  Three nearby galaxies which have abnormally high infrared to radio continuum
ratios, NGC 1377, IC 1953 and NGC 4491, are investigated with a view to
understanding the physical origin of their peculiarity. We review the existing
data and present new radio continuum measurements along with near-infrared
integral-field spectroscopy and molecular gas observations. The three galaxies
have low luminosities but starburst-like infrared colors; in NGC 1377, no
synchrotron emission is detected at any wavelength; in IC 1953, the observed
synchrotron component is attributable to the spiral disk alone, and is lacking
in the central regions; the radio spectrum of NGC 4491 is unusually flat. We
also compare and contrast them with NGC 4418, a heavily extinguished galaxy
which shares some attributes with them. After examining various scenarios, we
conclude that these galaxies are most likely observed within a few Myr of the
onset of an intense star formation episode after being quiescent for at least ~
100 Myr. This starburst, while heating the dust, has not produced optical
signatures nor a normal amount of cosmic rays yet. We briefly discuss the
statistics of such galaxies and what they imply for star formation surveys.
