Continuous Reaching Reveals Real Time Decision Dynamics Under Sensory Uncertainty

• Desiree Binns, Biomedical Engineering, University of Delaware

• Joshua Cashaback, Biomedical Engineering, University of Delaware
• Truc Ngo, Biomedical Engineering, University of Delaware

From navigating a crowded hallway to skiing down a treacherous slope, we are constantly using sensory information to make decisions and rapidly move. Experimentally, studies have manipulated sensory information to modulate deliberation behaviour throughout the decision-making process. Studies in non-human primates suggest that the motor control and decision-making neural circuitry continuously interacts. Recent work from our lab in human behaviour showed that reaching movements reflect the ongoing deliberation process—prior to a decision  Here, we further analyze reaching movements when we temporally manipulate sensory information available for deliberation. Participants will perform continuous reaching movements to two potential targets. Targets will individually appear into the targets, and participants indicated the target expected to finish with the most tokens. We manipulated the level of difficulty by changing the probability of which target will receive the most sensory information per reach. Additionally, we used bias token patterns to further modulate their deliberation. In the bias token patterns, the first three tokens moved into the left target or right target, the next three tokens moved into the opposite target, then the remaining tokens moved with 80% probability to the left or right target. We recorded their decision times and hand kinematics while reaching. Further assessing behavioural metrics modulated by sensory information during decision-making tasks may offer further insights into the deliberation process and its influences on movement.