Slides Week 8 Flashcards
Cognitive Psychology
- The branch of psychology concerned with the scientific study of the mind
Three concepts of the mind
- The mind controls and creates mental functions:
ie: perception, attention, memory emotions, languiage, deciding and thinking - The mind is a system that creates representations of the world so that we can act within it to acheive our goals
- Mind’s operation must be inferred from what we can measure of behaviour or physiological responses
Cognition
The mental processes such as perception, attention and memory that are what the mind does
Early Studies of the Mind
- Donders (1868) was interested in how long it takes for a person to make a decision
- Found that processes with more mental processes tended to have longer reaction times
- Simple Reaction Time was the time it takes to make a decision
- Choice Reaction Times were 1/10th second longer than Simple Reaction Time
Analytic Introspection
- Method used my Wundt (1879) to study the mind
- Developed Structuralism
- Technique where researchers train their participants to examine their thought process or their experience in response to a provided stimuli.
- An experimental example could be to ask participants to stand outside in the rain for a short period of time and then describe it
William James (1890) - Principles of Psychology
- Considered topics such as cognition, thinking, consciousness, attention, memory, perception, imagination & reasoning
A History of studying the mind - Behaviourism
- Behaviourism central tenet was that psychology should only study observable behaviour
- It held that invisible mental processes were not valid topics for the study of psychology
How does cognitive psychology talk about the Mind?
- Sees Information Processing as a way to study the mind
- Makes analogy the the mind is like a digital computer
- Operation of the mind occurs in stages
- Input
- Input Processor
- Memory Unit
- Arithmetic Unit
- Output
Models play an essential role in Cognitive Psychology
- Models play an essential role by representing structures or processes
- Structural models - Represent structures in the brain and how they are connected
- Process Models - Illustrates how a process operates
Structure Models
- Represent structures in the brain and how they are connected
Process Model
Illutrates how a process operates
Attention
The ability to focus on specific stimuli or locations in our environments
Selective Attention
- The ability to focus on one message while ignoring all others
- Selective attention has been demonstrated using dichotic listening procedure (Cherry, 1953)
Distraction
One stimulus interfering with the processing of another
Divided Attention
Paying attention to more than one thing at a time
Attentional Capture
A rapid shifting of attention usually caused by a stimulus such as a loud noise, bright light or a sudden movement
Dichotic Listening
- Presenting different stimuli to the left and right ears
- Participant “shadows one message to ensure he is attending to that message
- Participants could not report the content of the message in the unattended ear
The Cocktail Party Effect
The ability to selectively attend to a single stimulus when input is crowded.
Sensory Memory
- Holds all incoming information for a fraction of a second and then transfers all information to the next stage
Early Selection Model -
Broadbents Filter Model
- Sensory Memory
- Filter
- Detector
- Short-Term Memory
Filter
- Identifies attended message basod on physical characteristics and only attended message is passed on to the next stage
Detector
Processes all information to determine higher level characteristics of the message
Short Term Memory
- Receives output from Detector
- Holds information for 10-15 seconds and may transfer it to long term memory
Evidence against Broadbents Filter Model
- Dear Aunt Jane experiment
- Gray & Wedderburn (1960)
- Participants incorporate information from both streams if it makes more sense
Attenuation Model of Selective Attention
- Triesman’s (1964) Model - The Leaky Filter Model
- Messages
- Attenuator
- Attended Message
- Unattended Messages
- Dictionary Unit
- To Memory
Attenuator
Mechanism that analyses incoming message in terms of physical characteristics, language and meaning
Dictionary Unit
- Contains words
- Each word has a threshold for being activated
Evidence against the Leaky Filter Model
- Mackay (1973)
- Participants were asked the meaning of a sentence.
- They heard ambiguous sentences and heard a biasing word in the other
- Meaning of biased word affected participants choice despite not being aware of the biasing word
- Moray (1969)
- Paired electric shock with words
- Participants showed stress response when these words were presented to the unattended ear
Late Selection Models
- Deutsch &Deutsch (1963, 1967)
- Proposed that selection doesn’t occur until messages are processed enough to determine their meaning.
- All stimuli is fully analysed
- Most important/relevant stimulus determines the response
*
Attention: Capacity
Load Theory of Attention (Lavie, 1995,2000)
- How do people ignore distactions when they are trying to focus their attention on a task?
- Processing Capacity
- Perceptual Load
- Distraction is less likely for high load tasks because no capacity remains to process distracting stimuli
- Hard tasks result in longer reaction times than easy tasks
Load Theory of Attention:
Processing Capacity
How much information a person can handle at any given moment
Load Theory of Attention:
Perceptual Load
The difficulty of a given task
Attention: Selection
Attention can be used to select between things we are interested in processing
Overt Attention
- Shifting Attention by making eye movements
- Strong link between eye movements, attention and perception
Stimulus Salience
- Areas that stand out and capture attention
- Bottom up determinants of eye movement
Scene Schema
- Knowledge about what is contained in typical scenes
- Attention is being affected by knowledge of what is usually found in the scene
- Eye movements are determined by a task
- Top-Down Determinants of eye movements
Covert Attention
- Shifting attention without making eye movements
- Visual attention can be directed to different places in a scene even without eye movements
Attentional Spotlight - Posner (1980)
- Do we direct our attention to locations or to objects
- Everything within a small region of the viusal field can be seen clearly, but it is much harder to see anything not falling within the attentional spotlight beam.
Attention to a Location
- Participants respond faster to a light at an expected location than at an unexpected location
- This happens even when eyes are kept fixed
Criticism of Location Based Attention
- Attention can be allocated to one of two figures that occupy the same spatial location
Attention to an Object
Same Object Advantage
- Egly et al., 1994
- Participants saw two side-by-side rectangles followed by a target cue
- Reaction time fastest when target appeared where cued
- Reaction time was faster when the trget appeared in the same rectangle
- Enhancing effect of attention spreads throughout the object.
Can we direct our Attention to Locations and Objects
- Ther is no conclusive evidence one way or the other
BUT
- Mozer & Sitton (1998)
- Object based selection operates either before or at the same time as location base selection
Why not both Spatial AND Object Location instead of one over the other
Divided Attention
- Schneider and Shiffrin (1977)
- Practice enables people to do things that were difficult at the same time
- Divide attention between remembering target and monitoring rapidly presented stimuli
- Task can become automatic with practice
- Automatic processing occurs without intention and only uses some of the person’s cognitive resources
- BUT this was only true for simple tasks
- When tasks difficulty increased Automaticity decreased
Divided Attention
100 Car Naturalistic Driving Study
- Video recorders placed in 100 cars
- Recorded 82 crashes and 771 near crashes in 2,000,000 miles of driving
- 82% of crashes and 67% near crashes driver was inattentive in the 3 seconds prior
- Accident risk is 4x higher when using a cell phone
Inattentional Blindness
- Stimulus that is not attended to is not perceived
- This happens even if a person is not looking directly at it.
Change Blindness
- If shown two versions of a picture differences are not immediatley apparent
- When shown photos they say they “would” have detected the change
- More likely to notice change if participant relates in some way
- Suggests in group/out group bias
Binding
- Process by which features such as colour, form, motion and location combine to create perception of an object
- Attention when experiencing a coherent world
- Allows integration of different information that relates to the one stimulus
Treisman’s Feature Integration Theory
- Object
- Preattentive Stage
- Analyse into feature
- Focused Attention Stage
- Combine Features
- Perception
- Preattentive Stage is automatic, requires no effort or attention, people are unaware of the process
Treisman and Schmidt (1982) Experiment
- Participants report combination of features from different stimuli
- These are called Illusory Conjunctions
- Illusory Conjunctions occur because features are free floating
- In focused attention stage, attention plays key role and features are combined
Illusory Conjuction
- The psychological effect when participants combine features of two objects into one object.
- Attention acts as a perceptual glue
- Treisman and Schmidt (1982)
- Participants can correctly pair shapes and colors when they are told to ignore black numbers and focus on objects
Balint’s Syndrome
- Have an inability to focus attention on individual objects
- Patient RM had a high number of illusory conjunctions
Attention Binding - Visual Search
Where participants look for an object amon a number of distractor objects
Attention Binding: Feature Search
You are looking for a single feature amongst objects
Attention Binding: Conjunction Search
You are looking for a combination of two or more features
