John H. Reynolds
Systems Neurobiology Laboratory
The long-range goal of our laboratory is to understand the neural mechanisms of selective visual attention at the level of the individual neuron and the cortical circuit, and to relate these to perception and conscious awareness. We take as our starting point the observation that the brain is limited in the amount of visual information it can process at any moment in time. For instance, when people are asked to identify the objects in a briefly presented scene, they become less accurate as the number of objects increases. This inability to process more than a few objects at a time reflects the limited capacity of some stage (or stages) of sensory processing, decision-making, or behavioral control. Somewhere between stimulating the retina and generating a behavioral response, objects compete with one another to pass through this computational bottleneck. We seek to understand this selection process using a combination of visual psychophysics, neurophysiology, and computational neural modeling.
"The long-range goal of our laboratory is twofold–to understand the fundamental nature of the computations that are carried out by the neocortex and to understand how and why these computations fail in brain disease."
Evolution has endowed our brains with a system of neural mechanisms whose function is to choose which information will be selected to guide our behavioral decisions. When this system fails, as in disorders such as schizophrenia, Alzheimer's disease and attention deficit hyperactivity disorder (ADHD), the effects on the quality of life can be devastating. Reynolds's team is working to decipher the neural mechanisms of attention, which are key to understanding and treating brain diseases in which the attention system fails.
At any point in time, our brains are able to process only a small fraction of the totality of information available in the sensory environment. Even if we wanted to pay attention to many things at once, there are limits on how many stimuli we can juggle simultaneously. What's more, only a small fraction of available sensory information is needed to make effective behavioral decisions, and the information that is needed changes from moment to moment, depending on our needs and the risks and possibilities presented by our ever-changing environment. The attentional system thus plays the critical role of "perceptual gatekeeper," selecting task relevant information for processing while keeping distracting information from entering conscious awareness.
Reynolds's team has found that when attention is directed toward a stimulus, attentional control centers of the brain send signals that tell the perceptual systems to favor certain circuits over others. As a result, neurons that convey information about an attended stimulus are more active, while neurons that would otherwise convey distracting information are suppressed. They have also recently discovered that attention reduces the variability or "noise" in neuronal signals, improving the quality of information about the visual stimuli to which we attend.
They are now conducting experiments to understand the neural mechanisms underlying these attention-dependent changes in neural signaling. To do this, they use a range of techniques, including neurophysiology, neuroanatomy, computational modeling, visual psychophysics and cutting-edge optogenetic techniques that enable the use of viruses to change the DNA of neurons so that they create proteins that act as light sensors. This enables them to use light to alter the activity of specific types of neurons and understand their role in perception, attention and behavior.
Left to right:
Jude Mitchell, Emily Anderson, John Curtis, Hendrikje Nienborg, Anita Disney, Catherine Williams, Jonathon Nassi, John Reynolds
Sundberg KA, Mitchell JF, Gawne TJ, and Reynolds JH (2012) Attention Influences Single Unit and Local Field Potential Response Latencies in Visual Cortical Area V4, The Journal of Neurosciences, 32(45):16040-16050. Download the article.
Fallah M, Reynolds JH (2012) Contrast Dependence of Smooth Pursuit Eye Movements following a Saccade to Superimposed Targets. PLoS ONE 7(5): e37888. View the article.
Ciaramitaro VM, Mitchell JF, Stoner GR, Reynolds JH, and Boynton GM (2011) Object-based attention to one of two superimposed surfaces alters responses in human early visual cortex, Journal of Neurophysiology, 105:1258-1265, 2011. Download the article.
Anderson EB, Mitchell JF, Reynolds JH (2011) Attentional Modulation of Firing Rate Varies with Burstiness across Putative Pyramidal Neurons in Macaque Visual Area V4, The Journal of Neuroscience, 31(30):10983-10992. Download the article.
Mitchell JF, Sundberg KA, and Reynolds JH (2009) Spatial Attention Decorrelates Intrinsic Activity Fluctuations in Macaque Area V4, Neuron, 63:879-888. Download the article. | Download the supplemental material.
Sundberg KA, Mitchell JF, and Reynolds JH (2009) Spatial Attention Modulates Center-Surround Interactions in Macaque Visual Area V4, Neuron, 61:952-963. Download the article. | Download the supplemental material.
Berdyyeva TK, Reynolds JH (2009) The Dawning of Primate Optogenetics, Neuron, 62:159-160. Download the preview.
Reynolds JH (2008) Three Hundred Million Years of Attentional Selection, Neuron, 60:528-529. Download the preview.
Reynolds JH (2008) Mapping the microcircuitry of attention, Nature Neuroscience, 11:861-862. Download the article.
Mitchell JF, Sundberg KA, Reynolds JH (2007) Differential Attention-Dependent Response Modulation across Cell Classes in Macaque Visual Area V4, Neuron, 55(1):131-41. Download the preview | Download the article. | Download the supplemental material.
Bodelon C, Fallah M, Reynolds JH. (2007) Temporal resolution for the perception of features and conjunctions, The Journal of Neuroscience, 27(4):725-30. Download the article.
Fallah M, Stoner GR, Reynolds JH (2007) Stimulus-specific competitive selection in macaque extrastriate visual area V4, Proceedings of the National Academy of Sciences, 104(10): 4165-4169. Download the article. | Download supplemental material.
Stoner GR, Mitchell JF, Fallah M, Reynolds JH. (2005) Interacting competitive selection in attention and binocular rivalry, Prog Brain Res, 149:227-34. Download the article.
Khoe W, Mitchell JF, Reynolds JH, Hillyard SA. (2005) Exogenous attentional selection of transparent superimposed surfaces modulates early event-related potentials, Vision Res, 45(24):3004-14. Download the article.
Mitchell JF, Stoner GR, and Reynolds JH (2004) Object-Based Attention Determines Dominance in Binocular Rivalry, Nature, 429:410-413. Download the article.
Reynolds JH and Chelazzi L (2004) Attentional Modulation of Visual Processing, Annual Review of Neuroscience, 27:611-647. Download the article.
Reynolds JH and Fallah M (2004) The role of competitive circuits in extrastriate cortex in selecting spatially superimposed stimuli. Functional Neuroimaging of Visual Cognition Attention and Performance XX, Kanwisher N and Duncan J, Eds. Oxford University Press. 363-380.
Reynolds JH and Desimone R (2003) Interacting Roles of Attention and Visual Salience in V4, Neuron, 37(5):853-63. Download the article.
Mitchell JF, Stoner GR, Fallah M, and Reynolds J.H. (2003) Attentional selection of superimposed surfaces cannot be explained by modulation of the gain of color channels, Vision Research, 43(12):1323-8. Download the article.
Reynolds JH, Alborzian S, and Stoner GR (2003) Exogenously cued attention triggers competitive selection of surfaces, Vision Research, 43(1):59-66. Download the article.
Reynolds JH, Gottlieb JP, and Kastner S (2002) Attention, Fundamental Neuroscience Zigmond, Bloom, Landis, Roberts and Squire (Eds.), Academic Press.
Fallah M and Reynolds JH (2001) Attention! V1 neurons lining up for inspection, Neuron, 2001 31(5):674-5.
Fries P, Reynolds JH, Rorie AE, and Desimone R (2001) Modulation of Oscillatory Neuronal Synchronization by Selective Visual Attention, Science, 291: 1560-1563. Download the article.
Reynolds JH, Pasternak T, and Desimone R (2000) Attention Increases Sensitivity of V4 Neurons, Neuron, 26:703-714. Download the article.
Reynolds JH, and Desimone R (1999) The Role of Neural Mechanisms of Attention in Solving the Binding Problem, Neuron, 24:19-29. Download the article.
Reynolds JH, Chelazzi L, and Desimone R (1999) Competitive Mechanisms Subserve Attention in Macaque Areas V2 and V4, The Journal of Neuroscience, 19:1736-1753. Download the article.
Salk News Releases
Salk Institute promotes three top scientists
April 12, 2013
Gatsby Charitable Foundation awards $4 million to Salk-UC San Diego consortium to study brain circuitry
March 22, 2010
Rising above the din:
Attention makes sensory signals stand out amidst the background noise in the brain
September 23, 2009
Visual attention: how the brain makes the most of the visible world
March 25, 2009
From the corner of the eye: Paying attention to attention
July 5, 2007
The time it takes to reassemble the world
January 24, 2007
We live in the past and our brain makes up for it
February 1, 2006
Awards and Honors
- Sloan Research Fellowship 2002 - 2004
- McKnight Scholar Award 2001 - 2003
- Frederick B. Rentschler Developmental Chair 2001 - 2002