Some wonder if people with synesthesia are just being metaphorical, as many people use metaphors that cross sensory modalities. a "loud shirt" doesn't actually produce a sound, a "warm color" doesn't actually evoke a change in temperature, and "bitter cold" doesn't actually produce a taste. what does cytowic friend say that suggests this isn't the case

Synesthesia is a neurological condition that an individual experience which allows her or him to perceive stimuli using a sense that is normally not associated with the stimuli. For example, people with chromesthesia, a type of synesthesia, can hear sounds when a color comes up – for example, hearing a trumpet when they see a red apple. There are various other types of synesthesia, such as seeing alphabets and at the same time seeing colors associated to them or hearing words and feeling a skin sensation with each different words said.  

Since these experiences are unique to the individual who has the condition, Cytowic’s friend should come up with a demonstration so that Cytowic can experience the same thing he does.

the historians cited in the article all agree with one another about the cause of the civil war. despite coming from different backgrounds and cultures, the historians agree that slavery was the root cause of the civil war. the fact that all these historiansgenerally agree with one another makes their shared viewpoints more reliable and valid, especially because the historians have different backgrounds and all work for the well-respected institutions of howard university, clemson university, and the university of colorado.