Familiarity influences odor memory stability

Abstract

It has been suggested that olfactory perception relies on a memory-based pattern-matching system. In this experiment, we tested a prediction derived from this approach, namely that representations of unfamiliar odors are less stable than those of familiar odors. Participants provided qualitative descriptions of odors either immediately after smelling them or after a 1-or 3-min delay. Later, participants were given a surprise test in which they were asked to match their earlier descriptions to those same odors. Delay exerted no effect on familiar odors. However, for unfamiliar odors, while their matching performance was equivalent to that for familiar odors when descriptions were made immediately, delay significantly impaired performance. The better capacity to name familiar odors only assisted matching performance at the longest (3-min) delay. These findings suggest that unfamiliar odors have less stable representations than do familiar odors. Pattern-matching theory suggests that this occurs because unfamiliar odors weakly activate many nodes in memory, resulting in less-stable percepts.

Item-specific proactive interference in olfactory working memory

“…As outlined earlier, it is possible that stimulus characteristic differences in respect to the distinctiveness of nameable and non-nameable odours, underpinned the difference (Mecklinger et al, 2003). It should be noted that our hard-toname odours are also less familiar (Moss et al, 2016), and representations for less familiar odours are argued to be less distinct with overlapping features (Stevenson & Mahmut, 2013a;Wilson & Stevenson, 2006). If the negative probe odours are less defined/distinct, it is possible that participants are less aware/confident that the current probe odour maps onto the representation for that same odour in the preceding trial (the RN probe) (an account outlined by Mecklinger et al, 2003).…”

“…Since unfamiliar odours are described as 'fuzzy' percepts with overlapping features (Stevenson & Mahmut, 2013a;Wilson & Stevenson, 2006), it is possible that this lack of stimulus distinctiveness may have prevented PI. As described earlier, Mecklinger et al (2003) argues that for less distinct stimuli, the mapping in memory between the original presentation of the item and its re-presentation as the negative probe is less clear, and, as a result, the level of PI for that item is reduced.…”

Olfactory working memory: exploring the differences inn-back memory for high and low verbalisable odorants

“…Alternatively, the memory advantage for the verbalisable odorants might be explained by the high verbalisable odorants having greater familiarity for the participant (Moss et al, 2016, report a strong positive correlation between verbalisability and familiarity: r = .88). Indeed, it has been proposed that exposure to familiar odorants activates more specific olfactory representations in memory compared to unfamiliar odorants (Stevenson & Mahmut, 2013b;Wilson & Stevenson, 2006). It follows that more specificity in the olfactory representation would lead to less confusion in memory judgments due to high verbalisable odorants being more perceptually discrete.…”

Evaluation of omission testing as a method for identifying important odorants in a mixture

“…To discriminate between a given odor mixture and others with similar olfactory receptor neuron (ORN) patterns, training is necessary. Stevenson and associates (Stevenson & Mahmut, ; Stevenson & Wilson, ) demonstrated that familiar patterns of ORN activity, which are stored in memory, are activated during discrimination tasks. Their research suggested that successful discrimination depends on matching incoming patterns with those stored in memory.…”