Measuring aspects of attention in persons with intellectual disability

2017-03-23T03:36:56Z (GMT) by Esther Sofia Ginsberg
Attention is a complex construct, inextricably related to other mental functions. Consequently, tasks that purportedly measure attention actually tend to examine a number of inter-related processes. This issue must be considered in the development of tests of attention. Adding to the challenge, tasks evaluating attention in persons with intellectual disabilities must be of low demand to avoid disengagement and feelings of inadequacy due to repeated performance failure.
   Five tasks were developed or adapted for this purpose. Their demand levels were estimated by Dual Time Representation analyses, which dissect tasks into elementary steps, linking each step to the cognitive process it is assumed to activate. All tasks were piloted on males, typically-developed and with high-functioning Autism Spectrum Disorder in order to identify effects specifically related to autism. Tasks 4 and 5 were additionally piloted on a participant with Fragile X Syndrome and intellectual disability. Following is a brief description of the five tasks and the main results:
   Task 1: Smooth Pursuit of a Dynamic Target (Chapter 6). Ongoing movement and colour changes within the target were associated with an amelioration of smooth pursuit (higher gain and lower number of saccades) in higher-velocity pursuit, and with higher pupillary constriction. The ASD group had inferior smooth pursuit relative to the matched control sample and higher pupillary constriction across conditions, which significantly decreased with dynamic target saliency.
   Task 2: Smooth Pursuit with Distractors (Chapter 7). No distractor effect was detected in the TD or ASD group, probably because of the metrics of the experiment. Smooth pursuit asymmetries were detected and compared with those in Task 1. Asymmetries showed constancy across paradigms.
   Task 3: Reflexive Responses to Gaze and Arrow Cues (Chapter 8). More time was devoted to explore the arrow stimuli. Idiosyncratic responses to cue rather than to target were moderately associated with readiness to respond. For validly cued trials, responses were faster at shorter SOA (congruency effect) but longer at longer SOA (inhibition-of-return effect). Results were unrelated to autism traits in the TD group. The ASD group showed no inhibition-of-return effect.
   Task 4 – Tapping tasks on the Corsi Board (Chapter 9). Six parameters of task demand were evaluated indirectly by their reduction in error sequences. Four parameters (Length, Angularity, Clutter and Crossing) seemed to contribute largely to error commission. The ASD group performed similarly to controls. The participant with FXS committed many perseverative and random errors, indicative of poor task planning.
   Task 5 – Continuous Performance Test (Chapter 10). In the normative sample, efficiency increased with age (faster responses, better discrimination between signal and noise, less risky response style). TD and ASD participants had longer response time as the test progressed, evidence of diminishing sustained attention. The FXS participant had long response times, suggestive of slower processing speed, but normal sustained attention.