A replication of “The Ganzflicker experience” with a sample size of 1587

“Ganzflicker” is a full-field, rhythmic visual flicker, using a technique that is known to elicit pseudo-hallucinations and altered states of consciousness (Allefeld et al., 2011; Bartossek et al., 2021; Schwartzman et al., 2019; Sumich et al., 2018). In a recently published study (Königsmark et al., 2021), we found individual differences in the likelihood of reporting visual pseudo-hallucinations, as well as different features of pseudo-hallucinations, while observing 10 minutes of continuous red-and-black flicker at 7.5 Hz, termed “Ganzflicker”. In a post-experience questionnaire of 204 responses, we found extremely strong evidence that the likelihood of experiencing complex and vivid pseudo-hallucinations is related to self-reported visual mental imagery vividness. Specifically, people with no visual imagery (or, at most, dim or vague imagery; aphantasia distribution) are much less likely to experience vivid and complex pseudo-hallucinations than people with moderate-to-vivid visual imagery (imagery distribution).In this commentary, I present an updated analysis of Ganzflicker questionnaire responses, due to a significant increase in the number of new data points collected (N = 5553), influenced by a recent article published in the popular media (Reeder, n.d.). In this new analysis, environmental variables were found to play a role in pseudo-hallucination proneness, particularly concerning whether participants viewed the Ganzflicker on a computer or mobile phone. This suggests that the level of visual immersion increases the likelihood of anomalous perceptual experiences. I also found extremely strong evidence that pseudo-hallucination proneness differs between people with a completely blind mind’s eye (imagery vividness rating = 0) compared to people with imagery, regardless of imagery vividness rating (ratings 1-10). This suggests that there are sometimes important distinctions between having low imagery and no imagery. I additionally found differences in the reported complexity and vividness of pseudo-hallucinations between people belonging to the aphantasia distribution (vividness ratings from 0-3) and imagery distribution (vividness ratings from 4-10), replicating previous results. Finally, I found that people belonging to the imagery distribution are more likely to see more frequent pseudo-hallucinations for a longer duration than people from the aphantasia distribution. In sum, I replicated the core result of the previous paper in a dataset that is orders of magnitude larger than the original.

Stylized and photographic eye images do not increase charitable donations in a field experiment

The effects of watching eyes upon prosocial behavior have been explored in various contexts, for example, in relation to charitable donations, honor-system payments and littering. Whilst studies have explored the effects of both photographic and stylized eyes upon prosocial behavior, no study, to our knowledge, has compared stylized eyes to photographic eyes. Here we explored the effects of stylized and photographic eye images upon prosocial behavior assessed via charitable donations in a ‘free cakes’ field experiment. Charitable giving was assessed under six eye image conditions, three stylized eye images (evil eye, eye of Horus, all-seeing eye), one photographic eye image (human eye image) and two control images (geometric shape control and blank control). No difference in the amount of money donated was found between any of the eye image conditions. These results suggest that watching eyes, whether stylized or photographic, are not effective at eliciting prosocial behavior via charitable giving. However, further study contrasting single and paired eye imagery, and exploration of the effects of stylized eye imagery in deterring littering and crime, would be beneficial.