Consciousness and Cognition最新文献

Knowing when perceiving inner bodily signals better and when perceiving them worse is a health relevant but understudied dimension of interoception. Therefore, the present study assessed interoceptive metacognition (IMC) as the skill to adequately monitor interoceptive accuracy in the cardiac domain. We used the Graz Ambulatory Interoception task (GRAIT), which applied two intervals of the heartbeat tracking task 12 times a day for 3 days in total to n = 66 participants. We assessed IMC as the relative correspondence between interoceptive accuracy and the subjective confidence ratings. We found that 6 % of the total IMC variance was due to person, which was assessed reliable ($R_{\mathrm{KRn}}$=0.81). Furthermore, the between-person variation of IMC was negatively associated with the MAIA (especially attention regulation and self-regulation). People who believe that they are aware of their interoceptive experiences (MAIA) showed lower IMC. This study advocates the assessment of interoception in everyday life.

Predictive processing models are often ascribed a certain generality in conceptually unifying the relationships between perception, action, and cognition or the potential to posit a ‘grand unified theory’ of the mind. The limitations of this unification can be seen when these models are applied to specific cognitive phenomena or phenomenal consciousness. Our article discusses these shortcomings for predictive processing models of hallucinations by the example of the Charles-Bonnet-Syndrome. This case study shows that the current predictive processing account omits essential characteristics of stimulus-independent perception in general, which has critical phenomenological implications. We argue that the most popular predictive processing model of hallucinatory conditions – the strong prior hypothesis – fails to fully account for the characteristics of nonveridical perceptual experiences associated with Charles-Bonnet-Syndrome. To fill this explanatory gap, we propose that the strong prior hypothesis needs to include reality monitoring to apply to more than just veridical percepts.

Objectives

Pain causal attribution is the attribution of pain causes to self or others, which may depend on one's choice of actions. The study aimed to examine how the cognitive processes of pain causal attribution as one aspect of the sense of agency change in healthy individuals based on free or forced choice, using a temporal binding (TB) experimental task.

Methods

Participants pressed keys (action) in a combined TB task, with one key having a high probability of delivering pain (with tone). In fact, only the bias between the free-choice and the forced choice conditions was manipulated. Participants estimated the time between their action and tone, with shorter intervals indicating internal attribution.

Results

Interval estimation was significantly longer in the forced-choice condition than in the free-choice condition when a pain stimulus was delivered.

Conclusions

Explicit complaints of pain being caused by others may be represented in implicit cognitive processes.

Little is known about the perceptual characteristics of mental images nor how they vary across sensory modalities. We conducted an exhaustive survey into how mental images are experienced across modalities, mainly targeting visual and auditory imagery of a single stimulus, the letter “O”, to facilitate direct comparisons. We investigated temporal properties of mental images (e.g. onset latency, duration), spatial properties (e.g. apparent location), effort (e.g. ease, spontaneity, control), movement requirements (e.g. eye movements), real-imagined interactions (e.g. inner speech while reading), beliefs about imagery norms and terminologies, as well as respondent confidence. Participants also reported on the five traditional senses and their prominence during thinking, imagining, and dreaming. Overall, visual and auditory experiences dominated mental events, although auditory mental images were superior to visual mental images on almost every metric tested except regarding spatial properties. Our findings suggest that modality-specific differences in mental imagery may parallel those of other sensory neural processes.

Research has shown a prominent role for cortical hyperexcitability underlying aberrant perceptions, hallucinations, and distortions in human conscious experience – even in neurotypical groups. The rVLPFC has been identified as an important structure in mediating cognitive affective states / feeling conscious states. The current study examined the involvement of the rVLPFC in mediating cognitive affective states in those predisposed to aberrant experiences in the neurotypical population. Participants completed two trait-based measures: (i) the Cortical Hyperexcitability Index_II (CHi_II, a proxy measure of cortical hyperexcitability) and (ii) two factors from the Cambridge Depersonalisation Scale (CDS). An optimised 7-channel MtDCS montage for stimulation conditions (Anodal, Cathodal and Sham) was created targeting the rVLPFC in a single-blind study. At the end of each stimulation session, participants completed a body-threat task (BTAB) while skin conductance responses (SCRs) and psychological responses were recorded. Participants with signs of increasing cortical hyperexcitability showed significant suppression of SCRs in the Cathodal stimulation relative to the Anodal and sSham conditions. Those high on the trait-based measures of depersonalisation-like experiences failed to show reliable effects. Collectively, the findings suggest that baseline brain states can mediate the effects of neurostimulation which would be missed via sample level averaging and without appropriate measures for stratifying individual differences.

Acetylcholine is a neurotransmitter and neuromodulator involved in a variety of cognitive functions. Additionally, acetylcholine is involved in the regulation of REM sleep: cholinergic neurons in the brainstem and basal forebrain project to and innervate wide areas of the cerebral cortex, and reciprocally interact with other neuromodulatory systems, to produce the sleep-wake cycle and different sleep stages. Consciousness and cognition vary considerably across and within sleep stages, with metacognitive capacity being strikingly reduced even during aesthetically and emotionally rich dream experiences. A notable exception is the phenomenon of lucid dreaming—a rare state whereby waking levels of metacognitive awareness are restored during sleep—resulting in individuals becoming aware of the fact that they are dreaming. The role of neurotransmitters in these fluctuations of consciousness and cognition during sleep is still poorly understood. While recent studies using acetylcholinesterase inhibitors suggest a potential role of acetylcholine in the occurrence of lucid dreaming, the underlying mechanisms by which this effect is produced remains un-modelled and unknown; with the causal link between cholinergic mechanisms and upstream psychological states being complex and elusive. Several theories and approaches targeting the association between acetylcholine and metacognition during wakefulness and sleep are highlighted in this review, moving through microscopic, mesoscopic and macroscopic levels of analysis to detail this phenomenon at several organisational scales. Several exploratory hypotheses will be developed to guide future research towards fully articulating how metacognition is affected by activity at the acetylcholine receptor.

Potentially traumatic events elicit intrusive memories to which some individuals are more vulnerable than others. Lower abstract reasoning capacity has been related to more intrusive memories. A more perceptual processing style when encoding the event may mediate this link. Another potential mechanism is lower attentional control, resulting in greater attentional bias toward trauma-related content. We examined both of these possibilities using a trauma-analogue paradigm. One hundred and twenty participants completed abstract reasoning tasks. Then, 90 participants watched a negative video, and 30 participants watched a neutral video. The level of perceptual processing (P1) and attentional bias (RT) towards trauma-related stimuli were measured with a pictorial Stroop task while recording EEG. Intrusive memories were recorded for 5 days. Abstract reasoning was not associated with intrusive memories. However, lower abstract reasoning tended to be associated with more perceptual processing (greater P1 amplitude) following the negative video. More perceptual processing also tended to be related to more intrusive memories for younger participants. A more pronounced attentional bias was related to more intrusive memories, but only for women. Unexpectedly, also for women, better verbal reasoning was linked to a more pronounced attentional bias. Results are compared to existing studies and future implications are discussed.

Temporal binding refers to a subjective shortening of the interval between an action and its perceptual consequences. Temporal binding has often been used by researchers to indirectly measure participants’ sense of agency (SoA), or the subjective sense of causing something to happen. Other studies have proposed links between temporal binding and feelings of moral responsibility. The present study compared subjective interval estimates to feelings of responsibility in a between-subjects design (Exp 1) and a within-subjects design (Exp 2). Participants either estimated the interval between two events (two tones in the passive condition, or a keypress followed by a tone in active conditions) or rated their feeling of responsibility for the tone(s). Manipulations of participant involvement and choice impacted feelings of responsibility more than temporal estimates. Overall, the two dependent variables followed different patterns, suggesting subjective interval estimates may not be a reliable proxy for feelings of responsibility.

The self-prioritization effect (SPE) refers to the advantage in processing stimuli associated with oneself. Here, we addressed the SPE in an attentional blink (AB) task. In Experiment 1, shapes associated to you, friend, or stranger served as T1, and letter X as T2. The AB effect was larger for you than the other label conditions, and larger for friend condition than for stranger condition. We suggest that self-associated shape increased its perceptual salience, producing greater attentional capture. In Experiment 2 participants trained with a shape-label matching task to increase familiarity with the shape-label associations before performing the AB task. The difference between friend and stranger conditions disappeared, suggesting that the difference between the two conditions observed in Experiment 1 was mainly due to differences in familiarity or frequency of use. Importantly, the advantage of you over friend and stranger conditions remained, suggesting that the SPE is a genuine effect.

Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and mental health. The objective of this work is to study the information exchange between electrodes within and across the hemispheres during meditation using functional connectivity (FC) measures. We investigate the changes in the coherence between EEG electrode pairs during the meditation with open eyes practiced by long-term Brahmakumaris Rajyoga meditators and during listening to music by controls as the comparable task. FC derived from coherency, pairwise phase consistency (PPC) is used to study the changes in intra and interhemispheric coherence. Integrating connectivity (IC) derived from node degree strength has also been analyzed. Meditators show increased PPC in higher theta and alpha bands both within and across hemispheres. However, the control subjects with no knowledge of meditation show no change in theta band during the music session. Further, during baseline conditions, higher interhemispheric anterior to posterior IC is found in meditators in higher beta and slow gamma bands than controls. Distinct patterns of changes are observed with the PPC and IC measures in different frequency bands during meditation in the meditators and music-listening session in the control subjects indicating varied information processing between the right and left hemispheres. Increased IC is found between the frontal electrodes implying increased self-awareness in meditators. The PPC between the occipital electrodes in meditators is less than the controls in baseline condition indicating a possible modified visual information processing in Rajyoga meditators due to the long-term practice of meditation with open eyes. Overall, the changes in PPC and associated IC indicate increased functional integration during meditation supporting the hypothesis of communication through coherence and cortical integration theory during the non-ordinary state of consciousness induced by meditation.