Conference Presentations
Yanakieva, S., Luke, D. P., Jansari, A., & Terhune, D. B. (2018, October). Acquired synaesthesia ... more Yanakieva, S., Luke, D. P., Jansari, A., & Terhune, D. B. (2018, October). Acquired synaesthesia following 2C-B drug use. Poster presented at Bridging Senses: New Developments in Synaesthesia conference, The Royal Society, 22nd -23rd October.
Multiple psychedelic drugs, particularly those targeting the serotonin system can elicit experiences, resembling those of developmental synesthesia. Although controversial, drug induced synesthesia can consequentially counter some of the existing theories of synesthesia. The study presents the case of LW who is a 29-year-old-man, experiencing multiple forms of synesthesia including day-color, sound-color, emotion-color, smell-color, and face-color synesthesia, following the ingestion of 70-80mg of 2C-B at the age of 22. LW’s face-color synesthesia is the strongest, particularly when faces convey particular emotional expressions. He perceives color as visuospatial co-localized with inducing faces (projector synesthesia). The study aim was to examine whether LW’s face-color synesthesia met the criteria for automaticity and consistency, which are the main markers of developmental synesthesia. LW and ten non-synesthees completed synesthetic consistency and face-color priming tasks. LW’s face-color synesthesia met the criteria for consistency and he also displayed a larger congruency effect (incongruent – congruent) than controls, thereby reflecting that LW’s face-synesthesia also exhibits automaticity. 2C-B appears to function as a partial serotonin agonist, and the overdose may have triggered hyper excitability in LW’s visual cortex resulting in sustained color experiences that were eventually producing consistent and automatic associations with emotional faces, through consolidation over time.
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Luke, D., & Yanakieva, S. (2016, June). The transpersonal psychedelic experience and change in ec... more Luke, D., & Yanakieva, S. (2016, June). The transpersonal psychedelic experience and change in ecological attitude and behaviour. Paper presented at the International Conference on Psychedelics Research, Stichting Open, Amsterdam, 3rd-5th June.
Mapping the empirical territory between the growing research fields of ecopsychology and psychedelic therapy there is virtually no data on the relationship between the psychedelic experience and the apparent concomitant development of increased eco-consciousness, despite numerous anecdotal reports. In an anonymous online survey 150 psychedelic users reported on their use of psychedelics, their experiences in relation to Nature, and how their experience had changed their attitudes towards ecological issues. It was hypothesised that the majority of psychedelic substance users would report an increased connection with Nature and expanded eco-consciousness as a result of their experience, and that the use of psychedelics would generally increase rather than decrease eco-consciousness. It was also expected that specific types of substances would lead to specific types of transpersonal-type encounter experiences. The results were consistent with the hypotheses and are discussed in detail.
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Peer-review Journal Articles
Retrosplenial cortex contains two principal subdivisions, area 29 (granular) and area 30 (dysgran... more Retrosplenial cortex contains two principal subdivisions, area 29 (granular) and area 30 (dysgranular). Their respective anatomical connections in the rat brain indicate that area 29 is the primary recipient of hippocampal and parahippocampal spatial and contextual information while area 30 is the primary interactor with current visual information. Lesion studies and measures of neuronal activity in rodents indicate that retrosplenial cortex helps to integrate space from different perspectives, e.g., egocentric and allocentric, providing landmark and heading cues for navigation and spatial learning. It provides a repository of scene information that, over time, becomes increasingly independent of the hippocampus. These processes, reflect the interactive actions between areas 29 and 30, along with their convergent influences on cortical and thalamic targets. Consequently, despite their differences, both areas 29 and 30 are necessary for an array of spatial and learning problems.
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Yanakieva, S., Luke, D.P., Jansari, A., & Terhune, D. B. (2019). Acquired synaesthesia following ... more Yanakieva, S., Luke, D.P., Jansari, A., & Terhune, D. B. (2019). Acquired synaesthesia following 2C-B use. Psychopharmacology, 236, 2287–2289. https://doi.org/10.1007/s00213-019-05242-y
Psychedelic drugs reliably trigger experiences that closely resemble synaesthesia (Luke and Terhune 2013), a condition in which inducer stimuli will reliably and automatically elicit atypical concurrent experiences (Ward 2013). These transient episodes are considered controversial because they do not meet behavioural diagnostic criteria for developmental synaesthesia (Terhune et al. 2016). However, if these behavioural markers are attributable to the consolidation of synaesthetic associations over time (Terhune et al. 2016), they should be observed in cases of acquired synaesthesia. Here we report a case of drug-induced acquired synaesthesia (LW) that meets standard diagnostic criteria for developmental synaesthesia.
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Yanakieva, S., Polychroni, N., Family, N., Williams, L. T. J., Luke, D. P., Terhune, D. B. (2018)... more Yanakieva, S., Polychroni, N., Family, N., Williams, L. T. J., Luke, D. P., Terhune, D. B. (2018). The effects of microdose LSD on time perception: a randomised, double-blind, placebo-controlled trial. Psychopharmacology, 236, 1159–1170. doi: 10.1007/s00213-018-5119-x
Rationale: Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterations in time perception has implications for its impact on conscious states and a range of psychological functions that necessitate precise interval timing. However, interpretation of this research is hindered by methodological limitations and an inability to dissociate direct neurochemical effects on interval timing from indirect effects attributable to altered states of consciousness.
Methods: We conducted a randomised, double-blind, placebo-controlled study contrasting oral administration of placebo with three microdoses of LSD (5, 10, and 20 μg) in older adults. Subjective drug effects were regularly recorded and interval timing was assessed using a temporal reproduction task spanning subsecond and suprasecond intervals.
Results: LSD conditions were not associated with any robust changes in self-report indices of perception, mentation, or concentration. LSD reliably produced over-reproduction of temporal intervals of 2000 ms and longer with these effects most pronounced in the 10 μg dose condition. Hierarchical regression analyses indicated that LSD-mediated over-reproduction was independent of marginal differences in self-reported drug effects across conditions.
Conclusions: These results suggest that microdose LSD produces temporal dilation of suprasecond intervals in the absence of subjective alterations of consciousness.
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Papers
The connectivity and interplay between the prefrontal cortex and hippocampus underpin a number of... more The connectivity and interplay between the prefrontal cortex and hippocampus underpin a number of key cognitive processes, with changes in these interactions being implicated in both neurodevelopmental as well as neurodegenerative conditions. Understanding the precise cellular connections through which this circuit is organised is, therefore, vital for understanding these same processes. Overturning earlier findings, a recent study described a novel excitatory projection from anterior cingulate cortex to hippocampus. We sought to validate this unexpected finding using multiple, complementary methods: anterograde and retrograde anatomical tracing, using both anterograde and retrograde AAVs and monosynaptic rabies tracing. Additionally, an extensive data search of the Allen Projection Brain Atlas database was conducted to find the stated projection within any of the deposited anatomical studies, as an independent verification of our own results. However, we failed to find any evidence...
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Multiple psychedelic drugs, particularly those targeting the serotonin system can elicit experien... more Multiple psychedelic drugs, particularly those targeting the serotonin system can elicit experiences, resembling those of developmental synesthesia. Although controversial, drug induced synesthesia can consequentially counter some of the existing theories of synesthesia. The study presents the case of LW who is a 29-year-old-man, experiencing multiple forms of synesthesia including day-color, sound-color, emotion-color, smell-color, and face-color synesthesia, following the ingestion of 70-80mg of 2C-B at the age of 22. LW’s face-color synesthesia is the strongest, particularly when faces convey particular emotional expressions. He perceives color as visuospatial co-localized with inducing faces (projector synesthesia). The study aim was to examine whether LW’s face-color synesthesia met the criteria for automaticity and consistency, which are the main markers of developmental synesthesia. LW and ten non-synesthees completed synesthetic consistency and face-color priming tasks. LW’s...
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Psychopharmacology, 2020
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Neurobiology of Learning and Memory, 2021
Retrosplenial cortex contains two principal subdivisions, area 29 (granular) and area 30 (dysgran... more Retrosplenial cortex contains two principal subdivisions, area 29 (granular) and area 30 (dysgranular). Their respective anatomical connections in the rat brain indicate that area 29 is the primary recipient of hippocampal and parahippocampal spatial and contextual information while area 30 is the primary interactor with current visual information. Lesion studies and measures of neuronal activity in rodents indicate that retrosplenial cortex helps to integrate space from different perspectives, e.g., egocentric and allocentric, providing landmark and heading cues for navigation and spatial learning. It provides a repository of scene information that, over time, becomes increasingly independent of the hippocampus. These processes, reflect the interactive actions between areas 29 and 30, along with their convergent influences on cortical and thalamic targets. Consequently, despite their differences, both areas 29 and 30 are necessary for an array of spatial and learning problems.
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European Journal of Neuroscience
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Psychopharmacology
Yanakieva, S., Luke, D.P., Jansari, A., & Terhune, D. B. (2019). Acquired synaesthesia fo... more Yanakieva, S., Luke, D.P., Jansari, A., & Terhune, D. B. (2019). Acquired synaesthesia following 2C-B use. Psychopharmacology, 236, 2287–2289. https://doi.org/10.1007/s00213-019-05242-y Psychedelic drugs reliably trigger experiences that closely resemble synaesthesia (Luke and Terhune 2013), a condition in which inducer stimuli will reliably and automatically elicit atypical concurrent experiences (Ward 2013). These transient episodes are considered controversial because they do not meet behavioural diagnostic criteria for developmental synaesthesia (Terhune et al. 2016). However, if these behavioural markers are attributable to the consolidation of synaesthetic associations over time (Terhune et al. 2016), they should be observed in cases of acquired synaesthesia. Here we report a case of drug-induced acquired synaesthesia (LW) that meets standard diagnostic criteria for developmental synaesthesia.
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Psychopharmacology
Rationale Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterati... more Rationale Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterations in time perception has implications for its impact on conscious states and a range of psychological functions that necessitate precise interval timing. However, interpretation of this research is hindered by methodological limitations and an inability to dissociate direct neurochemical effects on interval timing from indirect effects attributable to altered states of consciousness. Methods We conducted a randomised, double-blind, placebo-controlled study contrasting oral administration of placebo with three microdoses of LSD (5, 10, and 20 μg) in older adults. Subjective drug effects were regularly recorded and interval timing was assessed using a temporal reproduction task spanning subsecond and suprasecond intervals. Results LSD conditions were not associated with any robust changes in self-report indices of perception, mentation, or concentration. LSD reliably produced over-reprod...
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Oxford Scholarship Online
I am 22 years old and have just completed my first degree at a UK university. Originally from Bul... more I am 22 years old and have just completed my first degree at a UK university. Originally from Bulgaria, I found myself on a plane to the UK at the age of 19. Although I am proud of my country’s rich history, in the 21st century, Bulgaria does not have enough to satisfy my ambitions. Being financially independent from my parents, pursuing a research career, belonging to a scientific community, and feeling safe and encouraged to speak my mind—these were things I felt nearly impossible to achieve in my fatherland, and they reinforced my feelings of not belonging....
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Psychopharmacology
Rationale Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterati... more Rationale Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterations in time perception has implications for its impact on conscious states and a range of psychological functions that necessitate precise interval timing. However, interpretation of this research is hindered by methodological limitations and an inability to dissociate direct neurochemical effects on interval timing from indirect effects attributable to altered states of consciousness. Methods We conducted a randomised, double-blind, placebo-controlled study contrasting oral administration of placebo with three microdoses of LSD (5, 10, and 20 μg) in older adults. Subjective drug effects were regularly recorded and interval timing was assessed using a temporal reproduction task spanning subsecond and suprasecond intervals. Results LSD conditions were not associated with any robust changes in self-report indices of perception, mentation, or concentration. LSD reliably produced over-reprod...
Bookmarks Related papers MentionsView impact
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Conference Presentations
Multiple psychedelic drugs, particularly those targeting the serotonin system can elicit experiences, resembling those of developmental synesthesia. Although controversial, drug induced synesthesia can consequentially counter some of the existing theories of synesthesia. The study presents the case of LW who is a 29-year-old-man, experiencing multiple forms of synesthesia including day-color, sound-color, emotion-color, smell-color, and face-color synesthesia, following the ingestion of 70-80mg of 2C-B at the age of 22. LW’s face-color synesthesia is the strongest, particularly when faces convey particular emotional expressions. He perceives color as visuospatial co-localized with inducing faces (projector synesthesia). The study aim was to examine whether LW’s face-color synesthesia met the criteria for automaticity and consistency, which are the main markers of developmental synesthesia. LW and ten non-synesthees completed synesthetic consistency and face-color priming tasks. LW’s face-color synesthesia met the criteria for consistency and he also displayed a larger congruency effect (incongruent – congruent) than controls, thereby reflecting that LW’s face-synesthesia also exhibits automaticity. 2C-B appears to function as a partial serotonin agonist, and the overdose may have triggered hyper excitability in LW’s visual cortex resulting in sustained color experiences that were eventually producing consistent and automatic associations with emotional faces, through consolidation over time.
Mapping the empirical territory between the growing research fields of ecopsychology and psychedelic therapy there is virtually no data on the relationship between the psychedelic experience and the apparent concomitant development of increased eco-consciousness, despite numerous anecdotal reports. In an anonymous online survey 150 psychedelic users reported on their use of psychedelics, their experiences in relation to Nature, and how their experience had changed their attitudes towards ecological issues. It was hypothesised that the majority of psychedelic substance users would report an increased connection with Nature and expanded eco-consciousness as a result of their experience, and that the use of psychedelics would generally increase rather than decrease eco-consciousness. It was also expected that specific types of substances would lead to specific types of transpersonal-type encounter experiences. The results were consistent with the hypotheses and are discussed in detail.
Peer-review Journal Articles
Psychedelic drugs reliably trigger experiences that closely resemble synaesthesia (Luke and Terhune 2013), a condition in which inducer stimuli will reliably and automatically elicit atypical concurrent experiences (Ward 2013). These transient episodes are considered controversial because they do not meet behavioural diagnostic criteria for developmental synaesthesia (Terhune et al. 2016). However, if these behavioural markers are attributable to the consolidation of synaesthetic associations over time (Terhune et al. 2016), they should be observed in cases of acquired synaesthesia. Here we report a case of drug-induced acquired synaesthesia (LW) that meets standard diagnostic criteria for developmental synaesthesia.
Rationale: Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterations in time perception has implications for its impact on conscious states and a range of psychological functions that necessitate precise interval timing. However, interpretation of this research is hindered by methodological limitations and an inability to dissociate direct neurochemical effects on interval timing from indirect effects attributable to altered states of consciousness.
Methods: We conducted a randomised, double-blind, placebo-controlled study contrasting oral administration of placebo with three microdoses of LSD (5, 10, and 20 μg) in older adults. Subjective drug effects were regularly recorded and interval timing was assessed using a temporal reproduction task spanning subsecond and suprasecond intervals.
Results: LSD conditions were not associated with any robust changes in self-report indices of perception, mentation, or concentration. LSD reliably produced over-reproduction of temporal intervals of 2000 ms and longer with these effects most pronounced in the 10 μg dose condition. Hierarchical regression analyses indicated that LSD-mediated over-reproduction was independent of marginal differences in self-reported drug effects across conditions.
Conclusions: These results suggest that microdose LSD produces temporal dilation of suprasecond intervals in the absence of subjective alterations of consciousness.
Papers
Multiple psychedelic drugs, particularly those targeting the serotonin system can elicit experiences, resembling those of developmental synesthesia. Although controversial, drug induced synesthesia can consequentially counter some of the existing theories of synesthesia. The study presents the case of LW who is a 29-year-old-man, experiencing multiple forms of synesthesia including day-color, sound-color, emotion-color, smell-color, and face-color synesthesia, following the ingestion of 70-80mg of 2C-B at the age of 22. LW’s face-color synesthesia is the strongest, particularly when faces convey particular emotional expressions. He perceives color as visuospatial co-localized with inducing faces (projector synesthesia). The study aim was to examine whether LW’s face-color synesthesia met the criteria for automaticity and consistency, which are the main markers of developmental synesthesia. LW and ten non-synesthees completed synesthetic consistency and face-color priming tasks. LW’s face-color synesthesia met the criteria for consistency and he also displayed a larger congruency effect (incongruent – congruent) than controls, thereby reflecting that LW’s face-synesthesia also exhibits automaticity. 2C-B appears to function as a partial serotonin agonist, and the overdose may have triggered hyper excitability in LW’s visual cortex resulting in sustained color experiences that were eventually producing consistent and automatic associations with emotional faces, through consolidation over time.
Mapping the empirical territory between the growing research fields of ecopsychology and psychedelic therapy there is virtually no data on the relationship between the psychedelic experience and the apparent concomitant development of increased eco-consciousness, despite numerous anecdotal reports. In an anonymous online survey 150 psychedelic users reported on their use of psychedelics, their experiences in relation to Nature, and how their experience had changed their attitudes towards ecological issues. It was hypothesised that the majority of psychedelic substance users would report an increased connection with Nature and expanded eco-consciousness as a result of their experience, and that the use of psychedelics would generally increase rather than decrease eco-consciousness. It was also expected that specific types of substances would lead to specific types of transpersonal-type encounter experiences. The results were consistent with the hypotheses and are discussed in detail.
Psychedelic drugs reliably trigger experiences that closely resemble synaesthesia (Luke and Terhune 2013), a condition in which inducer stimuli will reliably and automatically elicit atypical concurrent experiences (Ward 2013). These transient episodes are considered controversial because they do not meet behavioural diagnostic criteria for developmental synaesthesia (Terhune et al. 2016). However, if these behavioural markers are attributable to the consolidation of synaesthetic associations over time (Terhune et al. 2016), they should be observed in cases of acquired synaesthesia. Here we report a case of drug-induced acquired synaesthesia (LW) that meets standard diagnostic criteria for developmental synaesthesia.
Rationale: Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterations in time perception has implications for its impact on conscious states and a range of psychological functions that necessitate precise interval timing. However, interpretation of this research is hindered by methodological limitations and an inability to dissociate direct neurochemical effects on interval timing from indirect effects attributable to altered states of consciousness.
Methods: We conducted a randomised, double-blind, placebo-controlled study contrasting oral administration of placebo with three microdoses of LSD (5, 10, and 20 μg) in older adults. Subjective drug effects were regularly recorded and interval timing was assessed using a temporal reproduction task spanning subsecond and suprasecond intervals.
Results: LSD conditions were not associated with any robust changes in self-report indices of perception, mentation, or concentration. LSD reliably produced over-reproduction of temporal intervals of 2000 ms and longer with these effects most pronounced in the 10 μg dose condition. Hierarchical regression analyses indicated that LSD-mediated over-reproduction was independent of marginal differences in self-reported drug effects across conditions.
Conclusions: These results suggest that microdose LSD produces temporal dilation of suprasecond intervals in the absence of subjective alterations of consciousness.