Practice Effects in Bimanual Force Control: Does Age Matter?

ABSTRACT

The authors examined age-related differences in fine motor control during a bimanual coordination task. The task required the modulation of fingertip forces in the precision grip according to a visually presented sinusoidal antiphase pattern (force range 2–12 N; frequency 0.2 Hz). Thirty-four right-handed participants of three age groups (young, early middle-aged, and late middle-aged) practiced 30 trials of the task. Accuracy and variability of relative timing and relative forces at minima and maxima of the sine wave were analyzed for hand–hand and hand–stimulus couplings and compared between age groups. Analysis showed for relative timing and force weaker hand–hand than hand–stimulus coupling as well as lower accuracy and higher variability for minima as compared to maxima. Further, we analyzed practice effects by comparing the first and last trials and characterized the course of practice by detecting the transition of a steeper to a shallower acquisition slope for the different age groups. Late middle-aged participants demonstrated poorer performance than both other groups for all parameters. All groups improved performance to a similar amount. However, an age-related difference in acquisition strategy is visible. Late middle-aged participants seemed to have focused on improvement of force amplitude, whereas young and early middle-aged focused on timing.     

Does Task Affordance Moderate Age-related Deficits in Strategy Production?

ABSTRACT

According to the task-affordance hypothesis, people will be more likely to use a specific strategy as tasks more readily afford its use. To evaluate this hypothesis, we examined the degree to which older and younger adults used a self-testing strategy to learn items, because previous studies suggest that age-related differences in the use of this powerful strategy vary across tasks. These tasks (words affixed to a board vs. pairs on flashcards) differentially afford the use of the self-testing strategy and may moderate the age-related effects on strategy use. Participants performed a recall-readiness task in which they continued to study items until they were ready for the criterion test. As predicted, self testing was used less often on tasks that least afforded its use. Namely, participants used self testing less when they studied single words affixed to a board than when they studied pairs on flashcards. Most important, age-related deficits in strategy use were greater for the former task and nonexistent for the latter one, suggesting that task affordance moderates age differences in strategy use.     

Does Life Satisfaction Determine Subjective Health?

The majority of previous studies on life satisfaction and health status were conducted in the advanced developed countries, while less attention has been focused on transitional countries, especially those in Central Asia, the Caucasus, and the Balkans. This study is among a very few studies that focused on the regions which faced on the prolonged economic and political crisis during the transition. Drawing on comparable data from 28 transitional countries in Eastern and Central Europe, the Caucasus, the Central Asia, and Turkey, we quantify the effect of self-reported life satisfaction on the self-reported health status of the population. To rule out reverse causality and to reduce estimation biases, we employed simultaneous equation models with instrumental variables. Two models used standard simultaneous equation regression (2SLS) and bivariate ordered probit regression (bioprobit) for categorical ordered variables. Our main finding is that, regardless of the model used, higher levels of life satisfaction determine higher health status. The mechanisms regarding the effects of life satisfaction on health are discussed. Future researchers are encouraged to include life satisfaction in their analyses of health status. From a methodological standpoint, we demonstrate that a strong endogeneity exists between life satisfaction and health status, regardless of the models used. Ignoring endogeneity and estimating a single stage regression model with life satisfaction and health status will likely lead to biased results.     

Does Reading Words Differing in Arousal Load Influence Interference Control in Flanker Task?

Arousal involves a physiological and psychological state of being awake or reactive to stimuli. It could be treated also as an energetic property of stimulation. On the basis of previous findings concerning affective state modulation of spatial processing, I predict that arousal impact will follow the Yerkes-Dodson law. To test this hypothesis, 135 words were chosen and divided into three levels of arousal (low, medium and high), whilst controlling for valence, concreteness, frequency of appearance and length. Forty-nine individuals performed a flanker task while reading the words in order to provide a measure of interference control over spatial processing. The accuracy of answers, reaction times and interference effect index were analyzed. It appears that, at the medium arousal level of words, arousal was optimal for interference control, while both low and high arousal impaired the cognitive control of interference caused by competing flanker and target stimuli features.     

Bimanual reaching across the hemispace: Which hand is yoked to which?

When both hands perform concurrent goal-directed reaches, they become yoked to one another. To investigate the direction of this coupling (i.e., which hand is yoked to which), the temporal dynamics of bimanual reaches were compared with equivalent-amplitude unimanual reaches. These reaches were to target pairs located on either the left or right sides of space; meaning that in the bimanual condition, one hand's contralateral (more difficult) reach accompanied by the other hand's ipsilateral (easier) reach. By comparing which hand's difficult reach was improved more by the presence of the other hand's easier ipsilateral reach, we were able to demonstrate asymmetries in the coupling. When the cost of bimanual reaching was controlled for the contralateral reaching left hand's performance was improved, suggesting that the left hand is yoked to the right during motor output. In contrast, the right hand showed the greatest improvements for contralateral reaching in terms of reaction time, pointing toward a dominant role for the left hand in the processes prior to movement onset. The results may point toward a mechanism for integrating the unitary system of attention with bimanual coordination.     

Does luck have a place in epistemology?

Some epistemologists hold that exploration and elaboration of the nature of luck will allow us to better understand knowledge. I argue this is a mistake.     

Violations of Fitts’ Law in a Ballistic Task

ABSTRACT

The authors explored changes in the postural preparation and movement times during jumps into targets of different sizes placed at different distances from the participant. Both movement and preparation times scaled with movement distance. Neither movement nor preparation time showed an effect of target size, although preparation time showed a tendency to increase for smaller targets. These observations show that the classical Fitts’ law can be violated in tasks that involve a ballistic component. The data corroborate a hypothesis that Fitts’ law originates at the level of movement planning.     

Does a salient distractor capture attention early in processing?

Kim and Cave (1999) used spatial probes in order to measure the effects of bottom-up and top-down factors on the allocation of spatial attention over time. Subjects searched for a target with a unique shape, with a uniquely colored distractor present on each trial. The singleton distractor captured attention early in processing, whereas attention homed in on the target’s location later on. Kim and Cave (1999) concluded that top–down factors cannot prevent the presence of a salient distractor from delaying target selection. The present study tested the idea that such results were obtained only because subjects adopted the strategy of searching for the most salient item. Kim and Cave’s (1999) finding was replicated in Experiment 1. In Experiment 2, instead of a feature search, subjects performed a conjunction search—that is, a task that could not be performed using a salience–based strategy. Probe response times were longest at the salient distractor’s location at both the short and the long stimulus onset asynchronies. These results suggest that, early in processing, top–down factors can exert their influence and prevent the capture of attention by a salient distractor.     

Does background music in a store enhance salespersons' persuasiveness?

Background music has been studied as a key element of the store atmosphere in terms of its emotional effects; however, previous studies have shown also that music may have cognitive influence on consumers. How does music affect the salespersons' persuasive efforts within the store? To answer this question an experimental study was designed to assess the effects of four levels of arousing music conditions (no-low-moderate high arousing music). The level of pleasure of the musical pieces was controlled for. Music does not moderate significantly the effects of the salespersons on the intent to buy, but low and moderately arousing music (similarly low and moderately interesting musical pieces) does influence significantly the effects on the acceptance of the salesperson's arguments and the "desire to affiliate," i.e., to enter into communication.     

Does psychology make a significant difference in our lives?

The intellectual tension between the virtues of basic versus applied research that characterized an earlier era of psychology is being replaced by an appreciation of creative applications of all research essential to improving the quality of human life. Psychologists are positioned to "give psychology away" to all those who can benefit from our wisdom. Psychologists were not there 35 years ago when American Psychological Association (APA) President George Miller first encouraged us to share our knowledge with the public. The author argues that psychology is indeed making a significant difference in people's lives; this article provides a sampling of evidence demonstrating how and why psychology matters, both in pervasive ways and specific applications. Readers are referred to a newly developed APA Web site that documents current operational uses of psychological research, theory, and methodology (its creation has been the author's primary presidential initiative): www.psychologymatters.org.     

When is a map not a map? Task and language in spatial interpretation with digital map displays

Cognitive studies of map interpretation, for both paper‐based and digital maps (e.g. in geographic information systems), have generally assumed awareness of the map's geographic representational characteristics. However, many tasks using a digital map do not require visualization of the geographic environment it represents, but a conflicting focus on the geometric properties of the visual array. An experimental study demonstrated that the tasks performed and linguistic terms used with a digital map influenced the user's mental representation, as reflected by ease of orientation within the actual geographic environment (as measured by an unexpected photograph interpretation task). The map was still present during this task, since the concern was with interpretation rather than recall. No gender, age or expertise effects were found. Results are discussed with regard to the concept of reference frames and other spatial distinctions. Copyright © 2002 John Wiley & Sons, Ltd.     

Which reality in the psychoanalytic session?

The author discusses how the analyst's theory influences what happens in the psychoanalytic session, and, in particular, how it determines which of several possible realities become the focus of attention. An overview of Bionian thought and how it informs the author's way of working is provided. In elaborating his use of the narrative level in the session and other key concepts, the author presents three brief clinical vignettes.     

Does directed exploration influence locomotor activity in a holeboard test?

The effects of three drugs, chosen for their differential effects on directed exploration and locomotion (ethanol, caffeine, and FG 7142), were examined on the locomotor activity of mice in a holeboard apparatus containing either a solid floor or one with four holes in it. The dose-related effect of all three drugs on locomotor activity was not changed by the presence of the holes, although activity was slightly higher when a solid floor was used. The results indicated that the two measures can vary independently and that the directed exploration component (head-dipping) of the holeboard test does not significantly influence the locomotor activity component.     

Does handedness determine which hand leads in a bimanual task?

Right- and left-handers (n = 16 in each group) were tested on a bimanual circle task that required drawing either in the same direction (parallel) or in a mirror symmetrical coordination mode with the two hands. The authors' primary purposes were to examine the effect of circle direction on within-hand and between-hands variables and to determine whether the relation between hand lead and coordination mode (parallel or mirror symmetrical) differs for left- and right-handers. A strong relation was found between lead hand and movement condition, which depended on the direction of the movements and whether the task was parallel or mirror symmetrical. The pattern of results was similar for left- and right-handers on parallel tasks, but group differences were found with respect to mirror symmetrical tasks. At odds with the general claim that the dominant hand leads, the present results indicated that hand dominance does not generally determine which hand leads.     

Does retinal size have a unique correlate in perceived size?

Subjects estimated the size and distance of a single electroluminescent disc in the absence of distance cues and without the use of visual comparators. For different groups of Ss the disc subtended a visual angle of 1, 2, 4, or 8 deg. The size estimates varied directly with visual angle and the distance estimates varied inversely with visual angle. These results were considered in relation to the question of whether or not retinal size hasa direct correlate in perceived size.     

Does a cognitive map guide choices in the radial-arm maze?

Fifteen rats performed in a standard radial-arm maze task (Experiment 1) and in a modified task with a set of forced choices and a 15-min retention interval prior to completion of the maze (Experiment 2). In addition to the standard measure of choice in the radial-arm maze, orientation toward arms was measured and considered to constitute go-no-go "microchoice" decisions. Rats investigated but rejected many arms. A model of choice was developed in which it was assumed that choice decisions about arms were made independently and that microchoices were not selectively guided toward baited arms. The model performed nearly as well as the rats. These results place important limitations on the theory that choice behavior in the radial-arm maze is guided by a cognitive map.