The Anatomy of Consciousness by O’Shaughnessy


I will briefly sketch O’Shaughnessy’s view of the anatomy of consciousness and raise some questions. For “anatomy” here we can read “structure.”

The central part of the approach asks a question about consciousness and its opposite. Consider the following analogy. There is only one way of being undiseased: not having any diseases. If there were only one disease, there would be only one state of being ill: it would be having that disease. In reality, there are many diseases and therefore many ways of being ill.

Is the pair consciousness/unconsciousness more like diseased/undiseased in a world with one disease or many? In other words, are their ways of being conscious in the same way as there are ways of being unconscious? It seems there are. So what are the states of consciousness?

Privative Opposite

All the states of unconsciousness are privative derivatives of consciousness i.e. they lack consciousness entirely.

Q: Why should we not say instead that all states of consciousness are privative derivatives of unconsciousness? More plausibly, could not unconsciousness come in degrees instead of consciousness coming in degrees? Could we not generate states of consciousness by adding several powers – experience, reason etc. – to the zero state of unconsciousness rather than in the direction of deleting powers, as O’Shaughnessy suggests?

Properties Of Unconsciousness

There are three negative properties of consciousness. Firstly, it has no object. This is shown by the contrast between `he was conscious’ and `he was conscious of a faint rustling’. Only in the latter usage is there an object. Consciousness proper figures only in the former usage and there it is more the arena for experience.

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Secondly, it does not have mental origins. Consciousness arises in the brain and whether it is present or not is decided by the brain and not by us or our judgment – since we have no choice about whether we become awake or not, short of setting an alarm clock. We may likewise have some choice about whether we become unconscious in that we can try to stay awake, but only for a limited period. O’Shaughnessy uses this to argue against consciousness having mental origins, presumably because he thinks that the mental is the location of our choice and judgment, and because he thinks that the mental is not the brain.

Thirdly, consciousness is not an experience – for similar reasons to those used to argue that it has no object. This is true despite the fact that consciousness may inevitably be accompanied by experience.

Minimal Requirements For Consciousness

What can we learn about consciousness by asking what are its minimal requirements? Consider the simplest possible conscious animal. It does not seem to need any motor or perceptual capacities in order to be conscious; all the requirements for consciousness are internal. There must however be attentive experience which generates beliefs about the environment. We do not need to ask how this could occur without perceptual systems, because the key criterion for consciousness is cognitive sensitivity to perceptual experience. This means something can be conscious if it would respond to perceptual input about the environment in the right way, were there to be any. While this looks implausible, it must be true unless we wish to deny that persons in sensory-deprivation tanks are conscious.

There is a contrast between the normal state of consciousness and that which obtains when dreaming. O’Shaughnessy diagnoses this as relating essentially to awareness of time. In particular, normal consciousness requires the capacity to perceive events across time.

See Also:

Does Nietzsche Favor Master Morality Over Slave Morality?

Nozick’s Claim That Knowledge Is Truth-tracking: A Critical Evaluation

Putnam on Functionalism: Summary

Should Nozick Call Darwin As A Witness?


Experience Time and Experienced Time

This is mostly a question for Tye. It asks whether the time it takes to have an experience is the same — and if so, is it necessarily the same — as the time it takes for that experience to be had. These might look the same at first glance, but they’re not.

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Phillips cites Tye as follows: “Tye holds that the natural explanation is that, our brains collect information a little into the future before an experience is generated, so that what we experience as the present is in reality a little in the past’. The term ‘collecting […] into the future’ is somewhat misleading because processes can only occur in the present. What Tye means is that processing takes place at times beyond which the experience is ‘time-stamped’ by the brain; alternatively, that there is a gap between the objective external time of the event causing the experience and the objective external time at which the perceiver has the experience of that event.

At some level, this must be true, since time is required for perceptual processes to occur. Photons must travel from the external object of which the experience is a perception to the retina; a vanishingly small yet non-zero amount of time. Those photons must impinge on rod and cone receptors which will require a further non-zero amount of time to produce corresponding signals. Those signals must travel to V1 for early processing; subsequent processing takes place in other contiguous but not co-located areas of the visual cortex. It seems to be common ground that all of these steps will sum to a time period of the order of several hundred milliseconds.

Phillips reproduces Tye’s diagram showing how Tye thinks this allows for an explanation of postdictive effects. In these effects, an experience of an event A is modified by a later experience of an event B, providing that event B is within the same several hundred millisecond window. The inter-experience gap must be shorter than the processing window, since otherwise the perceptual system would already have pronounced on event A and the experience of event A would no longer be available for modification by event B. This generates a question, which is also illustrated by the fact that the lines on Tye’s diagram are not parallel: they converge such that there is an experience of zero duration – one might also wonder if that is coherent – which reflects events of non-zero duration viz. the time of event A, the gap between A and B, and the time of event B. The question is: why does the processing of event B take no time or why does it take less time than the processing of event A?

Intuitively, one would expect the processing time to be roughly independent of the event type. The perceptual delay would be constant, in rough analogy with ‘live’ TV broadcasts where it is common to introduce a five second delay above and beyond the ‘processing time’ involving light reception by cameras, signal transmission to broadcast towers etc. to allow broadcast interruption in case of the occurrence of events it is not desired to broadcast. Tye’s model, on the contrary, seems to involve variations in the lag time. Are there implications for Phillips’s interpretation of the Sperling data?

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Phillips notes, in fact, that “some aspects of experience, say, contour detection [may be] subject to a smaller delay than, say, surface completion”. The Phillips variation is based, plausibly, on the idea that processing time required for a particular task may be different to the processing time required for a different task, and that the processing times will be similar on each occasion that the particular task is completed. But this is insufficient to rescue the Tye account. That requires that the processing time for a particular task be a function of its postdictive effects such that the former can permit an explanation of the latter. An argument would be required for such a covariance.

Phillips seeks to support Miller’s PPC — Principle of Presentational Concurrence — which holds that “the time interval occupied by a content which is before the mind is the very same time interval which is occupied by the act of presenting that very content before the mind”. The support is supposed to come from Extensionalism, which is the claim that “our consciousness essentially ‘extends a short distance through time’ ”.\footnote{Phillips \cite[p. 397]{phillips11}.} But \emph{everything} which exists must exist for a non-zero amount of time and so nothing specific may be learned about consciousness from the Extensionalist claim. In addition, the Extensionalist claim only suggests that the ratio (content occupation time) / (content presentation time) is non-zero whereas the PPC requires it to be exactly 1.0. Why?

See Also:

What Is “Theory Of Mind?”

Science Is Not A Religion

Merleau Ponty’s Phenomenology: What Is It And How Cogent Is It?

Does The Observation That Knowledge Ascriptions Are Context-Sensitive Provide The Basis For A Satisfactory Response To Scepticism?


[1] I. B. Phillips, “Perception and iconic memory: What sperling doesn’t show,” Mind and Language, vol. 26, no. 4, pp. 381–411, 2011.

[2] G. Sperling, “The information available in visual presentations,” Psychological Monographs, vol. 74, pp. 1–29, 1960.