Lecture 4: Divided Attention

Question 1

Explain resources associated with divided attention.

Answer 1

● Divided attention is doing 2 things at once ­ often results in loss of performance due
to divided resources. If you are highly practised at divided attention, you might do well, but without practise, there is a trade off on resources.

Question 2

Explain capacity and bottleneck theory associated with dual performance and the experiments that support it.
● Capacity theory:

Answer 2

● Capacity theory: paying attention to multiple things at once uses a shared pool of attention ­ processing is parallel and varied.
○ Wicken’s multiple resources: attention divided into perception, processing and action, with input being visual, audio, tactile and olfactory and reasoning divided into subconscious, symbolic and linguistic. Wickens asserted that sensory input/perception can come through anything and attentional resources are linked to each one of those. Thus, we should be able to do multiple things at once.
○ Neural Theory (Kinsbourne, 1981): Tasks can be performed together if the structures performing them are neurally distant. Can talk and drive, because they are separate functions, but cannot talk and write at the same time.
○ Outcome Conflict (Navon & Miller, 1987): Limitations depend on similarity of task.

Question 3

Bottleneck theory:

Answer 3

● Bottleneck theory: attend to one task and being able to rapidly switch attention to another (aka single channel theory) ­ uses serial processing.
○ Pashler’s psychological refractory period (PRP) paradigm: disagreed with Wickens, thus suggested that there are sub­parts to the whole task you’re doing. Includes: perception (peripheral), processing (central, executive function) and response (peripheral). Items get analysed through perception, then go to our central processes, then we make a response. We cannot centrally process more than one item at a time. You can shorten the Central Process to the point where it looks like you are dual processing but you always finish one first.
○ If you’re in between 2 tasks, there‘s no overlap of central processing and no delay in doing task 2. But if there is an overlap, there will be a delay in central processing of task 2.
● Other findings:
○ PRP effect reduces with practise is never disappears, tasks are always done
sequentially.
○ Training can make central processing times much shorter though.

Question 4

Explain two kinds of attention.

Answer 4

●Ribot (1890) explained two kinds of attention:
○ By volition (endogenous and voluntary)
○ By external stimuli (exogenous and involuntary)
● Posner (1980) produced a paradigm through a study where a there were a sequence
of frames, beginning with a cue showing the direction of a target (80% valid cue). Results provided evidence that attention could be pre­directed due to cues.
○ Timing of the frames of course was very important because of inhibition of return: that attention does not favour returning to planes it has already been.

Question 5

What captures attention?

Answer 5

Exogenous attention

Question 6

What is an Exogenous attention?

Answer 6

● Exogenous attention: single features that pop out to grab your attention ­ however in
this study, the problem was subjects were cued.
● Thus, what truly captures your attention is when you are not expecting anything ­ a
sudden onset, even when you’re not looking for it.
○ Does colour capture attention? No. Colour is easily ignored when told to look
for a specific letter (in this case, an ‘E’). The red ‘C’ did not distract
participants. (This goes against FIT).
○ Does sudden onset capture attention? Yes. Only stimuli which may capture
attention. House/face example shows we have both object and spatial
attention simultaneously
● This tells us that attention can be captured due to sudden onset, as it does not need
instruction. This occurs because sudden onset represents the appearance of a new perceptual object ­ new perceptual objects require creation of a new object file which is a temporary representation of objects currently in visual awareness.
○ Treisman conducted a study to test this, and found that indeed object files surely had to occur.
● Moore, Yantis + Vaughan ­ used the posner paradigm and conducted a study where 2 vertical bars flashed, where 1 clashed as a cue to show where the stimulus was expected (80% valid). They found when the cue was valid, search times were very rapid and but with invalid cues, subjects were 150 ms slower.
● Another study used face and house photos that were translucent and superimposed. Faces are analysed by the face area in the brain (FFA) and buildings activate thePPA brain area ­ when both are attended to, they activated both brain areas, but if subjects were told to focus on 1 specific part of the photo e.g. face then FFA was activated and PPA was not ­ thus attention can be selective.