PSYC 1100 Exam 3

Encoding

process of information + stimuli into an enduring memory

Storing

process of maintaining information in memory over time

Retrieving

process of bringing to mind information that was previously encoded

Neural code - short term memory

dynamic - pattern of activity among a group of cells

Neural code - long term memory

structural - pattern of connections within a group of cells

Trace consolidation

- what happens during elaborative rehearsal

- memory changes from dynamic to structural pattern (short term to long term)

Amnesia

loss of memory due to trace consolidation being interrupted

Retrograde amnesia

forget info that occurred before accident / surgery

anterograde amnesia

forget info that has happened after accident / surgery DUE TO inability to form new memories

Forgetting in the STM

- Displacement

- Decay

Displacement

cannot hold unlimited items in STM, so something gets booted out (and you forget it)

Decay

fading away of info due to lack of rehearsal

Forgetting in the LTM

- misplacement

- retrieval failure

Misplacement

- info is still in the brain, but not accessible

- may attach info to wrong context

Retrieval failure

- the inability to recall long-term memories

- lacking retrieval cues

Interference

old and new information compete with one another, making it harder to remember something

Proactive interference

- old info affects new

- ex. learning to drive manual and then switching to automatic = keep trying to use the clutch

Retroactive interference

- new info affects old

- ex. learned about American Revolution and then Civil War, on test remember Civil War only and mistaken events for Revolution

Working memory

- what you're working on at the moment

- brain's workbench

- limits on processing information ex. multiplying large digit numbers

Depth of processing

- deeper processing makes info more memorable

Elaborative encoding

- putting meaningful connections to info in order to remember

- often by attaching it to previous learning or other concepts

Elaborative rehearsal experiment: visual

- Q: is this word in capital letters?

- looking at words

- shallow processing

Elaborative rehearsal experiment: acoustic

- Q: does the word rhyme with ...?

- how the words sound

- intermediate processing

Elaborative rehearsal experiment: semantic

- Q: what is a synonym for this word?

- meaning of the word

- deep processing (best)

Explicit / declarative memory

- conscious

- prior learning experience

- able to declare the memory

Two types of explicit / declarative memory

- Generic / semantic

- Episodic

Explicit memory tasks in a study

- recall: what were the words on the list you read?

- recognition: circle the words you saw on the list

Implicit memory

- unconscious

- unaware that we know this information

Two types of implicit memory

- priming

- procedural

Implicit memory task in a study (priming)

- priming: making a response easier to do without subject's awareness

- show "nurse" on screen, primes subject to respond faster to "doctor"

Implicit memory endurance & depth of processing

- implicit memory lasts longer than explicit

- depth of processing (visual, acoustic, semantic) does not affect implicit memory - it is affected the same by each

- depth of processing only affects explicit memory

Implicit memory tasks

- stem completion: more likely to finish word with whatever they saw previously

- word fragment completion: if shown word earlier, more likely to solve fragment

- unaware that they saw the word beforehand!

Generic / semantic memory

- facts, concepts, numbers, meanings

- ex. capital of Arizona

- explicit

Episodic memory

- events and episodes of your life

- time and place

- ex. first day of classes

- explicit

Procedural memory

- implicit

- how to do something

- don't usually have to think about it, but if asked, can be broken down into steps

- ex. typing, brushing teeth

Patient HM

- had hippocampus removed to reduce seizures

- lead to inability to create new memories = anterograde amnesia

- unable to form new explicit / declarative memories

- was still able to make new implicit / procedural memories

Patient HM star drawing experiment

- improved his ability to draw the star over time

- showed he could still make procedural memories

Memory tasks: Amnesiac patients vs control groups

- amnesiac patients perform worse on explicit tasks

- amnesiac patients perform the same as control group on implicit tasks (such as star drawing)

Encoding specificity principle

- to retrieve a memory, best if context at retrieval is the same as context at encoding

retrieval cues

- stimuli that helps retrieve a memory

- should be related to context of memory

Scuba diving experiment

- best retrieval = learned AND retrieved in water, or learned AND retrieved on land

- if learned on land and retrieved in water, not as good (vice versa)

Loftus and Palmer retrieval experiment

- participants asked with word "smashed" vs "hit" more likely to report there was broken glass in the image, even though there wasn't

- this is a false memory

- shows: memory can be reconstructed and distorted by other info and external influences

Sensation

- basic mental state responding to energies in the environment

- experience of the world

- ex. light, sound

Perception

- mental state responding to properties of objects and events in environment

- knowledge of the world

- ex. see green stuff and know that it's grass

Doctrine of specific nerve energies: Muller

- quality of sensation (visual, auditory, touch) depends on which nerve fibers are stimulated

- ex. optic nerves are stimulated by light

- every sensory experience must have a corresponding set of nerve fibers

Light = electromagnetic radiation (wavelengths)

- intensity of color = brightness

- wavelengths = colors (our brain sees wavelengths and interprets color)

- short wave = blue

- medium = green

- long = red

Photoreceptors

- type of cell in the eye that converts light into electrical signals that the brain then interprets as vision

- respond to light - in the retina, produce action potentials when stimulated

2 kinds of photoreceptors

- rods: low light, nighttime, black and white vision

- cones: bright light, daytime, color vision

3 types of cones

- short: sensitive to short waves such as blue

- medium: sensitive to medium waves such as green

- long: sensitive to long waves such as red

How signals pass through the eye

retina -- rods/cones (photoreceptors) -- bipolar cells -- ganglion cells -- ganglion cell axons / optic nerve -- brain

Opponent process theory

- 3 types of opponent process cells

- black/white: excited white, inhibited black

- red/green: excited red, inhibited green

- blue/yellow: excited blue, inhibited yellow

After images

- occur when when we see an opposing color after staring at an image for too long

- ex. looking at red and then seeing green on a blank screen = red cells are fatigued after constant firing

Trichromatic theory - Young and Helmholtz

- proposes three types of cones: red, blue, and green

- all colors are a mixture of these three

Retina

- photoreceptors

- bipolar cells

- ganglion cells

- rods more common in periphery

- cones more common in center, called fovea

Optic nerve

- nerve fibers that send visual info to brain

- creates a blind spot because there are no photoreceptors in this area

Fovea

- indentation at center of retina where cones are most prevalent

- most visual acuity = clearest vision looking something straight on

Lateral Inhibition

- neighboring receptor cells inhibit each other

- result: exaggeration of contrasts: dark looks darker, light looks lighter

Brightness contrast

- neighboring regions of different brightness have their edges sharpened as brightness/darkness difference is increased

- ex. in white and black box, the white part is firing the neurons more, which inhibits the neuron responding to the dark box, making it look darker

Neurons as feature detectors

- neurons respond to specific lines and shapes in the cortex

- some respond more to vertical lines, horizontal, etc.

Poverty of the stimulus

- the retinal image is inadequate for knowing about an actual object

- can only tell us so much info, but the rest is inferred from the brain

- this means perception happens in the brain, not the eye

Retinal image

- The image of an object that is projected on the retina

- everything is inverted - upside down and backwards

- these images are ambiguous - a close up small object has same retinal image as far away large object

- image on retina is 2 dimensional

Depth perception

- both eyes help uncover depth info

- our knowledge of depth comes from binocular disparity

- empiricism says: based on experience, we learn to perceive depth

Percept

retinal image + cues + knowledge from experience = percept

Monocular depth cues

- one eye

- linear perspective

- interposition

- relative size

linear perspective

- parallel lines appear to converge with distance

- learned from experience

Interposition

- an object that is closer blocks (occludes) the farther object

- ex. the head of the person in front of you blocks your view of a movie theater screen

relative size

- a near object casts a larger retinal image than a farther away object (when they are the same size)

Binocular disparity

the difference in the retinal images of the two eyes that provides information about depth

Unconscious inference

- best guess of what is going on in the world

- maximum likelihood of it being true

- answers: what is the distal stimulus that caused the proximal stimulus?

- perception is always in direction of best inference

- this is based on experience (empiricism)

Gestalt psychology

- nativist viewpoint - born with the ability for percept

- we take retinal image and add innate laws of organization

Principle of perceptual organization (Gestalt psychology)

- Proximity: objects close together are perceived as belonging together

- Similarity: similar objects are perceived as belonging together

- good continuation: tendency to perceive elements in a smooth, continuous path

- closure: if visual image is incomplete, our brain fills in the gap to perceive complete object

Apparent motion

- stimulus present in two locations within a short period of time is perceived as moving

- not actually moving

Gestalt program

1. perception is always in direction of the simplest configuration possible

- ex. in reversible figure-ground pictures, neither is simple so both are seen

2. the whole is different than the sum of its parts - perception of form is different from collection of sensations that make it

- ex. subjective contours are perceived without sensations