Extended Data Fig. 4: Fitting egocentric maps to empirical data, part 2: setup and behavioural measures.
a) To create a model egocentric map around the upper body, we created a default set of voxels on the surface of the hand, head, and trunk, which offered reward upon contact (coloured cubes). Experiment-dependent variations of these rewarded voxels are shown in b-e. For extended data fitting methodology, see Methods 'Empirical data fitting' and Supplementary Methods 3.4.1. b) To model arm-centred peripersonal neurons in macaques (Fig. 7a), we created two sets of voxels, each simulating one of the two arm positions during the experiment. c) In a subset of human experiments (I,j,l,m,n,o,p; Fig. 7e–h), the hand was held in front of the chest, instead of to the side. d) To model experiments with variable stimulus valence (n,o,p), we additionally optimised the negative reward offered by contact (Methods, 'Empirical data fitting' & Supplementary Methods 3.4.1). The optimised reward values implied by the stimuli of differing valence are shown in q. e) To model tool use (m; Fig.7h), we also rewarded contact with the tip of a tool. The two tool-related experiments used a stick and a rake, which we respectively modelled with 1 (green) or 5 (yellow) voxels. f-p) Empirical data (right in each panel) and model fits (left in each panel) from experiments in which behavioural peripersonal measures were collected. For data and fits of neural measures, see Fig. 7c–h. Colours indicate experimental conditions. Shaded surfaces on figurines show body parts included in the egocentric map. Error bars show SEM. For a detailed description of each fitted experiment, see Supplementary Methods 3.4.1. f) See Supplementary Methods 3.4.1.6 for details. g) See Supplementary Methods 3.4.1.6 for details. h) See Supplementary Methods 3.4.1.6 for details. i) See Supplementary Methods 3.4.1.6 for details. j) See Supplementary Methods 3.4.1.6 for details. k) See Supplementary Methods 3.4.1.6 for details. l) See Supplementary Methods 3.4.1.6 for details. m) See Supplementary Methods 3.4.1.7 for details. n) See Supplementary Methods 3.4.1.8 for details. o) See Supplementary Methods 3.4.1.9 for details. p) See Supplementary Methods 3.4.1.10 for details. q) Best-fitting negative reward magnitudes for the stimuli of differing valence from experiments displayed in n,o, and p.
