We are conducting an experiment where we want to assess event related stress responses; we're separating the data into phasic and tonic components via continuous deconvolution analysis, where only the phasic components will be analyzed. We're looking at the "Phasic Max" component, but a lot of our values are coming out negative and we're not sure why. This population is in older adults, so we're thinking maybe during the analysis step, we need different tau values/IRF values but we're not sure how...