Discriminating the stimulus elements during human odor-taste learning: a successful analytic stance does not eliminate learning

Odor "sweetness" may arise from experiencing odors and tastes together, resulting in a flavor memory that is later reaccessed by the odor. Forming a flavor memory may be impaired if the taste and odor elements are apparent during exposure, suggesting that configural processing may underpin learning. Using a new procedure, participants made actual flavor discriminations for one odor-taste pair (e.g., Taste A vs. Odor X-Taste A) and mock discriminations for another (e.g., Odor Y-Taste B vs. Odor Y-Taste B). Participants, who were successful at detecting the actual flavor discriminations, demonstrated equal amounts of learning for both odor-taste pairings. These results suggest that although a capacity to discriminate flavor into its elements may be necessary to support learning, whether participants experience a configural or elemental flavor representation may not.     

Failure to Obtain Reinstatement of an Olfactory Representation

It has long been suspected that attentional processes differ between olfaction and the other senses. Here, we test whether voluntary dishabituation, seen, for example, when we re‐attend to the ticking of a clock, can occur in olfaction. Participants were seated in an odorized room, where at various intervals they had to evaluate what they could smell. An experimental group had one nostril open and the other closed, except during the evaluations, so that the closed side was subject to centrally driven habituation, but not peripheral adaptation. A control group had both nostrils closed except during evaluations. Following exposure, the experimental group could not report the room's odor in either the centrally habituated nostril (i.e., that remained closed) or the nostril that remained open, while the control group could. This effect could result from a number of causes, including olfaction's unique neuroanatomy, functional constraints imposed by detecting volatile chemicals, and as a consequence of limited cortical resources, with implications for the functional value of consciousness.     

Validating the factor structure of the Self-Report Psychopathy scale in a community sample

Currently, there is no standard self-report measure of psychopathy in community-dwelling samples that parallels the most commonly used measure of psychopathy in forensic and clinical samples, the Psychopathy Checklist. A promising instrument is the Self-Report Psychopathy scale (SRP), which was derived from the original version the Psychopathy Checklist. The most recent version of the SRP (SRP-III; D. L. Paulhus, C. S. Neumann, & R. D. Hare, in press) has shown good convergent and discriminate validity and a factor structure similar to the current version of the Psychopathy Checklist (PCL-R; R. D. Hare, 1991, 2003). The analyses in the current study further investigated the viability of the SRP-III as a PCL-R-analogous measure of psychopathy in nonforensic and nonclinical samples by extending the validation process to a community sample. Using confirmatory factor analyses and logistic regressions, the results revealed that a four-factor oblique model for the SRP-III was most tenable, congruent with the PCL-R factor structure of psychopathy and previous research in which the SRP-III was administered to a student sample.     

Experience dependent changes in odour-viscosity perception

One consequence of experiencing flavour — the combination of taste, smell and somatosensation that occurs during ingestion — is that it can result in perceptual changes for the odour component, when this is later smelled alone. One such change is the acquisition of taste-like properties, but whether odours can also acquire somatosensory-like qualities is largely unknown. Participants here were exposed to one odour sampled in a viscous solution, another sampled in a sweet/viscous solution, and a further odour sampled in water. The odour sampled in the sweet/viscous solution was, when later sniffed alone, judged to smell thicker and sweeter, than the other two odours. Similarly, when the sweet/viscous paired odour was added to a viscous solution, the combination was judged as more viscous, than the other two odours — and sweeter when added to a sweet solution. This experiment suggests that odours can acquire tactile-like somatosensory qualities and this may best occur when a taste is present during learning. Recent work indicates that tastes may be superior to somatosensory stimuli alone in promoting flavour binding, a seeming precondition for this type of learning.     

Difficulty in evoking odor images: The role of odor naming

Many studies report that people have difficulty in evoking odor images. In this article, we explore whether this results from another commonly observed phenomenon, difficulty in naming odors. In Experiment 1, participants both named and attempted to imagine either odors or their common visual referents. More-difficult-to-name odors were reported as being more difficult to evoke as olfactory images, in comparison with the visual condition. In Experiment 2, participants received training prior to forming odor images and naming the same set of odors. As in Experiment 1, more-difficult-to-name odors were harder to imagine, but participants who had learned the odor names during training were significantly better, by their own report, at imagining many of these stimuli, relative to participants who were either exposed to the odors, exposed to their names, or who received no pretraining. In sum, these experiments suggest that odor naming may account for some of the difficulty reported by participants when attempting to evoke odor images; we discuss an associative basis for this effect.     

Book reviews

Islam: a challenge for Christianity (Concilium 1994/3). Hans Kung & Jurgen Moltmann (Eds), 1994. London, Concilium; Maryknoll, SCM Press; London, Orbis Books. 163 pp., pb. £8.95, ISBN 0–334–030269.

Cultures in Conflict: Christians, Muslims and Jews in the age of discovery. Bernard Lewis, 1995. New York, Oxford University Press. 101 pp., hb., $16.95, ISBN 0–19–509026–8.

Beyond Faith and Infidelity: the Sufi poetry and teachings of Mahmud Shabistari. L. Lewisohn, 1995. Richmond, Surrey, Curzon Press. 344 pp. pb. £14.99, 0–7007–0343–8.

The Prophet's Pulpit: Islamic preaching in contemporary Egypt. [Comparative Studies on Muslim Societies, 20]. Patrick Gaffney, 1994. Berkeley and Los Angeles, University of California Press. 367 pp., hb. £40.00, ISBN 0–520–08471–3, pb. £15.95, ISBN 0–520–08472–1.

Sufi and Scholar on the Desert Edge: Muhammad b. CA1i al‐Sanūsi and his Brotherhood. K. S. Vikor, 1995. London, Hurst & Co. 310 pp. hb. £37.50, ISBN 1 85065 218 X.

Children of Islam. Marie Parker‐Jenkins, 1995. Stoke‐on‐Trent, Trentham Books Ltd. 162 pp., £12.95, ISBN 1–85856 034 9.     

Methodological challenges in union commitment studies

Methodological problems in studies of union commitment were identified and illustrated with data from 4,641 members and 479 stewards in 297 local teachers' unions. Using a 20-item union commitment scale, results confirmed the existence of 3 substantive factors and 1 method factor at the individual level of analysis: loyalty to the union, responsibility to the union, willingness to work for the union, and a factor of negatively worded items. Tests of measurement invariance showed that the scale captured commitment for rank-and-file members but not for union stewards. The authors also found partial measurement invariance between long-time and newer members and full measurement invariance between men and women. Finally, the authors found that violation of the statistical assumption of independence reduced model fit when individual commitment scores were analyzed without attention to the hierarchical nature of the data.     

Exploring the Relationship between Psychopathy and Helping Behaviors in Naturalistic Settings: Preliminary Findings

This study examined the helping behavior of participants with high (High-P; 15 males, 13 females) and low (Low-P; 14 males, 16 females) psychopathic traits without their awareness. In the first of three tests, we found Low-P participants offered more help to an apparently lost female confederate than High-P participants. In the second test, High-P compared to Low-P males offered more help to an “injured” female experimenter, the reverse was true for females. In the third test, High-P compared to Low-P females offered more help to a female confederate who had apparently dropped papers they were carrying; whereas the reverse was true for males. Our preliminary findings indicate that context, gender and psychopathic traits interact and impact helping behavior.     

Creativity in Medical Education: The Value of Having Medical Students Make Stuff

What is the value of having medical students engage in creative production as part of their learning? Creating something new requires medical students to take risks and even to fail--something they tend to be neither accustomed to nor comfortable with doing. “Making stuff” can help students prepare for such failures in a controlled environment that doesn’t threaten their professional identities. Furthermore, doing so can facilitate students becoming resilient and creative problem-solvers who strive to find new ways to address vexing questions. Though creating something new can be fun, this is not the main outcome of interest. Rather, the principle reason we recommend devoting precious curricular time to creative endeavors is because it helps medical students become better doctors.