectations on simple tasks of selective attention. In this study, we examine how their selective attention is impacted by target changes that unfold over both time and space. This increased complexity reflects an attempt at greater ecological validity in an experimental task, as a steppingstone for better understanding attention among persons with DS in real-world environments., Methods: A modified flanker task was used to assess visual temporal and spatial filtering among persons with DS (n = 14) and typically developing individuals (n = 14) matched on non-verbal mental age (mental age = 8.5 years). Experimental conditions included varying the stimulus onset asynchronies between the onset of the target and flankers, the distances between the target and flankers, and the similarity of the target and flankers., Results: Both the participants with DS and the typically developing participants showed slower reaction times and lower accuracy rates when the flankers appeared closer in time and/or space to the target., Conclusion: No group differences were found on a broad level, but the findings suggest that dynamic stimuli may be processed differently by those with DS. Implications of the findings are discussed in relation to the developmental approach to intellectual disability originally articulated by Ed Zigler., (© 2022 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.)

The findings are evidence that persons with ASD benefit more than typically developing (TD) persons from spatial framing cues in focusing their attention on a visual target. Participants were administered a forced-choice task to assess visual filtering. A target stimulus was presented on a screen and flanker stimuli were presented simultaneously with or after the target, with varying stimuli onset asynchronies (SOAs). Regardless of SOA, TD children showed the expected distracting effects with slower reaction times (RTs) when flankers were at closer distances from the target. However, children with ASD displayed shorter RTs in the conditions in which the stimuli were presented simultaneously or with a short SOA. These findings are interpreted as reflecting utilitarian attention among children with ASD.

Endogenous visual orienting among children with autism spectrum disorders (ASDs) and among typically developing (TD) children was examined using a Posner-type task that was modified to include social and nonsocial cues and targets to test hypotheses regarding information (social or nonsocial) and cue processing (long or short stimulus onset asynchronies (SOAs)). The findings suggest intact endogenous orienting to face and mixed face targets using hand and arrow cues among children with ASDs who were matched to typically developing children (TDC) on the basis of nonverbal mental age (MA) at approximately 8.5 years. The findings from this study challenge the notions of a social orienting impairment and of mechanical social orienting as the children with ASDs in this study demonstrated strong orienting effects in all conditions and social sensitivity in the long stimulus onset asynchrony (SOA) condition., (© 2015 International Society for Autism Research, Wiley Periodicals, Inc.)

Time estimation of short durations (under 1 sec) was examined in low-functioning individuals with autism spectrum disorder (ASD) and typically developing (TD) children matched on mental age. Temporal bisection and generalization tasks were used to examine basic perceptual timing mechanisms. For both tasks, the participants with ASD demonstrated less sensitivity to variability in short durations than the TD children, adding to a growing body of literature suggesting deficits in timing exist for longer durations. The results highlight the need to examine multiple levels of processing of time-related information from basic perceptual mechanisms to higher level cognitive mechanisms., (© 2014 International Society for Autism Research, Wiley Periodicals, Inc.)

We investigated differences in multiple-object tracking among individuals with Down syndrome (DS) as compared to typically developing children matched on a visual-spatial mental age of approximately 5.5 years. In order to ensure that these effects did not originate in differences in encoding or reporting the positions of targets in distracters after a delay, immediate and delayed report were measured for static items. Although their immediate and delayed report for multiple static items was comparable to that of the typically developing children, the participants with DS performed as if they were only capable of tracking a single item at a time regardless of the number of targets that needed to be tracked. This finding is surprising because the operations used in multiple-object tracking are thought to be necessary for visuospatial tasks, which are an area of relative strength among persons with DS. These results call into question the idea that abilities or deficits in multiple-object tracking predict visuospatial performance, and highlight ways that atypical development can inform our understanding of typical development.

Objective: Investigated the relationship between selective and sustained attention and social behavior in children with different degrees of attentional disturbance., Method: Participants were 101 6- to 12-year-old children, including 18 who were diagnosed with Attention Deficit Hyperactivity Disorder (AD/HD), 61 who were clinically referred for attentional difficulties but did not meet criteria for ADHD, and 22 typically developing children. Two groups of children completed either a sustained attention task or a selective attention task. Task performance was compared with teacher reported social behavior., Results: In support of the investigator's hypothesis poor performance on the sustained attention task correlated with social behavior problems. However, contrary to expectation, poor performance on the selective attention task was not correlated with teacher reported social problems. Results are discussed with specific emphasis on the need to identify underlying cognitive contributions to social dysfunction., Conclusion: The findings support a growing body of research highlighting the negative relationship between inattention and social functioning.

The influence of age on a selective attention task was studied in a sample of children with and without Attention Deficit Hyperactivity Disorder (ADHD). The impact of methylphenidate (MPH) treatment on selective attention was also investigated in the children with ADHD. Two age groups of children with ADHD and two age groups of control children were tested using a timed computer task. The task consisted of identifying visual target stimuli under various distracter conditions. Distracters varied on the basis of modality (i.e., visual, auditory, or both) and task relevance (i.e., meaningful or irrelevant). Reaction times and accuracy were measured. Children with ADHD were less efficient on the selective attention task than were children without ADHD, and older children were more efficient than younger children in both groups. Children without ADHD were influenced more by the nature of distracters than were children with ADHD. For children with ADHD, MPH improved performance overall.

This study investigated whether a group of children with reading disabilities (RD) were slower at processing visual information in general (compared to a group of children of comparable age and a group of children of comparable reading level), or whether their deficit was specific to the written word. Computerized backward masking and temporal integration tasks were used to assess the speed of visual information processing. Stimulus complexity (simple, complex) and type (verbal, nonverbal) were varied, creating a 2 x 2 matrix of stimulus conditions: simple nonverbal, complex nonverbal, simple verbal, and complex verbal. Adolescents with RD demonstrated difficulties in processing rapidly presented verbal and nonverbal visual stimuli, although the effect was magnified when they were processing verbal stimuli. Thus, the results of this study suggest that some youth with reading disabilities have visual temporal processing deficits that compound difficulties in processing verbal information during reading.

Covert visual orienting was examined over a span of human life ranging from six to 73 years. The observer's task was the speeded discrimination of "X" from "O1" but of primary interest was the effect of a location cue that appeared prior to the target. Both an abrupt stimulus cue and a voluntary information cue were studied using response time (RT) measures. Eye movements were monitored to control for differences in the ability to maintain fixation. Experiment 1 showed that there were very few age differences in stimulus-cued orienting. In contrast, there were important differences when orienting was intentional. In comparison with young adults, children were less able to sustain orienting over time, and senior adults required more time to use the cue. Experiment 2 tested the relation between stimulus and information cues when they both occurred prior to a given target. All age groups were able to use information cues in the presence of conflicting stimulus cues, but young adults were better able to do so than either children or senior adults. These results are interpreted as support for the view that separate mechanisms underlie stimulus-based versus information-based spatial orienting.

Observers aged 6, 8, and 20 years participated in a speeded classification task designed to measure covert shifts of visual attention. On each trial observers responded to a target which appeared in one of three locations arrayed horizontally across the display. Three prestimulus cues were employed: neutral (the cue was present in all three possible target locations), unpredictable (the cue was present in the target location on a random basis), and predictable (the cue was present in the target location on 80% of the trials). There were four developmental findings: (1) Observers of all ages oriented attention automatically to the cued locations, (2) children processed targets in non-cued locations more slowly than adults, (3) only adults took advantage of the predictability of the cue, and (4) all age groups provided evidence that strategic orienting competes with response priming for cognitive resources. The implications of these findings for theories of attentional development are discussed.