Poster No:
939
Submission Type:
Abstract Submission
Authors:
Niloofar Gharesi1, John Kalaska2, Sylvain Baillet3
Institutions:
1McGill University, Montréal, Quebec, 2Université de Montréal, Montreal, Quebec, 3Montreal Neurological Institute, Montreal, Quebec
First Author:
Co-Author(s):
Introduction:
Daily decisions often involve conflicting sensory inputs, requiring the choice of one action from multiple alternatives. The dorsal premotor cortex (PMd) plays a crucial role in guiding voluntary arm movements, serving as a convergence point for sensory instructional and action-related information. Neural activity in the PMd is strongly modulated by sensory inputs that support different motor responses and in constructing representations of potential arm movement choices1. Moreover, PMd activity exhibits correlations with high-level abstract concepts related to actions even before these actions are fully specified, such as the overarching goal of future actions or a visuomotor task rule2,3. It can also express learned stimulus–response associations during mental rehearsal without the occurrence of actual movements4,5. Kalaska and colleagues conducted several studies on the involvement of PMd in reaching decisions in tasks requiring subjects to discern the dominant color of a multi-colored checkerboard Decision Cue (DC) to choose between two color-coded targets. The strength of DC evidence was manipulated by varying the proportion of small squares of the two choice colors. In the Targets First (TF) task, the two-colored targets appeared first in each trial, followed by the DC after a delay. The TF task revealed that PMd neural activity in monkeys correlated with strength of DC evidence and the direction of the selected target but was poorly modulated by the color of the evidence itself6. However, functional interpretation of the observed PMd neural responses in this task was confounded by the fact that the onset of the DC could simultaneously initiate both perceptual deliberation and action selection processes.
The Checkerboard First (CF) task addresses this limitation. In the CF task, the DC appears before the two-colored targets, enabling participants to make a categorical perceptual decision about the dominant DC color independently of how the decision would be reported7. In monkeys, PMd is active during action selection but does not participate in the perceptual components of the decision-making process8. PMd units exhibit strongly-modulated activity only when complete information about the stimulus–response associations determining action choices is accessible. PMd activity predominantly reflects the chosen reach direction, the strength of evidence supporting those actions, and the temporal dynamics of the action decisions, but not the dominant color of the DC evidence.
Methods:
We employed similar tasks while human subjects underwent magnetoencephalography (MEG) recordings. Subjects performed a TFD and CFD task with an enforced delay interval after each of the two instructional cues appeared. The number of Cyan or Orange squares supporting the correct color/target choice was kept constant in each DC, and we varied the amount of conflicting evidence for the wrong choice. Specifically, the number of DC squares of each color in a trial could be 64/1, 64/32, 64/48, 64/56, 64/60, or 64/62 of either C/O or O/C, resulting in a set of 12 distinct DCs. A differential auditory tone at the end of each trial provided the subjects with knowledge of results (KR; correct or incorrect target choice).
Results:
We found the classic pattern of progressive beta-band power suppression over PMd during each instructed-delay epoch of the trial, followed by a rebound after chosen movement onset. The strength of suppression was strongest during second delay epoch of both the TFD and CFD tasks, when full information about response choices was available. The rate of beta suppression during that second delay epoch was also modulated by the strength of DC evidence in both tasks, but not by the dominant color.
Conclusions:
Importantly, the auditory KR tones evoked a beta suppression/rebound that was modulated by the DC evidence strength on which the subjects made their decision in each trial, which is a potential neural correlate of a response prediction error signal in PMd.
Higher Cognitive Functions:
Executive Function, Cognitive Control and Decision Making 1
Higher Cognitive Functions Other
Modeling and Analysis Methods:
EEG/MEG Modeling and Analysis 2
Motor Behavior:
Motor Planning and Execution
Novel Imaging Acquisition Methods:
MEG
Keywords:
Cognition
Cortex
MEG
Motor
Other - color/location conjunction, beta power, ambiguous decisions
1|2Indicates the priority used for review
Provide references using author date format
[1] Cisek, P., & Kalaska, J. F. (2005). Neural correlates of reaching decisions in dorsal premotor cortex: specification of multiple direction choices and final selection of action. Neuron, 45(5), 801-814.
[2] Buch, E. R., Brasted, P. J., & Wise, S. P. (2006). Comparison of population activity in the dorsal premotor cortex and putamen during the learning of arbitrary visuomotor mappings. Experimental brain research, 169, 69-84.
[3] Wallis, J. D., & Miller, E. K. (2003). From rule to response: neuronal processes in the premotor and prefrontal cortex. Journal of neurophysiology, 90(3), 1790-1806.
[4] Cisek, P., & Kalaska, J. F. (2004). Neural correlates of mental rehearsal in dorsal premotor cortex. Nature, 431(7011), 993-996.
[5] Gharesi, N., Luneau, L., Kalaska, J. F., & Baillet, S. (2023). Evaluation of abstract rule-based associations in the human premotor cortex during passive observation. bioRxiv.
[6] Coallier, É., Michelet, T., & Kalaska, J. F. (2015). Dorsal premotor cortex: neural correlates of reach target decisions based on a color-location matching rule and conflicting sensory evidence. Journal of neurophysiology, 113(10), 3543-3573.
[7] Coallier, É., & Kalaska, J. F. (2014). Reach target selection in humans using ambiguous decision cues containing variable amounts of conflicting sensory evidence supporting each target choice. Journal of neurophysiology, 112(11), 2916-2938.
[8] Wang, M., Montanède, C., Chandrasekaran, C., Peixoto, D., Shenoy, K. V., & Kalaska, J. F. (2019). Macaque dorsal premotor cortex exhibits decision-related activity only when specific stimulus–response associations are known. Nature communications, 10(1), 1793.