Electrophysiological investigation of associative and non‐associative memory odours

As individuals explore their environment, they experience smells and recall memories associated with them. This close relationship between smell and memory has been extensively studied; however, less attention has been paid to the direct comparison of associative and non‐associative memory odours. This study aimed to measure responses to odours related to memories and responses to odours related to none or few memories using electroencephalography. In a within‐subject design, 25 individuals received two food odours (chocolate and apple strudel) while olfactory event‐related potentials (oERP) were recorded. These stimuli were chosen because individuals had an autobiographical memory associated with either one of the odours. Additionally, individuals rated the characteristics of the odours and were tested on their memory capacity. The results indicate that apple strudel, but not chocolate, produced larger oERP amplitudes when associated with a memory. Additionally, the apple strudel odour was found to be less pleasant and familiar than the chocolate odour, and fewer individuals had an association with the apple strudel odour. This indicates that oERP can be used to indicate the strength of odour‐related memories. Event‐related potentials were able to measure the comparative strength of an associative (AM) and a non‐associative memory (nAM) odour. A salient or unpleasant odour attached to a memory had a stronger signal than a more commonly encountered, pleasant odour.