Related Experiment Video
Updated: Jan 6, 2026
07:11
Author Spotlight: Insights into Visual Cortex Research Through Wide-View fMRI Mapping
Published on: December 8, 2023
2.3K
Sensory stimulation shifts visual cortex from synchronous to asynchronous states
Andrew Y Y Tan1, Yuzhi Chen2, Benjamin Scholl1
11] Center for Perceptual Systems, University of Texas, Austin, Texas 78712, USA [2] Department of Neuroscience, College of Natural Sciences, University of Texas, Austin, Texas 78712, USA [3].
Nature
|April 4, 2014
Summary
Mammalian cerebral cortex activity is highly variable. This study reveals that during fixation, neural activity is synchronous, shifting to an asynchronous state with visual stimulation, challenging previous models.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Systems Neuroscience
Background:
- Neural responses in the mammalian cerebral cortex exhibit high variability during both spontaneous activity and sensory stimulation.
- Two main hypotheses explain this variability: an asynchronous high-conductance state or infrequent correlated input events causing large membrane potential fluctuations.
- Distinguishing between these states is crucial for understanding cortical computation.
Purpose of the Study:
- To investigate the state of the primary visual cortex (V1) in behaving monkeys during spontaneous and stimulated activity.
- To differentiate between the asynchronous high-conductance state and correlated input event hypotheses for neural variability.
- To determine how sensory stimulation affects cortical network states.
Main Methods:
- Developed a novel technique for whole-cell membrane potential (Vm) measurements in the cortex of behaving monkeys.
- Focused recordings on the primary visual cortex (V1) during a visual fixation task.
- Correlated Vm fluctuations with simultaneously recorded local field potential (LFP) to assess network activity.
Main Results:
- Contrary to the asynchronous state prediction, mean Vm during fixation was significantly below threshold, with spiking driven by large, infrequent fluctuations.
- Vm distributions were skewed, consistent with correlated input events rather than Gaussian input.
- Visual stimulation shifted Vm towards threshold, made fluctuations more Gaussian, and disrupted neural-network correlations, resembling an asynchronous state.
Conclusions:
- The mammalian cerebral cortex operates in a synchronous state during spontaneous activity, characterized by infrequent correlated inputs.
- Sensory drive can transition cortical circuitry from a synchronous to an asynchronous state.
- These findings challenge the prevailing view of a constantly asynchronous cortical state in alert animals.
Related Concept Videos
01:14Motor and Sensory Areas of the Cortex
6.7K
The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex....
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex....
6.7K
01:24Vision
59.2K
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
59.2K
01:20Parallel Processing
593
The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and...
593
01:28Major Somatic Sensory Pathways
2.3K
Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the...
2.3K
01:24Somatosensory, Motor, and Association Cortex
2.1K
The somatosensory cortex in the parietal lobes is crucial for interpreting sensory data such as touch, temperature, and proprioception. The somatosensory cortex, situated in the parietal lobes, plays a vital role in interpreting sensory information like touch, temperature, and proprioception—awareness of body position. This specialized brain region features an organized structure wherein neurons at the top primarily process sensations originating from the lower body. In contrast, those at...
2.1K