Preschoolers’ Motor and Verbal Self-Control Strategies During a Resistance-to-Temptation Task

Although prior research has shown that young children exhibit enhanced self-control when they use verbal strategies provided through adult instructions, little work has examined the role of children's spontaneous verbalizations or motor behavior as strategies for enhancing self-control. The present study examined the usefulness of spontaneous verbal and motor strategies for 39 3- and 4-year-old children's ability to exercise self-control during a resistance-to-temptation task. After a 2-min play period, participants were asked by an experimenter not to touch an attractive train set while he was out of the room. Children were videotaped during the 3-min waiting period and videos were coded for frequency and duration of touches, motor movements, and verbalizations. Results indicated that self-control was improved by using both motor and verbal strategies. Children who were unable to resist touching the forbidden toy used limited motor or verbal strategies. These findings add to the growing literature demonstrating the positive role of verbalizations on cognitive control and draw attention to motor behaviors as additional strategies used by young children to exercise self-control.     

Authoritarian reactions to terrorist threat: Who is being threatened,the Me or the We?

Endorsement of authoritarian attitudes has been observed to increase under conditions of terrorist threat. However, it is not clear whether this effect is a genuine response to perceptions of personal or collective threat. We investigated this question in two experiments using German samples. In the first experiment (N = 144), both general and specific authoritarian tendencies increased after asking people to imagine that they were personally affected by terrorism. No such effect occurred when they were made to think about Germany as a whole being affected by terrorism. This finding was replicated and extended in a second experiment (N = 99), in which personal and collective threat were manipulated orthogonally. Authoritarian and ethnocentric (ingroup bias) reactions occurred only for people highly identified with their national ingroup under personal threat, indicating that authoritarian responses may operate as a group‐level coping strategy for a threat to the personal self. Again, we found no effects for collective threat. In both studies, authoritarianism mediated the effects of personal threat on more specific authoritarian and ethnocentric reactions. These results suggest that the effects of terrorist threat on authoritarianism can, at least in part, be attributed to a sense of personal insecurity, raised under conditions of terrorist threat. We discuss the present findings with regard to basic sociomotivational processes (e.g., group‐based control restoration, terror management) and how these may relate to recent models of authoritarianism.     

Emotion and Motor Control: Movement Attributes Following Affective Picture Processing

The authors investigated the impact of emotion on the performance of a square-tracing task after participants (N = 40) were exposed to pleasant (P), unpleasant (U), and neutral (N) pictures. Physiological and self-report measures indexed affective valence and arousal. In Experiment 1, greater error followed exposure to 4 consecutive U images than exposure to 4 consecutive P images. Speed of performance did not vary as a function of valence. In Experiment 2, participants viewed 1 slide per trial within a modified exposure protocol. Speed of performance varied as a function of valence; faster performance followed U relative to P stimuli. Accuracy of performance did not vary between conditions. Corresponding self-report and physiological measures generally corroborated previous evidence. Findings collectively indicated that the length of exposure to affective stimuli mediates speed and accuracy of motor performance; compared with P stimuli, U stimuli led to either increased error (short exposure) or increased speed (multiple exposures). The authors conclude that brief and extended exposures to affective pictures have direct behavioral consequences, and they discuss the implications of that finding.     

EMG Activity in Selected Target Muscles During Imagery Rising on Tiptoes in Healthy Adults and Poststrokes 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.     

Modulation of Gait During Visual Adaptation to Dark

The authors investigated the modulation of gait during dark adaptation. Twenty-five women (mean age = 72 years, SD = 5 years) walked back and forth on an arbitrarily uneven walkway during normal lighting at speeds ranging from slow to fast. Participants then performed 20 trials at preferred speed after sudden reduction of lighting; the authors compared those trials with point estimates at equivalent speeds representing normal lighting. The authors estimated speed, cadence, mediolateral trunk acceleration, and mediolateral interstep trunk-acceleration variability for each trial. Participants compensated for sudden reduction of lighting by reducing their walking speed. Compared with performance at equivalent speeds during normal lighting, cadence, trunk acceleration, and interstep trunk-acceleration variability initially increased. All variables showed an asymptotic approximation toward normal values during 60-90 s of walking in subdued lighting. The authors suggest that the sudden transition from normal to marginal lighting, rather than marginal lighting itself, may challenge locomotor control.     

Reducing Knowledge of Results about Relative versus Absolute Timing: Differential Effects on Learning

The purpose of the present experiment was to examine further earlier suggestions that a reduced relative frequency of knowledge of results (KR) can enhance the learning of generalized motor programs (GMPs) but at the same time degrade parameter learning, compared with giving KR after every trial (Wulf & Schmidt, 1989; Wulf, Schmidt, & Deubel, 1993). In contrast to these earlier studies, here KR was given separately for relative timing and absolute timing. Subjects practiced three movement patterns that required the same relative timing but different absolute movement times. KR was provided on 100% or 50% of the practice trials for relative timing or absolute timing, respectively. In retention and transfer tests, the groups that had had 50% KR about relative timing demonstrated more effective learning of the relative-timing structure, that is, GMP learning, than the groups that had had 100% KR about relative timing. The KR frequency had no effect on parameterization during retention; yet, when transfer to a task with a novel overall duration was required, the groups given 100% KR about absolute timing were more accurate in parameterization than the groups provided with 50% KR about absolute timing. Thus, the reduced relative KR frequency enhanced GMP learning but had no beneficial effect, or even a degrading effect, on parameter learning. The differential effects of a reduced KR frequency on the learning of relative timing and absolute timing also provide additional support for the dissociation of GMP and parameterization processes.     

Motor Programming When Sequencing Multiple Elements of the Same Duration

Motor programming at the self-select paradigm was adopted in 2 experiments to examine the processing demands of independent processes. One process (INT) is responsible for organizing the internal features of the individual elements in a movement (e.g., response duration). The 2nd process (SEQ) is responsible for placing the elements into the proper serial order before execution. Participants in Experiment 1 performed tasks involving 1 key press or sequences of 4 key presses of the same duration. Implementing INT and SEQ was more time consuming for key-pressing sequences than for single key-press tasks. Experiment 2 examined whether the INT costs resulting from the increase in sequence length observed in Experiment 1 resulted from independent planning of each sequence element or via a separate "multiplier" process that handled repetitions of elements of the same duration. Findings from Experiment 2, in which participants performed single key presses or double or triple key sequences of the same duration, suggested that INT is involved with the independent organization of each element contained in the sequence. Researchers offer an elaboration of the 2-process account of motor programming to incorporate the present findings and the findings from other recent sequence-learning research.     

The Use of Prescanning in the Parameterization of Sequential Pointing and Reaching Movements

The accuracy of reaching movements improves when active gaze can be used to fixate on targets. The advantage of free gaze has been attributed to the use of ocular proprioception or efference signals for online control. The time course of this process, however, is not established, and it is unclear how far in advance gaze can move and still be used to parameterize subsequent movements. In this experiment, the authors considered the advantage of prescanning targets for both pointing and reaching movements. The authors manipulated the visual information and examined the extent to which prescanning of targets could compensate for a reduction in online visual feedback. In comparison with a conventional reaching/pointing condition, the error in pointing was reduced, the eye-hand lead decreased, and both the hand-closure time and the size of the maximum grip aperture in reaching were modulated when prescanning was allowed. These results indicate that briefly prescanning multiple targets just prior to the movement allows the refinement of subsequent hand movements that yields an improvement in accuracy. This study therefore provides additional evidence that the coordinate information arising from efference or ocular-proprioceptive signals can, for a limited period, be buffered and later used to generate a sequence of movements.     

Challenge Point: A Framework for Conceptualizing the Effects of Various Practice Conditions in Motor Learning

The authors describe the effects of practice conditions in motor learning (e.g., contextual interference, knowledge of results) within the constraints of 2 experimental variables: skill level and task difficulty. They use a research framework to conceptualize the interaction of those variables on the basis of concepts from information theory and information processing. The fundamental idea is that motor tasks represent different challenges for performers of different abilities. The authors propose that learning is related to the information arising from performance, which should be optimized along functions relating the difficulty of the task to the skill level of the performer. Specific testable hypotheses arising from the framework are also described.     

Beyond Curve Fitting to Inferences About Learning

In this commentary, the authors elaborate on the issue of going beyond curve fitting to the drawing of inferences about motor learning. They argue that the agenda of A. Heathcote and S. Brown (2004) is largely a theory-free, curve-fitting enterprise that can be useful for certain aspects of describing behavior change, but that its gold standard of percentage of variance accounted for can also be misleading in its relevance to the theory of learning. Clearly, analysis methods are necessary and some are better than others, but the researcher can more fully exploit the relevance of methods to the construct with a priori theorizing than with a data-driven strategy of maximizing percentage of variance accounted for in curve fitting.