Measuring socioeconomic status: reliability and preliminary validity for different approaches

This study investigated issues related to commonly used socioeconomic status (SES) measures in 140 participants from three cities (Atlanta, Boston, and Toronto) in two countries (United States and Canada). Measures of SES were two from the United States (four-factor Hollingshead scale, Nakao and Treas scale) and one from Canada (Blishen, Carroll, and Moore scale). Reliability was examined both within (interrater agreement) and across (intermeasure agreement) measures. Interrater reliability and classification agreement was high for the total sample (ranger = .86 to .91), as were intermeasure correlations and classification agreement (range r = .81 to .88). The weakest agreement across measures was found when families had one wage earner who was female. Validity data for these SES measures with academic and intellectual measures also were obtained. Some support for a simplified approach to measuring SES was found. Implications of these findings for the use of SES in social and behavioral science research are discussed.     

The effect of similarity between elemental stimuli and compounds in olfactory patterning discriminations

We studied the ability of honeybees to discriminate between single odorants and binary olfactory mixtures. We analyzed the effect of the number of common elements between these two stimulus classes on olfactory discrimination. We used olfactory conditioning of the honeybees' proboscis extension reflex (PER), a paradigm in which odors can be associated with a reinforcement of sucrose solution. Bees were asked to discriminate reinforced from nonreinforced olfactory stimuli. They were trained with two elemental odors (A and B) versus a binary olfactory mixture. The mixture was either AB (group 2CE, two common elements), AC (group 1CE, one common element A), or CD (group 0CE, no common element). Three groups followed a positive patterning schedule (mixture reinforced and elements nonreinforced: groups 2CE+, 1CE+, and 0CE+) and three other groups a negative patterning schedule (mixture nonreinforced and elements reinforced: groups 2CE-, 1CE-, and 0CE-). We showed that a reduction of similarity (number of common elements) between elemental odors and compounds enhanced the ability to discriminate elements from compounds and that the kind of compound processing used by the bees supports theories that assume nonelemental compound processing (i.e., that exclude the mere summation of the elemental associative strengths upon compound presentation).     

Windowed cross-correlation and peak picking for the analysis of variability in the association between behavioral time series

Cross-correlation and most other longitudinal analyses assume that the association between 2 variables is stationary. Thus, a sample of occasions of measurement is expected to be representative of the association between variables regardless of the time of onset or number of occasions in the sample. The authors propose a method to analyze the association between 2 variables when the assumption of stationarity may not be warranted. The method results in estimates of both the strength of peak association and the time lag when the peak association occurred for a range of starting values of elapsed time from the beginning of an experiment.     

Rats use a sense of direction to alternate on T-mazes located in adjacent rooms

Lister hooded rats were trained on a forced-sample T-maze alternation task in an environment lacking spatial landmarks. An early study of spontaneous alternation on the T-maze had shown that rats use a "spatial sense" to select alternate maze arms across mazes. As this phenomenon may provide a useful tool for studying the neural substrates of a directional sense, we wished to confirm this finding on a different version of the T-maze task, with well-trained animals. We found that rats successfully selected the appropriate maze arm when the choice phase of the task was presented on a second maze, oriented in the same direction, and located in an adjacent room. However, choice performance fell to chance level when the second maze was oriented 90° relative to the first. This result suggests that the rats do not simply alternate turns across the two environments, but rather that they rely on a sense of direction that is carried across environments. Electronic Publication     

Understanding the latent structure of job performance ratings

This study quantified the effects of 5 factors postulated to influence performance ratings: the ratee's general level of performance, the ratee's performance on a specific dimension, the rater's idiosyncratic rating tendencies, the rater's organizational perspective, and random measurement error. Two large data sets, consisting of managers (n = 2,350 and n = 2,142) who received developmental ratings on 3 performance dimensions from 7 raters (2 bosses, 2 peers, 2 subordinates, and self) were used. Results indicated that idiosyncratic rater effects (62% and 53%) accounted for over half of the rating variance in both data sets. The combined effects of general and dimensional ratee performance (21% and 25%) were less than half the size of the idiosyncratic rater effects. Small perspective-related effects were found in boss and subordinate ratings but not in peer ratings. Average random error effects in the 2 data sets were 11% and 18%.     

Use of photic feedback as an adjunct treatment in a case of Miller Fisher syndrome

Photic Feedback treatment of a patient diagnosed with Miller Fisher syndrome has resulted in the rapid and permanent remission of symptoms. During Photic Feedback treatment, the CD20 appeared to be slightly increased. This may have been associated with changes in humoral immunity. The present clinical observation of a single patient suggests that Photic Feedback treatment should be investigated as a possible adjunct therapy for patients who suffer from polyneuropathies, such as Miller Fisher syndrome, within a carefully controlled clinical trial.     

Temporal characteristics of line orientation identification

The hypothesis that identification of line orientation is based on different mechanisms--a detector mechanism at large orientation differences and a computational one at small orientation differences--was tested in three experiments. The first two experiments compared reaction time and time of complete temporal summation (tc) in two tasks, line detection and line orientation identification. Identification at orientation differences 15 degrees or more was similar to detection in several respects, suggesting that it was accomplished according to the principle of "labeled lines." In agreement with the initial hypothesis, identification at differences smaller than 15 degrees had a slower time course and could not be explained by the "labeled lines" principle. Experiment 3 explored the orientation acuity as a function of exposure duration and stimulus energy. Energy could not completely substitute for time in providing high orientation acuity, a result suggesting the involvement of neurophysiological mechanisms of large time constants.     

Object-based selection operates on a grouped array of locations

In two experiments, space- and object-based selection effects were investigated, using variants of the ring-cuing paradigm of Egly and Homa (1984). The results revealed significant cuing modulation for nonring configurations of target locations spanning a range of retinal eccentricities, with the cuing effects independent of eccentricity and confined to the configuration of locations (rather than extending to locations within the space enclosed by the cued configuration). These results are consistent with object-based selection operating on a grouped spatial array (Vecera & Farah, 1994). Object selection may be based on a supradimensional saliency map representation of the field, modulated by feature-specific segmentation mechanisms (e.g., an object may be made salient on the basis of its color). Complex objects may be represented by grouped saliency signals. In this way, a two-dimensional spatial (saliency) representation may provide the common format for object-based selection, prior to full object definition.