Cog Psych Final

Cognitive psychology

scientific study of the mind and mental processes

What are the mental processes studied in cognitive psychology?

• perception

• attention

• memory

• language

• problem solving

• decision making

Donders

Used reaction time to measure the time it took to perform various mental acts. Originally an opthamologist.

What was the formula associated with Donder's experiment?

Choice Reaction Time - Simple Reaction Time = Time to make a decision

William Wundt

Field: structuralism

Contributions: introspection, basic units of experience

Studies: 1st Psychological laboratory

Ebbinghaus

created the forgetting curve and serial position effect in memory

Forgetting Curve (Ebbinghaus)

Describes how the ability of the brain to retain information decreases in time. At first it is rapid then it levels out.

William Jones

• Father of American Psychology

• mostly observation

• attention

• “My experience is what I agree to attend to…”

Did researchers dig deeper into cognition? Why or why not?

No, because Wundt's introspection labs were subjective and unreliable which caused a distrust in cognition. They instead turned to behaviorism because it was easily proven.

Behaviorism

the science of behavior that focuses on observable behavior only

Watson

Behaviorism; "Little Albert Study"; aversion therapy experiment showed how environmental manipulations affect behavior

Classical Conditioning (Pavlov)

The organism learns to associate two stimuli

One produces a response that originally was only produced by the other

Classic example of dog/bell and salivation

Operant Conditioning (Skinner)

• a method of learning that occurs through rewards and punishments for behavior

• based on consequences of actions

Tolman's Experiment

This experiment had rats run a maze and had different groups rewarded with food at different times (1st time, 2 days, 6 days) but ran the correct way every time after the reward. Proved that cognitive maps exist in rats and humans

Chomsky's Theory

Children have an inborn ability to learn language through exposure to it, not being taught it.

What do nerves do?

send and receive messages to the brain

Neurons

a nerve cell; the basic building block of the nervous system

Nerve net

a netlike control system that sends signals to and from all parts of the body

Are nerve nets continuous?

No, they consist of separate units closely lined up.

Axon

transmits signals

Cell body

power center

Dendrites

receive signals

Terminal buttons

send signals to the other neuron

Neural circuits

Groups of interconnected neurons that are responsible for specific functions of neural processing.

Why do some neural signals successfully pass through, but some don't?

Because there is a threshold for electrical signals to be detected.

Action potential

the all-or-none electrical signal that travels down a neuron's axon

What is the action potential threshold?

-70mV

A single neuron can represent a ___ ____.

unique experience

Neurons in what lobe are involved in visual and/or complex stimuli?

Temporal lobe

Do all neurons light up for all stimuli?

No, some only activate in response to complex stimuli.

hierarchical processing

processing that occurs in a progression from lower to higher areas of the brain

Specificity coding

specific neurons responding to specific stimuli

Population coding

representation of a particular object by the pattern of firing of a large number of neurons

Sparse coding

Representation by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent

What type of coding is mostly likely involved in face recognition?

sparse

How do we neurally represent complex things?

• action potential rates

• neural firings distributed across cortex

• feature detectors

• neural coding

levels of brain organization

• localized representation

• distributed representation

localized representation

specific functions are served by specific areas of the brain

distributed representation

the idea that specific cognitive functions activate many areas of the brain

neural networks

interconnected neural cells

“brain’s information highway”

Neural Network: Executive Control

controlled attention

Neural Network: Salience

survival, emotions

Neural Network: Default mode

mind wandering

Neural Network: Visual

visual perception

Neural Network: Dorsal Attention

attention to visual stimuli

Neural Network: Somato-Motor

movement, touch

Perception

experience resulting from stimulation of the senses

Are humans or machines better at interpretation based off perception?

humans because we interpret based on subjective likelihood instead of objective likelihood

Reasons machines can't perceive like humans

• objects can be blurred or hidden

• inverse projection problem

inverse projection problem

an image on the retina can be caused by an infinite number of objects

Bottom-up processing

the analysis of the smaller features to build up to a complete perception

Top-down processing

the use of preexisting knowledge to organize individual features into a unified whole

Where does perception start with Bottom-up processing?

the senses

Where does perception start in top-down processing?

the brain

4 Approaches to Principles of Perception

• Unconscious inference

• Gestalt principles

• Regularities in environment

• Bayesian inference

Unconscious inference (Helmholtz)

we make interpretations based on what is more likely to happen. knowledge informs our perception

Gestalt principle

the experience that comes from organizing bits and pieces of information into meaningful wholes according to laws of perceptual organization.

“the whole is greater than the sum of its parts”

Laws of Perceptual Organization

• good continuation

• simplicity

• similarity

Good continuation

we are more likely to perceive continuous, smooth flowing lines rather than jagged, broken lines

Simplicity

viewers tend to organize elements in the simplest way possible

Similarity

Objects that are similar in appearance are more likely to be perceived as belonging in the same group.

Physical regularities

regularly occurring physical properties of the environment

What are the physical regularities?

1) there are more vertical and horizontal in the environment

2) light usually comes from above.

Semantic regularities

knowledge of what a scene ordinarily contains make us process these things easier

Bayesian inference

The idea that our estimate of the probability of an outcome is determined by the prior probability (our initial belief) and the likelihood (the extent to which the available evidence is consistent with the outcome).

Experience-dependent plasticity

the process through which neural connections are created and reorganized throughout life as a function of an individual's experiences

Fusiform Face Area (FFA)

an area in the temporal lobe that contains many neurons that respond selectively to faces

Brain ablation

removal of part of the brain to see how it affects function

Temporal pathway

-perception pathway
- answers what
- responds to shape and color and contributes to our ability to recognize objects and faces

Parietal pathway

- action pathway
- answers where
- helps us process movement in the visual environment

mirror neurons

neurons in the brain that are activated when one observes another individual engage in an action and when one performs a similar action

The communication between two neurons occur at ....

synapse

T/F: A 8000 mV signal would trigger action potential more strongly than would a 8 mV signal.

False

Some neurons specifically respond to complex objects. Where are these neurons located?

temporal lobe

A neural representation that is characterized by use of a pattern firing of a large number of neurons is known as:

population coding

_________ are interconnected areas of the brain that can communicate with each other

Neural networks

Which of the following is an example of top-down processing?

You're reading somebody's horrific handwriting. Even though some words are impossible to read, you can predict what those words are based on the rest of the sentence.

"The whole is different than the sum of its parts" is the main argument of

Gestalt theory

The localized facial recognition are of the brain is:

FFA

Viewpoint invariance is

ability to recognize and object even when it is seen from different angles

You watch somebody dancing and some neurons in your motor cortex respond as well. This happens via

mirror neurons

Attention

the ability to focus on specific stimuli or locations

Selective attention

attending to one things while ignoring others

Divided attention

paying attention to more than one thing (multi-tasking)

attentional capture

a rapid shift of attention caused by an unusual stimulus

What type of attention leads to inattentional blindness?

selective attention

inattentional blindness

a failure to perceive objects that are not the focus of attention

Dichotic listening

a task in which people wearing headphones hear different messages presented to each ear but are told to focus on one ear specifically

What comes from dichotic listening?

cocktail party effect

Cocktail party effect

ability to attend to only one voice among many

Filter model

Model of selective attention that suggests that information from a sensory buffer is put through a filter that allows only selected inputs through (Broadbent)

Sensory memory

- - holds all incoming information for milliseconds
- sends them to "the filter"

the Filter

Identifies attended message based on physical characteristics like gender, pitch, accent, etc.

Only attended message is passed on to the next stage

The Detector

- detects the meaning of filtered message
- output sent to memory

What are the processes of the Filter Model?

- Sensory memory
- The Filter
- The Detector

Models of Attention

- Early Filter Model
- Attenuation Model
- Late Selection Model

Attenuation Model

The mind has an attenuator which is able to turn down unattended sensory input rather than eliminating it. Attended sent through attenuator at full strength while unattended are weaker.

Attenuator

analyzes incoming message in terms of physical characteristics, language, and meaning

Dictionary Unit

contains words, stored in memory, each of which has a threshold for being activated

Late Selection Model

A model of selective attention that proposes that selection of stimuli for final processing does not occur until after the information in the message has been analyzed for meaning.