Today it is increasingly common to find us in multitasking condition, because the technology at our disposal invites us to perform multiple tasks simultaneously, for example, the possibility of keeping several windows open simultaneously on the desktop, which is the first development of the paradigm of direct manipulation (Schneiderman, 1998), allows us to perform many different tasks at the same time.
While multiple windows, instant messaging, email and notification programs promote the development of multi-tasking and the illusion of greater efficiency, on the other hand can have very negative effects. A study conducted by V. M. González and G. Mark (“Constant, Constant, Multi-tasking Craziness”: Managing Multiple Working Spheres) has determined that the employees in the office can not stay focused for more than three consecutive minutes before being interrupted by a phone call, an e-mail or a colleague. Another recent survey by the European Foundation for the Improvement of Living and Working Conditions, shows that a third of the occupied of the European Union states to be often or very often interrupted during work.
Living in a constant state of multi-tasking involves a great deal of energy and cognitive resources. The working conditions in multi-tasking is only illusory, in fact our brain is able to quickly switch from one task to another, but always works in series unless one of the two tasks is not sufficiently simple or repetitive that not require attentional processing.
For example, this is the case when we drive and talk simultaneously. The act of driving has become automatic. However, if the main activity becomes complex or simply new, unusual we tend to suspend all other tasks. In heavy traffic or when trying to navigate in a new city you interrupt the conversation or turn off the radio just because of the fact that the difficulty of the primary task saturated the capacity of attention and information processing.
The Cognitive Psychology tried to develop specific tools to measure the degree of mental fatigue by introducing the idea of Mental Workload, based on the concept that the human cognitive system has limited capacity to process information in input . There are several ways to measure the mental workload:
- behavioral measurements:
we measure the number of errors in performing the secondary task while performing the primary one, for example, may be required to perform calculations (primary task) and press a button when a light is turned on (secondary task). As the complexity of the calculations the number of errors or delays in the calculations increase.
- Subjective Measurements:
They mainly consist on standard questionnaires that, after the execution of a task, require to answer one or more questions that reveal the perception of difficulty in the task carried out. Among the most widely used questionnaires there is the NASA Task Load Index.
- physiological measurements:
provide an estimate of the mental workload based on the intensity of physiological arousal such as increased heart rate, brain potentials evoked, pupil dilation, breathing, changes in hormone levels, etc..
- behavioral measurements:
The Department of Transportation of the United States estimates that talking on a cell phone while driving can be one of the causes in the 50% of accidents. Talking on the phone (secondary task) diverts resources from the primary task (driving) and the risk of accidents increases by four times. Using the headset or hands-free, in spite of legislation, would not cause any significant difference.
In case of prolonged exposure to high mental workload also cognitive skills, as well as with the physical, deteriorate. In general, mental fatigue can be defined as a condition of malaise and reduced efficiency, due to an excessive and prolonged effort, which leads to a reduction of the ability to respond to stimuli in the external environment.
In these conditions it can be observed a reduction of the visual space which is normally approximates to 180 ° (“tunnel vision”).
There are three types of fatigue:
- Acute: it arises from a intensive labor effort carried out in a short time (much like the mental overload);
- Chronic: follows a prolonged work commitment of varying intensity;
- Circadian: linked to the sleep-wake cycle and due to an alteration in the rhythm itself (as happens in night work), or insufficient or inadequate rest.
Unlike the physical load, the effects of which can be neutralized by simply short breaks and restructuring of the task, mental fatigue is recovered only through prolonged periods of rest.
The issue of the efficiency and the mental fatigue in modern tasks recently started to be studied especially in relation to another specific condition: the ability to handle interruptions.
The problem lies not in being interrupted, but in the time (resumption lag) that is used to retrieve the concentration of our activities.
However, if the tasks are simple and repetitive voluntary interruption of these can even become positive especially if the interruption is considerable “entertainment” (e.g. browsing on social networks). Some studies have tried to show that people can simultaneously read and write text. The smallness of the samples used, the assumption that one of the two tasks has become automatic or that the repetition of the exercise has trained individuals to perform very abrupt changes of attention, however, lead to suppose that the subjects do not have demonstrated multi-tasking abilities.
Someone, like David Silverman, entrepreneur, writer and expert business support that the computer multitasking systems made possible to conceive systems on which any unexpected event can be handled immediately without waiting for its extreme consequences, justifying such a way that even for people this work mode is ultimately more productive ensuring a greater number of information to the worker.
Beyond the various studies, the Greeks already knew that our mind can not concentrate simultaneously on two operations, two different ideas or decisions, as shown by this Aesop’s fable:
“A Fox once saw a Crow fly off with a piece of cheese in its beak and settle on a branch of a tree. <<That’s for me, as I am a Fox,>> said Master Reynard, and he walked up to the foot of the tree. <<Good day, Mistress Crow,>> he cried. <<How well you are looking today: how glossy your feathers; how bright your eye. I feel sure your voice must surpass that of other birds, just as your figure does; let me hear but one song from you that I may greet you as the Queen of Birds.>> The Crow lifted up her head and began to caw her best, but the moment she opened her mouth the piece of cheese fell to the ground, only to be snapped up by Master Fox. <<That will do,>> said he. <<That was all I wanted. In exchange for your cheese I will give you a piece of advice for the future: <<Do not trust flatterers.>> The man can also think very quickly, but always and only an idea at a time. Can be attracted to more stimuli, but always one at a time. Can be prey to more feelings, but always one at a time.
Hell to pay to the manager, who hopping from one task to another or addressing multiple situations, wants to be considered the king of the manager.
For the vanity to demonstrate his ability of multitasker he is doomed to fail.
He’ll go the way of the crow!