The Mazer lab studies the role of extrastriate visual cortex in natural, visually guide behavior. We are interested in how cortical microcircuits support complex behavior. Current work in the lab focuses on three issues: (1) Characterizing neuronal responses to spectrally complex natural scene stimuli. This work uses modern linear and non-linear system identification methods to estimate the receptive field properties of visual neurons based on neuronal responses to natural visual stimuli. (2) Identifying the sources and circuits underlying top-down modulation of visual selectivity using neurophysiological methods.
We use visual search tasks in conjunction with single neuron recordings to investigate how attention and memory interact with visual processing during complex behavior to facilitate target detection. (3) Exploring interactions between visual processing and oculomotor behavior. These studies seek to clarify the relationship between spatial attention and the oculomotor planning processes by studying how saccadic eye movements affect the locus of spatial attention.
Extensive Research DescriptionNeuroscientists have identified more than 30 distinct cortical and sub-cortical areas in the primate brain that contribute to visual processing. However, we really only understand the specific contributions a small number of the areas make to visual perception.
In my laboratory we use a combination of neurophysiological, psychophysical, and computational methods to study the contributions of occipital and parietal cortex to visual perception and action. We use nonlinear system identification techniques to analyze both single neuron responses in extrastriate cortex and psychophysical performance data from subjects performing attentionally demanding visual search tasks. These data are used to construct visual selectivity profiles for both single neurons and individual subjects.
By using similar methods to study both single neurons and perception we can accurately estimate the contributions of single neurons to perception and action. The primary focus of this research is characterizing the effects of top-down modulatory signals on visual perception and to determine how the visual system influences the oculomotor system to guide eye movements during natural visual exploration of the world around us.
- Efficient coding of visual stimuli in early visual cortex.
- Non-linear processing of complex natural stimuli in extrastriate cortex.
- Attentional modulation of neural selectivity during visual search.
- Visual and attentional stability during natural vision.
- Sachdev R.N., Krause M.R., Mazer J.A., Surround suppression and sparse coding in visual and barrel cortices. Front Neural Circuits. 2012;6:43.
- Golomb, J. D., Marino, A. C., Chun, M. M. and Mazer, J. A. (2011), Attention doesn't slide: spatiotopic updating after eye movements instantiates a new, discrete attentional locus. Attention, Perception and Psychophysics 73(1):7-14.
- Wang M, Gamo NJ, Yang Y, Jin LE, Wang XJ, Laubach M, Mazer JA, Lee D, Arnsten AF., Neuronal basis of age-related working memory decline. Nature. 2011 Jul 27;476(7359):210-3.
- Golomb, JD, Pulido, VZ, Albrecht, AR, Chun, MM and Mazer, JA (2010), Robustness of the retinotopic attentional trace after eye movements,. Journal of Vision, 10(3):19.1-12.
- Golomb JD, Nguyen-Phuc AY, Mazer JA, McCarthy G and Chun MM. (2010), Attentional facilitation throughout human visual cortex lingers in retinotopic coordinates after eye movements. J. Neuroscience, 40(21):10493-506.
- Haider B, Krause MR, Duque A, Yu Y, Touryan J, Mazer JA and McCormick DA (2010). Synaptic and Network Mechanisms of Sparse and Reliable Visual Cortical Activity during Nonclassical Receptive Field Stimulation, Neuron 65(1):107-121.
- Golomb JD, Chun MM and Mazer JA (2008). The native coordinate system of spatial attention is retinotopic. J Neurosci 28(42):10654-62.
- David SV, Hayden BY, Mazer JA and Gallant JL (2008). Attention to stimulus features shifts spectgral tuning of V4 neurons during natural vision. Neuron. 59(3):509-21.