Study Notes Flashcards
Clear protective layer on front of eye
Cornea
Coloured part of the eye, opens and closes to let in more or less light
Iris
Opening created by iris through which light passes
Pupil
Changes shape to focus on objects at different distances
Lens
Inner layer on back of eye that contains “light-sensitive” rods and cones
Retina
Bundle of axons running from retina to visual (occipital cortex)
Optic nerve
Spot on the retina where optic nerve exits eye, there are no receptors there
Blind Spot
Centre of the retina where “activity” (ability to see fine detail) is greatest
Fovea
Rods (5)
- Concentrated in periphery
- Allows us to see in dim light
- Cannot see fine spatial detail
- Cannot see different colours
- The axons of many rods synapse onto one ganglion cell
Cones (5)
- Concentrated in centre of eye (fovea)
- Allows us to see bright light
- Allows us to see fine spatial detail
- Allows us to see different colours
- In the fovea, one cone often synapses onto only a single ganglion cell
Shortest wavelength humans can perceive is?
Violet
Longest wavelength humans can perceive is?
Red
Mixing of pigments is called
Subtractive colour mixing (absorb some wavelengths, e.g. reflect red = appears red)
Mixing of lights is called
Additive colour mixing
Trichromatic theory
Perception of colour is determined by the ratio of activity between the 3 cone receptors
Opponent-Process Theory
Colour perception is mediated by neurons that can be either excited or inhibited, depending on concentration of light
Dual-process theory
Mix of both trichromatic and opponent-process theories
Feature-Integration theory
- Parallel search
- No attention required = pre-attentive (e.g. easy when looking for one feature - blue circle amongst red circles)
- No load effect
Conjunction Search
- Serial search
- Find red circle amongst blue and red squares and blue circles
Gesalts Principles
- “The whole is different from the sum of its parts”
- Figure-ground relationship
Bottom-up processing
- Stimulus driven
Top-down processing
- Knowledge driven
- Context effects
“Where and How” pathway
- Occipital and parietal lobes
- Vision of action
- Patient RV: Optic ataxia: An inability to coordinate voluntary muscular movements, without impairment of muscles or senses
“What” pathway
- Temporal lobe
- Visual for perception
- Patient DF : Visual FORM agnosia = Can’t make out shapes, can’t copy but can draw object from memory
Depth perception
- Created by light and shape
Memory model order
Sensory input –> [Sensory Memory]–> Attention–> [Working (short-term) memory]Encoding/Retrieval–>[Long-term memory]
Maintenance rehearsal = circles working/short term memory
Sensory Memory (Function, capacity, duration, type of code, forgetting)
F: Take in info until is can be processed C: Large amounts of info D: Brief T.o.C: Raw copy F: Results of decay
Working (short-term) memory (Function, capacity, duration, type of code, forgetting)
F: Conscious thought, where perceiving, comparing, feeling and reasoning take place C: Quite small D: Stays while processed (rehearsed) T.o.C: Acoustic-articulatory code F: Mostly interference but also decay
Long-term memory (Function, capacity, duration, type of code, forgetting)
F: Store info relatively permanently C: Limitless D: Relatively permanent T.o.C: Semantic (or by learning) F: Not forgotten, just lose access
Attention
If we attend information in sensory store it moves to working memory
Rehearsal
Maintenance vs elaborate rehearsal
Encoding
Controls movement of into from working memory to long-term memory
Retrieval
Access info from long-term memory and place in working memory
Iconic memory
Existence of brief visual sensory memory
Types of memory
- Explicit memory (Declarative, conscious)
- ——- Episodic (ones own experience) & Semantic (general knowledge)
- Implicit memory (non declarative, unconscious)
- ——- Classical conditioning effects (conditioned emotional reactions) & Procedural (Motor skills, habits) & Priming (Implicit activation of concepts in LTM)
Spreading activation model
Activation of any one concept initiates a read of activity to nearby concepts - priming those concepts so they become temporarily more retrievable than before
H.M
- Unable to form any new semantic or episodic memories
- Parts of temporal lobes, amygdala and hippocampus from both sides were removed
Sources of variability in Behaviour Repertoire
- Biological/physiological factors
- Developmental processes
- Experience
2 types of behaviour
Respondent & operant
Respondent behaviour (4)
- Involuntary
- Reflexes
- Seems to be pulled out of you by events in environment
- Is the result
Operant Behaviour (4)
- May seem voluntary rather than automatic
- Behaviours you emit
- Produces a result
- Operates on the world
3 ways we learn new behaviours
- Observation
- Trial and Error
- Shaping
These are called Acquisition processes
Thorndikes Law of effect
Weakeners/Annoyers/Punishers —– Strengtheners/satisfiers/Reinforcers
Positive Reinforcement
Something is added or intensified
Strengthens approach and engagement behaviour
Negative Reinforcement
Something is removed, reduced or made inaccessible
Strengthens and maintains escape and avoidance behaviours (e.g umbrella = escape rain)
Primary Reinforcers
Have their strengthening property already
Secondary Reinforcers
Acquire their strengthening property by their association with primary reinforcers
Extinction
When response no longer produces reinforcers
Withhold reinforcers
Reverse the effect of initial conditioning
Punishment
May be positive of negative
+ve = pain inflicted
-ve = time out
Effect must be to suppress behaviour otherwise not a punisher
Unconditioned Stimulus
Is one that unconditionally, naturally, and automatically triggers a response
This response requires no learning, it simply happens automatically
Conditioned stimulus
Previously neutral stimulus that, after becoming associated with the unconditioned stimulus, eventually comes to trigger a conditioned response
Conditioned response
An automatic response established by training to an ordinarily neutral stimulus.
Dark Adaptation
Adjustment of the eye to low light intensities, involving reflex dilation of the pupil and activation of the rod cells
Light Adaptation
Contraction of the pupil, adaptation to increase illumination
