Negative Outcomes Brought by Poor Sleeping Quality concerning

Emotion, Reaction, and Memory

Yizhe Wang

Centre for Languages & International Education, University College London, London, U.K.

Keywords: Pittsburgh Sleeping Quality Index, Sleep Quality, Depression Index, Reaction Time, Short Term Memory,

College Students.

Abstract: The present study experimentally investigated the potential effects caused by low sleeping quality in emotion,

reaction speed, and memorizing ability among students over high school(mainly college students over 20 in

age). The method was to assign samples (N=34) into two groups according to their scores in the

PSQI(Pittsburgh Sleeping Quality Index), and they were asked to complete another depression index

questionnaire and tasks designed in the reaction and memorizing test. Measurements of their mood condition

and memorizing capacity were achieved by counting final scores, while reaction speed was quantitative by

calculating the total time spent finishing those tasks. The results obtained in this work showed that participants

who acquire higher sleeping quality(getting marks <5) tend to behave better in the memorizing test. However,

no obvious evidence is revealed that poor sleeping quality or sleeping deprivation(with marks =>5) is

responsible for longer reaction time and a more vulnerable mental state.

1 INTRODUCTION

1.1 Background

Before this study was conducted, some research about

existing conclusions on the role of sleeping in daily

routine, the association between sleeping quality and

depression, memorizing level, and reaction time were

conducted. Followings are results found in journal

articles, textbooks, and official reports.

1.1.1 Importance of Healthy Sleep

It is beyond dispute that sleeping is a crucial stage in

mammals' living routine. We humankind spend

approximately one-third time of our lives asleep.

Sleep is an essential biological function with

significant roles in recovery, energy conservation,

and survival. In rats, total sleep deprivation can cause

death within three weeks (Rechtschaffen et al. 1989).

In the dimension of neuroscience, one hypothesis

for sleep-related rhymes is that they help the brain

disconnect the cortex from sensory input. A night

filled with sleep in bed for up to 8 hours might allow

the body to recover from physical exertion, while a

negative mood would probably occur the next day if

enough sleep is not obtained (Bear et al. 2020).

Another hypothesis shows that metabolic wastes

during wakefulness are cleared from the brain during

sleep (Purves et al. 2018).

Sleep also appears to be essential for multiple vital

processes, such as brain development, learning,

memory, heart regulation, cellular detoxification, and

regulating emotional, cardiovascular, and metabolic

functions (Mukherjee et al. 2015).

For the psychologist, sleep functions to recognize

information received in the daytime under some

logic. Research discovers that compared with staying

awake, proper sleep could improve the ability to solve

problems significantly (Wagner et al. 2004).

Therefore, a good sleeping habit should play an

essential role in developing students' learning

abilities.

All those researches convince people that sleep is

closely linked to a human's ability to memorize and

recognize. Projects like how sleep routine affects

learning, memorizing, and emotion have attracted the

attention of scientists from different fields.

1.1.2 Concerning Situation

Currently, it has raised social concerns that sleep

disturbance spreads out gradually as a common

Wang, Y.

Negative Outcomes Brought by Poor Sleeping Quality Concerning Emotion, Reaction, and Memory.

DOI: 10.5220/0011248600003438

In Proceedings of the 1st International Conference on Health Big Data and Intelligent Healthcare (ICHIH 2022), pages 233-238

ISBN: 978-989-758-596-8

233

phenomenon among Chinese college students in the

wake of the accumulating study stress and diverse

ways of entertainment. One research where 112939

university students were included found that the

overall pooled prevalence of sleep disturbances was

25.7%, the percentages of students dissatisfied

with sleep quality and those suffering from insomnia

symptoms were 20.3% and 23.6%, respectively (Li et

al. 2018).

However, the evil sleep habits of Chinese young

people can date back to their experience in middle

school. Burdened with tons of homework, they were

always forced to work until midnight and wake up

early in the morning, leading to severe sleep

deprivation. Even worse, the prohibition of

entertainment can give rise to revenge consumption

of Internet games and addiction to virtual

competitions, which are to blame for sleep disorders.

Furthermore, the suicide rate has increased

constantly in recent years. 2.8% prevalence of suicide

attempts and more than 600,000 suicide attempters

among college students indicate that suicide attempt

among college students is a significant public health

problem in China (Yang et al. 2015).

1.2 Question and Exploration

Unfortunately, it is well recognized that sleep

disturbance is prevalent among adolescents,

especially those suffering from the population

suffering from mental disorders like depression. A

survey indicates that depressed adolescents usually

underwent longer sleep onset, had more wake after

sleep onset and had lower sleep efficiency than those

who were non-clinical or had relief (Lovato and

Gradisar 2014). However, their samples were mainly

adolescents ranging from 12-20 years, so the results

might differ from those drawn in this study.

As for the impact of sleep deprivation on memory

consolidation, how sleep quality can affect non-

declarative memory is hugely controversial; Giuditta

raised Dual-Process Hypothesis, that whether the

REM (Rapid Eye Movement)stage of NREM(non-

rapid eye movement)stage functions depends on

which kind of memory is formed (Giuditta 2014).

While Barrett insisted Sequential Hypothesis that the

alternation between REM-NREM plays a dominant

role in the efficiency of memory consolidation

(Barrett and Ekstrand 1972).

Therefore, this study will explore the effect of

sleep quality on the accuracy and reaction time of

declarative memory recognition with tasks including

remembering irregular number sequences, phrase

combination, and face recognition to investigate

whether two groups with different sleep qualities

would have discrepancies in performance.

2 GOAL AND HYPOTHESIS

2.1 Goals of This Study

This study was expected to demonstrate the adverse

effects of poor sleep quality on several aspects,

including those indicators relevant to learning ability

and depression or frustration. Besides the awareness

of the importance of healthy sleep, a solution is

expected to be introduced to improve the living

quality of college students.

2.2 Hypothesis

If college students over 20 frequently undergo poor

quality sleep in the last month, they are more

vulnerable to gloomy moods, react more slowly, and

harder to produce and store declarative memories.

3 METHODS AND

EXPERIMENTAL

PROCEDURES

3.1 Samples

The subjects were 40 Chinese college students with

their average age = 21.5±2.5, including 19 males and

21 females. Each participant received a package

containing detailed instructions, a PSQI survey, a

depression index survey, a reaction test, and a

memorizing test via e-mail, and they were asked to

respond to the mail with their answers attached, then

their scores were counted respectively. Finally, 34 of

them finished all of the materials, so 34 valid data

groups were collected.

All participants were selected from students

around researchers, had finished or undergoing higher

education. Each of them volunteered to participate in

this study that rewards of any means were not offered.

3.2 Materials

3.2.1 Sleep Quality Survey

In order to ensure participants' sleeping conditions,

they were asked to finish PSQI(Pittsburgh Sleep

Quality Index), which made it possible to recognize

ICHIH 2022 - International Conference on Health Big Data and Intelligent Healthcare

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their sleep habits and sleep quality in the last month.

This index was compiled by Professor Buysse et al.

from the University of Pittsburgh in 1989. In 1996,

the Chinese version was produced by Xianchen Liu et

al. The reliability and validity for the Chinese

population were also proved by their researches

involving ordinary people, patients diagnosed with

insomnia, depressive disorder, and schizophrenia. (α

value=0.84).

This index consists of 7 dimensions, including

subjective sleep quality, sleep latency, sleep duration,

sleep efficiency, sleep disturbance, use of sleep

medication, and daytime dysfunction (Buysse et al.

1989). The PSQI includes a scoring key for

calculating a patient's seven subscores, each of which

can range from 0 to 3. The subscores are tallied,

yielding a "global" score that can range from 0 to 21.

A global score of 5 or more indicates poor sleep

quality; the higher the score, the worse the quality

(Carole A, n.d.).

3.2.2 Depression Index

The mood survey tested participants’ moods.

Questions were asking their mood in the past couple

of weeks, their take on life. Furthermore, they asked

if they had been experiencing any physical changes.

The standard is as follows:

Depression Severity: 0-10 none, 11-21 mild, 22-

32 moderate, 33-43 moderately severe, 44-60severe.

3.2.3 Reaction Test

In this test, three parts of tasks were designed. The

first one is to find all allocated numbers in the

following sequence: all ten numbers with three

among 48 sequences. Moreover, the second one is to

find all Chinese characters with one shared structure

from all the characters shown on the screen. The final

task is graph recognition, for instance, to find all four

equilateral triangles from all assigned graphs. Once

the participants finished all the tasks, the time spent

would be measured.

3.2.4 Memory Test

Based on the Clinical Memory Scale(CMS) published

in 1986, a simplified version of the memory test was

constructed to improve the experimental procedure,

including three sections: association learning, random

number sequences recalling(instead of meaningless

graph recognition in CMS), and face-associated

features recognition (Xu and Wu 1986). In the first

part, in total, 18 pairs of Chinese phrases were shown

to participants. Half of them were connected

logically(e.g., apple-fruit in English), while the other

half were meaninglessly linked or even belonged to

different parts of speech(e.g., light-following).

Participants were given 20 seconds to memorize all

those combinations and would have 1 minute to fill

the blank with only one of the phrases were shown on

the screen. Such a kind task is repeated twice in the

first part in the same way but with different phrases

(eighteen sets of meaningful words and eighteen sets

of meaningless ones in total). For the second part,

participants were asked to remember random number

sequences within 1.5 seconds and write them

correctly in 3 seconds(eight sequences with seven

numbers, one sequence with five numbers, one with

six numbers, one with eight numbers, one with nine

numbers). The final task is to repeat the three lines of

personal information in 15 seconds after being shown

features connected with faces, including nationality,

occupation, and age, for 5 seconds. Three faces with

nine lines of features were arranged in one task, and

four tasks would be conducted in total(including

Western male and female faces & Eastern male and

female faces).

The followings are the scale for this test:

First section: Three scores were assigned for one

meaningful set, six scores for meaningless sets.

Second section: One score was assigned for the

sequence with five numbers, two scores for the

sequence with six numbers, three scores for

sequences with seven numbers, four scores for the

sequence with eight numbers, five scores for the

sequence with nine numbers.

Third section: One score was assigned for one

feature associated with an Eastern face and two for

those associated with a Western face.

With 252 scores in total, participants getting

scores higher than 110 would be considered to have

performed well, while those ending up 110 scores or

less would be judged as poor.

3.3 Tools

3.3.1

Document Retrieval

The digital database of document retrieval applied in

this paper includes Web of Science, PubMed, and

Google Scholar. The keywords researched includes

"sleep", "REM", "memory consolidation",

"depression", "reaction", "declarative memory" and

"Chinese student suicide rate".

Negative Outcomes Brought by Poor Sleeping Quality Concerning Emotion, Reaction, and Memory

235

3.3.2 Data Analysis

IBM SPSS statistics 23 was used in this study to

conduct correlation analysis.

4 RESULTS

4.1 Statistics

Table 1: Pearson Test.

Correlations

SleepingQualit

DepressionIndex reaction time MemorizingIndex

SleepingQuality Pearson

Correlation

1 .135 -.031 .374

Sig. (2-tailed)

.445 .863 .029

34 34 34 34

DepressionIndex Pearson

Correlation

.135 1 -.341

-.227

Sig. (2-tailed)

.445 .049 .197

34 34 34 34

reaction time Pearson

Correlation

-.031 -.341

1 .336

Sig. (2-tailed)

.863 .049 .052

34 34 34 34

MemorizingIndex Pearson

Correlation

.374

-.227 .336 1

Sig. (2-tailed)

.029 .197 .052

34 34 34 34

*. Correlation is significant at the 0.05 level (2-tailed).

Table 2: Regression Test.

Model Summary

Model R R Square

Adjusted R

Square

Std. The error

of the Estimate

Durbin-

Watson

.374

.140 .113 31.466 1.405

a. Predictors: (Constant), SleepingQuality

b. Dependent Variable: MemorizingIndex

Table 3: Coefficients.

Model

Unstandardized

Coefficients

Standardized

Coefficients

t Sig.

Collinearity Statistics

B Std. Error Beta Tolerance VIF

(Constant)

85.288 9.360

9.112 .000

SleepingQuality

4.903 2.149 .374 2.281 .029 1.000 1.000

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Figure 1 Normal Distribution Analysis.

4.2 Analysis

4.2.1

Pearson Test

Table 1 shows the result of the Pearson test.

According to the Pearson test, correlation is

significant if p-value <0.05. Unfortunately, no

significant correlation between sleep quality,

depression index, and reaction time were found.

Meanwhile, R-value can indicate the degree to which

two variables are associated. It is a value ranging from

-1 to 1. The greater its absolute value is, the stronger

correlation the two variables have. As for sleeping

quality and memory ability, the data indicated that

higher PSQI scores(poorer sleeping quality) could

lead to lower memory levels.

4.2.2

Regression Test

In order to explore the detailed connection between

sleeping quality and memory, linear regression

analysis was decided to be conducted with results

shown in Table 2 and Table 3. According to the R

square value, sleeping quality contributes to about

14% of memory scores, which is a dominant factor in

statistics. Table 3 suggests the value of constant and

coefficient, for which the equation involving memory

scores and sleeping index can even be deduced:

𝑀𝑒𝑚𝑜𝑟𝑦 𝐼𝑛𝑑𝑒𝑥  𝑆𝑙𝑒𝑒𝑝 𝐼𝑛𝑑𝑒𝑥 ∗ 4.903  85.288.

4.2.3

Test of Normality

Figure 1 shows the condition of the normal

distribution of the memorizing index data. The

condition of the distribution of the dots fits the line

closely, so the scores acquired are distributed

normally.

CONCLUSIONS

Three experiments were conducted in order to

discover the relationship between sleep quality and

three other variables. The result shows a positive

correlation between sleep quality and short-term

declarative memory storage(p value=0.029<0.05, R

value=0.374, two tail, Table 4.1.1.1). This result

testifies that people undergoing a healthy sleep the

last night tend to memorize tasks better. While there

is no significant correlation between sleep quality and

depression index or reaction speed. Because the p

values of them are 0.445 and 0.863, all bigger than

0.05. These statistics disprove the hypothesis,

meaning that better sleep quality results in better

emotional states or faster reactions. However, they

could be attributed to the limitations demonstrated

below.

LIMITATIONS

6.1 Samples

Due to the financial limitation, it was challenging to

offer rewards to participants in this study, for which

reason samples from classmates or friends closely

around were most available, which was likely to

cause convenient bias. For example, all of the

participants were experiencing or had finished higher

education. In addition, the sample amount was not

very broad(N=34), so fortuity could not be excluded.

Furthermore, the time delay was unavoidable through

internet interviews. An inaccurate time report could

be produced for this reason.

6.2 Materials

It is worth noticing that some of the surveys

mentioned above were self-designed. Although quite

a quantity of documents was referred to, there was no

evidence that all the materials applied could discover

the exact condition. Take the depression survey, for

instance. Inaccurate results could be achieved by a

Negative Outcomes Brought by Poor Sleeping Quality Concerning Emotion, Reaction, and Memory

237

survey limited to 9 questions.

6.3 Equipment

Although PSQI is widely recognized as an efficient

survey to release the sleep quality of participants, a

brain wave recorder is required if the research on the

sleep stage, brain wave features, and eye movement

features need to be conducted, which helps to confirm

the effect of different sleep stages on memory

formation.

7 FUTURE DIRECTIONS

7.1 Study Accuracy

In the future, the study is expected to be clarified in

three aspects. First, tests on more participants must be

conducted, which leads to more accurate data and

statistics analysis, and the correlation of sleep quality

and other variables can be confirmed. Second, applied

materials require upgrading to fit into different groups

of participants and rule out irrelevant variables like

nationality, gender, age, and family background.

Finally, the access to technological equipment to

finish the further study is wished to come true.

7.2 Study Function on Society

This study hopes that people could realize the critical

role healthy sleep plays in people’s daily routine. In

modern society, staying up late or sleeping disorders

have become ordinary phenomena. A revolution to

such a problem on the way of studying and working

is also expected. College students, especially, should

keep a good habit of sleeping.

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