Investigating Cognitive Load in Energy Network Control Rooms: Recommendations for Future Designs.

This study analyzed and explored the cognitive load of Australian energy market operators managing one of the longest inter-connected electrical networks in the world. Each operator uses a workstation with seven screens in an active control room environment, with a large coordination screen to show information and enable collaboration between different control centers. Cognitive load was assessed during both training scenarios and regular control room operations via the integration of subjective and physiological measures. Eye-tracking glasses were also used to analyze the operators gaze behavior. Our results indicate that different events (normal or unexpected), different participants for the same session, and different periods of one session all have varying degrees of cognitive load. The system design was observed to be inefficient in some situations and to have an adverse affect on cognitive load. In critical situations for instance, operator collaboration was high and the coordination screen was used heavily when collaborating between two control centers, yet integration with the system could be improved. Eye tracking data analysis showed that the layout of applications across the seven screens was not optimal for many tasks. Improved layout strategies, potential combination of applications, redesigning of certain applications, and linked views are all recommended for further exploration in addition to improved integration of procedures and linking alarms to visual cues.

Scalability of Network Visualisation from a Cognitive Load Perspective.

Node-link diagrams are widely used to visualise networks. However, even the best network layout algorithms ultimately result in 'hairball' visualisations when the graph reaches a certain degree of complexity, requiring simplification through aggregation or interaction (such as filtering) to remain usable. Until now, there has been little data to indicate at what level of complexity node-link diagrams become ineffective or how visual complexity affects cognitive load. To this end, we conducted a controlled study to understand workload limits for a task that requires a detailed understanding of the network topology-finding the shortest path between two nodes. We tested performance on graphs with 25 to 175 nodes with varying density. We collected performance measures (accuracy and response time), subjective feedback, and physiological measures (EEG, pupil dilation, and heart rate variability). To the best of our knowledge this is the first network visualisation study to include physiological measures. Our results show that people have significant difficulty finding the shortest path in high density node-link diagrams with more than 50 nodes and even low density graphs with more than 100 nodes. From our collected EEG data we observe functional differences in brain activity between hard and easy tasks. We found that cognitive load increased up to certain level of difficulty after which it decreased, likely because participants had given up. We also explored the effects of global network layout features such as size or number of crossings, and features of the shortest path such as length or straightness on task difficulty. We found that global features generally had a greater impact than those of the shortest path.

Coping associated with compulsive buying tendency.

Research on general coping is limited within compulsive buying (CB) literature. Nevertheless, other behavioural addictions and hoarding might provide insights into coping in CB. One-hundred and ninety-nine participants (M age = 52.72, SD = 16.06; 50.3% female, 1% unknown sex) completed online questionnaires. Mental and behavioural disengagements were hypothesized to predict greater self-reported CB tendency. Whilst these relationships were found in the correlations, a regression analysis indicated that only mental disengagement significantly predicted CB tendency. Additionally, the exploration of denial and substance use identified that denial was an important predictor of CB tendency coping. The relationship between CB tendency and substance use could not be explored given the large degree of participants reporting minimal scores. CB tendency is associated with maladaptive mental disengagement, denial and lack of acceptance coping strategies, which could be useful to consider in therapy.

Working memory load affects early affective responses to concrete and abstract words differently: Evidence from ERPs.

Early posterior negativity (EPN) is an early-occurring, event-related, potential that is elicited by pictures and words that have highly arousing characteristics. Whilst EPN has been found with words presented in isolation several times, different types of words have shown quite different effects across different types of tasks. One possible reason for this is that memory and attentional demands may affect the way semantic features of words are processed, and this may modulate EPN. This was investigated in a silent reading task using abstract and concrete words of negative and neutral valence and a dual phonological working memory task to manipulate memory load. The results showed that abstract but not concrete words elicited EPN, and this may have affected downstream processing. Further analyses examining alpha desynchronization showed that negative concrete words appeared to be significantly affected by the memory load manipulation, unlike negative abstract words. These results provide evidence that the processing of features in negative concrete words is more affected by working memory and attentional demands than the processing of features in negative abstract words, and this may be responsible for the failure of negative concrete words to elicit EPN in this study. Thus, the extent to which words elicit EPN appears to be dependent on both their semantic representations and competing cognitive processes. These results provide a potential explanation for some of the differences that have been reported in previous experiments as well as insight into how memory and attention can affect the processing of the semantic features of words.

Relationships that compulsive buying has with addiction, obsessive-compulsiveness, hoarding, and depression.

BACKGROUND AND OBJECTIVES: Compulsive buying has been associated with addiction, depression, and obsessive-compulsive disorder, as well as hoarding. The present study investigated the relationship that compulsive buying (CB) has with 'addictive' (i.e., sensitivity to reward), obsessive-compulsive, and depressive phenomena, after controlling for hoarding, substance dependence, manic, and Borderline Personality Disorder symptoms. METHODS: 87 participants from a community population completed the online questionnaires for the study, however 70 participants (M=29.19, SD=10.45; 70% were female) were used in the analyses because of exclusion criteria. RESULTS: As expected, CB measures correlated with hoarding, depression, sensitivity to reward, and, but less so, obsessive-compulsive measures. Sensitivity to reward was the most important predictor of CB severity, compared to obsessive-compulsive and depression symptoms. Hoarding was also an important predictor of CB severity. LIMITATIONS: Small sample size meant gender comparisons could not be made, and the use of a novel, communicated questionnaire meant that interpretation should be considered conservatively. CONCLUSIONS: Overall, findings suggest that CB may be most closely related to the phenomena associated with addiction (an increased sensitivity to reward), rather than obsessive-compulsive or depression symptoms. Hoarding and reward sensitivity perhaps might separate compulsive buying from ordinary and recreational shopping.

Cognitive processes associated with compulsive buying behaviours and related EEG coherence.

The behavioural and cognitive phenomena associated with Compulsive Buying (CB) have been investigated previously but the underlying neurophysiological cognitive process has received less attention. This study specifically investigated the electrophysiology of CB associated with executive processing and cue-reactivity in order to reveal differences in neural connectivity (EEG Coherence) and distinguish it from characteristics of addiction or mood disorder. Participants (N=24, M=25.38 yrs, S.D.=7.02 yrs) completed the Sensitivity to Punishment Sensitivity to Reward Questionnaire and a visual memory task associated with shopping items. Sensitivities to reward and punishment were examined with EEG coherence measures for preferred and non-preferred items and compared to CB psychometrics. Widespread EEG coherence differences were found in numerous regions, with an apparent left shifted lateralisation for preferred and right shifted lateralisation for non-preferred items. Different neurophysiological networks presented with CB phenomena, reflecting cue reactivity and episodic memory, from increased arousal and attachment to items.

The selectivity of beauveriolide derivatives in inhibition toward the two isozymes of acyl-CoA: cholesterol acyltransferase.

The selectivity of synthetic beauveriolide derivatives in inhibition toward the two isozymes of acyl-CoA : cholesterol acyltrasferase (ACAT), ACAT1 and ACAT2, was studied in cell-based assays using ACAT1- or ACAT2-expressing Chinese hamster ovary (CHO) cells. NBV274, 285 and 300 showed ACAT1 selective inhibition similar to that of natural beauveriolides I and III, NBV345 inhibited both isozymes with similar potency, but NBV281, 331 and 249 were found to selectively inhibit the ACAT2 isozyme. The structure-activity relationships indicated that a subtle structural difference in beauveriolide derivatives can affect the selectivity of inhibition of the ACAT isozymes.