Unsupervised Multi-Modal Representation Learning for Affective Computing with Multi-Corpus Wearable Data

With recent developments in smart technologies, there has been a growing focus on the use of artificial intelligence and machine learning for affective computing to further enhance the user experience through emotion recognition. Typically, machine learning models used for affective computing are trained using manually extracted features from biological signals. Such features may not generalize well for large datasets and may be sub-optimal in capturing the information from the raw input data. One approach to address this issue is to use fully supervised deep learning methods to learn latent representations of the biosignals. However, this method requires human supervision to label the data, which may be unavailable or difficult to obtain. In this work we propose an unsupervised framework reduce the reliance on human supervision. The proposed framework utilizes two stacked convolutional autoencoders to learn latent representations from wearable electrocardiogram (ECG) and electrodermal activity (EDA) signals. These representations are utilized within a random forest model for binary arousal classification. This approach reduces human supervision and enables the aggregation of datasets allowing for higher generalizability. To validate this framework, an aggregated dataset comprised of the AMIGOS, ASCERTAIN, CLEAS, and MAHNOB-HCI datasets is created. The results of our proposed method are compared with using convolutional neural networks, as well as methods that employ manual extraction of hand-crafted features. The methodology used for fusing the two modalities is also investigated. Lastly, we show that our method outperforms current state-of-the-art results that have performed arousal detection on the same datasets using ECG and EDA biosignals. The results show the wide-spread applicability for stacked convolutional autoencoders to be used with machine learning for affective computing.

Classification of Cognitive Load and Expertise for Adaptive Simulation using Deep Multitask Learning

Simulations are a pedagogical means of enabling a risk-free way for healthcare practitioners to learn, maintain, or enhance their knowledge and skills. Such simulations should provide an optimum amount of cognitive load to the learner and be tailored to their levels of expertise. However, most current simulations are a one-type-fits-all tool used to train different learners regardless of their existing skills, expertise, and ability to handle cognitive load. To address this problem, we propose an end-to-end framework for a trauma simulation that actively classifies a participant's level of cognitive load and expertise for the development of a dynamically adaptive simulation. To facilitate this solution, trauma simulations were developed for the collection of electrocardiogram (ECG) signals of both novice and expert practitioners. A multitask deep neural network was developed to utilize this data and classify high and low cognitive load, as well as expert and novice participants. A leave-one-subject-out (LOSO) validation was used to evaluate the effectiveness of our model, achieving an accuracy of 89.4% and 96.6% for classification of cognitive load and expertise, respectively.