Closure of
the secondary task
This is a
short note on the closure of the secondary task when attention is divided
between a primary and secondary task.
"Ergonomically
speaking, when one has a multi-task assignment, the primary task is the one
that takes priority. That is, it is the task that should receive the largest
amount of allocated mental and physical resource. All other tasks in the assignment
are dealt with in later order.[1]"
"Ergonomically,
any job which is subordinate or incidental to the primary job where multiple
tasks are required for completion.[2]"
From the
point of divided attention the secondary task does not have to be related to
the aim or context of the primary task. Listening
to music while driving a car for example.
The
attention necessary for the primary task may be reduced in some cases. Predictability, repetitiveness, processing
speed of events that have to be perceived are some of these.
The
reduction of attention resources for the primary task increases the resources
of the secondary task.
Also the
increase of need for attention resources for the primary task reduces the
resources for the secondary task.
While
driving and listening to radio at the same time, in the case of a difficult
situation, the driver does not hear the radio anymore (-till the emergency is
solved).
In the case
of emergency, the second task closes temporarily without conscious
decision.
This
automatic closure of the secondary may become a deadly danger when primary and
secondary tasks are mixed unintentionaly.
Talking
while driving may cause a similar risk if the talk becomes serious and
elaborated. The secondary task, namely 'talking'
gets hot and the driver does not become aware that his primary task, 'driving'
has become 'secondary'.
The worst of
it happens when the 'talk' becomes the primary task and causes the second task,
'driving's closure automatically. The
driver does not notice that he is not in control of the vehicle.
Technically
speaking, the man machine embodiment has been destroyed and situation awareness
is lost.
This is one
of the reasons we sometimes suddenly wake up to a risk on the road and try to
correct it.
[1,2]
Nugent, Pam M.S., PsychologyDictionary.org, April 28, 2013
