Frontal cortex involvement in the theory of mind with research evidence

1. FRONTAL LOBES AND THEORY OF MIND
Presented by
Dr. M. Ramya Maheswari
Asst Professor and Head ,
Department of Psychology,
Ethiraj College For Woman

2. INTRODUCTION
Theory of mind (ToM) refers to a person’s ability to infer the intentions and mental states of others (Leslie 1987). Most
experimental attention has focused on the emergence of this skill in children (and in autism, in particular) because it is
considered to be one of the
A commonly used test of theory of mind is the false-belief task. In a typical version of the false-belief task, person A places
an object in a cupboard and leaves the room; person B enters, puts the object in a different location and leaves the room;
person A re-enters, and the participant is asked where person A will look for the object. Children have been found to improve
on false-belief tasks from around 3 to 5 years of age (Wellman et al. 2001), and performance is not culture-specific –
European, North American, East Asian, Australian and African children have all been found to acquire understanding of
others’ beliefs at around the same time (Wellman et al. 2001). There is some evidence to implicate the frontal cortex, and
other regions, explicitly in ToM task execution .
There is also evidence to suggest a role for this region in autism, a developmental disorder that has three defining
characteristics – social abnormality, language abnormality, and stereotypical and repetitive patterns of behaviour (Frith 1989)
– but this evidence is patchy at best.

3. BRAIN AREAS
Happe and her colleagues (Happe 1999; Happe et al. 1999) have suggested that individuals with damage to the
right hemisphere will show impaired ToM but good reasoning, because damage to the right hemisphere causes
impairments in social behaviour and thinking similar to those seen in children with impaired theory of mind
(Happe et al. 1999).
Using the understanding of stories and cartoons as a measure of ToM, Happe et al. investigated the
performance of patients with right hemisphere lesions and a group of healthy controls. The right hemisphere
patients were significantly worse at understanding material that required the attribution of mental states (but
not material that was non-mental in nature). A group of patients with left hemisphere damage performed no
worse on the mental than on the non-mental material.
A resting EEG study of social behaviour in high-functioning autistic children found that children who were socially
impaired showed greater resting right frontal asymmetry, whereas the children who had fewer symptoms of social
impairment – but did report social anxiety, distress and less satisfaction with interpersonal relations – showed greater
left frontal asymmetry (Sutton et al. 2005). This, suggests that the frontal cortices may play differential roles in
positive and negative emotion. It is also a more recent addition to the studies implicating the frontal cortex in autism,
social functioning and ToM.

4. RECENT EVIDENCE OF FRONTAL CORTEX INVOLVEMENT
The idea that the frontal cortex is involved in ToM was supported in a study in which patients with frontal lobe damage were
compared directly with patients with other types of brain injury. Frontal lobe patients were poorer than patients with damage to
other brain areas when making inferences about other people’s points of view (Stuss et al. 2001). This study also found that
frontal lobe patients were poorer than others at detecting deception (i.e. uncovering people’s real motives).
The finding is echoed in a study by Rowe et al. (2001), which asked thirty-one patients with unilateral frontal lobe lesions and a
control group to read a story in which the reader has to make inferences about the behaviour of the protagonist. For example, in
one story, a man and a woman are doing housework. The woman asks the man to put washing from the linen basket into the
washing machine and put powder in the powder tray. She tells him not to turn the machine on. The woman vacuums upstairs
and changes the bed. She puts the bedclothes in the machine and puts washing powder in a ball-shaped container and sets the
machine going. The machine oozes with soapsuds.
The participants are asked why the woman is surprised to see the soapsuds (the woman had acted on the false belief that the
machine did not contain washing powder). The task is designed to assess participants’ ability to infer false beliefs. Individuals
with left and right frontal cortex injury were impaired at answering this question and at answering questions on other false-
belief tests.

5. Perspective taking (how we think other people feel about the same circumstances or individuals) is an
important human skill because it helps us to understand, and to empathize with, others. A new study has
shown that taking a different view of the same person recruits different brain regions (Ruby and Decety
2004).
The researchers asked participants to either adopt their own viewpoint or that of their mother when
answering either a neutral or emotional question. PET was used to measure brain activation. They found that
blood flow differed between the first- and third-person perspective taking.
When participants responded as themselves, the somatosensory cortex was activated; when they imagined
how their mothers would respond, a series of blood flow changes in the frontal and parietal regions was
found.
Furthermore, the left temporal region was activated when the person responded in the third person to the
emotional question, whereas the somatosensory cortex was activated when the person replied as themselves
in the same condition.

6. ARE FRONTAL LOBES NECESSARY FOR THE THEORY OF MIND
A Case of GT :
A prominent explanation of ‘theory of mind’ suggests that the medial frontal lobe plays an essential role in
allowing people to mentalize in the way that theory of mind requires (Gallagher and Frith 2003). However, a
new single-case study challenges this view. Bird et al. (2004) studied patient GT, who had suffered brain
damage as a result of stroke. There was extensive bilateral damage to the medial frontal lobes exclusively.
GT showed the typical frontal lobe symptoms – impairments in planning and memory. However, there was
no evidence of impairment on theory of mind tasks, suggesting that the medial frontal lobe may not be
necessary for performing such tasks. Why , then, does neuroimaging evidence and some clinical
neuropsychological evidence suggest otherwise? Bird et al. suggest that this could be because the medial
frontal lobes are necessary for the acquisition of theory of mind but not for implementing theory of mind
functions