Attention Articles Continued

Attentional Limitations in Doing Two Tasks at Once:

• Why is multitasking becoming more important?
• Computers, etc. our life is much more quick than it used to be, and there are lots of things trying to grab our attention.
• People think they can multitask, but most really can't. This is another example of a failure of meta cognition.
• Central Bottleneck: central processing that can only handle so much info and limits your attention.
• This article may suggest that you just get better at the task so you don't have to give as much attention to it.
• Working memory (also like a bottleneck) - maybe it is closely related to attention... that is, how much can we keep in our working memory?
• Maybe there is hope for multitasking if we can modify the task to be easier as well as train people for the tasks.
• Perhaps this is a biological issue - otherwise we wouldn't be able to function if we attended to everything around us.
• To measure, you could use accuracy or response time. The authors of this article argue for response time.
• Response time is good because your speed in doing something may be more effected than your accuracy.
• P.R.P - Psychological Refractory Period : This is when the Reaction Time 2 is longer with the short time between stimuli (SOA). In other words, central processing gets delayed because it is still working on the first task.
• Stimulus Onset Asynchrony (SOA) - Time between two tasks.
• So maybe we are never truly doing two things at once, maybe we are just good at figuring out when to split/shift the focus of our central processing.
• If there is a long enough delay, perhaps the bottleneck is avoided (with a long time between the two tasks, a long SOA).
• ex. cars on a one way bridge - a jam is not noticeable with more time/space between each car.
• So, what other tests can show the presence of a central bottleneck?
• A longer reaction time for task 1 should correlate with a longer reaction time for task 2. (trial by trial).
• If these things happened in parallel, then we could sometimes finish the 2nd one first, but since that never happens, it may be that there is a bottleneck.
• They suggest a strategy of making Task 2 easier/shorter, to see if it could be completed before Task 1.
• If you make task 1 easy, it is hard to demonstrate that no central processing is needed for task 1. You wouldn't have a very straightforward interpretation of the data.
• If you make the 2nd task easy, on the other hand, it shouldn't require a psychological refractory period if it doesn't need central processing.
• latent bottleneck: response time 1 is so short that it may finish before a 2nd task even begins.
• If you eliminate PRP, perhaps there is no bottleneck..?
• If you make task 2 very easy, you could make it so central processing for task 1 wasn't necessary, but you might use it anyway, and task 1 would hog it from task 2.
• 3 Strategies where passing the bottleneck might have worked:
• ideomotor compatibility: stimulus resembles sensory feedback from the response (ex. saying a word as it appears on the screen).
• practice: may help, but these studies were measuring accuracy, not reaction time. They may still have a delay in processing. But there are also cases where practice seems to have eliminated PRP totally.
• Special Response Systems: tings like eye movements may not require any central processing, so there may not be a bottleneck.
• A response where the person doesn't have tot hink about at all may be the key for eliminating bottlenecks. 
• In all cases, eliminations that worked were when the easy task is task 2, not task 1. 
• Implications: processing is non-recurring, so you may encounter things that are very new and you can't practice them, so probably things like cellphones and riving will never really go hand in hand.
• So, how far can multitasking go?
• not very far, most studies have shown bottlenecks. It is unlikely we can sidestep bottlenecks all together.

Neural Basis of Selective Attention:

• Contextual modulation: the neurons that are responsible for our visual perception are active in a different way when we're attending to something than when we are not (i.e. occipital lobe for vision).
• The reaction of the occipital lobe is modulated (changed) in different contexts. It is more active when you are attending to a stimuli.
• There are parts of the brain that modulate, and there are parts of the brain that focus attention for those parts.
• some stimuli may not be represented in the brain if they are not being attended to (this may disagree with the other articles...)
• Bottom-up attention: Stimulus driven; salience (most noticeable or important) External
• Top-down attention: voluntary; intentions or goals (this is more where the article focuses). Internal
• Toward what can attention be directed?
• Visual space : spatially focused attention modulates neural activity in the extra striate cortex.
• motion-based attention : area MT (for motion) is activated bt motion. attention can indeed be motion selective.
• Object-based attention: different areas that are specific to objects are activated during different attending. (such as the face area or the house area during the face/house exercise).
• What areas of the brain produce signals to attend or not?
• Frontal eye field: may be linked to planning to move your eyes somewhere. (FEF)
• Superior Parietal lobe
• intraparietal sulcus
• Topographic maps: areas of space correspond to areas in the brain.
• Is the attentional area also topographically organized? We don't know yet.

Attentional Blink

• What is the attentional blink and under what conditions does it occur?
• when a person is doing two tasks, you catch the first one very well, but the second task you fail at. It usually takes about .5 seconds to recover. (but not when the stimuli are back to back, just when they have some space between them.)
• The classic explanation of this phenomena is that there is a resource drainage going on (that is, we have a limited capacity to process information). The authors of this article disagree.
• The author here says there is actually a temporary enhancement.
• They claim that it is only when you have distractors in-between the stimuli that you have an attentional blink.
• The author says the blink may just be because the other experiments are being done with distractors in-between.
• this leads to reactive suppression - that is, exposure to one kind of thing takes away from elsewhere. Without distractors, there is no blink, and that is exactly what they found.
• The tasks done in labs are kind of unusual, so it may not apply to something like driving in the real world. He says that it is a useful mechanism though, because it helps focus your attention on one thing.

Emotional attention:

• perception may lead to emotion, but emotion may also effect what we perceive.
• Perhaps this means emotion interacts with attention networks or mechanisms. In fact, maybe they interact in the same way, or maybe they are the same system?
• Emotions may be able to enhance some perception or diminish others.
• We respond faster to emotional stimuli (negative ones, such as snakes), but positive emotions may also have an enhancing effect.
• Positive stimuli tend to broaden our attention, where as negative stimuli helps us narrow our attention to the one thing.
• Is attention enhancing certain areas of the brain?
• Emotions act a bit like attention - yes. If a face has a strong emotion on it, such as anger, the Fusiform Face Area is activated more. So yes, emotions do act like attention on the neural level of stimulation.
• So, are they really the some thing? Do emotion and attention act through the same systems as other stimuli?
• This can be answered with an example of someone with neglect syndrome. Would they respond to emotional stimuli in the neglected area?
• They do indeed attended to emotional things in that hemisphere, so the emotional attention is not exactly the same thing as attention. They operate partially independently, but they do seem to interact.

Attention, Distraction, and Cognitive Control Under Load:

• The fundamental question: Does attention act to enhance the perception of some stimuli at the expense of other stimuli? Or are all stimuli that reach our system always perceived, whether or not they are attended to?
• Its hard to know which is right. Attention may be a process of filtering out irrelevant information (early selection), or maybe the stimuli are processed completely, but are sorter through mentally later (late selection).
• This article argues that both early and late selection work together under different circumstances.
• Summary of main ideas:
• high perceptual load: demanding perceptual task: we may be so engrossed with a current task that other stimuli truly aren't processed.
• high cognitive load: here, distractors may be perceived, so when/how much of an effect do they have? Your reflexive processes are here (distractors). They may have greater interference in high cognitive load tasks.
• more competitive under a low load, as well as in attentional capture ex. judging line lengths is high load, so you are less likely to process the distractor.
• We do less well in attentional tasks when we have a heavy distractors load.
• higher perceptual load helps, (better at early selection), but high cognitive load decreases (worse at late selection. They are opposites).
• distractors may effect brain processing.
• inattentional bias.