Richard E. Frye

Internal consistency reliability of the fractionated and whole University of Pennsylvania Smell Identification Test

The internal consistency reliability (ICR) of the 40-item University of Pennsylvania Smell Identification Test (UPSIT) and its 10-, 20-, and 30-item fractions was explored, as well as the relationships between the fractions and the entire 40-item test. Pearson correlation coefficients (rs) were computed among all independent combinations and permutations of the four 10-item UPSIT booklets using data from 774 subjects. The median r values of the 10- and 20-item combinations were used to establish the ICRs of the 10- and 20-item tests. The ICRs of the 30- and 40-item tests were estimated using the Spearman-Brown formula and the medianrs of the 20-item combinations. Additional ICR estimates of the 40-item UPSIT were obtained from nonsymmetrical fractions using the Horst formula. The ICRs for the UPSIT and its 10-, 20-, and 30-item fractions were 0.922, 0.752, 0.855 and 0.898, respectively. No major sex differences emerged. Estimates of correlations between (1) single booklets and two-booklet combinations and (2) the 40-item UPSIT using Guilford’s (1953) correction for nonindependence ranged from 0.812 to 0.871. Overall, these results indicate that (1) the UPSIT and its 10-, 20-, and 30-item fragments have very high ICRs and (2) individual UPSIT booklets or their combinations can be used to assess smell function in a reliable manner where extreme time constraints are present (e.g., in surveys and in brief neuropsychological test batteries).

Olfactory function in chemical workers exposed to acrylate and methacrylate vapors.

An investigation of the olfactory function of 731 workers at a chemical facility which manufacturers acrylates and methacrylates was undertaken using a standardized quantitative test. In a cross-sectional analysis of the data, no associations of chemical exposure with olfactory test scores were observed. A nested case-control study designed to evaluate the cumulative effects of exposure on olfactory function, however, revealed elevated crude exposure odds ratios (95% confidence interval) of 2.0 (1.1, 3.8) for all workers and 6.0 (1.7, 21.5) for workers who never smoked cigarettes. Logistic regression analysis, adjusting for multiple confounders, revealed exposure odds ratios of 2.8 (1.1, 7.0) and 13.5 (2.1, 87.6) in these same groups, respectively, and a dose-response relationship between olfactory dysfunction and cumulative exposure scores--semi-quantitative indices of lifetime exposure to the acrylates. The data also revealed decreasing exposure odds ratios with increasing duration since last exposure to these chemicals, suggesting that the effects may be reversible.

Olfactory function in young adolescents with Down's syndrome.

Decreased ability to smell is present in adults with Downs syndrome, many of whom are known to have brain pathology analogous to that seen in Alzheimers disease. Because olfactory loss is well documented in Alzheimers disease, the question arises whether young adolescents with Downs syndrome, who have no clear Alzheimers disease-like neuropathology, also exhibit olfactory dysfunction. To consider this issue, standardised tests of odour discrimination and identification were administered to 20 young adolescents with Downs syndrome (mean age (SD) 13.89 (1.98) years) and their test scores were compared with 20 mentally retarded and 20 non-mentally retarded control subjects matched to the patients with Downs syndrome on the basis of cognitive ability. No significant differences in olfactory function were found among the three study groups. These findings, along with those from studies of olfactory function in older patients with Downs syndrome, suggest that Downs syndrome related olfactory dysfunction occurs only at ages when Alzheimers disease-like pathology is present.

Human odor intensity perception: correlation with frog epithelial adenylate cyclase activity and transepithelial voltage response

Although a number of odorants are hypothesized to depolarize frog olfactory receptor cells by binding to ciliary glycoproteins which activate membrane-bound G-proteins to induce adenylate cyclase-mediated increases in intracellular cAMP (cyclic adenosine 3,5-monophosphate), it is not known whether these odorants influence human odor perception via similar mechanisms. In this paper we present evidence derived from odor attribute ranking and multidimensional scaling procedures that the perceived intensity of such odorants to humans is correlated with (a) the amount of adenylate cyclase activity they induce in an in vitro frog olfactory cilia preparation and (b) the magnitude of their influence on the frog transepithelial voltage response or electro-olfactogram (EOG). These observations are in accord with the hypothesis that the perception of the intensity of some odors by humans is associated with cAMP-related epithelial processes and imply that remarkable homologies exist between the intensity-related olfactory receptor mechanisms of frog and man.

Bilateral and Unilateral Olfactory Sensitivity: Relationship to Handedness and Gender

Unlike most major sensory systems, the majority of olfactory projections are ipsilateral. Both hemispheres can process olfactory information in a manner analogous to what is seen in other sensory systems, although, as noted below, they may do so differently. Gordon and Sperry (1969) found that patients whose corpus callosum and other forebrain commissures were surgically sectioned could only names odors presented to the left nostril; odors presented to the right nostril could be identified by pointing to an object associated with the smell.

The Influence of Ultradian Autonomic Rhythms, as Indexed by the Nasal Cycle, on Unilateral Olfactory Thresholds

Cyclic side-to-side variations in the autonomic tone of the nasal mucosae produce corresponding changes in nasal patency. This 90 minute to 4 hour “nasal cycle” is correlated with a number of ultradian rhythms, including asymmetries in left:right cerebral EEG activity and differential performance on visual/spatial psychological tasks (Eccles, 1978; Klein et al., 1986; Werntz et al., 1984). Several authors have proposed that the nasal cycle is part of an overall physiological rhythm known as the Basic Rest-Activity Cycle (BRAC). Thus, relatively greater airflow through the left nasal chamber is associated with the ‘REST’ phase of the BRAG and relatively greater airflow through the right nasal chamber is associated with the ‘ACTIVITY’ phase of the BRAC. During the ‘REST’ phase of the BRAC there is a preponderance of right hemispheric EEG activity, a spatial cognitive mode, and a parasympathetic predominance in the stomach, intestines, and other unpaired body organs. During the ‘ACTIVITY’ phase of the BRAG, greater left EEG hemispheric activity, a verbal cognitive mode, and sympathetic predominance in unpaired organs occurs (Kennedy et al., 1986).

A comparison of response characteristics of airflow and pressure transducers commonly used in rhinomanometry

Although the ranges in which pneumotachographs evidence linear output to static flows are documented in the literature, output reliability or the stability of calibration functions resulting from the input of dynamic nonsinusoidal flows (such as those which occur during nasal breathing) have not been investigated. Furthermore, it is not known whether the type of requisite pressure transducer used in conjunction with the pneumotachograph influences the pneumotachographs linearity, output reliability, or dynamic response. To provide information on these points, the authors determined the dynamic and static responsiveness of three pneumotachographs commonly used in rhinomanometry, in combination with three requisite pressure transducers. Experimental data indicate that: (a) output reliability depended on the pneumotachograph-pressure transducer combination and was not readily predictable from the reliabilities of the individual components, (b) heating increased pneumotachograph reliability, and (c) differences in accuracy existed among transducer combinations of high, but not low, flow frequencies.<<ETX>>

A comparison of mathematical models of nasal pressure-flow data and the contribution of compliant and inertial parameters

The fit of two mathematical models to nasal pressure-flow data from subjects with normal and pathological nasal airways is examined. The use of compliance and inertance parameters within these equations was assessed. Results indicate that the right hyperbolic and Rohers equation models gave analogous fits, and that the compliance and inertance parameters which are related to nasal pathology significantly increased the R/sup 2/ value of the fits.<<ETX>>

Mathematical models of the nasal airway: ability to discriminate between normal and abnormal static resistive components

Data from subjects with normal and partially obstructed airways were used to compare the goodness of fit and sensitivity to abnormal air flow from Rohrers equation and a right hyperbolic equation. The two goodness of fit measures used (adjusted R/sup 2/ and standard error of the estimate) indicate that the right hyperbole did not fit the data significantly better than Rohrers equation. Only parameters derived from Rohrers equation could discriminate between the normal and partially obstructed airways.<<ETX>>