RESOURCE THEORY VS. MINDLESS THEORY

Resource Theory and Mindless Theory represent two of the most prominent theories in the study of vigilance. A relatively more recent theory, namely Goal Habituation theory, has also attracted much attention in this field. This week’s post will examine these theories theories in detail, beginning with a summary of the main points of each theory and a comparative analysis of the key similarities and distinctions. As a departure from previous posts, this week’s post will not feature any in-depth summaries of the papers, but will instead reference them throughout this post for evidence and discussion. In the questions and comments section, we will then integrate this week’s readings with those of previous weeks by comparing the debates between mindless and resource theory with those discussed in previous weeks, specifically those concerning the key contributors to the vigilance decrement. After an examination of the competing theories, we will select the most compelling theory by referencing evidence from this week’s readings. Lastly, we will conclude with comments on links to neuroscience and possible future directions.

COMPETING THEORIES AND COMPARATIVE ANALYSIS

Resource Theory

The central tenet of resource theory is the contention that vigilance requires limited processing resources. As Helton and Russell (2011) and Ariga et. al.  (2011) elaborated in their papers, resource theory maintains that vigilance tasks require subjects to make continuous discriminations and thus deplete their mental and cognitive resources, resulting in a decline in their performance efficiency.  Notable supporters of resource theory include Parasurman and Warm, whose vigilance taxonomy and review of advances in vigilance research we discussed last week. Thus, advocates of resource theory espouse the view that the vigilance decrement is due to the decline in “available attention resources” and “cognitive resources available for information-processing” (Helton and Russell, 2011). The robustness of resource theory lies primarily in the abundance of supportive evidence coming from a variety of different experiments, from behavioral, to brain imaging, to mental workload studies, as Helton and Russell (2012) details in their paper. For instance, See et. al. showed objective increases in task difficulty was directly linked to greater lapses of sustained attention. Furthermore, declines in cerebral blood flow in areas of the brain associated with vigilance have also been shown to correspond with the vigilance decrement.  Ultimately, the resource theory posits that the vigilance decrement is a manifestation of the depletion of mental and cognitive resources throughout the course of a vigil.

Mindless Theory

In contrast to resource theory, mindless theory holds that the vigilance decrement arises from the subjects’ inattention or mindless. In short, the subjects demonstrate decreased attention to the vigilance task out of boredom. First described by Robertson and colleagues, the mindless theory states that subjects’ “supervisory attentional system loses effectiveness and ceases to focus awareness on the vigilance task” after a certain time of performing the same, repetitive task. As a result, subjects begin to respond to the task in a “thoughtless manner,” and acts out of routinization rather than attention (Ariga and Lleras, 2011). Since the Mindless Theory is relatively younger than Resource Theory, supportive evidence is slightly more limited. Much of the evidence for mindless theory comes from results of sustained attention to response task (SART) studies. Robertson et. al. (1996) describes this approach as well as its advantages over the conventional perceptual detection-based tests such as the Triplets test. Specifically, SART involves withholding of key presses in response to signals. The rationale behind this paradigm was the view that SART tasks require a “high level of continuous attention” and thus would test uniquely for sustained attention. Results confirmed this hypothesis and indicated that SART was sensitive to vigilance deficits and “predicts reported attentional failures in subjects.” Analysis of SART indices of attentional disengagement (measured through three variables, namely response time speed, anticipations, and omissions of signal responses) have shown a correlation between the vigilance decrement and the subject’s attentional disengagement, thus providing evidence for the mindless theory.

Goal Habituation Theory

The goal habituation theory, though similar to the Mindless Theory, has several important differences with the latter. Proposed by Ariga and Lleras (2011), this new theory attributes the vigilance decrement to the difficulty in maintaining an active goal for a “prolonged period of time.” Specifically, they argue that cognitive goals, such as maintaining attention through a vigilance task, also show habituation effects (described as the “eventual absence of representation of sustained stimulation”), and that it is this “goal habituation” that accounts for the decrement in vigilance tasks. In accordance with this theory, Ariga and Lleras argued “deactivating the vigilance goal would preempt full goal habituation by re-strengthening the goal’s activation,” and thus manifest in an enhancement in vigilance. Results indicated that the “mere prompt” of activating a different goal was sufficient to enhance vigilance, a finding that clearly supports the habituation hypothesis.

QUESTIONS AND COMMENTS

Blast From the Past: Parallels and Distinctions Between Current and Previous Debates

Examination of these competing theories brings to mind clear parallels of the debates we discussed in previous weeks on the key cause of the vigilance decrement. For instance, while signal detection theory held the background event rate responsible, Broadbent and Gregory attributed it to the decline in subject confidence. Upon a closer look, we find that the debate between resource, mindless, and goal habituation theories has clear echoes of the past debates. For instance, resource theory maintains the vigilance decrement is due to a depletion of mental resources, which is rather in line with Parasurman’s argument that memory load contributes to sensitivity decrements. To take this one step further, resource theory’s claim that cognitive and mental resources are depleted also echo See et. al.’s study on the necessity to examine the vigilance decrement in the context of the total task demands, in addition to memory load. Furthermore, the cognitive component addressed by resource theory is also in line with See et. al. and other researchers’ view that vigilance tasks require cognitive resources and that cognitive-based tasks may be different from perceptual-based tasks. Interestingly, however, while See et. al. saw a stabilization of performance and in some cases, a rise in performance, during cognitive tasks, resource theory does not take such observations into consideration. On another note, the Mindless Theory also falls in line with several of Scerbo (1998)’s findings. Specifically, the latter posited that boredom could have an effect in the vigilance decrement, which is clearly echoed in the Mindless Theory’s claims that the vigilance decrement arises out of inattention to the vigilance task. On a more “meta” level, I find the current debates and those that we discussed last week all share one similarity that may explain the existence of the debates: they all hypothesize that one factor or process is the key contributor to the vigilance decrement. However, as will be discussed in the section immediately following this one, the ideal theory should incorporate components of all the candidate theories.

Moment of Truth: Which Theory is Most Compelling (and Why)?

Okay, so here, I’m going to err…cheat a bit. I know we’re technically suppose to select one theory, but I don’t think there’s one theory that is clearly the winner. Moreover, I feel that quite possibly, the “correct theory,” is a mixture of all three theories. I believe the most compelling theory should have the evidence (and claims) of resource theory but also take into consideration the possibilities suggested by mindless and goal habituation theory. For something as complex as vigilance, I don’t think that any one variable or explanation could be the only correct explanation. To do so would be to neglect the complexity of the problem as well as that of the evidence. The key, at least in my opinion, is to recognize that the theories presented are not mutually exclusive. For me, the most compelling theory might look something like this: the depletion of mental and cognitive resources (which is proposed by resource theory) can be due to both mental fatigue and boredom, which may stem from goal habituation. While this is rudimentary, it takes into account many variables such as resource depletion and mental fatigue but also links together possible explanations into one compelling argument. Oh, and disclaimer: I’m not self-complimenting, really. Well, maybe just a tiny bit.

General Questions and Comments

            In this section, I would like to raise a general question that I have wondered about for a long time. It does not address this week’s papers specifically, per se, but this week’s assignment rekindled this question. I know the scientific method is the bible of science, and that everything begins with observation and a hypothesis. However, I feel that once we believe that something is true/i.e. have a hypothesis, we are almost certain to find evidence to support it. In short, it is possible to basically prove anything as long as we look for evidence in favor of our “hypothesis.” Yet, doesn’t this contribute to biased data and results? Aside from undermining the rigorous nature of science research, if this approach indeed biases our findings (and by virtue of being human, we all have preferences, etc.), and if that research is then used to produce clinically relevant products, isn’t this a significant problem? Clearly, I think the scientific method has significant merits. I’m just wondering about a possible flaw. I agree that most of this can be controlled by discipline, but sometimes, I feel that maybe starting out with no hypothesis but rather with the intention of studying something, may be more compelling. Just a thought though.

LINKS TO NEUROSCIENCE

I think it would be extremely interesting to examine the competing theories through the lens of neuroscience experiments. For resource theory, we would need to first define what constitutes “mental and cognitive resources.” We could begin by testing just a few variables such as memory and attention. We can then construct mouse models in which the mutant mice have impaired ability to process information or tire more quickly. If the resource theory is correct, then one would expect the mutant mice to demonstrate a quicker and more pronounced vigilance decrement than the wild type mice. A difficulty that has to be overcome is pinpoint the exact manipulation that would result in impaired information processing. One approach is legion of the hippocampus or frontal cortex. One could also use RNAi to silence genes that are known to be important in attention and information processing. For the mindless model, we can use human subjects. Specifically, we can use fMRI and transcranial brain imaging to see which areas of the brain are activated during repetitive and “boring” tasks, and most importantly, monitor the decline in activation intensity over the course of the vigil. To incorporate goal habituation theory, we can perform a similar procedure, but insert goal-changes sporadically. If the theory is correct, then one would expect to see in increase in activation of vigilance-related brain areas (every time a goal change is promoted) following a decline in those areas after a prolonged time.

REFERENCES

Robertson, I. H., T. Manly, et al. (1997). 'Oops!': performance correlates of everyday

attentional failures in traumatic brain injured and normal subjects. Neuropsychologia

35(6): 747-758.

Allan Cheyne, J., G. J. Solman, et al. (2009). Anatomy of an error: a bidirectional state

model of task engagement/disengagement and attention-related errors. Cognition

111(1): 98-113.

Helton, W. S. and P. N. Russell (2011). Feature absence-presence and two theories of

lapses of sustained attention. Psychol Res 75(5): 384-392.

Ariga, A. and Lleras, A. (2011). Brief and rare mental ‘‘breaks’’ keep you focused:

deactivation and reactivation of task goals preempt vigilance decrements. Cognition

118:439–443.

Helton, W. S., & Russell, P. N. (2012). Brief mental breaks and content-free cues may not

keep you focused. Experimental Brain Research, 219, 34–46.

Image References:

Graduate Studies in Neuroscience (Msc/PhD) http://www.uleth.ca/artsci/neuroscience/graduate-studies-neuroscience-mscphd. (Accessed 13/02/2013).

Eco-Cinema and Film Genre. The Land Before Time and Evolutionary Narratives. http://ecocinema.blogspot.com/2012/06/land-before-time-and-evolutionary.html. Accessed 13/02/2013)

Parasuraman Vigilance Taxonomy

The “vigilance decrement” is one of the most consistent findings in studies and experiments on vigilance. First articulated by Mackworth in 1948, this decrement describes the marked reduction in performance observed in (correct) signal detection as a function of time. Several theories, such as signal detection theory, have arisen to explain this decrement, and by the late 1970s, two primary factors emerged as key players in this vigilance decrement: sensitivity to the presented signals (d’) and response criteria (beta). In short, some groups attributed this decrement to a possible decrease in perceptual sensitivity as a function of time while others (such as Broadbent and Gregory, 1965) reported subjects’ decrease in confidence as a key cause. While researchers agreed that both parameters were important, the relative and dynamic contributions of each factor remained inconclusive. Many questions still remained. Was the vigilance decrement caused by different factors in different types of studies? Was it the same in auditory vigilance tasks? Are perceptual sensitivity and response criterion both involved in vigilance decrements across all studies? Enter Parasuraman Vigilance Taxonomy.

First described by Raja Parasuraman in 1979, Parasuraman Vigilance Taxonomy (PVT, as it will be referred to henceforth) provides a framework upon which to characterize the vigilance decrement as a function of the type of task. Specifically, it divides tasks into two groups: those that loads memory and those that don’t. PVT holds that different factors are responsible for the vigilance decrement in these two different types of tasks. In this post, we explore the Parasuraman Vigilance Taxonomy in detail by first providing a comprehensive description of it and then citing evidence in support of the taxonomy. Although most of the evidence presented in the papers for today are in favor of the PVT, it is still extremely important to consider the contrary evidence, and this is exactly what we will do. On a deeper level, we will perform a comparative analysis in which we examine proposed revisions to PVT, such as additions of new dimensions, in particular the sensory-cognitive distinction described by See et. al. Furthermore, We will also examine the strengths and weaknesses of the taxonomy. Subsequently, we will perform a deeper analysis of the studies performed and raise questions concerning the experimental design and result interpretation. Lastly, we conclude with PVT’s links to neuroscience and possible future directions.

DESCRIPTION OF PVT: WHAT IS IT?

            The Parasuraman Vigilance Taxonomy refers to a framework for distinguishing between the contribution of perceptual sensitivity and response criteria in the vigilance decrement. Specifically, as Raja Parasuraman detailed in his 1979 paper, this taxonomy holds that the vigilance decrement results from a decrease in perceptual sensitivity only during tasks that loads memory and have rapid event rates. Thus, tasks such as these, termed successive-discrimination tasks by Parasuraman, require the subject to compare the presented signal with previous signals represented in memory when they make a decision. As such, they require the subject to remember the intensity of previous signals in order to make a comparison, and thus impose a type of cognitive load on the subject. In the second type of task, termed simultaneous discrimination by Parasuraman, refers to tasks in which the signal and background events are presented together. Here, the subject is asked to discriminate between the signal and non-signal without needing to remember previous signals and non-signals. As such, these tasks do not load memory. According to PVT, the vigilance decrement in simultaneous discrimination tasks results from changes in the subject’s response criteria.

EVIDENCE: SUPPORATIVE AND OTHERWISE; POSSIBLE REVISIONS TO PVT

Much evidence exists to support the Parasuraman Vigilance Taxonomy. Here, we review three studies that investigated this topic (Parasuraman, 1979; See et. al., 1995; Warm et. al., 2008), with particular focus on their experimental design, results, and how these results provide evidence in favor of the Parasuraman Taxonomy. Since most of the later commentary will concern the Parasuraman paper, we will provide an in-depth review of his methods and results and a brief overview of the other papers, which will be included in the comparative analysis section.

Summary of Parasuraman, 1979

Methods and Experimental Design:          Subjects were asked to perform two types of tasks: successive-discrimination and simultaneous-discrimination tasks (defined above). In the first experiment, subjects performed an auditory vigilance task. In the successive-discrimination group, subjects were asked to distinguish between an intermittent 1000Hz tone (non-signal) and a periodic 2.1-dB increase in that tone (the signal). On the other hand, subjects in the simultaneous-discrimination group were asked to detect a 1000-Hz tone within an intermittent noise burst. Low and high event rates (15 events/min and 30 events/min, respectively) were tested for each group and conditional target probability was controlled for during each task. In a second experiment, three visual vigilance tasks at a high event rate were compared. In the successive-discrimination condition, the signal was a decrease in the intensity of a flashing light. In the simultaneous-discrimination condition, two sources of light were present, and the signal was defined as a decrease in intensity in one of the light sources. A second simultaneous discrimination task defined the target as a small circle appearing at the center of one of the two light sources.

Results/Evidence:     In the first (auditory) experiment, Parasuraman found different results for the successive-discrimination and simultaneous-discrimination groups. Specifically, subjects in the successive-discrimination group exhibited a “progressive reduction in detection ability in consecutive time blocks” at high event rate, as indicated by receiver operating characteristic plots of the data. This reduction was absent during the low event rate. For the simultaneous-discrimination group, however, the data points clustered around a line of fixed detectability for both the low and high event rates, a result that indicated that the vigilance decrement observed in this condition was not due to changes in signal detectability. These results on decreases in performance in high-event rate successive-discrimination tasks (which load memory) suggest that perceptual sensitivity contributes to the vigilance decrement in tasks that load memory and occur at high event rates, a postulate of the Parasuraman taxonomy. Furthermore, the finding that event rate has no impact in simultaneous-discrimination tasks suggest that the vigilance decrement in these tasks could be attributed to response criterion, another tenant of the Parasuraman taxonomy.

COMPARATIVE ANALYSIS: Proposed Revisions and Advancing Vigilance Research

            The authors for this week all addressed the PVT in their studies; however, they had different approaches and conclusions. Here, we perform a comparative analysis of their findings and inferences. We begin with an examination of the proposed revisions by See et. al. and then explore the suggestions for advancing vigilance research posed by Warm et. al.

            See and his research group performed a meta-analysis of 42 vigilance studies in their effort to refine the PVT by identifying other task parameters that may contribute to the sensitivity decrement. Although this investigation provided evidence for Parasuraman’s finding that the decrement is substantial and is dependent on the type of discrimination and event rate, it also suggested revisions to the existing PVT. In particular, See et. al. found that vigilance studies should distinguish between sensory and cognitive tasks. Here, we will examine See et. al.’s study, with a particular focus on how their results support and question the original PVT. Lastly, we look at the proposed revisions proposed in the paper.

            Although much evidence exists to support the PVT, See notes that “additional investigation have indicated that the model may require refinement.” For one, the sensitivity decrement predicted by the model does not always occur in high-event rate/successive-discrimination tasks. Secondly, sensitivity decrements have been observed in cases (such as high-event-rate/simultaneous-discrimination tasks) where no such decrement should occur as predicted by the model. Even more pressingly, studies have shown that a sensitivity decrement can occur even in the absence of a memory load. This evidence to the contrary prompted See and other researchers to wonder whether the sensitivity decrement is caused by the total task demand rather than one or two aspects of the task. In particular, following the study by Koelega et. al., See investigated the distinction between sensory and cognitive vigilance tasks. In sensory tasks, the signal is a change in the physical attributes of the background event, whereas cognitive tasks utilize symbolic or alphanumeric events and signals. Ultimately, See et. al. found cognitive vigilance tasks were associated with a “vigilance increment,” a term coined to describe the stabilization in subjects’ performance as a function of time. This is in direct contrast to the results of sensory vigilance tasks reported previously. Thus, on the basis of these results, See et. al. suggests that the PVT needs to be refined to incorporate the distinction between cognitive and sensory tasks.

            Warm and colleagues discuss the developments and advances in vigilance research and argue that evidence from behavioral, subjective, and neural studies support the conclusion that vigilance requires mental work and is stressful, in accordance with attentional resource theory. Warm et. al. cites studies that support the PVT proposed by Parasuraman. Specifically, he notes that a number of studies have shown that successive tasks require more mental attentional resources, such as memory, than simultaneous-discrimination tasks. Indeed, he found that factors known to increase information-processing demand had a more drastic effect on performance on successive tasks than on simultaneous tasks, a result that supports the assertion that successive tasks are more resource demanding. However, Warm and colleagues also address the criticisms posed against resource theory. Specifically, the fact that the resources, as well as the increases in resource demands, are usually inferred from performance rather than measured (a phenomenon seen in the Parasuraman paper) is a striking flaw. In response to this criticism, Warm discusses studies that take the experimental procedures of Parasuraman and see one step further to incorporate neuroimaging techniques such as PET and fMRI. Studies such as these demonstrated increased cerebral blood flow in areas of the prefrontal cortex could serve as proxies to quantify attentional resources and mental workload. Furthermore, neuroimaging techniques such as transcranial Doppler sonography (TCD) have shown that the vigilance decrement is associated with a decline in blood flow velocity. Furthermore, the decline of blood flow was directly correlated to task demands, especially in the right cerebral hemisphere. The addition of this neural component provides greater insight into the processes underlying the vigilance decrement.

QUESTIONS AND COMMENTS

           Reading these three papers left me with several questions and comments on their approach, results, and inferences. Here, we will first consider the strengths and weaknesses of the Parasuraman Vigilance Taxonomy, as described by Parasuraman in his 1979 paper, and then address some further questions on this paper. We conclude with some comments on the results and inferences of See et. al. and Warm et. al.

Strengths and Weaknesses

The Parasuraman Vigilance Taxonomy has several prominent strengths, but also has several important flaws. Here, we examine the key strengths and weaknesses of this taxonomy.

Strengths:           The greatest strength of the Parasuraman Vigilance Taxonomy, in my opinion, is the fact that it provides a basis upon which the vigilance decrement could be understood and characterized. While no platform is perfect, the PVT gives researchers something concrete to worth with and expand upon. Furthermore, it takes into account that different types of vigilance tasks impose different demands on the subject, and thus may lead to a vigilance decrement for different reasons. The insight of PVT—that the same observed vigilance decrement may actually be due to different reasons—is a difficult and rare feat and serves as one of its key strengths. Furthermore, the fact that PVT is mostly supported by a variety of vigilance tasks—from auditory to visual—provides an additional pillar of strength of this taxonomy. Last week, I questioned why the vigilance tasks utilized were confined to visual tasks and whether other types of vigilance tasks (such as auditory tasks) would produce different results. The congruence in the results of the auditory and visual tasks, and in particular, the fact that PVT takes into consideration different types of vigilance tasks, is an important strength.

Weaknesses:         While the PVT has several key strengths, it also has important weaknesses. The most striking flaw for me was its disagreement with some empirical data, as reported by Parasuraman himself in later papers. For instance, Parasuraman found no sensitivity decrement in 5 of the 19 high-event-rate/successive-discrimination tasks; since these tasks clearly load memory, this result is in direct contrast to the Parasuraman Vigilance Taxonomy. Furthermore, the presence of a sensitivity decrement in vigilance tasks where no such decrement is predicted by the model (simultaneous-discrimination/high-event-rate tasks) also violates the taxonomy. The clear presence of empirical data that disagree with the taxonomy is concerning; even more pressing, however, is the possibility that these data points were not given the adequate consideration during the formation of the Parasuraman Vigilance Taxonomy. If PVT was formed on the grounds of biased data (where the limited number of data points that did not agree with the taxonomy were thrown out or given less attention), then this would serve as the greatest flaw of the taxonomy. Another weakness of the taxonomy is its binary nature. Specifically, it considers only two factors that may potentially affect the vigilance decrement; event rate and type of discrimination. Although this consideration is already a milestone in the study of vigilance, it does not take into account other factors of the study that may affect the vigilance decrement. Addition parameters such as overall task load, as suggested by See et. al., could contribute to the vigilance decrement. Furthermore, the original PVT does not take into consideration possible cases where both sensitivity decrement and response criterion are involved in the vigilance decrement. Although most of the prior research has suggested that these two factors may operate independently, it is still worthwhile to consider the interplay between these two factors as well as other parameters in contributing to the vigilance decrement.

Further Comments on Parasuraman, 1979

            The Parasuraman paper is clearly a groundbreaking achievement in the study of vigilance, and I found the paper extremely interesting. I did have some questions, however, about the inferences made from the results. For one, I found the attribution of the sensitivity decrement to memory load rather abrupt. While no one contests the fact that higher event rates during a successive-discrimination task would load memory more than a low-event one, there can also be alternative contributions to the sensitivity decrement. Yet, not such alternative contributions are even explored. Furthermore, no definitive experiment was done to prove the assumption that memory-load was the key difference between high-event-rate/successive-discrimination tasks and other tasks. Combined with the empirical data that disagreed with the model, this challenged the PVT for me. I would have liked to see more experiments establishing the link between event-rate and memory load.

See et. al. and Warm et. al.

            The researchers in these two studies addressed some of the inadequacies of the original PVT and made important progress. For instance, See et. al. addressed some of the inconsistencies of the PVT with experimental data and echoed the question whether there exist other contributions to the sensitivity decrement. While See et. al. makes an important revision to the original PVT by pointing out the difference between cognitive and sensory tasks, it also falls prey to the semi-binary inference-making seen in the Parasuraman paper. While their results illustrate a clear difference between cognitive and sensory vigilance tasks, they fail to take into account the interplay between these two factors. What about tasks that incorporate both cognitive and sensory elements? Do these two parameters operate independently or do they interact to produce the sensitivity decrement?

            I found the Warm paper extremely fascinating. For one, it is one of the first papers so far on the study of vigilance that incorporates a neural component and thus provides more definitive to support their results. Most compellingly, it discusses techniques that allow researchers to truly quantify the factors involved in the vigilance decrement. With neuroimaging and similar techniques, researchers studying vigilance can stop making inferences based on performance and actually measure factors of interest in this decrement. However, as painful as it is to say, even neuroimaging and neuroscience techniques have its limits. It will be interesting to observe and contribute to the advances in neuro-technology that may ultimately transcend the present limitations.

LINKS TO NEUROSCIENCE AND FUTURE DIRECTIONS

           I think Warm and colleagues have the correct idea in incorporating evidence and results from a variety of studies, including neural, behavioral, and subjective. I would be interested to further explore the neurobiological underpinnings of the vigilance decrement in the future, with a particular emphasis on the differences in the neurobiological process between successive-discrimination and simultaneous-discrimination tasks. Specifically, I think it would be interesting to have a “mouse model” of this phenomenon. A possible (and rudimentary) experimental design could be as follows. Since LTP, or long-term potentiation, is the cellular correlate of long-term memory formation, to investigate the role that memory load plays in the sensitivity decrement, we can impair early stage LTP or the working memory of mice and then measure their performance on successive-discrimination and simultaneous-discrimination tasks. If memory load is indeed the determining factor, then the mice with impaired LTP should demonstrate a greater performance decrement in the successive-discrimination trails than the simultaneous trails. Clearly, there are difficulties that must be overcome to perform an experiment like this. Mice need to be trained to perform the difference vigilance trails, and most importantly, humane treatment of the mice MUST be ensured.

Disclaimer: Okay, from working with mice, I know lab mice don’t actually look like that, but who can resist sleeping mice with a teddy bear or a mouse on a swing?

REFERENCES

Parasuraman, R. (1979). Memory Load and Event Rate Control Sensitivity Decrements in Sustained Attention. Science, 205, 924-927.

See, J.E., Howe, S.R., Warm, J.S., & Dember, W.N. (1995). Meta-Analysis of the Sensitivity Decrement in Vigilance. Psychological Bulletin, 117, 230-249.

Warm, J.S. and Parasuraman, R., et. al. (2008). Vigilance Requires Hard Mental Work and Is Stressful. Human Factors. 50(3): 433-441.

Image References

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