Sensation and perception.
Philosophy of perception
-Plato’s allegory of the cave: our senses = prisoners and the shadow. We are prisoners of our
senses, yet that’s all we have to shape our sense of reality.
: Perception and senses are the products of evolution, it encourage survival,
senses evolved to match the environment, hence we don’t need to hear like bat, bee, mice… etc.
-Heraclitus: everything is constantly changing. “You can never step into the same river twice”. No
two experiences can ever be identical. Perception depends on the environment and the
Perceptual systems are acutely sensitive to change.
Adaptation: senses adapt to constant stimulation. Steady/predictable conditions are less
salient than changing ones in the environment.
-Democritus: sensation are atoms leaving and making contact with our sense organs. Primary
senses are texture and weight, because they are direct contact. Secondary: atoms interacting
from object to observer, such as sight, sound… etc. This involves sensory transduction.
sensory transducer: any substance/structure that change energy from one form to another.
It transform information from the environment to neural signal.
Perception is the interpretation of these signals. Likely depends more on experience than
Nativism & Empiricism
Nativism: (Plato)—true sense is from the mind and soul. Mental abilities must be innate.
Dualism (Descartes): immaterial mind is the source of true ideas, can’t trust the senses.
*Problem: how can immaterial mind control the body?
Monism: 1 substance made up the whole universe.
Materialism vs mentalism (100% mind/soul).
Empiricism: (Hobbes): completely matter, you must relies on experience.
-Locke: Tabula rosa. Experience begin with stimulation of senses, conveyed to the mind.
Complex thoughts could be constructed from experience with a collection of sensations.
-Molyneux: restore sight in blind, some still can’t see normally. Thought kids do recover some
degree of vision.
-Berkeley: we rely on several visual cues to perceive distance, depth. Experience with the world is
most important, all our knowledge are from experience, although perception is limited.
-Hume: realibility—consistency of measurement. Validity—relationship of the measurement to
what is being measured. Perception is highly reliable, illusions are reliable but not valid. Dawn of