Cognitive Psychology- Lectures 1-4 Flashcards
Multi-store Model of Memory: Atkinson & Shiffrin (1968). Limits.
Over-simplified – suggests that both the short-term and long-term stores are unitary
Assumes the short-term store is a gateway to the long-term, so that information has not had any contact with information in long-term memory
But, chunking is done through making meaningful groups. Meaning can only be added from long-term memory
States that the short-term store is the contents of consciousness – meaning that unconsciously
processed information should not make it to long-term memory
Assumes all items in short-term memory are of equal status
Assumes most information in long-term memory gets there through rehearsal
Working Memory Model
Baddely & Hitch (1974) argued STM should not be thought of merely as a holding pen for a small set of information chunks
They asked what short-term memory is for
Working memory refers to a brain and cognitive system that allows both temporary storage and manipulation of information, necessary for a variety of complex cognitive tasks
Dual-Task Rationale for the Working Memory Model (WMM)
A key feature of WMM is that it permits the performance of more than one cognitive task at a time, provided each task is processed by a different subsystem.
Evidence comes from dual-task experiments (e.g. Logie, Zucco & Baddeley, 1990) in which people are asked to do two things at the same time.
Working Memory Model
The Phonological Loop: Consists of two parts, a phonological store that holds acoustic or speech-based information for about 2 seconds, and an articulatory control process that produces our “inner speech”. The articulatory control process allows us to sub-vocally rehearse information to ourselves to keep it refreshed in the phonological store.
The Visuospatial Sketchpad: A subsystem that allows us to maintain and manipulate visual and spatial images. Consists of visual cache (stores input about visual form and colour) and inner scribe (deals with spatial and movement information).
The Central Executive: The control centre that coordinates subsystems, allows us to select among possible actions, strategically allocates attention to different subsystems.
The Episodic buffer: temporary storage system that can hold and integrate information from the phonological loop, visuo-spatial sketchpad, and LTM. It is controlled by the central executive.
Craik and Lockhart (1972): Levels of Processing:
The level or depth of stimulus processing has a large effect on its memorability
Deeper levels of analysis produce more elaborate, longer lasting and stronger memory traces than shallow levels
Craik and Tulving (1975):
Incidental learning – participants performed tasks involving a number of words, but were not aware that their memory for these words would be tested. Task conditions differed in terms of level of processing:
Shallow graphemic: participants decided whether a word is in uppercase or lowercase letters
Intermediate phonemic: participants decided whether each word rhymes with a target word
Deep semantic: participant decides whether each word fits the blank in a sentence
Perceptual Processing (Shallow Processing) - processing of material to extract superficial sensory characteristics (e.g., shape, colour etc.). Leads to poor retention.
Semantic Processing - processing of material to extract meaning. Leads to better retention.
Long-Term Memory
Distinctiveness:
The more distinctive a piece of information is, the more likely it is to be remembered
Relevance:
An individual is more likely to remember information related to something they know a lot about/something related to them
Emotionality
Emotional stimuli are automatically processed more deeply than neutral
Emotional stimuli activate the amygdala, which in turn activates brain regions up and down the processing pathway (LeDoux, 2000)
Greater processing of negative or threat related information has a clear evolutionary advantage, as it would allow for better avoidance of dangerous situations
This greater processing leads to greater memory for emotionally valenced (especially negative) information
Tripartite Division of Memory Processes
Encoding - Process of transforming any information into a coded representation.
Storage - Process of storing the encoded representation in the memory
Retrieval - Process of retrieving the stored representation and reconstructing the event
Memory processes: Encoding
Encoding – the processing of information for storage.
Two major encoding processes:
Organisation
Organisable information remembered better than unorganisable information
Power of instructions & incidental learning
Mnemonics help memory because they provide retrieval cues that enable one to access the information wanted:
Method of loci – walking through the rooms of a ‘memory theatre’
Reduction mnemonics – reduce the information to a set of retrieval cues e.g.
red,orange,yellow,green,blue,indigoandviolet.
Elaboration mnemonics – associate each item you want to remember to a line of a rhyme that you know
Memory processes: Retrieval
Retrieval cues – tags attached to the memory which facilitate its recovery.
Tulving & Pearlstone, 1966 distinguished between the availability of a memory (it is in there somewhere) and its accessibility (it can or can’t be accessed on this occasion).
Retrieval cues make available memories accessible
Context as a retrieval cue, where context can refer to
Environment
Tulving’s (1983) Encoding Specificity Principle
“Recall will be maximised when the context at recall matches the context at encoding”
Physically reinstating the context
Mental reinstatement
Godden & Baddeley (1975)
Deep-sea divers learned word lists on beach and under water
Later recalled the words in either same or different learning environment
Divers tested in a different environment recalled 40% less than those tested in the same environment
Context as a retrieval cue, where context can refer to:
Internal state: e.g. Goodwin et al. (1969): information learned while drunk is best remembered while drunk
Mood: information learned when happy is best remembered when happy
Have we forgotten anything?
Forgetting:
Forgetting function: a mathematical formulation of the rate of successful retrieval as a function of time:
The items used in the experiment should not have been in memory ever before.
Decay - memories fade or deteriorate over time.
Interference – learning of new or old information can disrupt or prevent retrieval so memories encoded in long-term memory (LTM) are forgotten and cannot be retrieved into short-term memory (STM).
Two types of interference:
Retroactive Inhibition: recent learning interfere old memories.Retention was better over a period of sleep than over the same amount of time devoted to activity (Jenkins and Dallenbach, 1924).During sleep participants were not exposed to new material that could interfere with their memories (McGeoch, 1942).
Proactive Inhibition: old information prevents the recall of newer information. For example, when trying to recall a new phone number, the old phone number you have previously had could make itdifficult to remember the new number.
Sensory Stores:
Sensory stores (or registers) are limited to one sensory modality, and hold information very briefly
Iconic Memory: Visual sensory store
Echoic Memory: Auditory sensory store
Movement from Sensory registers to short-term memory relies on Attention
If attention is not given to the stimulus, the sensory trace will quickly decay
Remember – attention can be overt and covert
Short-Term Memory:
Very limited capacity
Shown by digit/letter/word span tasks
Typical number of items that can be retrieved is 7 (±2) (Miller, 1956)
If items can be meaningfully grouped together into chunks, more can be remembered
the information is held in the short-term store for much longer through rehearsing.
For auditory information the coding is phonological
Items need to be rehearsed in order to move to long-term memory
Items can be lost from short-term memory through displacement
New items can ‘push out’ older items
Long-Term Memory:
No known limit on capacity
Coding is semantic
Forgetting happens slowly
Support for the Multi-Store Model
Support for short-term and long-term memory comes from studies of brain-damaged patients
Look for a double dissociation
Double Dissociation: Some people perform well on task A but poorly on task B, other perform poorly on task A but well on task B
Amnesic patient HM had impaired LTM but intact STM (Corkin, 1984)
KF had impaired STM but intact LTM (Shallice & Warrington, 1970)
If memory is unitary (one process or store) this should not occur
What is attention?
Attention acts as a means of allocating limited mental resources to information and cognitive processes at a given moment.
The brain chooses from among the various stimuli that strike the senses at any given moment.
allows only some info to enter into consciousness
Alertness and arousal:
The basic aspects of attention that enable a person to extract information from the environment or to select a particular response (full alertness)
Vigilance
(sustained attention) – the ability to sustain alertness (monitor an event or stimulus) continuously
Selective attention
ability to scan events/stimuli and pick out the ones that are relevant (difficult to monitor two events in the same modality)
Divided attention
payingattentionto two or more tasks.
Dichotic listening
METHOD
Two voices, each speaking a different passage presented to the left and right ear
RESULTS : Subjects are able to accurately report the content of the attended channel, but very little of the unattended channel, and most subjects are only accurate on reporting whether the voice was of a woman or a man.
The Cocktail party
Selective Attention: you can’t attend to all conversations at once
Divisible Attention: you can converse while getting a drink at the same time
Voluntary Attention Shift: you can consciously shift your attention from one conversation to another
Involuntary Attention Shift: you suddenly hear your name being spoken by some people across the room
Filter Models of Attention
Filter theories of attention try to explain why attention is selective
Attention is directly linked to perception
Many models of perception see perception as some kind of process from raw data to interpreted information.
E.g. vision: raw retinal image -> edges/blobs -> shapes -> objects
Filter theories of attention postulate that there are certain ‘filters’ along this informational pathway that only makes certain information pass, but not other.
Where along the pathway are these filters?
Gray & Wedderburn’s Study (1960)
Participants heard a mixture of numbers and words presented to each ear, such as, “Dear – 7 – Jane” in the left ear and, “9 – Aunt – 6” in the right ear and were asked to report back what they heard.
They could successfully shadow a message that jumps back and forth between ears.
This means that people can shadow based on meaning, not just physical characteristics.
Von Wright, Anderson, and Stenman (1975)
Processing with no awareness : When a word previously associated with electric shock was presented in the non-attended channel, participants sometimes showed a galvanic skin response.
This is an example for processing of unattended words.
Ann Treisman’s model (1960)
Selective attention involves three stages:
Parallel pre-attentive analysis of the physical properties of the stimulus;
Analysis of stimuli patterns (e.g., is it speech, music, etc?). A stimulus that meets the target pattern gets passed on to the next stage. If it doesn’t then only a weak version of it is passed on;
Attention is focused on the stimuli that make it to this stage. This includes sequential evaluation of the incoming messages, and the assignment of meaning.
Deutsch & Deutsch’s Late Selection Model (1963)
All information, both attended and unattended, undergo analysis for meaning.
After such analysis, selection of a sensory input takes place.
A major effect on selecting the input is the relevance of the information during the time of processing.
Focused visual attention
Attentional shifts from one target to another can be achieved:
Overtly: overt movement of head and/or eyes (saccades)
Covertly: internal shift, in conditions where there is no time for head or eye movements.
Divided attention
Focused attention asks about the extent to which we can focus on one task and ignore others.
Divided attention asks about the extent to which we can do more than one task at the same time.
Strategic control: the degree to which attention can be allocated, relatively, to competing tasks is under strategic control (Wickens and Gopher, 1977)
Clinical Attention Deficits
Neglect syndrome: the lack of attention to one side of space, usually the left, as a result of parietal damage
That inability is not due to a lack of sensation
Sensory-Representational Component of Neglect - Internal Representations
Left-neglect patients show right side bias in their descriptions of memories
Patient describing Piazza del Duomo
The mental ‘spotlight’ fails to illuminate left-sided features whatever the viewing perspective is.
Defining Sensation and Perception
Sensation
The detection of physical energy emitted or reflected by physical objects.
It occurs when energy in the external environment or the body stimulates receptors in the sense organs.
Perception
The process by which the brain organizes and interprets sensory information.
Measuring Senses
Absolute threshold: the smallest quantity of physical energy that can be reliably detected by an observer.
Absolute Sensory Thresholds
Vision:
A single candle flame from 30 miles on a dark, clear night
Audition (Hearing):
The tick of a mechanical watch from 20 feet in total quiet
Olfaction (Smell):
1 drop of perfume in a 6-room apartment
Touch:
The wing of a bee on your cheek, dropped from 1 cm
Taste:
1 tsp. Sugar in 2 gal. water
Kinaesthesia – the ability to know the position of your body even when your eyes are closed
Visual Perception
the ability to interpret the surrounding environment using light in the visible spectrum reflected by objects.
The resultingperceptionis also known asvisual perception, eyesight, sight, orvision.
Roughly 40% of cerebral cortex is involved in vision.
Eye Functions
Light is reflected from objects in the environment enters the eye through the pupil and is focused by the cornea and lens to form sharp images of the objects on the retina. The network of neurons that covers the back of the eye and that contains the receptors for vision (photoreceptors)
Based on feedback from the visual system, the lens of the eye adjusts its thickness to focus light on the photoreceptive cells of the retina, also known as the rods and cones, which detect the light and respond by producing neural impulses.
Receptors in the Human Eye
There are two types of photoreceptors in the human retina,rodsandcones.
Optic Nerves
Left : the optic nerve contains about 1 million optic nerve fibers.
Right: a) Which area in the retina causes firing in a single optic nerve fiber? This area is called receptive field of that optic fiber.
b) Overlapping receptive fields of three optic nerve fibers.
LGN cells have center-surround receptive field organization. Only 10% of inputs to LGN come from the retina. LGN function is believed to regulate neural information as it flow from retina to cortex. LGN receives more feedback from the cortex than it receives information from the eye.
Processing
Bottom-up processing: Here the perception begins with the stimulus itself. The processing is carried out in one direction from the retina to the visual cortex, with each successive stage in the visual pathway carrying out ever more complex analysis of the input.
Top-down processingrefers to the use of contextual information that is being used. For example, identifying the dog was easier when you knew what to look for.
Size constancy
Our perceptions of the size of objects are relatively constant despite the fact that the size of object’s image on the retina varies greatly.
The retinal size of an object image depends both on its size and on its distance from the observer.
Gesalt Theory
Law of similarity: similar things tend to appear grouped together.
Law of Pragnanz (conciseness): objects are seen in a way that makes them appear as simple as possible
Law of proximity: things that are near each other seem to be grouped together.
Law of continuity: points along straight or curved lines are seen in a way that follows the smoothest path.
Law of closure: things are grouped together if they seem to complete some entity.
Law of Common Region: elements that are located within the same closed region tend to be grouped together.
Audition
the sense of hearing
Sound – physical phenomenon caused by vibration of material
These vibrations trigger pressure wave fluctuations in the air
Wave forms
Sound propagation
Particles oscillate back and forth about they do not propagate with the wave.
Physical Dimensions of Sound
Amplitude - height of a cycle relates to loudness Measured in dB (Decibels) 0 dB is hearing threshold
Wavelength (λ)
- distance between peaks
Frequency (f )
- cycles per second (1 Hz = 1 cycle per second)
relates to pitch
humans are sensitive to a frequency range of 20-20,000Hz
Psychological Dimensions
Loudness (wave amplitude)
higher amplitude results in louder sounds
measured in decibels (db), 0 db represents hearing threshold
Pitch (wave frequency)
higher frequencies perceived as higher pitch
hear sounds in 20 Hz to 20,000 Hz range
Audition- The Ear
Outer ear
consists of the pinna, or auricle, and theearcanal
Middle Ear
chamber between eardrum and cochlea containing three tiny bones called the ossicles (hammer, anvil, stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window
Inner Ear
innermost part of the ear, containing the cochlea, semicurcular canals, and vestibular sacs
Cochlea
coiled, bony, fluid-filled tube in the inner ear
Tonotopic coding
Pressure waves distort basilar membrane on the way to the round window of tympanic duct:
Location of maximum distortion varies with
frequency of sound
Frequency information translates into information about position along basilar membrane
Solving Problems
Thinking;
Reasoning
Decision Making
Judgements
Analogies
Using a description of a similar problem and solution to solve the one at hand
Classic example – Duncker (1945) Gick & Holyoak (1980) – the Radiation Problem
Analogies are not always easy to spot, other factors play a role
Visual or text-based information
Animation for static imagery (Kubricht et al, 2015)
Crucially, more information might be needed (i.e. an indication of the strength of the radiation beam)
Definition of Problem Solving
Definition – The process of finding a solution to a complex issue.
Can vary in complexity and type
Crosswords/Anagrams/Sudoku
Chess, Fifa, Call of Duty, Plants vs Zombies
Finding a location, making friends, dating, identifying a career path, navigating through a crowd
Problems are either Well or Ill Defined
Well defined problems are when we know all or most of what we need to know to solve it
Ill-defined problems are when we don’t know much about how to solve it, or perhaps the goal is not clear
Can be adversarial or not.
Behavioural view (e.g. Hull, 1920)
Remember the general approach of behaviourists focus on Response – Reinforcement to shape behaviour
For problem solving then behaviourists argue for reproductive strategies and/or trial and error approaches
Gestalt Approach – problem solving is a productive strategy using insight
Wolfgang & Kohler (1927) – Ape called Sultan seemingly having a “Eureka!” moment when trying to solve a the suspended banana problem
Banana suspended from the ceiling, objects lying around that might help.
Behaviourists would argue that Sultan simply learned a complex series of behaviours
Gestaltists argue that there is an obvious moment where Sultan knows the solution
The General Problem Solver (GPS) – Newell & Simon (1958/1961)
Most influential and complete model of problem solving – for humans and machines
Means-end analysis – breaking the problem down
Problem solving takes place over a series of states
1) Initial state – statement of the initial problem
2) Intermediate states (goal states) – multiple possible moves on the path to solution
3) End state – problem solved!
Heuristic (general) and algorithm (specific) rules play a role
Judgements
Drawing a conclusion from a combination of knowledge and observation
Knowledge component tends to be the key in theories of judgement
Base Rate information – the information we know about a topic
So Base Rate information, or in other words, knowledge/experience is important
Utility
Expected Utility Theory states that you would make your decision according to the formula:
Value x Probability of winning for each option
Heuristics and Bias
Availability heuristic – memory for a similar previous event(s) to the one at hand that can easily be recalled (e.g. “words beginning with a specific letter…)”
Representative heuristic – general idea about a task or a group of people (stereotypes)
Affect heuristic – making choices that are influenced by emotions (positive emotions = decisions viewed as higher in benefits;negative = focus on the possible downsides
Gamblers Fallacy
The gamblers fallacy occurs when we believe that a specific result is “due”
However, this has no effect on the likelihood of it occurring – all the possible outcome are equally likely on each individual spin
Sunk Cost Effect
Throwing Good Money after Bad
For example, continuing to spend money on repairing an old car when it would be cheaper to buy a new one - the part at fault right now is cheaper than buying a new car, but in the long run all the small repairs add up to more
Other Factors that affect Decision Making
Framing (how a decision is “framed” or worded)
Can be positive or negative (or neutral)
E.g. Lives lost versus lives saved
Reference dependence or “Status quo bias”
i.e. the state before the decision is made
Loss Aversion
“Losses loom larger than gains”
Reference Dependence
Sometimes called status-quo bias
Refers to how we interpret outcomes relative to a baseline
For example, if we find or lose money we see this as money gained or lost and not in terms of our net worth
Deductive Reasoning
Deducing conclusions from a set of given premises
Research typically focuses on logical reasoning, using syllogisms
Inductive Reasoning
Use of logical processes that are probable rather than certain to arrive at a conclusion
Inductive Reasoning underpins several factors involved with thinking.
Concept Learning
Associative Learning
Hypothesis Testing
Concept Learning
Concepts are mental representations, in multiple forms of classes of an object
Concepts can be natural or logical
Logical – Defined by rules or specific characteristics e.g. shapes
Natural - less strict in how they use rules and stem from direct experience/observation
Concept formation can be explicit or implicit
Explicit – There is an underlying concept is clear (e.g. a triangle has three sides)
Psycholinguistics
Sub-field of cognitive science devoted to the study of language
“The study of the mental mechanisms that make it possible for people to use language” (Garnham, 1985)
Focus on comprehension rather than production
Psycholinguistics continued
Parsing: how we understand sentences
Semantic interpretation: what it means
Mental models: how text is cognitively represented
Pragmatic interpretation: how it fits with broader understanding
Evidence largely from experiments and computer modelling
McClelland & Rumelhart (1981): computational model
We identify letters according to their basic elements
Word Superiority Effect: context is the best guide
Linguistics: the work of Noam Chomsky
Syntactic Structures (1955) “revolutionised the scientific study of language”
Challenged the behaviourist view that language is mostly learned/modelled
Later evidence from children’s mistakes
Universal grammar
Innate potential for language learning
Specific grammar rules constrain possible sentences in any particular language
‘Unconscious knowledge’, rapidly acquired in childhood
Deep vs surface structure
How meaning and grammar are independent
Deep structure: the topic of the sentence (meaning)
Surface structure: how it’s expressed (form)
Same deep structure, different surface structure
Same surface structure, different deep structure
Syntax
How the sentence is constructed
Any sentence needs to follow (specific) grammar rules, irrespective of meaning
These don’t change much over time
Semantics and pragmatics
Usually overrides syntax – clues from context
‘Colourless green ideas sleep furiously’ (Chomsky, 1955): grammatically plausible nonsense
‘The bachelor is happily married’ – contradiction
Pragmatics: choice of words/order
Certain considerations: relevance, concision, truthfulness
Other rules apply, e.g. conversation
Lexical access:
information needed to retrieve a word from the lexicon
Perceptual (spelling)
Contextual (meaning)
Parsing
Assigning sentence elements to grammatical classes
Difficult unless clauses are marked
Doubly self-embedded sentences
