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Understanding Others and the Self - What does brain maturation tell us about early Theory of Mind development and its relation to the emergence of a self-concept in early childhood?

Periodic Reporting for period 1 - ToMSelfLink (Understanding Others and the Self - What does brain maturation tell us about early Theory of Mind development and its relation to the emergence of a self-concept in early childhood?)

Reporting period: 2018-05-01 to 2020-12-31

Our human social interaction crucially relies on our ability to infer what other people have on their mind, referred to as Theory of Mind (ToM). Traditionally, ToM is thought to heavily rely on language and executive function and thus only develop around 4 years of age, when children begin to verbally reason about others' beliefs. However, a growing body of research shows that already preverbal infants seem to consider other people’s beliefs when predicting their actions. This has created a puzzle: Do infants already have a ToM? And if they do, why then do preschoolers still fail traditional verbal ToM tasks? ToMSelfLink asks which cognitive and neural processes underlie infant compared to verbal ToM tasks. We hypothesize that, instead of inferring other people’s thoughts and beliefs, infants’ own perspective may be biased by what other agents attend, and that the development of the self-concept then contributes to the emergence of different perspectives. Taken together, ToMSelfLink aims to reveal how infants and young children come to understand others, a core ability of human social cognition.
Neural basis of infant versus traditional verbal ToM tasks
We related children's performance in infant and traditional verbal ToM tasks with their cortical structure assessed with MRI. This showed that the breakthrough in traditional verbal ToM tasks at 4 years was related to cortical maturation of the Default Mode Network, also supporting ToM in adults, whereas infant ToM tasks were related to the maturation of distinct brain regions, which are part of the Salience network, supporting that infant ToM tasks rely on different processes than mature ToM. Based on the role of the Salience network in bottom-up attention processes, we proposed that infant ToM success may rely on social attention biases.

Grosse Wiesmann, C., Friederici, A. D., Singer, T., & Steinbeis, N. (2020). Proceedings of the National Academy of Sciences, 117(12), 6928-6935.

A new theory about infant ToM abilities
Based on the above findings, we proposed a new theory of infant ToM success. We proposed that others bias infants’ own representation of the world, allowing them to predict how others will act based on their own biased perspective, without the need to manage diverging perspectives. We reasoned that the development of a self-concept in the second year of life increases the salience of the own perspective compared to events attended together with others.

Grosse Wiesmann, C., & Southgate, V. (2021). The neural basis of mentalizing (pp. 49). Springer International Publishing.

Evidence for altercentric biases
We tested the above theory in a series of behavioral studies, revealing an altercentric bias in young infants’ object memory that receded in the second year of life. That is, 8-months-old infants misremembered an object where another agent had seen it last, although the infants themselves had subsequently seen the object move elsewhere. Similarly, infants searched in a box when someone else falsely believed an object to be in there, although the infants had seen that the object had been removed. This altercentric bias in infants’ object search decreased in the second year of life in relation with children’s self-concept development. These findings indicate that infants misremember objects where they have seen them together with others, providing a potential mechanism for understanding others and predicting their actions, without the need to represent different perspectives.

Manea, V., Kampis, D., Grosse Wiesmann, C., Revencu, B., & Southgate, V. (2023). Proceedings of the Royal Society B, 290(2000), 20230738.
Kampis, D., Grosse Wiesmann, C., & Southgate, V. (2021). Proceedings of the Annual Meeting of the Cognitive Science Society (Vol. 43).

Decrease of altercentric biases with emergence of the self-concept
To assess the development of the self-concept in toddlerhood, we developed a series of tasks tapping into self-other distinction and self-related biases in children’s choices and memory. We showed that, by 16 months, infants understand the self in relation to others. Around 2 years, children’s own choices begin to induce preferences (Grosse Wiesmann et al., 2022). Moreover, we show a shift from better memory for objects that are relevant to others towards better memory for self-relevant objects with the emergence of mirror self-recognition around 18 months of age (Grosse Wiesmann et al., in prep.).

Kampis, D.*, Grosse Wiesmann, C.*, Koop, S., & Southgate, V. (2022). Developmental science, 25(3), e13197. *contributed equally.
Grosse Wiesmann, C., Kampis, D., Poulsen, E., Schüler, C., Duplessy, H. L., & Southgate, V. (2022). Cognition, 223, 105039.
Grosse Wiesmann, C., Rothmaler, K., Hasan, E., Habdank, K., & Southgate, V. (in prep.)

Dissemination:
- Press releases
- Broad press coverage and interviews in newspapers and broadcasting (e.g. Mitteldeutscher Rundfunk, Science Daily, Austrian Press Agency)
- Blog article in Spektrum.de (https://scilogs.spektrum.de/thinky-brain/verstehen-kleinkinder-was-in-unserem-kopf-vorgeht/ )
- Conference presentations, keynotes, & symposia (e.g. at SfN 2018, BCCCD 2019-2023, CogSci 2020,2021, ICPS 2019,2023, ESPP 2021)
Taken together, the results of ToMSelfLink give an entirely new perspective on how infants understand others and perceive their environment guided by others. Two decades of ToM research in infancy have suggested that preverbal infants may have a ToM, creating a puzzle how they manage the executive demands of reasoning about different perspectives. ToMSelfLink shows that infant ToM success is related to different brain networks than mature verbal ToM. Based on this, we have proposed and found evidence that, instead of reasoning about others’ beliefs as distinct from their own, preverbal infants have a memory bias for information relevant to others. This allows infants to understand others and predict their actions, without the need to infer their distinct perspective. Thus, as opposed to classic developmental theories that have assumed that young children are egocentric, ToMSelfLink suggests that infants are in fact altercentric and view the world as seen by others.
ToMSelfLink shows that this early altercentrism decreases as the self-concept develops in the second year of life, giving rise to well-known self-related biases, such as a preference for one’s own choices thought to result from cognitive dissonance as well as better memory for self-relevant content referred to as self-reference effect. ToMSelfLink thus changes not only our understanding of early social cognitive development and ToM, but also gives insight into the development of classic phenomena of memory and social psychology.
We are currently investigating whether the different systems and neural networks found for reasoning about others in infancy and preschool-age persist in parallel until adulthood, and whether altercentrism may provide a fast and efficient route for understanding others also in adults. Furthermore, future research may test how the early developing versus later developing system and neural networks are modulated in clinical populations, such as Autism Spectrum Disorder. Understanding this, may inform early diagnosis and outline more targeted interventions, highlighting the potential translational impact of the project.
Two Systems for reasoning about others in the developing brain (Grosse Wiesmann et al., 2020, PNAS)