Biology Magazine

Encultured Hallucinations

Posted on the 06 March 2012 by Cris

Hallucinations are a universal feature of human experience. This doesn’t mean that everyone has hallucinated, but everyone is capable of hallucinating. If hallucinations can be managed, the effects range from enlightening to fun. If hallucinations are uncontrolled, the effects range from psychosis to terror. In most cases, expectations are the key to management and control. This explains why all societies prescribe ways for coping with and categorizing hallucinations.

When contemplating hallucinations in American culture, we tend to think of only two: the psychotropic fun kind and the psychotic horrifying kind. This habitual binary is not a biological given but rather is a cultural construction. Hallucinations exist along a spectrum, and different societies experience and categorize them in different ways. This makes hallucinations the perfect subject for a psychological anthropology that examines the interplay of biology and culture.

Sensing the analytical richness of the field, Stanford professor Tanya Luhrmann has turned her attention to the social construction of sensory experiences in general and “non-rational” hallucinations in particular. She states that her current research goal “is to distinguish the different patterns of sensory experiences most commonly identified as divinely inspired and those most commonly identified as psychiatric symptoms, and to understand those patterns in historical and social context.” To this end, Luhrmann is studying American evangelicals and psychiatric patients. As someone raised in an evangelical home, I can bear witness to the rife possibilities.

In the 2011 Annual Review of Anthropology, Luhrmann published a primer (open) on sensory overrides or hallucinations. She begins by asking why hallucinations occur: What is happening in the mind? Although there is no firm consensus, most agree that hallucinations are tied to perception and what is known as “reality monitoring.” This perspective views the mind not as a passive recipient of direct stimuli (the Hume-like model), but as an active agent which filters, interprets, and constructs experience from stimuli (the Kant-like model). Because we know the latter model is far closer to being correct, hallucinations become explicable:

From the reality monitoring perspective, hallucination-like experiences occur not because there is necessarily something wrong with one’s mind, but because one interprets something imagined in the mind as being real in the world. The most plausible mechanism here is that we constantly experience perceptual “breaks,” which we repair below the level of our awareness, either by filling in a perceptual break from its surrounding perceptual field or by interpreting the break with prior knowledge (e.g., the way being told that strange sounds are English can change the way one hears them). Hallucinations probably occur in the process of repair, and the cause is likely more often perceptual bias than perceptual deficit.

In the case of perceptual deficits, we make things cohere by creatively filling the gaps. In other contexts, this is called confabulation. In the case of perceptual bias, a need or yearning is being fulfilled: “Someone who perceives an ambiguous noise is more likely to interpret it, someone who needs an answer is more likely to listen for one, and someone who believes that an answer can be heard is more likely to hear one.” While this is a useful analytical distinction, it seems more likely that these work in tandem: when we experience perceptual gaps we fill them with perceptual bias. It’s a powerful process capable of generating hallucinations.

Encultured Hallucinations

Given our tendency to categorize hallucinations either as psychotropic fun or pathological delusion, we should be mindful that hallucinations needn’t be either. There are ranges of hallucinations and these may exist along a continuum. You don’t need to take drugs or be mad to hallucinate.

Knowing this, Luhrmann identifies three patterns of hallucinations that appear in all societies. The first and most pervasive is Sensory Override, in which people “experience a sensation in the absence of a source to be sensed.” The paradigmatic example is the hearing of a voice even though no one is present or no one has spoken. Although the hearing of non-existent voices is common across cultures and has been attributed to all manner of spirits, gods, ghosts, and other imaginaries, in the US it is often reported by charismatic Christians who believe God is talking. Luhrmann’s research links this experience to an attentional state which dampens external stimuli and amplifies internal arousal:

Absorption is the capacity to become focused on the mind’s object — what humans imagine or see around them — and to allow that focus to increase while diminishing attention to the myriad of everyday distractions that accompany the management of normal life. It is the mental capacity common to trance, hypnosis, dissociation, and much other spiritual experience in which the individual becomes caught up in ideas or images or fascinations.

The second hallucination pattern, Psychosis, is the one we often associate with hallucinations. It’s the pathological, distressing, and debilitating kind. The third, which Luhrmann calls Joan of Arc, might be more aptly called Prophet. People exhibiting this pattern may hear voices for extended periods of time and intensely hallucinate on occasion but otherwise seem normal. I tend to think this pattern is related to psychosis and falls on a pathological continuum. It is probably a less severe form of psychosis, analogous to high functioning autism on that spectrum.

Throughout her review, Luhrmann emphasizes that hallucinatory experiences are shaped and constrained by learning and expectation. Hallucination experiences are socially constructed and culturally patterned. Nowhere is this more true than in the realm of the supernatural and religious, where hallucinations are highly valued. Luhrmann calls this “Spiritual Training” and comments:

It is also true that spiritual training may make sensory overrides more likely. Inner sense cultivation — and mental imagery cultivation, in particular — is at the heart of shamanism and is central to many spiritual traditions….[T]wo dominant forms of mental techniques in effect train the human mind to experience the supernatural: techniques that focus attention on the inner senses and those that train attention away from thought and sensation. Examples of the former include shamanism, Tibetan vision meditation, and the Ignatian spiritual exercises; examples of the latter are Zen meditation and Centering Prayer.

Both train the attention, and they probably train the capacity for absorption. Although the psychological literature is largely silent about whether these training techniques generate sensory overrides, the ethnographic and historical literature strongly suggest that inner sense cultivation produces sensory experiences that are interpreted as signs of the supernatural.

For reasons that may be related to her fieldwork with Christian informants, Luhrmann doesn’t mention the Christian experience. Doctrinal differences aside, Christianity encourages and trains these techniques too. While it is possible that everyone who experiences sensory override is in touch with something ethereal, the more parsimonious (and experimentally verifiable) explanation resides in the biology and culture of the mind.


Luhrmann, Tanya. (2011). Hallucinations and Sensory Overrides. Annual Review of Anthropology, 40, 71-85 : 10.1146/annurev-anthro-081309-145819


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