moray

• broadbent (1958) suggested that the world is composed of many more sensations that can be handled by the perceptual and cognitive capabilities of the human observer -> humans selectively attend to only some information and 'tune out' the rest. -> attention is the result of a limited capacity information processing system
• cherry (1953) first used the shadowing technique as a form of dichotic listening - people presented with two or more simultaneous 'messages' and are instructed to process and respond only to one of them
• cherry (1953)

  • ppts asked to repeat 1 message out of 2 that they were listening to - messages presented at the same time and done in two ways
  • binaural task - both messages played in both ears at the same time
  • dichotic task - one message played in one ear and the other message played in the other year
  • findings - binaural task was significantly harder, dichotic task ppts could separate the messages effectively but couldn't recall the contents of the ignore/unattended message
• the cocktail party phenomenon - ability to focus one's attention to a specific stimulus whilst filtering out a range of other stimuli e.g. conversations in a cocktail party -> can focus attention on a particular conversation
• divided attention - dual-task technique where people are asked to attend and respond to both (or all) the messages -> deliberately divides people's attention
• experiment 1 aim

  test cherry's findings in relation to the amount of information recognised in the rejected message
• experiment 1 design

  laboratory experiment

  repeated measures design
• experiment 1 sample

  number of ppts not recorded

  both males and females

  all ppts were undergraduate or research workers
• experiment 1 procedure

  dichotic listening task

  attended message - a prose message that was shadowed

  rejected message - a short list of simple words repeated 35 times, played at the same time as the prose message

  IV - dichotic listening test, recognition test

  DV - ppts asked to recall all they could from the unattended message, 30 seconds later given a recognition test using similar material as a control

  3 conditions - shadowed message, rejected message and a control
• experiment 1 results

  little evidence of words from the rejected message being recognised

  mean recognition rate was lower for the shadowed message and even lower for words not present in either list

  
  

  previous appearance of words

  • shadowed message - 4.9
  • rejected message - 1.9
  • new words (neither messages) - 2.6
• experiment 2 aim

  test Cherry's findings in relation to the effect of hearing your name in the unattended message
• experiment 2 design

  laboratory experiment

  repeated measures design
• experiment 2 sample

  12 participants

  both males and females

  all ppts were undergraduate or research workers
• experiment 2 procedure

  dichotic listening task

  attended message - 10 short passages of light fiction, each being different

  rejected message - set of instructions given to the ppts, some were affective (emotional) and some were non-affective (neutral). affective instructions had the ppt's name - looked at efficiency of the attentional block

  IV - whether the instructions were prefixed by the ppts name or not

  DV - number of affective instructions that ppts heard
• experiment 2 procedure 2

  ppts told that their responses would be recorded and objective was to shadow each of the 10 passages - were told that they were scored and to try to make as few mistakes as possible

  10 passages had 2 instructions given at the same time - first was at the start of the passage, second was during the passage
• experiment 2 results

  significant differences between affective and non-affective instructions - the names caused the instructions to be heard which broke through the attentional barrier

  most ppts ignored instructions presented in the passages they were shadowing as they thought it was an attempt to distract them

  affective condition - 20 out of 39 messages were heard

  non-affective condition - 4 out of 36 messages were heard (3 results were rejected as ppts started paying attention to the rejected message)
• experiment 3 aim

  test Cherry's findings in relation to the effect of instructions to identify a specific target in the rejected message
• experiment 3 design

  laboratory experiment

  independent measures design
• experiment 3 sample

  2 x 14 ppts

  both males and females

  all ppts were undergraduate or research workers
• experiment 3 procedure

  dichotic listening task

  attended message - experimental message that was shadowed

  rejected message - either an experimental message (had digits within it) or a control message (similar message without digits)

  ppts heard

  • 2 experimental messages OR
  • 1 experimental message and 1 control message
• experiment 3 procedure 2

  IV1 - whether digits were inserted into both messages or only one

  IV2 - whether ppts had to answer questions about the shadowed message or whether ppts had to merely remember all the numbers they could

  DV - number of digits correctly reported

  all ppts shadowed an experimental message

  one group told beforehand that they would be asked questions about the content of the shadowed message

  other group told they should remember all the numbers they could
• experiment 3 results

  mean number of digits reported when ppts were told they would be asked about the content was not significantly different

  ppts could not be primed to listen for digits in the rejected message unlike the use of their own name

  stimulus not important enough
• experiment 3 overall conclusions

  In a situation where a participant directs his attention to the reception of a message from one ear, and rejects a message from the other ear, almost none of the verbal content of the rejected message is able to penetrate the block set up.

  A short list of simple words presented as the rejected message shows no trace of being remembered.

  ‘important’ messages, such as a person’s own name, can penetrate the block

  it is very difficult to make ‘neutral’ material important enough to break through the block set up in dichotic shadowing.
• research methods - strength

  laboratory experiment, possible to control extraneous variables leading to higher validity

  • ppts had the loudness in each ear individually matched to ensure differences were not caused by volume
  • messages were recorded to ensure they were spoken at a constant speed without expression
  • how loudly ppt's name was spoken was checked that it had not been stressed
• sample - strength

  students and research workers may be no different in relation to selective attention skills from the general population

  sample included both males and females - possible that there is a gender difference in selective attention
• sample - weakness

  sampling method may be non-representative as ppts were students and research workers -> cannot be generalised
• quantitative data - strengths

  allows easy comparison between conditions - digits cannot be noticed even when expected but one's name can be detected some of the time in the rejected message when not expected
• quantitative data - weakness

  no analysis of qualitative data - difficult to process detecting particular stimuli in the rejected message is unconscious -> ppts unable to say or know why they succeeded in detecting or failing to do so
• ethics - strength

  few to no ethical issues - the task, materials and findings were unlikely to cause distress

  ppts knew what was going to happen - no deception
• reliability - strength

  controlling variables such as volume, use of headphones - raised reliability and standardised procedure between ppts and conditions to allow for replication
• reliability - weakness

  some differences in ppts' experiences - some only heard and responded to the instruction to change ears so passage intended to be shadowed then became the rejected message

  • one ppt spontaneously reverted to shadowing the original ear without noticing
• validity - strength

  level of control ensured greater recall of the name than other words was due to the IV not to extraneous variables

  ecologically valid to some extent - dichotic listening represents the everyday situation of trying to follow one source of information such as conversation while trying to distract noise, chatter or dialogue
• validity - weakness

  lack of ecological validity as not realistic - rarely need to continuously listen and repeat a message
• Practical applications

  • Driver safety (Moray, 1990)
  • Directional attention to one's own name as a test of consciousness in long-term coma patients (Cheng et al, 2013)
  • Ability to switch attention between messages to understand children with listening but not hearing disorders (Dharmani et al, 2013)
• Findings suggest hearing our name can overcome the attentional blockade, but it's only partial
• Study was central to many years of research into the process to selectively attend to some inputs and the nature of stimuli that can overcome the attentional block