Perspective-taking based insights into Theory of Mind: An ERP study

Title

Identifier

d_2009_2013:e4f5ee791871:10963

identifier

10899

Creator

Axel, Elizabeth Simon,

Contributor

Ray Johnson, Jr

Date

2010

Language

English

Publisher

City University of New York.

Subject

Abstract

Theory of Mind (ToM) is defined as the ability to make inferences about another person's mental state. One account of ToM, Simulation Theory, posits that this ability is accomplished by using one's own mental processes as a model for the other person's mind. This is accomplished in a serial manner by first accessing the processes related to the self before switching to taking the perspective of the other. Hemodynamic imaging studies of ToM have provided evidence that self and perspective-taking processes depend on different brain circuits but cannot identify the temporal aspects of the processes. To determine if these processes occur in the posited serial manner, event-related potentials (ERPs) were recorded while participants made evaluations either from their own perspective or from the perspective of another person (i.e., Task: Evaluation, Perspective-taking). The relatedness of the person (target) of the evaluations (i.e., Relatedness: Self, Close Other, CO, Non-Close Other, NCO) was also varied to determine if the brain areas posited to be involved in the processing of the self would be activated differentially. Thus, a three-stage, serial process was hypothesized, suggesting that the perspective-taking process requires an initial anchoring in the self, a decoupling of different perspectives (i.e., self and other) and then a late stage in which the other's perspective is maintained in order to make a decision.;The results showed that RTs were similar across conditions. Recordings from 83 scalp sites revealed differential patterns of activation as a function of both Task (Evaluation, Perspective-taking) and Relatedness (Self, CO, NCO). Consistent with the "serial hypothesis," the ERP results provided evidence of three temporally distinct stages during the decision process when the various evaluation and perspective-taking tasks were compared in the electrodes corresponding to TPJ. When Evaluation and Perspective-taking judgments were compared, a first stage (i.e., 200--350 ms) was found in which there were no ERP differences as a function of Task, in accord with the idea that perspective-taking processes require an initial grounding in the self. In contrast, during this first stage, effects were seen as a function of Relatedness in which judgments about Self were more negative-going than judgments of CO or NCO. A second stage (400--600 ms) became apparent in which the lack of ERP differences between Evaluation and Perspective-taking tasks continued but now the Relatedness effects disappeared. That is, during this middle stage, the ERP activity from all conditions was similar. As a result of its timing, being interposed between the early and late stages, this middle stage may reflect the hypothesized decoupling process (i.e., shift from self to other) that was posited to occur between the self and perspective-taking stages In the third stage (700--850 ms) the ERP activity elicited during perspective-taking differed from that in evaluation tasks due to the addition of a negative slow potential over the temporal-parietal junction (TPJ). Relatedness effects returned in this later stage, although in this time period judgments about the self elicited more positive-going ERPs than judgments of CO or NCO. In addition, the results revealed that self-referential evaluations were marked by greater ERP activity over occipital and mid-frontal scalp very early after stimulus onset (i.e., 70--360 ms). Increased activity at these locations has previously been shown to reflect the level of attention devoted to stimuli indicating that self-referential evaluation engendered the highest levels of overall attention. Finally, although not addressed in models of ToM processes, the results revealed that the differences in use of control processes varied as a function of both task and the object of the decision. Specifically, compared to evaluation tasks, perspective-taking tasks elicited a larger pre-response negativity (PRN), which has been linked to the use of goal-oriented, strategic monitoring processes. Moreover, within each of these tasks, there were graded effects on the relatedness dimension in which judgments about the self required the least strategic monitoring, followed by the close other, with non-close other requiring the most. In addition, the amplitude of the medial frontal negativity (MFN), which follows the response and has been shown to reflect the residual conflict following a response, also varied as a function of both task and the object of the decision. That is, perspective taking judgments elicited larger MFNs (i.e., greater residual conflict) than evaluations and judgments about the self elicited the smallest MFN with larger MFNs for close other judgments and the largest MFNs for non-close other judgments. (Abstract shortened by UMI.).

Type

dissertation

Source

2009_2013.csv

degree

Ph.D.

Program

Psychology

Item