RESPONSE Intrinsic Perspectives, Object Feature Binding, and Visual Consciousness

ABSTRACT. Van der Velde and I agree on two fundamental issues surrounding the vision-related binding problem and recent solutions that have been offered: (1) that tagging theories, such as neuronal synchrony, fail to account for object feature binding in visual consciousness; and (2) that feedforward– feedback processes in the visual cortical hierarchy play a role in generating a feature-unified object of visual consciousness. Van der Velde develops and dis-cusses an important objection to tagging theories that could help to strengthen my critique of neuronal synchrony (and other tagging theories), and then argues that the cognitive subject makes no explanatory contribution to the unity of an object’s features in visual consciousness. These issues are dis-cussed in turn. By contrast, van Leeuwen takes a more critical approach to my article. A two-fold response to van Leeuwen is offered: first, the root of his perplexity is uncovered and then some specific objections that he poses to my critique of neuronal synchrony, as a purported solution of the object feature binding problem, are addressed. KEY WORDS: binding, cognition, consciousness, diachronic object unity, object representation, tagging theories Conversing with van der Velde: IPO and the Cognitive Subject The first issue that van der Velde (2007) raises is that I have overlooked an important reason why tagging theories, like synchrony of activation, fail to explain object feature binding in visual consciousness. What I have over-looked in my critical examination of tagging theories could be called the intrinsic perspective objection (hereafter IPO). Much of van der Velde’s com-mentary is built around this concern, so I will focus most of my attention upon it. Van der Velde argues that a fundamental reason why tagging theories fail to explain the unity of an object’s features in visual consciousness is that these theories are motivated by and essentially linked to considerations drawn from the extrinsic perspective. Neuroscientists can make observations o