Virtual reality may reveal new clues about autism social difficulties
By: Jon Brock
Tags: Psychology, Autism, Virtual Reality

In 2013, a team led by Leonhard Schilbach, now at the Max Planck Institute of Psychiatry in Munich, Germany, published a new manifesto for social cognition research. These researchers argued that social cognition should be investigated using a ‘second-person neuroscience’ approach, in which behavior and brain responses are measured while people engage in reciprocal interactions.

This emerging field offers exciting possibilities for understanding autism. But it also presents serious challenges: Experimental investigations require precise control of the conditions so they can be repeated and manipulated consistently. Achieving this control in the context of a realistic social interaction is far from straightforward.

In a review article published earlier this year, we addressed these issues. We focused on studies of joint attention, which involves both responding to your partner to attract his attention, and initiating joint attention, by guiding that person to an object or location of interest. Joint attention is important in the development of language and social skills, and a delay in its development is one of the most reliable early signs of autism.

One approach used in a number of studies has been to measure brain responses while participants are engaged in a joint-attention game with another person, either face to face or through a live video feed. However, this relies on the partner behaving consistently for all participants.

Differences in the brain responses of people with and without autism may reflect differences in the neural mechanisms of joint attention. But they could just as well reflect variation in the behavior of the partner, or in the participants’ sensitivity to other social cues, such as smiles or eyebrow raises, from the partner.

To address these issues, we and other researchers have replaced the human partner with a virtual partner, or avatar, whose behavior is controlled by a computer.

In our own studies, participants interact with an animated virtual character called ‘Alan’ whose face appears in the center of a computer screen. We use an eye tracker to see where on the screen the participant is looking, and program Alan to respond to her eye movements. This gives us complete control over the interaction.

The participant works with Alan to catch a burglar who is hiding in one of six houses on the screen. Each trial begins with both Alan and the participant searching the houses. If the participant finds the burglar, she initiates joint attention, guiding Alan to the burglar by making eye contact and then looking at the correct house. If, on the other hand, Alan finds the burglar, he initiates joint attention and the participant responds.

The game requires participants to coordinate their behavior with Alan, make use of eye contact and flexibly assume different roles in the joint-attention process.

The search phase of our task also adds a complexity that is absent from other studies. Because Alan makes many eye movements during the trial, the participant has to decide whether a particular eye movement is intended to guide her to the burglar or is simply part of Alan’s ongoing search.

We have found that participants respond much faster if we remove the search phase so Alan’s eye movements always indicate the burglar’s location. This suggests that what we call ‘intention monitoring’ — working out whether a cue such as an eye movement is intended to be communicative — is an important part of joint attention.

In research published in April, we used this task with a group of adults with autism. Overall, they made slightly more errors than controls did. They were also slower to respond to the avatar’s eye-gaze cue, but were just as fast as controls when we replaced Alan’s eye-gaze cues with an arrow pointing to the burglar’s location.

This finding suggests that the difficulties of adults with autism are specific to the social interaction involved in the task, and cannot be explained by other factors that might affect performance — such as the ability to orient attention or control eye movements.

Our findings suggest that subtle joint-attention difficulties continue into adulthood, at least for some people with autism. This contrasts with evidence from other studies suggesting that children and adults with autism have no difficulty responding to eye-gaze cues on a computer screen.

We think this may reflect the intention-monitoring component of our task, which makes it more akin to a real-life interaction.