Memory
A Memory Experiment
• Shortly, you will be shown a series of items.
• Watch carefully, as you will be asked to recall as many of them as you
can at the end of the presentation.
• You can write which items you remember on a piece of paper, but
should not write anything as you go along.
• When you come to recall the items, you can write them down in any
order that you want.
• Remember to watch carefully!
• When you are ready, the presentation will begin…
End of
Presentation
• What can you
• remember?
• People tend to remember the first few items in a
list.
• This is known as the primacy effect.
• People tend to remember the last few items in a
list.
• This is known as the recency effect.
• People tend not to remember the items that occur
in the middle of a list.
• These findings are also described as the serial
position effect. In other words, the serial position
of an item in a list (e.g. whether its 1st, 2nd, 3rd,
last, etc) affects the chance of it being
remembered.
A graph to demonstrate the serial position
effect
recency effect
primacy effect
25
% recall
20
15
10
5
0
serial position of items
Question: Why does the primacy
effect happen?
Answer: Because the first few items are ________
and _______ to ____ _____ memory. This means
they are _______ for recall at the end of the
presentation.
Question: Why does the primacy
effect happen?
Answer: Because the first few items are rehearsed
and transfer to long term memory. This means
they are available for recall at the end of the
presentation.
Question: Why does the recency
effect happen?
Answer: Because the last few items are still in
_____ ____ memory and have not yet _______.
This is why people often to remember them first,
otherwise they will be lost.
Question: Why does the recency
effect happen?
Answer: Because the last few items are still in
short term memory and have not yet decayed.
This is why people often to remember them first,
otherwise they will be lost.
Question: Why are items in the
middle of a list often forgotten?
Answer:
• Because people are busy rehearsing the first few items
they cannot give enough _________ to the middle items.
• Because by the time people reach the end of the list the
middle items have _______.
• Because the middle items have also been __________ by
the later items that have come into ______ _____
memory.
Question: Why are items in the
middle of a list often forgotten?
Answer:
• Because people are busy rehearsing the first few items
they cannot give enough attention to the middle items.
• Because by the time people reach the end of the list the
middle items have decayed.
• Because the middle items have also been displaced by the
later items that have come into short term memory.
Question: What would happen if you were shown a series of
items but were not allowed to recall them straight away?
Instead, you had to count backwards for 30 seconds
(a distracter task).
Answer:
• You would tend to remember the first few items still because they get
rehearsed into long term memory.
• However, the ‘distracter’ task would stop you from recalling items from
short term memory. You would ‘lose’ the recency effect.
• The task would probably displace any items left in the STM. Even if it
didn’t, all items should have decayed by the end of the task.
Core Study
In Memory
Terry (2005)
“Serial Position Effects in
Recall of Television
Commercials”
Aim
Terry’s aim was to show that the serial position effect occurs
when people are presented with a series of television
commercials.
Hypothesis
• (i) He predicted that if he showed participants a
block of television commercials then, on average,
the earlier and later ones would recalled more
than the middle ones.
• (ii) He also predicted that if he delayed recall of
the commercials, only the earlier ones would be
recalled well.
Method
• Terry used an experiment, with a repeated
measures design. Participants were shown a block
of commercials in both conditions.
• In Condition 1, they were asked to recall the
products they had seen (in any order they wanted)
immediately after presentation.
• In Condition 2, they were asked to recall the
products they had seen (in any order they
wanted)after a delay of 3 mins (where they did a
written task).
Method
• There were 15 commercials in a
block.
• All commercials were 15 or 30
seconds in length.
• Commercials were 10 months old
on average.
• Commercials were presented in a
different order depending on
participant.
Results
immediate recall
Recall
delayed recall
Serial Position of Television Commercial
Results
• As the graph shows, when participants were able
to recall the television commercials immediately
there was a primacy effect and a recency effect.
• However, when participants’ recall was delayed
there was a primacy effect but no recency effect.
Conclusion
The first few commercials were well remembered in
both conditions because participants had the time
and capacity to rehearse them, and store them in
long term memory.
Conclusion
• The last few commercials were remembered well
in the ‘immediate’ condition because they were
still held in short-term memory.
• The last few items were remembered poorly in the
‘delayed’ condition because they had been
displaced by the distracter task and/or had
decayed over the duration of the task.
Evaluation
• The experiment took place in a laboratory using an
artificial task…
so findings may lack ecological validity.
• The experiment only measured memory through recall of
television commercials…
so had low construct validity.
• Participants may have deduced the aim of the study…
and responded to demand characteristics.