* Noumenal World
* Things as they are
* We cannot experience this directly
* Phenomenal World
* Things as they are experience/perceived.
* Mental representations of the noumenal world
1. Objects in the world
2. Sensations (secondary qualities, simple ideas)
3. Structuring by the mind
4. Perception, and Knowledge of universals/abstracts
* Kantian problem of Space Perception:
Lotze’s Theory of Space Perception
* Local sign: sensory address or location of stimulation on the body (tactile/touch sensation) * Movement (active touch) produces change in local sign
* Idea of spatial location is thus derived
* Empirical View, with a rationalist concept:
Haptic Theory of Space Perception
Helmholtz’s Theory of Perception
* Fusion of Kant and Berkeley/Lotze’s ideas
* Structure must be imposed on the meaningless sensations * Sensations are “raw elements” of conscious experience * Prior perceptual experience provides the structure
* Helmholtz = strict empiricist
* Unconscious Inference
* Meaning of the current set of sensations is inferred based on prior experience * The linear image of the railroad track = we have a 3d perception of the depth * You may have 2d or 3d interpretation of the world
* Past experience gives you this information says Helmholtz
1. Railroad tracks to be perceived
2. Meaningless sensations = ambiguous uninterpreted retinal image 3. A) Recall prior experience with this “scene”
B) “Figure out” the current scene – unconsciously
4. Obtain a conscious perception of what you are looking at Example – Muller-Lyer Illusion
Evidence for the role of experience
* Rare cases of individual born with visual defect, and later corrected… * Kittens raised in controlled visual environments
* Kittens raised in a drum, inside black and white vertical stripes and head fixed so it couldn’t turn. When let out, kittens weren’t even able to register horizontal lines. * Prism adaptation and negative aftereffect
* Prisms bend light. Person wearing prism goggles, image will shift and they will reach for the image and not get it. Eventually they will recalibrate their movements so that they can reach the object even with the displacement image. Now take off the prism glasses, can see normally again, but their movements still shift when they reach out for the object. Now they have to recalibrate their eyes and body back to normal. * Illusions
* Esp. Mueller-Lyer
* How does learning occur?
* Problem of infinite regress.
* Problem of Constancy
* Example: Shape Constancy – a door that is closed, slightly ajar, and halfway open. The door looks different (not always a rectangle). Despite this, we always constantly see it as a rectangle, no matter where we stand.
* French sensationalism – study of sensory anatomy
* Study of how the eye works, how the ear works
* Muller’s Doctrine of Specific Nerve Energies
* Nerves impose a structure on sensations
* Biological version of Kant’s idea
* We are directly aware only of the activity of our nerves (similar to Descartes theory of brain in a vat) * Each nerve has a specific energy; can only create a specific kind of sensation
Themes in Neuroscience
* Localization of function
* Easy to identify various parts of the nervous system
* What is function of each part?
* Can mental functions be localized to the parts?
* Franz Gall and Phrenology
* Higher mental function localized to the cortex
* More cortex = more (better) function
* We now know that brain size can not be used to compare the intelligence between two humans * Specific...