Tim Sweeny


The Whitney Laboratory

Department of Psychology

University of California, Berkeley

I am a post-doctoral researcher in the Psychology Department at the University of California, Berkeley. I received my Ph.D. from Northwestern University in 2010.


3210 Tolman Hall
University of California
Berkeley, CA 94720


Research Program

My research program focuses on a phenomenon I refer to as contextual perception. Go to any crowded intersection and you will appreciate that we often perceive people and objects nearby one another. In this group context, the brain must perform an amazing feat—distinguishing between individuals in the group or, in contrast, seeing the “gist.” My goal is to understand the mechanisms and algorithms that allow us to effortlessly perform these complementary tasks of segmentation and integration. Using psychophysical approaches and computational modeling, I have shown that context is important for perception of emotional expressions and faces, speech and emotional sounds, shapes, and even body movements. My most recent research characterizes the development of these mechanisms in typical children.


Sweeny, T.D., Wurnitsch, N., Gopnik, A., & Whitney, D. Ensemble perception of size in 3-5 year old children. Developmental Science.(In Press)
Sweeny, T.D., & Whitney, D. Perceiving Crowd Attention: Ensemble Perception of a Crowd's Gaze. Psychological Science(Published online)
Piazza, E., Sweeny, T.D., Wessel, D., Silver, M., & Whitney, D. Ensemble coding in audition. Psychological Science(In Press)
Sweeny, T.D., Wurnitsch, N., Gopnik, A., & Whitney, D. Sensitive perception of a person's direction of walking in 4-year-old children. Developmental Psychology. (2013), 49(11): 2120-4.)
Whitney, D., Haberman, J., & Sweeny, T.D. From textures to crowds: multiple levels of summary statistical perception. In J.S. Werner and L.M. Chalupa (Eds.), The New Visual Neurosciences. MIT Press. (In Press)
Sweeny, T.D., Haroz, S., & Whitney, D. Perceiving group behavior: Sensitive ensemble coding mechanisms for biological motion of human crowds. Journal of Experimental Psychology: Human Perception and Performance. (2012), 39(2): 329-37.
Sweeny, T.D., Haroz, S., & Whitney, D. (2012). Reference repulsion in the categorical perception of biological motion. Vision Research, 64, 26-34.
Sweeny, T.D., Grabowecky, M, Paller, K.A., & Suzuki, S. Fleeting emotion detection and expression discrimination. Emotion. (In press)
Sweeny, T.D., Guzman-Martinez, E., Ortega, L., Grabowecky, M., & Suzuki, S. (2012). Speech enhances visual perception. Cognition, 124, 194-200.
Sherman, A., Sweeny, T.D., Grabowecky, M., & Suzuki, S. (2012). Laughter exaggerates happy and sad faces depending on visual context. Psychonomic Bulletin & Review, 19(2), 163-169.
Sweeny, T.D., Grabowecky, M., & Suzuki, S. (2011). Awareness becomes necessary between curvature and aspect-ratio processing. Psychological Science, 22(7), 943-950.
Sweeny, T.D., Grabowecky, M., Kim, Y.J., & Suzuki, S. (2011). Internal curvature noise and signal in low-and high-level vision. Journal of Neurophysiology, 105(3), 1236-1257.
Sweeny, T.D., Grabowecky, & Suzuki, S. (2011). Simultaneous shape-contrast and global-assimilation effects in the perception of aspect ratio. Journal of Vision, 11, 1-16.
Sweeny, T.D., Grabowecky, M., Suzuki, S., & Paller, K.A. (2009). Long-lasting effects of subliminal affective priming from facial expressions. Consciousness and Cognition, 18, 929-938.
Sweeny, T.D., Grabowecky, M., Paller, K.A., & Suzuki, S. (2009). Within-hemifield perceptual averaging of facial expressions predicted by neural averaging. Journal of Vision, 9(3):2, 1-11.
Ruscio, M.G., Sweeny, T.D., Hazelton, J., Suppatkul, P., & Carter, C.S. (2009). Social environment alters central distribution of estrogen receptor-a in juvenile prairie voles. Physiology and Behavior, 98(3), 296-301.
Ruscio, M.G., Sweeny, T.D., Hazelton, J., Suppatkul, P., Boothe, E., & Carter, C.S. (2008). Pup Exposure Elicits Hippocampal Cell Proliferation in the Prairie Vole. Behavioural Brain Research, 187(1), 9-16.
Ruscio, M.G., Sweeny, T.D., Hazelton, J., Suppatkul, P., & Carter, C.S. (2007). Social environment regulates corticotropin releasing factor, corticosterone and vasopressin in juvenile prairie voles. Hormones and Behavior, 51(1), 54-61.