I am planning to conduct a single group meta-analysis that has 2 stimuli, a) test stimuli (TS); b) conditioned stimuli applied with the test stimuli (TS+CS). Some studies reported that the contrast "TS > TS+CS" for activation, but other studies reported that the contrast "TS < TS+CS" for activation. One study reported "TS+CS > Baseline (rest)" is an activation, and "TS+CS < Baseline" is a deactivation. In this scenario, how do I speficy positive  or negative t_threshold value in the "sdm table" for obtaining activation/deactivation results.

Also, not all studies reported the t-threshold directly. So, it was converted it from the z to t-score or p to t-score options using sdmproject.com. While doing so, the study is originally reported as "activation" shows negative t-threshold after convertion. For example, the uncorrected threshold of p < 0.001 with the sample size of 24 indicates the t-threshold -3.48. Does the negative t-threshold mean deactivation? How should I specify the converted t-threshold value in the sdm table?