The costs of taking it slowly: fast and slow movement timing in older age

We investigated adult age-differences in timing control of fast vs. slow repetitive movements using a dual-task approach. Twenty-two young (M = 24.23 yr) and 22 older adults (M = 66.64 yr) performed three cognitive tasks differing in working memory load and response production demands and they tapped series of 550-ms or 2100-ms target intervals. Single-task timing was comparable in both groups. Dual-task timing was characterized by shortening of produced intervals and increases in drift and variability. Dual-task costs for both cognitive and timing performances were pronounced at slower tapping tempos, an effect exacerbated in older adults. Our findings implicate attention and working memory processes as critical components of slow movement timing and sources of specific challenges thereof for older adults.     

Children's memory for the duration of a paediatric consultation

To learn about children's ability to estimate the duration of an event many days after it occurred, 6–12‐year‐old children were asked to judge the amount of time (range 5–45 minutes) they spent in the treatment room as part of a paediatric visit. Judgements were made 1 week or 1 month after the visit occurred. Children showed an average error of about 13 minutes. Retention interval did not significantly affect estimates. Other judgements of the length of the interview itself (mean length 8 minutes) provided what may be the first data on children's ability to make immediate retrospective duration estimates. The results also include information about children's capacity to judge how long ago they visited the clinic. Copyright © 2009 John Wiley & Sons, Ltd.     

Imagery encoding and false recognition errors: Examining the role of imagery process and imagery content on source misattributions

Imagery encoding effects on source-monitoring errors were explored using the Deese-Roediger-McDermott paradigm in two experiments. While viewing thematically related lists embedded in mixed picture/word presentations, participants were asked to generate images of objects or words (Experiment 1) or to simply name the items (Experiment 2). An encoding task intended to induce spontaneous images served as a control for the explicit imagery instruction conditions (Experiment 1). On the picture/word source-monitoring tests, participants were much more likely to report "seeing" a picture of an item presented as a word than the converse particularly when images were induced spontaneously. However, this picture misattribution error was reversed after generating images of words (Experiment 1) and was eliminated after simply labelling the items (Experiment 2). Thus source misattributions were sensitive to the processes giving rise to imagery experiences (spontaneous vs deliberate), the kinds of images generated (object vs word images), and the ways in which materials were presented (as pictures vs words).     

A new solution to the problem of luck

The issue of whether and how we have the control necessary for freedom and moral responsibility is central to all control accounts of freedom and moral responsibility. The problem of luck for libertarians aims to show that indeterministic agents are ill-equipped with the control required for freedom and moral responsibility. In view of this, we must either endorse scepticism about the possibility of free and morally responsible agents, or make some form of, possibly revisionary, compatibilism work. In this paper, I shall offer a new solution to the problem of luck for libertarians. After outlining the problem of luck, I shall argue that, given a particular approach to mental causation, indeterminism can be viewed as an essential requirement of free and morally responsible action. After this, I shall distinguish between different types of inability and show how this provides us with a solution to the problem of luck. Finally, I shall consider some advantages and objections to the proposed solution.     

Understanding the Covariation Among Childhood Externalizing Symptoms: Genetic and Environmental Influences on Conduct Disorder,Attention Deficit Hyperactivity Disorder,and Oppositional Defiant Disorder Symptoms

Conduct disorder (CD), attention deficit hyperactivity disorder (ADHD), and oppositional defiant disorder (ODD) are common childhood externalizing disorders that frequently co-occur. However, the causes of their comorbidity are not well understood. To address that question, we analyzed data from > 600 Finnish twin pairs, who completed standardized interviews at age 14. Behavior genetic methods were used to examine how genetic/environmental factors contribute to each disorders symptoms and to their covariation. We found significant genetic effects on each disorder with only modest evidence of shared environmental influences. Our data suggest the comorbidity among CD, ADHD, and ODD is primarily explained by shared genetic influences; however, each disorder was also under unique genetic influence, supporting the distinction of each disorder.     

Disconfirmation and dual hypotheses on a more difficult version of wason's 2-4-6 task

This paper reports two experiments in which subjects worked to solve a more difficult version of Wason's 2-4-6 task: instead of the usual “numbers must ascend in order of magnitude” rule, a more general rule, “the three numbers must be different”, was used. The first experiment established that instructing subjects to disconfirm on the “three different numbers” did not significantly improve their performance, as compared with confirmatory and control groups. Disconfirmatory subjects did try to propose more triples at variance with their hypotheses but were unable to obtain the necessary disconfirmatory information.

To help subjects represent the task in a way that facilitated disconfirmation, the second experiment utilized a procedure in which subjects were told that they were looking for two rules, Dax and Med-the Dax rule corresponding to “three different numbers” and the Med rule to its complement, i.e. two or more numbers the same. Of subjects in the Dax-Med condition, 88% solve the rule, as opposed to 21% of subjects in a control condition. Dax-Med subjects tended to search for positive instances of the Med rule, which, in turn, forced them to test the limits of the Dax rule. It was concluded that the Dax-Med manipulation did facilitate a different mental representation of the task than the normal procedure.     

LEISURE-DANCE INSTRUCTION FOR SEVERELY AND PROFOUNDLY RETARDED PERSONS: TEACHING AN INTERMEDIATE COMMUNITY-LIVING SKILL

We evaluated an approach for teaching an intermediate community living skill via a leisure-dance activity to institutionalized severely and profoundly retarded persons. The targeted skill was considered as intermediate in contrast to a community living skill per se because it was based on successful performances of higher functioning, noninstitutionalized retarded persons as opposed to nonhandicapped individuals. Definitions for appropriate dancing were established and then validated through observations of the performance of retarded persons living in the local community. The dance skills were then taught to four participants through serial training in leg movements, arm movements, and coordinated leg and arm movements, plus follow-up trainer supervision. Generalization was also programmed by way of multiple trainers and training settings. Results during structured assessments showed that all four residents acquired the dance skills and that both serial training and follow-up supervision were necessary for skill acquisition. Generalized increases in appropriate dancing at dances attended by the participants and retarded persons from the community were also demonstrated. However, in most cases some active supervision by caregivers was needed to enhance the generalized improvements. Results are discussed in terms of the applicability of this approach for validating goals when training other community-related skills to low-functioning populations.