Psych 1100 Lecture Notes

Flashcards on Memory, Sensation, and Perception

Encoding

Process of transforming what we perceive, feel, or think into an enduring memory

Storing

Process of maintaining information in memory over time

Retrieving

Process of bringing to mind information that has been previously encoded

Short Term Memory:

Dynamic: pattern of activity among a group of cells

• Duration: Seconds to minutes

• Capacity: ~7 ± 2 items

Long Term Memory:

Structural- pattern of connections within a group of cells

• Duration: Relatively permanent

• Capacity: Possibly infinite

Trace consolidation:

From dynamic pattern to structural pattern→ elaborative rehearsal (adding meaning to this information): will help with putting the information into structural pattern.

making short-term memory into long-term memory

Consolidation increases in sleep when you recall the information, when you speak about the information, and when you practice the information

Amnesia

Trace consolidation is being interrupted

Retrograde amnesia:

Forget information that has occurred before the accident

Anterograde amnesia:

Forget information that has happened after the accident

Short Term memory when forgotten

is displaced or decayed

cannot hold a lot of information in short-term memory, so something will be bumped out of the short term memory→ displaced

information fades when you don’t do rehearsal→ decay

Long-term memory when forgotten

is misplaced or a retrieval failure

Information is still in the brain, but not accessible→ misplacement

not able to come up with the long term memory→ retrieval failure

Serial Position effect

• In free recall, people tend to remember:

  • Primacy effect: Items at the beginning

  • Recency effect: Items at the end

Proactive interference:

Long term memory: Old information affects the new information - getting in the way of the new recent information

Retrograde interference:

Long term memory: New information affects the old information - getting in the way of the old information

Working memory:

The information you are “working on” in that moment

constantly constructing meaning and thinking on that information

limits on processing information

ex: Might be able to multiply 2 digits by 2 digits in your head, but then if you were

asked to multiply a 8 digit number by a 9 digit number, you will not be able to

process that information

Elaborative encoding

Putting meaning and deeper connections to the information in order to remember this information

Elaborative rehearsal experiment:

Craik and Tulving (1975) Experiment:

First: subjects are shown a list of words

■ visual : looking at the words: shallow processing

● Is this word in all capital letters?

■ Acoustic: how the words sound: intermediate processing

● Does the word rhyme with_____?

■ Semantic: the meaning of the words: deep processing

● What is a synonym for this word?

○ What the experiment shows: deeper processing = remember the list of words more , can

recall the words better

Explicit Memory

Referring to prior learning experience (conscious) → what you think of when you think of memory

Recall: what were the words on the list you read?

○ Recognition: circle the words previously shown to you

Implicit Memory

Not conscious of remembering this information

Implicit Process

Priming : In general we are trying to see if we can make a response more easier to do

■ Ex: show “nurse” on screen which primes the subject to respond faster to “doctor” which shows

next

○ Task:

■ → first read a list of words and then do a task

● Stem completion: “MOT______”

○ If in the earlier words they were shown “motive”, they are more likely to say “motive”

to finish the word→ they are unaware of this

● Word fragment completion:” _U_O_O_I_E”

○ If in the earlier word they were shown a word, they will be able to solve the word

fragment because of the word they saw earlier in the list

Declarative memory (explicit)

Knowing information consciously and being able to say/ “declare” the memory (episodic or generic/semantic)

Generic / Semantic memory:

Remembering information like the capital of Australia or the list of brain structures you learned in psychology 1100. → information in the form or words or numbers

Episodic memory:

Remembering the first day of classes this semester → remembering an event/”episode”: who was there, where were you, what were you doing

Procedural Memory (implicit):

Memory on how to do something

ex: how to ride a bike is your procedural memory

Patient H.M.

Damage to critical brain regions (hippocampus) associated with memory

consolidation→ leads to inability to create new memories= anterograde

amnesia

★ H.M. had epilepsy and the doctor thought removing the hippocampus

would be the best idea:

○ Leads to anterograde amnesia = inability to form new (explicit/declarative) memories

★ Although he could not form new declarative memories, he was still able to

make new implicit/ procedural memories

○ Able to learn how to draw a star in the mirror→ no recollection of this, but has the

implicit procedural memory to perform well on drawing task

The Experiment with H.M. shows what type of memories he is still able to retain and what was the experiment?

Shows that as time goes on, the ability to draw the star in the mirror, got better and

better →

○ Therefore this shows that even though H.M cannot form new declarative memories, he can still make new implicit/ procedural memories

Encoding specificity principle:

to retrieve a memory it is best if the context at the time of retrieval is the same as the context at encoding

Retrieval cue:

Stimulus that helps retrieve a memory → retrieval cues should be related to the context that the memory was created in

Examples of encoding specificity principle:

Example:

◆ List of words: cats, dogs, monkeys, guinea pigs...→ a retrieval cue could be elephant ; NOT guitar

➔ Example:

◆ A scuba divers learn words on land or in the water

◆ Then they will be asked to retrieve those words in the water or on land

◆ Results:

● If they learn words on land and then retrieve on land= best retrieval

● If they learn words on land and then retrieve in the water= not the best retrieval

● If they learn words in water and then retrieve in water= best retrieval

● If they learn words in water and then retrieve on land= not the best retrieval

➔ Example: If you learn information that's going to be on exam in a certain seat, you are

more likely to do better on the exam when you sit in the same seat (small difference if

you study)

Loftus and Palmer Retrieval experiment

1.First shows participants images of a car accident (no broken glass in

images)

2. Then they were asked each group 1 of these questions:

a. How fast were they going when they “smashed” into each other?

b. How fast were they going when they “hit” each other?

3. Now a week later....

a. Asked if they remember they saw broken glass in the images: (no glass was

actually in the image)

i. If they were asked with the word “smashed”

1. More likely to say there was broken glass in the image

2. They would picture the broken glass in the scene

3. This is a false memory and it is because of the words (smash) that were

used when asked about the image previously

4. Conclusion: memory can be reconstructed and may be distorted by

other information

Sensation:

Basic, primitive mental state corresponding to energies in the environment; experience of world - light energy, sound energy - seeing blue, hearing a sound

Perception:

Mental state corresponding to properties of objects and events in environment; knowledge of the world

Seeing blue→ it’s the sky

Seeing green stuff on the ground → it’s grass

Doctrine of Specific Nerve Energies:

Quality of sensation (visual, auditory, touch) depend on which nerve fibers are stimulated

Fibers of optic nerve are normally stimulated by light:

★ Any sensory experience must have corresponding set of nerve fibers:

experience of color, brightness, loudness, pitch

Light: electromagnetic radiation

Intensity of color→ brightness

★ Wavelengths → color !! → we do not see color we see wavelengths and

our brains creates the colors

○ Short wavelength: blue

○ Medium wavelength: green

○ Long wavelength: red

★ Wavelengths are easily reflected → we evolved to use these wavelengths

to see

2 kinds of photoreceptors

rods and cones

Rods

Low light conditions - nighttime ; black and white only

Cones

Bright light conditions- daytime; color vision

3 types of cones: each respond to certain wavelengths

Short wavelength cones: sensitive to short wavelengths (blueish)

○ Medium wavelength cones: sensitive to medium wavelengths (greenish)

○ Long wavelength cones: sensitive to long wavelengths (redish)

Opponent process theory:

Stimulating black/white : when excited you see white, when inhibited you see black

○ Stimulating red/green : when excited you see red, when inhibited you see green

○ Stimulating blue/yellow : when excited you see blue, when inhibited you see yellow

After Images

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

■ Ex: when we stare at a red image for too long and look at a blank screen after, we often

see green because our red cells are fatigued after firing continuously for so long

Trichromatic Theory:

Thomas Young and Hermann von Helmholtz

All colors will be a mixture of blue, green and red based on the response of those cone types

Retina:

consists of photoreceptors, bipolar cells, and ganglion cells

• Rods are more common in periphery of retina (120 million total)

• Cones are more common in center of retina - in the fovea (6 million

total)

Optic Nerve:

Nerve fibers that send visual information to brain

Creates a blind spot because there are no photoreceptor cells here

Fovea:

Indentation (at center of retina) where cones are most prevalent

Most visual acuity = clearest vision (can see details and shapes best)

How signals travel in retina

Rods/Cones (photoreceptors)→ Bipolar cells → Ganglion Cells →

Ganglion Cells’ Axons/Optic Nerve → Brain

Lateral Inhibition:

Neighboring receptor cells tend to inhibit each other (using inhibitory interneurons to connect them)

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

➔ example: brightness contrast - neighboring regions of different brightness have their

boundaries sharpened as their brightness/darkness difference is increased

Neurons

act as a feature detector

Neurons respond to specific lines/shapes/details in the (cat) cortex:

➔ Some neurons respond more to vertical line

➔ Some neurons respond more to horizontal lines

➔ Etc

Perception

higher process in the brain. There’s something out in the world and we want to know about it

Distal Stimulus Vs. Proximal Stimulus

Distal Stimulus

• The actual object in the external world.

• It exists outside the body and is the source of sensory information.

• Example: A tree you're looking at.

Proximal Stimulus

• The sensory input that is registered by your sensory organs (like the image of the tree on your retina).

• It's the representation of the distal stimulus on your sensory receptors.

• Example: The pattern of light that hits your retina when you see the tree.

■ Distal image (thing in world ) —> reflected light —> proximal stimulus

Poverty of the Stimulus

The retinal image (proximal stimulus) is inadequate for knowing about the

object- “thing in the world” (distal stimulus)

◆ Its inverted - upside down and backwards

◆ These images on the retina are ambiguous

● A close up small object can have the same retinal image as the far away large object

◆ Two dimensional- image is 2D (flattened) on the retina so we need to uncover the 3rd

dimension

➔ So this obviously means that perception happens in the brain not eye!!

Binocular disparity

Two eyes help uncover depth information

➔ Depth is coming from the binocular disparity (difference in the two retinal images)

Empiricist View of Perception

Retinal Image + Depth Cues + Past Experience = Percept

Monocular Depth Cues (One Eye):

• Linear Perspective: Parallel lines appear to converge in the distance (learned from experience).

• Interposition: Closer objects block farther ones.

• Relative Size: Same-sized objects appear larger if they are closer.

“Unconscious Inference” (Helmholtz):

• The brain makes a “best guess” about what caused the retinal image.

• We perceive what is most likely to be true, based on past experiences.

Gestalt Psychology: nativist view (born with)

Gestalt Psychology: Perception is Built-In

Key Idea:
We are born with the ability to organize sensory input into meaningful wholes.

How it works:
Retinal Image + Innate Organizational Principles = Percept

🧩 Principles of Perceptual Organization:

• Proximity: We group things that are close together.

• Similarity: We group things that look alike.

• Good Continuation: We see smooth, continuous patterns.

• Closure: We fill in gaps to see complete objects.

percept

What your brain understands or "sees" after combining sensory input with past experience.

Apparent motion

stimulus present in two locations within short time interval is seen

as one moving stimulus

★ no moving stimulus though! (i.e., no sensations of movement)

Gestalt Program

1) Perception is always in the direction of the simplest, most economical

configuration - (based on equilibrium in supposed brain states!)

ex.: in reversible figure-ground pictures, neither is simpler so both are

seen

2) The WHOLE is different from the sum of the parts - perception of form

different from the collection of sensations that make it up

ex.: subjective contours are perceived w/o sensations

Hippocampus:

important for explicit and declarative memory

Electromagnetic Spectrum

• Gamma rays → X-rays → Ultraviolet → Visible light (400–700nm) → Infrared → Microwaves → Radar → FM → TV → AM

ganglion cells

neurons that transmit visual information from the retina to the brain, crucial for processing visual stimuli.

Hubel and Wiesel

• Studied cat visual cortex

• Found neurons that fire in response to specific line orientations (vertical, horizontal, diagonal)