Abstract
A possible consequence of expertise could be a narrowing of the filter that is used to process visual information. To investigate this, we added band-pass filtered noise to faces and fingerprints to determine the range of spatial frequencies that are used during processing. Previous work by Tanskanen, Nasanen, Montez, Paallysaho, and Hari (2005) shows that mid-range spatial frequencies are used during face processing. We hypothesize that fingerprints may require a narrower range of spatial frequencies due to their fine spatial structure. During an XAB experiment, fingerprint experts and novices viewed a stimulus in noise and compared this against a clear target and distractor. The masking effectiveness of each of the seven noise bands describes the width of the visual filter used for each stimulus type in both accuracy and EEG measures. In the expert group, we found overall higher accuracy as well as a narrower filter for fingerprints. EEG data showed similar trends, although the estimation of filter width was noisier for the novice group due to their overall lower accuracy. A second experiment with novices confirmed the wider filter for fingerprints in the novice group. These results suggest that experts rely on a narrower subset of visual information that corresponds to the finer spatial structure of fingerprints. Both behavioral and EEG data for faces showed no differences in the width of the filter for either group, suggesting that broadly tuned filters are necessary for face processing. Thus one consequence of expertise may be the ability to exclude noise from a wider range of spatial frequency bands, and the EEG results suggest involvement of perceptual regions of the brain in this process.
Tanskanen T., Nasanen, R., Montez, T., Paallysaho, J., & Hari, R. (2005). Face recognition and cortical responses show similar sensitivity to noise spatial frequency. Cerebral Cortex, 15, 526-534.
NIJ 2005-MU-BX-K076 NIA/NIH R01 AG 033334-01A2.