The “miracle” berry taste testing reminded me of a neuroscience paper published around 2005 on the encoding of taste receptors on our taste buds. At the time, there was still debate about whether or not we have a “tongue map” for all the different taste types, or whether each taste bud had multiple kinds of receptors. As part of their tests, I believe that the researchers used genetic knockouts (in mice) to switch the binding site of one of the taste types (ie, converting umami into sweet). At the time, I remember thinking that would be very useful because I have a sweet tooth and maybe I could convince my body that eating healthy vegetables was like eating candy. After reading the NY Times article on the “miracle berries,” I had high hopes, but I was disappointed.
The “miracle berries” made all acidic things taste cloyingly sweet: the vinegar, lemon, lime, grapefruit, kumquat, tomato. It made the grapes a little bit sweeter, too. It did not seem to affect the cheese or crackers.
Prior Associations vs New Associations (for acidic foods):
I have always enjoyed acidic foods: I will drink vinegar straight and I used to suck on limes until I learned that they destroy enamel. So, my past associations were pleasant. My new associations were pretty awful: everything tasted disgusting, like it had some kind of awful Splenda or fake sugar additive. If the lemons had tasted like candy lemons, maybe I would have a positive association, but instead it tasted fake and unnatural, like I was eating something possibly poisonous.