It is believed by scientists that rather than simultaneous attending to all tasks at once, what really happens during multitasking is a rapid change of focus between tasks. While research supports the fact that “highly practiced skills can be easily performed while one is thinking about something else, but the addition of a task that requires decision making switches ones attention to that task.
When people perform higher level tasks, they are using the cognitive function called “executive control” This function is housed in prefrontal cortex. The part of the brain associated with perception and thinking. Executive control is the brains supervisor for most cognitive functioning. It establishes priorities, decides what tasks are the most important, and assigns mental resources to completing the tasks.
Executive control has 2 main activities: goal shifting and rule activation. Although these activities take only several tenths of a second, the repeated need to switch between tasks can add extra time for performing both tasks.
Management of short term memory is another fundamental aspect of multitasking.
Factors affecting multitasking behaviours and information task switching.
We are learning a lot more each day. Advance of brain imaging and functional brain imaging (what our brain does when we challenge it) has clarified us to what happens when we multitask.
Our brains are not very adapted for multiple streams of information at the same time but rather focussing at a paticular direction. When we do things that require a great deal of attention as compared to walking while chewing gum what happens is we switch between two things. And with each switch there is cost of performance that occurs.
A surprising discovery tells us that people who multitask most frequently think they are the best at it. But actually thay are the worst at any important task at multitasking.
One might question then what are the so called multitaskers good at?
A study revealed that when we talk on phone while driving we get better at it with time. What actually happens is that they filter out the road as they are involved in a conversation. As ironically high multitaskers are bad at filtering out the road actually see the road more and drive a little better.
Swithching of attention occurs in a region right behind the forehead called Brodmann’s Area 10 in the brain’s anterior prefrontal cortex as seen in MRI. Area 10 is part of the frontal lobes, which “are important for maintaining long-term goals and achieving them” .
“The most anterior part allows us to leave something when it’s incomplete and return to the same place and continue from there”.This gives us a “form of multitasking,” which is actually sequential processing. Because the prefrontal cortex is one of the last regions of the brain to mature and one of the first to decline with aging, young children do not multitask well, and neither do most adults over 60.
It’s our desire and need to be engaged to novelty, its well known that novel stimuli or enviorment arouse the reward system and this is part of what allowed us to be engaged by novelty. Multitasking has a higher novel load and to continiously switch to a new task feels exciting. This sort of interaction with multitasking leads to addictive levels in people. And people crave for this type of stimuli.
Research reveals that most high multitaskers believe that new information is better than old information.Where as low multitaskers believe that the information they are working with is more valuable.It is seen that younger people look at information because they feel something thrilling is happening out there, for older people who check their e-mails don’t want to “get away”.
Stress and hormonal activity:
Whenever demands exceed abilities, stress is bound to follow. Multitasking is espicially stressful when the tasks are important, as they often are on the job. It’s said that brain responds to impossible demands by pumping out adrenaline and other stress hormones that put a person
“on edge”. These hormoes provide a quick burst of energy won’t make multitasking easier. Just like an old pickup can’t go 150 miles per hour no matter how much fuel you put in he tank or how hard you step on the gas.
Over time of stress of multitasking may even become dangerous. Results show that a steady flow stress hormones can strain the body and threaten the health. As recently reported by the American National Institute for Occupational Saftey and Health, numerous studies found out that on-the-job stress can cause headache, stomach problems and sleep disorders. Chronic work-related problems can lead to chronic problems includind back pain, hear disease and depression.
Studies reveal that our bodies release hormone called cortisol during stress, caused due to multitasking. Cortisol is needed to carry out various functions in the body but incresed levels of cortisol results in high BP, sleep problems, weakness of immune system, imbalances in blood sugar levels etc.
Deep hard thinking, the type required when we write a paprer or read a complicated news story, has been tremendiously compromised . Multitasking either prevents you to do that or wonderfully allows us to avoid it.
Broadbent’s theory of selective attention, is based on his dichotic listening experiments that required his subjects to shadow speech messages in one ear while ignoring the messages in the other ear. Broadbent concluded that little if any content from the non attended ear is remembered. From these observations Broadbent proposed that there is limited porcessing channel that information is filtered through from a sensory porcessing stage on its way to a short-term memory store or buffer. From here information may be processed further before being transmitted into a long-term memory store. When this channel becomes over loaded, such as in dichotic listening experiments, some of the information is filtered out while other information is selected for further processing.The filtering mechanism selects inputs based on different physical cues from the stimulus input, such as location in space, and/or frequency.
Vocal music can be distracting while instrumental music can aid in learning as it helps funnel out distractions in few people.
Various experiments are conducted where participants are asked to learn a list of words presented visually while listening for the occurrence of certain digit strings presented through the adiutory channel. They are then tested for memory of the word list. Different variations have been investigated including different modalities, the same modalities, task difficulty, the effects of practice, the effects of eother primary or secondary task on performance, and testing during encoding and reterival. Almost without exception performance on one or both tasks suffers a decrement as a direct result of having to perform the two tasks simultaneously.
Beeps in study disrupted declerative memory (eg. When we recall what we did last weekend).For tasks performed with distractions hippocampus of the barin was not involved (necessay for processing, storing and recalling information. But infact the straitum was involved. Straitum is a part of brain system that underlies our ability to mearn new skills. Multitasking makes it more likely to rely on striatum to learn. Thus multitasking changes the way people think.
In an investigation performed by Australian College of Road Saftey interaction between visual impairment and multitasking was performed. It revealed that multitasking (like talking on the phone or using in-vehicle navigational devices) had a significant detrimental impact upon driving performances. Multi-tasking further exacerbated the effects of visual impairment, where the visual dual task had a greater detrimental effect on driving performance than the auditory dual task (p<0.05), particularly for the older drivers. The implications of these findings are far reaching in modern society where the driving and in-vehicle environments are becoming increasingly complex.
An experiment was performed to find out the effects of multitasking on muscle activity . Muscles of the upper extremity were examined.The thesis inspected concurrent grip and shoulder extensions with additional and simultaneous demands of task precision and mental processing. It concluded that incerased mental loads, when combined with physical work, have the potential to interfere with task performance and likely elicit elevated levels of muscle activity.
Some research shows the relationship between stimulation and performance forms a bellcurve: a little stimulation–whether it’s coffee or a blaring soundtrack–can boostperformance, but too much is stressful and causes a fall-off.