Letters Response The higher-order view does not require consciously self-directed introspection: response to Malach Hakwan Lau 1, 2 and David Rosenthal 3 1 Department of Psychology, Columbia University, 355D Schermerhorn Ext, 1190 Amsterdam Avenue MC: 5501, New York, NY 10027, USA 2 Donders Institute for Brain, Cognition and Behavior, Radboud University, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands 3 Philosophy Program and Concentration in Cognitive Science, Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016-4309, USA Malach [1] quotes us as defining higher-order representa- tions as ‘‘mental states that represent oneself . . .’’. His ellipsis in this quotation is unfortunate because it creates the misleading impression that higher-order representa- tions are mainly focused on representing the self. Instead, we defined higher-order representations as mental states that ‘‘represent oneself as being in particular perceptual states’’, and emphasized that such higher-order represen- tations need not be themselves conscious [2]. On the view we put forward [2], a perception is conscious only if there is a higher-order representation that one has that perception, but that higher-order representation is itself rarely con- scious (Figure 1a). Our view does not imply that conscious perception requires consciously self-directed introspection (Figure 1b). Ordinary conscious awareness is not atten- tively focused introspection and our view concerns primar- ily this kind of non-introspective conscious awareness. This confusion about the higher-order view lies at the heart of Malach’s critique. It is therefore no problem for the higher-order view that frontal regions associated with consciously self-directed in- trospection [3] were less activated when subjects engaged in processing external stimuli in the Goldberg et al. study [1,4]. As our review made clear [2], these are not the brain regions that we hypothesized to be critical for perception to occur consciously (Figure 1). Distinct prefrontal areas require delineation no less than the various visual areas (e.g.[3]). But even if one inappropriately lumps these distinct regions together loosely as ‘‘frontal regions’’, it is unclear what the Goldberg et al. [4] results tell us. For all we know, even when not actively processing external stimuli, sub- jects may have stimulus-irrelevant but nonetheless vivid conscious visual imagery – about lunch, holidays, etc. The uncontrolled nature of these resting-state studies leads us to agree with Malach that ‘‘these observations are certainly not decisive in favoring one theory over the others’’ [1]. The other part of Malach’s argument is that when subjects are intensely ‘absorbed’ in processing visual input, DLPFC FP First-order state: “motion direction = x, speed = y, …” Higher-order state: “I am seeing this motion” (world-directed, unconscious) Third-order state: “I am having this representation that I am seeing this motion” (self-directed; the absence of this state explains the unconscious nature of the higher-order state) (a) Medial frontal areas (mainly on the medial wall, and small parts of the superior lateral surface) hMT+ Third-order state: “I am having this representation that I, as the experiencer, am having this experience of seeing this motion” (self-directed; the presence of this state is necessary for the higher- order state to be conscious) (b) Higher-order state: “I, as the experiencer, am having this experience of seeing this motion” (self-directed, conscious) First-order state: “motion direction = x, speed = y, …” hMT+ TRENDS in Cognitive Sciences Figure 1. Schematic diagrams of (a) an interpretation of the higher-order view of typical conscious perception, and (b) a common misinterpretation, which elides the difference between ordinary non-introspective conscious awareness and consciously self-directed introspection. Corresponding author: Lau, H. (hakwan@gmail.com); Rosenthal, D. (davidrosenthal@nyu.edu). Update Trends in Cognitive Sciences November 2011, Vol. 15, No. 11 508