Ch.1 Cognitive Psychology

Wilhelm Wundt

• first person reffered to as a psychologist (aka father of psychology)

• invented introspection

Introspection

Analyzing own sensations and reporting them as objectively as possible

• Problem: highly subjective

Ivan Pavlov

• Paired food with sound of bell and dogs began to salivate to the bell without any food

• External stimulus: bell

• Response: salivation

John Watson

Little Albert feared white rat by pairing it with a loud noise (fear conditioning)

Behaviorism

Only focuses on observable reactions to stimuli in the environment rather than subjective processes

• Believed it was inapprorpriate to theorize about unobservable components of mental life

Edward Tolman

Argued that animals are motivated to learn general layout of mazes by forming a cognitive map

When you let a rat inside of a maze to roam around

• Tolman argues: rat will learn maze

• Behaviorists argues: nothing will happen

Cognitive map

A mental representation of the layout of the external world

Chomsky vs Behaviorism

Chomsky argues that behaviorism cannot explain language, memory, attention, or problem solving

• Argues that humans have inborn ability for language meanwhile behaviorism argues that language is learned by reinforcement

Miller’s Magical Number 7

• People can hold about 7 items in mind (short term memory)

• First clear evidence of measureable mental capacity

Computer metaphor

Our cognitive processes work like a computer

• Both complex and multipurpose

• limited processing mechanism (i.e memory and attention)

Hermann Ebbinghaus

Conducted first rigorous studies of human memory on himself

• Used nonsense syllables to test memory and how long it took him to relearn them

Ebbinghaus forgetting curve

The forgetting usually happens immediately and then continues to decrease

Information Processing Approach

A framework for understanding cognition that compares the mind to a computer, processing through series of stages

1. Stimuli: info about stimuli is transported to sensory receptors then that info gets processed to the brain

2. Info gets decoded through multiple processing stages in our brain

3. Decision must be made about how to respond to stimulus after it is recognized

4. Deciding to respond then it must be sent as a motor command

Serial Process

processing information one step at a time

Parallel Processing

The ability to process multiple pieces of information simultaneously

• Neuron link

• Example: speaking a written word involves broca’s area, motor cortex, angular gyrus, visual area, wernicke’s area

Sternberg Task

Participants were given memory sets (size varied) and responded yes/no if number was in the memory set, they were measured on how fast they responded

• Serial processing model predicts linear increase as size of memory set increases

• Parallel processing model does not predict increase in reaction time

Speed accuracy tradeoff

When people are asked to respond quickly, accuracy drops, if asked to be precise then speed drops

• Faster responses = more errors

• Slower responses = higher accuracy

• Balance depends on task goals

Single cell recording

Electrical activity of individual neurons

• Invasive: used in animal or clinical cases (humans or epilepsy patients)

EEG (Electroencephalography)

Measures electrical activity in the brain using electrodes placed on the scalp

• Noninvasive method

• Tracks brain rhytmn and schyronized activity of neurons

• Advantage: tells WHEN something in the brain is happening

• Disadvantage: does not tell WHERE exactly it is happening in the brain

ERP (Event-related potentials)

Brain waves that are time-locked to the presentation of a stimulus, derived from EEG recordings

• Measures voltage changes in brain

• Does not require overt motor or linguistic response

• Advantage: shows WHEN a particiular brain activity takes place in response to an event

• Disadvntage: Does not show WHERE in the brain the process is taking place

fMRI

Neuroimaging technique that measures brain activity by detecting changes in blood flow

• Advantage: can map functions like language + vision

• Disadvantage: timing is too slow to track split-second processes

Positron Emission tomography (PET)

Neuroimagining technique that measures brain activity by detecting distribution of a radioactive tracer

• Different tasks show distinct activity patterns

• Similar to fMRI in technique and timing

Transcranial Magnetic Stimulation (TMS)

Uses magnetic pulses to stimulate or inhibit brain activity in specific regions

David Rumelhart

developed models of learning and thinking that he describes as connectionist network models (AKA parallel distributed processing models)

Distributed Representations

Info is coded as a pattern of activation distributed across many different nodes

Associationism

the theory that mental processes operate through associations between ideas or sensations

Cognitive Neuroscience

The interdisciplinary study of the neural basis of cognition

Cognitive Revolution

A period in the mind 20th century marked by a shift away from behaviorism towards the study of cognitive processes

Top down processing

emphasizes importance of concepts, expectations, and memory in object recognition and other cognitive tasks

• requires higher level cognition

Bottom up

emphasizes the importance of information from the stimuli registered on your sensory receptors

• uses only lower level sensory analysis