Log(SFR/M_*) and D_n(4000) as a function of stellar masses. Left panels: ringed galaxies in poor groups (represented by blue contours) and their corresponding control sample (represented by gray contours). The side panels show the normalized distributions for each sample. Top-most panel displays the normalized stellar mass distribution for the aforementioned samples. Right panels: same for ringed and non-ringed galaxies in rich groups (represented by magenta and gray contours, respectively).