How do different training tasks modulate our perception and hemispheric lateralization in the development of perceptual expertise?

Holistic processing (HP) and hemispheric lateralization are both expertise markers of object recognition. For example, expertise in face and sub-ordinate object perception is shown to be associated with HP and stronger right hemispheric lateralization. However, HP is modulated by experiences of selective attention to parts such as writing experiences of Chinese characters (Tso, Au, & Hsiao, 2014) and drawing experiences of faces (Zhou et al., 2011). Meanwhile, hemispheric lateralization is associated with the decoding strategy employed in object recognition, such as left hemispheric lateralization for reading alphabetic scripts and right hemispheric lateralization for reading logographic scripts. This study aims at training participants to recognize the same sets of artificially-created scripts using either wholeword (Logographic) or grapheme-to-phoneme (Alphabetic) approaches. We found that both approaches induced strong HP, though the alphabetic approach induced stronger left hemisphere advantage than the logographic approach. This training study demonstrates that HP and hemispheric lateralization are separate processes that are associated with different perceptual mechanisms.