How does memory work in the brain?

Encyclopedia of Opinion

Question: How does memory work in the brain?
Position‹5 of 5: Memory is strongly effected by our senses
Argument: Smell and memory

Our sense of smell is intimately linked with the memory mechanisms in our brains.

The argument

Smell has an unusually direct hold on memory, and the argument offered here explains that in two stages: first why such a link would have been selected for, and then what in the brain's layout makes it possible. The evolutionary case comes first. A strong memory of sense of smell gave an advantage to our ancestors, because in the wild a smell is often the earliest available information about something that matters. A scent can advertise a dangerous food item or a predator; it can also identify safe foods, or a potential mate. In each case the value lies not in detecting the smell but in remembering what happened the last time it was encountered — an odour that carries no recollection of its consequences is of little use. Because remembering the experiences associated with smell conferred that advantage, we evolved a connection between our memory systems and our olfactory system. The anatomical case explains how the connection is realised. The locations of smell, memory and emotional processing in our brain can explain this link. The olfactory bulb, where our brain processes smell, is located at the bottom of the brain and connects to the nose. Its position is significant: the bulb has direct connections to the amygdala and the hippocampus, the areas responsible for emotion and memory processing. Smell therefore reaches the structures that encode emotion and memory without the longer routing that other senses require. That architecture is what produces the familiar experience. Because the same signal arrives at the emotional and the memory systems together, a smell tends not to be recalled on its own but to bring back a scene and a feeling with it. The link between smell, emotions and memory is not a curiosity of introspection, on this account, but a consequence of where these systems sit in the brain and of the evolutionary pressure that put them in contact.

Premises

[P1]A strong memory for smell gave our ancestors an evolutionary advantage in identifying predators, dangerous food, safe food, and mates. [P2] This drove a connection between our olfactory and memory systems. [P3] The olfactory bulb sits beside and directly connects to the amygdala and hippocampus, the brain's emotion and memory centres. [C] Therefore, because smell is so tightly linked to recall, memory is strongly affected by our senses.

Counter-arguments

Smell and memory being linked is simply a coincidence. Smell simply helps stimulate memory, but there is nothing extra special about this connection. Auditory and visual cues help recall memories too, and our sense of smell is no different than these. In fact, we use our sense of smell for information encoding less than vision or hearing, so it is even less important than our other senses in regards to memory.

Rejecting the premises

[Rejecting P3] The interplay between smell and memory is no different than the interplay between our other senses and memory.