# Mind, Machine, and Meaning: Cognitive Ergonomics and Adaptive Interfaces in the Age of Industry 5.0
## 3 Ergonomic Techniques in Human-Machine Interactions
### Methodological Frameworks in HRA
#### 3.2.4 Eye-Tracking and EEG-Based Techniques in Ergonomic and Cognitive Research  
In recent years, advancements in neurophysiological technology have enabled researchers to objectively evaluate human behavior and mental states through tools such as electroencephalography (EEG) and eye-tracking (ET). These methods provide a more accurate and non-invasive approach to studying cognitive processes, overcoming the limitations of subjective questionnaires or verbal feedback [75; 76]. Their application in ergonomics, user experience, human-computer interaction (HCI), and Industry 5.0 environments is growing, especially in tasks requiring attention monitoring, stress assessment, and decision-making analysis [77]. Overview of EEG Technologies  
Electroencephalography (EEG) is a method for monitoring brain activity through electrodes positioned on the surface of the scalp. It is known for its high temporal resolution, making it suitable for the real-time monitoring of mental states such as attention, fatigue, or cognitive load [75; 78]. EEG frequency bands reflect different cognitive or emotional states (Table 4). Specific components, such as Event-Related Potentials (ERPs), are often used to analyze responses to stimuli. For example, alpha desynchronization and theta synchronization are both used as markers of an increased cognitive load [79]. Overview of Eye-Tracking Technologies  
Eye-tracking technology records fixation, saccades, and gaze trajectories to understand visual attention and interaction (Table 5). It helps determine where, when, and how long a person looks at specific areas, making it ideal for product design, interface usability, and mental workload estimation [77]. While eye-tracking reveals visual behavior, it does not capture internal cognition. Hence, the combination of EEG and ET yields deeper insights [75; 77]. Integrated EEG and Eye-Tracking Research  
Studies show that combining EEG with ET offers a multimodal understanding of user experience by aligning eye gaze with concurrent brain responses [77; 78]. This fusion allows researchers to  
* Detect emotional and cognitive states in real time;
* Quantify mental workload during complex tasks;
* Improve HCIs by customizing feedback based on user states. [PERSON] & [PERSON] [75] highlight that EEG and ET integration improves the interpretability of gaze data and strengthens conclusions about the underlying thought processes. [PERSON] et al. [76] emphasize that in Industry 5.0, EEG (used in 45% of neurophysiological studies) and ET (30%) are critical for human-centric interface and system design. \begin{table}
\begin{tabular}{c c c} \hline
**Band** & **Frequency (Hz)** & **Associated State** \\ \hline Delta & \textless{}4 & Deep sleep \\ \hline Theta & 4–8 & Drowsiness, cognitive effort \\ \hline Alpha & 8–12 & Relaxation, alertness \\ \hline Beta & 13–30 & Active concentration \\ \hline Gamma & \textgreater{}30 & High-level cognition \\ \hline \end{tabular}
\end{table} 
Table 4: EEG frequency bands reflecting different cognitive or emotional states [75]. \begin{table}
\begin{tabular}{c c} \hline
**Metric** & **Significance** \\ \hline Fixation Duration & Indicates cognitive processing [77] \\ \hline Number of Fixations & Related to the attention distribution [77] \\ \hline Saccade Velocity/Amplitude & Associated with cognitive effort or stress [77] \\ \hline Heat Maps and AOIs & Highlight key areas of visual attention [77] \\ \hline \end{tabular}
\end{table} 
Table 5: Eye-tracking technology. Applications in Ergonomics and Industrial Design  
The integration of EEG and eye-tracking technologies has enabled researchers to gain a clearer view of the ways users interact with designed systems, interfaces, and spatial environments in various applied contexts. In the field of product evaluation and aesthetics, these tools reveal both visual attention patterns and the underlying neural responses associated with user preferences, enabling the optimization of product designs for enhanced appeal and usability.