|
|
 |
True
|
Correct
Like
sleepiness and alertness, mental and physical performance display
circadian rhythms and performance differences over the day. For
example, peak physical performance occurs in the late afternoon
as summarized below. While performance testing is considered a
motivated behavioral situation, potential variability due to time
of day should be ameliorated.
| Figure
3.5.1: Daily Time Periods of Maximum Physical Performance
and Peak Stress Hormone Levels
|
|---|
|
|
|
Mental
functions, pain tolerance, and mood have also been shown to have
circadian variability as summarized in the following chart.
| Table
3.5.1: Demonstrating Circadian Variability
|
|---|
| Morning
(about 8am to noon)
| Afternoon
(about noon to 4pm)
| Evening
(about 4pm to 8pm)
|
|---|
| Short
term memory and concentration peaks | Mental
arithmetic and logic peaks | Long
term memory and repetitive tasks peak |
| Pain
tolerance high | | Pain
tolerance low |
| Cheerfulness
peaks | | Cheerfulness
and friendliness low |
| Anxiety,
fatigue and hostility low | | Anxiety,
fatigue and hostility peak |
|
Comparative
performance differences rarely have been reported among insomnia
subtypes. The features of mental performance that can be tested
are many and this area deserves more intensive study. However,
as an example, Bonnet and colleagues assessed cognitive and physical
performance in subjects matched for age, gender, and weight with
both psychophysiological-type and sleep state misperception-type
insomnia. They did this at the end of the second night of PSG
sleep in the laboratory (in the early morning) for all subjects
(Bonnet
and Arand, 1995; Bonnet
and Arand, 1997). Two performance measures as means ±
SD are shown as follows:
| Table
3.5.2: Cognitive and Physical Performance Assessment
|
|---|
| Mental
Performance
| Insomnia
PPI
| No
Insomnia
| P
Value
| Insomnia
SSM
| No
Insomnia
| P
Value
|
|---|
| Short
term memory words
|
5.7
(3.7)
|
7.2
(2.7)
|
0.02
|
7.2
(3.7)
|
7.8
(2.7)
|
NS
|
|---|
| Vigilance
P(A)
|
0.875
(0.15)
|
0.871
(0.16)
|
NS
|
.892
(0.12)
|
.942
(0.09)
|
0.01
|
|---|
|
It
is interesting to note that psychophysiological-type insomnia
that involves sleep loss and perhaps discontinuity of sleep, appears
to be associated with short-term memory impact while insomnia
without physical sleep disruption (detectable by PSG) shows no
link to short-term memory but is associated with vigilance or
concentration differences.
|