Evaluation of putative signatures of consciousness using specific definitions of responsiveness, connectedness, and consciousness.

BACKGROUND: Understanding the neural correlates of consciousness has important ramifications for the theoretical understanding of consciousness and for clinical anaesthesia. A major limitation of prior studies is the use of responsiveness as an index of consciousness. We identified a collection of measures derived from unresponsive subjects and more specifically their association with consciousness (any subjective experience) or connectedness (specific experience of environmental stimuli). METHODS: Using published data generated through the UNderstanding Consciousness Connectedness and Intra-Operative Unresponsiveness Study (NCT03284307), we evaluated 10 previously published resting-state EEG-based measures that were derived using unresponsiveness as a proxy for unconsciousness. Measures were tested across dexmedetomidine and propofol sedation and natural sleep. These markers represent the complexity, connectivity, cross-frequency coupling, graph theory, and power spectrum measures. RESULTS: Although many of the proposed markers were associated with consciousness per se (reported subjective experience), none were specific to consciousness alone; rather, each was also associated with connectedness (i.e. awareness of the environment). In addition, multiple markers showed no association with consciousness and were associated only with connectedness. Of the markers tested, loss of normalised-symbolic transfer entropy (front to back) was associated with connectedness across all three experimental conditions, whereas the transition from disconnected consciousness to unconsciousness was associated with significant decreases in permutation entropy and spectral exponent (P<0.05 for all conditions). CONCLUSIONS: None of the proposed EEG-based neural correlates of unresponsiveness corresponded solely to consciousness, highlighting the need for a more conservative use of the term (un)consciousness when assessing unresponsive participants. CLINICAL TRIAL REGISTRATION: NCT03284307.

Efficacy of the Alexander Technique in treating chronic non-specific neck pain: a randomized controlled trial.

OBJECTIVE: To test the efficacy of the Alexander Technique, local heat and guided imagery on pain and quality of life in patients with chronic non-specific neck pain. DESIGN: A randomized controlled trial with 3 parallel groups was conducted. SETTING: Outpatient clinic, Department of Internal and Integrative Medicine. SUBJECTS: A total of 72 patients (65 females, 40.7±7.9 years) with chronic non-specific neck pain. INTERVENTIONS: Patients received 5 sessions of the Alexander Technique--an educational method which aims to modify dysfunctional posture, movement and thinking patterns associated with musculoskeletal disorders. Control groups were treated with local heat application or guided imagery. All interventions were conducted once a week for 45 minutes each. MAIN MEASURES: The primary outcome measure at week 5 was neck pain intensity on a 100-mm visual analogue scale; secondary outcomes included neck disability, quality of life, satisfaction and safety. STATISTICS: Analyses of covariance were applied; testing ordered hypotheses. RESULTS: No group difference was found for pain intensity for the Alexander Technique compared to local heat (difference 4.5mm; 95% CI:-8.1;17.1; p=0.48), but exploratory analysis revealed the superiority of the Alexander Technique over guided imagery (difference -12.9 mm; 95% CI:-22.6;-3.1, p=0.01). Significant group differences in favor of the Alexander Technique were also found for physical quality of life (P<0.05). Adverse events mainly included slightly increased pain and muscle soreness. CONCLUSION: The Alexander Technique was not superior to local heat application in treating chronic non-specific neck pain. It cannot be recommended as routine intervention at this time. Further trials are warranted for conclusive judgment.

Toward a phenomenology of inner speaking.

Inner speaking is a common and widely discussed phenomenon of inner experience. Based on our studies of inner experience using Descriptive Experience Sampling (a qualitative method designed to produce high fidelity descriptions of randomly selected pristine inner experience), we advance an initial phenomenology of inner speaking. Inner speaking does occur in many, though certainly not all, moments of pristine inner experience. Most commonly it is experienced by the person as speaking in his or her own naturally inflected voice but with no sound being produced. In addition to prototypical instances of inner speaking, there are wide-ranging variations that fit the broad category of inner speaking and large individual differences in the frequency with which individuals experience inner speaking. Our observations are discrepant from what many have said about inner speaking, which we attribute to the characteristics of the methods different researchers have used to examine inner speaking.

The vision of haptics tunes the somatosensory threshold.

The interaction between different sensory modalities represents a crucial issue in the neuroscience of consciousness: when the processing of one modality is deficient, the concomitant presentation of stimuli of other spared modalities may sustain the restoration of the damaged sensory functions. In this regard, visual enhancement of touch may represent a viable tool in rehabilitating tactile disorders, yet the specific visual features mostly modulating the somatosensory experience remain unsettled. In this study, healthy subjects underwent a tactile detection task during the observation of videos displaying different contents, including static gratings, meaningless motions and natural or point-lights reach-to-grasp-and-manipulate actions. Concurrently, near-threshold stimuli were delivered to the median nerve at different time-points. The subjective report was collected after each trial; the sensory detection rate was computed and compared across video conditions. Our results indicate that the specific presence of haptic contents (i.e., the vision of manipulation), either fully displayed or implied by point-lights, magnifies tactile sensitivity. The notion that such stimuli prompt a conscious tactile experience opens to novel rehabilitation approaches for tactile consciousness disorders.

Measuring the Frequency of Inner-Experience Characteristics by Self-Report: The Nevada Inner Experience Questionnaire.

Descriptive experience sampling has suggested that there are five frequently occurring phenomena of inner experience: inner speaking, inner seeing, unsymbolized thinking, feelings, and sensory awareness. Descriptive experience sampling is a labor- and skill-intensive procedure, so it would be desirable to estimate the frequency of these phenomena by questionnaire. However, appropriate questionnaires either do not exist or have substantial limitations. We therefore created the Nevada Inner Experience Questionnaire (NIEQ), with five subscales estimating the frequency of each of the frequent phenomena, and examine here its psychometric adequacy. Exploratory factor analysis produced four of the expected factors (inner speaking, inner seeing, unsymbolized thinking, feelings) but did not produce a sensory awareness factor. Confirmatory factor analysis validated the five-factor model. The correlation between an existing self-talk questionnaire (Brinthaupt's Self-Talk Scale) and the NIEQ inner speaking subscale provides one piece of concurrent validation.