Visual Perception and Illusions

During my time at UC San Diego, I was fortunate to have taken many classes taught by Stuart Anstis, VS Ramachandran, and Diana Deutsch. Their approach in using illusions as a tool to reverse-engineer the perceptual system left a deep impression in me. I remember being bewildered by all the visual and auditory illusions that were shown in class, and decided that psychology would be my choice of career. I am now also teaching the Sensation & Perception class at TMU. 

Here at TMU I also lead a group of undergraduate students to investigate the different conditions that are necessary for various visual/auditory illusions to occur. Some examples can be found on Yi-Tsen Kuo's website here.

My other work in this area have mostly focused on the amount of unconscious processing that can be done without subjective awareness. For example, spatial layout of distractors in a visual search task can be learned and used unconsciously  (contextual cueing) with probabilistic memory strength (Tseng et al., 2011), a slightly shifted frame can be processed unconsciously and affect subsequent spatial judgments (Lathrop et al., 2011), action-related information can be processed and remembered to enhance guessing performance (Tseng et al., 2010). In addition, we have also done some interesting work in synaesthesia and bistable illusions. For example, grapheme-color synaesthetes would experience a change in color percept when they look at a rotating letter that changes its identity as it rotates (e.g., a letter E rotating clock-wise would become letter M, number 3, and letter W), but only if they consciously recognize that letter/number in that new identity in the first place (Bridgeman et al.,, 2010). Lastly, using a bistable silhouette spinner animation and eye tracker we have also found that most participants feel that they can use their willpower to change the spinner's 'switch' rate, and they are indeed correct, but what they don't know is that they are doing so by selectively looking at the body or the feet of the spinner, which decreases and increases the switch rate, respectively, for some reason (Liu et al., 2012).


For some still-image demos, see 

Tseng, P., Juan, C.H. (2013) Virtual reality in the neuroscience of multisensory integration and consciousness of bodily self. Journal of Neuroscience and Neuroengineering, 2(4), 387-392. [PDF]

Liu, C.H., Tzeng, O.J.L., Hung, D.L., Tseng, P., Juan, C.H. (2012) Investigation of bistable perception with the "silhouette spinner": Sit still, spin the dancer with your will. Vision Research, 60, 34-39. [PDF]

Tseng, P., Hsu, T.Y., Tzeng, O.J.L., Hung, D.L., Juan, C.H. (2011) Probabilities in implicit learning. Perception, 40, 822-829. [PDF]

Lathrop, B., Bridgeman, B., Tseng, P. (2011) Perception in the absence of attention: evidence of perceptual processing in the roelofs effect during conditions of inattentional blindness. Perception, 40, 1104-1119. [PDF]

Tseng, P., Tuennermann, J., Roker-Knight, N., Winter, D., Scharlau, I., Bridgeman, B. (2010) Enhancing implicit change detection through action. Perception, 39,1311-1321.

Bridgeman, B., Winter, D., Tseng, P. (2010) Phenomenology of grapheme-color synesthesia. Perception, 39, 671-676. [PDF]