Olfactory Imagery and Repetition Priming

Abstract

This study examined the impact of odor naming and imagery ability on the capacity of female participants to form odor images, as indexed by a novel olfactory repetition priming task. Experiment 1 involved three conditions - olfactory and visual imagery priming, and a no-prime control. Odor imagery priming was only obtained in good odor namers. Experiment 2 used the same conditions, but altered the nature of the hit-rate trials to test how odor imagery might facilitate performance in good odor namers. Odor imagery priming was again obtained only in good odor namers and this effect appeared to result from generic activation of olfactory processing caused by trying to imagine a smell. Experiment 3 examined whether this latter effect might be generated semantically, but no evidence for this was obtained. Together, these findings suggest that trying to form an odor image can facilitate performance by producing a generic state of activation, which only benefits existing odor-name associations. While this effect is mediated via perceptual processes it may occur independently of a conscious image.

Human olfactory consciousness and cognition: its unusual features may not result from unusual functions but from limited neocortical processing resources

“…In fact Lyman and McDaniel (1990) are the only group to report a significant correlation between imagery and task performance, but this study has been criticized, as it is unclear whether the reported imagery performance was mediated by verbal codes (see Stevenson and Case, 2005). Other studies have failed to find any link with performance, including Lyman (1988), and Tomiczek and Stevenson (2009). The latter study explored in some detail the predictors of enhanced imagery performance.…”

“…The olfactory literature on these topics presents a far more complex and seemingly confusing picture. First, after decades of disagreement, it now appears that trying to imagine an odor does have several detectable consequences: (1) it activates brain regions, including primary processing areas, which are also active during real smelling (e.g., Djordjevic et al, 2005); (2) it improves various psychological capacities, such as enhancing the detection of threshold level odors (Djordjevic et al, 2004) and priming (Tomiczek and Stevenson, 2009); (3) it mimics various psychophysical parameters, relating to olfactory interactions, intensity and quality (e.g., Carrasco and Ridout, 1993); and (4) it generates olfactomotor responses (sniffing behavior) that closely approximate what is observed during actual smelling (e.g., Bensafi et al, 2003). While, a number of studies have failed to find improved psychological capacities (e.g., Crowder and Schab, 1995) or mimicking of psychological effects observed with real odors (e.g., Herz, 2000), the weight of evidence suggests that trying to imagine a smell can influence a variety of psychological, physiological and neural variables, in much the same way as actual smelling can.…”

Same same but different: the case of olfactory imagery

“…The results showed that odors that were difficult to name also were difficult to imagine and that prior learning of the odor names exerted a positive effect on imagery capacity. Moreover, Tomiczek and Stevenson (2009) reported that odor imagery priming was prevalent only among good odor namers and appeared to be the result of a generic activation of olfactory neural networks when the participants tried to form an odor image. Importantly, Tomiczek and Stevenson (2009) suggested that this could occur in dependently of any consciously reported olfactory image.…”

Smelling phenomenal

“…However, a more recent set of experiments (Tomiczek and Stevenson, 2009) calls this into question and argues that the same perceptual state is not elicited, rather similar structures that are utilized for olfactory perception in general are activated. Tomiczek and Stevenson (2009) assert that we do not imagine a specific odor, rather there is a general overall increase in activation across areas in the olfactory system that are responsive to odorants similar to the imagined odor.…”

“…Tomiczek and Stevenson (2009) assert that we do not imagine a specific odor, rather there is a general overall increase in activation across areas in the olfactory system that are responsive to odorants similar to the imagined odor. While their results indicate that the imagine state does not have the same exact content it does focus us in the right direction.…”