How does the brain generate our experience of being in control over our actions and their effects? Here, we argue that the perception of events as self-caused emerges from a comparison between anticipated and actual action-effects: if the representation of an event that follows an action is activated before the action, the event is experienced as caused by one’s own action, whereas in the case of a mismatch it will be attributed to an external cause rather than to the self. (...) In a subliminal priming paradigm we show that participants overestimated how much control they had over objectively uncontrollable stimuli, which appeared after free- or forced-choice actions, when a masked prime activated a representation of the stimuli immediately before each action. This prime-induced control-illusion was independent from whether primes were consciously perceived. Results indicate that the conscious experience of control is modulated by unconscious anticipations of action-effects. (shrink)

The belief in free will has been frequently challenged since Benjamin Libet published his famous experiment in 1983. Although Libet’s experiment is highly dependent upon subjective reports, no study has been conducted that focused on a first-person or introspective perspective of the task. We took a neurophenomenological approach in an N = 1 study providing reliable and valid measures of the first-person perspective in conjunction with brain dynamics. We found that a larger readiness potential is attributable to more frequent occurrences (...) of self-initiated movements during negative deflections of the slow cortical potentials . These negative deflections occur in parallel with an inner impulse reported by an expert meditator which may in turn lead to a voluntary act. We demonstrate in this proof-of-principle approach that the first-person perspective obtained by an expert meditator in conjunction with neural signal analysis can contribute to our understanding of the neural underpinnings of voluntary acts. (shrink)

Lucid dreaming refers to a dream state characterized by the dreamers awareness of being in a dream and being able to volitionally control its content. The aim of this study was to find neurophysiological evidence for the 7 criteria of lucid dreaming proposed by Paul Tholey. Each of the criteria was analyzed separately with regard to its underlying neurocircuits. We hypothesized that not one, but many regions are involved in the state of lucid dreaming. Our results have shown a satisfactory (...) overlap of the theoretical components and the brain regions activated during a lucid dream. During lucid dreaming, a brain network seems to emerge, that is more than the sum of its parts. Further research is needed to understand the psychoneurological underpinnings of lucid dreams. (shrink)

An extended examination of Libet's works led to a comprehensive reinterpretation of his results. According to this reinterpretation, the Minimum Train Duration of electrical brain stimulation should be considered as the time needed to create a brain stimulus efficient for producing conscious sensation and not as a basis for inferring the latency for conscious sensation of peripheral origin. Latency for conscious sensation with brain stimulation may occurafterthe Minimum Train Duration. Backward masking with cortical stimuli suggests a 125-300 ms minimum value (...) for the latency for conscious sensation of threshold skin stimuli. Backward enhancement is not suitable for inferring this latency. For determining temporal relations between stimuli that correspond to subjects' reports, theendof cerebral Minimum Train Duration should be used as reference, rather than its onset. Results of coupling peripheral and cortical stimuli are explained by a latency after the cortical Minimum Train Duration, having roughly the same duration as the latency for supraliminal skin stimuli. Results of coupling peripheral stimuli and stimuli to medial lemniscus (LM) are explained by a shorter LM latency and/or a longer peripheral latency. This interpretation suggests a 230 ms minimum value for the latency for conscious sensation of somatosensory near-threshold stimuli. The backward referral hypothesis, as formulated by Libet, should not be retained. Long readiness potentials preceding spontaneous conscious or nonconscious movements suggest that both kinds of movement are nonconsciously initiated. The validity of Libet's measures of W and M moments (Libet et al., 1983a) is questionable due to problems involving latencies, training, and introspective distinction of W and M. Veto of intended actions may be initially nonconscious but dependent on conscious awareness. (shrink)

A commentary on articles by Klein, Pockett, and Trevena and Miller, in this issue, is given. Average shift in the point of subjective equality , calculated by Klein on Libet's data, and corresponding change in mean shift, calculated by Libet et al. , may be “corrected,” taking as a reference point the end of the minimum train duration. Values obtained, if significant, indicate a latency for conscious sensation of the skin stimulus of at least 230 ms. Pockett's main conclusions are (...) favored, but her explanation of peripheral–lemniscal couplings is found to be unconvincing. Trevena and Miller's article unsuccessfully tries to rescue a dualist interactionist view. Libet's method of timing intentions is thoroughly criticized. (shrink)

A commentary is given on Trevena and Miller . The comparability of their experimental task and of the potential they recorded with those used and recorded by Libet, Gleason, Wright, and Pearl is questioned. An interpretation is given for the similarity of event-related potentials recorded when subjects decided to move and when they decided not to move.

Neuroscientists frequently use two folk psychology terms –self and consciousness– in formulating decision-making process models. According to Daniel Dennett, such notions lead them to dualistic view of brain functions and hence to dead ends or, at least, to less than optimal designs in the research field. Indeed, Dennett’s position offers interesting insights that may help neuroscientists to comprehend the distinction between conscious and non-conscious behavior. In this paper, I first explore how habitual behavior could be defined from Dennett’s model. Second, (...) taking his view into account, I try to offer a better interpretation of habits. Particularly, I define habits as involving a teleological and preconscious process whose traits and dynamics are indistinguishable from computational ones, but this is so more in their ends than in their origins. Finally, I propose seven lines of experimental hypothesis to support this definition. (shrink)

Time is a fundamental dimension of consciousness. Many studies of the “sense of agency” have investigated whether we attribute actions to ourselves based on a conscious experience of intention occurring prior to action, or based on a reconstruction after the action itself has occurred. Here, we ask the same question about a lower level aspect of action experience, namely awareness of the detailed spatial form of a simple movement. Subjects reached for a target, which unpredictably jumped to the side on (...) some trials. Participants (1) expressed their expectancy of a target shift during the upcoming movement, (2) pointed at the target as quickly and accurately as possible before returning to the start posiment to the target shift if required and (3) reproduced the spatial path of the movement they had just made, as accurately as possible, to give an indication of their awareness of the pointing movement. We analysed the spatial disparity between the initial and the reproduced movements on those with a target shift. A negative disparity value, or undershoot, suggests that motor awareness merely reflects a sluggish record of coordinated motor performance, while a positive value, or overshoot, suggests that participants’ intention to point to the shifting target contributes more to their awareness of action than their actual pointing movement. Undershoot and overshoot thus measure the reconstructive (motoric) and the preconstuctive (intentional) aspects of action awareness, respectively. We found that trials on which subjects strongly expected a target shift showed greater overshoot and less undershoot than trials with lower expectancy. Conscious expectancy therefore strongly influences the experience of the detailed motor parameters of our actions. Further, a delay inserted either between the expectancy judgement and the pointing movement, or between the pointing movement and the reproduction of the movement, had no effect on visuomotor adjustment but strongly influenced action awareness. Delays during either interval boosted undershoots, suggesting increased reliance on a time-limited sensory memory for action. The experience of action is thus strongly influenced by prior thoughts and expectations, but only over a short time period. Thus, awareness of our actions is a dynamic and relatively flexible mixture of what we intend to do, and what our motor system actually does. (shrink)

Obsessive-compulsive disorder is a commonly occurring neuropsychiatric condition characterized by bothersome intrusive thoughts and urges that frequently lead to repetitive dysfunctional behaviours such as excessive handwashing. There are well-documented alterations in cerebral function which appear to be closely related to the manifestation of these symptoms. Controlled studies of cognitive-behavioural therapy techniques utilizing the active refocusing of attention away from the intrusive phenomena of OCD and onto adaptive alternative activities have demonstrated both significant improvements in clinical symptoms and systematic changes in (...) the pathological brain circuitry associated with them. Careful investigation of the relationships between the experiential and putative neurophysiological processes involved in these changes can offer useful insights into volitional aspects of cerebral function. (shrink)

1. Introduction The readiness potential was found to precede voluntary acts by about half a second or more (Kornhuber & Deecke, 1965). Kornhuber (1984) discussed the readiness potential in terms of volition, arguing that it is not the manifestation of an attentional processes. Libet discussed it in relation to consciousness and to free will (Libet et al. 1983a; 1983b; Libet, 1985, 1992, 1993). Libet asked the following questions. Are voluntary acts initiated by a conscious decision to act? Are the physiological (...) facts compatible with the belief that free will determines our voluntary acts? What is the role of consciousness in voluntary action? In this paper I will discuss these questions and the answers that Libet gave to them. (shrink)

In this paper, I review the objections against the claim that brains are computers, or, to be precise, information-processing mechanisms. By showing that practically all the popular objections are either based on uncharitable interpretation of the claim, or simply wrong, I argue that the claim is likely to be true, relevant to contemporary cognitive (neuro)science, and non-trivial.

Mental causation is a predominantly theoretical topic rather than a topic studied in the laboratory. The purpose of this paper is to outline a general approach for studying mental causation by empirical means for philosophers and scientists interested in the topic. The aim is to outline how we can infer mental causation by empirical methods given an unknown solution to the mind-body problem. The approach is based on the principles of causal inference to find causal relations among observed variables used (...) in all branches of science. With these principles, it is possible to estimate the causal effects of mental events: Make an experimental manipulation of a mental event, control confounding variables, and estimate causal effects on the outcome. The caveat is that we cannot separate the causal effects of a mental event from the physical base of the mental event, independent of whether we assume mental events can be reduced to their physical base. A challenge to estimating causal effects of mental events is that measured physical variables, such as electrophysiological potentials from the brain, might reflect processes that are part of “higher-order” phenomena, such as mental events. This means that controlling “downwards” for confounding variables is challenging. It is, however, not impossible. It also means that inferring non-mental causes of action cannot be done by measuring only physical variables alone. Keeping the mind-body problem in mind when designing experiments, it is possible to infer mental causation. (shrink)

I have taken an experimental approach to this question. Freely voluntary acts are preceded by a specific electrical change in the brain that begins 550 ms before the act. Human subjects became aware of intention to act 350-400 ms after RP starts, but 200 ms. before the motor act. The volitional process is therefore initiated unconsciously. But the conscious function could still control the outcome; it can veto the act. Free will is therefore not excluded. These findings put constraints on (...) views of how free will may operate; it would not initiate a voluntary act but it could control performance of the act. The findings also affect views of guilt and responsibility. But the deeper question still remains: Are freely voluntary acts subject to macro-deterministic laws or can they appear without such constraints, non-determined by natural laws and ‘truly free'? I shall present an experimentalist view about these fundamental philosophical opposites. (shrink)

Presento la trascendencia de la neurociencia para el estudio de la relación entre determinismo y libre albedrío. Diversos trabajos vinculan la actividad de ciertas áreas nerviosas con el desempeño de las funciones volitivas, el trabajo de Benjamin Libet y de Daniel Wegner otorga gran importancia al inconsciente en nuestros actos, y hay pruebas de influencia causal del entorno sociocultural sobre el cerebro del individuo. Todo esto sugiere una concepción determinista de nuestra voluntad, pero sostengo que ni esta ni la indeterminista (...) están claras actualmente y que se debe profundizar en la neuroplasticidad, las decisiones distales y la deliberación. (shrink)