Effects of concurrent physical and cognitive demands on arm movement kinematics in a repetitive upper-extremity precision task

The effect of concurrent physical and cognitive demands on arm motor control is poorly understood. This exploratory study compared movement kinematics in a repetitive high-precision pipetting task with and without additional concurrent cognitive demands in the form of instructions necessary to locate the correct target tube. Thirty-five healthy female subjects performed a standardized pipetting task, transferring liquid repeatedly from one pick-up tube to different target tubes. In the reference condition, lights indicated the target tube in each movement cycle, while the target tube had to be deciphered from a row and column number on a computer screen in the condition with additional cognitive demands. Kinematics of the dominant arm was assessed using the central tendency and variability of the pipette-tip end-point trajectory and joint kinematics properties of the shoulder and elbow. Movements slowed down (lower velocities and higher area under the movement curves) and trajectory variability increased in the condition with additional cognitive demands, but there were no changes in the kinematics properties such as joint range of motion, times of acceleration and deceleration (as indicated by the time to peak velocity), average angles, or phase relationships between angle and angular velocity of shoulder or elbow movements between the two conditions. Further, there were also no differences in the size or structure of variability of the shoulder and elbow joint angles, suggesting that subjects could maintain the motor repertoire unaltered in the presence of these specific additional cognitive demands. Further studies should address motor control at other levels of concurrent cognitive demands, and with motor tasks that are less automated than the pipetting task used in the present study, so as to gain an increased understanding of the effect of concurrent cognitive demands for other activities of relevance to daily life.     

Work demands and resources and the work–family interface: Testing a salience model on German service sector employees

The present study tested an extended version of Voydanoff's “differential salience vs. comparable salience model” in a sample of German service workers. Our findings partially support the model in a different national/cultural context but also yielded some divergent findings with respect to within-domain resources and boundary-spanning demands. In line with the theoretical framework, work-to-home interference (WHI) mainly occurred because of high work demands and not because of a lack of work resources. Boundary-spanning resources yielded comparable potential to reduce WHI and enhance work-to-home enrichment (WHE). WHE was expected to more likely occur due to the activation of work resources rather than the absence of work demands. However, control over one's work did not have a significant impact on WHE. In addition and contrary to the theoretical model, boundary-spanning demands were found to be differentially rather than comparably salient to the work–family interface.     

Word recognition in child second language learners: Evidence from cognates and false friends

We studied how Dutch children learned English as a second language (L2) in the classroom. Learners at different levels of L2 proficiency recognized words under different task conditions. Beginning learners in primary school (fifth and sixth grades) and more advanced learners in secondary school (seventh and ninth grades) made lexical decisions on words that are similar for English and Dutch in both meaning and form (“cognates”) or only in form (“false friends”). Cognates were processed faster than matched control words by all participant groups in an English lexical decision task (Experiment 1) but not in a Dutch lexical decision task (Experiment 2). An English lexical decision task that mixed cognates and false friends (Experiment 3) led to consistently longer reaction times for both item types relative to controls. Thus, children in the early stages of learning an L2 already activate word candidates in both of their languages (language-nonselective access) and respond differently to cognates in the presence or absence of false friends in the stimulus list.     

Juggling Parent Care and Employment Responsibilities: The Dilemmas of Adult Daughter Caregivers in the Workforce

We review findings from our programmatic research on adult daughters who are simultaneously involved in the roles of employee and care provider to an impaired parent. Two opposing theoretical perspectives on the health effects of occupying these two roles are described, and empirical findings that bear on each perspective are presented. Our review reveals that, consistent with the competing demands perspective, parent care and employment often conflict with one another. Consistent with the energy expansion perspective, however, there is evidence that holding these two roles can be beneficial for the health of adult daughters.     

After images and pain tolerance: a descriptive study on their interrelationship

After images are based on physiological processes, they can also be treated as subjective phenomena with a psychological meaning. This statement also applies to pain. The basic working hypothesis of this study concerned the relationship between the two phenomena. Forty-one respondents (23 females, 18 males, age range 20-45 years) were given the Cold Pressor Test and the Serial After Image Technique. The data analysis was done by means of cross-tables and an exploratory optimal scaling program (OVERALS). Three pain tolerance groups (low, medium, high) could be differentiated fairly well on the basis of the after image characteristics of the respondents. Pain intolerant respondents more frequently had small and "immature" after images, whereas highly pain tolerant respondents had more large and "mature" after images. The implications of these results for a bio-psycho-social theoretical frame of reference for pain are discussed.     

Coping and the Job Demands-Control-Support Model: An Exploratory Study

The job demands-control-support model indicates job control and social support enhance coping with job demands. This proposition was tested, using a heterogeneous sample of 272 full-time workers. The results indicated a series of complex interactions among demands, control, support, and coping on psychological well-being. Overall, control and support appeared to increase the effectiveness of problem-focused coping and emotion-focused coping up to a threshold depending on job demands. The results indicate that beyond this threshold, these forms of coping become less effective. Control appeared to enhance moderate levels of appraisal and cognitive escape-focused coping, but not high levels of appraisal or cognitive escape-focused coping. Social support appeared to enhance high levels of appraisal-focused coping. The results indicate that including coping in empirical tests of the job demands-control-support model enhances its explanatory and predictive power.     

TASK DIFFICULTY AND ABERRANT BEHAVIOR IN SEVERELY HANDICAPPED STUDENTS

The influence of task difficulty on aberrant behavior was investigated with three severely handicapped students. Noticeably higher rates of problem behavior occurred in demand compared to no-demand conditions. In addition, there were higher rates of problem behaviors on difficult versus easy tasks. Both these findings were validated with visual discrimination and perceptual motor tasks. An errorless learning procedure effectively minimized errors and aberrant behavior in visual discrimination tasks but not in perceptual motor tasks. It was conceptualized that aberrant behavior was maintained by negative reinforcement contingencies. Difficult tasks were aversive to the children, who emitted aberrant responses to escape or avoid such tasks. By contrast, conditions in which no demands were made, easy tasks, and, in visual discrimination learning, errorless tasks, were less aversive and resulted in little or no problem behavior. Implications for reducing maladaptive behaviors through curricular modifications are discussed and contrasted to more traditional consequence manipulation approaches.     

Obligatory and optional personal life investments in old and very old age: Validation and functional relations

Personal life investment (PLI) measures motivational energy invested in central life domains. We distinguished between obligatory PLIs, that is, required investments, and optional PLIs, that is, investments that are possible but not necessary. Data from the Berlin Aging Study (N = 516; 70–103 years) were employed to investigate the validity of this distinction. We further explored how both PLI types relate to aging satisfaction and whether associations with validation variables and satisfaction differed depending on resource limitations (poor health). As expected based on conceptual affinities between the distinctions of obligatory-optional PLI and approach-avoidance tendencies, both PLI types showed positive relations with extraversion (a correlate of approach), but only obligatory PLI was positively related to neuroticism (a correlate of avoidance). Optional PLI (not obligatory PLI) was related to higher aging satisfaction, but only in fairly healthy people. This underscores differential functional relations of optional PLI depending on resource availability.

Compliance, conversion, and category induction

When children hear an object referred to with a label that is moderately discrepant from its appearance, they frequently make inferences about that object consistent with the label rather than its appearance. We asked whether 3-year-olds actually believe these unexpected labels (i.e., conversion) or whether their inferences simply reflect a desire to comply with the considerable experimental demands of the induction task (i.e., compliance). Specifically, we asked how likely children would be to pass an unexpected label on to another person who had not been present during the labeling event. Results showed that children who used an unexpected label as the basis for inference passed that label on to another person about as often as they could remember it. This suggests that children’s label-based inferences do reflect conversion rather than mere compliance.