Dissociating explicit timing from temporal expectation with fMRI.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Human Motor Control

Background:

• Explicit timing involves deliberate duration estimation against a memorized standard.
• Implicit timing operates without explicit instruction, utilizing temporally structured sensorimotor information for prediction.
• Both motor (emergent timing) and perceptual (temporal expectation) processes are forms of implicit timing.

Purpose of the Study:

• To investigate the distinct neural substrates underlying explicit and implicit timing mechanisms.
• To differentiate the brain regions activated during deliberate duration estimation versus predictive temporal processing.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to observe brain activity.
• Participants' neural responses were analyzed during tasks requiring explicit timing and implicit temporal prediction.

Main Results:

• Explicit timing consistently activates the basal ganglia, with variable involvement of prefrontal, premotor, and cerebellar areas.
• Implicit perceptual timing (temporal expectation) primarily recruits inferior parietal and premotor cortical action circuits.

Conclusions:

• Distinct neural pathways support explicit and implicit timing.
• Implicit timing's engagement of cortical action circuits underscores its role in optimizing prospective, behavior-driven predictions.