Distractor clustering enhances detection speed and accuracy during selective listening

The effects of distractor clustering on target detection were examined in two experiments in which subjects attended to binaural tone bursts of one frequency while ignoring distracting tones of two competing frequencies. The subjects pressed a button in response to occasional target tones of longer duration (Experiment 1) or increased loudness (Experiment 2). In evenly spaced conditions, attended and distractor frequencies differed by 6 and 12 semitones, respectively (e.g., 2096-Hz targets vs. 1482- and 1048-Hz distractors). In clustered conditions, distractor frequencies were grouped; attended tones differed from the distractors by 6 and 7 semitones, respectively (e.g., 2096-Hz targets vs. 1482- and 1400-Hz distractors). The tones were presented in randomized sequences at fixed or random stimulus onset asynchronies (SOAs). In both experiments, clustering of the unattended frequencies improved the detectability of targets and speeded target reaction times, Similar effects were found at fixed and variable SO As. Results from the analysis of stimulus sequence suggest that clustering improved performance primarily by reducing the interference caused by distractors that immediately preceded the target.     

Procedural fairness and self-esteem

We argue that people's self-esteem is affected by the fairness of procedures to which they are subjected; unfair treatment will lower self-esteem. Moreover, since this influence on self-esteem is presumably due to the implicit evaluation expressed by the choice of procedure and hence by the evaluation expressed by the person implementing the procedure, people's concern with the fairness of treatment will be focused on the interactional aspects of the procedure. In two experiments designed to test these hypotheses subjects received either a high or a low grade on an ability test on the basis of either fair or unfair grading procedures. The results of Experiment 1 indicated that subjects' self-esteem was lower after unfair treatment, and this influence was only apparent when subjects received high test feedback. Additionally, ratings of the fairness of the interaction were lower following unfair grading procedures. Experiment 2 also manipulated level of involvement with the test. Self-esteem was affected by procedural fairness and procedural fairness influenced perceived fairness of the interaction only in the high involvement condition.     

Additive latency effects of selective and nonselective restricted priming types

The purpose of this investigation was to examine further the contention of Alain et al. (1988) that a third priming type exists, called nonselective restricted (NSR) and controlled by response probability, which is distinct from those types influenced by foreperiod duration (nonselective general priming) and prediction probability (selective priming). In a four-choice reaction time (RT) task, prediction probability (.5, .7, & .9, indicating the likelihood of a particular response) and response probability (.5, .9, denoting the likelihood that a response would be needed at all) exerted significant but noninteractive effects on RTs for prepared responses (most probable), suggesting that each of these probabilities influence different priming types (Sternberg, 1969; selective and NSR, respectively). This was further indicated by the fact that prediction probability, but not response probability, significantly altered RTs for the unprepared (lesser probable) responses. Finally, the hypothesized nonselective character of NSR priming (i.e., all outputs controlled by response probability are equally affected by its value changes) was supported when responses were equiprobable, and, while the null effect of response probability just mentioned seemingly argued against this property when selective priming took place, the interpretation provided herein negated this opposition.     

Racial bias and the MCMI

We studied the scores obtained on the Millon Clinical Multiaxial Inventory (MCMI) by Black and White male psychiatric inpatients to determine the presence or absence of racial bias. In predicting psychopathology for the two races, comparisons of MCMI performance indicated significant differences for all diagnoses except the personality disorders. The subjects were then matched into two groups of 209 patients each, according to DSM-III psychiatric diagnoses. The data were analyzed at the item, scale, and structural levels. At the item level, application of the Mantel-Haenszel Procedure revealed that 45 of the 175 items of the inventory were answered significantly different by the two racial groups. Because this number was higher than what could be expected by chance, the finding suggested possible deficiencies in terms of the culture-fairness of the items used in the test. At the scale level, an analysis of variance (ANOVA) demonstrated that the scores obtained by the Black and White groups were significantly different in 9 of the 20 scales (Histrionic, Narcissistic, Antisocial, Paraphrenia, Hypomania, Dysthymia, Alcohol Abuse, Drug Abuse, and Psychotic Delusion). With the exception of the Dysthymic scale, all of the differences were in the direction of the Blacks obtaining a higher score than the Whites. At the structural level, however, a principal components factor analysis performed on each group resulted in factor structures that looked identical.     

An on-line assessment of causal reasoning during comprehension

Fletcher and Bloom (1988) have argued that as readers read narratives, clause by clause, they repeatedly focus their attention on the last preceding clause that contains antecedents but no consequences in the text. This strategy allows them to discover a causal path linking the text's opening to its final outcome while minimizing the number of times long-term memory must be searched for missing antecedents or consequences. In order to test this hypothesis, we examined the reading times of 25 subjects for each clause of eight simple narrative texts. The results show that: (1) causal links between clauses that co-occur in short-term memory (as predicted by the strategy) increase the time required to read the second clause; (2) potential causal links between clauses that never co-occur in short-term memory (again as predicted by the strategy) have no effect on reading time; and (3) reinstatement searches are initiated at the end of sentences that are causally unrelated to the contents of short-term memory or that contain clauses that satisfy goals no longer in short-term memory. These results support the claim that subjects engage in a form of causal reasoning when they read simple narrative texts.     

Updating an object’s orientation and location during nonvisual navigation: A comparison between two processing modes

In the present study, we compared the effects of two processing modes on the updating of the location and orientation of a previously viewed object in space during a guided walk without vision. In Experiment 1, in order to measure the error for initial perception of object’s orientation, 12 subjects rotated a miniature model until it matched the memorized orientation of its counterpart object in space. In Experiment 2, they attempted either to keep track of the object continuously (in the object-centered [OC] task) or to estimate the object’s perspective only at the terminal vantage point given the trajectory they walked (in the trajectory-centered [TC] task). Subjects indicated the location of the object by facing it, and then rotated the model in order to indicate its orientation from the new vantage point. Results showed that, with respect to the TC mode, the OC mode induced a slowdown of the subjects’ self-paced locomotion velocity for both linear and angular movements, and a decrease of the latencies as well as smaller absolute errors for the orientation-of-the-object response. Mean signed errors on object’s orientation were equivalent for both processing modes, suggesting that the latter induced different allocations of processing resources on a common representation of space updated by “path integration.”     

Separability of item and person parameters in response time models

This paper discusses two forms of separability of item and person parameters in the context of response time (RT) models. The first is separate sufficiency: the existence of sufficient statistics for the item (person) parameters that do not depend on the person (item) parameters. The second is ranking independence: the likelihood of the item (person) ranking with respect to RTs does not depend on the person (item) parameters. For each form a theorem stating sufficient conditions, is proved. The two forms of separability are shown to include several (special cases of) models from psychometric and biometric literature. Ranking independence imposes no restrictions on the general distribution form, but on its parametrization. An estimation procedure based upon ranks and pseudolikelihood theory is discussed, as well as the relation of ranking independence to the concept of double monotonicity.I am indebted to Wim van der Linden for bringing Thissen's (1983) paper to my notice, and to Martijn Berger, Frans Tan, and the anonymous reviewers for their constructive comments on earlier drafts of this paper.