The Unconscious Experimentally Demonstrated by Means of Hypnosis

Activitas Nervosa Superior, 2016

The question of how to define and explain hypnosis is still not completely answered. Most of the theories of hypnosis are based on describing it as an altered state of consciousness; others focus on intrapersonal and interpersonal aspects, sociopsychological, neurocognitive or sociocognitive processes. More detailed explanation of hypnosis requires a synthesis of these various perspectives — a task for future research. Recent experiments are in agreement with Braid’s concept of hypnosis (published already in 1843) defining hypnosis as a process enhancing or depressing neural activity as well as changing functional connectivity among brain regions; the brain regions involved in mental imagery are thought to be central for hypnosis. In the present article we suggest that the “hidden observer” under hypnosis might be due to the cognitive unconscious and that this special state emerges principally in highly susceptible subjects. Explicitly, the “hidden observer” might be nothing other t...

Contemporary Hypnosis, 1998

Neuropsychophysiological evidence is reviewed testing a three-stage, top-down working model of the traditional hypnotic relaxation induction involving: (1) a thalamocortical attentional network engaging a left frontolimbic focused attention control system underpinning sensory fixation and concentration on the induction; (2) instatement of frontolimbic inhibitory systems through suggestions of tiredness at fixation and relaxation whereby anterior executive functions are suspended and directed by the induction; (3) engagement of right-sided temporoposterior functions through passive imagery and dreaming. A selectivity of action in high susceptibles was a hallmark of the studies. Increased Stroop interference coincided with maintenance of error detection and abolition of error evaluation potentials, interpreted as dissociation of cognitive and affective executive systems of the anterior cingulate. Verbal, category and design fluency tasks were dissociated with hypnosis centring on left anterior processes as seen in left lateral and medial reduced EEG connectivity. Limbic modulated electrodermal orienting responses and frontal modulated mismatch negativity waves were inhibited. Asymmetries in electrodermal and electrocortical responses to tones shifted to favour the right hemisphere, an asymmetry also seen in visual sensitivity. Haptic processing and visual sensitivity disclosed more distributed changes in medium susceptibles, while low susceptibles were characterized by poorer attentional functions at baseline and improvements through the induction.

Neurophysiologie Clinique/Clinical Neurophysiology, 2013

We here review behavioral, neuroimaging and electrophysiological studies of hypnosis as a state, as well as hypnosis as a tool to modulate brain responses to painful stimulations. Studies have shown that hypnotic processes modify internal (self awareness) as well as external (environmental awareness) brain networks. Brain mechanisms underlying the modulation of pain perception under hypnotic conditions involve cortical as well as subcortical areas including anterior cingulate and prefrontal cortices, basal ganglia and thalami. Combined with local anesthesia and conscious sedation in patients undergoing surgery, hypnosis is associated with improved periand postoperative comfort of patients and surgeons. Finally, hypnosis can be considered as a useful analogue for simulating conversion and dissociation symptoms in healthy subjects, permitting better characterization of these challenging disorders by producing clinically similar experiences.

Cortex, 2013

Keywords: Hypnosis Functional connectivity Hypnotizability Neurophenomenology EEG a b s t r a c t Introduction: After a hypnotic induction, medium and highly hypnotizable individuals often report spontaneous alterations in various dimensions of consciousness. Few studies investigating these experiences have controlled for the inherent demands of specific hypnotic suggestions and fewer still have considered their dynamic properties and neural correlates.

The main objective of this study was to compare the neurophenomenology of the Out-of-Body-Experience (OBE) state induced by hypnotic suggestion on a group of five selected participants with other states of consciousness, specifically the state of imagined OBE and hypnosis. From a phenomenological point of view, a comparison of the OBE state with that of deep hypnosis, measured by using the Phenomenology of Consciousness Inventory, gave higher scores of Self-Awareness, Memory, Rationality, Voluntary Control and Imagery for the OBE. From a neurophysiological perspective, the major difference – with respect to all other control conditions – was an increase in the power spectrum density and a decrease of coherence of the delta band when participants were required to answer questions posed by the hypnotist during their OBE state, suggesting that this could be the neurophysiological marker of this special state of consciousness.

2007

Consciousness and Cognition, 2011

Research in cognitive neuroscience now considers the state of the brain prior to the task an important aspect of performance. Hypnosis seems to alter the brain state in a way which allows external input to dominate over internal goals. We examine how normal development may illuminate the hypnotic state. In their paper designed to relate research on hypnosis to neuroscience Raz and Shapiro (2002) say: "Historically, hypnosis was defined as an altered state of consciousness, characterized by heightened compliance with suggestion and extreme focused attention. Whereas this definition presumes a specific theoretical view, over the years this characterization of hypnosis was gradually refined and amended to reflect a more theoretically neutral approach. Nonetheless, one persistent barrier to the scientific use of hypnosis has been the idea that it involves a special and "mysterious" state of consciousness, often referred to as trance." Page 85 Recently there has been great interest in cognitive neuroscience in the specification of brain states. Throughout the history of brain research there has been competition between an emphasis on intrinsic brain activity and stimulation from sensory input. The discovery, following World War II, of the reticular activating system (Moruzzi & Magoun, 1949) turned attention to sleep wake cycles, and arousal functions and led to the discoveries of a number of neuro modulatory systems.

Neuroscience of Consciousness

This article summarizes key advances in hypnosis research during the past two decades, including (i) clinical research supporting the efficacy of hypnosis for managing a number of clinical symptoms and conditions, (ii) research supporting the role of various divisions in the anterior cingulate and prefrontal cortices in hypnotic responding, and (iii) an emerging finding that high hypnotic suggestibility is associated with atypical brain connectivity profiles. Key recommendations for a research agenda for the next decade include the recommendations that (i) laboratory hypnosis researchers should strongly consider how they assess hypnotic suggestibility in their studies, (ii) inclusion of study participants who score in the middle range of hypnotic suggestibility, and (iii) use of expanding research designs that more clearly delineate the roles of inductions and specific suggestions. Finally, we make two specific suggestions for helping to move the field forward including (i) the use of data sharing and (ii) redirecting resources away from contrasting state and nonstate positions toward studying (a) the efficacy of hypnotic treatments for clinical conditions influenced by central nervous system processes and (b) the neurophysiological underpinnings of

The subliminal activation of an hypnotic response and the subliminal activation of a posthypnotic response were tested within subject, with the order of testing counterbalanced across subjects. Eight hypnotized subjects of high hypnotizability, eight hypnotized subjects of lesser hypnotizability, eight hypnotic simulators of high hypnotizability, and eight hypnotic simulators of lesser hypnotizability were tested. The results indicate that stimulus-elicited responses can be elicited subliminally during deep hypnosis, because deeply hypnotized subjects are able to recognize critical subliminal stimuli. The results also indicate that posthypnotic responses can only be elicited supraliminally, except when previous hypnotic recognition of subliminal stimuli enables subjects to expect and to abstract similar subliminal stimuli posthypnotically.

Contemporary Hypnosis, 2009

This short review describes recent advances in understanding hypnotic modulation of pain. Our current understanding of pain perception is followed by a critical review of the hypnotic analgesia studies using EEG, evoked potential and functional imaging methodologies.