Associate Professor Stephen Palmisano
I am an Associate Professor in the School of Psychology. My area of research is 'visual perception'. It examines the 'cues' we use to perceive: (1) the shape and motion of objects; (2) their layout or arrangement in space; and (3) our motion and orientation with respect to this environment.
Research Interests & Example Publications
(A) Visual Perception of Self-motion
One common visual illusion of self-motion occurs when you are seated on a stationary train and the train on the next track pulls out of the station. Because large areas of your visual field are in motion, your brain is fooled into believing that you are moving. The two photos below were taken during an illusory self-motion experiment. The standing observer below is viewing a visual display (a pattern of optic flow) which makes him feel that he is moving. He then sways (back and forth in this case) in response to the visual motion. The amplitude and frequency of his sway is measured by both a force platform (which he is standing on) and lasers pointing to the centre of his back and to his calf. The greater the sway amplitude the better the illusion of self-motion!
Palmisano, S. (1996). Perceiving self-motion in depth: The role of stereoscopic motion and changing-size cues. Perception & Psychophysics, 58(8), 1168-1176.
Palmisano, S., & Gillam, B.J. (1998). Stimulus eccentricity and spatial frequency interact to determine circular vection. Perception, 27(9),1067-1078.
Palmisano, S., Gillam, B.J. & Blackburn, S. (2000). Global perspective jitter improves vection in central vision. Perception, 29(1), 57-67.
Palmisano, S., Burke, D. & Allison, R.S. (2003) Coherent perspective jitter induces visual illusions of self-motion. Perception, 32(1), 97-110.
Palmisano, S., Chan, A.Y.C. (2004). Jitter and size effects on vection are robust to experimental instructions and demands. Perception, 33, 987-1000.
Palmisano, S., & Gillam, B.J. (2005). Visual perception of touchdown point during simulated landing. Journal of Experimental Psychology: Applied, 11(1), 19-32.
(B) Binocular Depth Perception (known as Stereopsis):
Due to our horizontally separated eyes and overlapping visual fields, we simultaneously receive two different 2-D views of the same scene. As a result, the edges of a 3-D object will have slightly different horizontal locations in the two eyes. These binocular disparities provide information about the depth of the object (try to fuse the left and right eye views of the object displayed below).
Magic Eye stereograms were a craze in the mid 80s - the depth in these images is due to stereopsis. One web site which contains many fun examples of these stereograms is Magic Eye Pictures (3-D glasses are not required to view these stereograms).
Most stereoscopic experiments in my laboratory are done using (static or dynamic) random-dot stereograms (which eliminate many of the monocular cues to depth). When the static Random Dot Stereogram below is viewed with Red-blue glasses it will appear to be 3-D (like a corrugated tin roof) due to the binocular disparities in its left and right (or red and blue) images.
Palmisano, S., Allison, R.S., & Howard, I.P. (2000). Effect of disparity noise on stereoscopic surface perception in humans and ideal observers. Proceedings of ICSCC on Intelligent Systems & Applications, 1(2), 1006-1012.
Palmisano, S., Allison, R.S., & Howard, I.P. (2001). Effects of horizontal and vertical disparity noise on stereoscopic corrugation detection. Vision Research, 41(24), 3131-3141.
Palmisano, S., Allision, R.S., & Howard, I.P. (2006). Effects of decorrelation on 3-D grating detection with static and dynamic random-dot stereograms. Vision Research, 46, 57-71.
(C) Object and Face Perception and Recognition:
One problem faced by our visual system is that it must be able to perceive/recognise 3-D objects from the patterns of light projected onto our 2-D retinas. Simone Favelle, Will Hayward, Darren Burke and I have employed change detection and visual search paradigms to isolate the configural and part information that is important in the perception and recognition of novel objects. Simone and I are currently using similar methodology to examine the tolerance of human face perception/recognition to noise (e.g. differences in facial orientation).
Favelle, S., Palmisano, S. Burke, D., & Hayward, W.G. (2006). The role of attention in processing configural and shape information in 3D novel objects. Visual Cognition, 13(5), 623-642.
(D) Perceiving the direction of Gravity:
Physically vertical objects do not always appear to be vertical! Conversely, physically tilted objects sometimes appear to be vertical! These illusions of the direction of gravity are referred to as reorientation illusions. Astronauts and cosmonauts can suffer severely from these illusions because in microgravity there is no input from the other gravity sense organs (the inner ear, somatosensory and proprioceptive systems).
Experiments at the Human Performance Lab at Centre for Vision Research ( Toronto, Canada) are examining whether these 'reorientation' illusions can occur on earth in normal gravity conditions (this is where I did my Post-Doc). Ian Howard's tumbling room apparatus can be used to rotate either the observer or the tumbling room about 1 or more of the 3-Dimensions. The observer typically has to point to where he/she thinks 'down is'. More often than not the observer is wrong (sometimes their errors are as great as 90 DEGREES).
Palmisano, S. A., Allison, R. & Howard, I. (2006). Illusory scene distortion occurs during perceived self-rotation in roll. Vision Research, 46 (23), 4048-4058.
Investigation of Visual Cues for Flare Timing and Control.
Palmisano, S., & Favelle, S. (2006).
Aviation Safety Research Grants Program (ATSB), 2006, $19,000.
Identification and examination of visual cues for aircraft glideslope control
Palmisano, S., & Allison, R.S.
Australian Research Council (ARC) Discovery Grant, 2007-2009, $135,000.
An Investigation of Long Range Stereopsis
Gillam, B.J, Palmisano, S., Allison, R.S
Australian Research Council (ARC) Discovery Grant, 2008-2010, $225,000.
Viewpoint changes during locomotion: Their role in self motion perception and motion
Palmisano, S., Allison, R.S.
Australian Research Council (ARC) Discovery Grant, 2010-2012, $200,000.
Visual perception of smooth and perturbed self-motion in microgravity
Allison, R.S , Palmisano, S.
Canadian Space Agency Grant, 2010-2012, $210,000.
The role of monocular regions in stereoscopic depth perception
Gillam, B.J., Palmisano, S.
ARC Discovery Grant, 2011-2013, $240,000.
Contact: Stephen Palmisano