Barred spirals observed in the mid-infrared

Using ISOCAM observations, we compare the properties of barred and non-barred normal spirals from the point of view of their dust emission in the mid-infrared. In this paper, our aim is to infer some statistical trends in their star formation activities. We have found that a fraction of barred galaxies show an excess of emission around 15 mu m, which is never the case for their unbarred counterparts, and that this is to be found only among early-type systems. Concentrating our analysis on central regions, we interpret such an excess as being due to impulsively heated dust grains, excited to high temperatures by a recent star formation increase triggered by bar-driven gas inflows.