Does Being Monitored during Sleep Affect People on a Cognitive

and a Behavioral Level?

M. S. Goelema

1,2

, R. Haakma

and P. Markopoulos

Philips Group Innovation Research, Eindhoven, The Netherlands

Department of Industrial Design, Eindhoven University of Technology, Eindhoven, The Netherlands

Keywords: Self-monitoring, Reactivity, Wearable Devices, Sleep.

Abstract: Nowadays it is possible to monitor behavior or physiological features with specially-made devices that

make self-monitoring an accessible and simple activity. Unknown is the effect these wearable devices may

have on people’s lives and this also applies to the area of sleep monitoring devices. The aim of this

preliminary study is to address the extent to which sleep monitoring devices affect people on a cognitive and

behavioral level. Four participants aged from 34 to 60, filled out a sleep diary for three consecutive weeks

and wore in the latter two weeks a sleep monitoring device. Adjustments on a cognitive and behavioral level

were observed, but this was probably due to participating in this study and completing the sleep diary as was

indicated by the participants. Since the market for self-monitoring devices is rapidly developing and more

accessible for lay people, it is important to investigate the reactive outcomes of these devices as they may

have consequences for people who have a high adherence to self-control. Moreover, the knowledge about

self-monitoring will improve which will lead to better interventions carried out by, for example, sleep

coaches.

1 INTRODUCTION

An international collaboration between users and

producers of self-tracking devices has emerged,

called the ‘Quantified Self’ (www.quantifiedself.

com). By exchanging information and with reviews

of the products they keep each other updated. Due to

the monitoring, users achieve more knowledge about

their bodily functions and performance during the

day. Self-tracking devices may additionally operate

as an aid for interventions. The collected data are

then transferred to a ‘personal’ coach, for example,

through an application on the mobile phone. These

coaches are able to advice and monitor patients

remotely and for a sustained time period. Self-

tracking devices utilized for these kind of purposes

are rising (LeMaster et al., 2008; Going et al., 2003).

According to Swan (2012) the health care industry is

shifting towards an approach of personalized

preventive health maintenance and away from an

exclusive attention to disease treatment. For self-

monitoring this means that due to the development

of wearable devices the possibility emerges to

monitor unaware processes, such as physiological

features, instead of relying on self-reports.

Previous literature in diverse research areas

shows that when self-monitoring is used as an

intervention, successful results are obtained, for

example: weight loss (Burke et al., 2011; Boutelle

and Kirschenbaum, 1998; Wang et al., 2012; Butryn

et al., 2007) improved academic performance

(Amato-Zech et al., 2006; Maag et al., 1993;

Shimabukuro et al., 1999) control of blood glucose

levels (Karter et al., 2001; Martin et al., 2006) and

less substance use (Litt et al., 1998; Helzer et al.,

2002), although sometimes the effect of self-

monitoring is small or not found (Hufford et al.,

2002; O’kane et al., 2008). These results make the

effect of self-monitoring ambiguous, which may

have several causes, such as different study

populations (different size and patient populations),

diverse methods used and variable duration of the

studies.

Much attention has been paid to the reactivity of

self-monitoring. Reactivity is a phenomenon that

occurs when individuals adjust their performance or

behavior due to the awareness that they are being

observed (Korotitisch and Nelson-Gray, 1999). Self-

monitoring consists of two processes: firstly, self-

observation: one must discriminate or notice the

S. Goelema M., Haakma R. and Markopoulos P..

Does Being Monitored during Sleep Affect People on a Cognitive and a Behavioral Level?.

DOI: 10.5220/0004745700270033

In Proceedings of the International Conference on Health Informatics (HEALTHINF-2014), pages 27-33

ISBN: 978-989-758-010-9

 2014 SCITEPRESS (Science and Technology Publications, Lda.)

occurrence of the target behavior. Secondly, self-

recording: one needs to record when the target

behavior is occurring (Korotitsch and Nelson-Gray,

1999). Kazdin (1974) investigated with the

performance on a sentence-construction task,

different aspects of self-monitoring, such as

response desirability, goal setting and feedback.

They found several interesting results, but

particularly relevant in this case were: (i) supplying

a performance goal or feedback enhanced the

reactive effects of self-monitoring, (ii) monitoring

one’s own behavior or being monitored by someone

else was equally reactive, (iii) the process of self-

recording, independently of observing the results,

led to behavior change. These results indicate that

when a person purely monitors himself, reactive

behavior is seen. Moreover, the impact of the

adjusted behavior can be augmented by setting a

goal and/or providing feedback and an insight in the

observed data is not necessarily needed to alter

behavior.

The study of McFall (1970) shows that effects of

self-monitoring can occur even without the

determination of a goal. The participants were not

motivated to stop smoking and every effort was

made to minimize the participant’s motivation to

stop smoking during the study period. After 13 days

of self-monitoring the frequency of having a

cigarette significantly increased in comparison to the

baseline condition, where the participants were

secretly monitored by others. The long-lasting effect

of a behavior modification after self-monitoring is

unclear and longitudinal studies are needed to

provide more insight in this matter. Subsequent

studies after the 70s put more emphasis on self-

monitoring as a tool for an intervention as opposed

to investigating the aspects related to the process of

reactivity of self-monitoring.

A recent article illustrated the possibility of

reactivity in the baseline assessment of physical

activity when using an accelerometer device (Motl et

al., 2012). Two identical studies were carried out

wherein persons with multiple sclerosis (MS) wore

an accelerometer for seven days to collect baseline

data and one week later wore a pedometer over a

seven days period (first week of a behavioral

intervention). They found a decrease of the average

steps per day over the first week of the behavioral

intervention compared to baseline measurements.

Apart from the study of Motl et al. (2012),

underemphasized are the consequences wearable

devices may have on a cognitive and behavioral

level.

This study investigates the reactivity effects of

wearing a monitoring device during sleep. As where

it is unclear to which extent people are affected

when being monitored during sleep, although one is

able to monitor their sleep at their own home and

independently. Being monitored during sleep,

regardless of the subconscious state of sleep, may

influence the behavior before going to bed as well as

the behavior after waking up. Additionally, persons

may modify their cognitions about sleep because

they become more aware of their sleeping habits. As

a result, the device might show different results than

it otherwise would have shown (normal night

without monitoring). Sleep studies have traditionally

required users to fill out a diary every morning

(Carney et al., 2012; Keklund and Åkerstedt, 1997),

but the opportunity arises to support sleep studies

with a monitoring device for the home or to replace

the diary altogether.

The sleep monitoring devices, available on the

consumer market, all postulate that they are

unobtrusive in a way that they do not disturb people

during their sleep. Nevertheless, they can have an

effect on a cognitive and behavioral level, but this

has not been researched. As a result, with the current

development of sleep monitoring devices

increasingly being used by lay people, the aim of

this explorative study is to address the extent to

which sleep monitoring devices affect people on a

behavioral and cognitive level. In this study the self-

monitoring is occurring automatically and no

specific attention is needed and no goal is set or

feedback is given. Moreover, the awareness of being

monitored plays an important role in this study.

2 METHODS

2.1 Participants

For this study four adults were recruited, aged

between 34-60 years. Men and women were equally

distributed. All participants stated that they do not

experience any sleeping problems, but one of the

participants reported sleeping somewhat different

than usual at the time of the study because of her

pregnancy. The participants were blind to the

experimental hypotheses and were told that the

purpose of this study was to research the overall

sleep experience when being monitored during

sleep.

2.2 Measures

The sleep quality at baseline was measured with the

HEALTHINF2014-InternationalConferenceonHealthInformatics

Pittsburgh Sleep Quality Index (PSQI) questionnaire

which determines sleep quality and disturbances

over an one-month time interval (Buysse, et al.,

1989). Based on a cut-off score of 5, participants can

be categorized into “poor” sleepers (> 5) or “good”

sleepers (≤ 5) The PSQI consists of 19 self-rated

questions, divided into seven components:

subjective sleep quality, sleep latency, sleep

duration, habitual sleep efficiency, sleep

disturbances, use of sleep medication and daytime

dysfunction. An overall PSQI score was calculated

from the seven components with a score range

between 0 and 21 and higher scores reflect worse

sleep quality. The sensitivity and specificity of the

PSQI are respectively 89.6% and 86.5% (Buysse et

al., 1989). In our sample it turned out that the two

men had a score of lower than 5 as where the women

had a score of 6. This suggests that the women may

have some sleeping problems. However, the scoring

range of sleeping problems runs from 6 to 21. The

score of 6 falls in the lower end of this range.

The sleep monitoring device used in this study

was the Actiwatch by Philips (Figure 1). It was

developed to distinguish between physical activity

and rest, and it is widely used in the sleep field for

detecting sleep-circadian rhythm disorders. The

Actiwatch uses an accelerometer to detect and log

wrist movement, also known as actigraphy that

indicates gross body movement. The model worked

with was the Actiwatch Spectrum; it weighs 21 g,

measures 31 x 28 x 10 mm and has a maximum

sampling frequency of 32 Hz (Philips / Respironics,

URL: http://www.healhcare.philips.com). The

Actiwatch feels and looks like a standard wristwatch

and was used as a tool to measure the effect of being

monitored during sleep as unobtrusively as possible.

As we believe the Zeo headband (Shambroom et al.,

2012) is more obtrusive to wear during sleep than a

wristwatch, since most people are already used to

wear a watch and not to wear a headband. In

addition, Cole et al., (1992) found that when

comparing polysomnography with actigraphy, a

wrist actigraph is able to measure sleep/wake

parameters relatively accurately.

Subjective sleep experience was assessed by the

Consensus Sleep Diary (CSD; Carney et al., 2012).

The CSD was developed with the intention that it

should be a consensus and standardized sleep diary

for sleep researchers, who before its development

would use a variety of divers diary formats.

For this study the core CSD was used

which

consisted of 8 items, including questions about

initiating and maintaining sleep as well as a

global appreciation of sleep (Table 1). Moreover, an

Figure 1: The Actiwatch Spectrum.

additional question was added to the diary whether

the participant was well rested the next morning, to

assess an insight in the sleep experience after

wearing the device. In addition, to obtain a more

complete answer on the behavioral effect of being

monitored another question was affixed to the diary,

namely: ‘What did you do in the last hour before

going to bed?’.

Table 1: Consensus Sleep Diary-Core.

Consensus Sleep Diary-Core

1. What time did you get into bed?

2. What time did you try to go to sleep?

3. How long did it take you to fall asleep?

4. How many times did you wake up, not

counting your final awakening?

5. In total, how long did these awakenings

last?

6. What time was your final awakening?

7. What time did you get out of bed for the

day?

8. How would you rate the quality of your

sleep? (very poor, poor, fair, good, very

good)

Three structured interviews were held to analyze the

cognitive and behavioral effects of sleep monitoring.

The questions in these interviews are self-made and

deal specifically with how participants experienced

the device and questions concerning the cognitive

and behavioral effects of wearing the sleep

monitoring device. Examples of questions are: ‘Did

you feel the device last night?’, ‘Did you wake up of

the device last week?’, ‘Did you think more of your

sleep during the two weeks of being monitored?’,

‘Did you change any sleeping habits during the two

weeks of being monitored?’ and ‘Did you sleep

differently last week?’. In all three interviews the

same questions were asked, including open as well

as closed (with response options) questions, and

some questions were only asked in the last

interview, as a consequence of withholding the

purpose of this study.

DoesBeingMonitoredduringSleepAffectPeopleonaCognitiveandaBehavioralLevel?

2.3 Procedure

At the start of baseline phase, the demographic

variables like age, gender and the PSQI were

assessed to characterize the sample. To establish

how sleep was when not being monitored by a

device, participants completed a sleep diary for a

week prior to the two weeks of wearing the

Actiwatch. In addition, participants also maintained

the sleep diary during the two weeks of being

monitored by the Actiwatch, as the sleep diary

contained supplementary questions about sleeping

habits. Participants were instructed to wear the

Actiwatch when they went to bed and to take off the

Actiwatch after the final awakening. During the two

weeks of wearing the Actiwatch the three interviews

were executed; after the first night, after one week

and after two weeks. The reason for the time period

of this study was that participants needed to get used

to wearing the Actiwatch. In the last interview

participants were debriefed regarding the purpose of

this study and questions were answered.

3 RESULTS

All participants answered to the question ‘if they

changed any sleeping habits’ negatively. However,

further on in the interview it became clear that one

participant did not drink any coffee anymore after

dinner time and tried not to work after 10:00 pm

(Table 2). As was indicated by the participant, this

adjustment was probably a result of participating in

this study. The same participant wanted to change

the time of going to bed due to filling out the sleep

diary, but did not succeed because of other

obligations. The three other participants did not

change any sleeping habits during the study period.

Participants held a particular regularity in their

activities before going to bed, according to the

answers given in the sleep diary. The most

prominent activity performed before going to bed

was watching television, closely followed by

browsing the web and reading. The activities

showering and having a conversation were also often

referred to. In addition, the bedtimes of the

participants did not vary between the week of non-

monitoring and the two weeks of being monitored

by the device, as was shown in the Actiwatch data

and the sleep diary (Figure 2). As answered in the

last interview participants did not have the feeling of

having slept differently when being monitored

during sleep.

On a cognitive level, two out of four did think

more about their sleep but stated that it was more a

result of filling out the diary than of wearing the

sleep monitoring device (Table 2). By completing

the sleep diary these two participants got more

conscious about their sleeping times. As said earlier,

one of those participants tried to shift the time of

going to bed to an earlier time, but accomplishing

that was harder than expected because of other

obligations. Two participants did not show any

adjustments on a cognitive and behavioral level. One

of the latter two had a strong ‘Big-Brother is

watching you’ feeling during the study, but as was

indicated by the participant, this feeling would be

less when being monitored for own purposes.

Table 2: Results of reactivity in this study.

Cognitive

changes

Behavioral

changes

Participant 1 Went to bed later

than expected.

Did not drink coffee

anymore after dinner

time. - Tried not to

work after 10:00 pm. -

Tried to go to bed

earlier but failed due

to other obligations.

Participant 2 Did not sleep as

much as thought.

No changes in

behavior towards

sleep.

Participant 3 No changes in

thoughts about

sleep.

No changes in

behavior towards

sleep.

Participant 4 No changes in

thoughts about

sleep.

No changes in

behavior towards

sleep.

Note. The cause of the changes above is not clear.

Figure 2: The diary bedtimes of the three weeks, displayed

separately for each participant.

HEALTHINF2014-InternationalConferenceonHealthInformatics

With regard to wearing the Actiwatch, after

wearing the device for the whole study period two

out of four did not feel the device anymore. The two

other participants still felt it a bit because of the

dimensions of the device and one of the latter two

was not used to wear a watch during the night. To

the question ‘if the device bothered them’ they all

responded negatively and their sleep was not

affected by the device. Two participants would wear

the device in the future, but then for limited periods

only.

4 DISCUSSION

This preliminary study shows adjustments on a

cognitive and behavioral level, but could not

separate whether these were due to the monitoring

device or hose to participation in the study as such,

and the daily diary keeping, as was indicated by the

participants. Completing the sleep diary was more

excitatory than wearing a sleep monitoring device. It

was expected that due to wearing the sleep

monitoring device people would pay more attention

to their sleep. However, in this study, two out of four

did not think more about their sleep. One

explanation may be that, apart from the awareness of

being monitored, utilizing the device was

commissioned by this study and probably the

participants were not interested enough in the

subject of sleep for themselves. This means that they

focused their attention to other concerns rather than

to their sleep or sleep related properties. The

medium obtrusiveness of the device may have

played a substantial role in this as well. Moreover,

the results may be dissimilar when there were

participants involved who experience sleeping

problems, but this point will be discussed in more

detail later.

Regarding the effect of being monitored during

sleep on a behavioral level, one participant did not

drink any coffee more after dinner time and tried not

to work after 10:00 pm. What the cause is of this

change is unclear. However the participant indicated

that due to participating in this study, the thought

about sleep increased and the participant decided to

carry out this behavioral change (also known as the

Hawthorne-effect). Additionally, the same

participant tried to modify his or her bedtime

because of filling out the diary, but failed to go to

bed earlier because of other obligations. No

behavioral changes were observed for the other three

participants. Kazdin (1974) proved with their study

that when setting a goal or providing feedback the

effect of change in behavior augmented. In our study

no goal was set and no feedback was given. Despite

this, our research indicates some behavioral

changes, even with the open setting of this study and

this is in comparison with the study of McFall

(1970).

As mentioned before, being active with the sleep

diary had a much greater impact on the study results

than expected. This means that solely completing the

sleep diary could have had a similar effect. Expected

was that filling out the sleep diary would become

more an automatic process, as is shown in several

other studies (Litt et al., 1998; Stone et al., 2003). To

know in the future whether these outcomes

attributed to completing the diary or wearing the

device, these measurements should become separate

conditions in a study setup. However, due to the

self-report nature of interviewing, the results found

in this study still can be a result of the process of

reactivity on wearing the device. Besides this, the

results found in this study might be different if the

sleep monitoring device would be more interactive

and providing feedback.

Additionally, results could be different if the

study population would comprise of people who

experience sleeping problems or people who want to

improve their sleep. This implies, when choosing

people with sleeping problems as the study

population, that a motivation or goal is implicitly set

and feedback may be provided. These conditions

could be expected to produce different results

(Kazdin, 1974; Motl et al., 2012). As the wearable

monitoring devices evolve into accessible objects for

everyone, ignoring the reactivity of self-monitoring

could be a serious omission. As is mentioned earlier,

in this study some reactivity was observed, even

with the open setting of this study. In contrast, two

participants did not show any reactivity on each of

the measurements (wearable device or sleep diary).

5 CONCLUSIONS

This explorative study shows that when people -

who experience no sleeping problems - use an

unobtrusive sleep monitoring device, it barely has an

effect on a cognitive and behavioral level.

Conversely, reactivity effects were observed,

although unclear is what the cause is of these effects.

It is important to note that due to the explorative

character of this study no hard conclusion can be

drawn. However, this study shows that filling out a

sleep diary may be more intrusive than wearing a

sleep monitoring device. As a result, we are

DoesBeingMonitoredduringSleepAffectPeopleonaCognitiveandaBehavioralLevel?

currently running a study which investigates the

reactivity of filling out a sleep diary. Additionally,

this study demonstrates that there are many

unknowns about the effect of being monitored

during sleep and this is also true for the wearable

device in general. Whereas there has been

substantial research into the development of

wearable devices, there remains considerable scope

for research on the effect these devices may have on

people’s lives. It is important to know the reactive

outcomes of self-monitoring devices as the market

for these devices is rapidly growing and this may

have consequences for people who have a high

adherence to self-control. Moreover, a better insight

in the consequences of wearing such devices may

improve interventions carried out remotely by, for

example, sleep coaches.

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DoesBeingMonitoredduringSleepAffectPeopleonaCognitiveandaBehavioralLevel?