## 4 Experiments
### Result Analysis
#### 4.5.1 Pattern Analysis  
The log-average spectrum is a method for processing PSD, simplifying spectral analysis through logarithmic treatment and making subtle variations more recognizable. This technique allows for a comprehensive and clear presentation of a signal's frequency domain characteristics, such as frequencies, peak values' total power and band power, serving as a powerful tool for in-depth signal understanding. Figure 6 shows the log-average spectrum across different frequency bands for each age group, measured on 19 electrodes. Our study reveals distinct differences in brain activity between young and older adults; older individuals exhibit lower frequencies and power in the \(\delta\), \(\theta\), and \(\alpha\) bands, while \(\beta\) band power is comparatively higher. 1. Young Adulthood (18-25)  
Specifically, individuals aged 18 to 25 displayed an average \(\alpha\) frequency of around 10.5 Hz, alongside robust power within the alpha band. In contrast, for those aged 50 and above, the peak \(\alpha\) frequency decelerated to an average of 9.56 Hz, with diminished band  
Figure 6: Log-average spectrum for age groups across various frequency bands (19 electrodes). power. Notably, there is an overall reduction in alpha band power with advancing age. The close association of \(\alpha\) waves with cognitive functions such as attention, learning, and memory indicates that the brain is undergoing rapid development at this stage, marking the transition from immaturity to maturity. 2. Middle Age (25-50)  
In individuals aged 25 to 35, EEG recordings indicate subtle shifts, characterized by a slight decline in \(\theta\) and \(\alpha\) wave activities. However, between the ages of 35 and 50, these changes become more pronounced, with a continued decrease in \(\theta\) and \(\alpha\) activities and a noticeable increase in \(\beta\) wave activity. 3. Senior Years (50+)  
In individuals aged 50 and above, both the frequency and power of \(\theta\) waves significantly decrease, indicating a downward trend in \(\theta\) wave resting-state activity from ages 18 to 68. Overall, the amplitude of brainwaves, specifically the total power, markedly reduces, with diminished \(\alpha\) wave activity, leading to a general slowdown in brain activity. Studies have shown that the power of alpha waves is closely related to attention, memory processing, and overall cognitive health. The reduction in alpha wave power in older adults may reflect a general decline in these cognitive functions. Conversely, reduced alpha activity may signal heightened experience levels, enabling seniors to transition between engagements more efficiently and swiftly. This discovery is supported by [PERSON] and colleagues' research (2021) [38]. These changes in older adults compared to younger adults may reflect a reallocation of neural resources and an ability to adapt to environmental changes. Additionally, alpha synchrony may help in deselecting a stronger but currently irrelevant neural ensemble, allowing the weaker but relevant ensemble to be boosted, as suggested by research on neural oscillatory synchronization [39]. We observed an increased relative power of \(\beta\) waves in older adults. This could stem from their wealth of life experiences, wherein a single input may trigger a cascade of \"pretrained\" memories. A study indicates that beta activity is related to attentional top-down modulation, which is crucial for processing memories and experiences. Beta synchrony is associated with the selection of relevant neural ensembles, further supporting the idea that increased beta activity in older adults might reflect their extensive life experiences [39]. Additionally, the concept of reminiscing and its therapeutic benefits are well-documented, highlighting how reflecting on past experiences can activate memory networks and enhance cognitive functioning [40]. Another study showed a phenomenon associated with motor control and inhibitory activity within the motor cortex.