Taak 5 Lose attention?
What is sustained attention and how can you measure it?
Sustained attention involves the maintenance of a focus of attention over al relatively
long period of time. Experiments also suggested that the amount of time for which
attention could be focused on a single object or idea was extremely limited, a matter of a
few seconds. Detection efficiency markedly declined after aout 30 minutes or so, even
highly motivated.
What is the signal detection theory?
Matthews (2000). Vigilance and sustained attention.
6.2 Signal detection theory and vigilance
The Signal Detection Theory (SDT) proposes that sensory evidence about actual or
potential signals is received by a noisy nervous system, and that a separate decision
process acts upon such evidence to determine whether or not a detection response
should be made. Signal detection responses are thus the joint outcome of the operation
of sensory and decision processes.
The figure can be thought of as representing the strength of the sensory evidence or the
magnitude of the sensory impression received by the observer. Since in the majority of
vigilance situations it is difficult to discriminate signals from noise, there is a considerable
area of overlap between the noise and signal + noise distributions as the figure indicates.
In the region of the overlap, it is virtually impossible to determine whether the strength of
the sensory evidence is indicative of the presence of a signal or is simply attributable to
noise. Observers are assumed to resolve this dilemma by setting a criterion level for the
strenght of the sensory evidence they receive, and to report the presence of a signal only
if they judge that this level has been exceded.
The figure illustrates the distinction between sensory and decision processes suggested
by SDT. The detectability of a signal depends on the difference between the means of the
noise and signal + noise distributions, and is indexed by d’ (d prime). The greater the
overlap between the two distributions, the lower the value of d’, and the more difficult it
becomes for the observer to discriminate signals from background noise. The same index,
d’, is lso used to refer to the observer’s (perceptual) sensitivity. Readiness to respond
relates to the value of the response criterion, whcih is designated as β. There are two
possible values for β , β1 and β2.
Conservative (high) response criterion β2. that is, the observer will respond only if
the strengthy of the sensory evidence that a signal is present is judged to be relatively
1
What is sustained attention and how can you measure it?
Sustained attention involves the maintenance of a focus of attention over al relatively
long period of time. Experiments also suggested that the amount of time for which
attention could be focused on a single object or idea was extremely limited, a matter of a
few seconds. Detection efficiency markedly declined after aout 30 minutes or so, even
highly motivated.
What is the signal detection theory?
Matthews (2000). Vigilance and sustained attention.
6.2 Signal detection theory and vigilance
The Signal Detection Theory (SDT) proposes that sensory evidence about actual or
potential signals is received by a noisy nervous system, and that a separate decision
process acts upon such evidence to determine whether or not a detection response
should be made. Signal detection responses are thus the joint outcome of the operation
of sensory and decision processes.
The figure can be thought of as representing the strength of the sensory evidence or the
magnitude of the sensory impression received by the observer. Since in the majority of
vigilance situations it is difficult to discriminate signals from noise, there is a considerable
area of overlap between the noise and signal + noise distributions as the figure indicates.
In the region of the overlap, it is virtually impossible to determine whether the strength of
the sensory evidence is indicative of the presence of a signal or is simply attributable to
noise. Observers are assumed to resolve this dilemma by setting a criterion level for the
strenght of the sensory evidence they receive, and to report the presence of a signal only
if they judge that this level has been exceded.
The figure illustrates the distinction between sensory and decision processes suggested
by SDT. The detectability of a signal depends on the difference between the means of the
noise and signal + noise distributions, and is indexed by d’ (d prime). The greater the
overlap between the two distributions, the lower the value of d’, and the more difficult it
becomes for the observer to discriminate signals from background noise. The same index,
d’, is lso used to refer to the observer’s (perceptual) sensitivity. Readiness to respond
relates to the value of the response criterion, whcih is designated as β. There are two
possible values for β , β1 and β2.
Conservative (high) response criterion β2. that is, the observer will respond only if
the strengthy of the sensory evidence that a signal is present is judged to be relatively
1
