Dissociating explicit timing from temporal expectation with fMRI

• Published in: Current opinion in neurobiology Vol. 18; no. 2; pp. 137 - 144
• Main Authors: Coull, JT, Nobre, AC
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2008; Elsevier
• Subjects: Basal Ganglia - anatomy & histology; Basal Ganglia - physiology; Cerebellum - anatomy & histology; Cerebellum - physiology; Functional Laterality - physiology; Humans; Life Sciences; Magnetic Resonance Imaging - methods; Memory - physiology; Motor Cortex - anatomy & histology; Motor Cortex - physiology; Neural Pathways - anatomy & histology; Neural Pathways - physiology; Neurology; Neurons and Cognition; Psychiatry; Reaction Time - physiology; Time Perception - physiology
• ISSN: 0959-4388; 1873-6882
• DOI: 10.1016/j.conb.2008.07.011

Explicit timing is engaged whenever subjects make a deliberate estimate of discrete duration in order to compare it with a previously memorised standard. Conversely, implicit timing is engaged, even without a specific instruction to time, whenever sensorimotor information is temporally structured and can be used to predict the duration of future events. Both emergent timing (motor) and temporal expectation (perceptual) are forms of implicit timing. Recent fMRI studies demonstrate discrete neural substrates for explicit and implicit timing. Specifically, basal ganglia are activated almost invariably by explicit timing, with co-activation of prefrontal, premotor and cerebellar areas being more context-dependent. Conversely, implicit perceptual timing (or “temporal expectation”) recruits cortical action circuits, comprising inferior parietal and premotor areas, highlighting its role in the optimisation of prospective behaviour.