Abstract
Autism is a socio-communication brain development disorder. It is marked by degeneration in the ability to respond to
joint attention skill task, from as early as 12 to 18 months of age. This trait is used to distinguish autistic from nonautistic.
In this study Near infrared spectroscopy (NIRS) is being applied for the first time to study the difference in
activation and connectivity in the frontal cortex of typically developing (TD) and autistic children between 4-8 years of
age in response to joint attention task. The optical measurements are acquired in real time from frontal cortex using
Imagent (ISS Inc.) - a frequency domain based NIRS system in response to video clips which engenders a feeling of joint
attention experience in the subjects. A block design consisting of 5 blocks of following sequence 30 sec joint attention
clip (J), 30 sec non-joint attention clip (NJ) and 30 sec rest condition is used. Preliminary results from TD child shows
difference in brain activation (in terms of oxy-hemoglobin, HbO) during joint attention interaction compared to the nonjoint
interaction and rest. Similar activation study did not reveal significant differences in HbO across the stimuli in,
unlike in an autistic child. Extensive studies are carried out to validate the initial observations from both brain activation
as well as connectivity analysis. The result has significant implication for research in neural pathways associated with
autism that can be mapped using NIRS.
