Selecting and ignoring the component features of a visual object: A negative priming paradigm

Decades of investigation have led to tremendous progress in our understanding of the mechanisms that underlie selective attention to spatial locations and to individual objects. Much less work has been devoted so far to exploring the ability of humans to select the individual features of a multidimensional visual object. Here we report the results of two related experiments in which we used a negative priming procedure to assess whether and under which conditions attention mechanisms can lead to selective processing of the relevant feature of an object (e.g., colour) and/or suppression of the irrelevant features of the same object (e.g., direction of motion or orientation). Results showed that: (1) Individual features of a single object can indeed undergo different processing fates as a result of attention. While one is made available to response selection stages, others are actively blocked. (2) Feature-selective attention most likely operates through a combination of facilitatory and inhibitory mechanisms. (3) In particular, the engagement of inhibitory mechanisms appears to be critically dependent upon the need to resolve response conflict interference between the constituent features of the object. These results are discussed in relation to several ongoing debates concerning the cognitive architecture of attention, including the processing stages at which attentional mechanisms intervene and the types of representation upon which they act