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.