6 The relations among mental phenomena
There is no escaping the fact that want of sympathy condemns us to a corresponding stupidity. Mephistopheles thrown upon real life, and obliged to manage his own plots, would inevitably make blunders.
(George Eliot, Adam Bede)
We have seen that it seems natural to say that while it is possible for machines and angels to have intellects superior to ours, it is also natural to say that they will be subject, to far less extent, to that range of sensuous, perceptual and emotional experiences that infuses human mental life – and even perhaps to no extent at all. This raises the question of what the relation is among the various mental phenomena. Consider reason and emotion, for example. It is common to think that thought or reason is a relatively autonomous feature of the mental, in the sense that it can operate successfully in a creature without emotion. Indeed, the idea of a purely rational creature unadulterated by any emotion is one often contemplated by philosophers and lay people alike as not only a possibility but the kind of creature we should positively strive to become. But just how independent of emotion is rationality really? Recent research in neuroscience has begun to cast some doubt on the idea that rationality, at least our rationality, is an autonomous domain that can function independently of emotion. It seems that an absence or distortion of normal emotional functioning can lead to breakdowns in rationality. People who suffer certain kinds of damage to those parts of the brain thought to control and regulate emotional responses often have serious problems making decisions, forming plans and generally organising their life in a safe and successful way. Some neuroscientists think that emotional states, which appear to be subserved by neural mechanisms in certain areas of the brain, bias or ‘colour’ certain of our memories, experiences and thoughts by ‘marking’ them with degrees of urgency and calm, which have the effect of driving certain thoughts into our attention and pushing others away. Emotions may be the wheels of thought, allowing us to concentrate on important things without being swamped with too much ultimately irrelevant information.
Much of the evidence for the interconnection between the various aspects of our mental life comes from the investigation of people with brain damage and mental illnesses. Among the more extreme types of mental illness is the Capgras delusion, and reflection upon it suggests another possible link between different types of mental phenomena, this time between emotion and perception. Capgras patients believe that a close relative – usually a spouse or parent – has been replaced by an impostor who looks exactly like the replaced person. Depending on the background knowledge of the patients, the impostor may be thought by them to be a robot or a clone. The delusion is relatively circumscribed in the sense that the subjects do not integrate the delusional belief with the rest of their knowledge about how the world works. For example, they do not initiate searches for the people who they think have been replaced and do not contact the police; indeed, they seem relatively uninterested in the location or fate of their spouses or parents. The patients’ reaction to the ‘impostor’ can be friendly but is often antagonistic. That the delusional belief is sincerely held, and that the subjects are not ‘faking it’, is borne out by the fact that the delusion is sometimes accompanied by violent behaviour against the ‘impostor’ who can appear malevolent or evil to the patient. One man with the Capgras delusion decapitated his stepfather, whom he believed to be a robot, in order to find the batteries and microchips he thought would be in his head. Another Capgras patient stabbed and shot both her parents.
One of the most promising lines of explanation for this sad and disturbing delusion is that the patients in question form the delusional belief in order to explain a very strange and anomalous perceptual experience they undergo when they see the relatives in question. The idea is that Capgras patients have lost the increased emotional or affective responses that normally accompany the perception of familiar faces but have retained the separate capacity to recognise them. The ‘impostor hypothesis’ is an attempt to explain this very peculiar perceptual experience of seeing a person exactly like your spouse, say, but oddly feeling no affection or emotional attachment towards him or her. (This is similar to what seems to be happening to people in the early eerie part of the ’50s science-fiction thriller Invasion of the Body Snatchers, in which townspeople begin to think that some of their closest relations have been replaced by duplicates or clones.) This is supported to a certain extent by the fact that when some Capgras patients speak to the person in question on the phone they do not think that they are speaking to an impostor but to the real person, the very person who, when seen by them, they think is an impostor. In these cases, it is only their visual experience that is drained of emotional significance; their auditory experience remains suffused with emotional import.
In another type of bizarre case, the Cotard delusion, patients sometimes think that they are dead. This seems to be another type of reaction to undergoing strange perceptual experiences that are drained of emotional significance owing to an even more pervasive flattening of affective response to perceptual stimuli. These absent or reduced affective or emotional responses have a significant impact on perceptual experiences themselves and, ultimately, on thoughts and judgements. The upshot is that the emotions may be intimately involved in the proper functioning of perception.
Yet another baffling type of psychopathology is described by Sacks (1986) in his book The Man Who Mistook His Wife for a Hat and suggests a possible link between imagination and perception. The eponymous patient, known to us as ‘Dr P’, has severely, but very oddly, impaired perceptual abilities. Though he has no deterioration in any of his other mental abilities (he is a very talented musician), he can no longer recognise his students or identify members of his family from photographs. He cannot recognise the sexes of people on the television or their emotional expressions. He regularly confuses animate objects, such as his wife's head, with inanimate ones, such as his hat (he tries to ‘put on’ his wife's head thinking it is his hat). He can no longer recognise everyday objects, such as flowers, shoes and gloves. When asked by Sacks to identify a glove Dr P responds with: ‘a continuous surface infolded on itself [which] appears to have five outpouchings’. It seems as if Sacks's musician has lost the capacity to understand or interpret or categorise his own visual experiences even though he can describe in strikingly intelligent detail, using sophisticated geometrical concepts, what they are like. But exactly which aspect of his mentality has become impaired or is ‘missing’? It appears to be neither his rationality nor his visual perception. Could some of his imaginative abilities have somehow become debilitated? Although he can see a pair of gloves in all its geometrical detail he can no longer see them as gloves, the way we can see them as gloves or the way that, as Shakespeare's Antony puts it,
Sometime we see a cloud that's dragonish;
A vapour sometime like a bear or lion,
A towered citadel, a pendent rock,
A forked mountain or blue promontory
With trees upon't that nod unto the world
And mock our eyes with air.
For Sacks's poor Dr P, however, the situation is lamentably like that in which Antony thinks he finds himself:
That which is now a horse, even with a thought
The rack dislimns, and makes it indistinct,
As water is in water.
(Antony and Cleopatra, Act 4, Scene 14)
It is even worse than this, of course, for Dr P; for him the identities of even ordinary objects have become ‘dislimned’. Ludwig Wittgenstein (1889–1951) notes that
We do not see facial contortions and make inferences from them (like a doctor framing a diagnosis) to joy, grief, boredom. We describe a face immediately as sad, radiant, bored, even when we are unable to give any other description of the features. – Grief, one would like to say, is personified in the face.
(Wittgenstein 1967, §225, 41)
It appears that Dr P has lost the capacity for instant recognition and is confined to making inferences from facial contortions to emotions and from the shapes of objects to what kind of objects they are. If certain imaginative abilities are required for seeing-as, and seeing-as required for certain kinds of perceptual experiences – such as visually experiencing emotion personified in a face – then the prospects for building a mechanical device, such as a robot, with perceptual abilities approaching our own may depend on the device in question possessing some kind of imaginative capacity. Again, we are confronted with the possibility of a strong link between what may appear to be autonomous mental phenomena: imagination and perception.
The link between visual experience and perception is no more straightforward, however, than that between imagination and perception. While Dr P may not be able to see certain shapes as kinds of things (as gloves, say) he does at least have visual experiences of shapes and objects; that is, he is aware or conscious of shapes and colours. But there are well-documented cases of people who are, in some sense, able to perceive things that they claim to have utterly no awareness of. This phenomenon, called ‘blind sight’, occurs in people who have suffered damage to the visual cortex in their brain. They have a blind spot or scotoma, an area of the visual field that is a phenomenological blank. But interestingly, although these people deny they are conscious or aware of anything at all within the region of their scotoma, they can guess what kinds of simply shaped objects or patterns are held before them in the blind spot region when urged to do so and they can do this with an accuracy better than chance. They seem still to be receiving some kind of ‘information’ or stimulation through their eyes from the objects but are not conscious of it. It seems in these cases that there is still some unconscious processing going on which is divorced from the usually accompanying visual experience.