Odor molecules stimulate receptors in the nose when a scent is detected. Signals travel to the olfactory bulb and onward to brain regions that identify, interpret and assign significance to smells.
The olfactory system stands out due to its direct links with the hippocampus and amygdala, structures central to memory and emotion. Research cited in the National Library of Medicine by Herz (2016) notes that the primary olfactory cortex connects closely to these areas, allowing an odor to engage the amygdala-hippocampal complex. The same work indicates that memories triggered by smells are typically more emotional and vivid than those prompted by images or words.
Although sight and sound can also elicit memories, smells often surface unexpectedly. Recognition of the associated memory follows the initial perception of the odor.
