Week 3 Lecture B
Broadbent’s research on attention responses showed that respondents recall the numbers they
heard in an order that blends information from both left and right ear. E.g She recall a number
heard from the left ear first then a number from the right ear then a number from left ear again
and so on.
Broadbent’s filter theory
Early selection model is basically things that gets a person’s attention first gets stored in working
memory and the later information are filtered out.
Doich & Doich theory proposed that the brain processes both the left hand and right hand side
information input, and gets both stored in short term memory, however one side of information
input is more important than the other side, and that determines how much you can remember.
Further experiments supported the filter theory, however there are some limitations of the filter
model.
1. Capture of attention
2. Selection by meaning (people tend to organize the meaning of words they heard, which
supports Deutch and Deutch theory)
Rapprochement 1:
Filter only alternates processing
The threshold for processing of unattended stimuli is higher
Rapprochement 2:
Early, late it depends
High versus low perceptual load; how much other stuff is going on
High load – early selection
Low load – late selection
The fate of unattended stimuli
Early selection
-they are not remembered
- they are usually not responded to
Filter is not as inflexible as Broadbent suggested
- Important stimuli automatically capture attention and breakthrough (late selection)
Automaticity can also be seen in responding
Automatic behavior means that it occurred fast, requires zero attention, unconscious,
unavoidable/ballistic.
Psychological refractory period (PRP)
Respondent takes a long time to make a second response after a first response.
This effect meant that we cannot initiate two behaviors simultaneously.
Initiation of response is cognitively demanding than continuously performs the same action.
Week 3 Lecture A
Focused attention
Posner in the 1980s set up a computer test, trying to shift participant’s attention, with the spot
light effect, centre cue, where the attention is directed to the spot which the next cue will appear.
And there’s a peripheral cue, which is not a fixation but still can speed up your responses. There
is a peripheral, where the cue shows no connection to where the dot will appear next, in fact, it is
opposite to where the dot will appear on the screen, as a result, participants made extremely
slow responses compare to the other two cues.
There are predictive centre cues, where participants can choose where the dot will appear next,
this reduced their response time, and unpredictive centre cues where the dot might not appear
on the desired spot, and this increased their reaction time.
There’s another explanation however that our perceptual system do not limit to a spot light, in
fact the cues are processed in brain, with information of surroundings that guide your attention
around. Centre cues are endogenous or deliberate attention, and the Peripheral cue are those
exogenous or automatic attention. The question now is does centre cues work like a spot light??
The zoom lens by La Berge 1983, the reaction speed of responses are measured, the result found
shows consistent support for the theory that Centre cues works not like a spot light, but works
like a zoom lens.
In 1991, Juola, Bowhuis, Cooper & Warner experiment showed that the attention system works
neither a spot light nor a zoom in, it’s actually more complex than that, and we will be able to
focus our attention to on any area and ignoring others, but captured by peripheral cues as
demonstrated earlier. Depending on what you choose, Xenon.
Week 3 Lecture B
The cocktail party effect (Cherry, 1953) shows that there are people competing for attention,
however we can Focus our auditory attention and only hear the things we want to hear, whilst
ignoring irrelevant information. The question is do we process the other irrelevant information
and ignore it or do we just filter it out?? Broadbent’s filter theory suggested that there is an early
selection, where only the relevant information will be processed and others will be filtered out,
however Deutsch & Deutsch in 1963 proposed late selection, where all information coming in are
processed but only relevant information will be responded to.