When displaying individual data in a repeated measures variable, usually it is only the single data points that are drawn. However, there is another essential piece of information in the data: What data points belong to the same individual across the variables? This is essential because, in some cases, the difference in the means is not diagnostic of systematic differences. What is diagnostic is whether a large part of the sample differs in a similar direction. See an example in Weissgerber et al. (2015):

Therefore, when displaying individual data in repeated measures variables, it is essential to see how single individuals change across the variables.

Chosen method in CogStat

When displaying individual data in repeated measures variables, the values of the individuals in the neighboring variables are connected (i.e., a spaghetti chart is used).

References

Weissgerber, T. L., Milic, N. M., Winham, S. J., & Garovic, V. D. (2015). Beyond Bar and Line Graphs: Time for a New Data Presentation Paradigm. PLOS Biology, 13(4), e1002128. https://doi.org/10.1371/journal.pbio.1002128