Authors:

MOUCHLIANITIS, E. & HENSON, R.N.A.

Reference:

Year of publication:

2008

CBU number:

6765

Abstract:

Our previous studies on repetition priming of faces (Mouchlianitis & Henson, in prep) found larger priming effects when a central prime was followed by a probe lateralised to the right visual-field (left-hemisphere, LH) than a probe lateralised to the left visual-field (RH). Bourne & Hole (2006), on the other hand, found greater priming for the RH than LH when using lateralised primes followed by a central probe. We proposed that both these findings can be explained by the RH advantage in face-processing, which causes the RH advantage at encoding found by Bourne & Hall, but paradoxically a LH advantage following (central) face encoding, owing to the LH benefiting from priming to a greater extent than the RH, in which face processing may already be close to optimal. This proposal was supported by priming effects in a number of behavioural experiments that explicitly crossed the lateralisation of the prime and the lateralisation of the probe. These experiments were then extended for use in fMRI, with the addition of non-face control stimuli. Surprisingly, despite main effects of visual-field and of stimulus-type (face vs house), there was no evidence for an interaction, in either left or right FFA (and despite overall greater activity in the right than left FFA). In other words, the face-house difference in FFA did not appear greater for left than right visual field presentations. Moreover, no priming effects reached significance. This lack of reliable modulation of face-processing by visual hemifield may reflect the limited temporal resolution of fMRI, which has prompted subsequent MEG versions of the experiments.