The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Franz X. Vollenweider - One of the best experts on this subject based on the ideXlab platform.
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Dreamlike effects of LSD on waking imagery in humans depend on serotonin 2A receptor activation
Psychopharmacology, 2017Co-Authors: Rainer Kraehenmann, Dan Pokorny, Leonie Vollenweider, Katrin H. Preller, Thomas Pokorny, Erich Seifritz, Franz X. VollenweiderAbstract:Rationale Accumulating evidence indicates that the mixed serotonin and dopamine receptor agonist lysergic acid diethylamide (LSD) induces an altered State of Consciousness that resembles dreaming. Objectives This study aimed to test the hypotheses that LSD produces dreamlike waking imagery and that this imagery depends on 5-HT2A receptor activation and is related to subjective drug effects. Methods Twenty-five healthy subjects performed an audiorecorded guided mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). Cognitive bizarreness of guided mental imagery reports was quantified as a standardised formal measure of dream mentation. State of Consciousness was evaluated using the Altered State of Consciousness (5D-ASC) questionnaire. Results LSD, compared with placebo, significantly increased cognitive bizarreness ( p
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dreamlike effects of lsd on waking imagery in humans depend on serotonin 2a receptor activation
Psychopharmacology, 2017Co-Authors: Rainer Kraehenmann, Dan Pokorny, Leonie Vollenweider, Katrin H. Preller, Thomas Pokorny, Erich Seifritz, Franz X. VollenweiderAbstract:Accumulating evidence indicates that the mixed serotonin and dopamine receptor agonist lysergic acid diethylamide (LSD) induces an altered State of Consciousness that resembles dreaming. This study aimed to test the hypotheses that LSD produces dreamlike waking imagery and that this imagery depends on 5-HT2A receptor activation and is related to subjective drug effects. Twenty-five healthy subjects performed an audiorecorded guided mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). Cognitive bizarreness of guided mental imagery reports was quantified as a standardised formal measure of dream mentation. State of Consciousness was evaluated using the Altered State of Consciousness (5D-ASC) questionnaire. LSD, compared with placebo, significantly increased cognitive bizarreness (p < 0.001). The LSD-induced increase in cognitive bizarreness was positively correlated with the LSD-induced loss of self-boundaries and cognitive control (p < 0.05). Both LSD-induced increases in cognitive bizarreness and changes in State of Consciousness were fully blocked by ketanserin. LSD produced mental imagery similar to dreaming, primarily via activation of the 5-HT2A receptor and in relation to loss of self-boundaries and cognitive control. Future psychopharmacological studies should assess the differential contribution of the D2/D1 and 5-HT1A receptors to cognitive bizarreness.
Georg Northoff - One of the best experts on this subject based on the ideXlab platform.
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paradox of slow frequencies are slow frequencies in upper cortical layers a neural predisposition of the level State of Consciousness npc
Consciousness and Cognition, 2017Co-Authors: Georg NorthoffAbstract:Consciousness research has much focused on faster frequencies like alpha or gamma while neglecting the slower ones in the infraslow (0.001-0.1Hz) and slow (0.1-1Hz) frequency range. These slower frequency ranges have a "bad reputation" though; their increase in power can observed during the loss of Consciousness as in sleep, anesthesia, and vegetative State. However, at the same time, slower frequencies have been conceived instrumental for Consciousness. The present paper aims to resolve this paradox which I describe as "paradox of slow frequencies". I first show various data that suggest a central role of slower frequencies in integrating faster ones, i.e., "temporo-spatial integration and nestedness". Such "temporo-spatial integration and nestedness" is disrupted during the loss of Consciousness as in anesthesia and sleep leading to "temporo-spatial fragmentation and isolation" between slow and fast frequencies. Slow frequencies are supposedly mediated by neural activity in upper cortical layers in higher-order associative regions as distinguished from lower cortical layers that are related to faster frequencies. Taken together, slower and faster frequencies take on different roles for the level/State of Consciousness. Faster frequencies by themselves are sufficient and thus a neural correlate of Consciousness (NCC) while slower frequencies are a necessary non-sufficient condition of possible Consciousness, e.g., a neural predisposition of the level/State of Consciousness (NPC). This resolves the "paradox of slow frequencies" in that it assigns different roles to slower and faster frequencies in Consciousness, i.e., NCC and NPC. Taken as NCC and NPC, fast and slow frequencies including their relation as in "temporo-spatial integration and nestedness" can be considered a first "building bloc" of a future "temporo-spatial theory of Consciousness" (TTC) (Northoff, 2013; Northoff, 2014b; Northoff & Huang, 2017).
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"Paradox of slow frequencies" - Are slow frequencies in upper cortical layers a neural predisposition of the level/State of Consciousness (NPC)?
Consciousness and cognition, 2017Co-Authors: Georg NorthoffAbstract:Consciousness research has much focused on faster frequencies like alpha or gamma while neglecting the slower ones in the infraslow (0.001-0.1Hz) and slow (0.1-1Hz) frequency range. These slower frequency ranges have a "bad reputation" though; their increase in power can observed during the loss of Consciousness as in sleep, anesthesia, and vegetative State. However, at the same time, slower frequencies have been conceived instrumental for Consciousness. The present paper aims to resolve this paradox which I describe as "paradox of slow frequencies". I first show various data that suggest a central role of slower frequencies in integrating faster ones, i.e., "temporo-spatial integration and nestedness". Such "temporo-spatial integration and nestedness" is disrupted during the loss of Consciousness as in anesthesia and sleep leading to "temporo-spatial fragmentation and isolation" between slow and fast frequencies. Slow frequencies are supposedly mediated by neural activity in upper cortical layers in higher-order associative regions as distinguished from lower cortical layers that are related to faster frequencies. Taken together, slower and faster frequencies take on different roles for the level/State of Consciousness. Faster frequencies by themselves are sufficient and thus a neural correlate of Consciousness (NCC) while slower frequencies are a necessary non-sufficient condition of possible Consciousness, e.g., a neural predisposition of the level/State of Consciousness (NPC). This resolves the "paradox of slow frequencies" in that it assigns different roles to slower and faster frequencies in Consciousness, i.e., NCC and NPC. Taken as NCC and NPC, fast and slow frequencies including their relation as in "temporo-spatial integration and nestedness" can be considered a first "building bloc" of a future "temporo-spatial theory of Consciousness" (TTC) (Northoff, 2013; Northoff, 2014b; Northoff & Huang, 2017).
Rainer Kraehenmann - One of the best experts on this subject based on the ideXlab platform.
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Dreamlike effects of LSD on waking imagery in humans depend on serotonin 2A receptor activation
Psychopharmacology, 2017Co-Authors: Rainer Kraehenmann, Dan Pokorny, Leonie Vollenweider, Katrin H. Preller, Thomas Pokorny, Erich Seifritz, Franz X. VollenweiderAbstract:Rationale Accumulating evidence indicates that the mixed serotonin and dopamine receptor agonist lysergic acid diethylamide (LSD) induces an altered State of Consciousness that resembles dreaming. Objectives This study aimed to test the hypotheses that LSD produces dreamlike waking imagery and that this imagery depends on 5-HT2A receptor activation and is related to subjective drug effects. Methods Twenty-five healthy subjects performed an audiorecorded guided mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). Cognitive bizarreness of guided mental imagery reports was quantified as a standardised formal measure of dream mentation. State of Consciousness was evaluated using the Altered State of Consciousness (5D-ASC) questionnaire. Results LSD, compared with placebo, significantly increased cognitive bizarreness ( p
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dreamlike effects of lsd on waking imagery in humans depend on serotonin 2a receptor activation
Psychopharmacology, 2017Co-Authors: Rainer Kraehenmann, Dan Pokorny, Leonie Vollenweider, Katrin H. Preller, Thomas Pokorny, Erich Seifritz, Franz X. VollenweiderAbstract:Accumulating evidence indicates that the mixed serotonin and dopamine receptor agonist lysergic acid diethylamide (LSD) induces an altered State of Consciousness that resembles dreaming. This study aimed to test the hypotheses that LSD produces dreamlike waking imagery and that this imagery depends on 5-HT2A receptor activation and is related to subjective drug effects. Twenty-five healthy subjects performed an audiorecorded guided mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). Cognitive bizarreness of guided mental imagery reports was quantified as a standardised formal measure of dream mentation. State of Consciousness was evaluated using the Altered State of Consciousness (5D-ASC) questionnaire. LSD, compared with placebo, significantly increased cognitive bizarreness (p < 0.001). The LSD-induced increase in cognitive bizarreness was positively correlated with the LSD-induced loss of self-boundaries and cognitive control (p < 0.05). Both LSD-induced increases in cognitive bizarreness and changes in State of Consciousness were fully blocked by ketanserin. LSD produced mental imagery similar to dreaming, primarily via activation of the 5-HT2A receptor and in relation to loss of self-boundaries and cognitive control. Future psychopharmacological studies should assess the differential contribution of the D2/D1 and 5-HT1A receptors to cognitive bizarreness.
Ni Meng - One of the best experts on this subject based on the ideXlab platform.
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Altered State of Consciousness in mild traumatic brain injury in relation to utilization of services
Neurology, 2018Co-Authors: Meske Sam, Hazzard Joseph, Ni MengAbstract:Introduction Prevalence of traumatic brain injuries (TBI) in young adults on college campuses worldwide is extremely concerning, given that this age range is critical for cognitive and behavioral development. Impaired cognition can negatively affect academic performance and quality of life, while the prevalence of acute and/or chronic symptoms impact outcome measures of intellectual efficiency and mental health. It has been reported that a greater number of TBI symptoms and altered State of Consciousness are correlated with more academic challenges, chronic symptom prevalence, long-term deficits in executive, emotional, and behavioral functions, and lower employment outcome. Objective (1) Determine the relationship between altered or loss of Consciousness and utilization of services. (2) Compare gender differences in prevalence of altered State of Consciousness and service utilization from TBI. Methods A campus wide email was sent out, with a Qualtrics online survey asking questions that pertained to the participants9 TBI history, State of Consciousness immediately following the injury, symptom prevalence, and the campus services they utilized. Results of 194 respondents included in analysis, 36.6% indicated a loss of Consciousness and 35.6% altered Consciousness from TBI. At the same notion, only 9% of respondents indicated utilizing services. Interestingly, frequency of respondents9 who accessed services was lower for those who experienced only loss of Consciousness or both loss and altered Consciousness, and higher for those who experienced only altered Consciousness or neither (2.7%, 8.6%, 29.4%, 9.1%, respectively). No significant differences were observed between genders for altered State of Consciousness or services utilized. However, more men seemed to indicate that they experienced neither change in Consciousness (58.8% compared to 39.8% of females). Conclusions State of Consciousness may not be a good predictor of subsequent service utilization. Additionally, gender differences do not seem apparent when analyzing service utilization or level of Consciousness at time of injury.
Katrin H. Preller - One of the best experts on this subject based on the ideXlab platform.
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Dreamlike effects of LSD on waking imagery in humans depend on serotonin 2A receptor activation
Psychopharmacology, 2017Co-Authors: Rainer Kraehenmann, Dan Pokorny, Leonie Vollenweider, Katrin H. Preller, Thomas Pokorny, Erich Seifritz, Franz X. VollenweiderAbstract:Rationale Accumulating evidence indicates that the mixed serotonin and dopamine receptor agonist lysergic acid diethylamide (LSD) induces an altered State of Consciousness that resembles dreaming. Objectives This study aimed to test the hypotheses that LSD produces dreamlike waking imagery and that this imagery depends on 5-HT2A receptor activation and is related to subjective drug effects. Methods Twenty-five healthy subjects performed an audiorecorded guided mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). Cognitive bizarreness of guided mental imagery reports was quantified as a standardised formal measure of dream mentation. State of Consciousness was evaluated using the Altered State of Consciousness (5D-ASC) questionnaire. Results LSD, compared with placebo, significantly increased cognitive bizarreness ( p
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dreamlike effects of lsd on waking imagery in humans depend on serotonin 2a receptor activation
Psychopharmacology, 2017Co-Authors: Rainer Kraehenmann, Dan Pokorny, Leonie Vollenweider, Katrin H. Preller, Thomas Pokorny, Erich Seifritz, Franz X. VollenweiderAbstract:Accumulating evidence indicates that the mixed serotonin and dopamine receptor agonist lysergic acid diethylamide (LSD) induces an altered State of Consciousness that resembles dreaming. This study aimed to test the hypotheses that LSD produces dreamlike waking imagery and that this imagery depends on 5-HT2A receptor activation and is related to subjective drug effects. Twenty-five healthy subjects performed an audiorecorded guided mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). Cognitive bizarreness of guided mental imagery reports was quantified as a standardised formal measure of dream mentation. State of Consciousness was evaluated using the Altered State of Consciousness (5D-ASC) questionnaire. LSD, compared with placebo, significantly increased cognitive bizarreness (p < 0.001). The LSD-induced increase in cognitive bizarreness was positively correlated with the LSD-induced loss of self-boundaries and cognitive control (p < 0.05). Both LSD-induced increases in cognitive bizarreness and changes in State of Consciousness were fully blocked by ketanserin. LSD produced mental imagery similar to dreaming, primarily via activation of the 5-HT2A receptor and in relation to loss of self-boundaries and cognitive control. Future psychopharmacological studies should assess the differential contribution of the D2/D1 and 5-HT1A receptors to cognitive bizarreness.
