Exploring the effects of chromatic information on separability of face processing dimensions in the Garner speeded classification paradigm (a registered report - stage 1).

Abstract

Garner speeded classification paradigm is widely used to examine whether two perceptual dimensions share cognitive processing mechanisms or operate separately, i.e., to offer evidence for or against the shared and parallel route hypotheses. It has been applied to various face perception dimensions, namely, identity, emotional expression, sex, race, and age. A recent study examining identity and age provided evidence for the shared-route hypothesis of age and facial identity, as shown by substantial Garner Interference. However, they found weaker interference when faces were presented with colour. This raises the possibility that the availability of additional visual information influences how these dimensions are distinguished. Rather than reflecting differences in processing stage, colour stimuli may provide cues that help to selectively emphasise features relevant to a given dimension. In contrast, impoverished stimuli may either fail to provide sufficient information for dimensions to segregate or may artificially promote their separation by constraining observers to rely on the limited cues available. The present registered report proposes three experiments to examine the role of chromatic information in age and identity processing. We expect that colour will help segregate dimension-relevant features, thus reducing interference. Furthermore, we predict that adding colour information for familiar faces will lead to an additional reduction in interference, as it may facilitate the retrieval of features specific to each dimension. If interference, as a measure of separability, is affected by colour, our results will highlight the importance of using naturalistic stimuli, as these may help reveal clearer distinctions between ecologically valid perceptual dimensions