Introduction, philosophy, psychology and neuroscience of perception Flashcards
Define sensation
awareness of a physical stimulus through the senses
define perception
the ability to apprehend, or become aware of something through the senses
Difference between sensation and perception?
received sensory data VS interpreting sensory data
Psychological relationship of sensation and perception
Perception brings our knowledge of the world to organise the raw data of sensation
What are the neural requirements for sensation and perception?
- sensory receptors -> transduce signals
- axonal projections to CNS -> stimulation
- central pathways through CNS
- leading to specific sensory area of cerebral cortex (primary visual cortex receives input)
- on to ‘higher’ association areas of cortex
Perception via the senses?
- Direct perception (naive realism)
- Indirect realism: we cannot perceive objects directly
- We experience sensations perceptions, which we assume are reliably due to the real world- Physics (sound, light, mechanical forces)
- sensory detectors
- CNS processing
- Perceiving: constructing a mental representation of it
Representational model of the mind
- Outer world - physics: mass, energy, molecules
- Inner world - mental states: sights, sounds, etc
What about the problem of scepticism?
- Possibility of radical skepticism?
- Trusting our sense data? Dreaming?
The mind-body problem
- Dualism: there is mind-stuff and there is physical stuff and they are fundamentally different kinds
- Materialism: also physicalism, there is no reality but physical reality
Problem of perception?
- Reliability of perception = philosophical problems
- does all knowledge come from sensory experience?
Origins of knowledge
Empiricism vs Nativism
Empiricism (blank state):
- all knowledge comes from sensory experience, ordered by learning associations between experiences
- implies a passive view of perception
Nativism:
- the way we organise experience depends on innate knowledge
- the perceiver is actively involved in interpreting the sensory input
What does perception depend on?
- Implicit knowledge
- assumption that the world is 3D
- Helmholtz (1867): perception as unconscious inference
What is perceptual processing?
There are 2 types; bottom-up and top-down