Background: Human-computer interaction (HCI) is one of the daily triggering emotional events in today’s world and researchers in this area have been exploring different techniques to enhance emotional ability in computers. Due to privacy concerns and the laboratory's limited capability for gathering data from a large number of users, common machine learning techniques that are extensively used in emotion recognition tasks lack adequate data collection. To address these issues, we propose a decentralized framework based on the Federated Learning architecture where raw data is collected and analyzed locally. The effects of these analyses in large numbers of updates are transferred to a server to aggregate for the creation of a global model for the emotion recognition task using only Galvanic Skin Response (GSR) signals and their extracted features. 

Objectives: This thesis aims to explore how the CNN based federated learning approach can be used in emotion recognition considering data privacy protection and investigate if it reaches the same performance as basic centralized CNN.Methods: To investigate the effect of the proposed method in emotion recognition, two architectures including centralized and federated are designed with the CNN model. Then the results of these two architectures are compared to each other. The dataset used in our work is the CASE dataset. In federated architecture, we employ neurons and weights to train the models instead of raw data, which is used in the centralized architecture. 

Results: The performance results indicate that the proposed model not only can work well but also performs better than some other related work methods regarding valance accuracy. Besides, it also has the ability to collect more data from various sources and also protecting sensitive users’ data better by supporting tighter privacy regulations. The physiological data is inherently anonymous but when it comes to using it with other modalities such as video or voice, maintaining the same anonymity is challenging. 

Conclusions: This thesis concludes that the federated CNN based model can be used in emotion recognition systems and obtains the same accuracy performance as centralized architecture. Regarding classifying the valance, it outperforms some other state-of-the-art methods. Meanwhile, its federated nature can provide better privacy protection and data diversity for the emotion recognition system.