| Literature DB >> 35712070 |
Li Liu1,2, Yunfeng Ji1, Yun Gao1, Tao Li1, Wei Xu1.
Abstract
Stress is an unavoidable problem for today's college students. Stress can arouse strong personal emotional and behavioral responses. Compared with other groups of the same age, college students have a special way of life and living environment. They have complex interpersonal relationships and relatively weak social support systems. At the same time, they also face fierce competition in both academic and employment. However, they lack the skills to deal with the crisis and are reluctant to ask others for help, which leads to a simultaneous increase in mental stress. The pressure on college students mainly comes from study, family, social, employment, society, and economy. When students face multiple pressures from family, school, society, etc., some students are prone to some psychological problems due to their own personality or external environment and other reasons. Therefore, regular assessment of students' stress status is an important means to prevent college students' psychological problems. Considering that in real life, the number of students whose pressure is within the tolerable range is the majority, while the number of students who are under too much pressure is a minority. Therefore, the actual dataset to be identified belongs to a kind of imbalanced data. In this study, an improved extreme learning machine (IELM) is used to improve the performance of the recognition model as much as possible. IELM takes the idea of label weighting as the starting point, introduces the AdaBoost algorithm, and combines its weight distribution with the label weighted extreme learning machine (ELM). During the weight update process, the advantage of the imbalanced nature of multi-label datasets is taken. IELM was used to classify EEG data to determine the stress level of college students. The experimental results demonstrate that the algorithm used in this study has excellent classification performance and can accurately assess students' stress levels. The accurate assessment of stress has provided a solid foundation for the development of students' mental health and has significant practical implications.Entities:
Mesh:
Year: 2022 PMID: 35712070 PMCID: PMC9197644 DOI: 10.1155/2022/4565968
Source DB: PubMed Journal: Comput Intell Neurosci
Brain wave band details.
| Name | Frequency (Hz) | Location | Generated time |
|---|---|---|---|
|
| 0.5 < 4 | Forehead in adults, back of brain in children | Occurs mostly in the brains of infants, but also occurs when adults are in deep sleep, coma, or anesthesia |
|
| 4–7 | Brain regions unrelated to hand function | Occurs in young children and adolescents, but also in adults who are tired but conscious |
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| 8–15 | The back of the brain, the resting state is concentrated in the center | Relaxed/contemplative state with eyes closed |
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| 16–31 | The brain is symmetrically distributed on both sides, with a prominent forehead | Positive thinking, focus, vigilance, anxiety |
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| 32–45 | Somatosensory cortex | Short-term memory, hearing, and touch, multisensory processing |
Figure 1EEG-based stress assessment process.
Linear and nonlinear characteristics of EEG.
| Feature type | Feature name |
|---|---|
| Linear feature | Full-band center frequency, Hjorth parameter, peak-to-peak, variance, slope, kurtosis |
| Nonlinear feature | CO complexity, correlation dimension, power spectral entropy, full-band power spectral entropy, Shannon entropy, Kolmogorov entropy |
Stress self-assessment form.
| Subject number | ||||
|---|---|---|---|---|
| Gender | Male ☐ | Female ☐ | ||
| Grade | 1 ☐ | 2 ☐ | 3 ☐ | |
| Study stress | 1 ☐ | 2 ☐ | 3 ☐ | |
| Life pressure | 1 ☐ | 2 ☐ | 3 ☐ | |
| Family stress | 1 ☐ | 2 ☐ | 3 ☐ | |
| Overall pressure | 1 ☐ | 2 ☐ | 3 ☐ | |
Classification accuracy based on ELM under four features.
| Feature |
|
|
|
|
|
|---|---|---|---|---|---|
| Hurst index | 0.7122 | 0.6945 | 0.7342 | 0.5898 | 0.6342 |
| Fluctuation index | 0.8098 | 0.8120 | 0.7788 | 0.7556 | 0.7861 |
| Sample entropy | 0.6541 | 0.5987 | 0.5062 | 0.6012 | 0.5142 |
| Permutation entropy | 0.7193 | 0.6298 | 0.5865 | 0.7181 | 0.5880 |
Figure 2Comparison chart of classification accuracy based on ELM under four features.
Classification accuracy based on IELM under four features.
| Feature |
|
|
|
|
|
|---|---|---|---|---|---|
| Hurst index | 0.7778 | 0.7624 | 0.7997 | 0.6175 | 0.7037 |
| Fluctuation index | 0.8134 | 0.8878 | 0.7959 | 0.7602 | 0.8178 |
| Sample entropy | 0.7190 | 0.6530 | 0.5368 | 0.6091 | 0.5392 |
| Permutation entropy | 0.7327 | 0.6490 | 0.5997 | 0.7204 | 0.5914 |
Figure 3Comparison chart of classification accuracy based on IELM under four features.
Figure 4Classification accuracy of 4 features. (a) Hurst index. (b) Fluctuation index. (c) Sample entropy. (d) Permutation entropy.
Details of each feature weight.
| Feature |
|
|
|
|
|
|---|---|---|---|---|---|
| Hurst index | 0.2556 | 0.2582 | 0.2927 | 0.2281 | 0.2653 |
| Fluctuation index | 0.2673 | 0.3007 | 0.2913 | 0.2808 | 0.3084 |
| Sample entropy | 0.2363 | 0.2213 | 0.1965 | 0.2250 | 0.2033 |
| Permutation entropy | 0.2408 | 0.2198 | 0.2195 | 0.2661 | 0.2230 |
Classification accuracy under different feature combinations.
| Feature combination |
|
|
|
|
|
|---|---|---|---|---|---|
| Without weighted feature combination | 0.8210 | 0.8932 | 0.8090 | 0.7881 | 0.8012 |
| With weighted feature combination | 0.8340 | 0.9001 | 0.8559 | 0.8293 | 0.8749 |
Figure 5Comparison chart of classification accuracy under different feature combinations.
Experimental results of different classification models.
| Index/model | SVM | Linear SVM | RBFNN | RF | ELM | IELM |
|---|---|---|---|---|---|---|
| Accuracy | 0.6275 | 0.6598 | 0.7609 | 0.7567 | 0.7912 | 0.8728 |
| Recall | 0.6515 | 0.6702 | 0.7122 | 0.6547 | 0.7687 | 0.8913 |
Figure 6Accuracy and recall of different classification models.