The findings presented by Snowden within his study Visual Attention to Color are extremely intriguing when one considers the history of research on M. stream/P stream activity and attentional guidance. As Snowden states in the Discussion section of his article, "the current finding appears to establish conditions under which a purely chromatic signal can automatically attract attention, and thus shows that color vision can play a vital role in the guidance of visual behavior" (183), and the implications of this result are wide-ranging in terms of their potential application to the study of color vision and colorblindness. By demonstrating that the M. stream is not strictly colorblind, Snowden has opened the doors for a new avenue of visual study, one aimed at determining the link between color vision and attentional guidance. The survival instincts that drove primates to develop the adaptive traits necessary for target detection, identification, and localization still affect many human activities, from sports and recreation to driving safely. By expanding the horizons of examination within the realm of primate visual science, Snowden has continued the progression of empirical knowledge acquisition which is essential to improving understanding of our own sensory processes.
6.) Design an experiment to test whether the parvocellular stream is sensitive to motion processing (maximum 1-page, 7 points as details below)
The following experiment is intended to examine the parvocelluar stream's sensitivity to motion processing relative to the magnocellular stream. Participants in the study will be exposed to a stimulus array containing varying levels of minutely detectable movements, ranging from nearly instantaneous shifts in position to extended movements. Their ability to perceive and respond to these movements using perceptual motion processing will be measured to determine if this phenomenon is generated within the parvocellular stream of vision, in addition to the magnocellular stream. It is expected that the inclusion of certain movement types (zig-zag, random spacing, etc.) will stimulate the parvocellular stream to effect motion processing on a perceptual level.
1.) What methods would you use? (e.g.,...
An array of 12 motion-based stimuli will be presented to each participant on a randomly rotating basis, with each participant viewing all 12 stimuli in random order multiple times to control for the confounding variable of cognitive expectation. The stimulus arrays will be presented via computer screens displaying static images that move in distinct ways (vertically, horizontally, diagonally, etc.), and again each array will be identical in terms of coloration, luminescence, and other visual properties that may present confounding variables. The rate of processing through which each participant reacts to the movement depicted will be measured using mouse-click response time software.
2.) What do you expect to find?
The expectation prior to conducting this experiment is that participants will engage the magnocellular stream when reacting to simple movements, but that complex or apparently random movements will engage the parvocellular stream of perceptual processing. Although Gestalt grouping phenomena are typically associated with the magnocellular stream, multiple studies have confirmed that the parvocellular stream does indeed play a role in perceptual processing. When exposed to movements that are difficult to automatically anticipate, it is expected that participants will rely on the parvocellular stream to detect minute variations in processing.
3.) What would be the implications of your findings? (try to talk about this with regard to the article and sensation/perception in general)
A finding which confirms the original hypothesis would form the basis of further empirical study, as this evidence would only further the emerging school of thought that both the magnocellular and parvocellular streams are crucial to motion processing and other Gestalt vision principles.
References
Snowden, R.J. (2002). Visual attention to color: Parvocellular guidance of attentional resources? Psychological Science,…
