Enhancement of Creative Expression and Entoptic Phenomena as After-Effects of Repeated Ayahuasca Ceremonies

This was a naturalistic, repeated-measures study conducted among self-motivated participants of ayahuasca ceremonies in Florianópolis, Brazil. Forty volunteers met inclusion criteria and completed the figural components of the Torrance Tests of Creative Thinking (TTCT) prior to the first ceremony and again 24–48 hours after the final session of a two-week series. A comparison group of 21 control participants (undergraduate students and staff recruited in Helsinki and Budapest) completed the same TTCT figural tasks twice, two weeks apart, without ingesting ayahuasca. The investigators obtained written informed consent and reported institutional ethical clearance for use of the test. Inclusion criteria for the ayahuasca group required prior psychedelic experience (at least three lifetime occasions), intention to stay for two weeks, and planned ingestion of at least 50 ml of ayahuasca in at least four sessions. Exclusion criteria included personal history of psychiatric or neurological disorder, recent alcohol or illicit drug use, lifetime substance dependence, extreme BMI (<18.5 or >30 kg/m2), significant head injury, and inadequate subjective experience during the ceremonies. From an initial pool of 48 candidates, eight were excluded for low dose, suboptimal experience, or insufficient session attendance, leaving 40 experimental subjects (17 males, 23 females; mean age 30.9 ± 7.7 years) and 21 controls (10 males, 11 females; mean age 27.1 ± 8.6 years). Ayahuasca sessions followed traditional ceremonial practice: participants observed dietary restrictions for two weeks and drank the brew every second or third day (four or five doses over the two weeks). On ceremony nights subjects fasted from 14:00, ingested self-chosen doses of at least 50 ml around 20:00, and rested supine with lights off for four hours post-ingestion. Mean total intake across the two-week period was 583 ± 315.8 ml; alkaloid concentrations from the same source had been analysed previously. The subjective intensity of each session was rated the following morning on a five-point Likert scale. Only the figural TTCT tasks were scored because participants spoke different native languages. The figural tasks comprised a blank-circle-use task (35 circles) and a figure-completion task (10 abstract shapes) with timed performance. Two independent raters blind to group membership scored each response for fluency, flexibility, and originality using standard TTCT procedures; interrater Cronbach's alphas exceeded 0.77. Because fluency strongly influences flexibility and originality, relative scores (relative flexibility and relative originality: ratios of summed flexibility or originality to summed fluency) were calculated. The number of ‘‘highly original’’ solutions (originality score > 0.90) was also tabulated as a primary creativity index. Separately, the authors coded phosphenic responses in the drawings according to six entoptic categories derived from prior work (grid/lattice, parallel lines, dots/flecks, zigzags, nested curves, filigrees). Each phosphenic instance was scored by two raters; the phosphenic score had Cronbach's alpha = 0.81. Statistical analysis used repeated-measures ANOVA (IBM SPSS v19.0) to test group-by-time effects on the specified creativity and phosphenic variables, with Bonferroni post hoc comparisons when interactions were significant. Age was entered as a covariate where relevant. Qualitative and nonparametric comparisons used Pearson's chi-square and Kolmogorov–Smirnov tests. A separate team administered the brew and tests, blind raters scored the tests, and a third party conducted the statistical analyses.

Descriptive data: the ayahuasca group (N = 40) had mean age 30.9 ± 7.7 years and included 17 males and 23 females; the comparison group (N = 21) had mean age 27.1 ± 8.6 years with 10 males and 11 females. Twenty-five ayahuasca participants attended four sessions and 15 attended five sessions during the two-week period. On standard TTCT indices, repeated ayahuasca ingestion did not change overall fluency, relative flexibility, or relative originality. However, the number of highly original solutions increased significantly after the two-week ceremony series. For the blank-circle-use task the mean number of highly original solutions rose from 0.7 ± 1.01 pre-ayahuasca to 1.7 ± 1.04 post-ayahuasca (ANOVA F1,59 = 13.8, p < 0.0005; Bonferroni post hoc p < 0.0001). For the figure-completion task highly original solutions increased from 1.1 ± 1.06 to 2.9 ± 1.88 (F1,59 = 17.2, p < 0.0005; Bonferroni post hoc p < 0.0001). Baseline measures of creativity did not differ between groups, and entering age as a covariate did not alter the significant post-test increases. Phosphenic responses also increased after the ceremony series. Mean phosphenic scores were 5.2 ± 5.86 pre-ayahuasca versus 7.8 ± 6.90 post-ayahuasca, compared with controls' retest mean of 0.8 ± 1.12 (ANOVA F1,59 = 4.7, p < 0.05). Bonferroni post hoc tests indicated significant differences between post-ayahuasca and pre-ayahuasca (p < 0.01) and between post-ayahuasca and controls' retest (p < 0.0005). Notably, the ayahuasca group already exhibited more phosphenic solutions at baseline than controls (5.2 ± 5.86 vs. 1.6 ± 2.16; p < 0.05). The ayahuasca participants also reported more psychedelic experiences during the six months preceding the study than controls did (1.1 ± 1.2 vs. 0.1 ± 0.4; p < 0.005). Interrater reliability for creativity scoring exceeded 0.77 and for phosphenic scoring was 0.81.

Frecska and colleagues interpret their findings as evidence that repeated ritual use of ayahuasca is associated with a specific after-effect on visual originality and with increased entoptic (phosphene-like) activity once the acute intoxication has subsided. They highlight that, while general creativity indices such as fluency and relative flexibility did not change, the number of highly original solutions on figural TTCT tasks increased significantly after the ceremony series. The increased phosphenic activity after repeated ingestion is presented as consistent with prior reports that psychedelics evoke simple geometric visual phenomena which can persist beyond acute effects. The authors stress the naturalistic strength of applying a standardised creativity test in a context of repeated psychedelic exposure, but they acknowledge several important limitations. Most prominently, the study cannot separate pharmacological effects of ayahuasca from the ceremonial set and setting because control subjects did not undergo an equivalent ritual environment, diet, or schedule; thus conclusions apply to the combined ‘‘ceremony’’ context rather than to the drug in isolation. The mixture nature of ayahuasca is noted as a further limitation: variable concentrations of DMT and harmine and the presence of tetrahydroharmine complicate dosing control and interpretation, and the extraction does not allow direct blood-level monitoring. The authors also consider the alternative explanation that creative people self-select into ayahuasca rituals; they note, however, that baseline creativity scores did not differ between groups, which weakens this self-selection argument though it does not eliminate it. Speculative neuropsychological remarks are offered: a model attributing idea generation to frontal regions, evaluation/editing to temporal regions, and goal-oriented drive to limbic structures is invoked to suggest possible mechanisms, and the authors cite evidence that ayahuasca increases frontal and paralimbic blood flow during acute effects. They further note pharmacokinetic suggestions that DMT may persist in the brain for up to about a week and that long-lasting visual after-effects might reflect hyperexcitability of lower visual pathways. Finally, the study is placed in a broader ethnopharmacological and art-historical context: the authors propose that entoptic phenomena warrant study as potential intrinsic sources of artistic motifs and suggest that their findings provide a foundation for future controlled research on psychedelics and creativity, while emphasising the need for placebo-controlled, ethnically comparable designs that replicate ceremonial conditions if pharmacological and contextual factors are to be disentangled.