Part Of: Consciousness sequence
Content Summary: 1600 words, 16 min read
Inspiration: Baars (1998) A Cognitive Theory of Consciousness.
Automatization in Tasks
Almost everything we do, we do better unconsciously than consciously. In first learning a new skill we fumble, feel uncertain, and are conscious of many details of action. Once the task is learned, we lose consciousness of the details, forget the painful encounter with uncertainty, and sincerely wonder why beginners seem so slow and awkward.
In dual task paradigms, subjects are asked to perform two tasks simultaneously. Performance is often poor, because of the limited capacity of consciousness. But when a subject extensively practices one of these tasks, the task will stop interfering with others, and performance improves.
Consider reading, the act of translating visual letters into conceptual meaning. Reading proceeds automatically. If you see the word “pink”, it is nearly impossible to avoid subvocalizing and imagining the color (inner speech and semantic recall). You are not aware of identifying individual letters, or searching your memory for the requisite sounds and meanings – they just occur.
Driving a car is yet another example of a skill that becomes automatic:
When we first learn to drive a car, we are very conscious of the steering wheel, the transmission lever, the foot pedals, and so on. But once having learned to drive, we minimize consciousness of these things and become mainly concerned with the road, with turns in the road, traffic to cope with, and pedestrians to evade. The mechanics of driving become part of the unconscious frames within which we experience the road.
But even the road can be learned to the point of minimal conscious involvement if it is predictable enough: then we devote most of our consciousness to thinking of different destinations, of long-term goals, and so forth. The road has itself now become “framed”. The whole process is much like Alice moving through the Looking Glass, entering a new reality, and forgetting for the time being that it is not the only reality. Things that were previously conscious become presupposed in the new reality. In fact, tools and subgoals in general become framed as they become predictable and automatic.
Why, when the act of driving becomes automatic, do we become conscious of the road? Presumably the road is much more informative within our purposes than driving has become. Dodging another car, turning a blind corer, braking for a pedestrian – these are much less predictable than the handling of the steering wheel.
The process of automatizing a skill is called habituation. Habituation involves an increase in performance and a decrease in demand for cognitive resources. But it also involves:
- loss of self-monitoring: an unpracticed beginner is aware of their own performance, but an expert practitioner can be deceived into believing her performance was much less than its actual value.
- loss of long-term working memory. Consider, in typing, which finger is used to type the letter c? Most people have to consult their fingers to find out the answer
Suppose someone is given a shape from among the following set, and asked to memorize it. They then receive pairs of other images, and select which one is more similar.
Pani (1982) found that, as subjects practiced the task, the original image faded from consciousness even as the responses became faster and more accurate.
Automatization in Perception
The Pani experiment suggests that not merely actions that move to autopilot. Perception can fade from consciousness as well.
Consider the pressure of the chair you are sitting in. Before I mentioned it, that tactile sensation had likely faded into the background. In contrast, the visual experience of reading these words was very much at the center of your conscious experience.
What is the difference between the tactile quality of the chair and the visual experience of these words? Redundancy! The chair feels very similar one moment to the next, whereas each new word has a subtly different experience.
These redundancy effects are pervasive. Consider the experience of moving to an area with a distinctive smell. For the first few days, the smell is at the forefront of your conscious experience; but over time, this redundant sensation fades to the background.
We have seen redundant touch and smell fade from consciousness. Why don’t we become blind to redundant visual information?
Unlike touch and smell, our fovea constantly move across the visual field in an involuntary movements called saccades. This might be one way that the visual system combats redundancy.
If you mount a tiny projector on a contact lens firmly attached to the eye, you can ensure that the visual image is invariant to eye movements. Pritchard et al (1960) found that in such conditions, the visual image fades in a few seconds. Similarly, when people look at a bright but featureless field (the Ganzfeld), they experience “blank outs” – periods when visual perception seems to fade altogether. (Natsoulas, 1982). When vision is not protected by saccades, it behaves just like the other senses.
Becoming blind to redundant information is not limited to perception. Semantic satiation occurs when a person repeats the same word over and over again, until the word starts to feel foreign and arbitrary. Try this for yourself, say “gum” to yourself 50 times and see what happens.
There is a school of thought that interprets these redundancy effects as anatomical fatigue (perhaps processing the same image dozens of times exhausts neurotransmitters in the relevant microcircuits). But these interpretations are confounded by our ability to surprised by the lack of a stimulus, which implies that the redundancy is encoded in terms of information rather than energy.
It is also worth noting that redundant perceptions do not fade into the background if they are highly relevant to the organism’s health and goals. Chronic pain and hunger fall under this rubric. These are, however, exceptions to the rule.
Errors and Curiosity
When we experience difficulty performing automatized tasks, consciousness access returns.
- In reading, lexical access becomes automatic. But simply turning a book upside down will interfere with our reading proficiency, and the perceptual details of “stitching letters to form words” comes back to us.
- In visual matching, our ability to describe the original target image disappears as we become proficient. But by simply increasing task complexity, our ability to describe the target image returns.
- In driving, if we move to a new city, our routing autopilot procedures evaporate, and we are more conscious of navigational decisions. If we buy a new car with different operating characteristics (a more sensitive brake pedal, and less sensitive steering control), the mechanical details of driving flood back into our consciousness.
It seems that consciousness is used to debug automatic processes that run into difficulties.
We often tire of practicing tasks that we have mastered. We often tire of receiving sense data we can fully anticipate. In the case where our brain has fully habituated to some phenomena (and indeed, often before that point is reached), curiosity moves our attention towards other domains. This impulse towards novelty is one way our brain builds a diverse coalition of mental modules capable of responding to an intrinsically complicated world.
Towards A Theory of Conscious Learning
From the global workspace perspective, we expect consciousness to be involved in learning novel events. Such learning requires unpredictable communication patterns between modules; a feat only possible by way of widespread broadcasting.
Consider the radical simplicity of the act of learning itself. To learn anything new, we merely pay attention to it. By merely allowing ourselves to interact consciously with a new language – even without a learning plan, nor knowledge of its syntactic structure – we nevertheless “magically” acquire the ability to comprehend and speak.
Today we explored the relationship between learning, and the habituation of awareness. Baars says it best,
Habituation is not an accidental by-product of learning. Rather, it is something essential, connected at the very core to the acquisition of new information. And since learning and adaptation are perhaps the most basic functions of the nervous system, the connection between consciousness, habituation, and learning is fundamental indeed.
Factoring in our observations about error and curiosity, it seems as though learning can be modeled as a push-pull system. Learning promotes habituation, error promotes deautomization, and curiosity redirects the brain to different activities if the current one has been mastered.
The learning-surprise versus curiosity systems bears a striking resemblance to the reinforcement learning dichotomy of exploitation versus exploration.
Towards The Future
I noted in Function of the Basal Ganglia that habituation has been associated with control shifting from the associative to the sensorimotor loop in the basal ganglia. This is hard to reconcile with the neurological basis of consciousness in the corticothalamic system. A more systematic account of these biological interactions is required.
Consciousness has been linked to many other functions besides learning and habituation. It is most natural to interpret polyfunctional biological systems like this to have accreted function across evolutionary time. Untangling the phylogenetic ordering of these subfunctions (peeling the onion) is an important task that will require input from comparative anatomy.
The consciousness organ is not the only system to exhibit redundancy effects. Habituation to repeated input is a universal property of neural tissue. Even a single neuron will respond to electrical stimulation at a given frequency only for a while; after that, it will cease responding to the original frequency, but continue to respond to other frequencies. (Kaidel et al (1960). The relationship between the specific corticothalamic system and these microproperties of neurons is also an open research area.
Until next time.
- Baars (1998), A Cognitive Theory of Consciousness, especially sections 1.2.4, 1.3.3, 1.4.1, 1.4.4, and 3
- Pani (1982). A functionalist approach to mental imagery.
- Pritchard et al (1960). Visual perception approached by the method of stabilized images.
- Kaidel et al (1960). Sensory Communication (pp 319-338).
- Natsoulas (1982). Dimensions of perceptual awareness.