Abstract
The use of different colours and contrast of text with their respective background can have a significant effect on the way people recall context, whether it is provided electronically or through print. Previous studies on the effect colour and contrasts can have towards recalling information, suggests that there are specific colours that can have an influence on memory performance; (e.g. individuals who viewed text against a high contrast red background perform better on a memory test compared to those who viewed text against a high contrast blue background). Furthermore, this research analyses word recall through different colours of text (black/green) against either a high contrast blue background or a low contrast blue background.
Introduction
Colours play an influential role in a person’s visual perception, which can also impact an individual’s ability to absorb information. Psychologists have found great interest in studying the effects that different hues can have to influence an individual’s performance in different cognitive tasks. Studies have shown that the use of primary colours (red, green and blue) enhance cognitive performance compared to shades of black and white (Mehta, & Zhu, 2009).
Colours can be altered through focal adjustments and manipulated through various levels of contrasts. These modifications place just as an important influence towards an individual’s visual perception, due to the neurological pathway that a visual stimulus passes through, affecting our cognitive ability to recall information. Visual information is more effectively retained through exposure context expressed by luminance or an intense change of colour (Cornelissen, & Greenlee, 2000). This can be explained by our photoreceptor signals which, when triggered by light intensity or high contrast of colour, can have a rapid effect on neurotransmitter release.
The view that light intensity can influence our ability to store memories, can be explained by the process of visual transduction (Dzulkifli, & Mustafar, 2013). Visual transduction occurs when high contrasted visual stimuli are converted into neural impulses via electrical signals in our eye. These signals are then translated into stimulating our cognitive reasoning. Our cognitive reasoning can help explain our ability to recall and absorb information.
Contrary to the influence colours and contrasts individually have towards visual memory. Very few studies have researched the effect of these two factors as a collective. Presuming the association of coloured text upon a contrasting background colour were of very similar hue. The use of high contrast associated with a bright text is visually challenging for individuals despite studies proving better task performance using these variables. Presenting this visual stimulus could deem more difficult to process and straining towards the human retina.
The stimulus that are interpreted as visual storage, can be discovered within specific regions of the brain, such as the superior anterior cingulate cortex. This superior anterior cingulate cortex is part of our limbic system, which includes our ability to learn, process and remember information. In relation to the context of this research, the presence of a high contrasted visual stimulus can influence our ability to store information.
Therefore, it is possible to assume that participants will perform better with recalling words situated conditions with black text associated with a high contrast background or bright text associated with a low contrast background in comparison to bright text associated with a high contrast background or black text associated to a low contrast background.
Method
Design
A two-way between-subjects’ ANOVA was used to test the influence of colour and contrast to the number of words recalled. There were two trials over two conditions; trial one of the first condition involved viewing a list of words in black coloured text over a high contrast blue background, trial two of the first condition displayed the same list of words but with green coloured text over the same high contrasted blue background, trial one of the second condition displayed the same list of words with black coloured text and a low contrast blue background, and lastly, trial two of the second condition displayed the same list of words with green coloured text over a low contrast blue background.
Participants
Participants were 40 healthy, undergraduate students (21 females, 19 males; mean age 20.93 [±S.D. 2.29]) from the University of Westminster, recruited through opportunity sampling. Participants were randomly allocated to one of the trials from either condition, placing 10 participants in each condition.
Materials
The conditions were presented electronically through a shared access document through google drive as well as an additional arithmetic task. Each condition and the arithmetic task was on a separate document and was shown on either an IPad, laptop or computer. The conditions contained 15 words (See Appendix.) which were all the same throughout each condition but presented with different coloured text with either a high contrast blue background or a low contrast blue background. Participants were also provided with a sheet of paper and a pen during the experiment which they could write down the number of words recalled.
Procedure
40 participants were gathered through opportunity sampling across different universities within London. Each participant was randomly assigned to one of two trials within one of two conditions; trial 1 within condition 1=black coloured text with a high contrast blue background, trial 2 within condition 1=green coloured text with a high contrast blue background, trial 1 within condition 2=black coloured text with a low contrast blue background and lastly, trial 2 within condition 2=green coloured text with a low contrast blue background.
All four conditions contained the same list of 15 neutral words (See Appendix.) which were displayed on either a computer/laptop/IPad on the same set of brightness to ensure reliability throughout the experiment. Participants assigned to their respective conditions were asked to remember as many words as they possibly could within a one minute time frame. After the one minute period, participants were then assigned an arithmetic task (See Appendix.) which was also the same across all trials over both conditions with which participants were given 1 minute to attempt. Lastly, participants were provided with a sheet of paper and a pen and asked to note down as many words from the first task as they could recall. Scores were then recorded and collated through a google drive document (See Appendix.)
Ethics
Participants were asked to sign a consent form (See Appendix.) before the experiment took place which outlined the estimated duration of the experiment as well as the topic of research. Participants were also given the right to withdraw before they took part in the experiment. At the end of the experiment, participants were handed a debrief form (See Appendix.) which assured that their data would be kept confidential as well as the main purpose of the research, outlining our hypothesis and additional background research in relation to our experiment.
Results
The data gathered was measured by a number of words recalled on trial 1 and 2 within the high contrasted first condition and trial 1 and 2 within the low contrasted second condition. Mean (±S.D.) are shown in Table 1, which shows little effect of colour and contrast to an individual’s ability to recall the context.
Table 1. Mean (±S.D.) recall scores with different colours and contrast
Contrast
Colour
Black text
Green text
High contrast blue
6.90(2.38)
7.80(2.90)
Low contrast blue
8.90(2.64)
7.30(1.57)
A two-way between-subjects ANOVA shows no main effect for the contrast of background, F(3, 1)=.957, p=.334, where participants viewed text on either a high contrast blue background or a low contrast blue background. There was also no main effect for the colour of text, F(3, 1)=.209, p=.651, with which participants viewed text with either black font or green font.
Discussion
Although the use of colours and adjustments of contrast have a separate effect towards an individual’s ability to recall information, findings from this study show that the combined use of colour with contrast has a very little effect towards word recall. The study conducted using a two-way between-subjects’ ANOVA, shows no main effect for word recall between both trials over both conditions; black text on high contrast blue, green text on high contrast blue, black text on low contrast blue, green text on low contrast blue. The results specified, therefore, accepts the null hypotheses that there is an effect between colour and contrast on word recall. However, there is no significant main effect between either colour or contrast in all trials towards word recall.
Replicating this research could further show significant main effects through manipulating the materials used as part of the method. The colour of green text used in both trial 2 in condition 1 and trial 2 in condition 2, would be intensified to a lighter gradient of green, to immerse with the high contrast blue background in trial 2 in condition 1 or be clearer on top of the low contrast blue background. The same could also be stated for the contrasting colours. The low contrast blue background used in both trial 1 in condition 2 and trial 2 in condition 2 can be contrasted to a darker hue to challenge participant’s ability to read and recall the context in trial 1 in condition 2 or stand out more beneath the bright green text in trial 2 in condition 2.
Researching the use of colour and contrast manipulation towards an individual ability to recall and retain information, can be effective towards real-life uses. Ways in which information is presented can have a significant impact towards the level of information preservation. For example, studies have shown that children starting from primary level up until secondary level perform better when viewing information on bright attractive colours compared to black text on the plain white background. This information can help the approach educational settings take, when teaching students as it could be a factor that helps individuals learn effectively.
The use of an arithmetic task helps strengthen the validity of the study. Viewing and attempting to solve an arithmetic task in between learning words and recalling them again epitomises daily interferences that individuals experience that can have a significant effect towards their short-term memory. To ensure face validity, the experiment could further be replicated through a different design. Studying word recall between different contrasts and colours, each participant can partake in two conditions each using a repeated measures design. Each participant can recall black text on a low contrast background then recall a different set of neutral words with black text on a high contrast background, both followed by a distraction task. These results can then be compared alongside each other and eliminate individual differences as a confounding variable.
On the other hand, the arithmetic that served as a priming effect towards participants’ ability to recall the given list of words, could also produce confounding variables. Participants were provided with the arithmetic task to complete in one minute, and this can serve as a stressor, given the time strain and level of difficulty to solve all arithmetic equations. In replicating this research, the arithmetic task can be replaced by another source to serve as a priming effect, such as an article containing unrelated words and sentences or even a set of images. These alternatives serve better as a priming variable as it requires little cognitive reasoning.
Overall, although the results are inconclusive to the given hypothesis that material presented through dark text on high contrast or bright text on low contrast, is more effective practices in recalling information, there are adjustments that can be manipulated towards the methodology of researching the effectiveness of colour and contrast, that can further explore more effective means of retaining information.