What are the fundamental cognitive dimensions and mechanisms which underlie the representations of actions in the brain?

Lead Research Organisation: University of York
Department Name: Psychology

Abstract

Successful social interactions require humans to accurately perceive the behaviour and actions of other individuals. Observing actions and behaviour provides a way for us to understand the intentions and minds of others, which has important implications for the way we interact. In recent years, a network of brain areas dedicated to the processing of action information has been uncovered. Despite this, however, it is still unknown what organising principles underlie our representation of the actions of other individuals. This project will address this problem by determining the psychological and neural 'space' in which actions are represented, and evaluating the dimensionality and shape of 'action-space'. The project will compile a comprehensive database of actions, generate a new large data-set of action evaluations, interrogate this new data set using novel experimental methodology and advanced quantitative statistics, and employ these findings to interrogate already existing large neural data-sets.

Prior research has indicated that we have multiple different maps and models of external stimuli, where their characteristics are represented in different dimensional spaces. For example, face evaluation occurs along either 2 (Oosterhof & Todorov, 2008) or 3 (Sutherland et al. 2013) important dimensions. However, there is currently much debate as to whether faces are represented with respect to a theoretical average face (norm-based coding), or whether faces are represented as example faces across face space (exemplar based coding). Action information can be more important for social decision making than face information (Aviezer et al. 2014), however, we don't know the organising principals of how actions are represented with respect to each other. Understanding this has important implications for understanding how we see, represent, remember, and make social judgements based on the actions of other individuals.

Initially, I will collate action videos from a number of large action databases to generate a broad stimulus set of approximately 500 naturalistic actions that vary as widely as possible. I will then record multiple participants' unconstrained descriptions of these actions, for each action (Expt. 1; Year 1 Term 1). The data from this experiment will provide common action descriptors on which a separate group of participants will provide ratings of the 500 actions (Expt. 2; Y1T2). An additional experiment will ask participants to provide similarity ratings between the 500 actions (Expt. 3; Y1T2). These experiments will generate a very large data-set that can be interrogated using advanced quantitative statistical techniques (multidimensional scaling; principal components analysis) to determine the dimensions on which humans evaluate naturally occurring actions. The multidimensional action space will be validated by testing with a novel set of 500 different social action videos (Expt. 4; Y1T3). Using adaptation procedures, the project will then evaluate the 'shape' of action-space in order to determine whether we represent actions on a norm or exemplar based code (Expt. 5+; Year 2).

Later in the project (Year 3), based upon the multidimensional framework established earlier, it will be possible to probe existing databases to determine the neural basis underlying how we make sense of social actions. Databases interrogated will include: 1. A large data-set of single neuron data of cells that respond selectively to complex social actions. 2. Structural brain data at the York Centre for Neuroimaging. This will for the first time tell us how the different dimensions on which human action are evaluated is coded at the single cell level, and in different regions of the cortex. In addition, I will use fMR adaptation techniques during neuroimaging to determine the neural basis of how we evaluate social actions.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
ES/P000746/1 01/10/2017 30/09/2027
1944008 Studentship ES/P000746/1 01/10/2017 31/03/2023 Claire Reading