Week 1 Flashcards
How many senses?
More than 5
- Vision
- Audition
- The Chemical Senses:
–> gustation
–> olfaction - the body senses
–> somatosensation (taction, proprioception)
–> equilibrioception
How does perception effect neuropsychology
- Apperceptive/associative agnosia: inability to recognise objects
- phantom limbs
- rubber hand illusion
- alien hand syndrome
How does perception effect clinical psychology?
Eating disorders (body image distortion)
Inability to recognise facial emotion in…
- psychopaths
- people with depression/autism/schizophrenia
How does perception effect forensic psychology?
Eye witness testimony
Physiological principles
transduction
hierarchical processing
selectivity
organisation
specific nerve energies
plasticity
noise
Physiological principles : transduction
- first stage of any sensory process: turning physical energy into neurons we can process
- receptors turn energy into neural signals
- impulses travel along axons to terminals which release neurotransmitters across synapses to be received by another cell
Physiological principles: hierarchical processing
- neural impulses travel “up” the system to the cortex
- relay station in the thalamus (except olfaction)
- higher cortical areas also involve lateral and feedback connections
Bottom up: flows of information from sensory receptors towards “higher” cortical areas
Top down: prior knowledge influences what is perceived
Physiological principles: selectivity
- nerve cells specialise in certain things - have trigger features, neurons will respond best to certain properties
- visual cortex - nerve responds a lot to a vertical line - i.e. it is tuned to a vertical line
Physiological principles: Organisation
- orderly progression of stimulus preferences within sensory brain regions
- cortical magnification: most important range of stimulus values is processed by larger amount of cortex
Physiological principles: Doctrine of specific nerve energies
- each sense projects to a different cortical area
- the nature of a sensation depends on which sensory fibres are stimulated, not on how fibres are stimulated
Physiological principles: Plasticity
- neural mechanisms are modifiable
- development
- recovery from brain injury
- calibrated change: you body changes over time - you’re brain adapts to learn more
Physiological principles: noise
Neural firing is stochastic (subject to influences from the stimulus but also a little bit of random variation as well)
precise firing rate determined mostly by stimulus but also by other random factors
Spontaneous activity - cells fire a little even with no stimulus
Perceptual principles
Detectability
Sensory magnitude
Discrimination
Adaptation
Perceptual principles: detectability
- the more intense the stimulus, the more likely you are able to detect it
- detection threshold: the intensity required for detecting a stimulus
- sensitivity (opposite of threshold): 1/threshold
Sensory magnitude
- more intense stimulus –> higher magnitude of sensation
- measure with magnitude estimation technique
- compressive non-linear functions (if you double the intensity, the sensation is less than double)
