Moray

• Background: What is attention?

  • Attention is a cognitive process that enables us to select information that is constantly being bombarded at our brains and concentrate on it whilst at the same time also rejecting information  
  • This is referred to as selective or focussed attention 
  • Research has been conducted into both auditory and visual selective attention 
• Background: What did Cherry find?

  • People are very skilled at tuning in to one voice or conversation while tuning out other conversations - cocktail party effect
  • Did various investigations getting people to listen through headphones whilst two different messages played in each ear – this is known as a dichotic listening task 
  • Participants had to shadow the message out loud as listening and ignore the other message and found that little information could be remembered from unattended message 
  • This has applications in air traffic control 
• Background: Broadbent

  • First to compare processing of information by the brain to the processing of information by a computer 

  Filter model of selective attention – sensory filter mechanism that early on in processing of information, selected only one channel of incoming sensory information and blocked all others off allowing attention to be focussed  
• Background: What did Johnson & Heinz suggest?

  • Broadbent suggested selective attention happened at an early stage of processing whereas Johnson & Heinz suggested this could happen at any stage of processing information 
  • They argued that the amount of time we spend processing information that is unwanted might be affected by how easy it is to discriminate between incoming stimuli and this describes why we can switch attention if the unattended channel becomes more meaningful to us  
• What is a dichotic listening task?

  • Two different stimuli into different ears played through headphones  
• What were the aims?

  • To provide a rigorous empirical test of Cherry’s findings (experiment 1) (simple shadowing task) 
  • To see if some kinds of message (such as hearing name) break through the attentional block to the rejected ear (experiment 2) (affective cues) 
  • To see if expectations might affect the way the message to the rejected ear is processed (experiment 3) (expectation) 
• What were the controls?

  • Loudness was matched to earpieces by asking participants to say when the message appeared to be the equivalent volume to them within +1db 
  • Participants all completed 4 shadowing tasks on passages of prose before the study to practice 
  • Loudness of each message was approximately 60db above the participant hearing threshold and the speech rate was 150 words per minute 
  • All passages were recorded by one male speaker 
• What apparatus was used?

  • Brenell mark IV stereo tape recorder modified with twin amplifiers to give 2 independent outputs, one to each earpiece in the set of headphones  
• What was the method of experiment 1?

  • Lab experiment
  • Repeated measures
  • NO sample size

  IV – message played to shadowed and rejected ear

  DV – number of words recalled in the rejected message
• What was the procedure of experiment 1?

  • Read passage into shadowed ear and participants shadowed word from the passage  
  • Read short list into rejected ear (35 times) 
  • Participants asked to recall all they could hear from the rejected message 
  • Gap between test of recall was 30 seconds 
  • Recognition task consisted of similar material which wasn’t present in the passage or word list  
• What were the results of experiment 1?

  • More words were recognised in the shadowed ear than the rejected ear  

  This suggests the more we pay attention to something the more we recognise it  

  This also suggests even if something is repeated it doesn’t make it through the cognitive block 
• What was the method of experiment 2?

  • Anecdotal evidence suggests the content of the rejected message being blocked can be broken down by some kinds of material such as hearing own name 

   

  • Lab experiment  
  • Repeated measures  
  • 12 participants  

  IV – whether instructions to the rejected ear were prefixed by the participant’s own name  

  DV – number of instructions to the rejected ear that were responded to 
• What was the procedure of experiment 2?

  • Participants had to shadow 10 paired passages of light fiction 
  • Each listener received one passage in their right ear and a different passage in their left ear (10 times) 
  • They were told their responses to the shadowed ear would be recorded and should aim to make as few mistakes as possible and ignore the rejected ear 
  • In the rejected ear, in the middle of some passages there were random messages containing the participant’s own name  “John Smith you may stop now” (affective) and the next instruction contained no name (non affective) 
• What were the results of experiment 2?

  • Participants heard the instruction more if the instruction was prefixed with their name 

  This suggests the attentional block to the rejected ear can be broken down if the message means something to the individual such as their name. 

  This supports Johnson & Heinz as selective attention can happen at any stage of processing

   

  • It was noted that if participants are given a warning at the start to expect instructions to change ears there was a slight increase in the mean frequency with which they heard instructions in the rejected message 
• What was the method of experiment 3?

  • Lab experiment 
  • Independent measures 
  • 2 groups of 14 participants 

   

  IV 1 – whether digits are inserted into 1 or 2 messages 

  IV 2 – whether participants were told they would be asked questions about just the shadowed task or to remember all the digits they heard  
• What was the procedure of experiment 3?

  • Participants asked to shadow 1 or 2 simultaneous dichotic messages 
  • Digits were stuck in towards the end of the message – sometimes present in each, just one message or neither 

  Group 1 – told they would be asked questions about shadowed content  

  Group 2 – instructed to remember all the digits they could 
• What were the results of experiment 3?

  • No difference in mean scores of digits recalled correctly between the two ‘set’ conditions because numbers are not important enough to break through the block on the rejected message