In recent years, many research papers in neuroscience have verified that there are two anti-correlated circuit networks in the brain: one network is appropriate for an art-oriented way of thinking; the other is appropriate for a mathematical way of thinking. Being anti-correlated these two networks are not actively processing at the same time, or at least one is dominant while the other is subordinate at any given point in time.
It is therefore logical to expect that if a student has been involved in artistic thoughts or activities immediately before going to their math class, it will be difficult, at the beginning, for them to switch to thinking mathematically. And conversely, It will be difficult for a student to immediately switch their way of thinking when going from a math class to an art class.
Consequently, the teacher should spend a few minutes at the beginning of their respective class to do warmup exercises which will help the students get into the "groove" that is appropriate for the subject being taught.
Doing this may save some students, who would otherwise feel disconnected, from having a distaste for math or for art.