Decision making and action implementation: evidence for an early visually triggered motor activation specific to...

Area of Science:

• Cognitive Neuroscience
• Motor Control
• Decision Making

Background:

• Decision-making models often involve accumulating sensory evidence to reach a threshold.
• Sequential-sampling models explain evidence accumulation and its link to action implementation.
• The precise timing and specificity of action implementation relative to decision-making remain under investigation.

Purpose of the Study:

• To test a model predicting early action implementation specific to potential actions.
• To investigate the dynamics of action implementation in response to visual stimuli.
• To explore the relationship between decision processes and motor cortex activation.

Main Methods:

• Utilized transcranial magnetic stimulation (TMS) of the motor cortex.
• Employed single- and paired-pulse TMS with a 3-ms interstimulus interval.
• Assessed action implementation dynamics in go/no-go and between-hand choice tasks.

Main Results:

• Motor evoked potential amplitude increased prior to action implementation.
• This increase occurred regardless of the visual stimulus but was specific to the hand potentially involved in the action.
• Findings suggest early motor activation is triggered by visual stimuli for potential actions.

Conclusions:

• Visual stimuli can initiate early motor activation linked to potential actions.
• Results support race-like models where decision-making and action implementation are continuously linked.
• The motor cortex shows anticipatory activation specific to potential action plans.