The present study reports normative ratings for 200 food and non-food
The present study reports normative ratings for 200 food and non-food odors. response. The suitability of these data for use in future olfactory study is considered, and effective implementation of the data for controlling stimuli is discussed. assessment of name-ability, there is limited control on the psychological characteristics of the odors. These odor characteristics may be of importance in determining cross-modal serial position function congruence, since the psychological distinctiveness of items (a somewhat ill-defined construct that can be influenced by perceptual buy 34597-40-5 familiarity) is argued to affect both the primacy and recency components of the serial position curve (Hay et al., 2007). One method by which the perceptual experience of odors can be assessed is from ratings of the odors across various dimensions. Judgments of this nature are typically obtained via subjective ratings pre-test (Yeshurun et al., 2008), during encoding (Larsson et al., 2004b), or after the experiment through data collection (Olsson et al., 2009). Indeed, there is some merit to collecting data this way, the most notable being mitigation of individual differences. For example, individual naming ability can allow tailored selection of odorants for use in subsequent memory and discrimination tasks (Rabin and Cain, 1984; Rabin, 1988). However, issues arise when tasks require novel presentation, and speeded encoding or recognition. In addition, these methods of odor stimuli categorization are often inconsistent, utilizing different scales and tasks, and resulting in these data rarely being used beyond the confines of the study in which they were collected. To this extent, the data are study-dependent. It is, therefore, desirable to have a reliable catalog of odors and normative data which will facilitate the use of odors in olfactory memory research. Accordingly, the present study attempts to provide data norms buy 34597-40-5 for a large set of commercially available odors, analogous to that produced for words (Coltheart, 1981), faces (Ebner et al., 2010), and objects (Yoon et al., 2004). Normative data in the verbal processing literature allows strict control of the orthographic, phonological, and psychological characteristics of words. An odor data analog will thereby enable researchers to both strictly control for, and manipulate, levels of psychological difference. There is some limited precedence for the use of normative data for olfactory stimuli. The University of Pennsylvania Smell Identification Test (UPSIT; Doty et al., 1984b) is a clinical test of olfactory ability and uses 40 microencapsulated scratch and sniff odorants within a standardized test of olfactory function. The creation of this test includes normative data for familiarity, pleasantness, intensity, and irritability, and has been used extensively in olfactory research (Nguyen et al., 2012). However, the UPSIT is a test of olfactory dysfunction, where normal olfactory buy 34597-40-5 function would see naming of these highly familiar odors at, or near, ceiling. Employment of such a stimulus-set would provide limited variability in terms of familiarity and, potentially, encourage a memory strategy utilizing verbal labels. An alternative is to use odorants from the MONEX-40 (Freiherr et al., 2012), a test designed to detect differences in olfactory identification abilities in a normal population. However, the normative ratings from this study again focus only on familiarity, intensity, and pleasantness, and are limited to a relatively small set of 40 odorants. Perhaps the closest attempt to a normative database for olfactory recognition tasks was reported by Sulmont et al. (2002). In this study, odors were rated in terms of familiarity, perceived complexity, and pleasantness by 24 French-speaking participants. Verbal identification was tested by selecting the name from PRKAR2 a 68-item forced-choice list. These ratings were used to generate two familiar and two unfamiliar recognition sets of 18 odors. Interestingly, some perceptual overlap between dimensions was found with a significant.