1. The independent variable was the exposure time to the stimulus that participants were subject to, and had four levels, 200 ms, 500 ms, 1100 ms and 2000 ms. The dependent variable was the grouping response, based on whether the participants grouped the middle column of circles with columns on the left (which suggested grouping by pre-constancy retinal match) or on the right (indicating grouping by post-constancy reflectance match).
2. One limitation of experiment 1 was that participants were constrained by limited exposure time to the stimulus. Thus, most participants may have initially grouped by pre-constancy retinal spectrum due to the lack of time they had to process fine details in the stimulus, thereby…show more content… The experimenters controlled for the confounding variable of stimulus exposure time in experiment 1 by randomly assigning participants to four groups, each of which was subject to a particular stimulus exposure duration, and by giving participants unlimited stimulus exposure time in experiment 2. Further, a control stimuli was used and presented along with the actual experimental stimuli in a random order, to ensure that participants were grouping by similarity. Experiment 2 also used practice trials between actual trials to avoid carryover effects and make sure that the participants understood the task.
4. The preconstancy view of perceptual grouping suggests that objects are grouped together by the properties of their retinal image, before perceptual constancies have been established. According to this view, perceptual grouping operates early on in visual processing, possibly in V1 and V2, before any attention to detail is given. On the contrary, the postconstancy view claims that perceptual grouping takes place after perceptual constancies have been established. Thus, as per this view, grouping operates in the later stages of visual processing (in the V4), once the stimuli are processed…show more content… In the following experiment, I aim to test whether grouping in terms of color similarity is more dominant that grouping by shape similarity. The stimulus used in the study would be a 55 array of elements. Alternating rows of the array would contain elements of different shapes, such that a row of 5 circles would be followed by a row of 5 squares, followed by another row of 5 circles and so on. While the rows are arranged according to shape, the columns would be arranged by alternating color, such that the first column would contain blue colored elements, followed by a column of red colored elements and so on. The independent variable in the study would be the exposure time that participants have to the stimulus. Participants would be shown the stimulus for two different time durations, 200 ms and 2000 ms. The dependent variable would be their response based on how they group the elements together; if shape similarity is more dominant, they would group the elements in rows, whereas color similarity would make them group and see the elements in terms of
