Optimal characteristics of inserted graphic objects in stimulating CCTV operator vigilance and performance

Ph.D. Faculty of Humanities, University of the Witwatersrand, 2011Vigilance is a key process fundamental for sustained performance in many jobs and in particular those requiring continual detection in visually intensive tasks. This research examined operators’ overall vigilance performance levels and decrements over time in the context of closed circuit television (CCTV) surveillance. The aims of the research were to develop an intervention to enhance the detection of significant events, and to establish the levels of overall vigilance performance and decrements in a CCTV surveillance task. The intervention consisted of electronically inserting graphic objects (IGOs) or images into the video stream with the intention of assisting operators in detecting actual significant events. IGOs could potentially represent an infinite range of visual stimuli, but it was argued that only particular visual characteristics are likely to enhance the detection of real significant events, rather than merely facilitating the detection of the IGOs themselves. In addition, the characteristics of IGOs are likely to influence the extent to which their relationship to significant events is understood. The research identified a range of characteristics that could be incorporated into IGO design, and focused on salience and semantic distance for the empirical part of the research. A matched three-group quasi-experimental design involved a sample consisting of 29 specialised CCTV surveillance operators, 13 control room operators doing surveillance, and 31 novices. The task consisted of observing a ninety-minute CCTV video showing general and target behaviour in a video stream of actual work settings. The control group received no IGOs, one treatment group received generic IGOs, and the second treatment group received IGOs with close semantic distances to target behaviours. There were indications that the IGOs had positive effects on alertness and attention sets, but this did not translate into statistically significant improvements in detection rates. Reasons for this included IGO characteristics, the complex and dynamic nature of CCTV displays and significant events, and the dynamic and spatiotemporal properties of the IGOs. Semantic distance was confirmed as an important IGO characteristic. The research demonstrated a number of critical insights into vigilance dynamics and visual processing and highlighted that there are gaps in the understanding of the attention processes that occur in jobs requiring sustained attention. Only half the target behaviours were detected despite all target behaviours being visible, indicating a concerning underperformance in intensive visual detection tasks involving complex work situations. Responses to vigilance demands were highly individualised, with decrements and surges beginning at different times across individuals. Qualitative analyses of participants’ behaviour also found fluctuations in task engagement, suggesting that sustained attention is unstable. Results did not support a steady, linear vigilance decrement for all sub-samples. An increment in detection rates was found for specialised participants after 60 minutes, while novices to surveillance tasks showed a more linear decrement. Work exposure was an important variable that contributed to detection levels and performance fluctuations over time. The research highlights differences between tasks with simple visual stimuli frequently used in vigilance research versus complex real-world tasks in vigilance intensive jobs. Important insights regarding vigilance processes in complex real-world jobs emerged, including the need for active searching processes, visual analysis, high levels of situation awareness and the importance of operator’s frame of reference and approach to the detection task. The research has likely implications for other visual imaging technologies such as x-rays, infrared and thermal imaging, and technology using newer millimetre wave and terahertz based imaging common in security, policing, and defence

See no Evil: Challenges of security surveillance and monitoring

While the development of intelligent technologies in security surveillance can augment human capabilities, they do not replace the role of the operator entirely; as such, when developing surveillance support it is critical that limitations to the cognitive system are taken into account. The current article reviews the cognitive challenges associated with the task of a CCTV operator: visual search and cognitive/perceptual overload, attentional failures, vulnerability to distraction, and decision-making in a dynamically evolving environment. While not directly applied to surveillance issues, we suggest that the NSEEV (noticing – salience, effort, expectancy, value) model of attention could provide a useful theoretical basis for understanding the challenges faced in detection and monitoring tasks. Having identified cognitive limitations of the human operator, this review sets out a research agenda for further understanding the cognitive functioning related to surveillance, and highlights the need to consider the human element at the design stage when developing technological solutions to security surveillance

Work experiences of CCTV surveillance operators.

The present research focused on the work experiences of CCTV operators. The rationale for this study was due to the fact that there has been a dearth of research regarding the ‘human element’ behind the actual operation of the CCTV surveillance system. Consequently, the aim of this study was to investigate the job design and characteristics of CCTV operators, and the factors perceived to influence job satisfaction and employee engagement. The design of this study was qualitative in nature and semi-structured interviews were conducted with ten CCTV operators who monitor cameras in shopping malls. The findings indicated that there are various activities that CCTV operators engage in, however, monitoring the cameras is the main activity. Other factors contributing to the operators’ job satisfaction and employee engagement was the relationships with supervisors, managers, co-workers and interactions with the public. In addition autonomy, fairness with regards to pay and hours, high workload, their own safety as well as the fact that their work has a significant impact on the lives of others were all found to add to their job satisfaction and employee engagement

Spontaneous facial expression analysis using optical flow

© 2017 IEEE. Investigation of emotions manifested through facial expressions has valuable applications in predictive behavioural studies. This has piqued interest towards developing intelligent visual surveillance using facial expression analysis coupled with Closed Circuit Television (CCTV). However, a facial recognition program tailored to evaluating facial behaviour for forensic and security purposes can be met if patterns of emotions in general can be detected. The present study assesses whether emotional expression derived from frontal or profile views of the face can be used to determine differences between three emotions: Amusement, Sadness and Fear using the optical flow technique. Analysis was in the form of emotion maps constructed from feature vectors obtained from using the Lucas-Kanade implementation of optical flow. These feature vectors were selected as inputs for classification. It was anticipated that the findings would assist in improving the optical flow algorithm for feature extraction. However, further data analyses are necessary to confirm if different types of emotion can be identified clearly using optical flow or other such techniques

Identification from CCTV: Assessing police super-recogniser ability to spot faces in a crowd and susceptibility to change blindness

Police worldwide regularly review CCTV evidence in investigations. This research found London police experts who work in a full-time ‘Super-Recogniser Unit’ and front line police identifiers regularly making suspect identifications from CCTV, possessed superior unfamiliar face recognition ability, and, with higher levels of confidence, outperformed controls at locating actors in a bespoke Spot the Face in a Crowd Test (SFCT). Police were also less susceptible to change blindness errors, and possessed higher levels of conscientiousness, and lower levels of neuroticism and openness. Controls who took part in SFCT actor familiarisation training outperformed untrained controls, suggesting this exercise might enhance identification of persons of interest in real investigations. This research supports an accumulating body of evidence demonstrating that international police forces may benefit from deploying officers with superior face recognition ability to roles such as CCTV review, as these officers may be the most likely to identify persons of interest

Inside our heads: an investigation into visual analysis and detection using the EEG

A research project submitted in partial fulfilment of the requirements for the degree of MA by coursework and Research Report in the field of Organisational Psychology in the Faculty of Humanities, University of the Witwatersrand, JohannesburgThe aim of this research is to examine the neurological processes involved in visual analysis tasks in terms of networks within the brain. It aims to examine these processes while considering the antecedents of visual analysis skills; specifically concentration spans, properties of the target, and signal detection characteristics such as the hit rate and reaction time. It posited that detection is positively associated with neural activity. A Pseudo quasi-experimental, cross sectional, within subject’s design that utilises a quantitative method of investigation was undertaken in order to determine whether this postulation held any merit. The study involved the participation of 8 volunteer students; each participant completed a demographic questionnaire as well as the New General Self-Efficacy Scale. They then underwent EEG recording while completing a 30 minute visual analysis task – ScanX. Results drawn from this research indicate that there is some association between neural activity and detection within the Alpha 1 and Theta frequency band. Time on task results in decreased neural activity in the Alpha 1, Alpha 2 and Beta 1 frequency band. False alarms had no significant associations with neural activity; yet neural activity indicated an association with misses. Self-efficacy was assessed in terms of reaction time and this yielded no significant result. Limitations, as well as theoretical and practical implications, of this study are considered. Finally, the study suggests further possible lines of research that could elaborate on the relationship between detection and neural activity

A Study of Semantic Processing Performance

Examining the role of individual differences, especially variations in human motivation, in vigilance tasks will result in a better understanding of sustained semantic attention and processing, which has, to date, received limited study in the literature (see Fraulini, Hancock, Neigel, Claypoole, & Szalma, 2017; Epling, Russell, & Helton, 2016; Thomson et al., 2016). This present study seeks to understand how individual differences in intrinsic motivation affect performance in a short semantic vigilance task. Performance across two conditions (lure vs. standard condition) were compared in the present study of 79 undergraduate students at the University of Central Florida. The results indicated significant main effects of intrinsic motivation on pre- and post-task stress factors, workload, and performance measures, which included correct detections, false alarms, and response time. Sensitivity and response bias, which are indices of signal detection theory, were also examined in the present study. Intrinsic motivation influenced sensitivity, but not response bias, which was affected by period on watch. The theoretical and practical implications of this research are also discussed

The normalisation of 'excessive' workforce drug testing?

In 'The normalization of 'sensible' recreational drug use' Parker, Williams and Aldridge (2002) present data on illegal drug use by adolescents and young adults in the UK. They argue that it is both widespread and largely socially benign - ie, normal. We contrast this 'normalisation' thesis with evidence of an increase in the introduction of drug policies -- and drug testing -- in British organisations. Such policies construct employee drug use as excessive enough to necessitate heightened management vigilance over workers, in order to preserve corporate interests. These contrasting representations of drug use inspire our discussion. We deploy the normal/ excessive couplet to unpick drug taking, to examine organisational drug policies and to comment upon emerging and potential resistance to these policies. Our contribution is to suggest that each of these activities can be understood as simultaneously normal and excessive, in an area where orthodox and critical analyses alike tend to be far more dualistic

How can we use realist evaluation to better inform research into alcohol-related assaults in night-time economies? A case study using CCTV

The problem of alcohol-related assaults (ARAs) in night-time economy (NTE) precincts is an ongoing issue of policy concern and research interest. One punch truly can kill. This thesis examines the feasibility of a multi-agency linking method to more accurately count these kinds of assaults in close to real-time in order to inform suitable responses by Queensland liquor accords. This can provide more timely evidence to evaluate interventions. This thesis was the first Australian research to achieve this. The Cairns Hospital Emergency Department, the Queensland Police Service and the Cairns Regional Council Closed Circuit Television (CCTV) system are capable of providing relevant data regularly. Venues can provide relevant data but capacity to do so regularly is limited. Results support previous research regarding prevalence and time of occurrence of NTE ARAs. The thesis also uses Realist Evaluation to examine how an urban, open-space CCTV system responds to, and reduces, these NTE ARAs. The realist evaluation approach explains why quasi-experimental studies have found CCTV has no effect on this type of offence, but practitioners see CCTV as vital. The thesis shows why the theory of deterrence through CCTV does not apply to NTE ARAs. Conflicting empirical results regarding the efficacy of CCTV in broader crime reduction are explained. A case study analysis of CCTV to address NTE ARAs identifies initial context-mechanism-outcome configurations. The thesis provides evidence that suggests realist evaluation is an appropriate approach to address ongoing methodological problems in studying ways to reduce NTE ARAs