posted on 2017-03-23, 03:36authored byEsther 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.