Positional discriminability in linear orderings

Subjects were taught two eight-term linear orders of the form “A taller than B taller than C ….,” They were then asked to choose the “taller” term in all possible pairwise combinations within each series, and reaction time was measured for each pair. In addition, subjects performed a further task in which they judged whether or not two terms were adjacent in the ordering. In subsequent sessions, subjects were told that the “shortest” term on one list was taller than the “tallest” term on the other, so that the two lists were merged into a single 16-term series. They were then required to choose the “taller” term for both within-groups and between-groups pairs. Subjects did not appear to use the initial groupings in performing this task, even when given training on differential categorical codes (“tall” vs. “short”) for the two sublists. Rather, subjects in all tasks appeared to represent the items as ordered positions along an internal array, so that comparison times depended largely on the differential discriminability of the item positions. In each task decisions were made more quickly if the terms being compared were near the ends of the ordering, rather than near the middle.     

The role of imagery in the representation of linear orderings

Two experiments were carried out to investigate whether visual imagery was used in representing transitive linear ordering relationships. Subjects were presented with passages describing either a linear ordering or a set inclusion relationship, while being subjected to either visual or verbal interference. Performance was tested by asking subjects to judge the truth or falsity of statements concerning both the information presented in the passages and inferences that could be drawn from this information. In neither experiment was there any evidence for the linear ordering material being selectively disrupted by the visual interference task, as would have been predicted by the imagery theory. Thus it is concluded that linear orderings are probably not represented as visual images.     

The role of memory in the construction of linear orderings

Two experiments examined the construction of linear orderings (e.g., ABCD) from presented pairs of adjacent items (e.g., AB, BC, CD) in an attempt to determine why some orders of presentation are more difficult than others. Experiment 1 found order effects when participants constructed orderings but not when they simply recalled presented pairs, suggesting that order effects reflect processing difficulties encountered during construction. Experiment 2 used several different orders and successive and simultaneous visual presentation of pairs. Results showed that order effects can be attributed to the memory load imposed by certain pairs, the type of processing demanded, the need to reorder previously stored information, and the loss of information with continued rehearsal. Results strongly support the Foos, Smith, Sabol, and Mynatt (1976) model of linear construction.     

Speech abnormalities in seizures: a comparison of absence and partial complex seizures

In order to determine whether speech changes are useful in differentiating seizure types, a study was done in which speech abnormalities during two distinct seizure types, partial complex and absence seizures, were compared. Speech changes noted during prolonged electroencephalographic and video monitoring were compared in 16 patients with 47 partial complex seizures and 19 patients with 95 absence seizures. Speech changes were common during both seizure types. Although some significant differences in speech patterns were noted in the two seizure types, the degree of overlap was such to preclude using speech changes alone as the sole clinical criteria in differentiating the seizures.     

Single linear ordering versus multiple discrepant orderings in the cognitive representation of social structures

Previous studies have assumed that people have a predilection for single linear orderings, of which status congruence is a special case. Eighty-two subjects were run in a two-stage experiment to examine preference for linear orderings and whether single or multiple discrepant orderings are preferred when 1 instead of having to learn, subjects freely construct social structures, and 2 the material they are presented is more specified and less simplified than is usually the case in cognitive bias studies. In the first stage Ss were presented with sets of five individual characteristic dimensions, of which three were inherently orderable. Their task was to attribute one characteristic from each dimension to each of five fictitious persons. In the second stage, Ss were asked, for three types of influence (professional, political and cultural), to build an influence structure among the five persons constructed in the first stage. In Stage 1, linear ordering was used for three of the five dimensions. Two of these dimensions used a single ordering, while the third was only weakly related to the first two. In Stage 2, largely transitive but incomplete relations of influence were established, based on a salary-occupational hierarchy. The completeness of the relation depended on the nature of the influence.     

Repeated challenge studies: A comparison of union-intersection testing with linear modeling

Challenge studies are often implemented for assessing whether a subject is sensitive to a certain agent or allergen. In particular, researchers test groups of subjects to determine if there really exists a causal relationship between some agent of interest and a response. To answer such a question, we need to detect the presence of the phenomenon in just one individual. Typically, however, there are a large number of unknown risk factors associated with the response and a potentially small population prevalence. Hence, standard statistical techniques, by averaging the treatment effect across the group, may miss a significant response of a single individual and lead to inconclusive results. We develop an alternative approach based on union-intersection testing that will allow a practitioner to correctly examine observations on an individual apart from the other subjects and test the hypothesis of interest: Does the phenomenon exist in the population? More specifically, we show how this technique adjusts for the multiple number of tests encountered when analyzing data for each individual subject separately. Furthermore, we demonstrate power calculations for the determination of sample size prior to performing the study. The performance of the union-intersection approach in comparison to linear models and semiparametric techniques is considered through sample size calculations and simulations. The union-intersection testing methodology out performs the Kolmogorov tests. However, the nested linear model performs as well if not better than the union-intersection tests. To illustrate the ideas presented in the paper, we provide an application in which we analyze psychological data collected by way of a challenge study design.     

A comparison of panel designs with routing methods in the multistage test with the partial credit model

In this study, we compared panel designs applied with various routing methods in the multistage test (MST) based on the partial credit model in the context of classification testing. Simulations were performed to compare three routing methods and four panel structures. Conditions of two test lengths and three passing rates were also included. The results showed that, regardless of the routing method used, the same panel structure performed similarly in terms of the precision of the classification decision with the same test length condition. The longer test length produced higher accuracy, whereas the 50 % passing rate yielded the lowest accuracy. Finally, all MST conditions performed well in terms of test security.     

Effectiveness of bright light therapy in cyclothymic axis syndromes--a cross-over study in comparison with partial sleep deprivation

In a preliminary crossover study, fifty patients with a cyclothymic axial syndrome were given bright-light treatment, while fifty other such patients were treated by means of partial sleep deprivation, 60% of the patients responded to bright-light treatment, as opposed to 50% of the patients partially deprived of sleep. The superior results of the bright-light treatment (Hamilton Depression Scale) are confirmed on the Nurses' Observation Scale for Inpatient Evaluation and the Profile of Mood States. Comparatively young patients with a not so extremely marked depression show the best response rates. Bright-light treatment is also effective against depressive disorders in non-seasonal depressions.     

Oral cavity awareness in nonnative speakers acquiring English

This investigation assessed awareness of the oral cavity of nonnative speakers acquiring English. University students (60 men, 60 women) were placed into three equal-size groups. The Less Experienced group lived in the USA less than 6 mo. (M = 3.3 mo., SD = 2.4). The More Experienced group lived in the United States 3 or more years (M = 5.0 yr., SD = 1.9). Native English speakers were the control group. Participants were recruited from undergraduate general education classes and passed a speech screening in English including accurate production of the seven English syllables tested, namely, suh, luh, tuh, kuh, ruh, shuh, and thuh. Participants answered four multiple-choice questions about lingual contact for each of the syllables imitated. Total test mean scores were significantly higher for the More Experienced group. Native speakers performed the task best. Findings support the effects of amount of time speaking the language. Training methods employed to teach English and slight dialectal variations may account for the significant differences seen in the two groups of nonnative speakers. Further study is warranted.     

Resistance to continuous delay of reinforcement or extinction following partial delay or partial reinforcement in acquisition: A direct comparison

Rats received either partial reward (PR) or partial delay (PD) in acquisition with one, two, or three delay or nonreward trials followed by an immediately rewarded trial or one delay or nonreward trial followed by an immediately rewarded trial. These four groups were then split in half and given either continuous delay or continuous nonreward (extinction) in a “response persistence” phase. In addition, two continuously reinforced groups, one experiencing continuous delay, and the other experiencing extinction were included. The results showed that response persistence was greater when PD groups were given continuous delay rather than extinction, but the opposite was true for PR groups. The “length” (1, 2, or 3 versus 1 nonreward or delay trial) also transferred to the response persistence phase with the length 1, 2, and 3 conditions being more persistent than the 1 length conditions. The results were discussed with respect to theoretical notions of response persistence.     

Complex partial epileptic-like experiences in university students and practitioners of Dharmakaya in Thailand: comparison with Canadian university students.

We tested the hypothesis that individuals who frequently practice meditation within another culture whose assumptions explicitly endorse this practice should exhibit more frequent and varied experience associated with complex partial epilepsy (without the seizures) as inferred by the Personal Philosophy Inventory and Roberts' Questionnaire for the Epileptic Spectrum Disorder. 80 practitioners of Dharma Meditation and 24 university students in Thailand were compared with 76 students from first-year courses in psychology in a Canadian university. Although there were large significant differences for some items and clusters of items expected as a result of cultural differences, there were no statistically significant differences between the two populations for the proportions of complex partial epileptic-like experiences or their frequency of occurrence. There were no strong or consistent correlations between the history of meditation within the sample who practiced Dharma meditation and these experiences. These results suggest complex partial epileptic-like experiences may be a normal feature of the human species.     

The role of language in acquiring object kind concepts in infancy

Four experiments investigated whether 9-month-old infants could use the presence of labels to help them establish a representation of two distinct objects in a complex object individuation task. We found that the presence of two distinct labels facilitated object individuation, but the presence of one label for both objects, two distinct tones, two distinct sounds, or two distinct emotional expressions did not. These findings suggest that language may play an important role in the acquisition of sortal/object kind concepts in infancy: words may serve as "essence placeholders". Implications for the relationship between language and conceptual development are discussed.     

A comparison of cue competition in a simple and a complex design

Recent evidence suggests that controlled reasoning processes play an important role in cue competition in human causal learning (see De Houwer, J., Beckers, T., & Vandorpe, S. (2005). Evidence for the role of higher-order reasoning processes in cue competition and other learning phenomena. Learning &Behavior, 33(2), 239-249, for a review). Until now, this evidence comes almost exclusively from studies with simple designs that involved only a limited number of cues. Little is known about the role of controlled reasoning processes when the design is more complex. It is important to examine this issue because the complexity of the design could determine the resources that are available for reasoning and thus the role that reasoning plays in cue competition. We directly compared cue competition in a simple and a complex design. The results showed that complexity of the design affected retrospective cue competition but not forward cue competition. More fine grained analyses with respect to retrospective cue competition showed that unovershadowing but not backward blocking differed significantly between complexity conditions.     

A comparison of linear and mixture models for discriminant analysis under nonnormality

Methods for discriminant analysis were compared with respect to classification accuracy under nonnormality through Monte Carlo simulation. The methods compared were linear discriminant analyses based both on raw scores and on ranks; linear logistic discrimination; and mixture discriminant analysis. Linear discriminant analysis and linear logistic discrimination were suboptimal in a number of scenarios with skewed predictors. Linear discriminant analysis based on ranks yielded the highest rates of classification accuracy in only a limited number of situations and did not produce a practically important advantage over competing methods. Mixture discriminant analysis, with a relatively small number of components in each group, attained relatively high rates of classification accuracy and was most useful for conditions in which skewed predictors had relatively small values of kurtosis.     

Deficits in acquiring language structure: The importance of using prosodic cues

The study investigates and supports the hypothesis that (1) specifically language-impaired (SLI) children have deficits in processing and using the rhythmic-prosodic structure of speech; and that (2) these deficits impede the implicit learning of formal regularities of input language. The ability of SLI children to exploit prosodic cues in rule learning was tested in an experimental design using a miniature language. Twenty-four SLI children (mean age 6;5) learned a small set of sentences generated by a content-free rule system. The sample sentences were presented either with or without prosodic cues to the underlying formal regularities. The experimental groups were matched by various cognitive and language indicators. To assess whether they had acquired some regularities of the miniature language, a grammaticality judgement task was presented. In addition, their ability to reproduce rule-structured and rule-violating strings was tested. The experimental as well as some additional correlational data support the basic theoretical assumptions. The children had deficits in processing and exploiting prosodic cues in rule learning, and these deficits covaried with their rhythmic ability as indicated by a rhythm discrimination task.