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ScienceDirect
Available online at www.sciencedirect.com
Procedia Computer Science 126 (2018) 1847–1854
1877-0509 © 2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of KES International.
10.1016/j.procs.2018.08.092
10.1016/j.procs.2018.08.092
© 2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of KES International.
1877-0509
Available online at www.sciencedirect.com
ScienceDirect
Procedia Computer Science 00 (2018) 000–000
www.elsevier.com/locate/procedia
1877-0509 © 2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of KES International.
22nd International Conference on Knowledge-Based and Intelligent Information &
Engineering Systems
A Pre-Analysis of the Effect of White, Blue and Green Background
Colours on Working Memory in a Reading Span Task
Muhammad Nur Adilin Mohd Anuardia
*
, Atsuko K. Yamazakia, Kaoru Etob
aShibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama, Japan
bNippon Institute of Technology, 4-1 Gakuendai, Miyashiro-cho, Minami Saitama-gun, Saitama, Japan
Abstract
Many studies have suggested that the design of a tablet screen can affect the performance its users. This study was conducted in
order to investigate whether different screen background colours can affect users’ brain functi ons when t hey are performing a
task on a tablet computer. The experiment focused on the relationship between background colours and memory span. Thirty
Japanese university students and seven elderly people participated in the experiment. A reading span task was used in the
experiment in order to observe the activities of the brain areas associated with working memory. The subjects were told to read
Japanese sentences aloud while memorising underlined words with three different background colours. The analysis results of the
performance scores for both young and elderly people showed that percentages were lowest for a white background compared
with other colours. Moreover, recorded near-infrared spectroscopy (NIRS) values were negative value, which indicated the
lowest activity in young people’s brains while performing the task with a white background. The results may suggest that a white
background might not a good choice for either performance or brain activity.
© 2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of KES International.
Keywords: background colour; working memory; brain function; NIRS; reading span task
* Corresponding author. Tel.: +08-48-687-5724; fax: +08-48-687-5013.
E-mail address: nb17106@shibaura-it.ac.jp
Available online at www.sciencedirect.com
ScienceDirect
Procedia Computer Science 00 (2018) 000–000
www.elsevier.com/locate/procedia
1877-0509 © 2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of KES International.
22nd International Conference on Knowledge-Based and Intelligent Information &
Engineering Systems
A Pre-Analysis of the Effect of White, Blue and Green Background
Colours on Working Memory in a Reading Span Task
Muhammad Nur Adilin Mohd Anuardia*, Atsuko K. Yamazakia, Kaoru Etob
aShibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama, Japan
bNippon Institute of Technology, 4-1 Gakuendai, Miyashiro-cho, Minami Saitama-gun, Saitama, Japan
Abstract
Many studies have suggested that the design of a tablet screen can affect the performance its users. This study was conducted in
order to investigate whether different screen background colours can affect users’ brain functi ons when t hey are performing a
task on a tablet computer. The experiment focused on the relationship between background colours and memory span. Thirty
Japanese university students and seven elderly people participated in the experiment. A reading span task was used in the
experiment in order to observe the activities of the brain areas associated with working memory. The subjects were told to read
Japanese sentences aloud while memorising underlined words with three different background colours. The analysis results of the
performance scores for both young and elderly people showed that percentages were lowest for a white background compared
with other colours. Moreover, recorded near-infrared spectroscopy (NIRS) values were negative value, which indicated the
lowest activity in young people’s brains while performing the task with a white background. The results may suggest that a white
background might not a good choice for either performance or brain activity.
© 2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of KES International.
Keywords: background colour; working memory; brain function; NIRS; reading span task
* Corresponding author. Tel.: +08-48-687-5724; fax: +08-48-687-5013.
E-mail address: nb17106@shibaura-it.ac.jp
1848 Muhammad Nur Adilin Mohd Anuardi et al. / Procedia Computer Science 126 (2018) 1847–1854
2 Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000
1. Introduction
Recently, tablet computers and smartphones have become essential tools in our daily lives. So many designs
have been created to meet the satisfaction and suitability of users. Due to their portability, efficiency, ease of use and
high speed, tablet computers are considered as an ideal tool for all generations, including the elderly and youngsters
1. Tablet computers are also used extensively to perform daily tasks more easily and to strengthen the brain’s
cognitive ability 2. Many studies suggest that the design of a tablet computer screen can affect the user’s attention,
concentration and performance 3. Some studies also have investigated combinations of text and background colours
used on a computer screen in relation to their effect on task performance 4, 5. A study of background colours
conducted by Mehta and Zhu indicated that task performance could be affected by background colours 6. Yamazaki
examined whether the background colours of computer- and web-based tests influenced the scores of test takers and
suggested that neurological factors associated with colour characteristics could affect the test score averages of
university students for different background colours 7.
The objective of this study was to investigate whether background colours could affect subjects’ performance
and brain functions while completing a task using tablet computers. In this study, the researchers investigated the
brain activities of subjects to observe differences in the brain areas associated with working memory and
concentration. Another focus of this study was to identify a suitable background colour that would enhance the
subjects’ cognitive ability and increase their performance when using the tablet. Previously, the author conducted
experiments on tasks with five different background colours on young and elderly subjects. In this study, the authors
focused on a reading span task to test the subjects’ brain functions with the top three colours compared with their
performance and brain activity in a previous experiment 8.
2. Experiment
The experiment was conducted to investigate the working memory of subjects’ brains while they a performed
task on a tablet computer with three different screen background colours: white, blue and green. Thirty young
subjects and seven elderly subjects participated in this experiment. In order to identify which part of the subjects’
brains were activated a reading span task was used. Subjects’ brain activity and relative changes in their blood
haemoglobin (Hb) concentrations in the brain were measured during the task using a near-infrared spectroscopy
(NIRS) system.
2.1 Reading span task with three background colours
For the experiment, three sets of the reading span task, each with black text and one of the background colours
were used. The three colours were chosen based on the best background colours in terms of task performance and
brain activity from a previous experiment 8. Each test set consisted of five levels of reading span task questions. The
first level of the reading span task started with two sentences, followed by three sentences for the second level and
six sentences for the last level, which made 20 sentences in total for each set. All of the question pages were
designed in the same way: sentences with one underlined word were presented in black on the single-colour
background of a tablet screen. These sentences would be shown one by one for each level. The reading span task
was used to test the subjects’ concentration level and working memory. They were told to memorise the underlined
words in the sentences while reading them aloud with each background colour. They were then required to recall the
underlined words and say them aloud. Thirty seconds of rest were allowed before continuing to the next level. All of
the task questions and designs were based on the original standard computerised version of the reading span task 9,
10. Figure 1 shows examples of the reading span task question pages for white, blue and green background colours,
respectively. A Lenovo Yoga 2 tablet computer, with a 10.1’ screen size (1920 × 1200 pixels), was used in the
experiment.
2.2 Subjects
Thirty native Japanese university students (27 males and three females, between the ages of 18 and 24 years)
and seven native elderly people (four males and three females, 65 years of age and older) participated in this study.
At the time of the experiment, none of them was reported to have any colour vision impairment. The subjects were
given instructions prior undertaking the task and none of them had trouble doing the task on the tablet computer
during the experiment.
Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000 3
2.3 Experimental method
All subjects performed the task with black text on three different arbitrarily selected background colours. The
characteristics of the three colours used in this experiment are listed in Table 1. To avoid systematic errors in the
scoring procedures, the background colours were presented randomly for each participant. This was also done to
conserve the contents of the task. The table summarises their hexadecimal colour codes, brightness and the colour
differences between the background colours and black foreground colour. Formulas suggested by the World Wide
Web Consortium (W3C) were used to calculate these values 11. A Lenovo Yoga 2 tablet computer, which had a
10.1’ screen size (1920 × 1200 pixels), was used in the experiment. The subjects were asked to memorise 20 words
for each background colour. The scores for each task were obtained and analysed to identify whether there were
differences between the test sets with the three background colours.
Table 1. Hexadecimal codes, brightness differences, colour differences, luminance ratios and luminance differences of three background colours
with black symbols
Background colour
Hexadecimal code
Brightness difference
Colour difference
Luminance ratio
Luminance difference
White
#FFFFFF
255
765
21
1
Blue
#0000FF
29
255
2.44
0.0722
Green
#00FF00
150
255
15.3
0.7152
Fig. 1. Example of reading span task question pages.
After finishing the task for each background colour, the subjects responded to a designed questionnaire in
Japanese to obtain their personal information and their feedback about the task. The questionnaire used a five-point
scale to inquire about the readability and difficulty of the test, and the subjects’ tiredness, colour preferences and
concentration levels during the test. Figure 2 shows the English translation of the designed questionnaire.
The relative changes in haemoglobin concentrations were measured and recorded using a 16-channel Hitachi
NIRS (WOT-100) while the subjects were performing the task. The NIRS probes covered their frontal regions, as
shown in Fig. 3. The relative changes in oxy-, deoxy- and total haemoglobin concentrations were recorded for each
subject.
[1] I felt tired from doing the task.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
[2] The task was difficult.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
[3] I could concentrate while doing the task.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
Muhammad Nur Adilin Mohd Anuardi et al. / Procedia Computer Science 126 (2018) 1847–1854 1849
2 Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000
1. Introduction
Recently, tablet computers and smartphones have become essential tools in our daily lives. So many designs
have been created to meet the satisfaction and suitability of users. Due to their portability, efficiency, ease of use and
high speed, tablet computers are considered as an ideal tool for all generations, including the elderly and youngsters
1. Tablet computers are also used extensively to perform daily tasks more easily and to strengthen the brain’s
cognitive ability 2. Many studies suggest that the design of a tablet computer screen can affect the user’s attention,
concentration and performance 3. Some studies also have investigated combinations of text and background colours
used on a computer screen in relation to their effect on task performance 4, 5. A study of background colours
conducted by Mehta and Zhu indicated that task performance could be affected by background colours 6. Yamazaki
examined whether the background colours of computer- and web-based tests influenced the scores of test takers and
suggested that neurological factors associated with colour characteristics could affect the test score averages of
university students for different background colours 7.
The objective of this study was to investigate whether background colours could affect subjects’ performance
and brain functions while completing a task using tablet computers. In this study, the researchers investigated the
brain activities of subjects to observe differences in the brain areas associated with working memory and
concentration. Another focus of this study was to identify a suitable background colour that would enhance the
subjects’ cognitive ability and increase their performance when using the tablet. Previously, the author conducted
experiments on tasks with five different background colours on young and elderly subjects. In this study, the authors
focused on a reading span task to test the subjects’ brain functions with the top three colours compared with their
performance and brain activity in a previous experiment 8.
2. Experiment
The experiment was conducted to investigate the working memory of subjects’ brains while they a performed
task on a tablet computer with three different screen background colours: white, blue and green. Thirty young
subjects and seven elderly subjects participated in this experiment. In order to identify which part of the subjects’
brains were activated a reading span task was used. Subjects’ brain activity and relative changes in their blood
haemoglobin (Hb) concentrations in the brain were measured during the task using a near-infrared spectroscopy
(NIRS) system.
2.1 Reading span task with three background colours
For the experiment, three sets of the reading span task, each with black text and one of the background colours
were used. The three colours were chosen based on the best background colours in terms of task performance and
brain activity from a previous experiment 8. Each test set consisted of five levels of reading span task questions. The
first level of the reading span task started with two sentences, followed by three sentences for the second level and
six sentences for the last level, which made 20 sentences in total for each set. All of the question pages were
designed in the same way: sentences with one underlined word were presented in black on the single-colour
background of a tablet screen. These sentences would be shown one by one for each level. The reading span task
was used to test the subjects’ concentration level and working memory. They were told to memorise the underlined
words in the sentences while reading them aloud with each background colour. They were then required to recall the
underlined words and say them aloud. Thirty seconds of rest were allowed before continuing to the next level. All of
the task questions and designs were based on the original standard computerised version of the reading span task 9,
10. Figure 1 shows examples of the reading span task question pages for white, blue and green background colours,
respectively. A Lenovo Yoga 2 tablet computer, with a 10.1’ screen size (1920 × 1200 pixels), was used in the
experiment.
2.2 Subjects
Thirty native Japanese university students (27 males and three females, between the ages of 18 and 24 years)
and seven native elderly people (four males and three females, 65 years of age and older) participated in this study.
At the time of the experiment, none of them was reported to have any colour vision impairment. The subjects were
given instructions prior undertaking the task and none of them had trouble doing the task on the tablet computer
during the experiment.
Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000 3
2.3 Experimental method
All subjects performed the task with black text on three different arbitrarily selected background colours. The
characteristics of the three colours used in this experiment are listed in Table 1. To avoid systematic errors in the
scoring procedures, the background colours were presented randomly for each participant. This was also done to
conserve the contents of the task. The table summarises their hexadecimal colour codes, brightness and the colour
differences between the background colours and black foreground colour. Formulas suggested by the World Wide
Web Consortium (W3C) were used to calculate these values 11. A Lenovo Yoga 2 tablet computer, which had a
10.1’ screen size (1920 × 1200 pixels), was used in the experiment. The subjects were asked to memorise 20 words
for each background colour. The scores for each task were obtained and analysed to identify whether there were
differences between the test sets with the three background colours.
Table 1. Hexadecimal codes, brightness differences, colour differences, luminance ratios and luminance differences of three background colours
with black symbols
Background colour
Hexadecimal code
Brightness difference
Colour difference
Luminance ratio
Luminance difference
White
#FFFFFF
255
765
21
1
Blue
#0000FF
29
255
2.44
0.0722
Green
#00FF00
150
255
15.3
0.7152
Fig. 1. Example of reading span task question pages.
After finishing the task for each background colour, the subjects responded to a designed questionnaire in
Japanese to obtain their personal information and their feedback about the task. The questionnaire used a five-point
scale to inquire about the readability and difficulty of the test, and the subjects’ tiredness, colour preferences and
concentration levels during the test. Figure 2 shows the English translation of the designed questionnaire.
The relative changes in haemoglobin concentrations were measured and recorded using a 16-channel Hitachi
NIRS (WOT-100) while the subjects were performing the task. The NIRS probes covered their frontal regions, as
shown in Fig. 3. The relative changes in oxy-, deoxy- and total haemoglobin concentrations were recorded for each
subject.
[1] I felt tired from doing the task.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
[2] The task was difficult.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
[3] I could concentrate while doing the task.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
1850 Muhammad Nur Adilin Mohd Anuardi et al. / Procedia Computer Science 126 (2018) 1847–1854
4 Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000
[4] The background screen of the task was
easy to see.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
[5] I liked the background screen colour of
the task.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
Fig. 2. English translation of questionnaire that subjects answered after completing the task.
(a) (b)
Fig. 3. (a) NIRS machine position on a subject’s head; (b) NIRS probes and channel mapping for the measurement.
3. Results
The reading span task scores for each subject were determined based on the total word recalls by the subject. A
total of 20 sentences consisted of 20 target words, which would make 20 the highest possible score for each set with
a given background colour. The average percentage scores of the reading span tasks answered correctly by both
young and elderly subjects for each background colour were calculated and are summarised in Fig. 4.
Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000 5
Fig. 4. Average percentage scores for reading span task.
For each background colour, the average percentages for the reading span tasks performed by both young and
elderly subjects showed slight differences. Both groups of subjects performed best with the green background colour
and worst with the white background. The authors conducted a variance analysis (ANOVA) to examine the
significance of differences between the background colours for the correct answers of the reading span task. Table 2
summarises the ANOVA analysis results for both groups.
Table 2. ANOVA analysis results for young and elderly subjects
Background colour
(Young)
Average
Variance
P(T ≤ t)
Background colour
(Elderly)
Average
Variance
P(T ≤ t)
White
15.8667
6.0506
0.7356
White
8.5714
8.619
0.5761
Blue
16.1
8.4379
Blue
9.5714
12.619
Green
16.2667
4.6851
Green
9.8571
15.1429
The ANOVA test result demonstrated that there was no significance difference for each background colour for
both young and elderly subjects. The authors then conducted a t-test (p < 0.05) for each background colour with a
white background, and found that there was no significance difference for the reading span task score between all of
the background colours versus a white background. Table 3 summarises the t-test analysis results for both groups.
Table 3. T-test analysis results for young and elderly subjects
Young
White
Blue
White
Green
Mean
15.8667
16.1
15.8667
16.2667
Variance
6.0506
8.4379
6.0506
4.6851
P-value
0.3197
0.1817
Elderly
White
Blue
White
Green
Mean
8.5714
9.5714
8.5714
9.8571
Variance
8.619
12.619
8.619
15.1429
P-value
0.1668
0.1643
The authors then observed the average NIRS signal value that was measured while the subjects were performing
the task. Figure 5 shows the average NIRS signal value for each background colour for young subjects only. The
average values for the three colours showed that for young subjects taking the reading span test, the frontal areas of
79.3 80.5 81.3
42.9
47.9 49.3
0
20
40
60
80
100
White Blue Green
Young Old
Muhammad Nur Adilin Mohd Anuardi et al. / Procedia Computer Science 126 (2018) 1847–1854 1851
4 Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000
[4] The background screen of the task was
easy to see.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
[5] I liked the background screen colour of
the task.
1. Strongly disagree
2. Disagree
3. Neutral
4. Agree
5. Strongly agree
Fig. 2. English translation of questionnaire that subjects answered after completing the task.
(a) (b)
Fig. 3. (a) NIRS machine position on a subject’s head; (b) NIRS probes and channel mapping for the measurement.
3. Results
The reading span task scores for each subject were determined based on the total word recalls by the subject. A
total of 20 sentences consisted of 20 target words, which would make 20 the highest possible score for each set with
a given background colour. The average percentage scores of the reading span tasks answered correctly by both
young and elderly subjects for each background colour were calculated and are summarised in Fig. 4.
Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000 5
Fig. 4. Average percentage scores for reading span task.
For each background colour, the average percentages for the reading span tasks performed by both young and
elderly subjects showed slight differences. Both groups of subjects performed best with the green background colour
and worst with the white background. The authors conducted a variance analysis (ANOVA) to examine the
significance of differences between the background colours for the correct answers of the reading span task. Table 2
summarises the ANOVA analysis results for both groups.
Table 2. ANOVA analysis results for young and elderly subjects
Background colour
(Young)
Average Variance P(T ≤ t)
Background colour
(Elderly)
Average Variance P(T ≤ t)
White
15.8667
6.0506
0.7356
White
8.5714
8.619
0.5761
Blue
16.1
8.4379
Blue
9.5714
12.619
Green
16.2667
4.6851
Green
9.8571
15.1429
The ANOVA test result demonstrated that there was no significance difference for each background colour for
both young and elderly subjects. The authors then conducted a t-test (p < 0.05) for each background colour with a
white background, and found that there was no significance difference for the reading span task score between all of
the background colours versus a white background. Table 3 summarises the t-test analysis results for both groups.
Table 3. T-test analysis results for young and elderly subjects
Young
White
Blue
White
Green
Mean
15.8667
16.1
15.8667
16.2667
Variance
6.0506
8.4379
6.0506
4.6851
P-value
0.3197
0.1817
Elderly
White
Blue
White
Green
Mean
8.5714
9.5714
8.5714
9.8571
Variance
8.619
12.619
8.619
15.1429
P-value
0.1668
0.1643
The authors then observed the average NIRS signal value that was measured while the subjects were performing
the task. Figure 5 shows the average NIRS signal value for each background colour for young subjects only. The
average values for the three colours showed that for young subjects taking the reading span test, the frontal areas of
79.3 80.5 81.3
42.9
47.9 49.3
0
20
40
60
80
100
White Blue Green
Young Old
1852 Muhammad Nur Adilin Mohd Anuardi et al. / Procedia Computer Science 126 (2018) 1847–1854
6 Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000
their brains were most active. Figure 5 demonstrates that a white background had the lowest average NIRS signal
value compared with other colours. The authors then observed the results of the questionnaire, which the young
subjects answered immediately after they finished the reading span task with each background colour. Figure 6
shows that the young subjects chose the white background as the least tiring and most preferable background colour
even though their performance score was lowest. Moreover, white was the easiest for them to see black fonts against
compared with blue and green backgrounds. However, young subjects could concentrate on the blue and green
background colours while doing the task.
Fig. 5. Average NIRS signal value for each background colour.
Fig. 6. Questionnaire results of young subjects on a five-point scale (1 = least, 5 = most).
-0.1
-0.05
0
0.05
0.1
0.15
0.2
White Blue Green
NIRS value
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Tiredness Difficu lty Con centration Visibility Favourable
White Blue Green
Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000 7
4. Discussion
This study focused on subjects’ task performance and brain activity. Therefore, their brain activity was analysed
while they performed the task with different background colours. The results demonstrated that a white background
showed the lowest scores in task performance compared with blue and green for both young and elderly subjects. A
comparison of young and elderly subjects’ results showed the same tendency in terms of task performance for each
background colour. However, owing to the deterioration of elderly subjects’ abilities, their task performance scores
were almost half those of the young subjects.
The frontal area of the brain is known to correspond to working memory. The NIRS values recorded during the
experiment demonstrated that young subjects’ brains had the lowest average NIRS signal when they performed the
task with a white background. From these values, young subjects’ brains showed the least activity while they
performed the reading span task with a white background compared with other background colours that showed
positive NIRS values. On the other hand, the young subjects answered a questionnaire and stated that a white
background was the best for visibility. As suggested by Hall and Hanna, the greater contrast ratios between the
background and font colours lead to better readability 12. Therefore, we suggested that a white background might not
be suitable for the reading span task because the results for both brain activity and performance score were
unfavourable.
The results of our study showed the same tendency as Yamazaki’s, which suggested that bluish background
colours had better performance score compared with a white background 3, 7. However, the results showed a
contradiction with the results from the previous study, which stated that a white background had the best score for
the reading span task 13. This is because the reading span task that was used in the previous experiment was
somewhat easier and did not show any differences between background colours, even for elderly subjects. This
study’s results demonstrated that young subjects’ brains were most active with the blue background colour. This is
support by Anna’s study, which states that blue light exposure leads to greater functional brain responses within the
prefrontal cortex during working memory task performance 14.
5. Conclusion
This study was conducted in order to investigate how the background colour affects subjects’ brain functions
while they performed a task on a tablet. The results demonstrated that the combination of a white background and
black text may not be ideal for task performance or brain activation. However, in the future, we need to analyse the
NIRS measurement results for elderly people in order to compare them with those of the young subjects. In addition,
the NIRS measurement results need to be analysed in detail in order to determine which channels were activated
during performance of the reading span task and to identify which brain region corresponded with the activated
channels. Thus, the most suitable background colour could then be determined because our brains need a certain
amount of stress in order to develop their functions. Furthermore, the working memory area could also be focused
on more in the future because working memory is responsible for the processing of new and already-stored
information. As a next step, the authors are planning to consider the hue, brightness and contrast of the background
colour and font. The number of subjects also needs to be increased, as brain functions are known to vary among
individuals.
Acknowledgements
This work was supported by JSPS KAKENHI Grant Number 16K01076. The authors would like to extend their
gratitude to the individuals who participated in this study.
References
[1] Jayroe T. J. and Wolfram D. (2012) “Internet Searching, Tablet Technology and Older Adults” Baltimore, MD, USA.
[2] Chan M. Y., Haber S., Drew L. M., and Park D. C. (2013) “Training Older Adults to Use Tablet Computers: Does It Enhance Cognitive
Muhammad Nur Adilin Mohd Anuardi et al. / Procedia Computer Science 126 (2018) 1847–1854 1853
6 Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000
their brains were most active. Figure 5 demonstrates that a white background had the lowest average NIRS signal
value compared with other colours. The authors then observed the results of the questionnaire, which the young
subjects answered immediately after they finished the reading span task with each background colour. Figure 6
shows that the young subjects chose the white background as the least tiring and most preferable background colour
even though their performance score was lowest. Moreover, white was the easiest for them to see black fonts against
compared with blue and green backgrounds. However, young subjects could concentrate on the blue and green
background colours while doing the task.
Fig. 5. Average NIRS signal value for each background colour.
Fig. 6. Questionnaire results of young subjects on a five-point scale (1 = least, 5 = most).
-0.1
-0.05
0
0.05
0.1
0.15
0.2
White Blue Green
NIRS value
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Tiredness Difficu lty Con centration Visibility Favourable
White Blue Green
Muhammad Nur Adilin Mohd Anuardi et al./ Procedia Computer Science 00 (2018) 000–000 7
4. Discussion
This study focused on subjects’ task performance and brain activity. Therefore, their brain activity was analysed
while they performed the task with different background colours. The results demonstrated that a white background
showed the lowest scores in task performance compared with blue and green for both young and elderly subjects. A
comparison of young and elderly subjects’ results showed the same tendency in terms of task performance for each
background colour. However, owing to the deterioration of elderly subjects’ abilities, their task performance scores
were almost half those of the young subjects.
The frontal area of the brain is known to correspond to working memory. The NIRS values recorded during the
experiment demonstrated that young subjects’ brains had the lowest average NIRS signal when they performed the
task with a white background. From these values, young subjects’ brains showed the least activity while they
performed the reading span task with a white background compared with other background colours that showed
positive NIRS values. On the other hand, the young subjects answered a questionnaire and stated that a white
background was the best for visibility. As suggested by Hall and Hanna, the greater contrast ratios between the
background and font colours lead to better readability 12. Therefore, we suggested that a white background might not
be suitable for the reading span task because the results for both brain activity and performance score were
unfavourable.
The results of our study showed the same tendency as Yamazaki’s, which suggested that bluish background
colours had better performance score compared with a white background 3, 7. However, the results showed a
contradiction with the results from the previous study, which stated that a white background had the best score for
the reading span task 13. This is because the reading span task that was used in the previous experiment was
somewhat easier and did not show any differences between background colours, even for elderly subjects. This
study’s results demonstrated that young subjects’ brains were most active with the blue background colour. This is
support by Anna’s study, which states that blue light exposure leads to greater functional brain responses within the
prefrontal cortex during working memory task performance 14.
5. Conclusion
This study was conducted in order to investigate how the background colour affects subjects’ brain functions
while they performed a task on a tablet. The results demonstrated that the combination of a white background and
black text may not be ideal for task performance or brain activation. However, in the future, we need to analyse the
NIRS measurement results for elderly people in order to compare them with those of the young subjects. In addition,
the NIRS measurement results need to be analysed in detail in order to determine which channels were activated
during performance of the reading span task and to identify which brain region corresponded with the activated
channels. Thus, the most suitable background colour could then be determined because our brains need a certain
amount of stress in order to develop their functions. Furthermore, the working memory area could also be focused
on more in the future because working memory is responsible for the processing of new and already-stored
information. As a next step, the authors are planning to consider the hue, brightness and contrast of the background
colour and font. The number of subjects also needs to be increased, as brain functions are known to vary among
individuals.
Acknowledgements
This work was supported by JSPS KAKENHI Grant Number 16K01076. The authors would like to extend their
gratitude to the individuals who participated in this study.
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