title: The neuroimaging signal is a linear sum of neurally distinct stimulus- and task-related components.
abstract: Neuroimaging (for example, functional magnetic resonance imaging) signals are taken as a uniform proxy for local neural activity. By simultaneously recording electrode and neuroimaging (intrinsic optical imaging) signals in alert, task-engaged macaque visual cortex, we recently observed a large anticipatory trial-related neuroimaging signal that was poorly related to local spiking or field potentials. We used these same techniques to study the interactions of this trial-related signal with stimulus-evoked responses over the full range of stimulus intensities, including total darkness. We found that the two signals could be separated, and added linearly over this full range. The stimulus-evoked component was related linearly to local spiking and, consequently, could be used to obtain precise and reliable estimates of local neural activity. The trial-related signal likely has a distinct neural mechanism, however, and failure to account for it properly could lead to substantial errors when estimating local neural spiking from the neuroimaging signal.
authors: Department of Neuroscience, Columbia University, New York, New York, USA.
authors: Mariana M B
authors: MM
authors: Cardoso
authors: Yevgeniy B
authors: YB
authors: Sirotin
authors: Bruss
authors: B
authors: Lima
authors: Elena
authors: E
authors: Glushenkova
authors: Aniruddha
authors: A
authors: Das
mesh_terms: D000465:Algorithms; D000818:Animals; D002560:Cerebrovascular Circulation / Q000502:physiology; D003216:Conditioning, Operant; D003463:Cues; D003624:Darkness; D004567:Electrodes, Implanted; D055724:Electrophysiological Phenomena; D005071:Evoked Potentials / Q000502:physiology; D005403:Fixation, Ocular / Q000502:physiology; D006439:Hemodynamics; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008253:Macaca mulatta; D009424:Nervous System Physiological Phenomena; D059906:Neuroimaging / Q000379:methods*; D009482:Neurophysiology; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology