Neural Control of Voluntary Movement Initiation

• Published in: Science (American Association for the Advancement of Science) Vol. 274; no. 5286; pp. 427 - 430
• Main Authors: Hanes, Doug P., Schall, Jeffrey D.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 18.10.1996; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Action Potentials; Anatomy; Animals; Biological and medical sciences; Brain; Cell growth; Cell motility; Computer Simulation; Eye Movements; Eyes; Frontal Lobe - physiology; Fundamental and applied biological sciences. Psychology; Least Squares Statistics; Linear Models; Linear regression; Macaca mulatta; Mathematical models; Modeling; Models, Neurological; Monkeys & apes; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Nervous system; Neurons; Neurons - physiology; Patch-Clamp Techniques; Physiological aspects; Propagation delay; Psychomotor Performance; Psychophysiology; Reaction Time; Reaction time (Psychology); Reaction Time - physiology; Regression (Statistics); Saccades; Saccades - physiology; Senses; Stochastic Processes; Synaptic Transmission; Threshing; Variable interest rates; Vertebrates: nervous system and sense organs; Motor pathway; Variability; Central nervous system; Discharge pattern; Monkey; Electrophysiology; Stochastic process; Motor control; Vertebrata; Mammalia; Motor cortex; Body movement; Primates; Reaction time; Brain (vertebrata)
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.274.5286.427

When humans respond to sensory stimulation, their reaction times tend to be long and variable relative to neural transduction and transmission times. The neural processes responsible for the duration and variability of reaction times are not understood. Single-cell recordings in a motor area of the cerebral cortex in behaving rhesus monkeys (Macaca mulatta) were used to evaluate two alternative mathematical models of the processes that underlie reaction times. Movements were initiated if and only if the neural activity reached a specific and constant threshold activation level. Stochastic variability in the rate at which neural activity grew toward that threshold resulted in the distribution of reaction times. This finding elucidates a specific link between motor behavior and activation of neurons in the cerebral cortex.