Eye Gaze Cueing In Fragile X and Autism: A Pilot Study

Background: Generally, people rely on the ability to detect and follow another individual’s eye gaze to infer valuable social information such as turn taking in conversation, a shift in attention, or to signal to an object.  Individuals with neurodevelopmental disorders such as Autism Spectrum Disorder (ASD) and Fragile X Syndrome (FXS) show specific deficits in gaze following and joint attention, look less at social stimulus, and fixate less on the eye region.  In individuals with FXS, eye gaze avoidance has been theorized to be due to hyperarousal and anxiety.

Objectives: This pilot study investigates two questions: (1) Can we effectively test low-functioning individuals with FXS and ASD in a computerized social and non-social attention tasks that requires gaze to the eye region and manual reaction times?  (2) Do individuals with FXS and ASD show similar patterns of using social (eye gaze, hands) and nonsocial cues (arrows) to direct their attention?

Methods: Individuals with ASD with cognitive impairment, FXS, or neurotypical (NT) development between 13 and 40 years participated in a social and non-social cueing task.  Three types of stimuli were used: faces, signs with arrows or hands.  In the baseline condition, the face remained still and neutral, the signs did not change, and the hands pointed forward; a target was then presented on either the right or left side of the cue.  In the test trials, the eyes on the face stimuli shifted to either the right or left, the sign arrows pointed to the left or right, and the hands pointed to the left or right.  In the congruent condition the direction of the cue matched the target while in incongruent trials, the target appeared on the opposite side of the cue.  Participants were instructed to press a button with their right or left hand that matched the side of the target appeared.  Practice trials were administered to ensure all participants understood and could perform the task.  

Results: Failure to complete the task was related to verbal skill in the ASD group; as well, more subjects in the ASD group were non-compliant with task procedures.  Preliminary analyses indicate that the FXS group were slower to react to the target and did not benefit from congruent cue-trial pairings.  The FXS group also displayed more target detection errors.  The ASD and NT groups showed a similar pattern of reaction time to both congruent and incongruent trials and were faster at detecting the target during congruent cues.  

Conclusions: Preliminary results suggest that the FXS group is slower to react to a target regardless of whether it is congruent or incongruent with the cue.  The ASD and NT groups’ reaction time speed was facilitated by congruent cues.  Further analysis will investigate differences in reaction times between social (eyes, hands) and nonsocial stimuli (arrows).  We will also analyze IQ scores to find the cut-off IQ score for successful completion of the cueing task.