Linking movement execution and perception in Autism Spectrum Disorder

Although social and communication deficits are the main diagnostic feature of
ASD, movement abnormalities are characteristic for this clinical
population.Moving in an atypical manner is thought to contribute to social and
communicative difficulties in ASD. Every day human communication relies heavily
on communicative actions, such as co-speech gestures, action demonstrations or
pantomimes. In order to convey the communicative intention, actors tend to
exaggerate certain kinematic features, which allows the underlying intention to
be read and the meaning to be understood. In other words, communicative success
may be partially explained by how the gesture is produced at a kinematic level.
Difficulty in producing pantomimes is well known in children with ASD, however
there is currently little research describing the kinematics of pantomimes
production in ASD adults. If communication relies on exaggerating kinematics,
then atypicalities in gesture kinematics may interfere with the communicative
success of the gesture. Therefore it is important to determine whether gesture
production in adults with ASD is characterized by typical or atypical kinematic
profiles.

Studies have also shown that individuals with ASD sometimes show deficits in
understanding gestures, and often have difficulty using kinematic information
for action understanding. Particularly, children and adults with ASD fail to
use kinematic cues for predicting a future action and the end goal of an
action. An open question is whether the difficulties in action understanding
are underlined by the inability to process fine-grained movement kinematics.
Our previous study showed that in neurotypical adults communicatively intended
pantomimes are produced with an exaggerated kinematic profile. Specifically,
spatial (such as overall size segmentation of individual movements) and
temporal (such as peak velocity and use of gesture holds) features were
increased in a more- compared to less-communicative context. This kinematic
exaggeration leads to improved comprehension by observers. When observers must
quickly interpret the meaning of the gesture, the use of holds led to better
recognition performance. Here we will address whether individuals with ASD are
able to comprehend pantomimes, and whether kinematic exaggeration aids their
comprehension.

Furthermore, understanding how the brain of an ASD individual utilizes movement
information to inform action recognition is an important piece to the puzzle.
As it is currently unclear whether the kinematic modulation present in
communicatively modulated actions will be noticed by individuals with ASD,
neuroimaging can provide additional clarification about how kinematics are
processed during semantic processing. Semantic recognition of pantomimes
requires the so-called fronto-parietal *action observation network* that is
sensitive to processing human movements. Specifically, connectivity between
distinct areas of the network may be important in order to integrate various
sources of information, such as movement goals, fine grained human movement
kinematics, or use of objects. Previous studies found reduced connectivity in
ASD, also specifically in the action observation network. This suggests that
this atypical connectivity may be a unique marker of the ability to understand
the actions of others. It remains an open question how differences in brain
connectivity underlie the ability to take advantage of communicatively
modulated signals for easier semantic recognition.

1) Assess whether individuals with ASD perform pantomimes with similar
kinematics to typical individuals, and whether the typicality of their
kinematics can be explained by motor impairment.
2) Assess whether individuals with ASD are able to utilize kinematic modulation
to support semantic comprehension of pantomimes.
3) Elucidate the network connectivity topology underlying semantic
comprehension of pantomimes, and assess whether differences in network
connectivity can predict differences in the use of communicative kinematic
modulation between autistic and typical individuals.

The study will be implemented in two experiments. The first is a
cross-sectional behavioral study of approximately 30 minutes. The second part
will utilize a task-based functional magnetic resonance imaging approach and
will require 1 hour. In the scanner, we will collect T1 anatomical scans and
implement a cross-sectional semantic comprehension task. The study will last
approximately three hours, including breaks between study parts, and will take
place at the Donders Centre for Cognitive Neuroimaging (DCCN). Participants
will be brought to the specific locations within the DCCN by the experimenter,
as well as to the cafeteria for breaks.

Participants must travel to the Radboud University for assessment, and risks
include discomfort in the MRI scanner (Part 2), or fatigue experienced through
the course of the day. All assessments will be collected in one day in order to
reduce burden of travel, while fatigue will be reduced by providing longer
beaks in between individual tasks. *
Although there is no immediate therapeutic or clinical benefit of this study,
the present research allows us to form a more cohesive image of how certain
symptoms in the autism spectrum relate to one another, and shed light on the
neurocognitive mechanisms of ASD. This can lead to improved therapies and more
effective patient-caregiver interactions.