# Memory Model for Morphological Semantics of Visual Stimuli Using Sparse Distributed Representation
## 4 Experimental Results
### Experiment 1: Memory Pattern Formation Experiment without Pre-Memory Process  
The first experiment assumed that there is no initial memory of the image, and then sequentially entered the image one by one to form a memory. Images used for input are sequentially fed into the memory model with 10,000 test sets of the MNIST data set. Figure 15 shows an example of a memory pattern formed when images are input one after another. When the label '7' image is fed as the first input, it is registered as memory pattern 1 because there is no previously saved memory. When the label '2' image is fed as the second input, the similarity is compared with the stored memory pattern 1, and since the similarity does not exceed the threshold, it is registered as a new memory pattern 2. This process repeats the above process whenever a new image comes in. When the label '1' image comes in as the sixth image in the picture, the existing memory pattern 3 is updated because the similarity to the existing memory pattern 3 exceeds the criteria. The above process is iteratively performed for 10,000 test images. Table 1 shows the number of generated memory patterns when SDR's active bit overlap is applied as a similarity comparison criterion for image input of 10,000 test images and is visualized in Figure 16. The degree of overlap is varied from 20% to 60%, and if the SDR similarity does not exceed this ratio, it is saved as a new memory pattern. If the SDR overlap rate for judging the similarity is applied high, the image showing a slight difference is judged as a different memory pattern, and the memory pattern increases rapidly. Figure 15: An example of forming an initial memory pattern without a pre-memory process. Each input image is converted into a unique SDR and then contributes to the update of the existing memory pattern or is registered as a new memory through similarity comparison with the stored memory pattern. As an example of the experimental results, when the similarity determination criterion is 20% active bit overlap, it is stored as 16 memory patterns when 10,000 test images are used. Since these figures exceed the expected range, additional analysis is conducted at the same time. In Figure 17, when 16 memory patterns are stored, the distribution of labels belonging to each pattern is indicated by color codes. Here, the horizontal axis is the number of each memory pattern, and the vertical axis is the total number of images belonging to each memory pattern and the labels constituting it are indicated by color codes. Ideally, a small number of labels are included in a single memory pattern. Some memory patterns have a small number of labels, so it can be said that memory patterns are well formed according to morphological semantics, but there have been many cases where they are not. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Overlap Rate** & **100 Images** & **1000 Images** & **3000 Images** & **5000 Images** & **10,000 Images** \\ \hline
20\% & 6 & 11 & 14 & 14 & 16 \\ \hline
30\% & 10 & 17 & 22 & 25 & 29 \\ \hline
40\% & 14 & 26 & 41 & 47 & 65 \\ \hline
50\% & 27 & 55 & 85 & 97 & 122 \\ \hline
60\% & 55 & 136 & 206 & 252 & 341 \\ \hline \end{tabular}
\end{table} 
Table 1: Number of memory patterns compared to SDR overlapping rate. Figure 16: Number of memory patterns according to SDR overlapping ratio and number of input images without pre-memory process. Figure 18 shows in which memory pattern the images of each label are distributed. Here, the horizontal axis represents the label number of the image used as an input, and the vertical axis represents the total number of each label and the ratio belonging to each memory pattern with 16 color codes. In the case of labels '3' and '6', it is judged that morphologically similar ones are relatively well patterned, but many labels are not stored in memory patterns according to morphological semantics. In other words, there should be a label indicating the dominant distribution in one memory pattern, but this distribution does not appear well and shows a mixed pattern.