Question about 3X3 repeated measures ANOVA and simple effects

First time posting here.

I have conducted a transcranial magnetic stimulation study and am analyzing the results as a 3x3 repeated measures ANOVA. I'm a grad student in cognitive psychology.

1. purpose of the study: to dissociate language from other forms of cognition using TMS.

2. nature of the data: dependent variables are accuracy, reaction time, and reaction time variability. Independent variables are stimulation site (what part of the brain) and task type (what kind of cognitive task is being performed). Another potential IV is level of complexity of the task.

3. how the variables are being measured: participants performed cognitive tasks on a laptop.

THE PROBLEM: In the presence of a significant interaction, with rm ANOVA should the simple effects (or the lack thereof) be reported? I have seen conflicting information about this. At least one source (Laerd) seems to say that when the two IV's have more than two levels (each of mine has 3) that simple effects should not be analyzed.

I'm doing this in SPSS.

Thanks in advance!