Malcolm Dcosta

Dissecting Driver Behaviors Under Cognitive, Emotional, Sensorimotor, and Mixed Stressors

In a simulation experiment we studied the effects of cognitive, emotional, sensorimotor, and mixed stressors on driver arousal and performance with respect to (wrt) baseline. In a sample of n = 59 drivers, balanced in terms of age and gender, we found that all stressors incurred significant increases in mean sympathetic arousal accompanied by significant increases in mean absolute steering. The latter, translated to significantly larger range of lane departures only in the case of sensorimotor and mixed stressors, indicating more dangerous driving wrt baseline. In the case of cognitive or emotional stressors, often a smaller range of lane departures was observed, indicating safer driving wrt baseline. This paradox suggests an effective coping mechanism at work, which compensates erroneous reactions precipitated by cognitive or emotional conflict. This mechanisms’ grip slips, however, when the feedback loop is intermittently severed by sensorimotor distractions. Interestingly, mixed stressors did not affect crash rates in startling events, suggesting that the coping mechanism’s compensation time scale is above the range of neurophysiological latency.

A multimodal dataset for various forms of distracted driving

We describe a multimodal dataset acquired in a controlled experiment on a driving simulator. The set includes data for n=68 volunteers that drove the same highway under four different conditions: No distraction, cognitive distraction, emotional distraction, and sensorimotor distraction. The experiment closed with a special driving session, where all subjects experienced a startle stimulus in the form of unintended acceleration—half of them under a mixed distraction, and the other half in the absence of a distraction. During the experimental drives key response variables and several explanatory variables were continuously recorded. The response variables included speed, acceleration, brake force, steering, and lane position signals, while the explanatory variables included perinasal electrodermal activity (EDA), palm EDA, heart rate, breathing rate, and facial expression signals; biographical and psychometric covariates as well as eye tracking data were also obtained. This dataset enables research into driving behaviors under neatly abstracted distracting stressors, which account for many car crashes. The set can also be used in physiological channel benchmarking and multispectral face recognition.

Evaluating smartphone-based user interface designs for a 2D psychological questionnaire

This study explored various user interface designs to transition a two dimensional (2D) questionnaire from its paper-and-pencil testing format to the mobile platform. The current administration of the test limits its usage beyond the lab environment. Creating a mobile version would facilitate ubiquitous administration of the test. Yet, the mobile design must be at least as good as its paper-based counterpart in terms of input accuracy and user interaction efforts. We developed four user interface designs, each of which featured a specific interaction approach. These approaches included displaying the 2D space of the questionnaire in its original form (M1), inputting one variable at a time on the 2D space (M2), dissolving the 2D space into two one-dimensional ordinal scales (M3), and orienting the input selections to the diagonal axes (M4). The designs were tested by a total of 34 participants, aged 18 to 52 years. The study results find the first three interaction approaches (M1-M3) effective but the fourth approach inefficient. Furthermore, the results indicate that the two-tap designs (M2 and M3) are equally as good as the one-tap design (M1).

Delineating the Operational Envelope of Mobile and Conventional EDA Sensing on Key Body Locations

Electrodermal activity (EDA) is an important affective indicator, measured conventionally on the fingers with desktop sensing instruments. Recently, a new generation of wearable, battery-powered EDA devices came into being, encouraging the migration of EDA sensing to other body locations. To investigate the implications of such sensor/location shifts in psychophysiological studies we performed a validation experiment. In this experiment we used startle stimuli to instantaneously arouse the sympathetic system of n=23 subjects while sitting. Startle stimuli are standard but minimal stressors, and thus ideal for determining the sensor and location resolution limit. The experiment revealed that precise measurement of small EDA responses on the fingers and palm is feasible either with conventional or mobile EDA sensors. By contrast, precise measurement of small EDA responses on the sole is challenging, while on the wrist even detection of such responses is problematic for both EDA modalities. Given that affective wristbands have emerged as the dominant form of EDA sensing, researchers should beware of these limitations.

Perinasal indicators of malevolence

Several decades of research into detecting lies has resulted in a large number of available of techniques among both behavioral and physiological channels. However only in the recent past, have researchers started to focus more on ways to detect ill-intent. Persons lying under high stakes situations show detectable changes in behavior. Similarly while lying to conceal ones true intent, one exhibits similar characteristics. This work presents a fast, convenient and discrete way of monitoring facial physiology using thermal imaging to detect when a person is lying about their intentions. Its application is suitable for screening in airports, border crossing and other venues with large transit volumes.

Perinasal indicators of deceptive behavior

High-stakes lying causes detectable changes in human behavior and physiology. Lie detection techniques based on behavior analysis are unobtrusive, but often require laborintensive efforts. Lie detection techniques based on physiological measurements are more amenable to automated analysis and perhaps more objective, but their often obtrusive nature makes them less suitable for realistic studies. In this paper we present a novel lie detection framework. At the core of this framework is a physiological measurement method that quantifies stress-induced facial perspiration via thermal imagery. The method uses a wavelet-based signal processing algorithm to construct a feature vector of dominant perinasal perspiration frequencies. Then, pattern recognition algorithms classify the subjects into deceptive or truthful by comparing the extracted features between the hard and easy questioning segments of an interview procedure. We tested the framework on thermal clips of 40 subjects who underwent interview for a mock crime. We used 25 subjects to train the classifiers and 15 subjects for testing. The method achieved 80% success rate in blind predictions. This framework can be generalized across experimental designs, as the classifiers do not depend on the number or order of interview questions.

SubjectBook: Hypothesis-Driven Ubiquitous Visualization for Affective Studies

Analyzing affective studies is challenging because they feature multimodal data, such as psychometric scores, imaging sequences, and signals from wearable sensors, with the latter streaming continuously for hours on end. Meaningful visual representations of such data can greatly facilitate insights and qualitative analysis. Various tools that were proposed to tackle this problem provide visualizations of the original data only; they do not support higher level abstractions. In this paper, we introduce SubjectBook, an interactive web-based tool for synchronizing, visualizing, exploring, and analyzing affective datasets. Uniquely, SubjectBook operates at three levels of abstraction, mirroring the stages of quantitative analysis in hypothesis-driven research. The top level uses a grid visualization to show the studys significant outcomes across subjects. The middle level summarizes, for each subject, context information along with the explanatory and response measurements in a construct reminiscent of an ID card. This enables the analyst to appreciate within subject phenomena. Finally, the bottom level brings together detailed information concerning the inner and outer state of human subjects along with their real-world interactions - a visualization fusion that supports cause and effect reasoning at the experimental session level. SubjectBook was evaluated on a case study focused on driving behaviors.

Connecting Past with Present: A Mixed-Methods Science Ethics Course and its Evaluation

We present a graduate science ethics course that connects cases from the historical record to present realities and practices in the areas of social responsibility, authorship, and human/animal experimentation. This content is delivered with mixed methods, including films, debates, blogging, and practicum; even the instructional team is mixed, including a historian of science and a research scientist. What really unites all of the course’s components is the experiential aspect: from acting in historical debates to participating in the current scientific enterprise. The course aims to change the students’ culture into one deeply devoted to the science ethics cause. To measure the sought after cultural change, we developed and validated a relevant questionnaire. Results of this questionnaire from students who took the course, demonstrate that the course had the intended effect on them. Furthermore, results of this questionnaire from controls indicate the need for cultural change in that cohort. All these quantitative results are reinforced by qualitative outcomes.

Turning security monitoring into an engaging high performance task

We present a novel method to improve the engagement and performance of security guards in tasks involving the monitoring of multiple video feeds. The method is based on multiplexing to the monitoring task symbiotic activities that are entertaining in nature and supportive to (not detracting from) this task. A longitudinal crossover experiment that lasted 10 days on n=15 security guards confirmed the methods superiority in terms of task engagement and performance with respect to the standard method.