Role of Constant,Random and Blocked Practice in an Electromyography-Based Oral Motor Learning Task

Purpose: The role of principles of motor learning (PMLs) in speech has received much attention in the past decade. Oral motor learning, however, has not received similar consideration. This study evaluated the role of three practice conditions in an oral motor tracking task.

Method: Forty-five healthy adult participants were randomly and equally assigned to one of three practice conditions (constant, blocked, and random) and participated in an electromyography-based task. The study consisted of four sessions, at one session a day for four consecutive days. The first three days sessions included a practice phase, with immediate visual feedback, and an immediate retention phase, without visual feedback. The fourth session did not include practice, but only delayed retention testing, lasting 10–15 minutes, without visual feedback.

Results: Random group participants performed better than participants in constant and blocked practice conditions on all the four days. Constant group participants demonstrated superior learning over blocked group participants only on day 4.

Conclusion: Findings indicate that random practice facilitates oral motor learning, which is in line with limb/speech motor learning literature. Future research should systematically investigate the outcomes of random practice as a function of different oral and speech-based tasks.     

Development of Spatial Language and Cognition in Hindi- and Sanskrit-Medium Schools

This paper describes a study carried out at Varanasi on the development of geocentric spatial cognition with 4–14 year old children of Hindi and Sanskrit medium schools. A number of tasks and procedures were used to assess the spatial frames of reference children used in describing and interpreting spatial displays. Analysis revealed that Sanskrit medium school children used more geocentric language and encoding than Hindi medium school children. The effect of age was significant only for encoding, not for language. Geocentric spatial cognition was significantly linked to fundamental spatial cognitive ability, as measured by Story-Pictorial Embedded Figures Test and Block Designs Test. The stronger expression of geocentric language and geocentric encoding in Sanskrit than Hindi medium school children suggests that the use of the ability can be sharpened by its practice and actualization in day-to-day life. The relationship between language and encoding was found to be of a moderate level suggesting that geocentric cognition is not determined by language alone, but also by other factors present in children’s eco-cultural contexts.     

Infants' perception of information along object boundaries: concavities versus convexities

Object parts are signaled by concave discontinuities in shape contours. In seven experiments, we examined whether 5- and 6 1/2-month-olds are sensitive to concavities as special aspects of contours. Infants of both ages detected discrepant concave elements amid convex distractors but failed to discriminate convex elements among concave distractors. This discrimination asymmetry is analogous to the finding that concave targets among convex distractors pop out for adults, whereas convex targets among concave distractors do not. Thus, during infancy, as during adulthood, concavities appear to be salient regions of shape contours. The current study also found that infants' detection of concavity is impaired if the contours that define concavity and convexity are not part of closed shapes. Thus, for infants, as for adults, concavities and convexities are defined more readily in the contours of closed shapes. Taken together, the results suggest that some basic aspects of part perception from shape contours are available by at least 5 months of age.     

Contrast and the justification of effort

When humans are asked to evaluate rewards or outcomes that follow unpleasant (e.g., high-effort) events, they often assign higher value to that reward. This phenomenon has been referred to ascognitive dissonance or justification of effort. There is now evidence that a similar phenomenon can be found in nonhuman animals. When demonstrated in animals, however, it has been attributed to contrast between the unpleasant high effort and the conditioned stimulus for food. In the present experiment, we asked whether an analogous effect could be found in humans under conditions similar to those found in animals. Adult humans were trained to discriminate between shapes that followed a high-effort versus a low-effort response. In test, participants were found to prefer shapes that followed the high-effort response in training. These results suggest the possibility that contrast effects of the sort extensively studied in animals may play a role in cognitive dissonance and other related phenomena in humans.     

Good continuation affects discrimination of visual pattern information in young infants

A familiarization-novelty preference procedure was used to determine whether 3- to 4-month-old and 6- to 7-month-old infants utilize the Gestalt principle of good continuation to organize visual patterns. The study involved presentation of a target item (i.e., a square or diamond) either in-line or off-line with a set of distractor items (i.e., circles). Infants in both age groups responded to a change in the target element in the off-line, but not in the in-line, condition. The results suggest that infants organize visual pattern information in accord with the principle of good continuation. Implications of this finding for models of the ontogenesis and microgenesis of object perception in infants and adults are discussed.     

The whole picture: Holistic body posture recognition in infancy

Holistic processing is tied to expertise and is characteristic of face and body perception by adults. Infants process faces holistically, but it is unknown whether they process body information holistically. In the present study, infants were tested for discrimination between body postures that differed in limb orientations in three conditions: in the context of the whole body, with just the isolated limbs that changed orientation, or with the limbs in the context of scrambled body parts. Five- and 9-month-olds discriminated between whole-body postures, but failed in the isolated-part and scrambled-body conditions, demonstrating holistic processing of information from bodies. These results indicate that at least some level of expertise in body processing develops quite early in life.     

Testing the Biobehavioral Family Model in pediatric asthma: pathways of effect

This study uses a laboratory-based multiinformant, multimethod approach to test the hypothesis that a negative family emotional climate (NFEC) contributes to asthma disease severity by way of child depressive symptoms, and that parent-child relational insecurity mediates the effect. Children with asthma (n = 199; aged 7-17; 55% male) reported parental conflict, parent-child relational security, and depressive symptoms. Parent(s) reported demographics, asthma history, and symptoms. Asthma diagnosis was confirmed by clinical evaluation and pulmonary function tests, with disease severity rated by an asthma clinician according to NHLBI guidelines. Family interactions were evoked using the Family Process Assessment Protocol, and rated using the Iowa Family Interaction Rating Scales. Path analysis indicated a good fit of data to the hypothesized model (chi2[1] = .11, p =.74, NFI = .99, RMSEA = .00). Observed NFEC predicted child depression (beta = .19, p < .01), which predicted asthma disease severity beta = .23, p < .01). Relational security inversely predicted depressive symptoms (p = -.40, p < .001), and was not a mediator as predicted, but rather an independent contributor. The findings are consistent with the Biobehavioral Family Model, which suggests a psychobiologic influence of specific family relational processes on asthma disease severity by way of child depressive symptoms.     

Perceptual organization based on illusory regions in infancy

Prior research indicates that, like adults, infants use enclosed regions to group elements. It is not clear whether infants or adults can use regions that have to be inferred from illusory contours to group elements. We examined whether 3- to 4-month-olds use illusory regions to group elements and generalize this organization to novel regions. Infants habituated to pairs of shapes in illusory vertical or horizontal regions subsequently discriminated, in novel regions, pairs of elements that had previously shared a region from pairs of elements that had been in different regions. A control group of infants, who had experienced the same stimuli except for the presence of illusory regions, failed to discriminate between within-region and between-region pairs of stimuli. These results reveal that (1) illusory regions can be used to group elements, (2) perceptual organization is sufficiently developed early in life for 3- to 4-month-olds to group on the basis of ecologically relevant illusory contours, and (3) such grouping in infancy generalizes to novel regions.     

The dynamics of standing balance

The control of standing is a complicated task that involves the action of muscles distributed over the whole body. Forces arising from gravity, external events or our own actions all tend to disturb the unstable equilibrium that preserves posture. For the central nervous system the problem of standing can be cast in terms of finding appropriate relations among body segments to maintain the desired position of the body as a whole with respect to the environment. In this review we evaluate some recent discoveries on the effects of predictable and unpredictable perturbations, and the role of perceptual information, attention and cognitive processes in the control of upright stance.     

Long-range correlation properties in motor timing are individual and task specific

1/f (β) noise represents a specific form of (long-range) correlations in a time series that is pervasive across many sensorimotor variables. Recent studies have shown that the precise properties of the correlations demonstrated by a group of test participants may vary as a function of experimental conditions or factors characterizing the group. Our purpose in the present study was to clarify whether long-range correlations affect sensorimotor performance generally or in a task-specific manner and whether each individual produces characteristic long-range correlations that are reliable across several runs of the same task. We analyzed the series of time intervals produced by 43 participants in two timing tasks: unimanual rhythmic tapping and circle drawing. We found that a participant's 1/f (β) properties in tapping were not related to the 1/f (β) properties in circle drawing. However, within each task, individual differences were reliable, and a Cronbach's alpha of .59 showed a high degree of within-subjects reproducibility of the long-range correlations. Thus, long-range correlations represent a consistent and distinctive characteristic of individuals performing a particular task, rather than a ubiquitous generic property of sensorimotor time series. The implications of these results are discussed from both a theoretical and a methodological perspective.