Typicality effects in artificial categories: is there a hemisphere difference?

In category classification tasks, typicality effects are usually found: accuracy and reaction time depend upon distance from a prototype. In this study, subjects learned either verbal or nonverbal dot pattern categories, followed by a lateralized classification task. Comparable typicality effects were found in both reaction time and accuracy across visual fields for both verbal and nonverbal categories. Both hemispheres appeared to use a similarity-to-prototype matching strategy in classification. This indicates that merely having a verbal label does not differentiate classification in the two hemispheres.     

Worker and caller variety in three crisis centers.

Worker and caller behaviors are studied and compared in an available sample of 100 suicidal calls to three crisis intervention centers. Caller-Worker Interaction Program results were compared among the three centers. Worker and caller differences across centers were significant in 32 of 41 categories (p less than .05); using four discriminant functions, 2 of 18 hit percentages exceeded p less than .01. The verbal behaviors of workers and callers at the three centers are substantially different, leading to the conclusion that crisis intervention is dissimilarly practiced between centers but similar within them.     

Age-related differences in movement strategies and postural control during stooping and crouching tasks

While epidemiologic data suggests that one in four older adults have difficulty performing stooping and crouching (SC) tasks, little is known about how aging affects SC performance. This study investigated differences between young and older adults in lower limb kinematics and underfoot center of pressure (COP) measures when performing a series of SC tasks. Twelve healthy younger and twelve healthy older participants performed object-retrieval tasks varying in: (1) initial lift height, (2) precision demand, and (3) duration. Whole-body center of mass (COM), underfoot COP, and hip and knee angular kinematics (maximum angles and velocities) were analyzed. Compared to younger, older participants moved slower when transitioning into and out of pick-up postures that were characterized by less hip and knee flexion. Older participants also showed a diminished ability to adapt to the changing postural demands of each set of tasks. This was especially evident during longer tasks, whereby older individuals avoided high knee flexion crouching postures that were commonly used by younger participants. Older adults also tended to exhibit faster and more frequent COP trajectory adjustments in the anterior–posterior direction. It is likely that limitations in physical characteristics such as lower limb strength and range of motion contributed to these differences.     

Work environment and health in different types of temporary jobs

The aim of the study was to compare and analyse differences in work conditions and health between workers in permanent and temporary employment. The study group consisted of a representative, stratified sample of the Swedish working population (n = 2767). The data support the main hypothesis of the study, i.e., that temporary employed differ from permanent employed in control over their working life. With some exceptions, there were clear differences between these two categories with respect to a number of variables that can be regarded as central to both the individual's success at work and protection against job loss and exclusion from working life. Health differences were in favour of the permanent employed. There were also considerable differences between different sub-groups of temporary employees of such amplitude and consistency that they formed a distinct centre-periphery structure.     

Using a classification of occupations to describe age,sex, and time differences in employment patterns

Employment data from the 1960 and 1970 censuses were organized using Holland's occupational classification to examine age, sex, and level differences in employment, and to detect changes over the 10-year period. Data were organized in terms of both kind and level of work. Arranging information about the occupational structure of the workforce in terms of a classification that parallels the way psychologists describe people facilitates some psychological interpretations of employment patterns. For example, realistic work is becoming relatively less common and the sexual composition of the occupational categories may be changing. The results provide structured information about the workforce and its changing nature that can be communicated to people planning their careers, personnel workers and counselors, and to government agencies and planners.     

THE DIRECT AND GENERALIZED EFFECTS OF SELF INSTRUCTIONS AND PICTURE PROMPTS ON VOCATIONAL TASK PERFORMANCE

We evaluated the effects of self instructions and picture prompts on vocational task performance of three workers with mild to moderate mental retardation. The workers were asked to perform a packaging task that changed daily. Picture prompts were always present. In the verbal training phase, workers learned self instructions regarding the use of picture prompts to cue their performance on the packaging task. In the verbal and task training phase, workers learned to use the self instructions and picture prompts together to guide their task performance. The results showed that verbal training was sufficient for one worker, but that the other two workers required the combined verbal and task training to improve their task performance. For all subjects, there was evidence of generalization of the self management strategies and task performance and maintenance of both over time.     

Sex differences in verbal fluency: the role of strategies and instructions

Sex differences in verbal fluency performance and strategies are highly controversial, nevertheless suggesting a slight female advantage at least for phonemic fluency. A tendency of increased clustering of words into phonemic and semantic subcategories in men and increased switching between those categories in women has been suggested. In spatial tasks, it has been demonstrated that changes in instructions favoring a certain cognitive strategy can alter sex differences in performance. Such an approach has, however, not been attempted previously with verbal tasks. In the present investigation, 19 women in their luteal cycle phase and 23 men performed a phonemic and a semantic fluency task with three different instructions, one neutral, one emphasizing the clustering, and one emphasizing the switching of words. While under neutral instructions no sex differences were observed in verbal fluency performance and strategies, sex differences in switching and overall performance were observed in semantic fluency with an instruction requiring a switching strategy. Furthermore, correlation analyses suggested that the importance of strategies for overall performance differed between women and men. While only switching, but not clustering was related to overall verbal fluency performance in all tasks under all instructions, this relationship was driven by women in the phonemic task, but by men in the semantic task. These results highlight the importance of a consistent methodology in sex difference research. Slight variations in instructions may in part explain inconsistencies regarding sex differences in verbal fluency between previous studies.     

首次咨询中心理咨询师的言语反应类型

本研究旨在探索心理咨询师在首次咨询中言语反应类型。研究选择4位在高校从事心理咨询的咨询师作为研究对象,对首次咨询录像进行文本分析。结果：咨询师在首次咨询中的言语反应类型按反应功能和效果分为设置性反应、倾听性反应、跟进性反应和影响性反应;4种反应类型共由25种子类别组成;不同咨询师在首次咨询中均使用了4种反应类型。结论：持续使用倾听性反应有利于后续咨询的维持;影响性反应的过度使用导致首次咨询后来访者易脱落。     

Lateralization of spatial categories: A comparison of verbal and visuospatial categorical relations

Many reports show that spatial relations between and within objects show differences in hemispheric lateralization. Coordinate, metric relations concerning distances are processed with a right-hemisphere advantage, whereas a left-hemisphere advantage is thought to be related to categorical, abstract relations (Kosslyn, 1987). Kemmerer and Tranel (2000) argued that the left-hemisphere advantage for categorical processing might apply only for verbal spatial categories, however, whereas a right-hemisphere advantage is related to visuospatial categories. To test this idea, we examined categorical processing for stimuli in both verbal and visuospatial formats, with a visual half-field, match-to-sample design. In Experiment 1, we manipulated the format of the second stimulus to compare response patterns for both verbal and visuospatial stimuli. In Experiment 2, we varied the expectancy of the format of the second stimulus, allowing for an assessment of strategy use. The results showed that a left-hemisphere advantage was related to verbal stimulus format only, but not in all conditions. A right-hemisphere advantage was found only with a visuospatial expectancy, visuospatial format, and brief interval. The theory we present to explain these results proposes that the lateralization related to basic categorical processing can be strongly influenced by verbal characteristics and, to some extent, by additional coordinate processing. The lateralization measured in such cases does not represent lateralization related purely to categorical processing, but to these additional effects as well. This stresses the importance of careful task and stimulus design when examining categorical processing in order to reduce the influence of those additional processes.     

Impact of lumbar spine posture on thoracic spine motion and muscle activation patterns

Complex motion during standing is typical in daily living and requires movement of both the thoracic and lumbar spine; however, the effects of lumbar spine posture on thoracic spine motion patterns remain unclear. Thirteen males moved to six positions involving different lumbar (neutral and flexed) and thoracic (flexed and twisted) posture combinations. The thoracic spine was partitioned into three segments and the range of motion from each posture was calculated. Electromyographical data were collected from eight muscles bilaterally. Results showed that with a flexed lumbar spine, the lower-thoracic region had 14.83° and 15.61° more flexion than the upper- and mid-thoracic regions, respectively. A flexed lumbar spine significantly reduced the mid-thoracic axial twist angle by 5.21° compared to maximum twist in the mid-thoracic region. Functional differences emerged across muscles, as low back musculature was greatest in maintaining flexed lumbar postures, while thoracic erector spinae and abdominals showed bilateral differences with greater activations to the ipsilateral side. Combined postures have been previously identified as potential injury modulators and bilateral muscle patterns can have an effect on loading pathways. Overall, changes in thoracic motion were modified by lumbar spine posture, highlighting the importance of considering a multi-segmented approach when analyzing trunk motion.     

Classification versus inference learning contrasted with real-world categories

Categories are learned and used in a variety of ways, but the research focus has been on classification learning. Recent work contrasting classification with inference learning of categories found important later differences in category performance. However, theoretical accounts differ on whether this is due to an inherent difference between the tasks or to the implementation decisions. The inherent-difference explanation argues that inference learners focus on the internal structure of the categories—what each category is like—while classification learners focus on diagnostic information to predict category membership. In two experiments, using real-world categories and controlling for earlier methodological differences, inference learners learned more about what each category was like than did classification learners, as evidenced by higher performance on a novel classification test. These results suggest that there is an inherent difference between learning new categories by classifying an item versus inferring a feature.     

Is the principle of minimization of secondary moments validated during various fingertip force production conditions?

During the application of fingertip forces with simultaneous flexion of the four fingers, namely index, middle, ring, and little fingers, a stable force sharing among fingers is adopted. Several studies have hypothesized that this stable force sharing is established to minimize unnecessary rotational moments (different from the main flexion moments). This principle labeled "minimization of secondary moments" is presented in the literature as a principle used by the central nervous system to solve musculoskeletal redundancy. However, this principle has only been tested with one solicited degree of freedom and in one finger posture. Our study tests this principle with various degrees of freedom solicited as secondary moments and in two different finger postures. Participants (n=6) were asked to apply a downward vertical force using their four fingers with the forearm placed in two different configurations: a "horizontal" condition (involving flexion/extension and pronation/supination at the wrist joint) and a "vertical" condition (involving flexion/extension and radial/ulnar deviation at the wrist joint). Additionally, two finger postures were tested in each forearm configuration: in the first, the distal inter-phalangeal joints (DIP) were extended and the proximal inter-phalangeal joints (PIP) highly flexed. In the second finger posture, both DIP and PIP joints were flexed. The resultant four-finger force and the relative involvement of each finger in the resultant four-finger force (force sharing) were analyzed. Results showed that the finger postures did not influence the finger force sharing, showing that the minimization of the secondary moment principle was stable among the finger joint angle configurations. Nonetheless, the relative involvement of each finger was dependent on the secondary degree of freedom solicited (pronation/supination vs. radial/ulnar). The modifications of the finger force sharing between the "horizontal" and "vertical" conditions were in accordance with the principle of minimization of the secondary moments.     

Domains and knowledge effects: strategies in object and social classification

This research examined differences in classification strategies in object and social domains. Wattenmaker (1995) found that additive classification rules were more compatible with the social than the object domain. The present experiments examined the generality of these results by using fundamentally different types of social and object categories. A sorting paradigm was used to evaluate the frequency with which subjects used additive strategies. In Experiment 1, the social domain was represented by social events that possess very different properties than core social concepts such as traits or occupations. Even with these types of social materials, however, many more additive strategies and family resemblance sorts occurred with social than object materials. In Experiment 2, the object domain was represented by abstract object categories that were designed to possess properties of core social concepts such as traits. Again, however, more additive strategies and family resemblance sorts occurred with social than object materials. The results indicate that differences in the compatibility between additive strategies and object and social domains are not limited to subsets of categories in these domains but rather extend to many types of object and social categories.     

Individual differences in process outcomes for verbal analogy and classification solution

Adult performance on verbal analogy and classification problems was assessed in terms of the outcomes of process execution. Measures were obtained for the accuracy of stem processing and subsequent alternative processing. The process-outcome measures obtained within each task accounted for overall performance scores and were differentially related to ability. This was shown by ability differences in the models accounting for subjects' overall accuracy and in the correlational patterns. Analogy and classification problem forms differed in the measures most important for predicting individual differences. Specifically, measures of alternative processing were more important in classification than analogy solution and application was shown to be important for analogy solution. In addition, common process-outcome measures showed the highest correlations across problem forms, consistent with the assumption that both induction tasks tap similar psychological processes. The results are discussed with respect to previous studies assessing commonality and individual differences among children in process-outcomes.     

Electrographic correlates of lateral asymmetry in the processing of verbal and nonverbal auditory stimuli

A veraged evoked potentials (AEP) to verbal (digits) and nonverbal (clicks) auditory stimuli were recorded from left and right temporal leads in ten right-handed Ss. With dichotic presentation, there was no significant difference in accuracy of report of the clicks heard in each ear, but significantly more digits were identified correctly from the right ear than from the left. Dichotic verbal stimuli elicited AEP whose early components were of greater amplitude, and whose later components were of shorter latency, from the left hemisphere than from the right. No consistent latency or amplitude differences were observed between AEP from the left and right hemispheres when clicks were presented dichotically.     

Controlling velocity in rapid movements

It has often been reported that subjects prefer to use a strategy in which they vary movement velocity and peak amplitude in a linear fashion. In this study, control of velocity and amplitude in rapid reciprocating movements of the interphalangeal joint of the thumb was investigated by examining movement trajectories and patterns of activity in the extensor pollicis longus (EPL) and flexor pollicis longus (FPL) muscles. In controlling either amplitude or peak flexion velocity without constraint, subjects always used a strategy in which peak extension velocity and peak flexion velocity had strong linear correlations with movement amplitude. When they were required to keep either amplitude or peak flexion velocity fixed their movements were still biased toward a strategy in which peak velocity and movement amplitude covaried. It is suggested that the preferred strategy is related to a basic principle of scaling the magnitude and duration of a velocity profile in order to achieve different movement amplitudes.     

Adaptive Dynamics of the Leg Movement Patterns of Human Infants: I. The Effects of Posture on Spontaneous Kicking

This is the first of two articles in which we describe how infants adapt their spontaneous leg movements to changes in posture or to elicitation of behaviors by a mechanical treadmill. In this article, we compare the kinematics of kicks produced by 3-month-old infants in three postures, supine, angled (45°), and vertical, and examine the changes in muscular and nonmuscular force contributions to limb trajectory. By manipulating posture we were able to assess the sensitivity of the nascent motor system to changes in the gravitational context. The postural manipulation elicited a distinct behavioral and dynamic effect. In the more upright postures, gravitational resistance to motion at the hip was 4 to 10 times greater than resistance met in the supine posture, necessitating larger muscle torques to drive hip flexion. Kicks produced in the vertical posture showed a reduction in hip joint range of motion and an increase in synchronous joint flexion and extension at the hip and knee. At the same time, hip and knee muscle torques were also more highly correlated in kicks performed in the vertical than in the supine or angled posture. This increased correlation between muscle torques at the hip and knee implicates anatomical and energetic constraints—the intrinsic limb dynamics—in creating coordinated limb behavior out of nonspecific muscle activations.     

Adaptive Dynamics of the Leg Movement Patterns of Human Infants: I. The Effects of Posture on Spontaneous Kicking

This is the first of two articles in which we describe how infants adapt their spontaneous leg movements to changes in posture or to elicitation of behaviors by a mechanical treadmill. In this article, we compare the kinematics of kicks produced by 3-month-old infants in three postures, supine, angled (45 degrees ), and vertical, and examine the changes in muscular and nonmuscular force contributions to limb trajectory. By manipulating posture we were able to assess the sensitivity of the nascent motor system to changes in the gravitational context. The postural manipulation elicited a distinct behavioral and dynamic effect. In the more upright postures, gravitational resistance to motion at the hip was 4 to 10 times greater than resistance met in the supine posture, necessitating larger muscle torques to drive hip flexion. Kicks produced in the vertical posture showed a reduction in hip joint range of motion and an increase in synchronous joint flexion and extension at the hip and knee. At the same time, hip and knee muscle torques were also more highly correlated in kicks performed in the vertical than in the supine or angled posture. This increased correlation between muscle torques at the hip and knee implicates anatomical and energetic constraints-the intrinsic limb dynamics-in creating coordinated limb behavior out of nonspecific muscle activations.     

身体姿势的心理效应：基于具身视角

具身视角下，姿势可以对心理产生影响。梳理了广受关注的“直立”和“蜷曲”、“扩张”和“收缩”、“水平”和“垂直”等姿势的效应研究成果，并对神经肌肉反馈理论、自我知觉理论、情境认知理论等姿势效应的内在机制进行总结和评价。指出在实验范式、姿势控制、效应稳定性以及深层机制探析等方面存在的局限和未来方向，认为姿势效应的神经机制、时程变化、个体差异及姿势的心理调节功能等将会成为研究热点。