Responses of the Rat Olfactory Epithelium to Retronasal Air Flow

Responses of the rat olfactory epithelium were assessed with the electroolfactogram while odorants were presented to the external nares with an artificial sniff or to the internal nares by positive pressure. A series of seven odorants that varied from very polar, hydrophilic odorants to very nonpolar, hydrophobic odorants were used. Although the polar odorants activated the dorsal olfactory epithelium when presented by the external nares (orthonasal presentation), they were not effective when forced through the nasal cavity from the internal nares (retronasal presentation). However, the nonpolar odorants were effective in both stimulus modes. These results were independent of stimulus concentration or of humidity of the carrier air. Similar results were obtained with multiunit recordings from olfactory bulb. These results help to explain why human investigations often report differences in the sensation or ability to discriminate odorants presented orthonasally versus retronasally. The results also strongly support the importance of odorant sorption in normal olfactory processes.

Neural Response Time of Stutterers and Nonstutterers in Selected Oral Motor Tasks

Neural response time (NRT) was compared for 12 adult stutterers and 12 matched normal speakers on two verbal tasks (production of /pæ/ and /bæ/) and one oral, nonverbal task (lip closure) in response to visual and auditory stimulation. The auditory response stimulus was presented separately to the left and right ears, and the visual stimulus to both eyes. NRT was defined as the time interval between stimulus offset and the onset of electromyographic (EMG) activity from orbicularis oris superior muscle. Results show, in general, that stutterers are slower in NRT for all response tasks in both stimulus modes. Significant differences were found, however, for only the auditory mode. Analyses of the differences between and within groups for response tasks and stimulus modes are discussed in terms of recent research in and theory of timing disturbances in stuttering.

Descriptive Statistics for Two Children's Social Desirability Scales, General and Test Anxiety, and Locus of Control in Elementary School Children

As part of a larger study of articulatory deviant children, 5 personality instruments were administered to 671 children in Grades 1 through 5 in 7 public schools. Complete descriptive statistics on grade by sex samples, analyses of variance for grade by sex by school effects, test-retest coefficients, and intercorrelations are presented. Comparison of the descriptive data and published norms suggests that investigators should give serious consideration to possible influences of stimulus modes, response modes, and examiner behaviors on children's self-report scores for these constructs. Inter- and intra-scale characteristics look promising for multivariate analyses of the role of these constructs as trait, moderator, or suppressor variables in predicting articulation improvement with or without speech therapy.