Cognitive Psychology What is “Memory”? The process of storing and retrieving information. What is “Cognitive” Psychology? It’s about how our mind deals with information, and our abilities to use that information. Why is Memory Important? Life Without Memory: The Case of Clive Wearing, Part 1a - YouTube Life Without Memory: The Case of Clive Wearing, Part 1b - YouTube
Cognitive Psychology What is “Memory”? The process of storing and retrieving information. What is “Cognitive” Psychology? It’s about how our mind deals with information, and our abilities to use that information. Topic: MODELS OF MEMORY 1. The Multi-Store Model (Atkinson & Shiffrin, ‘68)
What’s a “model”? • Not an exact copy, but a representation of something • Helps us understand how something works
Sensory Memory Encoding
Sensory Memory Capacity & Duration
Testing Iconic SM • The next slide demonstrates your iconic sensory memory at work! • Keep your eyes fixed on the slide and concentrate!!
How many letters can you recall? • This was based on an experiment by Sperling (1960): • Presented a grid of letters for less than a second • People recalled on average 4 letters • Although, when Sperling used “partial report” technique… • …showed that iconic memory held up to 10 items! • But decays before we can report them all • Duration: • Info decays within about 2 secs (or less)
Short Term Memory Encoding & Capacity Click Here to Continue
Activity 1 - Encoding in STM • You will need a pen/pencil and paper. • When you go to the next page, you will be presented with a sequence of letters, which will appear in the centre of the screen one after another. • Try to memorise the letters in sequence as they are presented. • ONLY when you see the word NOW appear, write the letters down in the same order as they were presented.
B V E G D C P T NOW
How many did you get? - answers below. • B D T G C P E V • Remember, to count as correct, the letters must be in the correct sequence. • Now try it again!!
W A F M L Q R Z NOW
Howdid you do this time? - answers below • W L F Z M Q R A • If you did better, this fits in with previous findings… • Conrad(1964) first did this experiment • Visually presented students with letters one at a time • Found that: letters which are acoustically similar (rhyming) are harder to recall from STM than those which are acoustically dissimilar (non-rhyming) • This suggests that STM mainly encodes things acoustically (as sounds), even though the items were presented visually.
Activity 2: Capacity of STM • As before, you will need a pen/pencil and a piece of scrap paper. • When you go to the next page, you will be presented with a sequence of numbers, which will appear in the centre of the screen at one second intervals. • Try to memorise the numbers in sequence as they are presented, but DO NOT WRITE ANYTHING DOWN. • When you see the word “NOW” appear, write the numbers down in the same order as they were presented (serial recall)
4 3 6 8 9 2 1 5 7 NOW
How did you do? - see below • 5 7 4 8 3 1 9 6 2 • Miller(1956): the STM can hold ‘the magic number seven, plus or minus two’ • On average, the capacity of STM is between 5 and 9 items of information.
Activity 3: Extending STM Capacity • When you go to the next page, you will be presented with a line of letters across the screen. • Memorise as many of the letters as you can but do not write anything until the word NOW appears. • When you see the word NOW appear on the screen, write down on your paper as many of the letters as you can remember, in the same order as they were presented.
Could you remember more this time? • Now try it again!!
You probably did better this time - Answers below. GCE BTEC GCSE GNVQ ASWhy might this be? – (apart from having seen the stimulus material twice, an example of the practice effect). • Miller (56) found that the capacity of STM could be considerably increased by combining/organising separate ‘bits’ of information, e.g. letters or digits, into larger chunks. • Chunking involves making the info more meaningful, through organising it in line with existing knowledge from your LTM - in this case, of abbreviations for qualifications.
Short Term Memory Duration
How long can you retain a new phone number before you have to write it down? …if you didn’t rehearse it? • The duration for which STM can retain info is temporary – a very short time • Not much research interest of this aspect, but… • …some findings suggest only a few secondsbefore it fades/decays (unless we rehearse it)
Activity: duration of STM • This next experiment was first carried out by married couple Peterson & Peterson (1959) • Got students to recall combinations of 3 letters (trigrams), after longer and longer intervals. • During the intervals, students were prevented from rehearsing by a counting task! • On the next screen, you will see a trigram for a few seconds. • A 3-digit number will then appear in its place. When this happens, start counting backwards in 3’s from the number until you are told to stop. • Pens down….ready?
303 V J P
X G A 419
K Z Y 297
After 18secs, fewer than 10% recalled correctly. • Their findings suggest that our STM fades in under a half a minute if we are not rehearsing it: After only 3secs, 80% recalled correctly. Recall got progressively worse as the delay grew longer!
The Long Term Memory Encoding
Activity: encoding in LTM • Try to memorise them in order, and wait for the word “NOW!” before you write…
SNOOZE KIP SNORE REST NAP DOZE SLUMBER SLEEP YAWN DREAM NOW!
Now write down as many as you can remember. You should have done ok, as you were using your STM • Based on Baddeley(1966) • Presented lists of 10 short words one at a time • Some lists were semantically similar, others not • Tested immediately & then after 20 min delay • Found that after 20 mins, they did poorly on the semantically similar words • This suggests that we encode LTMs according to what they mean – so we get similar-meaning things confused! • Encoding in LTM is “semantic” – meaning-based
The Long Term Memory Capacity & Duration
Easy! • Capacity = potentially unlimited. • Duration = anything up to a lifetime. (minutes to years) • Difficult to test exact duration, but… • Bahrick et al. (1975) tested US graduates • Shown classmate photos years later • 90% accuracy for remembering faces & names 34yrs after graduation • Declined after 48yrs, particularly for faces
Iconic Processes Sense Decay Short Store Seven Unlimited Rehearsed Semantic Organs Sensory Structure Seconds (x2) Lifetime Attention Duration Long Acoustic Summary – Fill in the blanks!
Key Features of the MSM “CAPACITY”: how much info this store can retain • 3 different types of memory • Model describes these as “memory stores” • SM, STM, & LTM • Any stimulus you come across has been in one or more of these stores – in this sequence! • Each store retains a different amount of info, in a different way, and for a different length of time “DURATION”: how long this store can retain info for “ENCODING”: the form in which the memory is retained
“ECHOIC MEMORY”: auditory input from the ears – things you HEAR. Stored as sounds. • The SM takes info from one of the sense organs and holds it in that same form “ICONIC MEMORY”: visual info from the eyes –things you SEE. Stored as images. “HAPTIC MEMORY”: tactile input from the body – things you’ve TOUCHED. Stored as feelings.
For us to remember a piece of info well, we need to: • Pay attention to it • This gets it from the SM to the STM • Rehearse it • Maintenance rehearsalkeeps it in our STM • Elaborative rehearsalcan get it to our LTM
Check you can… • Describe the key features of the model • Describe encoding, capacity, and duration, AND evidence relating to: • SM • STM • LTM • Explain strengths & weaknesses of the model
Evaluation of the Model Evidence Strengths & Weaknesses of the evidence Flaws Alternatives
Glanzer & Cunitz (1966) Read out list of words to Ps Asked them to recall as many as poss. Findings: recalled more from start and end of list Supports the idea of there being a separate STM & LTM, because… Experimental Evidence
The “serial position effect”:(Glanzer & Cunitz, ’66) “PRIMACY EFFECT”: these words were the first heard- they’ve been rehearsed, so we can recall them from our LTM “RECENCY EFFECT”: these words are the most recently heard - so we can recall them as they’re still in our STM
Case Study Evidence • Several cases of patients who have suffered brain damage to their hippocampus & have memory deficits: • H.M. • Clive Wearing • K.F • Their memory loss tends to be selective • This again supports the idea of separate stores for different types of memory
Brain Scanning Research “REMEMBER NEW INFORMATION” – the hippocampus is active during this task, which requires your LTM • MRI scans show which parts of the brain are being used when certain tasks are carried out: “MAKE A DECISION” - the prefrontal lobes are active now, when using your STM • These findings back up the existence of different stores for different memories
First comprehensive model Generated a wealth of research. Strengths
Simplistic in several ways STM = 1 store? Unlikely LTM can be divided too: Semantic, procedural, episodic Verbal rehearsal only? Oversimplified. STM and LTN rely on each other Weaknesses