Synesthesia is a phenomenon in which stimulation of the sensory organs causes other sensations of a completely different nature  It is the result of the interaction between different senses, and it is also a conditioned reflex phenomenon  Synesthesia is present in all senses and manifests in individual differences
In real life, because the appearance of a certain property of things is often accompanied by the appearance of another property of things, a fixed conditional connection is formed between the sensations caused by these two properties of things
Seeing the mobile phone number written on the paper, Xiao Feng felt numb