Master's Thesis

Analyzing in-ear and 8-Channel brain electroencephalogram (EEG) signals to detect anxiety and depression

Final Thesis 7.63 MB

Author of thesis: Ing. Milan Tichavský

Acad. year: 2025/2026

Supervisor: prof. Aamir Saeed Malik, Ph.D.

Reviewer: Muhammad Asad Zaheer

Abstract:

This thesis focuses on detection of anxiety and depression from resting-state electroencephalogram (EEG) signals using deep learning. Three publicly available datasets are combined into a unified multi-site framework covering four clinical groups: healthy individuals, anxiety, depression, and comorbid anxiety-depression. Several architectures are designed and evaluated, including spectrogram-based convolutional and transformer models as well
as raw-EEG approaches. The best-performing model, a spectrogram CNN-transformer hybrid, achieves 82.96 % subject-level accuracy for binary classification (healthy vs. pathological) on eight EEG channels. In-ear variant reaches 79.27 %. Both were evaluated under 10-fold subject-independent cross-validation with results that are statistically indistinguishable given the evaluation setup. For four-class classification, 67 % subject accuracy is achieved, representing a 2.7× improvement over the majority-class baseline. The key finding is that a single in-ear electrode can match the diagnostic accuracy of an eight-channel cap, supporting the viability of low-cost wearable EEG for mental health screening.

Keywords:

in-ear EEG, wearable EEG, EEG classification, deep learning, transformer, convolutional neural network, spectrogram, anxiety detection, depression detection, mental health screening

Date of defence

22.06.2026

Result of the defence

Defended (thesis was successfully defended)

znamkaAznamka

Grading

A

Process of defence

Student nejprve prezentoval výsledky, kterých dosáhl v rámci své práce. Komise se poté seznámila s hodnocením vedoucího a posudkem oponenta práce. Student následně odpověděl na otázky oponenta a na další otázky přítomných. Komise se na základě posudku oponenta, hodnocení vedoucího, přednesené prezentace a odpovědí studenta na položené otázky rozhodla práci hodnotit stupněm A.

Topics for thesis defence

  1. Why did you choose deep learning instead of traditional machine learning methods
  2. Which channels contributed the most to the final results?
  3. Why only a 10 second segment selected for most experiments?
  4. How would you improve the performance of the multiclass model in future work? if you have too
  5. What was the biggest challenge when combining multiple datasets?

Language of thesis

English

Faculty

Department

Study programme

Information Technology and Artificial Intelligence (MITAI)

Specialization

Machine Learning (NMAL)

Composition of Committee

prof. Dr. Ing. Jan Černocký (předseda)
prof. Ing. Martin Čadík, Ph.D. (místopředseda)
doc. Ing. Vladimír Janoušek, Ph.D. (člen)
doc. Ing. Michal Bidlo, Ph.D. (člen)
doc. Ing. František Zbořil, Ph.D. (člen)
Ing. Petr Veigend, Ph.D. (člen)

Supervisor’s report
prof. Aamir Saeed Malik, Ph.D.

The student has completed all the objectives specified in the project description. He has optimized a deep learning-based approach for the detection of anxiety and depression dealing with it as a multiclass problem. He has tested it with three public datasets and the results are promising. The work is publishable as a conference paper.

Evaluation criteria Verbal classification
Informace k zadání

The thesis was related to detection of anxiety and depression using low density EEG, that is, 8 channels EEG and 1 Channel Ear EEG. The work involved simultaneous detection of anxiety and depression and hence is a multiclass problem. The work was challenging because it not only required knowledge in signal processing and the machine learning but also required understanding of the mental health disorders. The complexity of the project increased due to the multi-level classification, because of similarity of anxiety with depression in terms of neural mechanisms. The student optimized various deep learning models to achieve this objective and tested it on three public datasets. The results are promising.

Aktivita při dokončování

The student regularly consulted me before the submission of the thesis. The work was challenging because of the complexity of brain EEG signals which include many electrodes and requires extensive pre-processing. Also, there is a learning curve as it’s a multidisciplinary topic. The student was able to complete all the development in time and was able to submit the thesis within the give timeframe.

Publikační činnost, ocenění

The thesis is well written and contains content which is publishable as a conference paper. The student is encouraged to prepare the draft for the paper.

Práce s literaturou

The student has provided overview of brain and neuroimaging techniques in chapter 2 while the literature review in chapter 3. Sections 2.1 and 2.2 discuss the anatomy of the brain and the corresponding neuroimaging techniques are discussed in section 2.3. In sections 3.1, 3.2 and 3.3, research related to anxiety and depression is presented. Section 3.4 provides details of existing deep learning models in this arena. Overall, the literature review is satisfactory.

Aktivita během řešení, konzultace, komunikace

The student had weekly meetings and he came to meetings on time and he regularly attended the meetings. I found him to be punctual and hardworking student. He faced many challenges and worked hard to overcome the challenges. He was very active and quite focused on his project.

Points proposed by supervisor: 90

Grade proposed by supervisor: A

Reviewer’s report
Muhammad Asad Zaheer

The thesis addresses a relevant and tough research problem and shows technical competence. The proposed solution implemented, and validated, while the obtained results indicate promising practical applicability. Though I have few minor reservations, the overall quality of the work is excellent and fully satisfies the requirements of a Master's thesis.

Evaluation criteria Verbal classification Points
Rozsah splnění požadavků zadání

Evaluation level: zadání téměř splněno

The assignment requirements have been fully fulfilled. The thesis successfully addresses all objectives. A minor reservation concerns the limited discussion of model explainability and interpretation of the learned features, which could have provided additional information to the decision-making process of the proposed deep learning models. However, that does not affect the overall thesis because that was not the primary assignment of the thesis.

Rozsah technické zprávy

Evaluation level: je v obvyklém rozmezí

The thesis meets the described length and overall is well structured. A minor reservation is that Chapter 2 could have included a subsection discussing the relationship between anxiety and depression. 

Prezentační úroveň technické zprávy

Overall thesis is logically structured, nicely written, and easy to follow. The chapters are in a coherent manner and provide detail for understanding the proposed solution. Minor reservations about the 2nd chapter, which could have a summary table comparing related studies, and absence of a visualization showing the selected EEG electrode configuration.

84
Formální úprava technické zprávy

The report is written in clearly, and the formatting is consistent throughout. Minor stylistic issues can be observed, including occasional use of a less formal writing style. These issues are minor and do not negatively affect the readability.

90
Práce s literaturou

The thesis uses relevant literature closely related to the topic. Deep learning approaches and recent EEG studies are discussed in literature chapter. A minor point I want to raise in the literature review, is comparative summary table of the reviewed studies and a broader discussion of traditional machine learning approaches alongside deep learning methods. 

91
Realizační výstup

The solution is of a high technical standard and successfully fulfills the objectives of the thesis. The implemented models are evaluated using appropriate validations, and the work includes deployment through a FastAPI-based service. 

94
Využitelnost výsledků

The thesis provides original experimental results, including the comparison of multiple deep learning architectures and in-ear EEG for anxiety and depression. The binary classification results are good enough, while the four-class classification task still needs further improvements. The presented work provides a strong base for future work and could potentially lead to a publishable research contribution if complemented with additional aspects such as explainable AI, uncertainty estimation.

Náročnost zadání

Evaluation level: značně obtížné zadání

The assignment can be considered very difficult for a master student. The work required interdisciplinary knowledge spanning EEG signal processing, machine learning, deep learning. It invloves combining multiple datasets, and implementing and evaluating multiple deep learning models, comparing 8-channel EEG with single channel ear EEG, and implementing a system integrated into a cloud based platform.

Topics for thesis defence:
  1. Why did you choose deep learning instead of traditional machine learning methods
  2. Which channels contributed the most to the final results?
  3. Why only a 10 second segment selected for most experiments?
  4. How would you improve the performance of the multiclass model in future work? if you have too
  5. What was the biggest challenge when combining multiple datasets?
Points proposed by reviewer: 93

Grade proposed by reviewer: A

Responsibility: Mgr. et Mgr. Hana Odstrčilová