Periodic Reporting for period 1 - ITDA (An integrated theory of deciding and acting)
Reporting period: 2022-09-01 to 2025-02-28
Goal-directed behavior requires a translation of our choices into actions through muscle contractions. Research in cognitive psychology and neuroscience has focused on the decision-making process during the past fifty years, but the articulation between decision and motor systems remains poorly understood. Progressing on this issue is important for several reasons. From a decision neuroscience perspective, it is unclear whether the motor system simply executes our choices or actively contributes to deliberation. From a motor neuroscience perspective, understanding movements requires an understanding of neural inputs to muscles and upstream processes that determine them. Finally, several psychiatric and neurological disorders appear to affect both decision and motor systems , as suggested by apathy and impulse control disorders, psychomotor retardation symptoms, and paradoxical movements, among others. A precise understanding of these alterations and the development of efficient therapeutic strategies requires an integrated theory of decision and motor processes. The development of such a theory constitutes the overarching aim of the present research project.
We have used a so-called model-based cognitive neuroscience methodology to develop the theory. This methodology combines behavioral research (experimental tasks conducted in the laboratory, involving different decision situations at different time scales and different effectors to communicate choices), recordings of electrical activity from the brain and the muscles using electroencephalography and electromyography, and mathematical modeling of the empirical data. The latter is important, because it provides a formal framework for quantifying and rigorously analyzing decision and motor processes that are not directly available through observation. Ultimately, it will allow us to precisely identify the effects of various neuropsychiatric disorders through a reverse engineering technique: by fitting the model to patient data, we will be able to deduce the processing components that generated these outcomes.
Our main accomplishment so far is the development of a formal theory of decision and motor processes that provides a good quantitative account of behavioral and neuromuscular data in (i) decision tasks in which the choice must to be communicated as quickly and as accurately as possible (Dendauw et al., 2024, Psychological Review), and (ii) decision tasks that involve a delay between the commitment to a choice and the execution of that choice through actions (Achard et al., 2025, Journal of Experimental Psychology: General). The theory has been developped for the musculoskeletal motor system (that controls the movement of the limbs), and we are currently extending it to the oculomotor system (that controls the movement of the eyes).