Perception and Cognition
PSY 101 - Introductory Psychology
PSY 361 - Perception
PSY 492 - Advanced General Capstone
I have studied a variety of phenomena that shed light on mechanisms of visual perception. One earlier study has to do with visual sensory adaptation. It is known that a steady stimulus in peripheral vision will fade from awareness in a few seconds. This phenomenon, known as the Troxler effect, is commonly believed to result from overstimulation of lower level visual system neurons. I demonstrated, however, that when a complex stimulus is viewed in the peripheral visual field, those elements that are selectively attended fade faster than others that are ignored (Lou, 1999). What this finding suggests is that the signals feeding the sensory adaptation mechanism can come from both the eyes and the higher level visual system neurons involved in selective attention. My other significant studies on visual perception include those concerning how attention influences phenomenal filling-in of the physiological blind spot (Lou & Chen, 2003), how the apparent size of an afterimage changes with oculomotor cues (convergence and accommodation) (Lou, 2007), and how the Troxler effect also has to do with both innerocular suppression and inhibitory summation across the two eyes and their brain pathways (Lou, 2008).
Currently, my research is focused on issues related to the duality of visual perception----the proximal mode of seeing, or seeing of image attributes that are view and illumination dependent, and the distal mode of seeing, or seeing of object attributes that are view and illumination independent. While it is indisputable that both types of attributes are perceivable and probably conjoined phenomenally, most modern scientific researches on visual perception have been focused on the distal mode of seeing, or perceptual constancies. However, the proximal mode of seeing could be the dominant mode of seeing in observational drawing and painting, or drawing and painting from life and real scenes. Partly rooted in my previous studies on the apparent size of the after-images, and partly related to my interest and practice in painting, I am working on a theoretical model of observational drawing that encompasses both modes of seeing and empirically testing predictions that follow from the model. The insight gained from the studies on visual perception in drawing and painting may impact theoretical understandings of visual perception in general and the relationships between visual perception and mental imagery.
Another line of my research intersects visual perception and political psychology, the immediate goal of which being to understand whether political attitudes and orientations can be perceived from human faces. I have conducted a series of empirical studies to address some basic issues in this research area, such as the potential biases in such perception due to the political leanings of the perceivers, and the need to separate the effects of facial emotional expressions from those of physiognomies.
(Some of these papers can be downloaded for personal use. If you would like permission to use a reprint for a book or course pack, please contact the publisher)
Lou, L. (2014). What is the Pictorial Mode of Seeing? Presented at the 2nd Visual Science of Arts Conference, Belgrade, Serbia
Lou, L. (2014). Can Political Orientation be Perceived from Faces? Presented at the 2nd Conference of Psychology and Social Harmony, SuZhou, China
Lou, L. (2008). Troxler effect with dichoptic stimulus presentations: Evidence for binocular inhibitory summation and interocular suppression. Vision Research, 48(14), 1514-1521.
Lou, L. (2007). Apparent afterimage size, Emmert's law and oculomotor adjustments, Perception, 36, 1214-1228.
Lou, L., & Chen, J. (2003) Attention and blind-spot phenomenology, Psyche: An Interdisciplinary Journal of Research on Consciousness, 9(2), http://www.theassc.org/files/assc/2562.pdf
Lou, L. (2001). Effects of voluntary attention on structured afterimages. Perception, 30(12), 1439-1448. pdf
Lou, L. (1999). Selective peripheral fading: Evidence for inhibitory sensory effect of attention. Perception, 28(4), 519-526. pdf
Lou, L. (1999). Selective peripheral fading: How attention leads to loss of visual consciousness. In[S. R. Hameroff, A. W. Kaszniak, D. Chalmers Eds.] Toward a Science of Consciousness: The Third Tucson Debates and Discussions, MIT Press pp189-196.