Alma Gharib1, Daniela Mier1,2, Ralph Adolphs1, Shinsuke Shimojo1
1 Division of Biology Caltech, Division of Computation and Neural Systems, Caltech,US.
2 Department of Clinical Psychology, Central Institute of Mental Health, Mannheim,Germany
Preference and gaze interact in a positive feedback loop to produce a phenomenon known
as the ‘gaze cascade’ effect. In the few seconds before a decision is made, a gaze bias occurs
toward the stimulus that is eventually chosen. This gaze cascade is especially robust in tasks
that involve face preference decisions. Autism is a pervasive developmental disorder where
deficits in evaluating and making social judgments about faces occur. Persons with autism
typically have inattention to faces and direct gaze aversion. The present study was set up to
examine whether these known aberrations in visual face processing interfere with
preference choice decision making in ASD, reflected in a deviant gaze cascade pattern.
4 ASD subjects and 3 age and gender matched healthy controls (HC) performed a 2‐
alternative forced‐choice task, while their eye‐gaze was tracked. Their task was to select
the stimulus they prefer by pressing a button under a free viewing condition. Stimulus types
consisted of faces and natural scenes.
First, we were able to replicate the findings of a gaze cascade in the HCs, already with this
temporary group size. Interestingly, the known gaze aversion for faces in ASD did not
interfere with the gaze bias toward the to‐be‐chosen picture at decision time, independent
of stimulus type. Indeed, the probability of a gaze bias towards the chosen picture at 40 ms
before response was even significantly higher in the autism group than in the HCs (p< 0.001
for each of the conditions). On the other hand, the course of their viewing patterns clearly
deviated from that of the HCs and is not in agreement with the typical gaze cascade. These
findings implicate that while gaze is clearly involved in preference formation in autistic
subjects, the psychological process that leads to the decision may differ from that of HCs.