HEMISPHERIC ASYMMETRIES IN THE IDENTIFICATION OF BAND-PASS FILTERED LETTERS

Processing of band-pass filtered letters in the left versus right cere bral hemispheres (LH vs. RH) was examined. The present experiments con stituted a partial replication of a study in which Peterzell, Harvey, and Hardyck (1989) found no hemispheric differences in accuracy or rea ction time CRT) as a function of spatial frequency. However, methodolo gical Limitations of their study (e.g., the possibility that subjects were engaged in a detection, not identification, task) may have obscur ed possible hemispheric differences. We addressed these problems in th e present study, obtaining significant hemisphere x spatial frequency interactions for RT and d' with RH advantages at low frequencies and L II advantages at high frequencies; however, these effects were not lar ge in magnitude and were often restricted to particular dependent vari ables, stimulus sizes, and so forth. Hemispheric differences in respon se bias were also found.