We watched and discussed most part of Charlie Rose Brain Series - Episode 2: "The Perceiving Brain". One controversial aspect was that surgery for squint (strabismus) correction may not be of benefit after a critical period. However see this article for a differing opinion. Overall, an excellent introduction to visual perception.
Dr. Shwetha Shankar (Wake Forest School of Medicine) presented her work on "Time course of a Perceptual Judgement and Factors affecting it" .
While, Reaction time (RT) studies have been in vogue for a long time, Donders was the first to try and get to extract processing time (time taken to identify the target) in the 1880s. The subtraction approach however has a number of limitations - there are multiple covert factors at play, high variability and speed-accuracy trade-offs that take place. Also visual stimuli tend to leave a after-image so the timing is unpredictable. To counter this people have tried using mask images but that introduces other confounds.
Shwetha's group used a compelled-saccade task with a variable gap time between go and cue images to arrive at processing time (reaction time - gap time). They also created a Tachometric curve (with centre point, slope/rise time and maximum height) that graphed %correct responses as a function of processing time. This approach yields much more information than reaction time or psychometric curve (%correct vs gap time) studies.
They manipulated three factors (motivation; stimulus discrimination and features; perceptual learning) that affect perception to see how the tachometric curve responds.
Areas that need further work include effect of expectation, multisensory decision making and neural correlates of perceptual changes (areas and mechanisms).
Dr. Arun Sasidharan (2nd year PhD scholar) presented his seminar on "Neurobiology of Perception, Attention and Consciousness" on 25th Nov, 2011. He tried to link the three phenomena into a continua, giving examples from visual perception. The concept of Qualia was also explained, and used it to address the hurdles confronted by neuroscience in the quest for Neural correlates of Consciousness. There were some thought provoking debates regarding the contribution by computational methods and