A central debate in philosophy and neuroscience pertains to whether PFC activity plays an essential role in the neural basis of consciousness. Neuroimaging and electrophysiology studies have revealed that the contents of conscious perceptual experience can be successfully decoded from PFC activity, but these findings might be confounded by post- perceptual cognitive processes, such as thinking, reasoning, and decision-making, that are not necessary for con- sciousness. To clarify the involvement of the PFC in consciousness, we present a synthesis of research (...) that has used intracranial electrical stimulation (iES) for the causal modulation of neural activity in the human PFC. This research provides compelling evidence that iES of only certain prefrontal regions (i.e., orbitofrontal cortex and anterior cingu- late cortex) reliably perturbs conscious experience. Conversely, stimulation of anterolateral prefrontal sites, often con- sidered crucial in higher-order and global workspace theories of consciousness, seldom elicits any reportable alterations in consciousness. Furthermore, the wide variety of iES-elicited effects in the PFC (e.g., emotions, thoughts, and olfactory and visual hallucinations) exhibits no clear relation to the immediate environment. Therefore, there is no evidence for the kinds of alterations in ongoing perceptual experience that would be predicted by higher-order or global workspace theories. Nevertheless, effects in the orbitofrontal and anterior cingulate cortices suggest a specific role for these PFC subregions in supporting emotional aspects of conscious experience. Overall, this evidence presents a challenge for higher-order and global workspace theories, which commonly point to the PFC as the basis for con- scious perception based on correlative and possibly confounded information. (shrink)

According to Milner and Goodale’s dual visual systems (DVS) theory, a division obtains between visual consciousness and motor action, in that the visual system producing conscious vision (the ventral stream) is distinct from the one guiding action (the dorsal stream). That there would be this division is often taken (by Andy Clark and others) to undermine the folk view on how consciousness and action relate. However, even if this division obtains, this leaves open the possibility that con- scious ventral information (...) is often transmitted to the uncon- scious dorsal stream and then used to guide action, a possibility seeming to preserve a significant role for consciousness in action. This article assesses this possibility. In course of doing so, we will review those arguments recently having been made against the DVS view on how visual consciousness and action relate (ones due to, e.g., Briscoe and Schwenkler, or Schenk and McIntosh). What we will find is that, if we properly analyze the data upon which these arguments are based, we are still left with the impression that the DVS view is largely correct; i.e., it is only rarely that visual experience guides action. (shrink)

Common sense suggests that visual consciousness is essential to skilled motor action, but Andy Clark—inspired by Milner and Goodale's dual visual systems theory—has appealed to a wide range of experimental dissociations to argue that such an assumption is false. Critics of Clark's argument contend that the content driving motor action is actually within subjects' experience, just not easily discovered. In this article, I argue that even if such content exists, it cannot be guiding motor action, since a review of current (...) visual neuroscience indicates that the visual brain areas producing conscious representations are distinct from those driving motor action. (shrink)

Local Recurrency Theory (LR) holds that recurrent loops of neural activity localized to the visual cortex are necessary and sufficient for visual consciousness (if certain background conditions obtain). LR’s popularity has recently waned in favor of theories holding that higher-level types of processing are necessary for consciousness (for example, the Global Neuronal Workspace Theory and Higher-order Theory). This has been in part because of empirical evidence thought to disconfirm LR. However, these competing theories now face challenges of their own, often (...) coming in the form of evidence showing that higher-level brain areas (that is, in the prefrontal cortex) are probably not essential for consciousness. Given growing challenges to LR's competitors, it would be timely to re-assess the prospects for LR. This article carries out such an investigation, first laying out the theory precisely, then going on to survey the evidence presented against it. What will be found is that none of the evidence necessarily undermines LR, but instead just fosters its theoretical enrichment. The overall conclusion: LR remains among our most promising neuroscientific theories of visual consciousness. (shrink)

Proponents of the higher‐order (HO) theory of consciousness (e.g., Lau and Rosenthal) have recently appealed to brain lesion evidence to support their thesis that mental states are conscious when and only when represented by other mental states. This article argues that this evidence fails to support HO theory, doing this by first determining what kinds of conscious deficit should result when HO state‐producing areas are damaged, then arguing that these kinds of deficit do not occur in the studies to which (...) HO theorists appeal. The article also develops an apparatus that can be used to evaluate whether other lesion evidence confirms or disconfirms HO theory. (shrink)

Is perceptual processing in dedicated sensory areas sufficient for conscious perception? Localists say ‘Yes—given some background conditions.’ Prefrontalists say ‘No: conscious perceptual experience requires the involvement of prefrontal structures.’ I review the evidence for prefrontalism. I start by presenting correlational evidence. In doing so, I answer the ‘report argument’, according to which the apparent involvement of the prefrontal cortex in consciousness stems from the requirement for reports. I then review causal evidence for prefrontalism and answer the ‘lesion argument’, which purports (...) to show that prefrontalism is wrong because lesions to the prefrontal cortex do not abolish consciousness. I conclude that multiple sources of evidence converge toward the view that the prefrontal cortex plays a significant role in consciousness. (shrink)

Several well-known theodicies, whatever their merits, seem to make little sense of animal suffering. Here we argue that the problem of animal suffering has more layers than has generally been acknowledged in the literature and thus poses an even greater challenge to traditional Judeo-Christian Theism than is normally thought. However, the Neo-Cartesian (NC) defence would succeed in defanging this Expanded Problem of Animal Suffering. Several contemporary philosophers have suggested that recent evidence either supports the NC view or at least should (...) decrease our incredulity with respect to it. We discuss new evidence that undermines the NC position and thus reassert the gravity of the Expanded Problem. (shrink)

Darwin’s theory is often illustrated with depictions of different finch beaks or with lined-up skeletons displaying subtle bone-structure changes throughout evolutionary history. In The Deep Histor...

Higher-order thought (HOT) theory says that a mental state is conscious when and only when represented by a conceptual, belief-like mental state. Plausibly, HOT theory predicts the impairment of HOT-producing brain areas to cause significant deficits in consciousness. This means that HOT theory can be refuted by identifying those brain areas that are candidates for producing HOTs, then showing that damage to these areas never produces the expected deficits of consciousness. Building this refutation is a work-in-progress, with several key components (...) of it already existing in the literature (e.g., Boly et al. in J Neurosci 37(40):9603–9613, 2017; Kozuch in Mind Lang, 37(5):790–813, 2022). This article pulls together and supplements these earlier components so as to provide a comprehensive lesion-based argument against HOT theory, one which offers extra data and arguments in support of it, and which also addresses common objections. (shrink)

The problem of higher-order misrepresentation poses a dilemma for the higher-order theory of consciousness. The two ways of conceiving of the theory each run into a different difficulty raised by the problem of misrepresentation. If the theory is conceived relationally, i.e., conceived so as the higher-order state causes or makes a first-order state conscious, then the theory faces a problem raised by Block concerning the implausibility of non-existent conscious states. If conceived non-relationally, i.e., conceived in such a way as it (...) is the higher-order state itself which is the conscious state, then consideration of Neander’s original misrepresentation problem, that this seems to make the first-order state a spinning wheel in the explanation of consciousness, raises the conceptual problem that this version of the higher-order theory seems not to offer a philosophical theory of consciousness that is distinct from the first-order theory. (shrink)

Some proponents of the higher-order thought theory of consciousness defend the view that higher-order misrepresentation is possible. In support of this view they have proposed various pieces of empirical evidence. This paper examines one such piece of proposed empirical evidence; Change blindness. CB occurs when a subject fails to detect salient changes in visual scenes. I propose an alternative interpretation of the CB phenomenon on which misrepresentation does not occur. Finally, I examine three lines of reply that might be pursued (...) to defend the claim that CB is evidence of misrepresentation against my interpretation. I conclude that none of the lines of reply succeed in preserving CB as evidence of misrepresentation. The upshot is that, pending further evidence, CB cannot be deployed as empirical evidence in the debate on misrepresentation. (shrink)

I present an empirically based argument for the plausibility of misrepresentation as posited by some higher-order theories of consciousness. The argument relies on the assumption that conscious states are generated by processes in the brain. The underlying idea is that if the brain generates conscious states then misrepresentation may occur. The reason for this is that brain states can be corrupted and, accordingly, a conscious state that is at least partly caused by a corrupted brain state may be a misrepresentation. (...) Our body of knowledge from cognitive and behavioral neuroscience lends support to the idea that corruption of neural states is both possible and relatively frequent. If this is the case, I argue, it is plausible that occasionally such corruption may result in misrepresentation. I support this claim by arguing that the most prevalent theoretical alternative to the occurrence of misrepresentation—the so-called no-consciousness reply—seems less supported by our current knowledge in the domain of consciousness and cognition. This way of arguing for misrepresentation is different from other empirically based arguments in the debate because it is a meta-level argument resting on a general premise that most participants in the debate can accept. (shrink)