PSY 200 MSU Exam 1

Cognitive Psychology

The study of the mind, the study of mental processes

Mental Processes

-Perception

-Attention

-Memory

-Language

-Deciding

-Reasoning

-Judgement

Machine Learning Attacks against the Asirra CAPTCHA

Computer attempt to recognize cats.

Humans- 83.4% correct in one try

Machine- 10.3% correct in one try

Perspectives on the mind

Behavior --> The mind

Brain -->The Mind

Behavior

-Main focus of cognitive psychology

-Expression of the mind

Brain

-Main focus of cognitive neuroscience

-Physical basis of the mind

History of cognitive psychology

-Physics begain in the 1600 with Galilei and newton in the 1600s

-Modern Chemistry began in the 1700 with Boyle and Lavoiser

-Beginning of cognitive psychology is somewhere in the 1800s.

-It is a young field because no one knew where to begin

Early work

innovations and debate on whether and how to even measure mental processes

Introspection

1st attempt to measure the mind.

-It is a way of measuring the mind.

Wilhelm Wundt (1832-1920)

Analytic introspection

-Systematic

-Highly trained observers

Periodic Table of the Mind

Finds the basic sensations (atoms) from which experiences are built

William James (1842- 1910)

Based on his own insights on introspection

-His method of introspection was to use himself. It was how he thought of thing; he was the experimental subject.

-Deep thinker; not systematic

Problems with introspection

-Hard to get reproducible results

-Variability

-List of basic sensations did not agree

-Not objective <-- Psychology struggles with objectivity

Common Characteristics (early more objective approaches)

They link a mental process to a physical ( measurable) property

Franciscus Donders (1818-1889)

How long (physical property) does it take to make a decision (mental process)

1st Condition Ex. "Whether a spot is on the left or the right"

2nd condition ex. "Dot on the left, knock"

Donders Reasoning

-Response time to be minus response time to a: how long it takes to make this decision

-We are discussing this because he is an early researcher aiming to objectively measure mental processes.

Hermann Ebbinghaus (1815-1909)

How fast do memories fade?

- He measured how long it took to memorize all sequences in a list...then waited a while...Then measured how long it took to re-learn them.

-used himself as an experiment subject

-We are discussing him because he is an early researcher aiming to objectively measure mental processes

-Physical= change in savings over time

-mental= memory

Ernest Weber (1795-1878)

Gustav Fechner (1801-1887)

Quantifying perception

-Said the larger the quantity (e.g weight, size), the larger the change in that quantity needs to be to be noticed

-Mental= Perception

-Physical= Quantity (length

Weber Fechner Law

Still a well known law in psychology

Experimental Science

Where the mind appeared to be moving to

Behaviorism (The reason for the gap)

-The mind is not observable, only behavior is. According to this, the mind is irrelevant.( Input--> Output relationship)

-Researchers inferred about the mind but directly observed only behavior

-Defined as the study of the relation between the behavior and the environment

Behaviorists

Push cognitive science back out of experimental science

Pavlov's Dogs

Important inspiration for behaviorism

-classical conditioning pairs with a neutral and non neutral stimulus

John Watson's Little Albert Experiment

The idea that humans are shaped by their input

Behaviorist discard introspetion

introspection is only concerned with the mind

Behaviorism led to a great increase in the understanding of types of learning

-skinner box

-classical conditioning stimulus

-

B.F Skinner

Operant conditioning (pigeon in a skinner box)

Operant conditioning

pairs a behavior with a non-neutral stimulus

-change in frequency of that behavior

a stimulus that increases the frequency associated with behavior

true (reinforcer)

1950s/1960s

Behaviorist period ended; behaviorism becomes less popular

Operant condititoning can also involve pleasant stimuli, leading to increase of particular behavior

false (no need to say pleasant or unpleasant)

Noam Chomski

Reason 1. Argues that language is not learned through conditioning. (linguistics)

Behaviorism is less popular

Reason 2: Computers more widespread. They led to new ways of conceptualizing the mind.

An information- processing device

The minds connection with computers

Saul Sternberg

Responsible with the rebirth of cognitive psychology.

almost any cognitive psychology experiment involves what?

A model

1967

First EVER textbook on cognitive psychology

Together, behavior and brain will alow better understanding than either alone

True

All the experiments we have viewed so far

All behavioral measures

Perception

1st. Chemical process

2nd. Neurons activated

3rd. Brain structures activated

4th. Groups of brain structures activated

Mostly ignored in this course

Chemical processes

Main function of this course

Perception

Basic unit of the brain

The neuron (nerve cell)

Neurons

-Complex activity of the brain takes place here. Meant to pass on information from one place to the next.

-Represent information

Information about facial expressions reach the brain by

(from the eye into the brain)

neurons

Dendrite

the end that receives signals (input)

Axon (nerve fiber)

The end that passes the signals on (output)

Neurons are joined together by _______, forming networks

synapses

The gap that separates neurons is called the

synapse

How can neurons contain the information conveyed by the face?

They contain information conveyed by

A neuron might contribute to representing

-A certain object that you see

- A sound you hear

-A memory you recall

-A thought you have

-etc

Axons of ___ layer of neurons meets dendrites of the _____ layer

First, Second

Information of the brain travels as..

1. An electric signals

2. A chemical signal from one neuron to the next

At rest( no signal being transmitted)

Inside of a neuron has negative electrical charge relative to the outside.

What cell is a very elongated, hollow tube?

Neuron

Where does the electrical charge come from?

Charged ions that float outside and inside the neuron.

At rest

More positively charged ions outside of the neurons than inside

This imbalance is responsible for the electrical charge, inside negative relative to outside

Resting potential

membrane

outside wall of membrane

Ions cant simply pass through

Resting imbalance

What happens when signal travels along axon?

Negative potential briefly turns positive

Nerve Impulse

Brief change in potential, traveling along neuron

Causes nerve impulse

Change in membrane.

The role of ion channels

Allow ions to pass through

Ion Channels

Big molecules embedded in membrane

Ion channels can be opened or closed

True

Nerve impulses can not only be seen, but also heard

True

Arrival of the nerve impulse along axon..

leads to the release of neurotransmitter molecules

Excitatory Neurotransmitter

Increase chances of post- synaptic nerve impules

Inhibitory Neurotransmitters

Decrease probability of nerve impulse after synapse

Signal transmitter along neuron is

electrical

signal transmission between neurons

Psychoactive drugs take effect in the synapse

True

They resemble neurotransmitters and either __________ their effect

mimic or block

when a neuron fires impulses more often

it has a message to convey

Change in potential for each impulse ALWAYS

remains the same

All thoughts, feelings, memories, perceptions, etc are conveyed by _______

Nerve impulses

Higher rate of nerve impulses means?

More intense signal

Nerve impulses can be measured directly using..

(ticks from speaker, spikes on screen)

Neural Representation Example

Visual Perception

Retina Cells

Tells the brain what is in front of the persons eyes

What does a retina cell represent?

-The level of light falling onto its location in the retina

OR

-The level of light coming from the corresponding location in the visual field.

OR

-More light: receptor gives stronger signal

Retinal Ganglion Cells

Represent a visual neurons receptive field:

-Region of space in which light levels influence the neurons firing

Receptive Field

Region of space that a neurons firing conveys information about

Response in receptive field

Less

Stronger signal from retinal receptor results in stronger signal in ganglion cell (in the middle)

On center, off surround

True

Stronger signal from retinal receptor results in weaker signal in ganglion cell in (Outside of the center)

Center Surround Organization

Off Center, On surround

Negative center, positive on the outside

Retinal Ganglion Cell Represents

Difference in light level between center of its receptive field and the edges of its receptive field

Center Surround Organization (balanced)

Important for detecting edges/contours.

Cells Response: Weak/absent

Center Surround Organization (not balanced/towards the edge)

Cells Response: Strong

Retina

Where retinal ganglion cells are

Primary Visual Cortex (Towards the back)

Where visual information 1st enters the cerebral cortex.

Pulls info from whole row of ganglion cells

David Hubel

Torsten Wiesel (1950s/1960s)

Put their electrodes in the primary visual cortex of cats

Retinal Receptors

-Must be at a particular location and have a particular orientation on the cell

Horizontal Light

No neuron response

Tuning curve

Orientation of the bar relative to the rate of spikes

Neurons in the primary visual cortex represent

Orientation of any contour in its receptive field

other visual neurons represent even more abstract aspects

-the direction of motion of an image moving through the receptive field

-the presence of a face, car, bird, etc in the receptive field (different neurons respond to different objects

Non-visual neurons also represent what?

aspects of the animals (humans) cognitive state