How Spatial Frequencies and Visual Awareness Interact During Face Processing

Abstract

In vision, high and low spatial frequencies have been dissociated at the cognitive and neural levels. Usually, high spatial frequency (HSF) is associated with slow analysis along the ventral cortical stream, and low spatial frequency (LSF) is associated with fast and automatic processing. These findings suggest a specific relation between spatial-frequency processing and visual awareness. We investigated this issue using masked-face priming with hybrid prime images of variable visibility. We found subliminal priming for both LSF and HSF information, along with a strong interaction between spatial frequency and visibility: HSF-related priming increased with stimulus visibility, whereas LSF influences remained unchanged. We argue that the results limit the validity of the coarse-to-fine model of vision and of models equating ventral-stream activity with perceptual awareness. Interpreting our results in light of the diagnostic approach suggests a close relation between awareness and diagnosticity.

Subcortical human face processing? Evidence from masked priming.

“…For unknown faces, significant congruence effects were 7 ms and 8 ms (for prime durations of 129 ms and 300 ms, respectively; cf. de Gardelle & Kouider, 2010). Similarly, in Experiment 3 of Finkbeiner and Palermo (2009) the congruence effects were 10 ms, 9 ms, and 8 ms (for the 20 ms, 60 ms, and 100 ms SOAs, respectively).…”

“…This would be in line with the fact that masked HSF primes influence target processing where they are fixated (cf. de Gardelle & Kouider, 2010). Whatever the exact reason, the lack of subliminal priming for HSF faces could not be due to insufficient sex information because these faces were classified into male and female categories just as reliably as LSF faces-but only when they were presented consciously.…”

“…For example, whereas a discrimination between the faces' sexes seems to draw on low spatial frequency content (cf. Schyns & Oliva, 1999), a fame judgment, as it was used in the study of de Gardelle and Kouider (2010), might equally rely on the high spatial frequency band. It is also possible that sensorimotor tasks as in the present study depend stronger on low spatial frequency content than perceptual tasks (as have been used by de Gardelle & Kouider, 2010).…”

“…Schyns & Oliva, 1999), a fame judgment, as it was used in the study of de Gardelle and Kouider (2010), might equally rely on the high spatial frequency band. It is also possible that sensorimotor tasks as in the present study depend stronger on low spatial frequency content than perceptual tasks (as have been used by de Gardelle & Kouider, 2010). However, there is also accumulating evidence that at least unaware discrimination of facial emotional expression could also be carried out along the SC projection (cf.…”

“…If unaware face processing can be driven by the midbrain projection, unaware face priming should be found with masked LSF but not with masked HSF face primes. For example, de Gardelle and Kouider (2010) recently reported subliminal face priming effects with HSF primes. However, they used a fame-judgment task and presented the subliminal faces at fixation.…”