7- Moray: COGNITIVE Flashcards
Background
Shadowing
Involves playing 2 messages to a person at the same time - 1 message is played to the right ear, and the other message is played to the left ear.
The listener is asked to pay attention to just one of the messages.
To ensure that the listener is doing this he / she has the repeat out loud the shadowed message.
Background
Cherry
Colin Cherry (1953) found that Ps had no recall of the contents of the message received by the ‘rejected’ ear, but they were aware of basic physical features, such as the gender of the speaker.
Aim(s)
Experiment 1:
To test Cherry’s original results more rigorously.
Experiment 2:
To see if some kinds of message (i.e., hearing your name) break through the attentional block to the rejected ear.
Experiment 3:
To see if expectations (set) might affect the way the message to the rejected ear is processed.
Design
(Method)
Study involved 3 lab experiments.
Experiment 1:
Repeated measures design.
Experiment 2:
Repeated measures design.
Experiment 3:
Independent measures design.
IV
(Method)
Experiment 1:
Message played to the shadowed and rejected ears (a prose passage and a list of words respectively).
There was also a control list of words not included in either message.
Experiment 2:
The effect of affective versus non-affective messages (an ‘affective’ message was one that contained the person’s name).
Experiment 3:
1) Whether digits were inserted into one or into two messages.
2) Whether Ps were told they would be asked questions about just the shadowed message or told to remember all the digits they heard.
DV
(Method)
Experiment 1:
Recall of words in the rejected message.
Experiment 2:
Number of affective instructions that were responded to.
Experiment 3:
Number of digits correctly recalled.
Sample
(Method)
Ps were male and female undergraduates or research workers.
Participants:
Experiment 1: No info.
Experiment 2: 12 Ps
Experiment 3: 14 Ps
Materials / apparatus
1) Two tape recorders (Brenell Mark IV) used to play the messages.
2) The messages to-be-played were either word lists or prose passages, read in a steady monotone.
3) The loudness of each message was approximately 60 decibels above the Ps’ threshold.
Procedure
1) Before each experiment the Ps were given 4 passages to shadow for practice, i.e., they had to repeat each passage as they heard it.
EXPERIMENT 1:
2) A passage of prose was presented to the shadowed ear and a short list of simple words was presented (35 times) to the rejected ear.
3) Recall of the rejected message was tested immediately after hearing the list using free recall (‘remember everything you can’). Within 30 seconds Ps were also given a recognition test of similar material that was not in the list nor in the prose, as a control.
EXPERIMENT 2:
4) Ps had to shadow 10 prose passages played to their right ear while, at the same time, another prose passage was played to the rejected left ear. They were told to try not to listen to the rejected ear.
5) Shadowed right ear: At the beginning of each passage there were instructions: either (1) ‘Listen to your right ear’ or (2) ‘Listen to your right ear: you will receive instructions to change ears’. This second kind of message created a ‘set’ (i.e., expectation) for further messages.
6) Rejected left ear: In the middle of 6 of the passages there were ‘interpolated’ messages played to the rejected ear. These were distributed at random. Three of these were ‘affective’ messages that contained the Ps’ name.
EXPERIMENT 3:
7) Ps were asked to shadow 1 of 2 simultaneous dichotic messages (i.e., 2 messages were played, one to each ear).
8) Digits were interpolated (i.e., inserted) towards the end of the messages. These were sometimes present in both messages, or just one message, or neither message. The position of the numbers was randomly varied.
9) Group 1 were told they would be asked questions about the shadowed content. Group 2 were told to remember all the digits they could.
Summary of different experiments
Experiment 1:
Simple shadowing task.
Experiment 2:
Affective messages.
Experiment 3:
Expectations tested.
Results
Experiment 1
1) A mean of 4.9 words (/7) from the shadowed message were recognised in the final recognition test.
2) A mean of 1.9 words (/7) from the rejected message were recognised.
3) A mean of 2.6 words (/7) from the control list were recognised.
Results
Experiment 2
4) Ps responded to more of the affective messages presented to the rejected ear than non-affective messages presented to the rejected ear.
5) 20 out of 39 affective messages were responded to compared with 4 out of 36 non-affective messages.
6) A t-test showed that this different was highly significant (p<0.01).
7) There was some effect of ‘set’ (expectations) - the mean frequency of a Ps hearing their name (affective message) when there was a pre-passage warning was 0.8 whereas it was 0.33 when there was no warning. (Not significant difference).
Results
Experiment 3
8) There was NO SIGNIFICANT DIFFERENCE between the number of digits recalled by either group of Ps, i.e., whether they had or did not have warning to remember all the digits.
Conclusion(s)
Experiment 1:
Showed that the content of the rejected message is blocked, confirming Cherry’s results.
Experiment 2:
Showed that an affective (i.e., emotional) message breaks through the attentional barrier.
Experiment 3:
Showed that neutral material does not become important enough to break through the attentional barrier even when expectations were increased by telling some Ps they had to recall all digits.
