Week 1 Flashcards
cognitive psychology
the scientific investigation of human mental processes
or
the way humans interpret their environment, process infom and form responses
(how does the brain work and how do we think and process info)
what model does cognitive psyc use
information processing model
* perception is mostly vision
* through senses we take information, take representation, to output
how do we aquire knowledge
sensation, perception, attention,
how do we store knowledge
memory
how do we use knowledge (4)
reasoning, problem solving, decision making, language
sub areas of cognitive psyc
perception: how we take info from environment
attention: allocation of resources
memory: how we store info and retrieve it
language: how we trasnfer info to others
reasoning: how we derive info from what we already know
problem solving: how we gain information
applications of cognitive psychology
- improving training and learning
- analyzing how people do things
- improving object design
- improving computer interfaces
- improving written and spoken materials
- testing the assumptions of economic models
- figuring out what sort of car people will want to drive
history of Cognitive psyc - philosophy
Period: ancient greece to now
Question: where does knowledge come from
* nativism: born with it
* empiricism: we learn it
Method: discussion
Significance: assumption that psychology could be productively studied
problem: can’t test a theory with discussion
example: eyes and stability
* argue that eyes remain steady to see things clearly but eyes are always moving
Psychologists = philosophers + physicists
scientific method to study the mind
* making predictions and theorizing the underlying processes
empiricism: psych came from this idea
* knowledge stems from experience
* can be studied with experimentation and observation
* we can take a strict approach and study something that’s illusive
how do you measure something you can’t see?
Donders and Reaction time = first cognitive experiment
* first to demonstrate the mental processes are not instantaneous
he measured how quickly people reacted to light by pressing button
* he showed that the time it takes to make a decision can be measured
history of cognitive psych - Introspection
1800s to 1920s
Introspection: not a scientific approach but a method
* ask people why and how they did something
significance: assumption that psychology was something we could productively study
questions:
* structuralism: what are the elements of knowledge
–> focused on breaking down mental processes into most basic components
* functionalism: everything u know is to survive – what is knowledge for?
Introspection
Structuralist: Wundt - wanted to exlain conscious processes and experience (periodic table of consciousness)
functionalist: William James - wanted to know how the mind functions and adapt to new circumstances
Introspection - problem
can’t test a theory with subjective observations
- some things are not available to consciousness
- training biases what people report
- some processes happen so fast they can’t be reported
basically we don’t know what were thinking
* its a best guess
introspection example
how do your eyes move when you read
- most people have the impression that their eyes move smoothly across the page
- this impression is wrong - eyes move in saccades (little jumps) followed by periods of fixation (stability)
history of cognitive psych - behaviorism
behaviourists say that you can’t study the mind
significance: unconcerned with thought, mind, consciousness
* focused on observable & quantifiable behavior
question: how is behaviour learned?
- theory was that if u can control simple behaviour and have a theory for learning, you can predict complex behavior
main focus: using data
method: experimentation
John Watson: proposed that only behavior is objectively observable
* little albert experiment
B.F. Skinner: saw behaviourism as a philosophy of the science of psychology
* rat in box
behaviourism
- believed that all behavior could be broken down into simple lawful relationships between stimulus and response
- everyone started off with a blank slate (Tabula Rasa) and could be trained to do anything
- humans abilities were no different and were simply scaled up versions of rat, cat, or dog responses
our experiences lead us to have different behaviors in reaction to our behavior
- pavlov and dog operant conditioning
downfall of behaviorism
Language: it is generative and can not be accounted for by stimulus - response - reward notions of behaviorism
* where do you learn the recognition response?
real-world problems: practical problems in ww2 could not be addressed by behaviourist theories
* pilots experienced information overload and would often result in crashes
* experiencing information overload
History of cognitive Psych - the Cognitive revolution
Newell & Simon: compare humans to computers (metaphor)
Chomsky discusses language as inherited rule-governed system (theory of processing accounts for language acquisition)
Miller presents his work on short term memory
* limited capacity in how much information can be stored and processes
rise of cognitive psychology
1960s to now
question: what information fo people store and process
method: observe behavior
* experimentation
* correlations, verbal protocols, neuroimaging, computer modelling
computer metaphor
envision humans as information processing systems
examined how the computer worked to get ideas on how humans worked
representation: things your looking at, knowledge, experiences
* stored information
Processes = how do move info around, change and access it, and make predictions from it
* a program that takes information as input and transforms it as output
example of computer metaphor
remembering a short list of items to buy at the store
* representations: a few items
* process: rehearsal
computer metaphor is helpful in encouraging new way of thinking about what goes on in the mind
- computer breaks down information in binary - number 4 represented as 100
the mind stores information as patterns of neural activity which have an unknown correspondence to the stimuli world
the mind & cognitive psych
creates mental representations and controls mental functions
- creates and control mental functions
- role = to determine mental abilities
- creates representations so that we can act to achieve our goals
cognitive psych: study of mental processes which includes how the mind operates
first cognitive psychology experiment
Donder - how long it takes to make a decision
significance: mental responses cannot be measured directly but must be inferred from behaviour
Wundt’s psychology lab
Wundt’s approach: structuralism
structuralism: our experience is determined by combining basic elements of experience called sensations
perception = the adding up of sensations
created periodic table of the mind
used analytic introspection
* procedure where people describe their experience and thought processes in response to stimuli
Structuralism was not fruitful and was abandoned
Ebbinghaus’s memory experiment: what is the time course of forgetting
Student of Wundt?
researched how quickly learned info is lost over time
quantitative method: did experiment of remembering on himself
used a measure called savings: to find magnitude of memory left from initial learning
* higher savings = greater memory
longer delays = smaller savings
savings curve: plot of percent savings vs time after original learning
* shows that memory drops rapidly for the first two days after the initial learning and then levels off
* showed that memory could be quantified
William James
not a student of Wundt
- taught Harvards first psychology course
- based on observations of his own mind
- observed that paying attention to one thing involves withdrawing from other things
- negative reaction to Wundt’s technique of analytic retrospection –> major force that caused psychology to reject the study of mental processes
Early pioneers in cognitive psychology
Donders
* simple vs choice reaction time
* decision takes 1/10th second bc thats how long choice takes
* first cognitive psychology experiment
Wundt
* analytic introspection
* not reliable results
* established the first laboratory of scientific psychology
* structuralism
Ebbinghaus
* savings method to measure forgetting
* forgetting occurs rapidly in the first 1-2 days after original learning
* quantitative measurement of mental processes
James
* no experiments; reported observations of his own experience
* descriptions of a wide range of experiences
* first psychology textbook; some of his observations are still valid today
* functionalism
Watson founds behaviorism
Behaviorism: approach says that observable behavior provides the only valid data for psychology
consequence: makes consciousness and unobservable mental process not worthy of study by psychologists
wanted to restrict psyc to behavioral data (like Donder’s reaction times)
- little albert
ideas associated with classical conditioning
Pavlov’s pairing of food with a bell caused dog to salivate to sound of bell
skinner’s operant conditioning
type of conditioning championed by B.F. Skinner, which focuses on how behavior is strengthened by presentation of positive reinforcers or withdrawal of negative reinforcers
interested in behavior
idea that behavior can be understood by studying stimulus-response relationships influenced a generation of psychologists
Tolman
cognitive map
* conception within the rat’s mind of the maze’s layout
* mental map indicated that when starting from the new location it needed to turn left to get food
idea that something other than stimulus-response connections might be occuring in the rat’s mind
computers
computers process information in stages
psychologists proposed the info-processing approach to studying the mind
* traces sequences of mental operations involved in cognition
* the approach where the mind is described as processing information through a sequence of stages
studying higher mental processes
model of memory (Atkinson and Shiffrin)
* flow of info in memory progesses through 3 stages
- sensory memory holds incoming information, then to short term (few seconds) then to long term
distinguishes between different components of the memory process
Studying the physiology of cognition
Neuropsychology = study of behavior of people with brain damage
electrophysiology = measuring electrical responses of the nervous system
PET - brain imaging
* positron emission tomography
* expensive and have to inject stuff
limitations to fMRI research
levels of analysis of behavior
idea that the topic can be studied in a number of different ways
- measuring behavior can be analogous to measuring the car’s performance
- measuring the psychological processes behind behavior is stuff under the hood
early conception of neurons (Cajal)
nerve net: network of continuously interconnected nerve fibres connected by synapses
neuron doctrine: idea that individual cells transmit signals in the nervous system and that these cells are not continuous with other cells
neural circuits: interconnected neurons
neural representation and cognition
neural representation: states that everything a person experiences is based on representation in the person’s nervous system
feature detectors
feature detectors: neurons that respond to specific features, such as orientation, size, or the more complex features that make up environmental stimuli
experience-dependent plasticity: mechanism that causes an organisms neurons to develop so they respond most to stuff exposed to them alot
* structure of bran is changed by experience
* if someone has mainly vertical sensitive neurons, the kitten perceived only verticals and a similar result occurred for horizontals
visual cortex: area in the occipital lobe that receives signals from the eyes
Neurons that respond to complex stimuli
Hierarchical processing
* neurons that respond to simple stuff send their axons to higher levels of the visual system and then to higher areas
sensory coding
sensory code - how many neurons represent different aspects of environment
specificity coding - idea that an object could be represented by the firing of a specialized neuron that responds only to that object
* unlikely to be correct
population coding - representation of a particular object by the pattern of firing a large amount of neurons
sparse coding - neural coding based on the pattern of activity in small groups of neurons
representation: neurons and groups of neurons contain information for perception, memory, and other cognitive functions
localized representation
basic principle of brain organization is localization of function – specific functions served by specific areas of the brain
- many cognitive functions are served by the cerebral cortex
- other functions are served by subcortical areas
localization determined by neuropsychology
cortical equipotentiality: idea that the brain is operated as an invisible whole as opposed to specialized area
Broca’s aphasia
* damage to Broca’s area in frontal lobe
* can’t understand some types of sentences and labored and ungrammatical speech
Wernicke’s aphasia
* damage to temporal lobe
* produce fluent and correct speech but its not coherent
* meaningless speech
- shows that different aspects of language are served by different areas of the brain
other neuropsychology - damages/purposes
damage to occipital lobe = blindness
* where visual cortex is
auditory cortex: upper temporal lobe, hearing - signals from ear
somatosensory cortex: parietal lobe, responsible for perceptions of touch, pressure, pain - signals from ear
frontal lobe: coordination of senses, thinking & problem solving - signals from all senses
Prosopagnosia = inability to recognize faces
* can tell a face is a face but can’t recognize whose face
double dissociation = occurs if damage to one area of the brain causes function A to be absent while function B is present and vise versa
distributed representation
different areas respond to different features of humans
* principle of cognition: most of our experiences is mulitdimensional
- even simple experiences involve combinations of different qualities
looking at a face
* triggers responses to many different aspects of the face
* we also respond to – where someone is looking, how attractive a face is, if the face is similar, how parts of the face move
distributed representation
* looking at a face activates many areas of the brain
* other examples are remembering, and producing & understanding language
remembering
episodic: memories for events in life
Semantic: memories for facts
producing and understanding language
Wernicke: language goes beyond isolated regions to include connections between them
nonlanguage functions are associated with parts of Broca’s area
* processing of sentence grammar occurs throughout language system
neural networks
interconnected areas of the brain that communicate with each other
structural and functional pathways
there is resting state of brain activity – so brain is always active
structural connectivity
brain “wiring diagram” created by nerve axons that connect different brain areas
- track-weighted imaging
—based on detection of how water diffuses along the length of nerve fibers
functional connectivity
the extend to which the neural activity in separate brain areas correlate with each other
- method to determine whether the responding of two areas is correlated is based on resting-state fMRI
6 functional networks determined by resting state fMRI
network, visual, somatomotor, dorsal attention, executive control, salience, default mode
the default mode network
a network of structures that respond when a person is not involved in specific tasks
areas in the frontal and parietal lobes that decrease activity during tasks have correlated resting state activity so they are part of a functional network
How to study
Chunking - experts who show high level of performance chunk up info
fluency illusion = feels like u know info but don’t
quantitative methods
correlational methods
* correlations: two variables change together
* goal: predict one variable based on another
* knowing state of one variable can predict state of the other
Experimental methods
* goal: infer that changes in one variable cause changes in another
* if variable changes how does it affect the other
Hypothesis
science centers around this
hypothesis: testable explanation of a phenomenon
* theoretical framework for what you think might be going on
theories and not facts
* testing what the probability is that the theory is correct
good theory = hypothesis can be shown to be wrong (if it can’t be proven wrong, its not useful)
causal direction
things that make a variable increase or decrease
* problem is that there could be another variable that would be causing them to be increasing or decreasing together
alternative variables
have to account for these bc could be causing the causal relationship and not the variable you thought
inferring causality
experiments involve random assignment
* correlational studies do not
randomly assign to
* reduce bias in sample
* any variability gets equally distributed
* the variance gets added to error
confounding variable
variable that correlates with the independent variable
- still have confounds when you randomly assign
when there is a confounding variable, either it or the IV could have caused the effect
* example: sleep deprivation
* solution: control for sleep, by excluding people who get less than six hours
——when u add control variable, can take away confound
neuron
cell body with nucleus
Dentrites come off cell body
axon (long part - Myelin sheath protects)
leads to arborizations which end in terminal buttons
- intensity by rate (low intensity = slow firing)
- rate of firing determines AP which determines when something is more intense
Synapse and neurotransmitters
- synapse allows firing from one neuron to the next to either ampliy or decrease the signal
- just because of neuron fires, doesn’t mean the other will fire more if the connection is inhibitory
- synapse can be modified to make the signal go by smoother or to disrupt the signal
neurotransmitters
* excitatory: increases chance neuron will fire (acetylcholine)
* inhibitory: decreases change neuron will fire (GABA)
cortex divided into four areas
frontal: reasoning, planning, emotion
temporal: hearing and memory
Parietal: perception of touch, pressure, temperature, pain
occipital: vision
two key principles of cortical functioning
- contralateral
- hemispheric specialization
contralateral
control centers for one side of body is controlled by the opposite hemisphere of brain
the visual field is contralateral
* stuff on right side of visual worlds goes to left side of brain
- processing contralaterally but according to what’s out there in the real world, not according to anatomy
hemispheric specialization
structurally but not functionally symmetric
- language is all on left side
- imagery = right side
left side is more analytical and right side is more artsy and free willing/creative
ability to verbalize = when left side is used
localizing brain function
what do different brain regions do
parts of brain are specialized for certain functions
methods for localizig brain function
* lesions
* electrical recording
* imaging
lesion studies
case studies
observe behavioural ability given neurological deficit
limitation: if you disrupt a certain area it could be disrupting the pathway to the section of the brain that does the action so it might actually be controlled by a different area of the brain
* can’t generalize
localizing brain function - Electrical recording single cell
electrical recording: Single cell
* animal studies, record activity of single cell while performing task
limitations: animal brains not human
* won’t tell you how much brain function and can’t study language with animals
Localizing brain function - electrical recording event related potentials
electrical activity recorded with sensors on scalp
* activity recorded in response to a stimulus over multiple presentations – result is an event related potential – electrical activity associated with the stimulus
eeg: measurement across the whole scalp
limitations: really good at temporal but bad spatial resolutions
* can’t tell where in the brain this is happening
localizing brain function - Functional imaging (PET)
Indirect measure of neural activity – injected with radioactive oxygen that is concentrated in areas that consume more blood
resolution: spatial good, temporal bad
limitations - we have better methods bc both temporal and spatial are bad
localizing brain function: MRI
measurement of cerebral blood flow
oxygenated and deoxygenated blood have different magnetic properties
machine measures ratio to indicate areas of greatest oxygen usage
* fMRI shows functional part
* gives structure of the brain (black and white)
resolution: spatial good, temporal bad (worse than PET)
limitations: looking at blood
* takes while to perform a task before you start seeing changes in the functional regions to get big changes so its not so great for temporal resultion
localizing brain function - Transcranial mgnetic stimulation
apply very strong and direct magnetic field to a region of cortex
all axons fire at once with this pulse
creates temporary lesion in brain so that area of brain won’t work
limitations: don’t know the long term affects, you can make someone blind or arm go limp
works well on surface just for lobes
converging methods to localize brain function
different methods have different short comings
using different methods to localize a function will eventually converge on the parts of the brain that support the function
modular view of function: certain parts of the brain are dedicated to specific types of processing
