Aphasia type and aging in Hindi-speaking stroke patients

In this study, the clinical profile of Hindi-speaking stroke patients with aphasia from northern India has been investigated. We examined the interactional effect between age and gender with aphasia type in 97 Hindi-speaking right-handed individuals, the majority of them with a confirmed diagnosis of a cerebrovascular accident. The subjects included in the study ranged from 3 weeks to two years post-onset with a diagnosis of a common classical aphasia (Broca's, Wernicke's, anomic, global, conduction, and transcortical) types involving both males and females. Also examined was the interaction between literacy and aphasia type since the subjects had varied exposures to education (total illiteracy to professional/university education). While the data reported here about Hindi-speaking aphasics are relatively in agreement with the age-aphasia type patterns discussed in western countries, nonetheless some differences were also observed. The mean age of Indian patients with aphasia was significantly lower. Also, in addition to some gender and literacy related differences, an outstanding difference was that many clinical symptoms that are known to co-occur with aphasia were not readily reported by subjects with stroke.     

Neuroticism as mental noise: a relation between neuroticism and reaction time standard deviations

Those higher in neuroticism are often more variable in their behavior and experience. On the basis of this observation, the authors hypothesized that the trait of neuroticism might be correlated with the variability of performance pertaining to relatively basic cognitive operations. Three studies involving 242 college undergraduates supported this prediction in that neuroticism correlated positively with the variability of performance across trials of reaction time tasks. These results link neuroticism to cognitive noise that intervenes between stimulus and response. Such noise has been associated with executive dysfunctions (e.g., frontal lobe injury) in previous research. The present findings are potentially useful for understanding why neuroticism often correlates with variations in the functionality of cognition and behavior.     

Don't worry, be happy? Neuroticism, trait-consistent affect regulation, and performance

People regulate their affect either to feel good or to achieve instrumental success. The present experiments show that when driven by performance goals, people can be motivated to experience unpleasant affect when it is trait-consistent, because of its instrumental benefits (e.g., M. Tamir & M. D. Robinson, 2004). In 4 studies, individuals high in neuroticism were more likely than those low in neuroticism to choose to increase their level of worry, as indicated by self-reported preferences (Study 1) and by behavioral choices in experimental settings (Studies 2-4). As predicted, such preferences were evident when expecting to perform demanding tasks but not when expecting an undemanding task (Study 2). Study 4 suggests that such preferences for short-term unpleasant affect may be beneficial to performance.     

Changing views about personality disorders: Comment about the prospective studies CIC, CLPS, and MSAD

Three large-scale prospective studies (Children in the Community Study [CIC; Cohen, Crawford, Johnson, & Kasen, this issue], Collaborative Longitudinal Personality Disorders Study [CLPS; Skodol et al., this issue], and the McLean Study of Adult Development [MSAD; Zanarini, Frankenburg, Hennen, Reich, & Silk, this issue]) are discussed with respect to the following issues: shared and complementary features of the study designs, evidence for stable and changing personality disorder features, methodological issues (reliability, stability, and invariance), the relationship between Axis I and II disorders, and dimensional versus categorical representations of personality disorders.     

A facilitative role for corticosterone in the acquisition of a spatial task under moderate stress

Emotionally charged experiences alter memory storage via the activation of hormonal systems. Previously, we have shown that compared with rats trained for a massed spatial learning task in the water maze in warm water (25°C), animals that were trained in cold water (19°C) performed better and showed higher levels of the stress hormone corticosterone. Here, we examined whether manipulating the levels of corticosterone can determine the strength of spatial information acquisition and retention. Rats were injected with metyrapone (25, 50, and 75 mg/kg, i.p.) or with corticosterone (10 and 25 mg/kg, i.p.) and trained in a massed spatial task in either cold (19°C) or warm (25°C) water. We found that whereas animals injected with vehicle performed well in the spatial task in cold water (moderate stress), rats injected with the intermediate metyrapone dose showed impairment in performance. Moreover, whereas animals injected with vehicle on average did not perform well in warm water (mild stress), rats injected with the lower corticosterone dose showed improvement in performance in warm water. These two mirror experiments of corticosterone blockade and enhancement strongly suggest that corticosterone is instrumental in the acquisition and retention of the spatial learning task.     

The road not taken: creative solutions require avoidance of high-frequency responses

To investigate individual differences in creativity as measured with a complex problem-solving task, we developed a computational model of the remote associates test (RAT). For 50 years, the RAT has been used to measure creativity. Each RAT question presents three cue words that are linked by a fourth word, which is the correct answer. We hypothesized that individuals perform poorly on the RAT when they are biased to consider high-frequency candidate answers. To assess this hypothesis, we tested individuals with 48 RAT questions and required speeded responding to encourage guessing. Results supported our hypothesis. We generated a norm-based model of the RAT using a high-dimensional semantic space, and this model accurately identified correct answers. A frequency-biased model that included different levels of bias for high-frequency candidate answers explained variance for both correct and incorrect responses. Providing new insight into the nature of creativity, the model explains why some RAT questions are more difficult than others, and why some people perform better than others on the RAT.