The neuroscience of social understanding John Barresi Dalhousie University

1. The neuroscience of social understanding John Barresi Dalhousie University Evaluation of Three Theories of Social Understanding Background Neuroscience of Social Understanding • Evaluation of Theory Theory: Positive aspects of the theory. • TToM works fairly well on standard ToM tasks involving stories or videos. The pSTS (TPJ) which is typically involved in the complex analysis of biological motion fits the idea that TT is predominantly based on 3rd-person information, that can also be applied to self. • The Anterior Paracingulate (MPFC) has been interpreted as involving “decoupling” of second-order representations, and here applies to self and other, again fitting the theory. • Evaluation of Theory Theory: Negative aspects of the theory • When we consider emotional intentional relations and action intentional relations TT breaks down: • For emotional understanding, empathy seems an important factor and degree of empathy correlates with responses in Anterior Insula and ACC areas typically associated with self-awareness of body state • However, even findings apparently congruent to TT do not entirely fit the theory as Inf. Parietal (TPJ) shows hemisphere differences, and the MPFC may be more self (or self & other) oriented. • Evaluation of Simulation Theory: Positive aspects of the theory • Many of the findings for all three kinds of intentional relations seem to depend on brain regions known to be intimately involved in self activity, thus activity in these regions may be on loan for understanding others • Empathy ratings correlate with activation for others in some of the regions associated with self-consciousness • Observing or thinking about others seems to activate these regions for simulations • Evaluation of Simulation Theory: Negative aspects of the theory • Activations in the APC or MPFC seem to respond equally to self and other, suggesting a more cognitive than empathic mechanism, similar to the “decoupling” mechanism of TT, or Intentional Schema of IRT. • The contrast between left and right hemisphere effects in the Inferior Parietal (TPJ) - and possibly elsewhere (e.g., Anterior Insula) - suggest a self-other differentiation that might involve distinct mechanisms for social understanding. • Evaluation of Intentional Relations Theory: Positive aspects of the theory • It is structured to make distinctions between: • Three kinds of intentional relations (action, emotion and epistemic), which match results associated with different brain regions. • First-person, 3rd-person and shared representations, which are also associated with different brain regions. • Levels of social understanding with phylo- and onto-genetic import • It has been used by neuroscientists to interpret in a functional manner the different regions involved in imitation. • Evaluation of Intentional Relations Theory: Negative aspects of the theory • It is perhaps too flexible, particularly in its concept of an intentional schema that can be used for any “matched” findings, regardless of the particular brain regions involved in the match. • It has not been explicitly tested against the alternative theories. • The Matching Problem of Social Understanding • How can we attribute the same meaning to actions of other individuals that we attribute to our own actions, when the first-person information that we have of our own actions is radically different from the third-person information that we have of the actions of others? • Three Theories of “Theories of Mind” (ToM) • Theory Theory (TT) - (e.g., Carruthers, Fodor, Gopnik, Leslie, Perner; Baron-Cohen, Frith & Frith) • Simulation Theory (ST) - (e.g., Gordon, Goldman, Harris; Gallese & Goldman) • Intentional Relations Theory (IRT) - (Barresi & Moore, “Intentional relations and social understanding,” Behavioral and Brain Sciences, 1996, 19: 107-54; e.g., Decety, Iacoboni, Jeannerod) • Two Theories and the Matching Problem • Theory Theory - According to TT, we have no special knowledge of self, and must use a single abstract - possibly innate - conceptual system to understand our own as well as others’ minds. • Simulation Theory - According to ST, each of us has direct knowledge of our own minds, and we can use this knowledge to model or simulate other minds. • The Matching Problem - Neither TT nor ST provides an adequate account of how we ever come to apply the same concepts to self and other, given the differencebetween our 1st-person access to our own minds and our 3rd-person access to the minds of others. • A Solution to the Matching Problem • Somehow we ‘match’ the 1st-person information of our ownactions to the 3rd-personinformation of the same actions by others. • Given this matching process, we can give the same meaning to an action whether it is produced by self or other. • And we can access that same meaning using 1st -person information in the case of self, and 3rd - person information in the case of the other. • Neuroscience using ToM tasks • The focus of these studies is on determining brain regions functionally involved in the interpretation of complex stories of social interaction that are visually or verbally presented. Two brain regions are most active in these studies: 1) Posterior Superior Temporal Sulcus (pSTS) or the Temporal/Parietal Junction (TPJ); 2) Medial Prefrontal (MPFC) or Anterior Paracingulate (APC). • MPFC (or APC) pSTS (or TPJ) • may provide “decoupled” may provide the • (2nd order) representations analysis and • of intentional relations (IRs) representatlon • of IRs • From Frith & Frith (2003) Regions for analysis and representation of self and other overlap (from Decety and Sommerville, 2003) How TT can work for complex epistemic ToM tasks • pSTS (or TPJ) analyzes and represents animate activity and IRs based mostly on visual or 3rd person information. TT could avoid the matching problem by positing that IRs of self and other are both analyzed in a behavioristic (or 3rd person) mode. MPFC (or APC), based on these analyses, and possibly using an innate ToM, could then provide “decoupled” (2nd order) representations of intentional relations of agents, whether they be of self or other (or jointly self and other). • A problem for TT that ST can handle • The MPFC (and perhaps the TPJ) is activated in cases of self-representation that seem not to be based entirely on 3rd person information about the self. • Furthermore, the frontal region and other regions along the midline have been postulated to be part of a system for representation & regulation of self. • So, perhaps, the MPFC generates a 2nd order representation of other’s mental states, through prior association between a 3rd person behavioral analysis that applies somewhat equally to self and other in the TPJ and a simulation of 1st person components of mental states found in the rest of the self-system. • fMRI responses for • anticipated shock • for self and other Empathic ability • correlated with • fMRI activity • Green self • Red other • From Singer, et. al. (2004) • How ST can handle affective IRs better than TT • The conscious “feeling self” regions of brain activity can not only anticipate and interpret affective IRs in self but also in others (and in inanimate objects). • At the same time, sensory 1st person information, that may (or may not) be conscious, can be used to distinguish self from other. • Consistent with ST, dispositionally empathic individuals engage in more active “simulations” than less empathic individuals, a finding not expected on TT’s more cognitive account. • IRT can handle both epistemic IRs and affective IRs • at least as well as TT & ST. In addition, it provides, in the intentional • schema, a concept that can be applied also to action IRs. • Iacoboni, Kaplan & Wilson (in press) developed an account of imitation which • explicitly uses IRT at the functional level of their model (see figures to right). • Figure to right: The neural architecture for imitation mapped onto the • functional elements of Intentional Relations Theory. Each box has three • types of descriptions: an anatomical description, a functional description, • and an icon representing Intentional Relations Theory. Intentional Relations Theory • Intentional Relations (IRs) connect an agent (or agents) to an object through a relation existing in virtue of an agent’s sensorimotor, emotional/motivational and cognitive capacities. • Examples of first order intentional relations • Jamie chases the cat (action) • Mackenzie fears the dog (emotion) • Columbus sees land (epistemic) • Examples of second order intentional relations • Fiona thinks that she is in love with Colin. • Fiona thinks that Mary is in love with Colin. • Fiona exhibits ‘social understanding’ of intentional relations of self and other. • First Person Information:Provides an“inner”perspective of the IR, which emphasizes the objectand IRto it, while deemphasizing information about agent. • Third Person Information:Provides an “outer” perspective of the IR, which emphasizesthe agentof the IR, but deemphasizes information relating the agent to the object. • Intentional Schema • Is an intermodal perceptual and conceptual structure that can coordinate and integrate first- and third-person sources of information about object-directed activities into representations that link agents to objects through intentional relations. • It combines the internal or ‘subjective’ aspect of an agent’s intentional orientation toward an object with the external or ‘objective’ aspect of an agent’s behavioral activities. • Four levels of Social Understanding of Intentional Relations • Level 1: 1st-person information of IRs of self are kept distinct from 3rd-person information of IRs of the other, so the intentional schema does not apply. • Level 2: Matching occurs between 1st-person information of self and 3rd-person information of other, when both are in the same/similar IR. (Understand shared IRs) • Level 3: Matching occurs between current 1st or 3rd person information and imagined co-ordinate information of IRs. (Understand embodied IRs of self or other) • Level 4: Matching occurs between imagined 1st and 3rd person information of IRs. (Understand mental states of self or other) Conclusions • Neuroscience research on social understanding provides a rich data base from which to evaluate the three types of theories of ToM. • All three theories have something to offer in explaining empirical results and might be modified to fit current data. • Intentional relations theory – perhaps due to its flexibility - seems to find more support and fewer problems than TT or ST. • Further testing using contrasting predictions where possible between the theories could lead to significant progress in determining how humans (and other organisms) engage in social understanding. Bibliography Barresi, J., and Moore, C. (1996). Intentional relations and social understanding. Behavioral and Brain Sciences, 19, 107–154. Decety, J., & Sommerville, J. A. (2003). Shared representations between self and other: a social cognitive neuroscience view. Trends Cogn Sci, 7(12), 527-533. Frith, U & Frith, C. (2003) Development and neurophysiology of mentalizing. Phil. Trans. R. Soc. Lond. B (2003) 358, 459–473. Iacoboni, M., Kaplan, J. & Wilson, S. (in press) A neural architecture for imitation and intentional relations. In: Nehaniv C, Dautenhahn K, editors. Imitation and social learning in robots, humans and animals: Behavioural, social and communicative dimensions. Cambridge, UK: Cambridge University Press. Singer,T., Seymour, B., O’Doherty, J., Kaube, H., Dolan, R., & Frith, C. (2004). Empathy for pain Involves the affective but not sensory components of pain. Science, 303, 1157-1162.