Sensory deprivation, Nimitta and Jhana


I believe you may not have correctly characterized the view that is critical of DJ. What I’ve read of Thanissaro Bhikkhu seems to imply that DJ is all too similar to what he terms “the state of non-perception,” and he holds this state to be wrong concentration:

The state of non-perception comes about from making your focus extremely one-pointed and so refined that it refuses to settle on or label even the most fleeting mental objects. You drop into a state in which you lose all sense of the body, of any internal or external sounds, or of any thoughts or perceptions at all. There’s just enough tiny awareness to let you know, when you emerge, that you haven’t been asleep. You can stay there for many hours, and yet time passes very quickly. Two hours can seem like two minutes. You can also program yourself to come out at a particular time.

This state does have its uses—as when you’re in severe pain and want some respite from it. As long as you recognize that it’s not right concentration or release, the only danger is that you may decide that you like hiding out there so much that you don’t want to do the work needed to go further in the practice.

I don’t know whether he’s right, but I do know that I would be unable to differentiate this description from what I infer DJ to be like. (Nor is his “easy” jhana all that easy, for that matter.)


Easy-jhana as in easy, relatively speaking, when compared to the other view. Not easy as in everyone being able to acheive it effortlessly. Far from it.

I think your quote is quite interesting, because awareness during deep sleep can be a side effect of decades of meditation, particularly techniques using a mental sound, such as a mantra. I know of people who are never unconscious, even during natural deep sleep (anesthesia is the exception). It never even occurred to me to label this phenomenon jhana, but if it is, that is very interesting.


There’s no mention of a mindfulness whilst asleep meditation in Satipatthana, so I take that to mean that such a state is not conducive to development.


Hi @justletitgo,

I read the paper before: it’s pretty interesting that sensory deprivation leads to these perception-of-light experiences. It makes sense, since at that stage of meditation, your mind is starting to separate from the physical realm.

Where I would urge some caution is to note that science generally has a materialist bias i.e. that everything has a material-cause. The danger is to then look for some material-based crutch, e.g. some form of drugs to trigger certain neural pathways, even triggering “lights” or “jhana”-like experiences etc. This sort of approach makes sense only in a fully materialist world.

However, if (as is heavily implied in the suttas) the mind is separate but closely linked to the body, and if it is possible for the mind to exist separately from the body, then this materialist approach might be counterproductive in the longer-run, because the materialist approach only addresses the material cause but not the mind. The Buddha’s analogy nama-rupa (the objects of consciousness) and consciousness are like two sheaves of reeds leaning against each other is apt here: so a materialist approach will only address one sheaf of reeds (nama rupa) but not the other.

On the fighting that happened in MN128, you could listen to Ajahn Brahm’s sutta talk here (Deeper Dhamma Podcast - MN128 Upakkilesa Sutta – Imperfections | Ajahn Brahmavamso | 26 February 2012 | Free Listening on Podbean App). If I remember correctly, it was about a minor matter that blew up: after the Buddha left, the issue was settled when the lay community stopped feeding the monks, which removed the fuel for their bodies as well as the fuel for the conflict… :wink:

With metta,


Hi pjteh,

I don’t read a separation between body and mind in the western sense in the suttas. I also don’t understand the idea of nama-rupa as “objects of consciousness”. That would be form, …, mind objects, wouldn’t it? Perhaps I’m missing something, but to me there are three ways of analysing experiential processes in the suttas: aggregates, sense bases + objects, and nama-rupa + consciousness. They tend to be used in different contexts, so the aggregate classification is commonly used in discussions of not-self, whereas the sense base classification in discussing craving.

In fact, one could argue (this is not an idea original to me!) that the suttas don’t have a mind-body duality in the western sense, and that, ironically, the materialist view has also removed the mind-body duality (but probably not in the correct way…).

But this is getting a little off topic. The sensory deprivation tanks obviously remove the objects of sight and hearing, etc, but obviously not mind objects…


Could you provide references for these writings and talks? I’d love to read and listen…


This article says:

that take the fourth jhana as their point of departure. Texts drawing on the Pali Canon have mapped out these descriptions, listing the factors that go into each jhana or formless attainment. Advanced Practice | With Each & Every Breath.

What does it mean to be formless, if form cannot be felt in the form (rupa) jhana, isn’t clear conceptually.


Indeed. And I also feel like “neither perception nor non-perception” is all too close to “paying attention only to mental events without awareness of external perceptions.” It’s not simply that there are “easy” and “hard” models of jhana. It’s that the various parts all seem to be presented in different orders depending on whom one asks.

But: One thing that many teachers agree upon all across the range of views on the topic is that individual experiences may not line up too well with the canonical descriptions. This at least is a reason for some hope, and possibly for some reconciliation. It means that one person’s explanation of the canon in terms of their own personal experience (or of someone else’s) may not be the same as another’s. It’s a remarkably difficult interpretive problem.


I think we can draw some robust conclusions from the EBTs themselves :slightly_smiling_face:. There is a clear progression of the ability of certain experiences ceasing.


One possibility might be that the state of neither perception nor non-perception is supposed to be a state without a sense of self. Since there is no sense of self, then whatever phenomena are present in that state of consciousness are in some sense perceived since they are part of the flow of that individual’s perceptions, but are in another sense not perceived, since the individual no longer possesses an underlying sense of being something that is perceiving the percept.

The formless states are not mentioned in all of the sutta accounts of right samadhi. It is possible that they are just different states taught, or allegedly taught, by different meditation masters of the time just before or after the Buddha, and were incorporated into the tradition later. They might not actually comprise a “progression” as they appear in the suttas. Maybe they are just different states which are all equally “deep”, or maybe they are just different names which diffferent teachers gave to the same state.


Well if they were incorporated that means they are in line with the dhamma and useful practice. Not every wholesome thing has to be discovered entirely by the Buddha according to the EBTs.

Jhana and attainments are not states with insight in-built, but rather samatha samadhi. They are ‘peaceful abidings’. They require insight practice to convert them to nibbana.


My first book, A Swift pair of Messengers, dealt with these topics in detail. I’ve done a lot since then as well, but you’ll have to search down my retreat talks. I don’t like to talk about jhanas and other such advanced topics too much in daily Dhamma talks.

Rūpa includes material properties apprehended by the mind, such as light or space, and is commonly used in the suttas for the light seen in meditation, which later texts refer to as the nimitta. This is what rūpa means in rūpajjhana.


Dear Bhante, I am imagining how nice it will be for all the great Ajahn today, who see light or who never see light in their meditation, can gather with the world great neurologist to find out the real mechanism behind why one perceive light when the eye sensory is cut off. I think there are lots of meditators practice very diligently for years but still never see lights as compose to some others who can just in their first retreat! Some teachers said that this is due to their past life parami, but other than this reason which a meditator has no control of (pass life parami), could it be due to they are having a different visual cortex as compare to those who see lights?

But I am just imagining as this can hardly happen, right?

Also, other religion practicing meditation are giving different kind of meanings for lights seen in meditation: Meditation & Meaning of Lights |

Moreover, sometime text like below create more confusion too! :wink:

Stillness Flowing - The Life and Teaching of Ajahn Chah (by Ajahn Jayasaro)
On one occasion, a monk came to ask Luang Por why it was that, despite
putting great effort into his meditation, he had still never seen the lights
and colours that others claimed to see. Luang Por replied:
See light? What do you want to see light for? What good do you
think it would do you? If you want to see light, go and look at that
fluorescent lamp. That’s what light looks like.

Don’t be attached to visions or lights in meditation, don’t rise or fall with them. What’s so great about brightness? My flashlight has it. It can’t help us rid ourselves of our suffering.

Source: Questions and Answers - Ajahn Chah
Is it necessary to be able to enter absorption in our practice?

No, absorption is not necessary. You must establish a modicum of tranquillity and one-pointedness of mind. Then you use this to examine yourself. Nothing special is needed. If absorption comes in your practice, this is OK too. Just don’t hold on to it. Some people get hung up with absorption. It can be great fun to play with. You must know proper limits. If you are wise, then you will know the uses and limitations of absorption, just as you know the limitations of children verses grown men.

With Metta


Mat, the absence of a sense of self is not necessarily the same thing as the sense of an absence of self. The state itself might not be accompanied by insightful reflection on on the nature of the state, but it could be that after meditators emerge from it, they are then able to describe its nature, and recognize that there was no sense of self present in it.


When vitakka and vicara disappears in the second jhana there’s no sense of self after that anymore. Rather this would be a disappearance of the whole world. However no one would think the world actually disappeared.


I agree. In some cases, it can be a hindrance if it leads to the belief that this minimal consciousness is permanent, and thus a refuge. However, I also know someone who experienced shutdowns of this minimal consciousness. That was initially quite frightening to this person, because consciousness knew it had been gone, and hence it felt as if “I am unreal”. That person is now a dhamma practitioner and no longer afraid.


I have used a sensory deprivation tank before. I actually found it sort of difficult to remain mindful. I think the way of meditation we are used to in formal sitting offers a gradual and linear deepening, while floating in the tank is too sudden to adjust to.

Though, I’m sure with practice it might be beneficial.


Does this arise due to a process of Samatha (tranquility) or vipassana (insight)


What does this mean? Are they suddenly awake but are supposed to be subtly asleep?