Analysis of hand kinematics reveals inter-individual differences in intertemporal decision dynamics.
During intertemporal decisions, the preference for smaller, sooner reward over larger-delayed rewards (temporal discounting, TD) exhibits substantial inter-subject variability; however, it is currently unclear what are the mechanisms underlying this apparently idiosyncratic behavior. To answer this question, here we recorded and analyzed mouse movement kinematics during intertemporal choices in a large sample of participants (N = 86). Results revealed a specific pattern of decision dynamics associated with the selection of "immediate" versus "delayed" response alternatives, which well discriminated between a "discounter" versus a "farsighted" behavior-thus representing a reliable behavioral marker of TD preferences. By fitting the Drift Diffusion Model to the data, we showed that differences between discounter and farsighted subjects could be explained in terms of different model parameterizations, corresponding to the use of different choice mechanisms in the two groups. While farsighted subjects were biased toward the "delayed" option, discounter subjects were not correspondingly biased toward the "immediate" option. Rather, as shown by the dynamics of evidence accumulation over time, their behavior was characterized by high choice uncertainty.
Department of Neuroscience, Imaging and Clinical Sciences, G. D'Annunzio University, Via dei Vestini 33, 66013, Chieti Scalo, Italy. cinzia.calluso@unich.it.|Institute for Advanced Biomedical Technologies, G. D'Annunzio University, Via dei Vestini 33, 66013, Chieti Scalo, Italy. cinzia.calluso@unich.it.
Cinzia
C
Calluso
Department of Neuroscience, Imaging and Clinical Sciences, G. D'Annunzio University, Via dei Vestini 33, 66013, Chieti Scalo, Italy.|Institute for Advanced Biomedical Technologies, G. D'Annunzio University, Via dei Vestini 33, 66013, Chieti Scalo, Italy.
Giorgia
G
Committeri
Institute of Cognitive Sciences and Technologies, National Research Council, Via S. Martino della Battaglia 44, 00185, Rome, Italy.
Giovanni
G
Pezzulo
Department of Engineering Mathematics, University of Bristol, Bristol, UK.|Bristol Robotics Laboratory (BRL), University of Bristol and University of the West of England, Bristol, UK.
Nathan
N
Lepora
Department of Neuroscience, Imaging and Clinical Sciences, G. D'Annunzio University, Via dei Vestini 33, 66013, Chieti Scalo, Italy.|Institute for Advanced Biomedical Technologies, G. D'Annunzio University, Via dei Vestini 33, 66013, Chieti Scalo, Italy.
Annalisa
A
Tosoni
D000328:Adult; D001696:Biomechanical Phenomena; D002755:Choice Behavior / Q000502:physiology*; D065786:Delay Discounting / Q000502:physiology*; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D011597:Psychomotor Performance / Q000502:physiology*; D055815:Young Adult
Choice behavior; Decision making; Mathematical models