Chapter 4 - Sensation and perception Flashcards
David Hume
formalised the laws of contiguity and similarity and challenged the concept of causality
- believed objective reality is something people cannot experience in a pure state
Immanuel Kant
German philosopher trained on the works and ideas of Leibniz, but interested in David Hume
- described the pure state as the noumenal world: the world around us, the world outside of our existence and experiences, experienced by the senses
phenomenal world
when the noumenal world is experienced by the human senses
- consists of the appearances of objects
- structured by human intuition (how we perceive objects in space and time) or categories (through which we filter our experiences)
Charles Bell’s law of specific nerve energy
established that each sensory nerve is capable of transmitting only one type of sensation
- if a nerve processes visual information, that same nerve cannot also process auditory information
- further developed by Johannes Müller
Johannes Müller
was convinced that all living organisms have within themselves a non-physical life force which cannot be studied (vitalism)
Hermann Helmholtz
adopted the doctrine of physiological mechanisms
- all physiological processes can be understood using physical and chemical principles
- did research on frogs to test physiological mechanisms
- found the idea of conservation of energy
conservation of energy
energy can be transmitted from one place to another, but it can never be lost
Helmholtz and reaction time studies
gave him insight to sensations
- purely mechanistic way in which we process infromation from the outside
Young-Helmholtz’s trichromatic theory
there are 3 types of receptor cells, one for each primary color of light (red, green, blue)
perceptions (Helmholtz)
the meaningful interpretations of sensations
perceptual adaptation (Helmholtz)
how we adapt to our environment, how we adjust the way we perceive the world
- he believed this was due to unconscious inference about reality: the brain automatically thinks in a logical way about the world
Eleanor Jack Gibson’s ‘visual cliff’
went against Helmholtz idea that perceptions are learned, as young subjects had depth perception without the necessary experiences according to Helmholtz
Gustav Fechner
laid foundations for psychophysics to discover a mathematical relationship between the ‘physical intensities’ and the experienced intensities
- measured the strength of the stimulus and observed sensitivity to it
Ernst Weber
discovered the ‘just noticeable difference’ (JND)
- S = k log P
- S for sensation and P for physical/objective difference
absolute threshold
the smallest intenisity of a stimulus that can be perceived at all
