## 4 Discussion
The left inferior fronto-temporal region was identified as the brain region that, in comparison to normal words, appears to contain neural circuits representing quantities. It is noteworthy that this region exhibited higher brain activity in response to number words compared to normal words, though not to the same extent as in response to digits. These activity differences were statistically proven and are clearly visible through visual inspection of the respective ERPs (see Figure 2). This suggests that number words are less effective in triggering ideas of quantities than digits. In order to gain insight into the spatio-temporal properties of number word versus digit processing, it is first necessary to examine the initial stages of the brain response, commencing shortly after the onset of the stimulus and continuing for approximately 400 ms. During this period, the left inferior fronto-temporal region, which is associated with the processing of numerical information, becomes activated in response to earlier brain activities starting more posterior in the brain. As early as approximately 230 ms after stimulus onset, the inferior parietal (or occipito-temporal or temporo-parietal) brain region exhibited the most negative-going brain potentials in response to digits compared to words, non-words, and number words. This response was right hemispheric-dominant (electrode location P8). This right hemispheric region may be considered to correspond to the Wernicke area [3] in the left hemisphere, which is well known for its specialisation in language comprehension (see introduction) [43]. Indeed, all word categories (words, non-words and number words) elicited comparable brain potentials in this region, whereas only digits (which lack any letters and are therefore not words) yielded distinct brain potentials (this difference is more pronounced in the right hemisphere). It may therefore be surmised that this brain region processes digits in a manner that differs from that of other stimuli, potentially due to the absence of language-related semantic content inherent to a digit (or series of digits) [44; 45; 46]. Furthermore, non-words elicited slightly more negative-going brain potentials than actual words in this region. The aforementioned discrepancies, however, are not statistically significant (only tendencies), according to the results of the \(t\)-test. Nevertheless, they are discernible, at the very least, in descriptive terms. Quite remarkably, [PERSON] et al. [47] designed and conducted an event-related (functional) near-infrared spectroscopy (fNIRS) experiment to measure differences in brain activity in 6-month-old infants related to number processing. The researchers identified a right parietal specialisation for number processing, which is notable given that this appears to be a specialisation that occurs before or concurrently with language development. This finding aligns with the observations presented in the introduction. Number processing is not contingent on language processing. In a separate functional magnetic resonance imaging (fMRI) study, the authors observed that letters activated the left hemisphere's mid-fusiform and inferior temporal cortical regions, while numbers elicited activity in a right hemisphere lateral occipital area [48]. The results of our study indicated that the processing of digits involved bilateral occipto-parietal regions, with a notable right hemispheric dominance, which can be seen in the respective topographical map in Figure 3. Therefore, this finding aligns with the prior results mentioned above. Additional studies have demonstrated that left and/or right cortical activity increases in response to visual number presentations in analogous regions, namely the occipitotemporal and temporo-parietal areas [33; 49; 50]. As previously stated, the location of the initial effect identified in our study encompasses the Wernicke area, which is well-established in the literature.