Electrophysiological evidence for colour effects on the naming of colour diagnostic and noncolour diagnostic objects

Abstract

In this study, we investigated the level of visual processing at which surface color information improves the recognition of color diagnostic and non-color diagnostic objects. Continuous electroencephalograms were recorded while participants performed a visual object naming task in which colored and black-and-white versions of both types of objects were presented. The blackand-white and the color presentations were compared in two groups of event-related potentials (ERPs): (1) the P1 and N1 components, indexing early visual processing; and (2) the N400 component, which index late visual processing. A color effect was observed in the P1 and N1 components, for both color and non-color diagnostic objects. In addition, for color diagnostic objects, a color effect was observed in the N400 component. These results suggest that color information is important for the recognition of color and non-color diagnostic objects at different levels of visual processing. It thus appears that the visual system uses color information, during recognition of both object types, at early visual stages; however for the color diagnostic objects recognition, color information is also recruited during the late visual processing stages. ACKNOWLEDGMENTS

The interplay of holistic shape, local feature and color information in object categorization

“…In the case of intact stimuli, the removal of colors yielded very similar behavioral results in Experiments 1a and 1b (mean accuracy for colorful vs. grayscale images: 93.67% vs. 94.99% and 93.39% vs. 94.38%, respectively), indicating that chromatic information did not influence the classification of intact images (Biederman & Ju, 1988;Bramão et al, 2012;Delorme et al, 2000Delorme et al, , 2010. When compared to color-positive findings regarding object recognition and/or classification (e.g.…”

“…In a similar vein, we expected to observe none or only modest color-related ERP amplitude modulations for intact images. At first glance, this seems to contradict to the results of several ERP studies (Bramão et al, 2012;Lu et al, 2010;Proverbio et al, 2004), but these included easily recognizable isolated objects, for which color effects were also reported on a behavioral level (Bramão et al, 2011;Price & Humphreys, 1989;Rossion & Pourtois, 2004;Tanaka & Presnell, 1999). However, our assumption was based on the vast amount of experimental results pointing toward the primacy of magnocellular processing for natural images (for review see: Fabre- Thorpe, 2011).…”

“…As revealed by the modulation of ERP amplitudes, this effect is present both at the early and late stages of visual processing, and it is relatively independent of target-detection/motor response. Our findings might clarify why several studies have reported the beneficial effect of colors on object recognition and classification (Bramão et al, 2011;Bramão et al, 2012;Hagen et al, 2014;Lu et al, 2010;Price & Humphreys, 1989;Proverbio et al, 2004;Rossion & Pourtois, 2004;Tanaka & Presnell, 1999), whereas those requiring the detection of briefly presented animals in natural scenes concluded that the presence of colors is less important for successful categorization (Delorme et al, 2000(Delorme et al, , 2010Elder & Velisavljević, 2009). It was argued that ultrarapid categorization tasks rely on fast feed-forward processing of achromatic magnocellular information (Delorme et al, 2000;Fabre-Thorpe, 2011) and in this regard, chromatic information that is conveyed by the parvocellular and koniocellular channels seems not to be relevant.…”

“…Indeed, both early and late visual event-related potentials (ERPs) were reported to be sensitive to color information. Amplitudes of both the occipital P1 (evoked between 80 and 140 ms post-stimulus) and N1 (peaking within 130-200 ms) were shown to be modulated by color removal in tasks requiring the recognition of isolated objects (Bramão et al, 2012;Lu et al, 2010;but see: Berninger, Arden, Hogg, & Frumkes, 1989). However, neither the P1 nor the N1 seems to be sensitive to color-typicality effects, i.e.…”

“…In particular, the role of colors in visual processing has been much debated (Bramão et al, 2012;Tanaka, Weiskopf, & Williams, 2001). While it has been proposed that holistic processing depends on global image characteristics such as low spatial frequencies that are associated with the achromatic magnocellular pathway (Kveraga, Boshyan, & Bar, 2007), analytic recognition, which involves the detection of local parts/complex features and their spatial configuration (Biederman, 1987;Ullman, Vidal-Naquet, & Sali, 2002), relies also on signals conveyed by the color-sensitive parvocellular and koniocellular channels (Livingstone & Hubel, 1988).…”