MultitaskingDebate
Can youdo them at the same time?
A.
Talkingon the phone while driving isn't the only situation where we're worse atmultitasking than we might like to think we are. New studies have identified abottleneck in our brains that some say means we are fundamentally incapable oftrue multitasking. If experimental findings reflect real-world performance,people who think they are multitasking, are probably just underperforming inall- or at best, all but one - of their parall pursuits. Practice might improveyour performance, but you will never be as good as when focusing on one task ata time.
B.
Theproblem, according to Rene Marois, a psychologist at Vanderbilt University inNashville, Tennessee, is that there's a sticking point in the brain. Todemonstrate this, Marois
devisedan experiment to locate it Volunteers watch a screen and when a particularimage appears, a red circle, say, they have to press a key with their indexfinger. Different coloured
circlesrequire presses from dfferent fingers. Typical response time is about half asecond, and the volunteers quickly reached their peak performance. Then theylearn to listen to dfferent recordings and respond by making a specific sound.For instance, when they hear a bird chirp, they have to say "ba"; anelectronic sound should elicit a "ko", and so on. Again,no problem. A normal person can do that in about half a second, with almostno effort.
C.
The troublecomes when Marois shows the volunteers an image, and then almost immediatelyplays them a sound. Now they'e flummoxed." If you show an image and play asound at the same time, one task is postponed," he says. In fact, if thesecond task is introduced within the half. second or so it takes to process andreact to the first, it will simply be delayed until the first one is done. Thelargest dual task delays occur when the two tasks are presented simultaneously;delays progressively shorten as the interval between presenting the taskslengthens.
D.
Thereare at least three points where we seem to get stuck, says Marois. The first isin simply identifying what we're looking at. This can take a few tenths of asecond, during
whichtime we are not able to see and recognize the second item. This limitation isknown as the "attentional blink*: experiments have shown that if you'rewatching out for a particular
eventand a second one shows up unexpectedly any time within this crucial window ofconcentration, it may register in your visual cortex but you will be unable toact upon it.
Interestingly,if you don't expect the first event, you have no trouble responding to thesecond. What exactly causes the attentional blink is still a matter for debate.
E.
A secondlimitation is in our short-term visual memory. It's estimated that we can keeptrack of about four items at a time, fewer if they are complex. This capacityshortage is
thoughtto explain, in part, our astonishing inability to detect even huge changes inscenes that are otherwise identical, so-called "change blindness".Show people pairs of near-
identicalphotos - say, aircraft engines in one picture have disappeared in the other -and they will fail to spot the dfferences. Here again, though, there is disagreementabout what
theessential limiting factor really is. Does it come down to a dearth of storagecapacity, or is it about how much attention a viewer is paying?
F.
A thirdlimitation is that choosing a response to a stimulus - braking when you see a childin the road, for instance, or replying when your mother tells you over thephone that she' s
thinkingof leaving your dad - also takes brainpower. Selecting a response to one ofthese things will delay by some tenths of a second your ability to respond tothe other. This is
alledthe "response selection bottleneck theory, first proposed in 1952.
G.
ButDavid Meyer, a psychologist at the University of Michigan, Ann Arbor, don't buythe bottleneck idea. He thinks dual-task interference is just evidence of astrategy used by the
brain toprioritise multiple activities. Meyer is known as something of an optimist byhis peers. He has witten papers with titles like "Virtually perfect time-sharing in dual-task
performance:Uncorking the central cognitive bottleneck. His experiments have shown thatwith enough practice - at least 2000 tries - some people can execute two taskssimultaneously as competently as if they were doing them one after the other.He suggests that there is a central cognitive processor that coordinates allthis and, what's more, he thinks it uses discretion sometimes it chooses todelay one task while completing another.
H.
Maroisagrees that practice can sometimes erase interference effects. He has foundthat with just 1 hour of practice each day for two weeks, volunteers show ahuge improvement
atmanaging both his tasks at once. Where he disagrees with Meyer is in what thebrain is doing to achieve this. Marois speculates that practice might give usthe chance to find less
congestedcircuits to execute a task - rather like finding trusty back streets to avoidheavy traffic on main roads - effectively making our response to the tasksubconscious. After all,
thereare plenty of examples of subconscious multitasking that most of us routinely manage:walking and talking, eating and reading, watching TV and folding the laundry.
I.
Itprobably comes as no surprise that, generally speaking, we get worse atmultitasking as we age. According to Art Kramer at the University of llinois atUrbana- Champaign, who
studieshow ageing affects our cognitive abilities, we speak in our 20s. Though thedecline precipitous. In one study, he and his colleagues had both young and oldparticipants do a
simulateddriving task while carrying on a conversation. He found that while youngdrivers tended to miss background changes, older drivers failed to noticethings that were highly
14-18为匹配题
14. Atheory explained delay happens when selecting one reaction F
15.Different age group responds to important things differently I
16.Conflicts happened when visual and audio element emerge simultaneously C
17. Anexperiment designed to demonstrates the critical part of the brain formultitasking B
18. Aviewpoint favours the optimistic side of multitasking performance G
19-21为选择题
19.Which one is correct about the experiment conducted by Ren6 Marois?
Aparticipants performed poorly on the listening task solely
B.volunteers press a different key on different colour
C.participants need to use different fingers on the different coloured object
D. theydid a better job on Mixed image and sound information
20.Which statement is correct about the first limitation of Marois's experiment?
A.attentional blink" takes about ten seconds
B. lagoccurs if we concentrate on one object while the second one appears
C. wealways have trouble in reaching the second one
D. thefirst limitation can be avoided by certain measure
21.Which one is NOT correct about Meyer's experiments and statements?
A. justafter failure in several attempts can people execute dual-task
B.Practice can overcome dual-task interference
C. Meyerholds a diferent opinion on Marois's theory
D. anexisting processor decides whether to delay another task or not
22-26为判断题
22. Thelonger gap between the two presenting tasks means a shorter delay toward thesecond one.YES
23.Incapable human memory cause people to sometimes miss the differences whenpresented with two similar images. YES
24.Marois has a different opinion on the claim that training removes thebottleneck effect. NO
25. ArtKramer proved there is a correlation between multitasking performance andgenders. NOT GIVEN
26. Theauthor doesn't believe that the effect of practice could bring any variation NO