EMG activity in selected target muscles during imagery rising on tiptoes in healthy adults and poststroke hemiparetic patients

The authors sought to gain further knowledge about activation of target muscles during imagery engagement in a motor task. Six hemiparetic patients and 9 healthy participants performed 3 real rises on tiptoes and then, after pausing, 3 imagery rises on tiptoes. Metronome beats guided the rate of rises and descents. Electromyographic (EMG) activity from the medial gastrocnemius and the rectus femoris muscles were monitored bilaterally throughout the performance of both tasks. In 3 healthy participants and 3 individuals with hemiparesis, EMG activity was related to the imagery task in at least 1 of the target muscles. Conversely, in the other participants, motor imagery practice was not accompanied by task-related EMG activity in the monitored muscles. In all cases, the increment in activation level during motor imagery practice was very low in comparison with that of real performance. The findings were not unequivocal; therefore, EMG activity may sometimes, but not always, be recorded during motor imagery practice both in healthy individuals and in poststroke hemiparetic participants. Further research is needed to align motor imagery practice with the objectives of motor rehabilitation.     

Deconstructing, reconstructing, preserving Paul E. Meehl's legacy of construct validity

The question of the status of cause-and-effect explanations of human behavior that posit physically existing causative factors and those that, on the other hand, posit hypothetical entities in the form of "useful fictions" has a long history. The influence of the works of Jeremy Bentham and Hans Vaihinger, as well as the later influence of Francis Galton, is described. Issues of the validity of hypothetical constructs and related problems of measurement and definition as found in psychoanalytic theory construction and in trait theory are examined. The significant and continuing interest generated by the landmark studies of K. MacCorquodale and P. E. Meehl (1948) and L. J. Cronbach and P. E. Meehl (1955) as well as the central importance of P. E. Meehl's thinking are described.     

Changes in adolescent response patterns on the MMPI/MMPI--a across four decades

The purpose of this study was to explore changes in adolescent self-presentation on the Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1940) and MMPI-A (Butcher et al., 1992) over a 40-year period. The primary samples used for comparison in this study include 1,235 adolescents, age 14 through 16, derived from the MMPI-A normative sample (Butcher et al., 1992) collected in 1989 and 10,514 adolescents, age 14 through 16, collected in 1948 and 1954 from Hathaway and Monachesi's (1963) study of adolescent personality and behavior. MMPI basic scale and item-level data were also included for 817 adolescents, age 14 through 16, collected by Colligan and Offord (1992) in 1985 as a further comparison. Between-sample analyses at the profile level revealed that adolescents from the MMPI-A normative sample scored significantly higher across basic clinical scales and lower on validity scales L and K than adolescents from the Hathaway and Monachesi (1963) sample, with mean data from the Colligan and Offord (1992) sample typically falling at a midpoint value. Analyses of Harris-Lingoes (Harris & Lingoes, 1955) subscale and item-level data were conducted to provide refined definitions of the contents of scale-level changes. Results were interpreted as reflecting moderate to large changes in response frequencies between eras of data collection, and emphasis was placed on the relatively high frequency of item endorsements by contemporary adolescents in the clinical direction in the MMPI-A normative sample. A series of cautions and limitations are also offered in interpreting these patterns.     

Voluntary and involuntary attention vary as a function of impulsivity

In the present study we examined, first, whether voluntary and involuntary attention manifest differently in people who differ in impulsivity (measured with the Barratt Impulsivity Scale). For Experiment 1, we used the spatial cueing task with informative and noninformative spatial cues to probe voluntary and involuntary attention, respectively. We found that participants with high impulsivity scores exhibited larger involuntary attention effects, whereas participants with low impulsivity scores exhibited larger voluntary attention effects. For Experiment 2, we used the correlated-flanker task to determine whether the differences between groups in Experiment 1 were due to high-impulsive participants being less sensitive to the display contingencies or to high-impulsive participants having a greater spread of spatial attention. Surprisingly, high-impulsive participants showed a greater sensitivity to contingencies in the environment (correlated-flanker effect). Our results illustrate one situation in which involuntary attention associated with high impulsivity can play a useful role.     

The multifinality constraints effect: how goal multiplicity narrows the means set to a focal end

In the presence of several objectives, goal conflict may be avoided via multifinal means, which advance all of the active goals at once. Because such means observe multiple constraints, they are fewer in number than the unconstrained means to a single goal. Five experimental studies investigated the process of choosing or generating such means for multiple goals. We found that the simultaneous activation of multiple goals restricted the set of acceptable means to ones that benefitted (or at least, did not harm) the entire set of active goals. Two moderators of this phenomenon were identified: (a) the feasibility of identifying multifinal means, which was dependent on the relations between the different active goals, and (b) the enhanced importance of the focal goal, which resulted in the inhibition of its alternatives and the consequent relaxation of multifinality constraints.     

Mechanisms of motivation–cognition interaction: challenges and opportunities

Recent years have seen a rejuvenation of interest in studies of motivation–cognition interactions arising from many different areas of psychology and neuroscience. The present issue of Cognitive, Affective, & Behavioral Neuroscience provides a sampling of some of the latest research from a number of these different areas. In this introductory article, we provide an overview of the current state of the field, in terms of key research developments and candidate neural mechanisms receiving focused investigation as potential sources of motivation–cognition interaction. However, our primary goal is conceptual: to highlight the distinct perspectives taken by different research areas, in terms of how motivation is defined, the relevant dimensions and dissociations that are emphasized, and the theoretical questions being targeted. Together, these distinctions present both challenges and opportunities for efforts aiming toward a more unified and cross-disciplinary approach. We identify a set of pressing research questions calling for this sort of cross-disciplinary approach, with the explicit goal of encouraging integrative and collaborative investigations directed toward them.     

Applying the Bootstrap to Taxometric Analysis: Generating Empirical Sampling Distributions to Help Interpret Results

Meehl's taxometric method was developed to distinguish categorical and continuous constructs. However, taxometric output can be difficult to interpret because expected results for realistic data conditions and differing procedural implementations have not been derived analytically or studied through rigorous simulations. By applying bootstrap methodology, one can generate empirical sampling distributions of taxometric results using data–based estimates of relevant population parameters. We present iterative algorithms for creating bootstrap samples of taxonic and dimensional comparison data that reproduce important features of the research data with good precision and negligible bias. In a series of studies, we demonstrate the utility of these comparison data as an interpretive aid in taxometric research. Strengths and limitations of the approach are discussed along with directions for future research.     

Self-Determination and Resource Rights: In Defence of Territorial Jurisdiction Over Natural Resources

Is territorial jurisdiction over natural resources justified? This paper argues that a freedom-based account of self-determination coupled with ‘functionalist’ justifications of territorial right support territorial jurisdiction over natural resources. This justification simultaneously gives rise to limits on the permissible exercise of the right: the principles of reciprocity and generality, and of equal freedom. This ‘reciprocal’ view on territorial jurisdiction over natural resources, defended here, differs from two alternatives: the traditional sovereignty view on the one hand and the transnational jurisdiction view—which favours the transfer of sovereignty over natural resources from states to transnational institutions—on the other hand.     

Relations Between the Development of Teaching and Theory of Mind in Early Childhood

The relations among children’s theory of mind (ToM), their understanding of the intentionality of teaching, and their own peer teaching strategies were tested. Seventy-five 3-, 4-, and 5-year-olds completed 11 ToM and understanding-of-teaching tasks. Subsequently, 30 of the children were randomly chosen to teach a peer how to play a board game, and their teaching strategies and levels of contingent teaching were recorded. There were developmental changes in the children’s understanding of teaching as an intentional activity. When teaching their peers, 3-year-olds used demonstration, whereas 4- and 5-year-olds added verbal explanations and began to adapt contingently to the learners’ changing knowledge level. Relations among ToM, understanding of teaching, and teaching level were found. The results suggest that the development of children’s teaching strategies and their contingency are closely tied to the development of ToM.