EXPERIMENTAL DESIGN AND PROTOCOL
This section discusses the experimental design including the participant details, inclusion and exclusion criteria, sample size computation, design of memory task, and experiment procedure.
In this study, the undergraduate students on the university campus were the target population. All the students on the university campus were the entire set of units for which the findings of the research had been generalized. Equal opportunity was given to all students who met the inclusion criteria to become a participant.
Sample Size Calculation
In terms of the first objective, the outcome of the study was to analyze WM performance with respect to filtering efficiency of the WM. This was achieved by looking at the changes in CDA amplitude with respect to the amount of distraction that was present in the stimuli, and at the same time we measured the WM performance by keeping track of the number of times the participant responded correctly.
Based on the literature, the amplitudes of CDA for stimuli with and without distraction are different. The result of the amplitude in two different situations is:
In terms of the second objective, the outcome of the research was to explore the behavior of CDA when distraction or interruption was presented while the encoded items were being maintained in WM. At the same time, the behavior of CDA could be correlated with the performance of WM, which was pretty close in these two cases. Hence, in this case, we used these percentages of WM performance as the basis to calculate a sample size that could be reliable to compare the performance of WM in these two different situations and be consistent to analyze the neural behavior of the brain as well. Hence we had:
The results were always compared with the reference, which was the no-interruption and no distraction condition. Having said that, the following formula17 was used to compute the sample size for this experiment:
In both cases, the significance level was 0.05, and power was 0.9. Since our test was one-tailed, the normal deviation (Za) for 0.05 significance level (Alpha) was 1.64, and normal deviation Z(-l_p) for statistical power was 1.28. Putting this information and the previous information in the formula, the resulting sample size for each experiment was: