What do you see when you meditate? Is it the back of your eyelids, a boring spot on the floor just a few feet in front of you? Or is it perhaps something more startling, like little pinpricks of light, or a sense that the world is glowing?
If you have seen those lights, don’t worry; you’re not hallucinating. Or rather, you are hallucinating, in a very strict sense of the word, and that may indicate just how far your meditation practice has progressed.
Granted, the evidence that meditation may induce these minor visual hallucinations is (pun intended) light. Members of Willoughby Britton’s lab – best known by me for demonstrating that meditation is not a purely golden panacea – interviewed a few dozen experienced meditators, chosen specifically because they had experienced something “significant, unexpected, [or] challenging” at some point in their meditation practice, about those significant experiences. A third of those meditators (nine in all) spontaneously mentioned light in some form, either as spots like starbursts or “Christmas lights”, or as a general shimmering or brightening of their visual field.
A few glimmers of light during meditation by some subset of experienced practitioners might seem like a trick of the eyes, something we can just as easily get from staring too hard at a computer screen, nothing worth getting worked up about. But the theory proposed to explain those lights is fascinating: essentially, that meditation may be a subtle form of self-induced sensory deprivation.
We know that sensory deprivation can cause similar experiences of seeing flashes of light (among other, even more extreme hallucinations). Neuroscientists think this is due to a quirk of our neurons. Normally, when we see something, neurons in the visual areas of the occipital lobe (toward the back of your head) become active, processing the information from our eyes; these neurons are so specific about what they respond to that it is even possible to “read minds” and identify what someone is seeing based on their occipital lobe activity. When these visual neurons haven’t been active in a while, though – as when you are in a very dark room, or wearing a very good blindfold – they become hypersensitive and activate for no reason in particular. (I think of it as a quick systems check – a paranoid neural engineer wanting to make sure that the failure really is out there in the world and not here in the brain’s equipment).
Although meditators don’t usually wear a blindfold, or sit in a dark room, we are in many ways deliberately trying to limit the activity in the visual area of our brain, along with our other senses. We sit in silence, in a still position, holding a “soft gaze” at some uninteresting spot on the floor; this means there is very little sensory input to be had. And what sensory input there is, we try to ignore, because we are trying to focus our attention on something else (usually, the breath), and so are inattentionally blind to everything else. An experienced meditator might easily reach a state where little to no information from the eyes is being processed…leading those neurons to run that systems check, creating a hallucination of light.
Even a mild self-induced sensory deprivation experience is no easy feat, and would most likely result from a very effective meditation session in which the attention was on the breath, and so far away from the visual experience that any input from the eyes was barely being processed. It would be a sign that you “made it” as a meditator – and although many meditators might eschew the very idea of meditating to “make it” to anything, scientists who study meditation might leap at the chance to identify skilled meditators through something other than mindfulness scales, brain scans, or just the number of years of meditation practice.
The most important message, though, may be the fact that Willoughby Britton’s lab is the first to explore the dancing lights of extreme meditation because those lights were mentioned in Buddhist texts.
Contemplative science and mindfulness have become mainstream in part because they are secular; attention-training activities that have the potential to alter the neurological default network are much more palatable to modern psychologists than religious practices with overtones of mysticism. The very first scientists to consider meditation, years ago, may have been fully versed in the Buddhist traditions behind them, but those ideas have been filtered out of the scientific literature. In some ways its impressive that meditation has managed to catch fire and remain effective when isolated out of its usual Buddhist context. At the very least, though, this isolation costs us information. Buddhist tradition mentions nimitta, peculiar visual experiences that result from mastering meditation, and other nyans, or experiences of meditation, that led interviewers to make note when meditators mentioned light…and a new perspective on what is going on in our brains during meditation was born. Perhaps it’s time for more psychologists and neuroscientists to dust off some religious texts, to take advantage of the history behind the experience we’re studying.
Lindahl JR, Kaplan CT, Winget EM, & Britton WB (2014). A phenomenology of meditation-induced light experiences: Traditional buddhist and neurobiological perspectives. Frontiers in Psychology, 4. PMID: 24427148