Period Duration of Physical and Im aginary Movement Sequences Affects Contralateral Amplitude Modulation

The hypothesis was tested that the strength of cross-manual effects of voluntary amplitude modulations in bimanual tasks increases when less preparation time is available during the execution of a sequence of movements. By means of the continuation procedure, various period durations (600, 800, 1200, and 1800 msec) of movement sequences were imposed. Subjects performed bimanual periodic arm movements on two digitizers: constant-amplitude movements (short or long) with the one hand, and movements of constant short or constant long amplitudes and movements of alternating short and long amplitudes with the other hand. Period-duration-dependent modulations of the amplitude were observed in movements of instructed constant amplitudes when the other hand performed alternating-amplitude movements, but not when the other hand performed constant-amplitude movements. Not only physical performance, but also the imaginary production of alternating-amplitude movements resulted in period-duration-dependent cross-manual effects, though reduced in size. The pattern of results is in agreement with a recently proposed two-level model of cross-manual effects according to which cross-talk can occur at the programming level as well as at the execution level.     

Investigating the Constrained Action Hypothesis: A Movement Coordination and Coordination Variability Approach

The purpose of this study was to examine the effects of focus of attention cues on movement coordination and coordination variability in the lower extremity. Twenty participants performed the standing long jump under both internal and external focus of attention conditions. A modified vector coding technique was used to evaluate the influence of attentional focus cues on lower extremity coordination patterns and coordination variability during the jumps. Participants jumped significantly further under an external focus of attention condition compared with an internal focus of attention condition (p = .035, effect size = .29). Focus of attention also influenced coordination between the ankle and knee, F(6, 19) = 2.87, p = .012, effect size = .388, with participants primarily using their knees under the internal focus of attention, and using both their ankles and knees under the external focus of attention. Attentional focus cues did not influence ankle-knee, F(1, 19) = 0.02, p = .98, effect size = .02, or hip-knee, F(1, 19) = 5.00, p = .49, effect size = .16, coordination variability. Results suggest that while attentional focus may not directly influence movement coordination condition, there is still a change in movement strategy resulting in greater jump distances following an external focus of attention.     

Solitude without Souls: Why Peter Unger hasn’t Established Substance Dualism

Unger has recently argued that if you are the only thinking and experiencing subject in your chair, then you are not a material object. This leads Unger to endorse a version of Substance Dualism according to which we are immaterial souls. This paper argues that this is an overreaction. We argue that the specifically Dualist elements of Unger’s view play no role in his response to the problem; only the view’s structure is required, and that is available to Unger’s opponents. We outline one such non-Dualist view, suggest how to resolve the dispute, respond to some objections, and argue that ours is but one of many views that survive Unger’s challenge. All these views are incompatible with microphysicalism. So Unger’s discussion does contain an insight: if you are the only conscious subject in your chair, then microphsyicalism is false. Unger’s mistake was to infer Substance Dualism from this; for microphysicalism is not the only alternative to Dualism.     

Contextual interference and augmented feedback: is there an additive effect for motor learning?

Learning to perform a skilled behavior is affected by the context of the practice session and the frequency of augmented feedback. We studied the combined effect of these variables in the acquisition of a ballistic, bi-directional lever movement pattern involving four different target locations as measured by performance in practice, retention, and transfer tests. Augmented feedback was presented in either an every-trial or a faded schedule during random and blocked practice. Consistent with the contextual interference effect, the blocked practice group produced lower errors in acquisition, but the random practice group outperformed the blocked practice group in both retention and transfer. In contrast, faded feedback did not have a beneficial effect on learning and degraded learning when provided during blocked practice. While the results were consistent with previous findings of random and blocked practice, they were not consistent with previous findings of reduced feedback frequencies.     

Do hospital treatments represent a 'teachable moment' for quitting smoking? A study from a stage-theoretical perspective

Hospital treatments are assumed to be a 'teachable moment'. This phenomenon, however, is only poorly conceptualised and untested. A stage-theoretical perspective implies that a cueing event such as hospital treatments is a teachable moment if a stage progression, change of cognitions, or both occur. This concept is examined in a cross-sectional study by comparing smokers in two treatment settings, an emergency department (ED) and inpatient treatment after elective surgery, with smokers in a control setting. Setting differences were hypothesised in stage distribution, and levels of and stage differences in social-cognitive factors under control for possible confounders. Stage, social-cognitive factors and possible confounders were assessed in 185 ED smokers, 193 inpatient smokers and 290 control smokers. Compared to control smokers, ED and inpatient smokers were in higher stages; they perceived fewer risks and cons; inpatient smokers reported more concrete plans. Stage differences in self-efficacy among ED and inpatient smokers differed from those among control smokers, but the former corresponded more strongly to the theoretical stage assumptions. The results suggest that hospital treatments lead to a stage progression and change of corresponding cognitions, and thus represent a 'teachable moment'. Stage-matched interventions should be provided but consider differences in cognitions to be effective.     

Being Successful in a Creative Profession: The Role of Innovative Cognitive Style, Self-Regulation, and Self-Efficacy

Purpose  

The purpose of this study was to test a model that proposes that innovative cognitive style and self-regulation (setting priorities, planning work activities, and monitoring time and task progress) are related to the self-reported success of architects. We investigated two aspects of the success: as designers and as business people. To this end, we examined the mediating role of self-efficacy in these relationships.     

Preoperative enrichment and behavioral recovery in rats with septal lesions

To assess the behavioral effects of preoperative differential housing male rats were placed in either enriched or isolated environments at weaning prior to receiving either sham operations or septal lesions when 57 days of age. Rats with septal lesions showed reduced habituation of ambulation and initially made fewer rears in an empty open field but made more object-contacts coupled with a lack of habituation in the object-filled field. Septal rats also showed severe impairments when tested in a 12-arm radial maze with 7 arms baited and 5 arms unbaited. Preoperative enrichment did not significantly affect these lesion-induced changes. Nevertheless, enrichment significantly lowered ambulation (but did not affect habituation) in the open field and increased the number of manipulatory relative to nonmanipulatory contacts. However, preoperatively enriched septal rats showed a deficit in spontaneous alternation (45%) in contrast to the high levels (83%) shown by intact enriched rats, whereas both intact and septal isolated rats showed similar levels of spontaneous alternation (68%). These results conflict with earlier reports that preoperative enrichment "protects" rats against the deficits produced by septal lesions.     

Effects of physostigmine and d-amphetamine on the behavior of rats with selective fimbria-fornix lesions and intrahippocampal fetal septal cell transplants

Female Long-Evans rats were given electrolytic lesions of either the medial fimbria bilaterally (Fi, n = 24), the dorsal fornix (Fo, n = 24), or both structures (FF, n = 24) at 31 days of age. Ten rats were given sham-operations. Ten days later, half the rats with lesions received bilateral intrahippocampal grafts of embryonic septal cell suspensions (FiT, FoT, FFT, respectively). As already reported in a separate publication (J.C. Dalrymple-Alford, C.R. Kelche, J.C. Cassel, G. Toniolo, V. Pallage, & B.E. Will, 1987, Experimental Brain Research, 210, 115-128), 7 months after transplant surgery, grafted rats were found to be more impaired in an eight-arm radial maze than nongrafted rats. The present report concerns a pharmacological study carried out in the same rats 11 months after grafting. We examined the effects of ip injections of physostigmine (0.01, 0.05, 0.10 mg/kg) and then of d-amphetamine (1.6 mg/kg), as compared with baseline control injections of saline. Just prior to the drug treatments, performances of grafted and nongrafted rats did not differ significantly, but impairments in grafted rats reappeared during subsequent no-injection and saline control trials. Physostigmine failed to affect significantly the performances in rats of any group. d-Amphetamine improved performances in grafted rats with medial fimbria lesions, impaired performances in grafted rats with dorsal fornix lesions, and did not change performances in grafted rats with both lesions, as compared with their respective nongrafted counterparts. Histological analysis revealed variable reinnervation of the host structure and substantial graft-induced lesions of the hippocampus.(ABSTRACT TRUNCATED AT 250 WORDS)