Sensory and Perception Flashcards
Neurons
- recieve and transmit info
- electromagnetic activity
How are stimuli from environment represented via neuronal activity in the nervous system?
- vision-occipital lobe
- Hubel and Wiesel
Specificity Coding
- a person’s face is represented by one neuron, which fires to that face ONLY
Distributed Coding
- a person’s face is represented by a group of neurons
Frontal Lobe
- higher level functioning
- planning
- speech
Temporal
- language comprehension
- memory recognition
- object recognition
Parietal
- attention
- spatial processing
Stripe-rearing kittens experiment
- born and put into 2 different groups (experimental vs control)
- experimental condition is room with vertical stripes only
- control is normal environment
- in test phase, control kittens react to all angled stripes
- experimental react on mostly only vertical stripes
- EXPERIENCE IS CRITICAL TO DEVELOPMENT
Experience-dependence plasticity in humans
- fusiform face area (temporal)
- Ps shown greebles and were ttrained in greeble recognition
- then performed name verification task while activity in FFA was measured and compared before and after training
- before= more activation for faces
- after= similar activation for both
- YES we can alter the response of neurons in FFA
Pupil
controls amount of light that enters our eyes
Name some primary receptor cells
- ganglion cells, bipolar cells, rods, cones
Rods
- responsible for peripheral vision
- 130 million
- black and white vision
- outside of fovea
- sesitive to all wavelengths
Cones
- foveal vision
- 7 million
- in center of retina
- color vision
- visual acuity
Bipolar cells
- relay stations
- communicate message from cones and rods to ganglion cells
Ganglion cells
- transmit info from bipolar cells to rest of brain
- via optic nerve
- 800,000 in each eye
Lateral Geniculate Nucleus
- object recognition
Superior Colliculous
- locating objects in space
Where pathway
PARIETAL
What pathway
- TEMPORAL
Why does the brain recieve a partially “summarized” record of the original stimulus
- light travels through the vitreous humour and becomes scattered
- only a small portion of primary receptors have their own private “pipeline” to the brain
- each eye has a lind spot (no rods or cones)
Template Matching Theory
- a visual stimulus is compared to specific templates in memory
- identiy is determined by which template has the most overlap
What’s wrong with the template matching theory?
- how can we recognize things with so much variability?
- realistically we would need to learn and store a huge number of templates in memory
- this would be very time consuming and impractical!
Template Matching with Machines
- UPS created the first machine to read handwritten addresses
- it reject 85% of the envelopes
Feature Analysis Theories
- takes into account specific combos of basic features
- pandemonium
- recognition by components
Pandemonium
- mental demon shouts up towards higher stages
- image demon
- feature demon
- cognitive demon
- decision demon
- shouts=mental activity/recognition
Image demon
- detects a neural signal from sensory cells up 1 layer to feature demons
feature demons
- 28 demons
- each compares itself to info from the stage beneath
- if it matches it will shout because its present in the stimulus
Cognitive demons
- shout the ludest and hears the most shouting from feature demons
decision demon
- identifies the pattern by hearing which cognitive demon shouts the loudest
Recognition by components theory
- simple combos of basic features
- 3d shapes = geons
- paired visual stimuli with geons
- expect failure when geons are removed than when segments of geons are removed
- pattern of error depends on exposure time
- WEAKNESS- do not take into account the effect of context on pattern recognition