I am currently conducting an experiment looking at the effect of visual experience on the development of neural network firing freq. One thing I am interested in knowing is when in development visual experience has an effect.
Since I have 2 independent variables (Age and Rearing condition) I conducted a two-way Anova (type III SS - due to unbalanced groups) in R but i find no interaction between Rearing condition and Age despite there being appearing to be a difference between Rearing condition at 7 dpf (see plot). Could some please explain why I am seeing no effect? Is it due to the variance at 5 dpf being larger than at 3 or 7?
Is a two way Anova the appropriate test to understand when in development visual experience has an effect? or would it be more appropriate to test between rearing conditions at each developmental age and within rearing condition at each age and correct for the multiple comparisons using a bonferroni correction since i am not interested in the comparisons between groups at different ages.