Reporting dream experience : why (not) to be skeptical about dream reports

Are dreams subjective experiences during sleep? Is it like something to dream, or is it only like something to remember dreams after awakening? Specifically, can dream reports be trusted to reveal what it is like to dream, and should they count as evidence for saying that dreams are conscious experiences at all? The goal of this article is to investigate the relationship between dreaming, dream reporting and subjective experience during sleep. I discuss different variants of philosophical skepticism about dream reporting and argue that they all fail. Consequently, skeptical doubts about the trustworthiness of dream reports are misguided, and for systematic reasons. I suggest an alternative, anti-skeptical account of the trustworthiness of dream reports. On this view, dream reports, when gathered under ideal reporting conditions and according to the principle of temporal proximity, are trustworthy (or transparent) with respect to conscious experience during sleep. The transparency assumption has the status of a methodologically necessary default assumption and is theoretically justified because it provides the best explanation of dream reporting. At the same time, it inherits important insights from the discussed variants of skepticism about dream reporting, suggesting that the careful consideration of these skeptical arguments ultimately leads to a positive account of why and under which conditions dream reports can and should be trusted. In this way, moderate distrust can be fruitfully combined with anti-skepticism about dream reporting. Several perspectives for future dream research and for the comparative study of dreaming and waking experience are suggested

Extending the Explanandum: A Commentary on Andy Clark

In this commentary, I suggest that the predictive processing framework (PP) might be applicable to areas beyond those identified by Clark. In particular, PP may be relevant for our understanding of perceptual content, consciousness, and for applied cognitive neuroscience. My main claim for each area is as follows:PP urges an organism-relative conception of perceptual content.Historical a priori accounts of the structure of perceptual experience converge with results from PP. There are a number of areas in which PP can find important practical applications, including education, public policy, and social interaction

Mental states as emergent properties. From walking to consciousness

Cruse H, Schilling M. Mental states as emergent properties. From walking to consciousness. In: Metzinger T, Windt J, eds. Open Mind. Frankfurt/M.: MIND Group Frankfurt/M.; 2015.In this article we propose a bottom-up approach to higher-level mental states, such as emotions, attention, intention, volition, or consciousness. The idea behind this bottom-up approach is that higher-level properties may arise as emergent properties, i.e., occur without requiring explicit implementation of the phenomenon under examination. Using a neural architecture that shows the abilities of autonomous agents, we want to come up with quantitative hypotheses concerning cognitive mechanisms, i.e., to come up with testable predictions concerning the underlying structure and functioning of an autonomous system that can be tested in a robot-control system. We do not want to build an artificial system that is, for example, conscious in the first place. On the contrary, we want to construct a system able to control behavior. Only then will this system be used as a tool to test to what extent descriptions of mental phenomena used in psychology or philosophy of mind may be applied to such an artificial system. Originally these phenomena are necessarily defined using verbal formulations that allow for interpreting them differently. A functional definition, in contrast, does not suffer from being ambiguous, because it can be expressed explicitly using mathematical formulations that can be tested, for example, in a quantitative simulation. It is important to note that we are not concerned with the “hard” problem of consciousness, i.e., the subjective aspect of mental phenomena. This approach is possible because, adopting a monist view, we assume that we can circumvent the “hard” problem without losing information concerning the possible function of these phenomena. In other words, we assume that phenomenality is an inherent property of both access consciousness and metacognition (or reflexive consciousness). Following these arguments, we claim that our network does not only show emergent properties on the reactive level; it also shows that mental states, such as emotions, attention, intention, volition, or consciousness can be observed, too. Concerning consciousness, we argue that properties assumed to partially constitute access consciousness are present in our network, including the property of global availability, which means that elements of the procedural memory can be addressed even if they do not belong to the current context. Further expansions are discussed that may allow for the recognition of properties attributed to metacognition or reflexive consciousness

The Dream Catcher experiment: blinded analyses failed to detect markers of dreaming consciousness in EEG spectral power

The Dream Catcher test defines the criteria for a genuine discovery of the neural constituents of phenomenal consciousness. Passing the test implies that some patterns of purely brain-based data directly correspond to the subjective features of phenomenal experience, which would help to bridge the explanatory gap between consciousness and brain. Here, we conducted the Dream Catcher test for the first time in a step-wise and simplified form, capturing its core idea. The Dream Catcher experiment involved a Data Team, which measured participants' brain activity during sleep and collected dream reports, and a blinded Analysis Team, which was challenged to predict, based solely on brain measurements, whether or not a participant had a dream experience. Using a serial-awakening paradigm, the Data Team prepared 54 1-min polysomnograms of non-rapid eye movement sleep-27 of dreamful sleep and 27 of dreamless sleep (three of each condition from each of the nine participants)-redacting from them all associated participant and dream information. The Analysis Team attempted to classify each recording as either dreamless or dreamful using an unsupervised machine learning classifier, based on hypothesis-driven, extracted features of electroencephalography (EEG) spectral power and electrode location. The procedure was repeated over five iterations with a gradual removal of blindness. At no level of blindness did the Analysis Team perform significantly better than chance, suggesting that EEG spectral power could not be utilized to detect signatures specific to phenomenal consciousness in these data. This study marks the first step towards realizing the Dream Catcher test in practice

Modulating dream experience: Noninvasive brain stimulation over the sensorimotor cortex reduces dream movement

Funder: Signe ja Ane Gyllenbergin Säätiö (Signe and Ane Gyllenberg Foundation); doi: https://doi.org/10.13039/501100004325Abstract: Recently, cortical correlates of specific dream contents have been reported, such as the activation of the sensorimotor cortex during dreamed hand clenching. Yet, despite a close resemblance of such activation patterns to those seen during the corresponding wakeful behaviour, the causal mechanisms underlying specific dream contents remain largely elusive. Here, we aimed to investigate the causal role of the sensorimotor cortex in generating movement and bodily sensations during REM sleep dreaming. Following bihemispheric transcranial direct current stimulation (tDCS) or sham stimulation, guided by functional mapping of the primary motor cortex, naive participants were awakened from REM sleep and responded to a questionnaire on bodily sensations in dreams. Electromyographic (EMG) and electroencephalographic (EEG) recordings were used to quantify physiological changes during the preceding REM period. We found that tDCS, compared to sham stimulation, significantly decreased reports of dream movement, especially of repetitive actions. Other types of bodily experiences, such as tactile or vestibular sensations, were not affected by tDCS, confirming the specificity of stimulation effects to movement sensations. In addition, tDCS reduced EEG interhemispheric coherence in parietal areas and affected the phasic EMG correlation between both arms. These findings show that a complex temporal reorganization of the motor network co-occurred with the reduction of dream movement, revealing a link between central and peripheral motor processes and movement sensations of the dream self. tDCS over the sensorimotor cortex interferes with dream movement during REM sleep, which is consistent with a causal contribution to dream experience and has broader implications for understanding the neural basis of self-experience in dreams

Clinical and radiological outcome of conservative vs. surgical treatment of atraumatic degenerative rotator cuff rupture: design of a randomized controlled trial

Background: Subacromial impingement syndrome is a frequently observed disorder in orthopedic practice. Lasting symptoms and impairment may occur when a subsequent atraumatic rotator cuff rupture is also present. However, degenerative ruptures of the rotator cuff can also be observed in asymptomatic elderly individuals. Treatment of these symptomatic degenerative ruptures may be conservative or surgical. Acceptable results are reported for both treatment modalities. No evidence-based level-1 studies have been conducted so far to compare these treatment modalities. The objective of this study is to determine whether there is a difference in outcome between surgical reconstruction and conservative treatment of a degenerative atraumatic rotator cuff tendon rupture. Methods/Design: A randomized controlled trial will be conducted. Patients aged between 45 and 75 with a symptomatic atraumatic rotator cuff rupture as diagnosed by MRI will be included. Exclusion criteria are traumatic rotator cuff rupture, frozen shoulder and diabetes mellitus. Patients will be randomized into two groups. Conservative treatment includes physical therapy according to a standardized protocol, NSAIDs and, if indicated, subacromial infiltration with a local anesthetic and corticosteroids. Surgical reconstruction is performed under general anesthesia in combination with an interscalenus plexus block. An acromioplasty with reconstruction of the rotator cuff tendon is performed, as described by Rockwood et al. Measurements take place preoperatively and 6 weeks, 3 months, 6 months and 1 year postoperatively. The primary outcome measure is the Constant score. Secondary measures include both disease-specific and generic outcome measures, and an economic evaluation. Additionally, one year after inclusion a second MRI will be taken of all patients in order to determine whether extent and localization of the rupture as well as the amount of fatty degeneration are prognostic factors. Discussion: Both surgical as conservative treatment of a symptomatic atraumatic rotator cuff tendon rupture is used in current practice. There is a lack of level-1 studies comparing surgical vs. conservative treatment. This randomized controlled trial has been designed to determine whether the surgical treatment of a degenerative atraumatic rotator cuff tendon rupture may lead to a better functional and radiological outcome than conservative treatment after one year of follow-up

Focused wave interactions with floating structures: A blind comparative study

The paper presents results from the Collaborative Computational Project in Wave Structure Interaction (CCP-WSI) Blind Test Series 2. Without prior access to the physical data, participants, with numerical methods ranging from low-fidelity linear models to fully non-linear Navier−Stokes (NS) solvers, simulate the interaction between focused wave events and two separate, taut-moored, floating structures: a hemispherical-bottomed cylinder and a cylinder with a moonpool. The ‘blind’ numerical predictions for heave, surge, pitch and mooring load, are compared against physical measurements. Dynamic time warping is used to quantify the predictive capability of participating methods. In general, NS solvers and hybrid methods give more accurate predictions; however, heave amplitude is predicted reasonably well by all methods; and a WEC-Sim implementation, with CFD-informed viscous terms, demonstrates comparable predictive capability to even the stronger NS solvers. Large variations in the solutions are observed (even among similar methods), highlighting a need for standardisation in the numerical modelling of WSI problems

Dreams and Dreaming

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