BRAIN DIVIDES TO CONQUER: Although the human brain cannot actually do two things at the same time, a new study shows how it can keep two separate goals in focus at once.
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The human brain is considered to be pretty quick, but it lacks many of qualities of a super-efficient computer. For instance, we have trouble switching between tasks and cannot seem to actually do more than one thing at a time. So despite the increasing options—and demands—to multitask, our brains seem to have trouble keeping tabs on many activities at once.
A new study, however, illustrates how the brain can simultaneously keep track of two separate goals, even while it is busy performing a task related to one of the aims, hinting that the mind might be better at multitasking than previously thought.
"This is the first time we observe in the brain concurrent representations of distinct rewards," Etienne Koechlin, director of the cognitive neuroscience laboratory at the French National Institute for Health and Medical Research (Inserm) in Paris and coauthor of the new study, wrote in an email to ScientificAmerican.com.
For the study, 32 right-handed subjects were asked to match letters while their brain activity was recorded with functional magnetic resonance imaging (fMRI). Subjects were motivated by a monetary reward they would receive based on how many letters they matched without error. During this baseline test, both hemispheres of the brain's medial frontal cortex (which is involved in motivation) appeared active. However, when the researchers introduced a second task, where the subjects had to match like uppercase letters in addition to matching like lowercase letters with separately accruing reward tallies, Koechlin and his coauthor Sylvain Charron (of the same institution) found that the subjects' brains divided the two reward-based goals between the two sides of the region. The results were published online April 15 in Science.
The area of the brain that was highly active in the observed multitasking behavior, the frontopolar cortex (which organizes pending goals while the brain completes another task), is "especially well developed" in humans, Koechlin says. It helps organize tasks and the order in which their components should be completed (as highlighted by patients who have damaged this part of the brain and are especially poor at multitasking, he notes). This area's lesser development in other primate species leads Koechlin to think that the ability to hold more than one goal in mind at once might be unique to our species.
The new work does not, however, show that the brain can actually execute two distinct tasks, such as letter matching, at precisely the same time, Paul Dux a psychology lecturer at the University of Queensland in St. Lucia, Australia, noted in an email to ScientificAmerican.com. The data reveal that though separate goals might be running concurrently in the brain, "there are still large dual-task costs" when people have to switch between two tasks making for "non-efficient multitasking," cautioned Dux, who was not involved in the new research but has also studied attention in the brain. (Some commonplace activities, such as driving and talking on a cell phone frequently go hand-in-hand, but the brain is likely switching its main focus quickly between the two activities, perhaps a reason the pairing has been so dangerous.)
Although the letter-matching tasks were simple, Koechlin says that the same hemisphere split would also likely be observed in subjects performing more complex tasks. "Task complexity itself does not prevent from dual-tasking," he explains. "People should be able to switch back and forth between two complex tasks (by postponing one while executing the other one), provided that the incentive of pursuing each task is large enough." If one of the tasks sparks too many unrelated thoughts, however, "your frontal lobes should lose track of one task," he notes (perhaps providing more evidence for the hazards of distracted driving).
Within the results of Koechlin's work is an explanation for why people tend to prefer binary options, such as yes-or-no questions and if-then statements. "This finding further suggests that the frontal function cannot keep track of more than two goals/tasks at the same time," Koechlin explains. "Humans have problems deciding between more than two alternatives…. A possible explanation is that they cannot keep in mind and switch back and forth between three or more alternatives."
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20 Comments
Add CommentThese brain scan researchers are so single-minded!
Reply | Report Abuse | Link to thisThis test only detects a brain process that is effectively dedicated to visual processing. Since humans essentially have a singular visual process using two physical visual sensory input devices, there is little multitasking capability supported (although there are many subtasks that may be associated with it). For example, the two eyes are not independently capable of following two moving objects - unlike some lizards.
Conveniently designed experiment! If you could get those lizards to perform the same tasks, you would likely get different results.
Moving beyond processing dedicated to physical and sensory resource management, humans are quite capable of multitasking many abstract objectives. Unlike these researchers, many professionals have to concurrently manage many ongoing projects - each with ans intrinsic priority and schedule. It must be nice to be able to focus on one experiment at a time!
"Written goals are golem goals."
Reply | Report Abuse | Link to thisThe scientists may have chosen written goals to get precise fMRI images.
Instead they should design an game whose plot uses a multitab browser. Everybody will keep all the tabs' goals.
So it means that the brain can manage only 2 bare written goals areas but can handle much more beautiful goals areas.
With online poker my brother limits himself to 3 poker tables because his screen is too small.
It is an article about fMRI exploit more than putting a core 2 duo in your brains' taskbars.
So if you have 4 semantic variations you would need a paper and a pencil to help you track them.
Reply | Report Abuse | Link to thisOr you cannot change your point of view more than 2 times without preparation ? You're not HAL.
Rabe - "The scientists may have chosen written goals to get precise fMRI images."
Reply | Report Abuse | Link to thisExactly correct: the experiment was designed primarily to fit the limited capabilities of the measurement method employed rather than to fully assess the capabilities being studied. Results obtained by measuring visual tasks only apply to visual tasks and cannot be used to extend general conclusions about the capabilities of the whole brain. I'm presuming that people still have capabilities that extend beyond the operation of a game-boy...
reward? .. a myth perpetrated .. jump doggie, jump .. the ..drooling dog eager to oblige .. but wait a minute .. this is no dog .. this is the brain .. and not any brain, the brain of a human individual .. and need the proper enticement .. not bones, or sausages .. but money .. jump doggie, jump
Reply | Report Abuse | Link to thisWhy did it come to mind .. connected .. associated .. with Julian Janes notion of .. bicameral mind or brain .. evolution? .. consciousness evolved? .. and continues to evolve. All these ideas about .. one-task brain .. even dual-task brain .. just a stage in the evolution of consciousness. In light of what has been revealed .. about the brain, current notions reflecting upon the current state of consciousness evolution, another stage in its development.
Reply | Report Abuse | Link to thisPrevailing social stratification .. conditions consciousness .. kings and queens .. god's messages .. messages-in-the-heads for medieval and pre-medieval human individuals and .. notions of limiting capacities of the brain .. to merely a task at a time, for individuals in the current stage of consciousness evolution. Multi-tasking, a privilege, sort to speak, assigned only to computers or supercomputers, for that matter, whereas computers in vain trying to match up to, what is constantly revealed about the potential of the brain.
Consciousness engineered .. to suit social realities of the time, and the current prevailing social realities demand, proscribe for individuals to be unable to think beyond the duties that are assigned to them by societies, in how to be good workers, servants to the needs of the goals set, from the top, from societies overwhelmed by individual minorities.
Let's see, drummers can be beating completely different rhythms/accents/volumes with each hand (also alternating between a multitude of drums/cymbals/bells/percussion instruments), while each foot may be beating completely different rhythms/accents/volumes.
Reply | Report Abuse | Link to thisI count that as four distinctly different things happening simultaneously -- also while possibly listening to other band members to match volume, tempo, breaks, and perhaps even singing lyrics -- again matching pitch/volume/tempo/accent/enunciation. Which would bring the total up to 12 or more.
Who designed these tests?
why do people insist on thinking that driving is a single task? it's, by nature, a multi-tasking endeavor!
Reply | Report Abuse | Link to thisenough of this distracted driving crap. Funny how the part the author used as 'evidence' for distracted driving, I was thinking made the point against distracted driving:
" f one of the tasks sparks too many unrelated thoughts, however, "your frontal lobes should lose track of one task," he notes ..."
This would lead me to believe that if using a cellphone sparks 'too many' (notice how that's subjective) unrelated thoughts ... you stop paying attention to it ...
"... (perhaps providing more evidence for the hazards of distracted driving). "
How, in the scenario of driving while using a device, is DRIVING the goal which causes UNRELATED THOUGHTS that would force your brain to focus on THE DISTRACTION?
fel0nious - Identification of driving as a critical task is proven by those who die or are maimed as a direct result of non-responsiveness to the dynamic demands of driving. That inattentiveness resulting from intoxication or distraction produces increased incidences of terrible traffic collisions requires little study. It's clear enough that driving requires full attention to its constantly changing demands for critical responses.
Reply | Report Abuse | Link to thisThis study appears to be primarily an exercise in justifying a research group's fMRI access budget. The test seems to be designed more to exercise the equipment's capabilities than to definitively determine than mulitasking capabilities of the the human brain.
To those whose favorite tool is a hammer, every problem appears to be a nail.
This test has nothing to do with deep thought. It may be possible to do two recognition types of exercises together, but is it possible to write a thoughtful response and listen to jazz at the same time -- really listen? Or really write? Can a person really talk on the phone and drive a car at the same time, even without using hands on the phone device? Could this text screen be any more difficult to see? Oh, yes, if it was white on white or black on black. To continue, these types of studies are not only not useful but can be dangerous. They don't test anything that a person would have to do in today's real world, and they give people busy txting while reading the impression that they can and should be able to do many tasks requiring actual THOUGHT at the same time -- and they cannot. I'm a teacher. I see them screw it up all the time. Fortunately, they are not in a car when they screw up their course work.
Reply | Report Abuse | Link to thisi think this has more to do with learning. once something has been learned(ie programed) it runs along just fine with out drawing our attention unless it needs to or we want it to.
Reply | Report Abuse | Link to thisHi;
Reply | Report Abuse | Link to thisI have a PhD in biochemistry, and I believe that 2 tasks are about all I can handle. Performing an experiment, and suddenly getting a phone call could mean a ruined experiment. There its one task.
Driving and listening to music is two, and anything else is bad.
In Andhra Pradesh state of India are two famous age old exhibition games of intellectual prowess known as Ashtavadhana (Simultaneuous performance of eight tasks) and Satavadhana (performance of 100 tasks).
Reply | Report Abuse | Link to thisA Pundit is posed very tricky totally unrelated questions by seven people by turns, each question being spelt out only partially (a letter or a word) in each round. The Pundit has to remember, process and give the answer fianlly . An eigth man keeps distracting the Pundit's attention by beating a bell a different number of times in each round. The Pundit has to remember the number of times the bell rings in each round and correctly recollect the chimes at the end.
Similar is the case in Satavadhana (100 tasks) which of course comprises mostly writing poetry according to strict prosody of grammar.
It is true that a single task may be processed at any one time, but the brain has to keep track of several totally disparate things in the woriking memory and recall them at the end.
ramesam - Personally, those feats remind me most of driving home after shopping with several children and a wife in the car, all with something to say.
Reply | Report Abuse | Link to thisThose feats of pundits you describe are quite comparable to the demonstration chess masters sometimes perform, playing many games simultaneously.
Certainly peak performance on any one task is achieved by dedicating all effort to it, but the reality is that all of us must concurrently perform multiple tasks on as daily basis.
A good study on why people who disagree with others resort to name calling 'lizards' and other disparaging remarks seems to be needed in this age of internet communication. We need to challenge our beliefs and emotions in consideration that other people have something to say.
Reply | Report Abuse | Link to thisWhen I was young I could quite easily follow seven or eight distinct conversations from different tables around me in noisy pub. But since suffering from tinitus I find it hard to concentrate on even one conversation if there is any background noise. Women generally have no problems dealing with large numbers of offspring while concurrently doing several domestic tasks at the same time as they talk to several chatting neighbours.
Reply | Report Abuse | Link to thisdslaby - Not that I don't often enough deserve correction of my manners, but in this case I'm innocent. I was literally referring to some lizards ability to look in two different directions at one, spotting insect targets in either eye's field of view. This requires fully independent processing on imaging signals within the brain, something that we (and most other animals) can't do. Thanks, though, and please let me know when I do become overbearing - it's just a matter of time.
Reply | Report Abuse | Link to thisPerhaps a study should be done on the multi-tasking brains of great pianists, who must be thinking several melody lines at the same time. In early piano learning, one hand has the tune and the other assists that tune, or gets a simple harmony. But in advanced piano, the fingers individuate in far more complex ways. I know an accompanist who can sight-read an eight-part Baroque vocal score (without the benefit of a piano reduction score) where each vocal line has an independent melody. She can even transpose the score, on request.
Reply | Report Abuse | Link to thisThis probably isn't relevant to the study this article covers but I want to clarify something. Computers do not multitask. Computers multithread. A CPU executes exactly 1 command at a time. It may handle multiple threads of activity in a small amount of time but it does so 1 command from 1 thread at a time. Multi core computers may delegate some tasks to the extra CPUs but when these tasks are complete they still return to the primary CPU for result distribution which again is processed 1 command at a time. If you want computers to multitask then you need multiple computers.
Reply | Report Abuse | Link to thisIt is all semantics of course but for proper terminology as currently defined computers multithread and don't multitask.
jtdwyer - At least you know you become overbearing. It took me a couple of decades after highschool to realize that I have that flaw. Some people never figure it out.
Many things we do on an everyday basis do not necessarily require our full attention on an every moment basis. Doing two or more tasks that do not require this level of attention gives rise to the belief that we can multitask when what we are actually doing is more properly referred to as task-switching. Task-switching is switching back and forth between tasks sometimes at an incredibly rapid rate that may be fast enough to also fool us into believing that we are multi-tasking. The article alludes indirectly to this distinction between multitasking and task-switching by noting that the research does not demonstrate that the brain can execute two distinct tasks at the same time. If you have ever operated dangerous power machinery such as a bandsaw, you will have a good idea of what I mean by saying that we cannot multitask. Attempting to multitask while operating a bandsaw will likely cost you one or more fingers due to you not giving the task your full attention every moment. A simpler and much less dangerous exercise is to try to talk about one thing while simultaneously writing down something in a grammatically correct full sentence format different that is different than what you talking about.
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