Deep Learning for Natural Language Processing: A Review of Models and Applications

  • Authors

    • Renjbar Sh. Othman Duhok Polytechnic University, Technical Institute of Amedi, Department of Information Technology, Duhok, Kurdistan Region, Iraq and Akre University for Applied Sciences, Technical College of Informatics-Akre, Department of Information Technology, Akre, Kurdistan Region, ‎Iraq
    • Ibrahim Mahmood Ibrahim Akre University for Applied Sciences, Technical College of Informatics-Akre, Department of Computer Networks and Information Security, ‎Kurdistan Region, Iraq
    https://doi.org/10.14419/t1xnaq87

    Received date: April 24, 2025

    Accepted date: June 15, 2025

    Published date: August 29, 2025

  • Deep Learning; Natural Language Processing; Transformer Models; Neural Network Architectures; Sentiment Analysis; Text Classification; ‎Multimodal and Hybrid Models‎.
  • Abstract

    This review provides a critical analysis of the transformative impact of deep learning on the advancement of Natural Language Processing ‎‎(NLP). With the increasing volume of unstructured textual data, traditional rule-based and statistical methodologies have demonstrated limitations in effectively capturing the intricacies of human language. In contrast, deep learning models, including Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs), and transformer-based architectures such as BERT and GPT, have significantly ‎enhanced NLP capabilities by facilitating context-aware, scalable, and highly accurate language comprehension. The primary objective of this ‎review is to deliver a comprehensive synthesis of deep learning architectures utilized in essential NLP tasks, including sentiment analysis, ‎text classification, machine translation, and question answering. Additionally, it examines their evolution, key applications, and comparative ‎performance across various domains. By reviewing recent literature from 2021 to 2025, this analysis also emphasizes hybrid models, multimodal systems, and adaptations for low-resource environments. The goal is to identify emerging trends, challenges (e.g., interpretability, ‎computational cost), and future directions, including data augmentation, self-supervised learning, and cross-domain generalization, ultimately-‎ly guiding researchers towards the development of more adaptive and trustworthy NLP systems‎.

  • References

    1. A. Torfi, R. A. Shirvani, Y. Keneshloo, N. Tavaf, and E. A. Fox, “Natural Language Processing Advancements By Deep Learning: A Survey,” pp. 1–23, 2020, [Online]. Available: http://arxiv.org/abs/2003.01200.
    2. A. Raj, R. Jindal, A. K. Singh, and A. Pal, “A Study of Recent Advancements in Deep Learning for Natural Language Processing,” Proc. - 2023 IEEE World Conf. Appl. Intell. Comput. AIC 2023, pp. 300–306, 2023, https://doi.org/10.1109/AIC57670.2023.10263979.
    3. K. MOHAMAD and K. M. KARAOĞLAN, “Enhancing Deep Learning-Based Sentiment Analysis Using Static and Contextual Language Models,” Bitlis Eren Üniversitesi Fen Bilim. Derg., vol. 12, no. 3, pp. 712–724, 2023, https://doi.org/10.17798/bitlisfen.1288561.
    4. P. R. Kshirsagar, D. H. Reddy, M. Dhingra, D. Dhabliya, and A. Gupta, “A Review on Application of Deep Learning in Natural Language Processing,” Proc. 5th Int. Conf. Contemp. Comput. Informatics, IC3I 2022, pp. 1834–1840, 2022, https://doi.org/10.1109/IC3I56241.2022.10073309.
    5. E. O. Arkhangelskaya and S. I. Nikolenko, “Deep Learning for Natural Language Processing: A Survey,” J. Math. Sci. (United States), vol. 273, no. 4, pp. 533–582, 2023, https://doi.org/10.1007/s10958-023-06519-6.
    6. Z. Wang and Z. Zhang, “Research Convey on Text Classification Method based on Deep Learning,” 2022 7th Int. Conf. Intell. Comput. Signal Process. ICSP 2022, pp. 285–288, 2022, https://doi.org/10.1109/ICSP54964.2022.9778518.
    7. M. Haroon, “Deep Learning Based Question Answering System: A Review,” 2019, https://doi.org/10.20944/preprints202312.1739.v1.
    8. R. Rejimoan, B. Gnanapriya, and J. S. Jayasudha, “A Comprehensive Review on Deep Learning Approaches for Question Answering and Machine Reading Comprehension in NLP,” 2nd Ed. IEEE Delhi Sect. Own. Conf. DELCON 2023 - Proc., pp. 1–6, 2023, https://doi.org/10.1109/DELCON57910.2023.10127327.
    9. B. Alshemali and J. Kalita, “Improving the Reliability of Deep Neural Networks in NLP: A Review,” Knowledge-Based Syst., vol. 191, p. 105210, 2020, https://doi.org/10.1016/j.knosys.2019.105210.
    10. J. Liu, X. Chu, Y. Wang, and M. Wang, “Deep Text Retrieval Models based on DNN, CNN, RNN and Transformer: A review,” Proc. 2022 8th IEEE Int. Conf. Cloud Comput. Intell. Syst. CCIS 2022, pp. 391–400, 2022, https://doi.org/10.1109/CCIS57298.2022.10016379.
    11. Y. Chen, H. Wang, K. Yu, and R. Zhou, “Artificial Intelligence Methods in Natural Language Processing: A Comprehensive Review,” Highlights Sci. Eng. Technol., vol. 85, pp. 545–550, 2024, https://doi.org/10.54097/vfwgas09.
    12. D. W. Otter, J. R. Medina, and J. K. Kalita, “A Survey of the Usages of Deep Learning for Natural Language Processing,” IEEE Trans. Neural Networks Learn. Syst., vol. 32, no. 2, pp. 604–624, 2021, https://doi.org/10.1109/TNNLS.2020.2979670.
    13. Z. Yang, “Deep Learning Applications in Natural Language Processing and Optimization Strategies,” pp. 1–5. https://doi.org/10.70767/jmec.v1i2.257.
    14. D. S. Asudani, N. K. Nagwani, and P. Singh, Impact of word embedding models on text analytics in deep learning environment: a review, vol. 56, no. 9. Springer Netherlands, 2023. https://doi.org/10.1007/s10462-023-10419-1.
    15. Muhammad Zulqarnain et al., “Text Classification Using Deep Learning Models: A Comparative Review,” Cloud Comput. Data Sci., pp. 80–96, 2023, https://doi.org/10.37256/ccds.5120243528.
    16. M. Gupta, S. K. Verma, and P. Jain, “Detailed Study of Deep Learning Models for Natural Language Processing,” Proc. - IEEE 2020 2nd Int. Conf. Adv. Comput. Commun. Control Networking, ICACCCN 2020, pp. 249–253, 2020, https://doi.org/10.1109/ICACCCN51052.2020.9362989.
    17. S. Singh, N. Zaidi, and A. Singh, “Deep learning for natural language understanding: A review of recent advances,” Int. J. Appl. Res., vol. 4, no. 10, pp. 310–314, 2018, https://doi.org/10.22271/allresearch.2018.v4.i10d.11459.
    18. Z. Xu, “Research on Deep Learning in Natural Language Processing,” Adv. Comput. Commun., vol. 4, no. 3, pp. 196–200, 2023, https://doi.org/10.26855/acc.2023.06.018.
    19. J. Liu et al., “Application of Deep Learning-Based Natural Language Processing in Multilingual Sentiment Analysis,” Mediterr. J. Basic Appl. Sci., vol. 08, no. 02, pp. 243–260, 2024, https://doi.org/10.46382/MJBAS.2024.8219.
    20. Z. Xiong, L. Zeng, Y. Wu, J. Li, X. Yuan, and B. Mo, “Application of Deep Neural Networks Integrating Multimodal Information in Intelligent Question Answering Systems,” Proc. - 2024 3rd Int. Conf. Artif. Intell. Auton. Robot Syst. AIARS 2024, pp. 693–698, 2024, https://doi.org/10.1109/AIARS63200.2024.00131.
    21. Z. Chen, “Neural Language Models in Natural Language Processing,” Proc. - 2023 2nd Int. Conf. Data Anal. Comput. Artif. Intell. ICDACAI 2023, pp. 521–524, 2023, https://doi.org/10.1109/ICDACAI59742.2023.00104.
    22. S. Sruthi, V. G. Trinath, V. Jayanth, V. P. Balaji, T. Singh, and A. Mandal, “Natural Language Processing for Sentiment Analysis with Deep Learning,” 2024 3rd Int. Conf. Innov. Technol. INOCON 2024, pp. 1–6, 2024, https://doi.org/10.1109/INOCON60754.2024.10511769.
    23. Q. Liu and X. Wang, “The application of deep Learning-Based natural language processing models in sentiment analysis,” 2024 5th Int. Conf. Electron. Commun. Artif. Intell., pp. 686–689, 2024, https://doi.org/10.1109/ICECAI62591.2024.10674860.
    24. G. Geddam, G. Dharmaraju, G. P. Kumar, M. Babu Ketha, and A. Lakshmanarao, “Exploring Deep Learning Approaches for News Classification with CNNs, RNNs and Transformers,” 2024 1st Int. Conf. Innov. Commun. Electr. Comput. Eng. ICICEC 2024, pp. 1–5, 2024, https://doi.org/10.1109/ICICEC62498.2024.10808249.
    25. B. Singh, A. Kumar, S. Kaur, S. Shekhar, and G. Singh, “Exploring the Effectiveness of Various Deep Learning Techniques for Text Generation in Natural Language Processing,” 2023 Int. Conf. Adv. Comput. Commun. Inf. Technol. ICAICCIT 2023, pp. 70–75, 2023, https://doi.org/10.1109/ICAICCIT60255.2023.10466068.
    26. L. Cao, “Sentiment Analysis of Social Media Text Based on Deep Learning,” 3rd IEEE Int. Conf. Mob. Networks Wirel. Commun. ICMNWC 2023, pp. 1–5, 2023, https://doi.org/10.1109/ICMNWC60182.2023.10435901.
    27. Prathyakshini and J. Shetty, “DeepText: Pioneering the Future of Text Classification with Innovative Deep Learning Techniques,” 5th Int. Conf. Electron. Sustain. Commun. Syst. ICESC 2024 - Proc., no. Icesc, pp. 911–917, 2024, https://doi.org/10.1109/ICESC60852.2024.10689751.
    28. E. al. P. Vijaya Lakshmi, “Advances in Sentiment Analysis in Deep Learning Models and Techniques,” Int. J. Recent Innov. Trends Comput. Commun., vol. 11, no. 9, pp. 474–482, 2023, https://doi.org/10.17762/ijritcc.v11i9.8831.
    29. M. Qiu et al., “EasyTransfer: A Simple and Scalable Deep Transfer Learning Platform for NLP Applications,” Int. Conf. Inf. Knowl. Manag. Proc., pp. 4075–4084, 2021, https://doi.org/10.1145/3459637.3481911.
    30. M. G, N. R.K, M. M, and S. V, “An enhanced framework for smart automated evaluations of answer scripts using NLP and deep learning methods,” Multimed. Tools Appl., 2024, https://doi.org/10.1007/s11042-024-19182-z.
    31. S. Purohit et al., “Analyzing two decades of media sentiments: NLP and deep learning insights into news bias and trends,” Iran J. Comput. Sci., 2025, https://doi.org/10.1007/s42044-025-00235-x.
    32. R. Sheik, K. P. Siva Sundara, and S. J. Nirmala, “Neural Data Augmentation for Legal Overruling Task: Small Deep Learning Models vs. Large Language Models,” Neural Process. Lett., vol. 56, no. 2, pp. 1–21, 2024, https://doi.org/10.1007/s11063-024-11574-4.
    33. M. F. Manzoor, M. S. Farooq, and A. Abid, Stylometry-driven framework for Urdu intrinsic plagiarism detection: a comprehensive analysis using machine learning, deep learning, and large language models, vol. 37, no. 9. Springer London, 2025. https://doi.org/10.1007/s00521-024-10966-w.
    34. M. A. Islam, F. Rabbi, and N. U. I. Hossain, “Performance evaluation of NLP and CNN models for disaster detection using social media data,” Soc. Netw. Anal. Min., vol. 14, no. 1, pp. 1–17, 2024, https://doi.org/10.1007/s13278-024-01374-y.
    35. P. Tüfekci and M. Bektaş Kösesoy, “Biological gender identification in Turkish news text using deep learning models,” Multimed. Tools Appl., vol. 83, no. 17, pp. 50669–50689, 2024, https://doi.org/10.1007/s11042-023-17622-w.
    36. A. Ba Alawi and F. Bozkurt, “Performance Analysis of Embedding Methods for Deep Learning-Based Turkish Sentiment Analysis Models,” Arab. J. Sci. Eng., no. X, 2024, https://doi.org/10.1007/s13369-024-09360-4.
    37. Y. Wang, M. Guo, X. Chen, and D. Ai, “Screening of multi deep learning-based de novo molecular generation models and their application for specific target molecular generation,” Sci. Rep., vol. 15, no. 1, pp. 1–15, 2025, https://doi.org/10.1038/s41598-025-86840-z.
    38. M. R. R. Rana, A. Nawaz, S. U. Rehman, M. A. Abid, M. Garayevi, and J. Kajanová, “BERT-BiGRU-Senti-GCN: An Advanced NLP Framework for Analyzing Customer Sentiments in E-Commerce,” Int. J. Comput. Intell. Syst., vol. 18, no. 1, pp. 1–18, 2025, https://doi.org/10.1007/s44196-025-00747-1.
    39. M. O. Raza et al., “Reading Between the Lines: Machine Learning Ensemble and Deep Learning for Implied Threat Detection in Textual Data,” Int. J. Comput. Intell. Syst., vol. 17, no. 1, 2024, https://doi.org/10.1007/s44196-024-00580-y.
    40. T. Martín-Noguerol, P. López-Úbeda, A. Pons-Escoda, and A. Luna, “Natural language processing deep learning models for the differential between high-grade gliomas and metastasis: what if the key is how we report them?,” Eur. Radiol., vol. 34, no. 3, pp. 2113–2120, 2024, https://doi.org/10.1007/s00330-023-10202-4.
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    Othman , R. S. ., & Ibrahim , I. M. . (2025). Deep Learning for Natural Language Processing: A Review of Models and Applications. International Journal of Scientific World, 11(2), 71-78. https://doi.org/10.14419/t1xnaq87