Sixty Years After Orne's American Psychologist Article: A Conceptual Framework for Subjective Experiences Elicited by Demand Characteristics.

Study participants form beliefs based on cues present in a testing situation (demand characteristics). These beliefs can alter study outcomes (demand effects). Neglecting demand effects can threaten the internal and external validity of studies (including their replication). While demand characteristics garnered much attention following Orne's introduction of this notion, consideration of their effects has become sparse in experimental reports. Moreover, the concept remains confusing. Here, we introduce a conceptual framework for subjective experiences elicited by demand characteristics. The model distinguishes between participants' awareness of the hypothesis, their motivation to comply with it, and the strategy they use to meet situational requirements. We stress that demand characteristics can give rise to genuine experiences. To illustrate, we apply the model to Evaluative Conditioning and the Rubber Hand Illusion. In the General Discussion, we discuss risks and opportunities associated with demand characteristics, and we explain that they remain highly relevant to current research.

Effect of alcohol on the sense of agency in healthy humans.

Even at low to moderate doses, ingestion of the widely used recreational drug alcohol (ethanol) can impact cognitive and emotional processing. Recent studies show that the sense of agency (SoA; ie, the subjective experience of voluntary control over actions) can be modulated by specific pharmacological manipulations. The SoA, as quantified by the intentional binding (IB) paradigm, is enhanced by direct or indirect dopaminergic agonists in patients with Parkinson's disease and by ketamine (an N-methyl-D-aspartate (NMDA) receptor antagonist) in healthy individuals. These findings implicate dopaminergic and glutamatergic neurotransmission in mechanisms underlying SoA. Alcohol has a complex set of actions, including disinhibition of dopaminergic neurotransmission and allosteric antagonism at NMDA receptors. Here, we tested the hypothesis that low to moderate doses of alcohol would enhance SoA, and impact impulsivity and subjective emotional state. We conducted two experiments in 59 healthy male and female social drinkers, who ingested either a placebo "vehicle," or one of two doses of ethanol: 0.4 and 0.6 g/kg. In both experiments, we observed increased SoA/IB at both doses of alcohol exposure, relative to the placebo condition. We found no correlation between the effects of alcohol on IB and on impulsivity or subjective emotional state. Our findings might have implications for social and legal responsibility related to alcohol use, particularly in states prior to overt intoxication. Further studies are necessary to investigate the effects of alcohol and other addictive substances on the SoA.

Intentional Binding Without Intentional Action.

The experience of authorship over one's actions and their consequences-sense of agency-is a fundamental aspect of conscious experience. In recent years, it has become common to use intentional binding as an implicit measure of the sense of agency. However, it remains contentious whether reported intentional-binding effects indicate the role of intention-related information in perception or merely represent a strong case of multisensory causal binding. Here, we used a novel virtual-reality setup to demonstrate identical magnitude-binding effects in both the presence and complete absence of intentional action, when perceptual stimuli were matched for temporal and spatial information. Our results demonstrate that intentional-binding-like effects are most simply accounted for by multisensory causal binding without necessarily being related to intention or agency. Future studies that relate binding effects to agency must provide evidence for effects beyond that expected for multisensory causal binding by itself.

The Power of Suggestion: Posthypnotically Induced Changes in the Temporal Binding of Intentional Action Outcomes.

The sense of agency is the experience of initiating and controlling one's voluntary actions and their outcomes. Intentional binding (i.e., when voluntary actions and their outcomes are perceived to occur closer together in time than involuntary actions and their outcomes) is increased in intentional action but requires no explicit reflection on agency. The reported experience of involuntariness is central to hypnotic responding, during which strategic action is experienced as involuntary. We report reduced intentional binding in a hypnotically induced experience of involuntariness, providing an objective correlate of reports of involuntariness. We argue that this reduced binding results from the diminished influence of motor intentions in the generation of the sense of agency when beliefs about whether an action is intended are altered. Thus, intentional binding depends on awareness of intentions. This finding shows that changes in metacognition of intentions affect perception.

Beware 'persuasive communication devices' when writing and reading scientific articles.

Authors rely on a range of devices and techniques to attract and maintain the interest of readers, and to convince them of the merits of the author's point of view. However, when writing a scientific article, authors must use these 'persuasive communication devices' carefully. In particular, they must be explicit about the limitations of their work, avoid obfuscation, and resist the temptation to oversell their results. Here we discuss a list of persuasive communication devices and we encourage authors, as well as reviewers and editors, to think carefully about their use.

Time perception and the experience of agency in meditation and hypnosis.

Mindfulness meditation and hypnosis are related in opposing ways to awareness of intentions. The cold control theory of hypnosis proposes that hypnotic responding involves the experience of involuntariness while performing an actually intentional action. Hypnosis therefore relies upon inaccurate metacognition about intentional actions and experiences. Mindfulness meditation centrally involves awareness of intentions and is associated with improved metacognitive access to intentions. Therefore, mindfulness meditators and highly hypnotizable people may lie at opposite ends of a spectrum with regard to metacognitive access to intention-related information. Here we review the theoretical background and evidence for differences in the metacognition of intentions in these groups, as revealed by chronometric measures of the awareness of voluntary action: the timing of an intention to move (Libet's "W" judgments) and the compressed perception of time between an intentional action and its outcome ("intentional binding"). We review these measures and critically evaluate their proposed connection to the experience of volition and sense of agency.

Intentional binding as Bayesian cue combination: Testing predictions with trait individual differences.

We investigated differences in intentional binding in high and low hypnotizable groups to explore two questions relating to (a) trait differences in the availability of motor intentions to metacognitive processes and (b) a proposed cue combination model of binding. An experience of involuntariness is central to hypnotic responding and may arise from strategically being unaware of one's intentions. Trait differences in the ability to respond to hypnotic suggestion may reflect differing levels of access to motor intentions. Intentional binding refers to the subjective compression of the time between an action and its outcome, indicated by a forward shift in the judged time of an action toward its outcome (action binding) and the backward shift of an outcome toward a causal action (outcome binding). Intentional binding is sensitive to intentional action without requiring explicit reflection upon agency. One way of explaining the sensitivity of intentional binding is to see it as a simple case of multisensory cue combination in which awareness of intentions increases knowledge of the timing of actions. Here we present results consistent with such a mechanism. In a contingent presentation of action and outcome events, low hypnotizable had more precise timing judgments of actions and also showed weaker action binding than highs. These results support the theory that trait hypnotizability is related to access to information related to motor intentions, and that intentional binding reflects the Bayesian combination of cross-modal cues. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Metacognition of intentions in mindfulness and hypnosis.

In a famous series of experiments, Libet investigated the subjective timing of awareness of an intention to move, a task that can be considered a metacognitive judgement. The ability to strategically produce inaccurate metacognitions about intentions has been postulated to be central to the changes in judgements of agency common to all hypnotic responding. Therefore, differences in hypnotisability may be reflected in Libet's measure. Specifically, the ability to sustain inaccurate judgements of agency displayed by highly hypnotisable people may result from their having coarser higher order representations of intentions. They, therefore, should report a delayed time of intention relative to less hypnotisable individuals. Conversely, mindfulness practice aims at accurate metacognition, including of intentions, and may lead to the development of finer grained higher order representations of intending. Thus, the long-term practice of mindfulness may produce an earlier judgement of the time of an intention. We tested these groups using Libet's task, and found that, consistent with predictions, highly hypnotisable people reported a later time of intention than less hypnotisable people and meditators an earlier time than non-meditators. In a further two studies, we replicated the finding that hypnotisable people report later awareness of a motor intention and additionally found a negative relationship between trait mindfulness and this measure. Based on these findings, we argue that hypnotic response and meditation involve opposite processes.

Illusory Temporal Binding in Meditators.

We investigate conditions in which more accurate metacognition may lead to greater susceptibility to illusion and thus conditions under which mindfulness meditation may lead to less accurate perceptions. Specifically, greater awareness of intentions may lead to an illusory compression of time between a voluntary action and its outcome ("intentional binding"). Here, we report that experienced Buddhist mindfulness meditators rather than non-meditators display a greater illusory shift of the timing of an outcome toward an intentional action. Mindfulness meditation involves awareness of causal connections between different mental states, including intentions. We argue that this supports improvements in metacognition targeted at motor intentions. Changes in metacognitive ability may result in an earlier and less veridical experience of the timing of action outcomes either through increased access to sensorimotor pre-representations of an action outcome or by affording greater precision to action timing judgements. Furthermore, as intentional binding is an implicit measure of the sense of agency; these results also provide evidence that mindfulness meditators experience a stronger sense of agency.