Voluntary Attention Paper

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O’Craven et Al. (1997) challenged the theory of whether earlier cortical areas used in vision processing show the effects of voluntary attention, and specifically did so by testing the effects of voluntary attention on the MT-MST complex which according to past research primarily processes motion elements of stimuli. They tested this specific inference by creating a two paradigm experimental design, one with a fixed stimulus in order to record the modulation of activity based on changes to the stimulus being attended to, and the other a complex stimulus paradigm in order to define the regions under question and allow for quantitative comparisons to be made between the different stimuli being attended to. In this experiment a control group was used verify the lack of eye movement …show more content…

The first experiment consisted of fMRI scans of participants viewing both black and white dots with the white dots moving towards the center of the picture, the fixation point. The participants were ask to switch their focus from either the black or white dots to the opposite every 20s (indicated by an audible tone) for 220s in order to test the signal changes depending on where attention is focused, and the color terms were used rather than “moving” and “non-moving” to eliminate bias. The second experiment also used fMRI scanning and consisted of two groups of subjects, one which focused only on the black dots, and another which only focused on the white dots. The stimuli presented to the subjects consisted of three paradigms, one in which the white dots were moving towards the fixation point at the center of the screen, another in which the black dots are moving towards the fixation point, and finally 20 second intervals of simply stationary black dots innervated the other two paradigms. In experiments two these three paradigms were presented to the subjects

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