Are temporal response features prepared in fixed order? Inferences from movement-related potentials

Area of Science:

• Cognitive Neuroscience
• Motor Control
• Psychology

Background:

• The generalized motor program (GMP) theory posits that motor preparation involves a fixed sequence for temporal response features.
• Investigating the order of motor preparation is crucial for understanding motor control and cognitive processes.

Purpose of the Study:

• To examine whether the preparation of temporal response features adheres to a fixed order, as suggested by the GMP theory.
• To investigate the impact of advance information on motor preparation and its neural correlates.

Main Methods:

• A response precuing task was employed, manipulating relative timing and overall duration of sequential key presses.
• Participants received precues with varying levels of information (none, partial, or full) about the upcoming response.
• Electrophysiological measures, including contingent negative variation (CNV) and lateralized readiness potential (LRP), were recorded.

Main Results:

• Reaction times decreased as the amount of advance information increased, indicating reduced response alternatives and modified preparatory processes.
• Contingent negative variation (CNV) showed increased amplitude over left motor regions with more advance information.
• The lateralized readiness potential (LRP) indicated hand-specific activation only in the full precue condition.

Conclusions:

• The findings contradict the GMP assumption of a fixed preparation order for invariant and variable response features.
• Motor preparation appears to be more flexible, with advance information influencing preparatory processes and their neural correlates.
• This suggests that temporal response features are not necessarily prepared in a predetermined sequence.