Measuring visual perspective taking in the brain with avatars and arrows: Which question are we asking?

Visual perspective taking neural processing in forensic cases with high density EEG

This EEG study aims at dissecting the differences in the activation of neural generators between borderline personality disorder patients with court-ordered measures (BDL-COM) and healthy controls in visual perspective taking. We focused on the distinction between mentalizing (Avatar) and non-mentalizing (Arrow) stimuli as well as self versus other-perspective in the dot perspective task (dPT) in a sample of 15 BDL-COM cases and 54 controls, all of male gender. BDL-COM patients showed a late and diffuse right hemisphere involvement of neural generators contrasting with the occipitofrontal topography observed in controls. For Avatars only and compared to controls, the adoption of Self perspective involved a lower EEG activity in the left inferior frontal, right middle temporal cortex and insula in BDL-COM patients prior to 80 ms post-stimulus. When taking the Other-perspective, BDL-COM patients also showed a lower activation of superior frontal, right inferior temporal and fusiform cortex within the same time frame. The beta oscillation power was significantly lower in BDL-COM patients than controls between 400 and 1300 ms post stimulus in the Avatar-Other condition. These results indicate that BDL-COM patients display both altered topography of EEG activation patterns and reduced abilities to mobilize beta oscillations during the treatment of mentalistic stimuli in dPT.

Intensionality is more cognitively demanding than false belief in adults: evidence from a non-inferential sentence-reading task

Children are said to understand false belief if they can appreciate an agent's wrong description of an object as a result of misinformation, and intensionality if they can appreciate and switch between alternative descriptions from different epistemic viewpoints. Most previous studies have investigated the developmental trajectories of these capacities in the age range from 3 to 10 years aiming to discern their conceptual nature. The present research examines whether intensionality incurs lower performance accuracies and longer response times than false belief in adults, using a task in which participants read sentences that explicitly state an agent's beliefs. Experiment 1 showed that participants were less accurate in rejecting verbal probes that contradicted an agent's alternative than false thoughts about objects. Experiments 2 and 3 replicated this finding using thoughts about object identities but not properties. These results suggest that compared to false belief, intensionality is cognitively demanding for adults to process because of the availability of more than one identity candidate under the agent's perspective.

Reduced spontaneous perspective taking in schizophrenia

Judgments about another person's visual perspective are impaired when the self-perspective is inconsistent with the other-perspective. This is a robust finding in healthy samples as well as in schizophrenia (SZ). Studies show evidence for the existence of a reverse effect, where an inconsistent other-perspective impairs the self-perspective. Such spontaneous perspective taking processes are not yet explored in SZ. In the current fMRI experiment, 24 healthy and 24 schizophrenic participants performed a visual perspective taking task in the scanner. Either a social or a non-social stimulus was presented and their visual perspectives were consistent or inconsistent with the self-perspective of the participant. We replicated previous findings showing that healthy participants show increased reaction times when the human avatar's perspective is inconsistent to the self-perspective. Patients with SZ, however, did not show this effect, neither in the social nor in the non-social condition. BOLD responses revealed similar patterns in occipital areas and group differences were identified in the middle occipital gyrus. These findings suggest that patients with SZ are less likely to spontaneously compute the visual perspectives of others.