Rosa Lafer-Sousa

Research Area(s)
Perception, Cognition, and Cognitive Neuroscience

Research Interests

Every moment, the human visual system performs a remarkable feat. From the noisy patterns of light that strike the retina, the brain constructs a coherent, colorful world to guide behavior and thought. Understanding how this transformation happens—how the brain turns raw sensory data into perception—is the focus of vision scientist Rosa Lafer-Sousa, a new Assistant Professor in the Department of Psychology and member of the McPherson Eye Research Institute.

Rosa Lafer-Sousa’s lab studies the neural and cognitive mechanisms that underlie perception—how specific brain circuits give rise to what we see, and how prior knowledge and expectations shape that experience, with an emphasis on color as a model system. To uncover how the visual system is functionally organized, how ambiguous sensory signals are resolved, and how perception arises from brain activity, the lab works with human and nonhuman primates, combining psychophysics, brain imaging, electrophysiology, and optogenetics. (Optogenetics is a technique that allows her to activate or silence precise groups of neurons with pulses of light and observe how this alters perception and behavior).

Upcoming projects, will use functional MRI-guided behavioral optogenetics to precisely target and manipulate functionally defined regions of visual cortex, such as those specialized for color, shape, or texture. By observing how these targeted stimulations alter perception and behavior, the lab will test how different parts of the brain causally contribute to our experience of seeing. They will employ innovative behavioral and machine-learning tools, developed with colleagues at NIH, to reconstruct what an animal “sees” during stimulation, creating rich visual “pictures” of perception in real time (“Perceptography”). Future work will deploy concurrent fMRI-optogenetics, to create a whole-brain causal map of visual circuits—an approach that will lay the groundwork for future studies that trace how neural networks generate perception.

By directly linking neural activity to changes in experience, Dr. Lafer-Sousa’s lab is bridging the causal gap between brain and perception. Her integrative approach—connecting behavior, brain, and technology—lays critical groundwork for the development of neural prosthetics that could one day restore sight in individuals with blindness by artificially recreating the brain’s own visual patterns.

The lab is actively recruiting graduate students.

Training

Dr. Lafer-Sousa received her B.A. (in 2009) from Wellesley College with a major in Neuroscience. She carried out her postbaccalaureate training with Dr. Bevil Conway at Harvard Medical School from 2009-2013. She completed her PhD at MIT with Dr. Nancy Kanwisher in 2019. Before joining the faculty at UW–Madison Dr. Lafer-Sousa was Postdoctoral Research Fellow with Dr. Arash Afraz at NIH (NIMH, Laboratory of Neuropsychology, Unit on Neurons, Circuits, and Behavior).

Publications:

To date, Dr. Lafer-Sousa’s most notable work has 1) shed light on the functional architecture of high-level visual cortex (inferior temporal cortex in macaques and ventral temporal cortex in humans), it’s computational goals, and how it evolved (Lafer-Sousa & Conway, 2013; Lafer-Sousa et al, 2016); 2) probed individual differences in color perception and provided evidence that top-down knowledge can influence perception (Lafer-Sousa et al, 2015; Lafer-Sousa and Conway, 2017; Hassantash et al, 2019, Cohen et al, 2025); and 3) established direct causal links between neural activity and perception (Schalk et al, 2017; Azadi et al, 2023; Lafer-Sousa et al, 2023).

Lafer-Sousa, R., Kelemen, L., Swedan, T., Nguyen, D., Azadi, R., Shahbazi, E., Afraz, A. Behavioral detection of optogenetic stimulation in macaque V4 cortex. (in prep)

Cohen, M. A, Rios, A., Min, E., Lafer-Sousa, R. Top-down knowledge can affect perception when the input is ambiguous. Journal of Experimental Psychology (in press)

Lafer-Sousa, R., Wang, K., Azadi, R., Lopez, E., Bohn, S., Afraz, A. Behavioral detectability of optogenetic stimulation of inferior temporal cortex varies with the size of concurrently viewed objects. Current Research in Neurobiology Volume 4, 2023, 100063 https://doi.org/10.1016/j.crneur.2022.100063 (2023)

*Azadi, R., *Bohn, S., Lopez, E., Lafer-Sousa, R., Wang, K., Eldridge, M., Afraz, A. Image-dependence of the detectability of optogenetic stimulation in macaque inferotemporal cortex. Current Biology 33(2) doi: 10.1016/j.cub.2022.12.021 (2023)

*M. Hassantash, *Lafer-Sousa, R., Afraz, A., Conway, B. Paradoxical Impact of memory on color appearance of faces.Nature Communications (2019) (*co-first authors)

Schalk, G., Kapeller, C., Guger, C., Ogawa, H., Hiroshima, S., Lafer-Sousa, R., Saygin, Z.,M., Kamada, K., Kanwisher, N. Facephenes and rainbows: Causal evidence for functional and anatomical specificity of face and color processing in the human brain. Proceedings of the National Academy of Sciences, (46). (2017)

Lafer-Sousa, R. and Conway, B.R. #TheDress: Categorical perception of an ambiguous color image. JOV 17, 25. (2017)

Lafer-Sousa, R., Conway, B.R., and Kanwisher, N.K. Color-biased cortex lies between Face-Selective and Place- selective cortex in humans, as in Macaque monkeys. J Neurosci 36(5): 1682-1697 (2016)

Lafer-Sousa, R., Hermann, K., Conway, B.R. Striking individual differences in color perception revealed by ‘the dress’ photograph. Cur. Biol. 25, R1-R2 (2015)

Hubel, D.H., Wiesel, T., Yeagle, E., Lafer-Sousa, R., and Conway, B.R. Binocular stereoscopy in visual areas V2, V3, and V3A of the macaque monkey. Cereb. Cort. 25(4):959-71 (2015)

Gagin, G., Bohon, KS., Butensky, A., Gates MA., Hu, JY., Lafer-Sousa, R., Pulumo RL., Qu, J., Stoughton, CM., Swanbeck, SN., and Conway, BR. Color-detection thresholds in rhesus macaque monkeys and humans. J Vis. 14(8):12 (2014)

Lafer-Sousa, R. and Conway, B.R. Parallel, multi-stage processing of colors, faces, and shapes in macaque inferior temporal cortex. Nat. Neurosci. 16, 1870–1878 (2013)

Lafer-Sousa, R., Liu, Y.O., Lafer-Sousa, L., Wiest, M.C. and Conway, B.R. Color tuning in alert macaque V1 assessed with fMRI and single-unit recording shows a bias towards daylight colors. J Opt Soc Am A Opt Image Sci Vis 29, 657-70 (2012).

Stoughton, C.M., Lafer-Sousa, R., Gagin, G. and Conway, B.R. Psychophysical chromatic mechanisms in macaque monkey. J Neurosci 32, 15216-26 (2012).

Livingstone, M.S., Lafer-Sousa, R., and Conway, B.R. Stereopsis and Artistic Talent: Poor Stereopsis Among Art Students and Established Artists. Psychol Sci 22, 336-8 (2011). (Highlighted in New York Times).

Lafer-Sousa, R. and Conway, B.R. Vision and Art: An Interdisciplinary Approach to Neuroscience Education. Journal of Undergraduate Neuroscience Education 8, A10-A17 (2009).