Neural correlates of acquired color category effects

Abstract

a b s t r a c tCategory training can induce category effects, whereby color discrimination of stimuli spanning a newly learned category boundary is enhanced relative to equivalently spaced stimuli from within the newly learned category (e.g., categorical perception). However, the underlying mechanisms of these acquired category effects are not fully understood. In the current study, Event-Related Potentials (ERPs) were recorded during a visual oddball task where standard and deviant colored stimuli from the same or different novel categories were presented. ERPs were recorded for a test group who were trained on these novel categories, and for an untrained control group. Category effects were only found for the test group on the trained region of color space, and only occurred during post-perceptual stages of processing. These findings provide new evidence for the involvement of cognitive mechanisms in acquired category effects and suggest that category effects of this kind can exist independent of early perceptual processes.Crown

Categorical encoding of color in the brain

“…Electrophysiological studies have claimed that color categories modulate components of visually evoked event-related potentials that potentially arise from the visual cortex (10)(11)(12). However, it has been argued that inequalities in color metric or lack of clarity over the identity and origin of the event-related potential component complicate the interpretation of these findings (8). Using a very different approach, a behavioral-anatomical study found that the learning of novel color names was correlated with gray matter increases in V2/V3 (25).…”

“…The origin and nature of such color categories has been extensively debated across the cognitive sciences (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Traditionally, debate has focused on whether color categories are biologically constrained (2,3), or whether they are arbitrary linguistic constructs that arise out of culture and communication (4).…”

“…Also debated is the extent to which color categories affect how color is perceived. Some have argued that color categories affect the cognitive or attentional strategies of perceptual color judgments (7,8), or that color categories affect early stages of color processing even when colors are not attended (9)(10)(11)(12). However, others have argued that noncategorical sensory models of color encoding are sufficient to account for how color is perceived (13).…”

Color categories only affect post-perceptual processes when same- and different-category colors are equally discriminable

“…There has been uncertainty about whether color category effects really do occur at a perceptual level, as the term "categorical perception" would suggest [11][12][13][14][15]. Psychophysical studies have disagreed whether categorical effects are present at detection threshold [13] or not [14].…”

“…Psychophysical studies have disagreed whether categorical effects are present at detection threshold [13] or not [14]. Distinguishing different-category colors may be easier than same-category colors because the categorical difference enhances attention [15]. Alternatively, a same-category disadvantage could arise because same-category colors have the same name despite being different colors, which leads to conflict at the stage of decision making [11].…”