Longitudinal electrodermal recordings of mentally disabled individuals and their caretakers

BACKGROUND Almost no scientific observtions exist concerning the physiological changes and events that arise before nd during human agressive behavior. Yet, there are many instances where it might be of great benefit to have insight in these changes, for example when an individual has limited communicative capabilities to express their emotions and rising frustrations. In our project we focused on such a situation by measuring physiological changes of people with severe mental disabilities, who also consistently showed challenging behavior (CB) such as aggressive acts and self-injurious behavior. Caretakers often report being surprised by these outbursts and explicitly express a need for additional tools to gain insight in the arousal levels of their clients. The aim of our project was to investigate the potential value of ambulatory physiological measurements in bringing this insight to the caretakers. An additional goal was to also examine the relation between the physiological changes of the caretakers themselves and the CB of the clients. We did this because actions of direct care staff have been found to be antecedents of the aggressive behavior of clients, and therefore we wanted to investigate the possibility that heightened levels of arousal in caretakers might be associated with a higher likelihood of future aggressive behavior. METHOD We followed 9 individuals with severe mental disabilities and their regular caretakers during sessions of two to three hours on a fixed timeslot and day of the week over a period of months. During all those sessions (typically a total of 24 per client-caretaker couple), we measured electrodermal activity (EDA) with a wrist sensor, and we recorded the clients behavior on video. EDA, and the parameters that can be extracted from it, such as the number of skin conductance responses per minute, have been found to be a good estimate of the activity of the sympathetic part of the autonomic nervous systems. As such, it can be taken as a further operationalization of the arousal level of the client and caretaker, which was the dependent variable of interest for our project. The measurement device was the Q sensor "Curve" from Affectiva, which allows for wireless, non-intrusive measurements of EDA with a sample rate of 32 Hz (which is more than sufficient for state of the art analysis methods). A protocol was developed to realize these measurements, while minimizing distress for the clients (see Noordzij, Scholten, Laroy-Noordzij, 2012, Measuring Behavior). After each session caretakers noted whether any CB had occurred. Subsequently, trained professionals examined the videos and determined the nature, severity and onset of the CB. EDA parameters were extracted automatically both with computationally simple trough-to-peak analyses, and with more sophisticated decomposition analyses of the signal into its phasic and tonic components. RESULTS AND DISCUSSION As expected the participants displayed CB during many of the sessions. These events were typically associated with medium to highest amplitudes and frequencies of the electrodermal responses. Our data analysis also brought to light some of the complexities surrounding the determination of arousal levels of these clients. Even detailed viewing of the videos by trained professionals resulted in only moderate levels of inter-rater reliability concerning the severity CB and especially the precise onset of CB. This reflects the observation of experienced caretakers that the buildup phase towards CB is hard to detect. On the other hand, we also found low correlation between EDA fluctuations of caretakers and clients. This, and further video analysis, showed that caretakers did not continuously interact and track the arousal level of the clients on a behavioral level. This fact alone opens up a set of possibilities to create a monitoring system based on the EDA levels of client, which informs the caretaker when EDA levels are in a medium to high range (i.e. the only moments when CB occur). Currently, we are developing such a monitoring prototype, which, together with findings from our ongoing analysis of this rich data set will be further discussed during the presentation

Deceptive Intentions: Can Cues to Deception Be Measured before a Lie Is Even Stated?

Can deceitful intentions be discriminated from truthful ones? Previous work consistently demonstrated that deceiving others is accompanied by nervousness/stress and cognitive load. Both are related to increased sympathetic nervous system (SNS) activity. We hypothesized that SNS activity already rises during intentions to lie and, consequently, cues to deception can be detected before stating an actual lie. In two experiments, controlling for prospective memory, we monitored SNS activity during lying, truth telling, and truth telling with the aim of lying at a later instance. Electrodermal activity (EDA) was used as an indicator of SNS. EDA was highest during lying, and compared to the truth condition, EDA was also raised during the intention to deceive. Moreover, the switch from truth telling toward lying in the intention condition evoked higher EDA than switching toward non-deception related tasks in the lie or truth condition. These results provide first empirical evidence that increased SNS activity related to deception can be monitored before a lie is stated. This implies that cues to deception are already present during the mere intention to lie. © 2015 Ströfer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Atlas.txt : Exploring Lingusitic Grounding Techniques for Communicating Spatial Information to Blind Users

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Neural Correlates of Intentional Communication

We know a great deal about the neurophysiological mechanisms supporting instrumental actions, i.e., actions designed to alter the physical state of the environment. In contrast, little is known about our ability to select communicative actions, i.e., actions directly designed to modify the mental state of another agent. We have recently provided novel empirical evidence for a mechanism in which a communicator selects his actions on the basis of a prediction of the communicative intentions that an addressee is most likely to attribute to those actions. The main novelty of those findings was that this prediction of intention recognition is cerebrally implemented within the intention recognition system of the communicator, is modulated by the ambiguity in meaning of the communicative acts, and not by their sensorimotor complexity. The characteristics of this predictive mechanism support the notion that human communicative abilities are distinct from both sensorimotor and linguistic processes