Psych 240 Exam 1

Introspectionism

understand the mind through consciously intreperting mental processes

Wilhelm Wundt

Categorized thoughts in terms of introspectionism (organ, # of sensations)

Edward Titchener

Problems with Introspectionism

1. Is it reliable? Inner head thoughts can't be replicated or validated because it was just his thoughts so we don't know if they are accurate/verified - need data that another person can reproduce.

2. It's a private/personal/subjective experience.

3. We ourselves don't have access to everything in our heads, we aren't aware of the mechanisms that cause thoughts and realizations.

Behaviorism

Since we can't look inside our heads, we focus on the stimulus and response it causes, and make an association between the two so someone else can do the same experiment.

Ivan Pavlov

Interested in digestion and Nobel Prize in physiology (salivation of dogs)

John Watson

Most extreme behaviorist - not only can we NOT see in the black box, but there isn't much going on in there (all thought is just stimulus response) - thought is a sub vocal speech, don't have to worry about memory or other difficult terminology.

B.F. "Fred" Skinner

Moved psychology to be rigorous science that other people could replicate and results could be verified, emphasis on what anyone and everyone can observe - tried to explain all of human behavior in terms of stimulus response behaviors and which ones change based on reinforcement

Problems with Behaviorism

1. Ignores what goes on in the black box

2. Can't account for diversity of human behavior - language isn't just a response, it's learned

3. We can't directly observe all data, there are other theories that have extreme explanatory power (ex. memory can't be directly observed, but plays a huge role)

Cognitivism

We recognize we can't look at what's going on in there but we can hypothesize about the mechanisms and test the predictions of what stimuli lead to what responses - see if results happen the way we predict

Much of human behavior can be understood in terms of how people think - synthesis of behaviorism and gestaltism

Computational view of mind & Information processing

Key feature/historical moment of cognitivism - maybe human mind is like information processing computer, can do so much more/is more general - taking information in and doing computation on its own, then spitting out results (some people are hard core materialists saying that we are machines, other don't take metaphor as seriously)

Dependent Variables

The changing variable (what is being measured/analyzed - the output) as a result of manipulating independent variable

Ex. reaction time, accuracy, brain activity

Independent Variables

The manipulated variable (what you manipulate/the stimuli that causes the result)

Main Effects and Interactions

Changing an independent variable affects the dependent variable - graphically it could affect the slope (the dependent variable is changing because of your manipulation)

Graphically: If there's a horizontal line it means there is no main effect**

Interaction occurs when the effect of one variable has depends on another independent variable

Graphically: If the independent variable lines are parallel, there is no interaction**

Mental Chronometry

Donders invented Mental Chronometry (the study of the time course of mental processes) assuming that our minds work in stages (like algorithms/information processing computer) - stimulus comes in, processing stage, more processing, response - we receive information from previous stage and transforms the information to send to the next stage)

What are the process stages doing, though? - Donders tried answering how long each stage takes through simple tasks (detection vs. choice)

Simple reaction time

Detection - sit there and press a button whenever you see a light (measure how long it takes to press the button)

Choice reaction time

Choice - press button if you see green light, press a different button for red light (measure how long that decision takes) - and compare reaction times

Donder's Subtraction Method & Problems

Assuming that it's pure insertion/subtraction, adding all stage times - but what if all stages operate on parallel levels/underestimate how long decision takes (ignore decision process that happens during the detection itself) - adding a new processing stage does not affect other processing stages

Can argue there are other stages (ex. memory look up to figure out what color is green)

Problem with confirming evidence

There's natural human tendency to stick with what seems to work and look for evidence in favor current beliefs - extremely important to try to disprove hypotheses rather than just accepting one because it seems to work

Encoding

Difficulty getting the information in (getting gas into the car) - trouble getting the experience into the memory box

Storage

Information gets in, but have hard time storing it over a delay (leak in the gas tank)

Retrieval

Hard time getting information when we need it - it's there and stored over a delay but we can't get the gas to the engine

Huppert & Piercy Amnesia Experiments

Two groups of participants - one healthy and other have Korsokoff's syndrome a.k.a. problem with memory - How does memory problem affect the three stages of how people remember things - Encoding/Storage/Retrieval?

Show participants pictures and ask to do recognition test, then show them pictures (giving amnesic patient more time to study to equate performance) and wait several days - after that there is almost no difference between the two groups

Falsifying Storage Explanation

If there was a problem with storage then amnesic patients would probably decline over time because they can't retain that information, but doesn't happen - if everyone knows 80% of the pictures and there is a hole in the gas tank then it should be getting worse over time/delay but they remember the same 80% after 10 minutes/1 day/3 days

Perception

The means by which information acquired from the environment via the sensory organs is transformed into experiences of objects, events, sounds, tastes, etc.

Distal Stimulus

The thing out in the environment that we are trying to perceive at a distance from us

Proximal Stimulus

When you sense something, it castes an image on the retinas/pattern vibration on the ear drums/pattern indentation on our skin when we touch (close to us) - pattern that the distal stimulus makes on our sensory organs

No direct access to that object but rather the image near us

Percept/Representation

Internal mental representation of what it is we perceive (domain of psychology)

Lack of Correspondence

What we perceive is not an accurate representation of what is really out there (percept does not correspond to distal stimulus)

Ex. Perceptual illusions

Paradoxical Correspondence

Vast majority of the time our perception is great, correspondence between proximal stimuli doesn't correspond to distal stimulus but the percept does (surprising) - paradoxical because there's a mismatch

Ex. Moving objects (proximal stimulus keeps object stationary but our perception is what we see when the object is moving, we recognize that it is moving even though proximal stimulus doesn't register it as so)

Perceptual Constancies

Our perceptual system often manages to perceive perceptual features as being constant despite the fact that there's change in the proximal stimulus (ex. size constancy/color constancy/shape constancy)

• Type of paradoxical correspondence in which our perception of the size of an object remains the same even though the object is getting closer, therefore projecting a larger proximal stimulus

Direct Perception (Stimulus Theory)

J.J. Gibson - environment provides all necessary cues because our brain was made to perceive the important and subtle cues to get an accurate percept - information coming from the environment is unambiguous

There is only one perception that can come of it, prewired brain to extract this kind of information

Constructivist Theory

Perception uses the data that comes from external view, but our knowledge and expectations play a critical role in what we perceive - not just based on external cues, but also what we already know about the world and expect to see

Sensory information can be ambiguous and our knowledge further defines it

Bottom-Up Processing

Refers to processing that is driven by the distal stimulus, stuff coming from the environment rather than stuff in your head

Top-Down Processing

Driven by knowledge and expectations

Direct Perception Theory: Bottom-Up or Top-Down?

Bottom-Up

Constructivism Theory: Bottom-Up or Top-Down?

Both

Paradox of Depth Perception (Paradoxical Correspondence)

Real world is presumably 3D (has depth) but our retina is flat and image casted by the room is flat on our retina - yet we accurately perceive 3D

We manage to see depth even though our retina doesn't have the ability to cue that information - shows brain has developed a depth perception cue

How the Visual System Recovers Depth

Visual depth cues (monocular and binocular)

Monocular Depth Cues

Can see depth with one eye, represented in two dimensions and observed with one eye

Binocular Depth Cues

Need both eyes to see depth, represented in three dimensions and observed with both eyes - use relative positioning of your eyes positioned far enough apart to provide two kinds of information to your brain:

Binocular disparity (two eyes send increasingly differing images to the brain as objects approach you)

Binocular Convergence (two eyes increasingly turn inward as objects approach you)

Linear Perspective: Monocular or Binocular?

Convergence in the horizon at some point in the distance, the closer they are to converging - the further that object is

Monocular

Shape Cues/Texture: Monocular or Binocular?

Closer they are, the more defined the shape - further away, they become shallower

Monocular

Relative Size: Monocular or Binocular?

Monocular

Interposition: Monocular or Binocular?

If something is obstructing your vision/in the way of your sight of something, it's closer to you

Monocular

Shadows: Monocular or Binocular?

Light comes from above (built in assumption) - light on bottom means it's going in

Monocular

Retinal Disparity: Monocular or Binocular?

Two fingers, one closer and one further - closer finger seems like it keeps moving, disparity between where the image is casted on both retinas - the more disparity, the closer it is

Binocular

Accomodation: Monocular or Binocular?

Change the shape of the lens in order to focus on something close or something further away (tend to make the lens flatter to focus on something further away, something close will make lens wider) - brain detects what the muscles are doing and sends signals to interpret

Monocular

Convergence: Monocular or Binocular?

Something close to me, my eyes will rotate inwards to focus, if something is far - it is more parallel - sends signals (are they converging or are they parallel)

Binocular (relationship between the two eyes are critical)

Retina

Sheet of cells at the back of eyeballs (more peripheral parts of nervous system)

Contains ganglion cells at the front, bipolar cell layer in the middle, photoreceptor layer in the back

Why do we have blind spots? (Where optic nerve is, which is where ganglion cells are connected) When light hits, ganglion cells need a tiny hole where bipolar cells and photoreceptors don't block access to send information the the brain (that is the blind spot)

Photoreceptors

Only cells in the body that get exposed to light like this - excites and fires signals forward through bipolar cell layers and ganglion cell layers

Build with a photo-chemical reaction inside so whenever it gets hit by light it causes a reaction

Rods & Cones

Rods (photoreceptor)

Black and white vision, just detects brightness (lot in the periphery) - helpful in the dark and really sensitive to light

Cones (photoreceptor)

Respond to color, concentrated in the fovea (when you're directly looking at something)

Needs a lot of light and only fires signals when its bright enough

Three types: Blue, Green, Red - perceiving all different colors by different combinations of cones

Ganglion Cells

Neuron/Brain cells - output cells of the retina - first layer of neuronal tissue closest to front surface of the eye whose axons constitute optic nerve

Neuron

Brain cells with three major parts: dendrites, soma, axon

Dendrites

Branches that are like the input processes (lots of them)

Soma

Cell body, where nucleus is located

Axon

Output process of the cell (one major branch)

Resting Potential

If you stick an electrode inside of an axon and outside (measuring charge) - there is a difference

Action Potential

When signal fires, resting potential changes - difference in charge reverses so that there is more positive charge on outside than inside

"Spike" in the neuron

Threshold

Potential must get above threshold to become an action potential

All-Or-None

If potential gets above threshold, it fires completely - otherwise it doesn't fire at all

Propagation

Active process down the axon - once past the threshold

Refractory Period

Once a neuron has generated an action potential and moved down axon, there is a short period of time where it can't fire again - reset period to get back to resting potential

Neurotransmitters

Chemicals used to communicate from one neuron to another