Odor recognition memory as a function of odor-naming performance.

A series of experiments sought to clarify the relationship between odor naming and memory by manipulating odor label availability during a dual naming-memory task. Experiment 1 demonstrated that recognition memory and odor naming were both better when the naming task provided participants with odor label alternatives. Consistent and correct odor naming was associated with nearly perfect memory, whereas inconsistent or incorrect naming was associated with very weak memory if any at all. Experiment 2 showed that the availability of odor labels was effective at improving memory only if labels were available at both memory encoding and retrieval, suggesting that the labels were aiding memory by improving the identification of the odors. Odor naming was manipulated in Experiment 3 by varying the number of available labels from 4 to 16 during each odor-naming trial. As found in the previous experiments, naming and memory were strongly related in each of the labeling conditions. Experiment 4 showed that corrective naming feedback produced better memory performance but only when the feedback led to correct odor naming. It was concluded that perceptual processes related to matching olfactory input to acquired, multidimensional representations of odors play a critical role in both odor naming and episodic memory.

Characterization of the sniff magnitude test.

OBJECTIVE: To evaluate the potential utility of the Sniff Magnitude Test (SMT) as a clinical measure of olfactory function. DESIGN: Between-subject designs were used to compare the SMT and University of Pennsylvania Smell Identification Test (UPSIT) in study participants from a broad range of ages. SUBJECTS: A total of 361 individuals from retirement communities and an urban university and patients from an otolaryngology clinic. INTERVENTION: Study participants completed the SMT and UPSIT using standard procedures. MAIN OUTCOME MEASURES: The UPSIT was scored using standard procedures to calculate the number of correctly identified odors; a score that can range from 0 to 40 correct. The measure of olfactory function generated by the SMT is the "sniff magnitude ratio," defined as the mean sniff magnitude generated by the odor stimuli divided by the mean sniff magnitude to nonodorized air blanks. RESULTS: The SMT generally showed good agreement with UPSIT diagnostic categories, although SMT scores were only modestly elevated in the mild and modest hyposmia range of the UPSIT. Age-related decline in olfactory ability was evident on the UPSIT at younger ages than that seen with the SMT. As predicted, otolaryngology patients with olfactory complaints were found to be impaired on both the UPSIT and SMT. CONCLUSIONS: The SMT provides a novel method for evaluating the sense of smell that shows good general agreement with the UPSIT. Its minimal dependence on language and cognitive abilities provides some advantages over odor identification tests. There is some indication that the UPSIT may be more sensitive to olfactory (and/or nonolfactory) deficits. We conclude that sniffing behavior can be exploited for the clinical evaluation of olfaction. A comparison of performance on odor identification and sniffing tests may provide novel insight into the nature of olfactory problems in a variety of patient populations.