Our sense of self includes awareness of our thoughts and movements, and our control over them. This feeling can be altered or lost in neuropsychiatric disorders as well as in phenomena such as “automatic writing” whereby writing is attributed to an external source. Here, we employed suggestion in highly hypnotically suggestible participants to model various experiences of automatic writing during a sentence completion task. Results showed that the induction of hypnosis, without additional suggestion, was associated with a small but significant (...) reduction of control, ownership, and awareness for writing. Targeted suggestions produced a double dissociation between thought and movement components of writing, for both feelings of control and ownership, and additionally, reduced awareness of writing. Overall, suggestion produced selective alterations in the control, ownership, and awareness of thought and motor components of writing, thus enabling key aspects of automatic writing, observed across different clinical and cultural settings, to be modelled. (shrink)

The comparator-model, originally developed to explain motor action, has recently been invoked to explain several aspects of the self. However, in the first place it may not be used to explain a basic self-world distinction because it presupposes one. Our alternative account is based on specific systematic covariation between action and perception. Secondly, the comparator model cannot explain the feeling of ownership of thoughts. We argue—contra Frith and Campbell—that thoughts are not motor processes and therefore cannot be described by the (...) comparator-model. Rather, thoughts can be the triggering cause (intention) for actions. An alternative framework for the explanation of thought insertion in schizophrenics is presented. (shrink)

People experiencing alien control report that their thoughts, movements, actions, and emotions have been replaced by those of an "other." The latter is commonly a perceived persecutor of the patient. Here I describe the clinical phenomenology of alien control, mechanistic models that have been used to explain it, problems inherent in these models, the brain deficits and functional abnormalities associated with this symptom, and the means by which disordered agency may be examined in this perplexing condition. Our current state of (...) knowledge implicates potentially reversible dysfunction in certain key brain regions (especially the right parietal cortex), which is temporally related to the presence of symptoms. Alien control is quintessentially a disorder of agency. (shrink)

Using the Stroop paradigm, we have previously shown that a specific suggestion can remove or reduce involuntary conflict and alter information processing in highly suggestible individuals . In the present study, we carefully matched less suggestible individuals to HSIs on a number of factors. We hypothesized that suggestion would influence HSIs more than LSIs and reduce the Stroop effect in the former group. As well, we conducted secondary post hoc analyses to examine negative priming – the apparent disruption of the (...) response to a previously-ignored item. Our present findings indicate that suggestion reduces Stroop effects in HSIs. Secondary analyses show that LSIs had an NP effect at baseline and that suggestion influenced the NP condition. Thus, at least in this experimental context, suggestion seems to dampen a deeply-engrained and largely automatic process – reading – by wielding a larger influence on HSIs relative to comparable LSIs. (shrink)

Two experiments report on the construction of the Sense of Agency Rating Scale (SOARS), a new measure for quantifying alterations to agency. In Experiment 1, 370 participants completed a preliminary version of the scale following hypnosis. Factor analysis revealed two underlying factors: Involuntariness and Effortlessness. In Experiment 2, this two factor structure was confirmed in a sample of 113 low, medium and high hypnotisable participants. The two factors, Involuntariness and Effortlessness, correlated significantly with hypnotisability and pass rates for ideomotor, challenge (...) and cognitive items. Twelve week test-retest correlations showed that Involuntariness was highly stable, but Effortlessness only moderately stable. Analysis of the combined datasets from Experiments 1 and 2 showed both SOARS scores were significantly related to the derived factors of Woody, Barnier, and McConkey's (2005) 4-factor model of hypnotisability. This scale clarifies conceptual confusion around agentive action and provides empirical support for a multifactorial account of sense of agency. (shrink)

have recently provided a compelling demonstration of enhanced attentional control under post-hypnotic suggestion. Using the classic color-word interference paradigm, in which the task is to ignore a word and to name the color in which it is printed (e.g., RED in green, say ''green''), they gave a post-hypnotic instruction to participants that they would be unable to read. This eliminated Stroop interference in high suggestibility participants but did not alter interference in low suggestibility participants. replicated this pattern and further demonstrated (...) that it is not due to a visual strategy (such as blurring or looking at a different location). As a historical footnote, we describe a ''case study'' from 18 years ago in which we observed the same result using a hypnotic instruction to a single highly suggestible individual that he could not read. The elimination of Stroop interference has important implications for both the study of attention and the study of hypnosis. (shrink)

Disparate theoretical viewpoints construe hypnotic suggestibility either as a stable trait, largely determined by underlying cognitive aptitude, or as a flexible skill amenable to attitudinal factors including beliefs and expectations. Circumscribed findings support both views. The present study attempted to consolidate these orthogonal perspectives through the lens of expectancy modification. We surreptitiously controlled light and sound stimuli to convince participants that they were responding strongly to hypnotic suggestions for visual and auditory hallucinations. Extending our previous findings, we indexed hypnotic suggestibility (...) by de-automatizing an involuntary audiovisual phenomenon—the McGurk effect. Here we show that, regardless of expectancy modification, the experimental procedure led to heightened expectations concerning future hypnotic response. We found little effect of expectation, however, on actual response to suggestion. Our findings intimate that, at least in the present experimental context, expectation hardly correlates with—and is unlikely to be a primary determinant of—high hypnotic suggestibility. (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 abilities to attribute an action to its proper agent and to understand its meaning when it is produced by someone else are basic aspects of human social communication. Several psychiatric syndromes, such as schizophrenia, seem to lead to a dysfunction of the awareness of one’s own action as well as of recognition of actions performed by other. Such syndromes offer a framework for studying the determinants of agency, the ability to correctly attribute actions to their veridical source. Thirty normal (...) subjects and 30 schizophrenic patients with and without hallucinations and/or delusional experiences were required to execute simple finger and wrist movements, without direct visual control of their hand. The image of either their own hand or an alien hand executing the same or a different movement was presented on a TV-screen in real time. The task for the subjects was to discriminate whether the hand presented on the screen was their own or not. Hallucinating and deluded schizophrenic patients were more impaired in discriminating their own hand from the alien one than the non-hallucinating ones, and tended to misattribute the alien hand to themselves. Results are discussed according to a model of action control. A tentative description of the mechanisms leading to action consciousness is proposed. (shrink)

Philosophers are interested in the phenomenon of thought insertion because it challenges the common assumption that one can ascribe to oneself the thoughts that one can access first-personally. In the standard philosophical analysis of thought insertion, the subject owns the ‘inserted’ thought but lacks a sense of agency towards it. In this paper we want to provide an alternative analysis of the condition, according to which subjects typically lack both ownership and authorship of the ‘inserted’ thoughts. We argue that by (...) appealing to a failure of ownership and authorship we can describe more accurately the phenomenology of thought insertion, and distinguish it from that of non-delusional beliefs that have not been deliberated about, and of other delusions of passivity. We can also start developing a more psychologically realistic account of the relation between intentionality, rationality and self knowledge in normal and abnormal cognition. (shrink)

Cognitive scientists distinguish between automatic and controlled mental processes. Automatic processes are either innately involuntary or become automatized through extensive practice. For example, reading words is a purportedly automatic process for proficient readers and the Stroop effect is consequently considered the “gold standard” of automated performance. Although the question of whether it is possible to regain control over an automatic process is mostly unasked, we provide compelling data showing that posthypnotic suggestion reduced and even removed Stroop interference in highly hypnotizable (...) individuals. Drawing on a large sample of highly hypnotizable participants, we examined the effects of suggestion on Stroop performance both with and without a posthypnotic suggestion to perceive the input stream as meaningless symbols. We show that suggestion administered to highly hypnotizable persons significantly reduced Stroop interference and derailed a seemingly automatic process. (shrink)