PSY 224 Chapter 1 Slides

Wilhelm Wundt

Father of psychology and invented the method of introspection

Problem with introspection

Too subjective

Rise of Behaviorism

Ivan Pavlov and John Watson

Neo-Behaviorism

Edward Tolman: argued animals are intrinsically motivated to learn the general layout of mazes by forming what he called a cognitive map

Chomsky vs. Behaviorism

Chomsky argued humans must have an inborn ability for

language. Proposed an innate 'language acquisition device'

Miller’s Magical Number Seven

George Miller’s 1956 talk introduced the idea

that short-term memory holds only about 7

items, plus or minus 2. This showed that the mind

has measurable processing limits, just like a

computer with limited memory capacity.

Hermann Ebbinghaus

conducted the first rigorous studies

of human memory on himself; He was especially interested in forgetting.

Cognitive Psychology

branch of psychology that studies how we

perceive, attend, recognize, remember. Essentially what happens in our minds.

Information Processing Approach

Cognitive psychologists try to specify how information is

internally represented. All our  mental activity is about something

Parallel Processing

simultaneous, with a lot happening at the very same time

Serial Processing

is sequential, one process gets completed before the next one begins

Sternberg Task

• Give participants “memory sets” (e.g., “3, 9, 7”)

– Vary the size of the memory set

– Probe memory with targets and foil digits

– Respond “Yes/Present” if the probe was in the memory

set

• (e.g., 9 would be a Yes response because 9 = target)

– Respond “No/absent” if the probe was not in the set

• (e.g., 5 would be a No response because 5 = foil)

– Recorded how quickly the response was made

Typical Sternberg Results

Plot reaction time as function

of memory set size and type of

trial (targets/foils)

• The time needed to recognize

a digit increases with the

number of items in the

memory set

serial information processing model

predicts a linear increase as the size of the memory set increases  each additional digit in the memory set adds about 40 ms of decision making time because you are searching through the whole set. Note, that search continues through a match is generated midway

EEG (Electroencephalography)

• EEG is one of the most widely used noninvasive brain methods.

• It picks up synchronized activity of neurons at the scalp (tracks

brain rhythms (e.g., alpha, beta)

• Great for telling us when something happens in the brain, but

not exactly where.

• EEG is also used in sleep research — those wavy lines show

sleep stages

ERP = Event-Related Potentials

• ERPs are derived from EEG measurement of neural activity.

• An ERP measures voltage changes in the brain that follow the onset

of specific external stimuli.

• They do not necessarily require overt motor or linguistic response.

• It shows when a particular brain activity takes place (e.g., in response to event

Brain Imaging

• MRI tracks which brain areas use more oxygen during tasks.

• It’s great for mapping functions like language or vision, but

the timing is too slow to track split-second processes.

• Still, it transformed psychology into neuroscience.”

Positron Emission Tomography (PET)

• Small amounts of radioactive isotopes are placed in

the blood

• These chemical travels through the blood to the

parts of the brain that are activated during the tasks

• Different tasks show distinct activity patterns

Brain Structures and Function

• Various parts of the brain do not work

independently of each other; they communicate

with each other

• Massive parallel processing throughout the brain to

perform mental functions.

Language Processing

• Speaking a written

word involves at least

five neocortical areas

• Each area performs

certain functions

• The areas coordinate

their actions

• The brain acts as an

integrated system

Transcranial Magnetic Stimulation (TMS)

• TMS changes activity in the cerebral cortex by generating

strong magnetic pulses over the skull

David Rumelhart

developed models of learning and thinking that he described as “connectionist network models” (also known as parallel distributed processing models or PDP)

Distributed Representations

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