Critical evaluation of the paper: The role of working memory in supporting drivers’ situation awareness for surrounding traffic.
In the last few decades there has been an increasingly large amount of empirical research conducted on the relationship between working memory, such as, the visuo-spatial sketchpad, phonological loop and the central executive, on situation awareness (Groeger, 2000; Endsley, 2003). Situation awareness refers to the phenomenon by people have the ability understand factors in the environment so as to perform everyday tasks in an almost automatic fashion through the use of working memory (Caserta & Abrams, 2007). More recent research has been conducted by Johannsdottir and Herdman (2010), who investigated the influence of working memory on drivers’ situation awareness for surrounding traffic. The authors of this study argued that they had supported and expanded our knowledge of this subject (Johannsdottir & Herdman, 2010), but to what extent is this actually the case? This paper will present a critical evaluation of the paper “The role of working memory in supporting drivers situation awareness for surrounding traffic” (Johannsdottir & Herdman, 2010) with reference to further evidence from this subject.
The aim of the article “The role of working memory in supporting drivers situation awareness for surrounding traffic” (Johannsdottir & Herdman, 2010) was to investigate the role of working memory in relation to explaining its function in supporting drivers’ situation awareness for surrounding traffic. In order to investigate this role, the authors conducted two experiments using a driving simulator and different load tasks, such as, visuospatial-load, phonological-load and baseline tasks, wherein the participants would have to accurately identify where traffic was around their car through a frontal or rear view. It was found that visuospatial coding influences situation awareness for traffic from a frontal view and that phonological coding influences situation awareness for surrounding traffic from a rear view (Johannsdottir & Herdman, 2010). However, the extent to which this is the case will now be discussed in relation to the strengths and weaknesses of the study.
On face value the introduction of Johannsdottir and Herdman 92010) seems strong, as there is reference to the complexity of driving, working memory, and working memory and situation awareness. On the other hand, though working memory is explained in detail, a failure of the article under evaluation in this paper is that fails to make reference to the specific regions of the brain that are responsible for working memory, such as, the frontal cortex (Groeger, 2000; Canfield, 2006), which would add further detail and give the reader a better understanding of working memory, though this is perhaps not entirely relevant for such a study. Regardless of the relevance, this demonstrates that there is a lack of detailed information in relation to working memory even though the authors attempt to discuss this function in detail in the introduction.
In a similar sense, the introduction is also lacking a more detailed description of situation awareness. For example, Groeger (2000) highlighted the fact that there had been very little empirical research conducted in order to facilitate our understanding of the influence of the visuospatial sketchpad and the phonological loop on driving behaviour and situation awareness. Hence, this may help explain the lack of a more detailed explanation of the visuospatial sketchpad, the phonological loop and situation awareness presented in the introduction of Johannsdottir and Herdman’s (2010) article. On the other hand, there have been a series of studies following Groeger’s (2000) book that gives a more detailed description of these factors, particularly situation awareness, which is the least well explained in the article by Johannsdottir and Herdman. For example, Salmon et. al. (2006) give a detailed account of situation awareness that also refers to the problems of a universal description and model for this phenomenon. Furthermore, the article by Salmon et. al. refers to other models of situation awareness, such as, the perceptual cycle model by Smith and Hancock (1995, as cited by Salmon et. al., 2006, p.228) or the activity theory model by Bedny and Meister (1999, as cited by Salmon et. al., 2006, p.228) in contrast to Johannsdottir and Herdman, who base their study on Endsley’s (1995, as cited by Johannsdottir & Herdman, 2010, p.4) three level model of situation awareness without reference to any other model of situation awareness. Consequently, it could be argued that that the study by Johannsdottir and Herdman fails to take into account all explanations of situation awareness, which would give the reader a greater understanding of this subject. Conversely, it could be counter-argued that if the authors had presented more than one model for situation awareness, this may have confused the readers’ understanding of the study. However, this study may be low in validity and explanatory power.
In an article by Kass, Cole and Legan (2008), the visuospatial sketchpad is explained in detail, as it is in the article being evaluated in this paper, however, these authors focus on the influence of distractions, such as, through the use of mobile phones, which produces an attentional conflict in the coding of information in the working memory that results in driver performance or conversation deterioration. In light of this, Kass, Cole and Legan explain the conflict that occurs in the visuospatial sketchpad that results in this deterioration in relation to attention and distraction. In contrast, Johannsdottir and Herdman (2010) make little reference to attentional processes, which brings into question the explanations provided in their article and the explanatory power of their study.
The rationale of the study by Johannsdottir and Herdman (2010) clearly sets out the aims and objectives of the research. What is more, the authors make clear links to the possible role that the visuospatial sketchpad and the phonological loop has on situation awareness and driving by referring to Baddeley et. al. (2001, as cited by Johannsdottir & Herdman, 2010, p.665). Conversely, a problem with the introduction is that the experimental hypotheses are discussed in the individual experiment sections, which detracts from the rationale, reduces the flow of the article and can confuse the reader. Thus, the strength of the rationale is limited.
Following this, the descriptions of the two experiments and the methods and procedure for each experiment are presented. It is certainly the case that the experiments are discussed in detail, though, experiment 2 appears to lack any reference to the improvements made on the first experiment, which would reduce the possibility of another researcher conducting the improved experiment. Thus, the external reliability of the study is questionable.
In addition to this, there are many aspects of the vehicle, surroundings and vehicle feedback that influence situation awareness and driver performance (Walker, Stantion & Young, 2007). The study by Johannsdottir and Herdman (2010) fails to take into account much of these aspects, though, in experiment 2 auditory stimulation was also presented to the participants, which may have reduced the ecological validity and internal reliability of this study, as the simulation was limited and may have seemed artificial to the participants, resulting in their responses being less than natural. It may have been the case that the driving simulator produced vehicle feedback and many of the other aspects associated with driving but there was no reference to this in the article and so we have to assume that it was lacking. As such, an improvement of this study would be to present a more detailed description of the driving simulator and ensure that the driving experience from this simulator matched real life driving.
This study also fails to take into account the influence of age, focusing solely on individuals between 18-50 years, whereas age-related declines can help explain incidence of accidents (Caserta & Abrams, 2007). What is more, this study fails to take into account how enhancement of situation awareness can help older people continue to live everyday lives (Caserta & Abrams, 2007), such as, being able to drive. It may be unfair to criticise a study for such a failure when the researchers wished to focus on normal functioning, but a more representative sample of people should be used in order to produce a more holistic understanding the role of working memory on drivers’ situation awareness for surrounding traffic.
On the other hand, Bellet et. al. (2009) argue that there is need for better controlled experimentation and experimental procedures within this subject area so as to allow for better reproduction and replication of empirical studies. It is certainly the case that the two experiments conducted by Johannsdottir and Herdman (2010) were highly standardised and controlled, particularly in light of the replication study seen by the use of the second experiment, which indicates that this study was both high in internal and external reliability. What is more, due to the fact that the experiments were explained in such detail that it follows the assertions of Bellet et. al. and allows for replication to occur easily.
Moving on, the presentation of the statistical results for both experiments was poor, particularly in light of the statistical analysis used for these experiments, which was a 2 X 3 repeated-measures ANOVA. The reporting of the analysis was poor due to the fact that the authors failed to include the p values for the main effects and presentation of effect sizes would have been useful so as to give the reader a greater understanding of the results of the study. Without reporting the p values of the analysis, it is difficult for the reader to know whether the results were significant or not, and the reader has to rely on the assertions of the authors with regards to the significance, which brings into question the strength and significance of the results.
On a similar note, the presentation of the results in the form of graphs is useful to a certain extent to demonstrate the difference between visuospatial, phonological and baseline results, though Figure 2 (Johannsdottir & Herdman, 2010, p.670) may be more useful in showing the difference than Figure 1 (Johannsdottir & Herdman, 2010, p.668). When compared together, these figures do demonstrate the differences in result between the two experiments and thus it could be argued that these figures are important in helping the reader understand the difference between the experiments. However, it could be argued that in the case of experiment 1, a table would have been a more appropriate form of presentation for the results, as the figure does very little in helping explain the differences between the three conditions.
On these lines, the authors conclude that the visuospatial sketchpad and the phonological loops play important roles in supporting drivers’ situation awareness for surrounding traffic, but due to the problems with the presentation of the results, this argument seems weak, though sensible from what is presented. An improvement of this study would be to present the results in a more standardised and open manner so as to allow for a stronger concluding argument to be made.
The abstract for Johannsdottir and Herdman (2010) makes reference to the real world applications of the findings of this study, such as, providing better technologies to assist drivers. However, in the discussion of the study, the authors fail to discuss the real world applications of an understanding of work memory and situation awareness. Hence, the usefulness of this study is brought into question.
In addition to this, Groeger (2000) argued that verbal reasoning requires both the phonological loop and the central executive in order to function effectively, thus suggesting the fundamental need for the central executive in this form of behaviour. In addition to this, the findings of Baddeley (1968) and Groeger, Hammond and Field (1999, as cited by Groeger, 2000, p.111) indicates that an important role is played by the central executive when performing behaviour in demanding situations. The article by Johannsdottir and Herdman (2010) does make a series references to the role of the central executive, explaining the role this function plays in facilitating working memory in supporting drivers’ situation awareness for surrounding traffic. However, it is the case that this article fails to reiterate the importance of the central executive in the working memory and refers mainly to the visuospatial sketchpad and the phonological loop with suggestions for future directions for research focusing on the central executive. As such, it can certainly be argued that the explanatory power of this article for explaining working memory in supporting drivers’ situation awareness for surrounding traffic is useful for giving an overview of all related systems but is limited due to the fact that more emphasis is required to be placed on the function of the central executive.
In conclusion, the article “The role of working memory in supporting drivers situation awareness for surrounding traffic” (Johannsdottir & Herdman, 2010) aimed to investigate the role of working memory in relation to explaining its function in supporting drivers’ situation awareness for surrounding traffic, and to a certain extent this study reached its objectives. Furthermore, this study has helped support and further expands our understanding of situation awareness for drivers’ awareness of surrounding traffic. However, there are methodological weaknesses and limitations to the explanations presented in this paper that brings into question the validity and explanatory power of this study. As such, it can be argued that there are serious failings to this article and there is certainly much needed room for improvement if this study was to be useful. Future research in this area of study should endeavour to improve upon the problems of this study so as to be able to better explain the role of working memory in supporting drivers’ situation awareness for surrounding traffic, and provide better means through which road traffic accidents can be prevented in the future.
References:
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Bellet, T., Bailly-Asuni, B., Mayenobe, P. & Banet, A. (2009). A theoretical and methodological framework for studying and modelling drivers’ mental representations. Safety Science, 47(9): 1205-1221.
Canfield, J. G. (2006). Functional Evidence for Visuospatial Coding in the Mauthner Neuron. Brain, Behavior and Evolution, 67(4): 188-202.
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Endsley, M. R. (2003). Situation Awareness: Progress and Directions. In, S. Banbury. & S. Tremblay. (Eds). A Cognitive Approach to Situation Awareness: Theory and Application. Hampshire: Ashgate Publishing Limited.
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Walker, G. H., Stanton, N. A. & Young, M. S. (2007). What’s happened to car design? An exploratory study into the effect of 15 years of progress in driver’s situation awareness. International Journal of Vehicle Design, 45(1-2): 266-282.