Arxiu del dijous, 24/01/2019

Not three but four laws

dijous, 24/01/2019

 Vilayanur S. Ramachandran and William Hirstein proposed three laws of qualia (with a fourth later added), which are “functional criteria that need to be fulfilled in order for certain neural events to be associated with qualia” by philosophers of the mind:
  1. Qualia are irrevocable and indubitable. You don’t say ‘maybe it is red but I can visualize it as green if I want to’. An explicit neural representation of red is created that invariably and automatically ‘reports’ this to higher brain centres.
  2. Once the representation is created, what can be done with it is open-ended. You have the luxury of choice, e.g., if you have the percept of an apple you can use it to tempt Adam, to keep the doctor away, bake a pie, or just to eat. Even though the representation at the input level is immutable and automatic, the output is potentially infinite. This isn’t true for, say, a spinal reflex arc where the output is also inevitable and automatic. Indeed, a paraplegic can even have an erection and ejaculate without an orgasm.
  3. Short-term memory. The input invariably creates a representation that persists in short-term memory—long enough to allow time for choice of output. Without this component, again, you get just a reflex arc.
  4. Attention. Qualia and attention are closely linked. You need attention to fulfill criterion number two; to choose. A study of circuits involved in attention, therefore, will shed much light on the riddle of qualia.

They proposed that the phenomenal nature of qualia could be communicated (as in “oh that is what salt tastes like”) if brains could be appropriately connected with a “cable of neurons”. If this turned out to be possible this would scientifically prove or objectively demonstrate the existence and the nature of qualia.


 

Three Laws of Qualia

dijous, 24/01/2019

V.S. RAMACHANDRAN & W. HIRSTEIN

What Neurology Tells Us about the Biological
Functions of Consciousness, Qualia and the Self

Neurological syndromes in which consciousness seems to malfunction, such as temporal lobe epilepsy, visual scotomas, Charles Bonnet syndrome, and synesthesia offer valuable clues about the normal functions of consciousness and ‘qualia’. An investigation into these syndromes reveals, we argue, that qualia are different from other brain states in that they possess three functional characteristics, which we state in the form of ‘three laws of qualia’ based on a loose analogy with Newton’s three laws of classical mechanics.

First, they are irrevocable: I cannot simply decide to start seeing the sunset as green, or feel pain as if it were an itch.
Second, qualia do not always produce the same behaviour: given a set of qualia, we can choose from a potentially infinite set of possible behaviours to execute.
Third, qualia endure in short-term memory, as opposed to non-conscious brain states involved in the on-line guidance of behaviour in real time.

We suggest that qualia have evolved these and other attributes (e.g. they are ‘filled in’) because of their role in facilitating non-automatic, decision-based action. We also suggest that the apparent epistemic barrier to knowing what qualia another person is experiencing can be overcome simply by using a ‘bridge’ of neurons; and we offer a hypothesis about the relation between qualia and one’s sense of self.

 

Nothing is more chastening to human vanity than the realization that the richness of our mental life — all our thoughts, feelings, emotions, even what we regard as our intimate self — arises exclusively from the activity of little wisps of protoplasm in the brain. The distinction between mind and body, illusion and reality, substance and spirit has been a major preoccupation of both eastern and western thought for millenia (Aristotle, 1961; Descartes, 1986; Fodor, 1975; Dennett, 1978; Searle, 1980). And although these distinctions have generated an endless number of debates among philosophers, little of lasting value seems to have emerged. As Sutherland (1989) has said, ‘Consciousness is a subject on which much has been written but little is known.’

Our primary goal in this paper is to forge a fresh approach to the problem, by treating it not as a philosophical, logical, or conceptual issue, but rather as an empirical problem. Our focus is on showing the form a scientific theory of consciousness might take, something which is independent of the truth of all of the more detailed claims and suggestions we will make. Our essay will consist of two sections. In part one, which philosophers can profitably skip, we describe some thought experiments to illustrate the problem of qualia, since in our experience, most neuroscientists and even most psychologists dispute the very existence of the problem. In part two, we offer numerous examples from neurology and perceptual psychology that, together with a new theoretical framework we offer, will help eventually solve the problem of consciousness. Our theory should be seen as complementing rather than replacing a host of other recent biological approaches to the problem such as those of Crick and Koch (1992), Pat Churchland (1986), Baars (1988), Edelman (1989), Llinás (Llinás & Paré, 1991), Plum (Plum & Posner, 1980), Bogen (1995a,b), Gazzaniga (1993), Humphrey (1993), Damasio (1994) and Kinsbourne (1995).

Much of our discussion will focus on the notion of qualia. It is our contention, however, that the problem of the self and the problem of qualia are really just two sides of the same coin. In part, our argument is that the self is indeed something that arises from brain activity of a certain kind and in certain brain areas, and that this activity is also closely tied to functions related to qualia. In contrast to the idea that qualia are private, subjective, and unsharable properties belonging exclusively to a private self, we suggest two thought experiments to show that there is no insurmountable barrier to sharing them. We then explore various issues involved in how qualia are generated and managed by neural systems, and by examining pathological and experimental cases that clarify these functions, we propose at the same time to clarify the nature of the self. We conclude that the self, or the thing that leads to the illusion of a unitary, enduring self, is neither a separable subject of consciousness nor a homunculus, but it can be mapped anatomically to limbic and other associated structures which ‘drive’ frontal executive processes. This view contrasts sharply with the widely held view that consciousness is based on the frontal processes themselves.

 


Journal of Consciousness Studies, 4, No. 5-6, 1997