Hearne, K. A light-switch phenomenon in lucid dreams. Journal of Mental Imagery, 5 (2), 97 - 100. 1981.
A previous extensive study of LDs revealed that some accounts of both NDs and LDs referred to an inability of the dreamer to switch on an electric-light in the dream scenery. This observation was pursued by giving the task to a number of LDers in order to ascertain the reliability of such reports.
Eight LDers (five females, three males) were requested to attempt to switch on an electric-light in a LD and report what happened. Subjects were naive as to the purpose of the experiment.
Five of them couldn’t turn the light on. The sixth couldn’t even find the switch. The seventh only got a sparking and flickering orange bulb. Only the eighth was able to switch the light on, but only after she covered her eyes first.
Subjects can routinely carry out pre-sleep instructions in LDs, yet the task of switching on a light presents a strangely consistent difficulty. Its widespread nature indicates a possible important limitation in the “dream engineering” process. The eighth case, who could switch on a light after covering her eyes and abolishing the imagery, is revealing when considered with the experience of another person who reported that a light may be switched off first, and then on, but not the other way round. This shows a possibility exists that there’s a ceiling limit on brightness in the dream imagery at any point (but this ceiling may vary over time), and any attempt to violate that level by manipulating the dream results in rationalized avoidance of the intended situation. If so, it would suggest that an autonomous dream-producing process operates, which has to maneuver the dream within such limitations of imagery. Other less plausible explanations are:
- The phenomenon reflects the operation of a “sleep-maintaining process” which avoids dream scenes such as a light suddenly switching on, since that might normally waken a sleeping person irl (although a light can switch on from a reduced imagery as with the eighth case).
- The phenomenon may symbolize the “powerlessness” or “lack of energy” of the sleep state (although its apparent specificity does not support that notion).
Moss K., Performing the light-switch task in lucid dreams: A case study. Journal of Mental Imagery 1989 Sum, Vol 13(2), pp. 135-137.
Hearne (1981) found that subjects were unable to turn on an electric light in a LD and concluded that this task was beyond the ability of the LDer (see above). In a follow-up study Hearne (1982) again reported this inability. He then hypothesized that there existed “a varying ceiling-level of imagery brightness”. Tholey (1983) also reported that subjects were unable to perform the light-switch task. However, he did find that some subjects were able to gradually increase illuminance by other methods.
The author himself was the subject of a three-month investigation during which he had 70 LDs. In a selected portion of them, he attempted the light-switch task or the control task of increasing luminosity by any method other than turning on an electric light. The subject reports a history of having 830 LDs since 1979. In some of them, he was able to gradually and suddenly increase luminosity by a variety of methods. However, prior to the current study, he never attempted to turn on an electric light in a LD.
The light-switch task was successfully performed in 11 out of 15 LDs. In five dreams, the resulting luminosity increase exceeded current and all previous luminosity levels for that dream. A total of 33 different lights were attempted. The light turned on during 20 of these attempts. On two occasions, the light turned on but was not sustained. The light had little effect on the environment four times. The other positive results were sudden, bright, sustained and effective. All five attempts to turn the light back off were successful.
In eight LDs the subject attempted to increase luminosity by a method other than switching on a light. In all eight LDs, luminosity was increased above the previous maximum level. In four of these dreams, luminosity was increased a second time. These results included both gradual and sudden increases. Examples of intentional luminosity increases included looking at a light source, opening a curtain and walking outside into the sunlight.
Several factors were conducive to successfully performing the task. In dreams that initially had a negative result, the subject was able to achieve a positive result if he persisted in attempting or changed to a different light switch. Another important factor was to find an angle of view that best facilitated the flow of action (switch to light to scene). Therefore, a view that included the switch and light in close proximity would be the most favorable to make the test work. In dreams where they were separate, this situation could be approximated if they were viewed alternatively. If only the light was viewed, it was helpful to have a good tactile sensation of the switch. Other views, such as looking only at the switch or at some part of the scenery, were especially vulnerable to failure. A good strategy was to attempt a luminosity increase by another method and then decrease it back to the baseline level prior to attempting a light-switch trial. Practice, motivation, frequency and the waking study and attention to the task may also be factors.
So despite encountering some problems, the subject was able to successfully complete the light-switch task. The assignment of finding and operating the switch and pairing it with the light chance can be difficult. However, other tasks can be performed in LDs with appropriately paired results. A voluntary sudden increase beyond an established luminosity level may be difficult at times but is not impossible, as indicated by the results of the control task. Hence the light-switch task involves a number of problems, none of which are impossible, but which together make it difficult.