Free Choice Response Assessment Reveals Basic Cognitive and Sensorimotor Properties in Autism Spectrum Disorders

Background: Orienting response is associated with motivation and cognitive functions and can give insight into peculiarities of mental processes in ASD and be instructive for planning education and interventions. Unfortunately, most psychophysiological protocols require cooperation from subjects. We introduced a method that does not rely on verbal instruction and measures parameters reflecting basic sensorimotor and cognitive functions. A series of simple intuitive tasks are presented on a touchscreen, and within several minutes a comprehensive set of data is collected. Earlier studies showed high levels of correlation of acquired basic parameters with results of psychological testing, including adaptive behavior in typically developing individuals (TD).

Objectives: We tested the applicability of Free-Choice Response software (patent pending) to assess basic cognitive and sensorimotor functions in children with ASD and compare the results with TD and other clinical groups.

Methods: 20 children with ASD (16 boys, age 3 to 10 years) participated, two outliers with average response time over 10 sec were excluded. The TD group included 47 children 5 to 10 years of age (21 boys). All children were silently or verbally encouraged to “play” with the touchscreen. No detailed instruction was given, the adults in the room did not comment on the performance. During the first series the subject touched the colored disc on the screen so that it disappeared and appeared at a different location. The exposure was not limited. Free response time (FRT) and number of misses were recorded. In subsequent series the exposure time reduced progressively, the disc changed color, the disc of one color did not disappear after touching. In the last series, an array of discs was presented with only one color sensitive for touch. Corresponding changes in performance were recorded.

Results: Children with ASD demonstrated longer FRT (first series 2654 ms vs 945 ms, second series 2320 vs 742 ms; 2376 ms vs 886 ms; all p<0.00001) compared to TD children. Analysis of individual data revealed that longer FRT in ASD is controlled not by general slowness, but rather speed inconsistency and distraction periods. Children with ASD had on average more misses (in four series: 24 vs 1, 23 vs 8, 38 vs 11, 29 vs 10 respectively; all p<0.00001) Similar results, reported elsewhere, were obtained from comparison of ASD and other clinical groups (ADHD, learning disabilities, fragile X syndrome – each with a distinct profile). They reflect differential diagnostic potential of the method. The stereotypic behaviors called for a higher number of repetitive responses in ASD.

Conclusions: Free-Response Choice method can collect a large amount of relevant information within a short period of time. The obtained data translate into terms of basic sensorimotor and cognitive functions as well as level of motivation. It is one of few tools not requiring verbal instruction and in such a manner can be used with all populations including individuals with extremely low IQ and very limited cooperation.