Graham Edgar

• Professor
• Professor at University of Gloucestershire

Emergency service vehicles may be called upon to stop where other drivers would not expect to encounter a stationary vehicle, and thus should be as conspicuous as possible. The most common pattern that is used to enhance the conspicuity of emergency (and other) vehicles is the, ‘inverted-V’ pattern on the rear of such vehicles. Given that this chev...

The investigation aimed to determine if Fire and Rescue Service (FRS) personnel display characteristic individual patterns of “bias” in decision-making during high-pressure simulated fire incidents. Research using the Quantitative Analysis of Situation Awareness (QASA) method revealed that despite expertise, FRS personnel display “bias” in how info...

Children will inevitably become members of space environments either as space natives or immigrants, facing potential developmental challenges in either case. Space communities may try to replicate terrestrial conditions and children may ultimately adapt to space conditions. Nevertheless, there may still be developmental hazards such as reduced gra...

The ‘human factor’ has long been recognised as one of the most significant factors underlying errors and accidents and is an area that needs further consideration for space programmes. As equipment becomes increasingly reliable, the humans operating it stay the same. Space environments will provide new and unusual challenges for all task components...

The Sustained Attention to Response Task (SART) is a go/no-go task where participants must respond frequently to target stimuli and withhold responses from infrequent neutral stimuli. Researchers have shown that the fast and frequent responding characteristic of SART is typically associated with difficulty withholding responses to no-go stimuli. Im...

This study examined quality of life (QoL) differences among diabetic patients in Nigeria by ethnicity, sex, and type of diabetes. Out-patients (n = 486) with diabetes mellitus (Type I = 16%; female = 71%; Igbo = 25% Hausa = 22%, Yoruba = 32%, other = 21%; mean age = 43.3 years, SD = 11.5 years) completed the World Health Organization Quality of Lif...

FireFront, an innovative digital tool for supporting training and self-awareness of decision-making to reduce risk in Fire and Rescue operations, is currently under trial in a new Erasmus Plus project. This tool is an important extension to its successful predecessor FireMind which featured in the November 2016 issue of International Fire Professio...

Cognitive resource limitations can impair one’s ability to multitask. Previous research has shown that climbing is a particularly demanding task, and does not neatly fit into existing cognitive resource models. Climbing is a task relevant to firefighting and search and rescue, and operators often must also handle communication and navigation tasks...

Objective: Two verbal tasks were utilized in a dual-task paradigm to explore performance theories and prior dual-tasking results. Background: Both the decline in vigilance performance over time, or vigilance decrement, and limited dual-tasking ability may be explained by limited mental resources. Resource theorists would recommend removing task...

Dual-tasking situations are common in military, firefighting, search and rescue, and other high risk operations. Cognitive and physical demands can occur at the same time, but little is known about the specific demands of real world tasks or how they might interfere with one another. It is well known that attempting simultaneous tasks will divide a...

This paper presents a model of situation awareness (SA) that emphasises that SA is necessarily built using a subset of available information. A technique (Quantitative Analysis of Situation Awareness – QASA), based around signal detection theory, has been developed from this model that provides separate measures of actual SA (ASA) and perceived SA...

In this study, we investigate whether emotionally engaged bottom-up processes of attention can be a source of ‘interference’ in situations where top-down control of attention is necessary. Participants were asked to monitor and report on a video of a war scenario showing a developing battle in two conditions: emotionally positive and emotionally ne...

Effective fireground decision-making requires good Situation Awareness (SA) and appropriate selection from the information available to the incident commander. Individuals can display different biases in their view of the operational incident: either a liberal bias towards accepting information as true and or a more conservative bias towards reject...

Attentional biases in anxiety disorders have been assessed primarily using three types of experiment: the emotional Stroop task, the probe-detection task, and variations of the visual search task. It is proposed that the inattentional blindness procedure has the ability to overcome limitations of these paradigms in regard to identifying the compone...

Purpose – The purpose of this paper is to assess whether firefighters display different decision- making biases: either a liberal bias to accepting information as true or a conservative bias to rejecting information, with the former carrying risk of “false alarm” errors and the latter of “misses”. Design/methodology/approach – Situation awareness (...

Decision-making forms a central component of the game of cricket. Due to the different formats of the game, players are often required to execute very different courses of action despite being presented with the same set of environmental cues (such as the type of delivery faced by a batter). This study sought to explore the degree to which the perc...

Effective performance in a situation relies on having a good awareness of that situation or at least, if SA is poor, being aware that this is the case. This study examined the bias (tendency to accept or reject available information) and actual and perceived SA of firefighters across two different situations The data suggested that, although actual...

The main issue of interest here is whether individuals who differ in arithmetical reasoning ability and levels of imagery ability display different brain activity during the conduct of mental arithmetical reasoning tasks. This was a case study of four participants who represented four extreme combinations of Maths – Imagery abilities: ie., low-low,...

The report takes a new approach to understanding how information is taken in and used on the fireground is being developed by staff from the Gloucestershire Fire and Rescue Service and CRACKLE (Centre for Research in Applied Cognition, Knowledge, Learning and Emotion) at the University of Gloucestershire. The research involves observing FRS teams d...

This paper investigated some effects of viewing a laser scanned display (LSD) on visual perception. LSDs potentially provide a high-brightness, monochromatic, image which could have particular effects on the visual system. As a monochromatic image may reduce a potential cue for visual accommodation (chromatic aberration), participants’ accommodatio...

This paper reviews the literature on factors that influence the visual (ocular) accommodation response when using see-through virtual image displays (VIDs) such as head-up and helmet-mounted displays. This review suggests that the overall accommodation response is determined by a complex interaction of many factors, some of which are associated wit...

This paper presents an original approach to measuring situation awareness that was invented and developed by the authors of this paper. This approach uses the well-established technique of signal detection theory to assess many aspects of SA, both within individuals and teams, and across a wide range of situations. There are however, many others ap...

This paper describes a technique for measuring situation awareness (SA) referred to as QUASATM (QUantitative Analysis of Situation Awareness). QUASATM uses the principles of signal detection theory to assess situation awareness. The technique is designed to provide objective measures of individual SA, dynamic SA and different components of SA. The...

Over-accommodation, a tendency to focus at a distance closer than the desired distance, has been previously shown to occur when using a head-up display (HUD). A simple system was developed as a warning of an inappropriate visual accommodative response (WIVAR) during flight training. Two lines, which are seen as four low-contrast lines (physiologica...

Whether over-accommodation is caused by the use of head-up displays is still under debate. Most prior experimentation has involved cognitively demanding tasks, which are known to affect the accommodation response. The simulations have often been unrealistic and involved short working distances. Over-accommodation is caused not by the presence of a...

A pilot study was conducted using functional magnetic resonance imaging (fMRI) techniques to assess changes in cortical activity while learning simple discriminations. The task was a simple visual description and it was found that activity in visual areas associated with performance of the task decreased as the task was learnt. Most interestingly,...

Car head-up displays (HUDs), which portray information in the form of a virtual image reflected off a combiner, allow the viewing of complex information, such as route guidance, without the need for the driver to look away from the road ahead. The cognitive demand required by the HUD task may distract drivers from the outside world scene and cause...

A study was conducted to examine the effect on the visual accommodation response of processing information presented either visually or aurally while viewing a real-world scene. A number of different conditions were tested in which a mental processing task, a virtual image overlaying the real world (as is the case with head-up displays), or both we...

Purpose: Car HUDs which, unlike those in aircraft, do not usually overlay the outside world, have been positioned in a variety of locations. With the likely increase of HUDs in cars, it is important to establish the optimum location to place the virtual HUD image. The effects of presenting the virtual HUD image to just one eye, or both eyes, while...

Perceived brightness is nonlinearly related to luminance. Consequently, any mechanism operating on the (transformed) luminance profile of a blurred edge to detect its location should make errors, and the magnitude of these errors should increase with contrast. The perceived location of a blurred edge was measured at a range of contrasts and a range...

The perceived blur of moving images is less than expected given the sluggish temporal response of the visual system. This suggests that a motion deblurring mechanism may exist to preserve the positional acuity and sharpness of moving images. Furthermore, when sequences of blurred stills are presented, observers report that the moving image is in sh...

Under certain conditions, multiple images trail behind a target moving across a cathode ray oscilloscope. Given the relatively sluggish temporal response of the visual system, it is surprising that when an image is rapidly displaced, multiple images are not seen under most circumstances. The authors have explored the conditions under which multiple...

Under certain conditions, multiple images trail behind a target moving across a cathode ray oscilloscope. Given the relatively sluggish temporal response of the visual system, it is surprising that when an image is rapidly displaced, multiple images are not seen under most circumstances. The authors have explored the conditions under which multiple...

Visual sensitivity to achromatic and chromatic stimulus flashes was determined at sites just inside, on the boundary and just outside scotomata in 11 patients with recovered optic neuritis. The colour of the flashes and the size of the steady background on which they appeared were such that detection was more likely to be mediated by either the lar...

Virtual-image displays are likely to become more prominent in the aircraft cockpit, the most common examples being the head-up display (HUD) and, more recently, the helmet-mounted display (HMD). There is, however, a possibility that when using such a display the eyes may be inappropriately accommodated (focused). A series of experiments have been c...

The prevailing view of motion detection in human vision is that the retinal image is convolved with each of a set of spatiotemporal filters and that perceived speed emerges from a process of pooling the outputs of these filters. Such a system can operate only if multiple filters exist; ideally the filters should also be fairly narrowly tuned in bot...

Visual function was studied in a group of 15 patients with hereditary motor and sensory neuropathy (HMSN). Psychophysical measures of luminance and chromatic threshold and temporal contrast sensitivity were undertaken, together with visual evoked potentials (VEPs), visual fields and clinical neuro-ophthalmological examination. A patchy loss of visu...

For pt.1 see ibid., p.3/1-3 (1992). The authors outline the nature of human factors (HF) research associated with the use of virtuality research (VR). While the previous paper addressed the issues of how best to represent the task from a cognitive perspective, here they focus upon the perceptual and interactive requirements that enable the human op...

Measurements of perceived speed were obtained for a variety of drifting simple and complex gratings, and measurements of perceived speed and direction were obtained for plaids. For sine gratings, perceived speed falls off at high spatial frequencies, the effect of spatial frequency being greatest at high speeds. Speed matches obtained from a variet...

McKee, Silverman and Nakayama (1986; Vision Research, 26, 609-619) have shown that velocity discrimination performance is little affected by quite large random changes in the spatial frequency, and hence temporal frequency, of the grating patterns to be discriminated. We show that the converse is also true: temporal frequency discrimination can be...

Visual function was investigated in a group of 58 clinically classified cases of multiple sclerosis (MS). Psychophysical measures of luminance and chromatic threshold sensitivity and temporal contrast sensitivity were undertaken, together with visual evoked potentials and Bjerrum screen perimetry. The patient group was divided on the basis of optic...

Temporal modulation sensitivity functions were measured centrally and at eccentricities of 2.5 degrees, 5 degrees and 10 degrees in the temporal visual field of 12 patients with recovered optic neuritis and in a group of matched normal controls. A circular, spatially uniform stimulus of 1 degree angular subtense was presented with sinusoidal modula...

Speed matching experiments were conducted using drifting gratings of different spatial frequencies in order to assess the influence of spatial frequency on perceived speed. It was found that gratings of high spatial frequency appear to drift more slowly than low spatial frequency gratings of the same actual velocity. The perceived temporal frequenc...

Measurements of the perceived spatial frequency of stationary sinewave gratings were made with the gratings presented at the same eccentricity in the left, right, upper, and lower visual hemifields. Ten subjects performed the task binocularly with spatial frequencies of 1, 2, and 4 cycles deg-1. Two of these subjects also performed the task monocul...

Thesis (Ph. D.)--University of Keele, 1988.