Red visual stimulation in the Ganzfeld leads to a relative overestimation of duration compared to green.
Sebastian L. Kübel, Henrike Fiedler, Marc Wittmann
PsyCh Journal February 2021 DOI: 10.1002/pchj.395 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Balanced within-subject experiment Peer reviewed |
|---|---|
| Sample size | 67 |
| Population | Participants with some prior meditation experience |
| Intervention | Brown noise |
| Duration | Two 25-minute Ganzfeld sessions |
| Measures | Self-Assessment Manikin (SAM), visual analog scales (VAS), duration estimation |
| Topics | Altered states of consciousness |
| Keywords | Ganzfeld Color effects Perceptual deprivation |
| Key findings | Red-light Ganzfeld sessions were estimated as lasting longer than green-light sessions (mean 23.1 vs. 19.8 minutes), and this effect was fully mediated by higher arousal during the red session. Green sessions reduced arousal, while red sessions left participants feeling less emotionally positive. The authors recommend green light for relaxation in Ganzfeld research on altered states of consciousness. |
Abstract
A Ganzfeld is a homogenized visual and auditory perceptual field which can induce altered states of consciousness (ASC; Metzger, 1929; Schmidt & Prein, 2019). Using a balanced intrasubject design, we compared participants' experience during two differently colored (red, green) 25-min Ganzfeld sessions with brown noise as acoustic stimulation. Participants were exposed to the colored visual field through commercially available goggles and to brown noise over headphones. We selected 67 participants with some prior meditation experience to increase the probability that they would engage meaningfully with this specifically restricted stimulus situation. We tested the functional components of the standard cognitive model of time perception (Zakay & Block, 1997) in a path analysis for direct (red vs. green light) and indirect effects (arousal, attention) on subjective duration and perceived passage of time. Subjective arousal and valence states were measured using the Self-Assessment Manikin (SAM). The amount of attention directed to time and the perceived passage of time were rated with standard visual analog scales (VAS). Participants also estimated the duration of each Ganzfeld exposure. The session with the red visual field lasted significantly longer than did the green session (μred = 23.1 min; μgreen = 19.8 min). After the green session, participants rated their arousal level to have significantly decreased; after the red session, individuals on average felt emotionally less positive. Multiple path analyses revealed that the effect of color on estimated duration is completely mediated through higher arousal levels during the red Ganzfeld session. In turn, the higher arousal level generates a longer subjective estimate of duration. For induction of relaxation in studies probing altered states of consciousness employing the Ganzfeld technique, we recommend using the green light.
Comparable studies
Other experimental studies on altered states of consciousness, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| The Standardized Psychometric Assessment of Altered States of Consciousness (ASCs) in Humans Healthy subjects in six countries | 1998 | Experimental and field study | n = 1,133 |
| TMS-EEG and resting-state EEG applied to altered states of consciousness: oscillations, complexity, and phenomenology. | 2023 | Experimental study | |
| A Test of the Psychedelic Model of Altered States of Consciousness | 1976 | Experimental study with comparison groups | |
| Neural Correlates of Non-ordinary States of Consciousness in Pranayama Practitioners: The Role of Slow Nasal Breathing Experienced meditators | 2022 | Within-subjects comparison | n = 12 |
| Increased spontaneous EEG signal diversity during stroboscopically-induced altered states of consciousness Healthy adults | 2019 | Experimental study |
Citations in the library
Cited by 9
- Altered states phenomena induced by visual flicker light stimulation PLoS One July 1, 2021
- The Altered States Database: Psychometric data from a systematic literature review. Scientific Data November 23, 2022
- Classification schemes of altered states of consciousness. Neuroscience & Biobehavioral Reviews August 1, 2025
- The neurobiology of altered states of consciousness induced by drumming and other rhythmic sound patterns. Annals of the New York Academy of Sciences July 16, 2025
- Update of the Altered States Database (ASDB): 2022-12-31 February 22, 2023
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