moray

• background 


  Allport->multi-channel theory of divided attention - showing that two or more operations can be carried out at the same time.

  Cherry-> shadowing to test attention, messages fed into both ears must be fed back, form of dichotic listening
• aims

  1. Test cherry’s findings in relation to recognised info in rejected + hearing name
  2. /3. investigate other factors that can affect attention in dichotic listening
• sample


  undergraduates from Oxford

  1. N/A
  2. 12 p's
  3. 14 in each condition (28 total)
• method Experiment 1:


  •Repeated measures

  •IVs: (i) the dichotic listening test (ii) the recognition test

  •DV: number of words recognised correctly in the rejected message

  •A short list of words was repeatedly presented to one of their ears whilst they shadowed a prose message in their  other ear

  They were asked if same intensity in each ear
• method Experiment 2:


  •Repeated measures

  •IV: whether or not instructions were prefixed by the participants own name

  •DV: number of affective instructions
• procedure, exp2


  • P's shadowed ten short passages of light fiction in their right ear, (each being a different condition) while in their left ear another prose passage was played, they were told to ignore this (rejected ear)
  • Shadowed R ear:  instructions to either (1) listen to your right ear or (2) listen to your right ear: you will receive instructions to change ears
  • Rejected left ear: middle of six passages, "interpolated " messages played to the rejected ear. These were distributed randomly. Three were affective messages that contained their name 
• method: exp. 3


  •Independent measures

  •IVs: (i) whether digits were inserted into both messages or only one (ii) whether participants had to answer questions about the shadowed message at the end of each passage or whether they had to merely remember all the numbers they could.

  •DV: number of digits correctly reported
• procedure: experiment 3


  •Two groups of 14 Ps shadowed one of two dichotic messages.

  •In some, digits were inserted towards the end of the message. These sometimes present in one or both of the messages.

  •position of the numbers relative to each passage were varied and randomly inserted.

  •Controls with no numbers were also used.

  •One group of Ps told they would be asked questions about the shadowed message at the end

  •The other group was specifically instructed to remember all of the numbers that they could.
• materials


  •A Brenell  Mark IV stereophonic tape recorder was used.•They were modified with 2 amplifiers to give two independent outputs through attenuators – one output went to each earpiece of a pair of headphones.•Matching for loudness was approximate – participants were asked to say when 2 messages the seemed equally loud to the experimenter were subjectively equal to them.
• results: exp1


  5/7 words in shadowed message recognised

  2/7 words recognised in rejected message

  support findings by Cherry
• results: exp2


  20/39 heard instructions preceded by name

  4/39 heard instructions not preceded by name
• results exp3.


  •difference between the mean no. of digits reported under the 2 conditions were analysed and submitted to a t test (a test to compare the means of two groups).• In none of the cases (whether the score was the mean number of digits spoken during shadowing, the number reported, or the sum of these two) was the difference significant even at the 5% level of confidence.
• conclusions


  •A short list of simple words in the rejected message show no trace of being remembered even when they were presented many times. •A person will hear instructions if they have their own name in the rejected message. •In a situation where a participant directs their attention to the message in one ear, and rejects the message in the other ear, almost none of the verbal content in the rejected message can get through.