Memories associated with smells are not particularly vivid or emotional

Smell is often considered to be a particularly evocative sense: just think about the vivid memories brought to life by the haunting scent of an ex's perfume or the smell of a treasured childhood toy.

Previous research has indeed suggested that smells can evoke particularly vivid and complex autobiographical memories. But most of this research has relied on the active presence of a smell in order to elicit these memories. It's not clear then whether these memories are particularly emotional because of the presence of the smell cue, or whether all memories associated with smells are highly emotional.

Now, in a paper in Acta Psychologica, a team led by Luisa Bogenschütz from the University of Hildesheim finds that memories associated with smells are not any more vivid or emotional than memories associated with other senses.

In the first two studies, participants provided five written descriptions of autobiographical memories, one associated with each of the five senses (touch, sight, smell, sound, and taste). They indicated when the event occurred, how much they felt brought back to the event, how emotionally intense, pleasant and vivid the memory was, and how often they thought of the memory and how quickly they were able to recall it. In the first study, participants recalled any autobiographical memory they could think of for each sense; in the second, they were asked to recall an important autobiographical memory.

The final study used diary entries to explore autobiographical memories and senses. Every evening for two weeks, participants recorded one autobiographical memory they had recalled during that day. First, they wrote a summary of the memory, noted when the original event had happened and rated the memory on some of the same measures used in the first studies. However, they were not asked to think of memories associated with specific senses – instead, they simply indicated which of the senses were present in the memory, and how important they were to it.

In the first study, there was no significant difference between smell-related memories and non-smell related autobiographical memories in terms of being brought back to the event – though in study two, memories associated with sounds brought people back to the original event more than those related to smell. Smell-related memories were also rated as less emotional than sound or sight-related memories, and there was no difference in terms of intensity and vividness. Smell-related memories were also regarded as less pleasant than those related to other senses in the first study. Finally, participants thought about smell-related memories less frequently than those related to sound, but no more or less than those related to taste, touch, or sight.

These results do not necessarily contradict previous research that found especially strong feelings brought back in response to smell. Those studies used smells to evoke memories, while the new study looked at memories associated with them. This suggests that smells can evoke particularly strong feelings in the moment, but that memories associated with smells aren't stored in a way that always brings back strong feelings.

The research suggests clear differences between looking at memories elicited by smells and memories associated with smells. Exploring the differences between the two could be interesting for future research: why are memories merely associated by smells rather than elicited by them different in terms of how frequently we recall them and how we experience them?