Prior to the initiation of spontaneous movement, evoked potentials can be seen to precede awareness of the impending movement by several hundreds of milliseconds, meaning that this recorded neural activity is the result of unconscious processing. This study investigates the neural representations of impending movement with and without awareness. Specifically, the relationship between awareness and ‘idling’ cortical oscillations in the beta range was assessed. It was found that, in situations where there was awareness of the impending movement, pre-movement evoked potentials (...) were associated with a decrease in beta range oscillations. In contrast, when awareness of the impending movement was not present, the onset of the pre-movement potential was associated with tonic levels of beta range oscillations. A model is considered where by distributed neural activity remains outside of conscious awareness through the persistence of tonic slow wave cortical oscillations. (shrink)

The paper begins with the assumption that psychological event tokens are identical to or constituted from physical events. It then articulates a familiar apparent problem concerning the causal role of psychological properties. If they do not reduce to physical properties, then either they must be epiphenomenal or any effects they cause must also be caused by physical properties, and hence be overdetermined. It then argues that both epiphenomenalism and over‐determinationism are prima facie perfectly reasonable and relatively unproblematic views. The paper (...) proceeds to argue against Kim’s (Kim, 2000, 2005) attempt to articulate a plausible version of reductionism. It is then argued that psychological properties, along with paradigmatically causally efficacious macro‐properties, such as toughness, are causally inefficacious in respect of their possessor’s typical effects, because they are insufficiently distinct from those effects. It is finally suggested that the distinction between epiphenomenalism and overdeterminationism may be more terminological than real. (shrink)

The paper begins with the assumption that psychological event tokens are identical to or constituted from physical events. It then articulates a familiar apparent problem concerning the causal role of psychological properties. If they do not reduce to physical properties, then either they must be epiphenomenal or any effects they cause must also be caused by physical properties, and hence be overdetermined. It then argues that both epiphenomenalism and over‐determinationism are prima facie perfectly reasonable and relatively unproblematic views. The paper (...) proceeds to argue against Kim’s (Kim, 2000, 2005) attempt to articulate a plausible version of reductionism. It is then argued that psychological properties, along with paradigmatically causally efficacious macro‐properties, such as toughness, are causally inefficacious in respect of their possessor’s typical effects, because they are insufficiently distinct from those effects. It is finally suggested that the distinction between epiphenomenalism and overdeterminationism may be more terminological than real. (shrink)

Benjamin Libet’s work paved the way for the neuroscientific study of free will. Other scientists have praised this research as groundbreaking. In philosophy, the reception has been more negative, often even dismissive. First, I will propose a diagnosis of this striking discrepancy. I will suggest that the experiments seem irrelevant, from the perspective of philosophy, due to the way in which they operationalize free will. In particular, I will argue that this operational definition does not capture free will properly and (...) that it is based on a false dichotomy between internal and external causes. However, I will also suggest that this problem could be overcome, as there are no obvious obstacles to an operationalization of free will that is in accord with the philosophical conception of free will. (shrink)

The readiness potential (RP) is one of the most controversial topics in neuroscience and philosophy due to its perceived relevance to the role of conscious willing in action. Libet and colleagues reported that RP onset precedes both volitional movement and conscious awareness of willing that movement, suggesting that the experience of conscious will may not cause volitional movement (Libet, Gleason, Wright, & Pearl, 1983). Rather, they suggested that the RP indexes unconscious processes that may actually cause both volitional movement and (...) the accompanying conscious feeling of will (Libet et al., 1983; pg. 640). Here, we demonstrate that volitional movement can occur without an accompanying feeling of will. We additionally show that the neural processes indexed by RPs are insufficient to cause the experience of conscious willing. Specifically, RPs still occur when subjects make self-timed, endogenously-initiated movements due to a post-hypnotic suggestion, without a conscious feeling of having willed those movements. (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.

Because metacognition consists in our having mental access to our cognitive states and mental states are conscious only when we are conscious of them in some suitable way, metacognition and consciousness shed important theoretical light on one another. Thus, our having metacognitive access to information carried by states that are not conscious helps con?rm the hypothesis that a mental state.

The idea is nowadays current that recent work in neurophysiology strongly counterindicates the doctrine of free will. The present piece seeks to exhibit the incorrectness of this view.

Subjects estimated the time of intentions to perform an action, of the action itself, or of an auditory effect of the action. A perceptual attraction or binding effect occurred between actions and the effects that followed them. Judgements of intentions did not show this binding, suggesting they are represented independently of actions and their effects. In additional unpredictable judgement conditions, subjects were instructed only after each trial which of these events to judge, thus discouraging focussed attention to a specific event. (...) Stronger binding effects were found, with intention, action and effect fusing to a single central point in time. In a control task, subjects reported the time of the first or second tone in sequence. Tone sequences showed no binding at all when subjects knew in advance which tone to judge, but showed the same fusion as actions when the event to be judged was not predictable. Binding of actions and effects, but not of tone sequences, occurs pre-attentively, and automatically. The data are consistent with a reconstructive process, implemented after actions, which generates a coherent sense of agency. However, this process should only be triggered only when our actions make it appropriate. We suggest that this mechanism is triggered in advance by efferent processing. This conclusion was supported by a further study in deafferented subject IW. This subject showed the normal binding of a tone towards an action, although his experience of the action was of pre-motor, rather than peripheral origin. The experience of intentional action involves an interplay between pre-motor and reconstructive processes. (shrink)

After a long period of neglect, the phenomenology of action has recently regained its place in the agenda of philosophers and scientists alike. The recent explosion of interest in the topic highlights its complexity. The purpose of this paper is to propose a conceptual framework allowing for a more precise characterization of the many facets of the phenomenology of agency, of how they are related and of their possible sources. The key assumption guiding this attempt is that the processes through (...) which the phenomenology of action is generated and the processes involved in the specification and control of action are strongly interconnected. I argue in favor of a three-tiered dynamic model of intention, link it to an expanded version of the internal model theory of action control and specification, and use this theoretical framework to guide an analysis of the contents, possible sources and temporal course of complementary aspects of the phenomenology of action. (shrink)

This paper on the phenomenology of joint agency proposes a foray into a little explored territory at the intersection of two very active domains of research: joint action and sense of agency. I explore two ways in which our experience of joint agency may differ from our experience of individual agency. First, the mechanisms of action specification and control involved in joint action are typically more complex than those present in individual actions, since it is crucial for joint action that (...) people coordinate their plans and actions. I discuss the implications that these coordination requirements might have for the strength of the sense of agency an agent may experience for a joint action. Second, engagement in joint action may involve a transformation of agentive identity and a partial or complete shift from a sense of self-agency to a sense of we-agency. I discuss several factors that may contribute to shaping our sense of agentive identity in joint action. (shrink)

This paper is concerned with the role of conscious agency in human action. On a folk-psychological view of the structure of agency, intentions, conceived as conscious mental states, are the causes of actions. In the last decades, the development of new psychological and neuroscientific methods has made conscious agency an object of empirical investigation and yielded results that challenge the received wisdom. Most famously, the results of Libet’s studies on the ‘readiness potential’ have been interpreted by many as evidence in (...) favor of a skeptical attitude towards conscious agency. It is questionable, however, whether action initiation should be regarded as the touchstone of conscious agency. I shall argue that the traditional folk-psychological view, but also some of the objections leveled against it, rest in part on an over-simplified conception of the structure of agency, that neglects both the role of control processes after action initiation and the role of planning processes before action initiation. Taking these processes into account can lead to a reassessment of the relation between intentions and action and of the role of conscious agency in action production. (shrink)

Several authors within psychology, neuroscience and philosophy take for granted that standard empirical research techniques are applicable when studying consciousness. In this article, it is discussed whether one of the key methods in cognitive neuroscience – the contrastive analysis – suffers from any serious confounding when applied to the field of consciousness studies; that is to say, if there are any systematic difficulties when studying consciousness with this method that make the results untrustworthy. Through an analysis of theoretical arguments in (...) favour of using contrastive analysis, combined with analyses of empirical findings, I conclude by arguing for three factors that currently are confounding of research using contrastive analysis. These are (1) unconscious processes, (2) introspective reports, and (3) attention. (shrink)

Despite the compelling subjective experience of executive self-control, we argue that ‘consciousness’ contains no top-down control processes. We propose that ‘consciousness’ involves no executive, causal or controlling relationship with any of the familiar psychological processes conventionally attributed to it. In our view all psychological processing and psychological products are non-conscious. In particular, we argue that all ‘contents of consciousness’ are generated by and within non-conscious brain systems in the form of a continuous self-referential personal narrative that is not directed or (...) influenced in any way by the ‘experience of consciousness’. This continuously updated personal narrative arises from selective ‘internal broadcasting’ of outputs from non-conscious executive systems that have access to all forms of cognitive processing, sensory information and motor control. The personal narrative provides information for storage in autobiographical memory and is underpinned by constructs of self and agency, also created in non-conscious systems. The experience of consciousness, is seen as a passive accompaniment to the non-conscious processes of internal broadcasting and the creation of the personal narrative. In this sense personal awareness is analogous to the rainbow which accompanies physical processes in the atmosphere but exerts no influence over them. Though at an individual level it is an end-product created by non-conscious executive systems, the personal narrative serves the powerful evolutionary function of enabling individuals to communicate (externally broadcast) the contents of internal broadcasting. This in turn allows the recipients to generate potentially adaptive strategies, such as predicting the behavior of others and underlies the development of social and cultural structures, that promote species survival. Consequently, it is the capacity to communicate to others the contents of the personal narrative that confers an evolutionary advantage – not the experience of consciousness (personal awareness) itself. (shrink)

Agentive awareness is one's awareness of oneself as presently acting. Dominant accounts in cognitive science consider agentive awareness to be grounded in the states and processes underlying sensorimotor control. In this paper, I raise concerns for this approach and develop an alternative. Broadly, in the approach I defend, one is agentively aware in the virtue of intending to act. I further argue that agentive awareness is not constituted by intentions themselves but rather first-personal thoughts that are formed on the basis (...) of them. I develop this proposal, highlight some of its theoretical advantages, and show how it successfully meets various challenges. (shrink)

Benjamin Libet's celebrated experiments concerning freedom elicited numerous attempts of _philosophical_ repudiation. Ten years ago, however, Judy Trevena and Jeff Miller published a _technical_ objection; they claim to have detected a,,smearing artifact" in Libet's calculations. This rests on a misunderstanding of Libet's methodology. In my reconstruction of Libet's argument, he draws an abductive inference to the best explanation. Now, Trevena's and Miller's objection does indeed lead to alternative explanations of Libet's measurements. These alternatives are _ad hoc_ and extremely improbable. They (...) constitute worse explanations than the explanation offered by Libet. _German_ Benjamin Libets bahnbrechende Experimente zur Willensfreiheit aus den Achtziger Jahren des vorigen Jahrhunderts gehören längst zu den Klassikern der Experimentalkunst. Aus _philosophischer_ Perspektive sind sie oft kritisiert worden; unabhängig davon ist zu Beginn des neuen Jahrtausends ein _technischer_ Einwand gegen Libet prominent geworden, der von Freiheitsfreunden gerne zitiert wird. Er geht auf Judy Trevena und Jeff Miller zurück und besteht in dem Vorwurf, dass Libet mit seiner Berechnung der _gemittelten_ Bereitschaftspotential-Kurven die wahren Verhältnisse verschmiere und dabei aus mathematischen Gründen den Anstiegs-Zeitpunkt des Bereitschaftspotentials künstlich nach vorne verschiebe – das ist der Vorwurf des sog. Verschmierungsartefakts. Ich zeige, dass der Vorwurf nicht sticht. Er beruht auf einem Missverständnis der Schlussmethode Libets. Laut meiner wissenschaftstheoretischen Rekonstruktion zieht Libet weder deduktive noch induktive Schlüsse aus seinen Einzelbeobachtungen; er schließt abduktiv, d.h. er schließt auf die beste Erklärung seiner Einzelbeobachtungen. Wie eine genaue arithmetische Analyse zeigt, bieten die Alternativ-Erklärungen, unter denen sich das Verschmierungsartefakt bewahrheiten würde, schlechtere Erklärungen als Libets Erklärung – sie sind an den Haaren herbeigezogen und extrem unwahrscheinlich. (shrink)

Four experiments examined how accurately participants can report the times of their own decisions. Within an auditory reaction time task, participants reported the time at which the tone was presented, they decided on the response, or the response key was pressed. Decision time reports were checked for plausibility against the actual RTs, and we compared the effects of experimental manipulations on these two measures to see whether the reported decision times showed appropriate effects. In addition, we estimated the amount of (...) error associated with individual decision time reports by checking how often participants’ decision time reports were implausibly early or late , and by using several quantitative models. Overall, the results suggest that decision time reports are not very accurate but they may be usable for some purposes. (shrink)

Neuroscientific studies have shown that brain activity correlated with a decision to move can be observed before a person reports being consciously aware of having made that decision . Given that a later event cannot cause an earlier one , such results have been interpreted as evidence that decisions are made unconsciously . We argue that this interpretation depends upon an all-or-none view of consciousness, and we offer an alternative interpretation of the early decision-related brain activity based on models in (...) which conscious awareness of the decision to move develops gradually up to the level of a reporting criterion. Under this interpretation, the early brain activity reflects sub-criterion levels of awareness rather than complete absence of awareness and thus does not suggest that decisions are made unconsciously. (shrink)

The idea that intentions make the difference between voluntary and non-voluntary behaviors is simple and intuitive. At the same time, we lack an understanding of how voluntary actions actually come about, and the unquestioned appeal to intentions as discrete causes of actions offers little if anything in the way of an answer. We cite evidence suggesting that the origin of actions varies depending on context and effector, and argue that actions emerge from a causal web in the brain, rather than (...) a central origin of intentional action. We argue that this causal web need not be confined to the central nervous system, and that proprioceptive feedback might play a counterintuitive role in the decision process. Finally we argue that the complex and dynamic origins of voluntary action and their interplay with the brain’s propensity to predict the immediate future are better studied using a dynamical systems approach. (shrink)

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 major findings by Libet et al. are briefly summarized. The criticisms and alternative proposals by Trevena and Miller, Pockett, and Gomes are analyzed and found to be largely unwarranted.

Developments in neurotechnology took a leap forward with the demonstration of the first Brain to Brain Interface (BBI). BBIs enable direct communication between two brains via a Brain Computer Interface (BCI) and bypasses the peripheral nervous system. This discovery promises new possibilities for future battlefield technology. As battlefield technology evolves, it is more likely to place greater demands on future soldiers. Future soldiers are more likely to process large amounts of data derived from an extensive networks of humans and machines. (...) This raises several ethical and philosophical concerns. This paper will look at BBI technology in current stages of research, future BBI applications in the military and how the potential use of BBIs in military operations challenges the way we understand the concept of responsibility. In this paper, I propose that an individual connected to a BBI ought not to be held fully responsible for her actions. The justification for this proposition is based on three key points such as an individual connected to a BBI does not have the ability to act freely, has a diminished sense of self-agency and may not be able to demonstrate authenticity of the thoughts and memories generated when connected to the interface. (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)

Consciousness as used here, refers to the private, subjective experience of being aware of our perceptions, thoughts, feelings, actions, memories including the intimate experience of a unified self with the capacity to generate and control actions and psychological contents. This compelling, intuitive consciousness-centric account has, and continues to shape folk and scientific accounts of psychology and human behavior. Over the last 30 years, research from the cognitive neurosciences has challenged this intuitive social construct account when providing a neurocognitive architecture for (...) a human psychology. Growing evidence suggests that the executive functions typically attributed to the experience of consciousness are carried out competently, backstage and outside subjective awareness by a myriad of fast, efficient non-conscious brain systems. While it remains unclear how and where the experience of consciousness is generated in the brain, we suggested that the traditional intuitive explanation that consciousness is causally efficacious is wrong-headed when providing a cognitive neuroscientific account of human psychology. Notwithstanding the compelling 1st-person experience that convinces us that subjective awareness is the mental curator of our actions and thoughts, we argue that the best framework for building a scientific account is to be consistent with the biophysical causal dependency of prior neural processes. From a 3rd person perspective,, we propose that subjective awareness lacking causal influence, is than our experience of being aware, our awareness of our psychological content, knowing that we are aware, and the belief that that such experiences are evidence of an agentive capacity shared by others. While the human mind can be described as comprising both conscious and nonconscious aspects, both ultimately depend on neural process in the brain. In arguing for the counter-intuitive epiphenomenal perspective, we suggest that a scientific approach considers all mental aspects of mind including consciousness in terms of their underlying, preceding biological changes, in the realization that most brain processes are not accompanied by any discernible change in subjective awareness. (shrink)

We explored the neural mechanisms allowing humans to report the subjective onset times of conscious events. Magnetoencephalographic recordings of neural oscillations were obtained while human subjects introspected the timing of sensory, intentional, and motor events during a forced choice task. Brain activity was reconstructed with high spatio-temporal resolution. Event-time introspection was associated with specific neural activity at the time of subjective event onset which was spatially distinct from activity induced by the event itself. Different brain regions were selectively recruited for (...) introspection of different event types, e.g., the bilateral angular gyrus for introspection of intention. Our results suggest that event-time introspection engages specific neural networks to assess the contents of consciousness. Subjective event times should therefore be interpreted as the result of complex interactions between introspection and experience networks, rather than as direct reproduction of the individual’s conscious state or as a mere post hoc interpretation. (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)

Contemporary experimental research has emphasised the role of centrally generated signals arising from premotor areas in voluntary muscular force perception. It is therefore generally accepted that judgements of force are based on a central sense, known as the sense of effort, rather than on a sense of intra-muscular tension. Interestingly, the concept of effort is also present in the classical philosophy: to the French philosopher Maine de Biran [Maine de Biran . Mémoire sur la décomposition de la pensée , Vrin, (...) Paris ], the sense of effort is the fundamental component of self-experience, the landmark of the exercise of the will. In the present review, after a presentation of the nature and neurophysiological bases of effort sensation, we will examine its possible involvement in the neurocognitive process of agency. We will further focus on delusions of alien control in schizophrenic patients. Experimental data suggest that these patients have an abnormal awareness of effort caused by cerebral anomalies in the frontal and parietal lobes. (shrink)

In recent years there has been some hard-won but still limited agreement that phenomenology can be of central and positive importance to the cognitive sciences. This realization comes in the wake of dismissive gestures made by philosophers of mind who mistakenly associate phenomenological method with untrained psychological introspection (e.g., Dennett 1991). For very different reasons, resistance is also found on the phenomenological side of this issue. There are many thinkers well versed in the Husserlian tradition who are not willing to (...) consider the validity of a naturalistic science of mind. For them cognitive science is too computational or too reductionistic to be seriously considered as capable of explaining experience or consciousness. In some cases, when phenomenologists have seriously engaged the project of the cognitive sciences, rather than pursing a positive rapprochement with this project, they have been satisfied in drawing critical lines that identify its limitations.On the one hand, such negative attitudes are understandable from the perspective of the Husserlian rejection of naturalism, or from strong emphasis on the transcendental current in phenomenology. (shrink)

Although philosophical approaches to the self are diverse, several of them are relevant to cognitive science. First, the notion of a 'minimal self', a self devoid of temporal extension, is clarified by distinguishing between a sense of agency and a sense of ownership for action. To the extent that these senses are subject to failure in pathologies like schizophrenia, a neuropsychological model of schizophrenia may help to clarify the nature of the minimal self and its neurological underpinnings. Second, there is (...) good evidence to suggest that although certain aspects of the minimal self are primitive and embodied, other aspects may be accessed only in reflective consciousness. Employing a modified concept of the minimal self, it may be possible to construct a robotic form of non-conscious self-reference that depends on an interaction between the robotic body and its environment. In contrast to the minimal self, the narrative self involves continuity over time and is directly relevant to discussions of memory and personal identity. There is growing consensus among philosophers and cognitive scientists about the importance of narrative and its relation to episodic memory and left-hemisphere functions. There are, however, at least two different views of how the narrative self is structured. On one model it is nothing more than an abstract point. On a more extended view, proposed here, the self is a rich amalgam of narratives that allows for the equivocations, contradictions, and self-deceptions of personal life. Even in this case, however, neurocognitive models contribute to our understanding of how narrative identity is structured. (shrink)

Patients with delusions of control are abnormally aware of the sensory consequences of their actions and have difficulty with on-line corrections of movement. As a result they do not feel in control of their movements. At the same time they are strongly aware of the action being intentional. This leads them to believe that their actions are being controlled by an external agent. In contrast, the normal mark of the self in action is that we have very little experience of (...) it. Most of the time we are not aware of the sensory consequences of our actions or of the various subtle corrections that we make during the course of goal-directed actions. We know that we are agents and that we are successfully causing the world to change. But as actors we move through the world like shadows glimpsed only occasional from the corner of an eye. (shrink)

The paper investigates possible readings of the later Heisenberg's remarks on the nature of quantum states. It discusses, in particular, whether Heisenberg should be seen as a proponent of the epistemic conception of states – the view that quantum states are not descriptions of quantum systems but rather reflect the state assigning observers' epistemic relations to these systems. On the one hand, it seems plausible that Heisenberg subscribes to that view, given how he defends the notorious "collapse of the wave (...) function" by relating it to a sudden change in the epistemic situation of the observer registering a measured result. On the other hand, his remarks on quantum probabilities as "potentia" or "objective tendencies" are difficult to reconcile with such a reading. The accounts that are attributed to Heisenberg by the different possible readings considered are subjected to closer scrutiny; at the same time, their respective virtues and problems are discussed. _German_ Diese Arbeit untersucht mögliche Lesarten von Heisenbergs späten Bemerkungen über die Natur von Quantenzuständen. Insbesondere wird die Frage diskutiert, ob Heisenberg als Vertreter der epistemischen Auffassung von Quantenzuständen gelten kann – der Idee, dass Quantenzustände nicht Beschreibungen der objektiven Eigenschaften von Quantensystemen sind sondern die epistemischen Beziehungen von Beobachtern zu diesen Systemen widerspiegeln. Einerseits erscheint es plausibel, dass Heisenberg dieser Sichtweise zustimmt, wenn man sich ansieht, wie er den berüchtigten,,Kollaps der Wellenfunktion" verteidigt, indem er ihn mit einer plötzlichen Änderung in der Kenntnis des ein Messergebnis registrierenden Beobachters in Zusammenhang bringt. Andererseits sind seine Bemerkungen über quantenmechanische Wahrscheinlichkeiten als,,Potentia" oder,,objektive Tendenzen" mit einer solchen Lesart nur schwer in Einklang zu bringen. Die Positionen, die Heisenberg den verschiedenen möglichen Lesarten zufolge vertritt, werden eingehenden Untersuchungen unterzogen; gleichzeitig werden ihre jeweiligen Vorzüge und Probleme diskutiert. (shrink)