Dissociative patterns of foreperiod effects in temporal discrimination and reaction time tasks

This study examined whether the process of temporal preparation for a target stimulus is the same regardless of the task required by the target stimulus. To this end, the same variable-foreperiod design was used in a temporal discrimination task (Experiment 1) and a reaction time task (Experiment 2). In Experiment 1, both temporal sensitivity and perceived duration increased as a function of foreperiod, whereas in Experiment 2, foreperiod did not influence reaction time. Furthermore, both temporal sensitivity and perceived duration revealed an asymmetric sequential effect of foreperiod, but the pattern of this effect was opposite to the pattern observed in the reaction time task. Together these dissociative patterns of foreperiod effects suggest that the mechanism of temporal preparation depends on the task required by the target stimulus.     

Context effects in auditory implicit memory

The context effect in implicit memory is the finding that presentation of words in meaningful context reduces or eliminates repetition priming compared to words presented in isolation. Virtually all of the research on the context effect has been conducted in the visual modality but preliminary results raise the question of whether context effects are less likely in auditory priming. Context effects in the auditory modality were systematically examined in five experiments using the auditory implicit tests of word-fragment and word-stem completion. The first three experiments revealed the classical context effect in auditory priming: Words heard in isolation produced substantial priming, whereas there was little priming for the words heard in meaningful passages. Experiments 4 and 5 revealed that a meaningful context is not required for the context effect to be obtained: Words presented in an unrelated audio stream produced less priming than words presented individually and no more priming than words presented in meaningful passages. Although context effects are often explained in terms of the transfer-appropriate processing (TAP) framework, the present results are better explained by Masson and MacLeod's (2000) reduced-individuation hypothesis.     

Repetition priming across distinct contexts: Effects of lexical status,word frequency,and retrieval test

Previous studies have shown an interference of task-irrelevant numerical information with the spatial parameters of visuomotor behaviour. These findings lend support to the notion that number and space share a common metric with respect to action. Here I argue that the demonstration of the structural similarity between scales for number and space would be a more stringent test for the shared metrics than a mere fact of interference. The present study investigated the scale of number mapping onto space in a manual estimation task. The physical size of target stimuli and the magnitudes of task-irrelevant numbers were parametrically manipulated in the context of the Titchener illusion. The results revealed different scaling schemas for number and space. Whereas estimates in response to changes in stimulus physical size showed a gradual increase, the effect of number was categorical with the largest number (9) showing greater manual estimate than the other numbers (1, 3, and 7). Possible interpretations that are not necessarily incompatible with the hypothesis of shared metrics with respect to action are proposed. However, the present findings suggest that a meticulous scale analysis is required in order to determine the nature of number–space interaction.     

Setting the stage subliminally: unconscious context effects

An important approach to understand how the brain gives rise to consciousness is to probe the depth of unconscious processing, thus to define the key features that cause conscious awareness. Here, we investigate the possibility for subliminal stimuli to shape the context for unconscious processing. Context effects have generally been assumed to require consciousness. In the present experiment, unconscious context processing was investigated by looking at the impact of the context on the response activation elicited by a subliminal prime. We compared the effects of the same subliminal prime on target processing when the prime was embedded in different unconscious contexts. Results showed that the same prime can evoke opposite responses depending on the unconscious context in which it is presented. Taken together, the results of this study show that context effects can be unconscious.     

Brief assessment of schizotypy: Developing short forms of the Wisconsin Schizotypy Scales

The Wisconsin Schizotypy Scales—the Perceptual Aberration, Magical Ideation, Physical Anhedonia, and Revised Social Anhedonia Scales—have been used extensively since their development in the 1970s and 1980s. Based on psychometric analyses using item response theory, the present work presents 15-item short forms of each scale. In addition to being briefer, the short forms omit items with high differential item functioning. Based on data from a sample of young adults (n = 1144), the short forms have strong internal consistency, and they mirror effects found for the longer scales. They thus appear to be a good option for researchers interested in the brief assessment of schizotypic traits. The items are listed in an Appendix A.     

Domain-specific assessment of anger expression and ambulatory blood pressure

Bongard and al’Absi (2003) proposed domain-specific anger expression as an improved method for measuring the expression of anger with stronger links to cardiovascular parameters. We tested this proposal by relating their domain-specific measure to ambulatory blood pressure. One hundred and forty-nine Singapore young adults responded to a modified version of the State-Trait Anger Expression Inventory that measured anger expression at home, school/work and leisure and then underwent 24 h ambulatory blood pressure monitoring. Results indicated significant differences in reported anger expression in the three domains measured and also showed that domain-specific measures of anger expression were more strongly related to ambulatory blood pressure than was the general measure of anger expression. These results provide additional evidence for the importance of measures of anger expression that take account of the specific context in which anger occurs.     

Conceptual implicit memory and environmental context

Changes in environmental context between encoding and retrieval often affect explicit memory but research on implicit memory is equivocal. One proposal is that conceptual but not perceptual priming is influenced by context manipulations. However, findings with conceptual priming may be compromised by explicit contamination. The present study examined the effects of environmental context on conceptual explicit (category-cued recall) and implicit memory (category production). Explicit recall was reduced by context change. The implicit test results depended on test awareness (assessed with a post-test questionnaire). Among test-unaware participants, priming was equivalent for same-context and different-context groups, whereas for the test-aware, the same-context group produced more priming. Thus, when explicit contamination is controlled, changes in environmental context do not impair conceptual priming. Context dependency appears to be a general difference between implicit and explicit memory rather than a difference between conceptual and perceptual implicit memory. Finally, measures of mood indicated no changes in affect across contexts, arguing against mood mediation for the context effects in explicit recall.     

Personality as a moderator of context effects on academic achievement

We investigated whether personality moderates group influence of classmates on academic achievement and whether these so-called context effects can be attributed to peer pressure. The sample consisted of 2498 students in their first year of Dutch secondary education. The data were analyzed by a two-level (students within classes) analysis, separately for boys (n = 1033, in 92 classes) and girls (n = 1465, in 119 classes). For both sexes, we found a context effect on Dutch language achievement but not on mathematics achievement. Emotional Stability appeared a moderator of this context effect but for girls only. The results suggest further that peer pressure is not a likely mechanism of group influence of classmates on academic achievement.     

Adverse developmental experiences and risky health behaviours among black South African university students

This study examined the relationship between adverse developmental experiences (ADEs) and risky health behaviours among a cross-sectional sample of black South African students (n = 393; females = 58%, M_age = 20.5 years, SD = 2.9). Binary logistic regression was used to model the association between categories of ADEs and risky health behaviours. Findings suggest individual ADEs to significantly predict risky health behaviours. The highest singular ADEs reported were being treated like a child (62%), parents being overprotective (59%), and being driven to be perfectionistic (58%). There was no indication of a general trend of ordered associations between the number of ADEs and risky health behaviours.     

The Effect of Anxiety on the Cognitive Functioning in Non-clinical Schizotypal Individuals

Schizotypal personality disorder (SPD) is characterized by eccentric behavior and perceptual distortions that closely resemble the patterns observed in those with schizophrenia. Schizophrenia and related personality disorders (i.e., SPD) are associated with deficits in sustained attention, slower than normal reaction times, and manifestations of working memory deficits and erratic cognitive tasks. The present study used the schizotypal personality scale (STA) to compare cognitive abilities of self-reported low schizotypic tendency subjects with high schizotypic tendency subjects. The group scores on the STA differed significantly. Those with high STA scores also tended to have higher state and trait anxiety scores based on the State-Trait Anxiety Inventory (STAI). The groups did not significantly differ on any of the demographic variables tested, including age, education, self-rated health status, and medication. Along with an executive function test, two computerized tasks tested subjects on reaction time and memory. Even when covariates (i.e., state, trait anxiety scores) were analyzed, there were no significant differences between the groups and tasks, although the gathered data showed trends in the expected direction.     

The Effect of Anxiety on the Cognitive Functioning in Non-clinical Schizotypal Individuals

Schizotypal personality disorder (SPD) is characterized by eccentric behavior and perceptual distortions that closely resemble the patterns observed in those with schizophrenia. Schizophrenia and related personality disorders (i.e., SPD) are associated with deficits in sustained attention, slower than normal reaction times, and manifestations of working memory deficits and erratic cognitive tasks. The present study used the schizotypal personality scale (STA) to compare cognitive abilities of self-reported low schizotypic tendency subjects with high schizotypic tendency subjects. The group scores on the STA differed significantly. Those with high STA scores also tended to have higher state and trait anxiety scores based on the State-Trait Anxiety Inventory (STAI). The groups did not significantly differ on any of the demographic variables tested, including age, education, self-rated health status, and medication. Along with an executive function test, two computerized tasks tested subjects on reaction time and memory. Even when covariates (i.e., state, trait anxiety scores) were analyzed, there were no significant differences between the groups and tasks, although the gathered data showed trends in the expected direction.     

Preschoolers' use of surface similarity in object comparisons: taking context into account

Previous research has emphasized the role of within-match similarity in children's comparisons. The current study investigated another potentially important contributing factor, namely the distinctiveness of the matching items relative to other items in the scene. Using a well-known relational mapping task, we found that 3- and 4-year-olds made more correct matches between identical objects when those objects were maximally distinctive from the foils. In a cross-mapping experiment, where same relative size was pitted against object similarity, 3-year-olds made more incorrect object matches when the objects were both similar to each other and distinctive from the foils. Furthermore, 3- and 4-year-olds performed the same, regardless of within-match similarity, so long as the ratios of within-match and nonmatch similarity were roughly equal. These findings suggest that children's comparisons are guided by a ratio consisting of many pairwise similarity relations, including (but not limited to) the degree of within-match similarity.