Evolutionary Psych – Chapter 5: Consciousness
The term “consciousness” is used in several senses. The main ways the textbook discusses are:
1.) Consciousness as wakefulness (vs. being asleep/unconscious)
2.) Consciousness as voluntary action (ex. Putting food in mouth is a conscious action; digestion is not)
3.) Consciousness as awareness
Scientists are able to study consciousness even though they do not have a complete definition of it.
1.) Consciousness as Wakefulness
Why do we sleep?
Sleep functions to keep animals quiet and safe (out of harm’s way) during the time of day for which they are not adapted.
o Under controlled light conditions, participants slept for 3 hours longer when light pattern was 14 hours darkness, 10
hours light compared to 8 hours darkness, 16 hours light.
Daniel Dennett (1995) – “Why are we ever awake?”
o Being awake is risky – high energy consumption. Sleep was important to the survival of hunter-gatherers because they
could not waste energy.
o When food is scarce, many animals hibernate, go into metabolic depression, or estivate to save energy
Percent of time spent sleeping varies widely among animals
o Larger animals and predators sleep more than smaller ones and prey (it is safer for predators to sleep than prey)
o Woody Allen said, “the lion and the lamb shall lie down together, but the lamb will not be very tired”
2.) Consciousness as Voluntary Action
We assume out thought processes are readily available to consciousness
Function of consciousness is to allow ourselves to focus on novel problems and have routine ones dealt with automatically (ex.
We consciously talk while the vestibular maintains balance unconsciously allowing us to also walk)
Example: Eye movements are the most common voluntary human behaviour, however the actions we perform to move our eyes
to look in different directions are unconscious (saccadic eye movements)
There are also unconscious cognitive processes
o How do you being a fact to mind?
o How do you understand/perceive speech?
o How do you judge depth, distance, see colour?
o We use the cognitive unconscious.
Cognitive impenetrability – processes that are inaccessible to consciousness and are unaffected by it (such as depth and size
perception – Müller-Lyer Illusion)
Behaviour should not be equated with consciousness
Some behaviours are conscious during learning, but become unconscious once automatic
Controlled processes require our conscious attention (performed slow and effortfully and more easily distracted)