title: Chromatic and Achromatic Spatial Resolution of Local Field Potentials in Awake Cortex.
abstract: Local field potentials (LFPs) have become an important measure of neuronal population activity in the brain and could provide robust signals to guide the implant of visual cortical prosthesis in the future. However, it remains unclear whether LFPs can detect weak cortical responses (e.g., cortical responses to equiluminant color) and whether they have enough visual spatial resolution to distinguish different chromatic and achromatic stimulus patterns. By recording from awake behaving macaques in primary visual cortex, here we demonstrate that LFPs respond robustly to pure chromatic stimuli and exhibit ∼2.5 times lower spatial resolution for chromatic than achromatic stimulus patterns, a value that resembles the ratio of achromatic/chromatic resolution measured with psychophysical experiments in humans. We also show that, although the spatial resolution of LFP decays with visual eccentricity as is also the case for single neurons, LFPs have higher spatial resolution and show weaker response suppression to low spatial frequencies than spiking multiunit activity. These results indicate that LFP recordings are an excellent approach to measure spatial resolution from local populations of neurons in visual cortex including those responsive to color.
authors.affiliation: Department of Biological Sciences and.
authors.forename: Michael
authors.initials: M
authors.lastname: Jansen
authors.affiliation: Department of Biological Sciences and.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Biological Sciences and Department of Biomedical Engineering, School of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Lashgari
authors.affiliation: Department of Biological Sciences and.
authors.forename: Jens
authors.initials: J
authors.lastname: Kremkow
authors.affiliation: Psychology, University of Connecticut, Storrs, CT, USA.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Bereshpolova
authors.affiliation: Department of Biological Sciences and Psychology, University of Connecticut, Storrs, CT, USA.
authors.forename: Harvey A
authors.initials: HA
authors.lastname: Swadlow
authors.affiliation: Graduate Center for Vision Research, SUNY College of Optometry, New York, NY, USA.
authors.forename: Qasim
authors.initials: Q
authors.lastname: Zaidi
authors.affiliation: Department of Biological Sciences and Psychology, University of Connecticut, Storrs, CT, USA.
authors.forename: Jose-Manuel
authors.initials: JM
authors.lastname: Alonso
mesh_terms: D000200:Action Potentials; D000818:Animals; D058256:Brain Waves; D003118:Color Perception / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology
keywords: LFP; area V1; color; receptive field; striate cortex