Frontiers in Neurology
May 6, 2022
Hannah Ford, Clare L. Fraser, Emma J. Solly et al.
28 citations
Hallucinogen persisting perception disorder (HPPD) involves the return of perceptual symptoms after stopping hallucinogens. In a series of 13 patients and a review of 24 case reports, LSD, MDMA, and cannabinoids were commonly used, often together. The most frequent symptoms were visual snow, floaters, palinopsia, photophobia, and nyctalopia. Most ophthalmic and neurologic tests were normal. Two patients fully recovered, one with benzodiazepine treatment and one without; 25% of literature cases fully recovered. The symptoms overlap with Visual Snow Syndrome, suggesting that HPPD may be a secondary cause of VSS and that diagnostic criteria for HPPD should include visual snow, nyctalopia, photophobia, and floaters.
Frontiers in Neurology
January 1, 2020
Peter Fazekas, Georgina Nemeth
14 citations
Dreaming, mind-wandering, and hypnotic dreams may share underlying neural mechanisms, challenging earlier theories. Hobson's AIM theory mapped states of consciousness along dimensions of brain activity, input source, and neurochemical modulation, linking REM dreaming to other altered states like hypnosis. However, hypnosis is not a sleep-like state, and dreaming is not REM-centric. The neuro-cognitive theory places dreaming and mind-wandering on a continuum driven by default-mode network activity, questioning AIM theory. This paper argues that hypnotic dreams—experiences arising from explicit suggestions during hypnosis—can inform the neuro-cognitive theory, and comparing them with dreaming and mind-wandering may advance understanding of consciousness.
Frontiers in Neurology
January 1, 2020
Baland Jalal, Ludovico Moruzzi, Andrea Zangrandi et al.
13 citations
A small pilot study tested Meditation-Relaxation (MR) therapy for sleep paralysis (SP) in ten patients with narcolepsy. Over eight weeks, the six patients receiving MR therapy showed a 50% reduction in days with SP and a 54% reduction in total SP episodes in the last month, with large within-group effect sizes. The four patients in the control group (deep breathing) did not show similar improvement. These preliminary findings provide the first proof-of-concept evidence that MR therapy may reduce frequent SP, and the authors cautiously suggest the approach might generalize to people with isolated SP.
Frontiers in Neurology
January 1, 2019
Carla Thür, Marte Roel Lesur, Christopher J Bockisch et al.
12 citations
The sense of having a body depends on integrating multiple senses and prior beliefs, but the role of the vestibular system—which detects gravity—is not well understood. In an experiment, participants viewed a virtual body in front of them through a head-mounted display while receiving tactile stimulation on their back either synchronously or asynchronously. Tilting the virtual body created a conflict between visual and gravity-related cues about body orientation. Self-identification with the virtual body decreased when this visuo-graviceptive conflict was present.
Frontiers in Neurology
January 1, 2025
Martina Cacciatore, Francesca Giulia Magnani, Filippo Barbadoro et al.
11 citations
A systematic review of 167 articles over the past 20 years examined which thalamic nuclei are most involved in consciousness. Most evidence (284 out of 346 pieces) pointed to the intralaminar nuclear group, especially the centromedian-parafascicular complex (CM-Pf), as key for generating, modulating, and maintaining the level of consciousness. Although studies varied widely in methods (brain stimulation, anesthesia, brain damage) and populations (healthy and pathological humans, animals), the findings consistently support a central role for CM-Pf. These results reinforce the rationale for brain stimulation therapies targeting CM-Pf in disorders of consciousness and suggest other potential thalamic targets for intervention.
Frontiers in Neurology
June 29, 2023
Benjamin N. Blond, Emmanuelle A. D. Schindler
11 citations
A person with refractory right temporal lobe epilepsy who had an implanted responsive neurostimulation (RNS) system experienced a large increase in typical seizure frequency after ingesting a large dose of psychedelic mushrooms. This is the first reported case with electrographic confirmation of seizures linked to classic psychedelic drug use. The findings indicate that the risk of drug-induced seizures should be considered in the context of the re-emerging clinical use of classic psychedelics, particularly for individuals with a history of epilepsy and depending on drug doses and regimens.
Frontiers in Neurology
January 1, 2024
Wolfram Strupp
5 citations
Electromagnetic (EM) field theories of consciousness propose that an epineural EM field, through its physical binding properties, unifies disparate neuronal information differences from sensory and cognitive processes, enabling phenomenal consciousness. This article examines the physical properties of such a field, arguing that EM interaction provides both integration and necessary differentiating contrasts of information. It presents a new variant of EM field theory that addresses the problem of qualia in connection with emergentism. The author suggests that demonstrating the epineural EM field's decisive role in consciousness would reduce the need for metaphysical assumptions about the binding problem. An experimental method using shielding of EM fields, rather than external stimuli, is proposed to test the theory without affecting wired neuronal processing.
Frontiers in Neurology
January 1, 2023
Melisa A Gantt
5 citations
Binaural beats can enhance sleep quality by manipulating brainwaves. In a study involving 168 participants, those using theta/delta binaural beat frequencies (BBFs) showed significant improvements in sleep efficiency compared to music alone. Cohort 1 included 106 participants with poor sleep quality, while Cohort 2 had 62 blinded participants. By systematically sequencing various BBFs, the aim is to sustain sleep and improve overall efficiency. Successful implementation could offer new solutions for those struggling with sleep disorders, potentially benefiting millions.
Frontiers in Neurology
June 25, 2025
Rania Abutarboush, Usmah Kawoos, Rita de Gasperi et al.
3 citations
Repetitive low-level blast exposure in male rats chronically reduces serotonin 2A receptor (5-HT2AR) levels in the anterior cerebral cortex, a change detectable from 1 month to at least 12 months after exposure but not at 2 weeks. The hippocampus and amygdala showed variable receptor changes. 5-HT2AR expression correlated differently with certain behavioral measures in blast-exposed versus control rats. These findings suggest a neurochemical basis for blast-induced cognitive and PTSD-related behavioral changes and identify 5-HT2AR as a potential therapeutic target for treating such symptoms in Veterans.
Frontiers in Neurology
January 1, 2025
Tan Zhang, Nan Wang, Xiaoke Chai et al.
2 citations
In patients with disorders of consciousness, acute pressure pain stimulation did not produce significant changes in oxygenated or deoxygenated hemoglobin concentrations across multiple brain regions, indicating minimal activation of pain-related areas. However, functional connectivity between the primary somatosensory cortex, primary motor cortex, and dorsolateral prefrontal cortex significantly increased during stimulation, with correlation coefficients exceeding 0.9. This enhanced coordination among sensory, motor, and cognitive regions suggests that the brain continues to process pain information through altered network connectivity even when regional activation is absent. The findings underscore the potential of functional connectivity measures for evaluating pain processing in patients with disorders of consciousness.
Frontiers in Neurology
January 1, 2025
Chunyan Zhao, Meijiao Zhang, Qingping Zhang et al.
2 citations
Among 20 patients with the claustrum sign on brain MRI, febrile infection-related epilepsy syndrome (FIRES) was the most common diagnosis (60%), followed by antibody-negative autoimmune encephalitis (20%), myelin oligodendrocyte glycoprotein antibody-associated disease (15%), and Wilson's disease (5%). Seizures occurred in 85% and impaired consciousness in 70%. The claustrum sign appeared a median of 11.5 days after symptom onset, was transient in most cases, and resolved by a median of 53 days. Patients with FIRES had the worst outcomes—all developed chronic epilepsy, 75% had poor memory and calculation—while those with autoimmune encephalitis or MOGAD had favorable outcomes. The claustrum sign likely represents a transient neuroinflammatory lesion and may be an imaging marker of neuroinflammation, with lesions potentially contributing to seizures and impaired consciousness through disrupted connectivity.
Frontiers in Neurology
January 1, 2025
Sui H Wong, Janet Wingrove
1 citation
Visual snow syndrome involves intrusive visual symptoms linked to dysregulation in brain networks such as the Salience Network, Default Mode Network, and thalamocortical circuits. This perspective paper proposes that mindfulness-based cognitive therapy modified for visual symptoms (MBCT-vision) may help by addressing attentional mechanisms like heightened vigilance and threat attribution. The intervention enhances attentional flexibility, metacognitive awareness, and a non-reactive stance toward symptoms, with group format offering additional validation. Potential neuroplastic changes in the Default Mode Network are discussed as underlying improvements.
Frontiers in Neurology
January 1, 2025
Wenjia He, Xinyu Lyu, Hui Zhang et al.
In people with benign paroxysmal positional vertigo (BPPV), resting-state functional connectivity (FC) between brain regions involved in vestibular, motor, and sensory processing is abnormally elevated compared to healthy controls. After a canalith repositioning maneuver, whole-brain average FC strength decreased significantly, and connectivity between specific region pairs—including prefrontal cortex, occipital cortex, middle temporal gyrus, motor cortex, and somatosensory cortex—returned to normal levels. Clinical symptoms also improved: the Dizziness Handicap Inventory score dropped by 23.4% and the Visual Analogue Scale score showed a significant reduction. The findings suggest BPPV involves compensatory enhancement of the vestibulo-sensorimotor network, and that repositioning therapy restores pathologically enhanced FC to normal, supporting functional near-infrared spectroscopy as a potential objective biomarker for evaluating BPPV neural mechanisms and treatment efficacy.
Frontiers in Neurology
January 1, 2025
Xiaofei Pang, Dong Qiu, Xiaowen He et al.
In patients with post-stroke mild depression, adding mindfulness-based stress reduction to conventional intervention therapy improved depression and cognitive outcomes more than conventional therapy alone. Eighty patients were randomly assigned to either conventional therapy alone or conventional therapy plus an 8-week mindfulness-based stress reduction plan. Both groups showed reduced depression scores (HAMD-17, SDS) and inflammatory markers (TNF-α, hs-CRP, IL-6) and improved cognitive scores (MMSE, MoCA) after treatment. The combination group had significantly lower depression scores and inflammatory factor levels and significantly higher cognitive scores than the control group. The authors conclude that the combined approach improves overall response rate and has a significant advantage in reducing depression.
Frontiers in Neurology
January 1, 2020
Alain Nicolas, Perrine Ruby
A review of experimental results from the past 60 years finds that most antidepressant drugs reduce dream recall frequency, and improvement in depressive symptoms is linked to more positive emotions in dream content. Sedative psychotropic drugs also reduce dream recall frequency by improving sleep quality, but their effect on dream content is unclear. Nightmare frequency can increase with sleep-disrupting molecules or withdrawal of some psychotropic drugs. The impact of these drugs on REM sleep does not explain changes in dream recall frequency; instead, reducing intra-sleep awakenings best accounts for the reduction in dream recall, consistent with the arousal-retrieval model. Other factors like interest in dreams, awakening method, and personality traits also influence variability in results.
Frontiers in Neurology
January 1, 2020
Benjamin Putois, Wendy Leslie, Claire Asfeld et al.
To ensure valid results in clinical studies of dreams and nightmares, researchers must control factors that influence how often people report dreams. This article presents methodological recommendations for group-matching designs and for clinicians monitoring nightmare frequency during interventions. The main factors affecting dream recall include demographic variables, psychological characteristics, pathological dimensions, and substance use. A set of questionnaires is proposed to easily measure these control variables, helping to distinguish genuine treatment effects from confounding influences.
Frontiers in Neurology
September 18, 2019
Yang Wang, Yun Qin, Hui Li et al.
Internet addiction is linked to altered communication patterns across the whole brain. Individuals with internet addiction showed increased functional connectivity density in regions involved in cognitive control and the default mode network, including the right dorsolateral prefrontal cortex, left parahippocampal gyrus, cerebellum, bilateral middle cingulate cortex, and superior temporal pole. Decreased connectivity density appeared in the right inferior parietal lobe and bilateral calcarine and lingual gyrus, areas tied to visual attention. Scores on the Internet Addiction Test correlated with connectivity changes in the left parahippocampal gyrus and bilateral superior temporal pole. These patterns resemble those seen in substance addiction and share neurobiological features with attention deficit/hyperactivity disorder.
Frontiers in Neurology
January 1, 2019
Maaike M Rademaker, Inge Stegeman, Krysten E Ho-Kang-You et al.
A systematic review of seven studies (425 patients) examined whether mindfulness-based interventions (MBIs) such as MBCT and MBSR reduce tinnitus distress and improve anxiety or depression in adults with tinnitus. Two of three randomized controlled trials found a statistically significant decrease in tinnitus distress scores immediately after treatment in the mindfulness group compared to controls. Six of seven studies showed a significant decrease in tinnitus distress scores directly after therapy. However, only one of three RCTs found a significant improvement in depression scores, and no effect on anxiety was observed. Long-term effects remain uncertain.
Frontiers in Neurology
January 1, 2019
Serena Scarpelli, Aurora D'Atri, Chiara Bartolacci et al.
Frontal theta oscillations during the last five minutes of REM sleep predict whether older adults will recall a dream upon waking, replicating a pattern previously established in young adults. In a study of 21 healthy older volunteers (mean age 69.2) and 20 young adults (mean age 23.4), dream recall occurred when REM sleep showed rhythmic frontal theta activity. No interaction between age and recall status was found, indicating the same brain activity supports dream recall in both age groups. Theta oscillations were more abundant in young participants, and the authors distinguish this rhythmic theta from non-rhythmic theta linked to sleepiness or clinical cortical slowing.
Frontiers in Neurology
January 1, 2019
Ahmed S BaHammam, Aljohara S Almeneessier
Obstructive sleep apnea (OSA) disrupts sleep and oxygen levels, which may affect dreaming. Some studies report that people with OSA have fewer dreams, while others find they have more emotionally intense dreams, often with violent or hostile themes. Respiratory-related dream content is rare. A clear link exists between post-traumatic stress disorder, co-occurring OSA, and nightmares. Continuous positive airway pressure (CPAP) treatment reduces nightmare frequency. Several studies show that more severe OSA, measured by the apnea-hypopnea index, is associated with lower dream recall. Future research should distinguish between patients with general OSA and those with rapid eye movement (REM)-predominant OSA.
Frontiers in Neurology
August 28, 2018
Audrey Vanhaudenhuyse, Vanessa Charland-Verville, Aurore Thibaut et al.
A patient diagnosed with unresponsive wakefulness syndrome/vegetative state for 20 years was found to be fully conscious and able to communicate functionally after repeated standardized behavioral exams and neuroimaging (MRI and PET). The diagnosis was revised to incomplete locked-in syndrome, with the main lesion in the brainstem. The authors propose that clinical evaluations of severely brain-damaged patients with motor impairment should routinely include repeated behavioral assessments and neuroimaging.
Frontiers in Neurology
January 1, 2012
Tore Nielsen
Dream recall frequency peaks in early adulthood (ages 20-29) and then declines over the next 20 years, with different patterns for males and females. Males show a gradual decline starting in their 30s, reaching a low point in their 40s, while females experience a later, more abrupt decline starting in their 40s and reaching a low in their 50s. Sex differences in recall are most pronounced between ages 14 and 44. Dream theme diversity decreases linearly with age for both sexes up to ages 50-59, then drops more sharply for those aged 60-79, with a sex difference favoring males only during adolescence (ages 10-19). These patterns parallel age-related changes in sleep structure, particularly decreasing REM sleep, as well as declines in episodic and autobiographical memory.