Cognitive Psychology Lecture 1: Introduction James Matthews and John Toner.
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Transcript of Cognitive Psychology Lecture 1: Introduction James Matthews and John Toner.
Course Layout
Topics to be covered:• Memory• Attention• Mental Imagery• Language• Problem Solving & Expertise• Reasoning, Decision Making & Judgements• Consciousness• Knowledge
Course Completion
• Christmas ExamFormat to follow.
• Class presentationEach student will have to give one 10 minute presentation over the course of the 12 weeks based on a set article.
Course Completion
Class presentation– Short: 10 mins, 10 - 15 slides
– Everyone expected to read the article over the course of the week
– Presentation should simply summarise the main methods (where relevant) and arguments of the article
– Presentation should finish with a ‘points for discussion’ slide bringing in their own thoughts and facilitating debate
Reading (Library: GEN/SLC 153.4)
Core text:Eysenck, M., & Keane, M. (2005). Cognitive Psychology: A student’s handbook (5th ed.) Hove, East Sussex: Psychology Press
Other sources:Reisberg, D. (2006) Cognition: Exploring the Science of the Mind (3rd ed.) New York: W.W. Norton & Company
Sternberg, R. (2003). Cognitive Psychology (3rd ed.) Fort Worth, Texas: Harcourt Brace
Cognition
The word cognition is derived from the Latin word cognoscere, meaning “to know” or “to come to know”.
Cognition is therefore the activities and processes concerned with the acquisition, storage, retrieval and processing of knowledge.
What is Cognitive Psychology?
It is the scientific study of how the mind works
“...cognitive psychology deals with how people perceive, learn, remember, and think about information.”— Sternberg (1999)
“Cognitive psychology [is] the study of processes underlying mental events”
— Solso (2005)
What do cognitive psychologists study?
Memory Decision Making
Attention Perception
Learning Neurobiology
Cognitive Development Concept Formation
Emotion Artificial Intelligence
Language Problem Solving
Mental Imagery Animal Cognition
Things which cognitive psychologists may seek to explain. . .
Why do we find it difficult to describe how to tie a shoelace without moving our hands or looking at our shoes?
Things which cognitive psychologists may seek to explain. . .
What processes are involved in planning a novel route through familiar terrain.
(e.g. How do I get from UCD to town via Dundrum)
Things which cognitive psychologists may seek to explain. . .
How can we recognise a song from its first few beats?
Things which cognitive psychologists may seek to explain. . .
Phenomena like that shown in this video
http://gigglesugar.com/349186
Approaches to Cognitive Psychology
• Experimental Cognitive Psychology
• Computational Cognitive Science
• Cognitive Neuropsychology
• Cognitive Neuroscience
Experimental Cognitive Psychology
Tightly controlled experiments carried out under laboratory conditions on healthy individuals.
Experiments often designed to disrupt cognitive processes and thus reveal their workings.
(e.g. Distracting participants attention)
Findings lead to theories, which in turn lead to testable claims
(e.g. “Instrumental music does not disrupt reading”)
Experimental Cognitive Psychology
Sample Experiment: Effect of arousal level on reaction time.
Reaction time assessed on a machine where buttons light up and time to respond is measured
Arousal assessed through heart rate measurement
Conditions: 1) After rest2) After cognitive load3) After exercise4) After caffeine5) After exercise and caffeine
Experimental Cognitive Psychology
Some limitations:• Is behaviour in a laboratory fundamentally different
to that in real world settings. Are the findings of experiments ecologically valid?
• Does not look directly at brain function, but rather the explicit behavioural results of brain function. Thus we may miss something.
• Tendency to negate individual differences by averaging many participants’ performances. Does not allow for the possibility of unique cog. function
Computational Cognitive Science
Computational modelling involves recreating some aspect of human cognition in the form of computer program, flow chart or formula in order to predict behaviour in novel situations
Computational Cognitive Science
Computational models can vary in complexity from relatively simple flow charts to highly detailed connectionist networks.
In these latter models units or nodes are connected to many others.
In a particular scenario units take the weighted sum of the inputs coming to it and produce a single output to another unit.
Networks can be arranged in complex layered systems
Computational Cognitive Science
Some limitations• There are usually many ways to model a particular
cognitive phenomenon• There is a lack of a definite method for relating a
computational model’s behaviour to human behaviour
• It is extremely difficult, if not impossible, to take every cognitive factor into account when creating a model (e.g. Do models of language processing take into account the emotional connotations of particular sentences for particular individuals?)
Cognitive Neuropsychology
Concerned with the cognitive functioning of those who have suffered brain damage
• Damage to region X disrupts ability Y• People who have lost ability Y also have problems
with ability Z
From studying people with brain injuries we make assertions about healthy brain function
Cognitive Neuropsychology
Sample Case: Frontal Lobe damage• People with frontal lobe damage often show little
cognitive deficit when given IQ tests• However they have extreme difficulty with things
like–Socially acceptable behaviours–Cognitive flexibility–Abstract thinking
• Frontal lobes are the area which differ to the greatest extent between human and ape brains
Cognitive Neuropsychology
Some limitations:• Ethically we cannot cause brain damage in
humans so we have to work with what we find. This damage is rarely ‘clean’
• Interpretation of findings in relation to those suffering damage to several areas is very difficult
• If ability Y is disrupted by damage to region X, it does not tell us what role X has in Y. Is it the functional centre, or simply a vital stage? There are 50 billion interconnected neurons.
• What was cog. functioning before injury?
Cognitive Neuroscience
Using brain imaging and brain anatomy to study ‘live’ cognitive functioning in healthy individuals
As the technology improves, these studies are becoming more influential and potentially useful
Methods include: (Details to follow!)• Single Unit Recording• Event Related Potentials (ERPs)• Positron Emission Tomography (PET)• (Functional) Magnetic Resonance Imaging (fMRI, MRI)• Magneto-encephalography (MEG)• Transcranial magnetic stimulation (TMS)
Cognitive Neuroscience
Some Limitations• Techniques are of questionable use with high-order
functioning which might not be organised in a concise way
• If data from several individuals is averaged the interpretations become accordingly blunt
• Tendency for research to be conducted for the sake of research. Papers can often be lacking any theoretical basis, and result in ad hoc hypotheses
• Threshold levels need to be set to disregard noise. These levels are a contentious issue!
Cognitive Neuroscience
Event Related Potentials (ERPs)• Electrical brain activity (EEG) is measured on the scalp• Several readings for the same stimuli are averaged to
counteract spontaneous background activity
Cognitive Neuroscience
Event Related Potentials (ERPs)
Pros:
Best detail of the timeline of cognitive events
Cons:Only useful with simple, low-level stimuliSkull and scalp distort emerging electrical waves
Cognitive Neuroscience
Positron Emission Tomography (PET)• Radioactive substance injected into the body and observed
as it gathers in blood vessels of brain• Activity levels are determined as (very mild) radioactivity
levels are measured by subtracting activity levels at rest from activity levels during a particular task
Cognitive Neuroscience
Positron Emission Tomography (PET)
Pros:
Maps wide range of cognitive activities including complex tasks
Reasonable location of active areas (3-4 millimeters)
Cons:Scans indicate total amount of activity over 60 seconds. Not sensitive to rapid changes in activity
How closely are changes in distribution of radioactive water related to neural activity?
Cognitive Neuroscience
Functional Magnetic Resonance Imaging (fMRI)• Radio waves produce neural activity picked up by a large
magnet. • If used to scan anatomy of brain for tumors etc. it is MRI. If
used during tasks to detect brain function it is fMRI.
Cognitive Neuroscience
Functional Magnetic Resonance Imaging (fMRI)
Pros:
No biological risks
Provides anatomical and functional information
Cons:Poor temporal resolution of a few seconds
How closely are changes in oxygenated haemoglobin related to neural activity?
Some experimental techniques
Eyetracking• Infrared cameras can detect where the eye is
looking and for how long• Used to study reading
Some experimental techniques
Eyetracking
Analysis of advertising, phobias, expert search patterns etc
Stimulus Presentation Software
Experiments may require a computerised stimulus presentation of stimuli in order to create ideal conditions and accurately measure responses
QuickTime™ and aH.263 decompressor
are needed to see this picture.