Roberts, F.S. (1989). Some implications of the voluntary control of visual perception. JSPR 56, 309-310.
Reproduced with the kind permission of Peter Roberts.
List of papers by the author; archived at

Some implications of the voluntary control of visual perception

by F. Somerville Roberts

An example is given of the control of visual perception by voluntary effort, thereby indicating a possible non-cerebral origin for some percepts. Confirmation is provided by describing other sources of images. The significance of this situation is discussed in relation to neo-Cartesian dualism and hence its influence on the purely mental aspects of parapsychology. An example is given of its confirmation of Tyrrel’s theory of apparitions.

Reference has recently been made by Roberts (1988, 1989) in Letters to the Editor of the phenomenon of the voluntary control of visual perception, but its fuller implications for parapsychology are unlikely to be gathered from those brief comments. As it may have some significance in the area of neo-Cartesian dualism, on the validity of which many aspects of parapsychology depend, a brief description of this phenomenon is repeated here, in order to give the background to the following remarks.

It is possible for the images of visual perception to be controlled by voluntary effort or 'will power'. A simple illustration of this takes place when an observer is watching a radar scanner, or anemometer, or some similarly constructed device, rotating in the line of sight and at a suitable speed. By simply 'willing it' or rather, convincing himself that it will rotate in the opposite direction, he will, within a few seconds, see it doing so. He will have complete control over the direction of rotation, reversing it when he wishes to, or maintaining it indefinitely in either direction, and both directions will be indistinguishable and equally 'real' to him.

When viewing an anemometer, an observer sees it rotating in a clockwise direction, and a moment later it is anti-clockwise. What has changed within the observer to account for the new situation? Simply that he 'willed' it, (and the actual mechanics of this operation are irrelevant here). He convinced himself that the change of direction would take place, and it did. In other words, he believed the arm was rotating in the opposite direction and that was sufficient for him to see that it was doing so. This suggests that we do not necessarily see what is there, but what we believe is there, irrespective of what the retinal system or visual cortex are registering. This point was suggested by Tyrrell as the basis of his theory to account for apparitions, although he did not call on the confirmation offered by voluntary perception.

It would thus appear that normally induced visual images are not dependent on sensory stimuli alone, but can possibly be generated by a secondary agency. Confirmation of this view would appear to be forthcoming from the work done on hypnotic hallucinations. Recent work may have cast doubt on many of the earlier claims in this field, classifying them as largely make-believe and playacting. It is therefore necessary in the first place to establish one indisputable fact. If a suitably susceptible subject is instructed under hypnosis that he cannot feel pain in, for example, his foot, then in spite of the most drastic treatment, or intense existing pain, he will not have any perception of pain. This fact is confirmed by hundreds, and possibly thousands, of medical reports by eminent surgeons, obstetricians, dentists, etc., in many parts of the world, and must be accepted as verified.

There are some investigators who maintain that in the inhibition of pain in hypnosis, what actually happens is that we continue to experience the pain sensation but that the subject becomes, as a result of verbal suggestion, indifferent to these ordinarily disagreeable sensations. As it is accepted that in such a case there is prior conscious experience of pain which is subsequently inhibited by hypnosis, the argument is simply a theory as to how this inhibition is achieved, and does not affect the validity of hypnotic control of conscious experience.

There is thus little doubt that pain is a perceptual experience and that it is basically the same as touch, taste, hearing etc. Unless it can be clearly demonstrated that there is some fundamental difference in the nature and behaviour of the different forms of perceptual experience, there is every justification for claiming that their responses to hypnotic instruction will all follow the same pattern.

If, therefore, a hypnotised subject suffering from toothache is instructed that he is unable to feel the pain, and also that he is unable to see the flowers on a nearby table, he will no longer feel pain, nor will he see the flowers. If the pain inhibition component of the hallucination clearly demonstrates verbal control of perceptual activity, as the medical reports show to be the case, so, too, does the visual component. Attempts to explain the visual part of the hallucination as arising from play acting, make-believe, etc, while having to admit verbal control in the neutral part, can no longer be regarded as valid. In other words, visual perceptual images can be created and controlled by hypnotic instruction, irrespective of what the retinal system or visual cortex may be registering.

Another source of perceptual imagery is the apparition. From the anecdotal accounts in the literature, it is clear that apparitional hallucinations can be as vivid and real as sensory images or hypnotic hallucinations and can be identical in their characteristics. At the moment the unknown factor is, of course, the initiating source within the consciousness. It would thus appear there are at least four separate agencies capable of creating identical visual images: sensory stimuli (including abnormal physiological conditions), voluntary effort, hypnotic instruction and (without experimental confirmation) apparitional influence, and it is difficult to avoid the conclusion that the images from all four sources are created within the same stratum of consciousness and are comprised of the same elements. This suggests that either there are four brain areas each with its own route and mode of communication with the visual cortex and capable of creating therein the same brain configuration, or the four areas are associated parts of a single entity independent of the visual cortex, and within which the creation of perceptual images takes place. The application of the principle of Occam's Razor certainly suggests that the former hypothesis should be ruled out. Furthermore, it can be shown that it could not have come into existence through organic evolution. If a creature at some time in the past with the necessary genetic mutation for the voluntary control of perception, were being chased by a predator, and found that by simply willing it, the threatening predator apparently reversed direction and went away, then the creature would believe there was no need for evasive action on its own part. As a result he would be killed and so unable to pass on the mutation necessary for the evolution of the faculty. It would thus appear that the second hypothesis is the more tenable, and as a result. Tyrrel's theory of apparitions would now appear to rest on a firmer base than was previously considered to be the case.

In his apparitional theory, Tyrrell (1953) put forward the suggestion that there was a stratum of consciousness quite distinct from the brain, which was able to create all forms of perceptual activity from an initiating 'idea'. It would now appear that this 'idea' could arise within a source such as any of those mentioned above. He explained that whilst this area of consciousness could create images from information presented by the visual cortex, this was only a guiding factor and there was nothing to compel the consciousness to act on this information. It could reject the 'idea', in whole or in part, if a more emphatic 'idea' were presented by any other source. Consciousness would react in favour of the dominant 'idea' and the effect would be the creation of an hallucinatory percept which could be imposed, if appropriate, on a sensory background, thereby explaining the anomalous behaviour of the anemometer observations.

 In his 'Minds and Higher Dimensions' Smythies indicates that consciousness could be a 4-space dimensional entity, in which case it could be aware of the entire brain state at any one moment. In such circumstances, it would be immaterial whether the 'idea' arose in the visual cortex, the auditory area, by conscious volition or, more speculatively, by telepathy, because to a 4-dimensional consciousness they are all equally accessible and significant, and it would respond by creating the appropriate image—even if this should be an apparition! In fact, we might have here an indication of the existence of another kind of ghost—the Ghost in the Machine—which was postulated by Ryle (1949) and which, in his own words, he rejected with deliberate abusiveness.

The 'idea' hypothesis could also account for some of the anomalous aspects of sensory perception. For example, we see with two eyes, each with its own retina, and these are mapped onto the two hemispheres of the brain in such a way that the visual cortex of the left hemisphere mediates the right visual field and vice versa. That we nevertheless experience a single unbroken field of vision suggests that it is difficult to account for this phenomenal fact in purely physiological terms. Again, the brightness of a percept is dependent on the degree of illumination of the field of vision, and if this illumination is substantially reduced the retina will record this fact and the brightness of the image will follow correspondingly. However, if one eye is closed, thereby halving the total retinal illumination, the brightness of the image is not appreciably affected. In any physical reaction where the result is dependent on the stimulus applied, any change in the stimulus causes a change in the outcome, but visual perception does not appear to conform to this law of physics. There may be a physiological explanation for these and similar anomalies, but on the other hand, they are the expected predictions of Tyrrel’s 'idea' theory. In the case of binary vision, only one 'idea' is presented to the consciousness, in spite of both eyes registering the field of vision, and so only one image is created, and since it can be formed by either eye, closing one eye will not significantly change the image.

The existence of voluntary control of perception lends support to the theory that the creation of perceptual images is not necessarily dependent on a brain configuration. Unless this neo-Cartesian concept can be shown to be false, not only is Tyrrel’s theory of apparitions appreciably strengthened, but a rational basis is provided for the purely mental phenomena of parapsychology.

Ashford, Kindlestown Hill
Delgany, Co. Wicklow

- Roberts, F. S. ( 1988). JSPR, 55, 164.
- Roberts, F. S. (1989). JSPR, 55, 309.
- Ryle, G. (1949). The Concept of Mind.London, Hutchinson
- Smythies, J. R. (1988). JSPR, 55, 150.
- Tyrrell, G. N. M. (1953). Apparitions, London, SPR/Duckworth.