Micaela Jacobson

Thesis Supervisor: Dr. Adam Cohen Department of Psychology, Western University

In the present study, two competing hypotheses were tested regarding the presence or absence of "privileged circuitry" between areas of the brain processing social cues (gaze) and areas dealing with Theory of Mind (ToM), the ability to explain and predict behaviour in terms of mental states. It was hypothesized that if specialized circuitry were present, then gaze cues embedded in a ToM task would have a stronger effect on ToM reasoning compared to non-social cues (arrows). Adult participants viewed animations of false belief scenarios and completed a computerized task in which they considered where an agent with a false belief would search for an object. Before they responded, a gaze or arrow cue briefly appeared. Participants indicated whether the agent was standing where he or she expected to find the animal, and reaction times and accuracies were recorded. The “privileged circuitry” hypothesis was not supported by the data. This study provided evidence for the null hypothesis, suggesting that brain connectivity between areas involved in social functioning is more general-purpose than we predicted.

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Our purpose was to distinguish between two competing hypotheses regarding the presence or absence of “privileged circuitry” between areas of the brain dealing with Theory of Mind and areas processing social cues (gaze). “Privileged circuitry” could entail thicker fibers or more myelination, allowing for faster conduction.

ToM has been has been examined through variations of the False Belief Task (Baron-Cohen et al., 1985). Participants have been shown to reason faster about beliefs than physical representations (maps) depicting the same information (Cohen & German, 2010).

Previous studies examining social attentional cueing through the Posner cueing paradigm found no difference in reaction time based on cue type (Posner, 1978).

ToM and social cueing have never been examined together within one experimental design. By providing a salient social context (not present in the Posner cueing paradigm), we intended to reveal the presence of “privileged circuitry.”

The above visual depicts screenshots of the animations presented to participants over each trial. Images belong to Dr. Adam Cohen.

An interaction was hypothesized between cue type and cue congruency. Congruent gaze cues were expected to draw participants’ attention in the correct direction, facilitating reaction time, whereas incongruent gaze cues were expected draw participants’ attention in the opposite direction, slowing reaction time. Arrow cues were expected to show weaker cueing effects due to their lack of social significance.

PARTICIPANTS Participants were 38 adult males and 50 females from the undergraduate participant pool (Mage = 18.36). Participants received a course credit for their participation.

PROCEDURE Participants were instructed to view and respond to the following animated scenarios.

The Posner Cueing Paradigm (Posner, 1978)

The False Belief Task (Baron-Cohen et al., 1985)

2. The rabbit switches boxes as the child returns (true belief, top), or while the child is absent (false belief, bottom.)

3. The animal is hidden in one of the two boxes.

4. A fixation cross appears, followed by a gaze cue or an arrow cue (can be congruent or incongruent with where the child is expected to search for the rabbit).

1. A child places a rabbit in one of two boxes and then leaves the room.

5. The child reappears standing behind one of the two boxes. Participants press “Y” if the child expects the rabbit to be in that box, and “N” if he expects it to be in the other box.

Eye Gaze Arrows

Participant Reaction Times on a Theory of Mind Task after exposure to Gaze cues or Arrow cues

Condition

Reaction Time (s)

DESIGN

Congruent True Belief

Incongruent True Belief

Congruent False Belief

Incongruent False Belief

Time (s)

The interaction between cue type and congruency was found to be non-significant by a mixed factorial ANOVA, F (1, 86) = 1.52, p > .05, (failed to reject the null hypothesis). The null hypothesis was further supported by Bayesian analysis.

Congruent True Belief

Incongruent True Belief

Congruent False Belief

Incongruent False Belief

Figure 1. Reaction times on Theory of Mind task for participants across the eight experimental conditions. Given that cue type was a between- subjects condition, participants experienced only four of the eight experimental conditions. Bars depict one standard deviation.

In the present study, we intended to distinguish between two competing hypotheses regarding the presence or absence of “privileged circuitry” between brain areas involved in social cue processing (gaze) and areas dealing with ToM.

Our results ultimately supported the null hypothesis. They implied that the connections between areas that process social cues (gaze) and areas that deal with ToM are more general-purpose than we predicted, and respond to all directional cues in an equivalent manner regardless of social significance.

It is important to clarify that even though our results supported the existence of generalized connections between these areas, it is still possible that these areas themselves are highly specialized.

I would like to thank my supervisor, Dr. Cohen, for his advice and assistance throughout the research process. I also want to thank the lab manager, Laura Zielinski, for her large contribution to the data collection process.