The meaning and significance of Benjamin Libet’s studies on the timing of conscious will have been widely discussed, especially by those wishing to draw sceptical conclusions about conscious agency and free will. However, certain important correctives for thinking about mental states and processes undermine the apparent simplicity and logic of Libet’s data. The appropriateness, relevance and ecological validity of Libet’s methods are further undermined by considerations of how we ought to characterise intentional actions, conscious intention, and what it means to (...) act with conscious intent. Recent extensions of Libet’s paradigm using fMRI and decision-based tasks suffer from similar limitations. The result is that these sorts of laboratory studies of isolated, trivial, decontextualized bodily movements, in a context of extended (conscious) intentional experimental participation and cooperation, are of dubious and potentially misleading relevance to the study of agency. (shrink)

Benjamin Libet has argued that electrophysiological signs of cortical movement preparation are present before people report having made a conscious decision to move, and that these signs constitute evidence that voluntary movements are initiated unconsciously. This controversial conclusion depends critically on the assumption that the electrophysiological signs recorded by Libet, Gleason, Wright, and Pearl are associated only with preparation for movement. We tested that assumption by comparing the electrophysiological signs before a decision to move with signs present before a decision (...) not to move. There was no evidence of stronger electrophysiological signs before a decision to move than before a decision not to move, so these signs clearly are not specific to movement preparation. We conclude that Libet’s results do not provide evidence that voluntary movements are initiated unconsciously. (shrink)

The idea that our conscious decisions determine our actions has been challenged by a report suggesting that the brain starts to prepare for a movement before the person concerned has consciously decided to move . Libet et al. claimed that their results show that our actions are not consciously initiated. The current article describes two experiments in which we attempted to replicate Libet et al.'s comparison of participants' movement-related brain activity with the reported times of their decisions to move and (...) also the reported times of their decisions of which hand to move. We also looked at the distribution of participants' reports over time to evaluate an alternative explanation of Libet et al.'s results. Although the Readiness Potential was usually present before all of the decisions to move, consistent with the findings of Keller and Heckhausen and Libet et al. , we found that many reported decision times were before the onset of the Lateralized Readiness Potential, which measures hand-specific movement preparation. The latter finding is consistent with the conclusion that the LRP always started after the conscious decision to move. We conclude that even though activity related to movement anticipation may be present before a conscious decision to move, the cortical preparation necessary for the movement to happen immediately may not start until after the conscious decision to move. (shrink)

It is generally accepted that there is something special about reasoning by using mental images. The question of how it is special, however, has never been satisfactorily spelled out, despite more than thirty years of research in the post-behaviorist tradition. This article considers some of the general motivation for the assumption that entertaining mental images involves inspecting a picture-like object. It sets out a distinction between phenomena attributable to the nature of mind to what is called the cognitive architecture, and (...) ones that are attributable to tacit knowledge used to simulate what would happen in a visual situation. With this distinction in mind, the paper then considers in detail the widely held assumption that in some important sense images are spatially displayed or are depictive, and that examining images uses the same mechanisms that are deployed in visual perception. I argue that the assumption of the spatial or depictive nature of images is only explanatory if taken literally, as a claim about how images are physically instantiated in the brain, and that the literal view fails for a number of empirical reasons – for example, because of the cognitive penetrability of the phenomena cited in its favor. Similarly, while it is arguably the case that imagery and vision involve some of the same mechanisms, this tells us very little about the nature of mental imagery and does not support claims about the pictorial nature of mental images. Finally, I consider whether recent neuroscience evidence clarifies the debate over the nature of mental images. I claim that when such questions as whether images are depictive or spatial are formulated more clearly, the evidence does not provide support for the picture-theory over a symbol-structure theory of mental imagery. Even if all the empirical claims were true, they do not warrant the conclusion that many people have drawn from them: that mental images are depictive or are displayed in some (possibly cortical) space. Such a conclusion is incompatible with what is known about how images function in thought. We are then left with the provisional counterintuitive conclusion that the available evidence does not support rejection of what I call the “null hypothesis”; namely, that reasoning with mental images involves the same form of representation and the same processes as that of reasoning in general, except that the content or subject matter of thoughts experienced as images includes information about how things would look. (shrink)

Consciousness is a mongrel concept: there are a number of very different "consciousnesses." Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state. The mark of access-consciousness, by contrast, is availability for use in reasoning and rationally guiding speech and action. These concepts are often partly or totally conflated, with bad results. This target article uses as an example a form of reasoning about a function of "consciousness" based on (...) the phenomenon of blindsight. Some information about stimuli in the blind field is represented in the brains of blindsight patients, as shown by their correct "guesses," but they cannot harness this information in the service of action, and this is said to show that a function of phenomenal consciousness is somehow to enable information represented in the brain to guide action. But stimuli in the blind field are BOTH access-unconscious and phenomenally unconscious. The fallacy is: an obvious function of the machinery of access-consciousness is illicitly transferred to phenomenal consciousness. (shrink)

To make progress on the problem of consciousness, we have to confront it directly. In this paper, I first isolate the truly hard part of the problem, separating it from more tractable parts and giving an account of why it is so difficult to explain. I critique some recent work that uses reductive methods to address consciousness, and argue that such methods inevitably fail to come to grips with the hardest part of the problem. Once this failure is recognized, the (...) door to further progress is opened. In the second half of the paper, I argue that if we move to a new kind of nonreductive explanation, a naturalistic account of consciousness can be given. I put forward my own candidate for such an account: a nonreductive theory based on principles of structural coherence and organizational invariance, and a double-aspect theory of information. (shrink)

Eliminativism has been a major focus of discussion in the philosophy of mind for the last two decades. According to eliminativists, beliefs and other intentional states are the posits of a folk theory of mind standardly called "folk psychology". That theory, they claim, is radically false and hence beliefs and other intentional states do not exist. We argue that the expression "folk psychology" is ambiguous in an important way. On the one hand, "folk psychology" is used by many philosophers and (...) cognitive scientists to refer to an internally represented theory of human psychology exploited in the prediction of behavior. On the other hand, "folk psychology" is used to refer to the theory of mind implicit in our everyday talk about mental states. We then argue that sorting out the conceptual and terminological confusion surrounding "folk psychology" has major consequences for the eliminativism debate. In particular, if certain models of cognition turn out to be true, then on some readings of "folk psychology" the arguments for eliminativism collapse. (shrink)

This chapter defends the thesis that Benjamin Libet’s data do not justify his claim that “the brain ‘decides’ to initiate or, at least, to prepare to initiate [certain actions] before there is any reportable subjective awareness that such a decision has taken place” and do not justify associated worries about free will. The data are examined in light of familiar distinctions in action theory: for example, the distinction between deciding and wanting and the distinction between intending and wanting.

This article describes three experiments that would advance our understanding of the import of data already generated by scientific work on free will and related issues. All three can be conducted with existing technology. The first concerns how reliable a predictor of behavior a certain segment of type I and type II RPs is. The second focuses on the timing of conscious experiences in Libet-style studies. The third concerns the effectiveness of conscious implementation intentions. The discussion of first two experiments (...) highlights some important problems with certain inferences made on the basis of existing data in scientific work on free will. The discussion of the third calls attention to powerful evidence that conscious intentions sometimes are among the causes of corresponding actions. This evidence has been largely ignored in the literature on free will. (shrink)

Striking experimental results by Benjamin Libet and colleagues have had an impor- tant impact on much recent discussion of consciousness. Some investigators have sought to replicate or extend Libet’s results (Haggard, 1999; Haggard & Eimer, 1999; Haggard, Newman, & Magno, 1999; Trevena & Miller, 2002), while others have focused on how to interpret those findings (e.g., Gomes, 1998, 1999, 2002; Pockett, 2002), which many have seen as conflicting with our commonsense picture of mental functioning.

Let us begin with what all of us here agree on: folk psychology is not immune to revision. It has a certain vulnerability in principle. Any particular part of it might be overthrown and replaced by some other doctrine. Yet we disagree about how likely it is that that vulnerability in principle will turn into the actual demise of large portions--or all--of folk psychology. I am of the view that folk psychology is here for the long haul, and for some (...) very good reasons. But I am not going to concentrate on that in my remarks. What nobody has bothered saying here yet, but is probably worth saying, is that for all of its blemishes, warts and perplexities, folk psychology is an extraordinarily powerful source of prediction. It is not just prodigiously powerful but remarkably easy for human beings to use. We are virtuoso exploiters of not so much a theory as a craft. That is, we might better call it a folk craft rather than a folk theory. The theory of folk psychology is the ideology about the craft, and there is lots of room, as anthropologists will remind us, for false ideology. (shrink)

If the notion of free will is to be retained by philosophers, psychiatrists and psychologists, then it will be a free will which is essentially non-conscious. The purpose of this paper is to demonstrate that a conscious free will (in the sense of consciousness initiating action) is incompatible with the evidence of neuroscience, and the phenomenology described in the literature of normal creativity, psychotic passivity, and the neurological syndrome of the alien limb or hand. In particular the work of Libet (...) and others who have directly stimulated the brain and measured activity from its surface leads to the conclusion that subjective states (be they sensory or intentional) are preceded by predictive neural activity. Subjective phenomenology is temporally distinct from the initiation of “voluntary” action. In addition it will be argued that free will is more than a belief and that it comprises a perceptual sensorimotor component. Free will is conceptualized as a three component phenomenon consisting of a perceptual, non-linguistic experience of freedom, an experiential belief which is linguistic, and related to a specified action in time, and an abstract belief which is linguistic but remote from any particular action and akin to philosophical discourse (the abstract belief or otherwise, in free will). A theoretical explanation of some of the pathological phenomenology of possession of action is offered in terms of temporal considerations. The direction of action within mental/virtual space is hypothesized to be a function of the temporal sequence of its initiation and awareness of the latter “reaching” consciousness. It is suggested that perturbation of this temporal sequence may lead to the misattribution of host-as-alien-initiated action. Work of this kind, which is beyond subjective introspection, is necessary if we are to develop adequate models to use in conjunction with modern investigation techniques. (shrink)

Brain images are used both as scientific evidence and to illustrate the results of neuroimaging experiments. These images are apt to be viewed as photographs of brain activity, and in so viewing them people are prone to assume that they share the evidential characteristics of photographs. Photographs are epistemically compelling, and have a number of characteristics that underlie what I call their inferential proximity. Here I explore the aptness of the photography analogy, and argue that although neuroimaging does bear important (...) similarities to photography, the details of the generation and analysis of neuroimages significantly complicate the relation of the image to the data. Neuroimages are not inferentially proximate, but their seeming so increases the potential for misinterpretation. This suggests caution in appealing to such images in the public domain. (shrink)