Figure 1. | Perceptual decisions are biased by the cost to act
Perceptual decisions are biased by the cost to act
University College London, United Kingdom; Center for Information and Neural Networks (CiNet), National Institute of Communications and Technology, Japan; Western University, Canada
Download figureOpen in new tabFigure 1. Setup of the experiment and the shift of PSE induced by the motor cost.
(A) Participants made 15 cm reaching movement to the target with their hand (left or right), in response to the perceived direction (left or right) of the random-dot motion. (B) In all the experiments, the baseline phase and the test phase was interleaved by the induction phase, in which the resistance for one of the manipulandum movement gradually increased. (C) In Experiment 3, the baseline and the test phase included both manual and vocal motion discrimination, each being serially presented within a 10 trial block. (D) Fitted psychometric function to the probability of a response towards the right in the baseline (blue) and the test (red) phase of a representative participant (Experiment 1). Negative motion coherence value indicates the leftward motion (with manual resistance), and positive towards the right (without manual resistance). (E) Shift of PSE from the baseline in Experiments 1, 2, 3 and 4. Negative value indicates the PSE shift towards the motion direction with resistance (i.e. decreased judgements towards the motion direction having resistance in their manual response). Error bars indicate standard error of mean across participants. Data for Figure 1E is available as Figure 1—source data 1. *p<0.05, **p<0.01.
Download figureOpen in new tabFigure 1—figure supplement 1. Example of the peak resistive force increase profile in the study.
The presented data is force data from Experiment 1, averaged across trials and participants in each session. Here, each session contains 66 trials (33 trials for each left and right) of reaching movements. Since the resistive force is provided in a velocity-dependent manner, the variance is reflecting the variability of the movement velocity across participants.