On-line versus off-line control of rapid aiming movements

Recent studies have shown the importance of visual feedback during the rapid initial phase of aiming movements for the control of direction (e.g., Bard, Paillard, Fleury, Hay, & Larue, 1990; Blouin, Teasdale, Bard, & Fleury, in press; Teasdale, Blouin, Bard, & Fleury, 1991). In most of these studies, visual feedback conditions were presented in blocked sessions. Consequently, higher-order processes (e.g., feedforward and/or learning processes), along with on-line processing of visual feedback, might have contributed to the better accuracy found when subjects had visual feedback of only the initial portion of the movements (compared with movements without visual feedback). To test this possibility, we studied subjects' performance of rapid arm movements under different types of presentation (random, precued, and blocked) of the visual feedback conditions of the trajectory (no vision, initial portion only, and vision of the entire trajectory). Directional errors were larger in the no-vision condition than in both conditions with visual feedback. There were no differences among the presentation conditions, suggesting that on-line processing of visual information contributed to the control of the arm movements.     

Afferent Information for Motor Control: The Role of Visual Information in Different Portions of the Movement

The question addressed in the present study was whether subjects (N = 24) can use visual information about their hand, in the first half of an aiming movement, to ensure optimal directional accuracy of their aiming movements. Four groups of subjects practiced an aiming task in either a complete vision condition, a no-vision condition, or in a condition in which their hand was visible for the first half [initial vision condition (IV)] or the second half of the movement [final vision condition (FV)]. Following 240 trials of acquisition, all subjects were submitted to a transfer test that consisted of 40 trials performed in a no-vision condition. The results indicated that seeing the hand early in movement did not help subjects to optimize either directional or amplitude accuracy. On the other hand, when subjects viewed their hand closer to the target, movements resulted that were as accurate as those performed under a complete vision condition. In transfer, withdrawing vision did not cause any increase in aiming error for the IV or the no-vision conditions. These results replicated those of Carlton (1981) and extended those of Bard and colleagues (Bard, Hay, & Fleury, 1985) in that they indicated that the kinetic visual channel hypothesized by Paillard (1980; Paillard & Amblard, 1985) appeared to be inoperative beyond 40deg of visual angle.     

Influence of feedback modality on sensorimotor adaptation: contribution of visual, kinesthetic, and verbal cues

In 4 studies, the authors tested the contributions of visual, kinesthetic, and verbal knowledge of results to the adaptive control of reaching movements toward visual targets. The same apparatus was used in all experiments, but the procedures differed in the sensory modality of the feedback that participants (N s = 5, 5, 6, and 6, respectively, in Experiments 1, 2, 3, and 4) received about their performances. Using biased visual, proprioceptive, or verbal feedback, the authors introduced a 5 degrees shift in the visuomanual relationship. Results showed no significant difference in the final amount of adaptation to the mismatch: On average, participants adapted to 79% of the perturbation. That finding is consistent with the view that adaptation is a multisensory, highly flexible process whose efficiency does not depend on the sensory channel conveying the error signal.     

Development of interactions between sensorimotor representations in school-aged children

Reliable sensory-motor integration is a pre-requisite for optimal movement control; the functionality of this integration changes during development. Previous research has shown that motor performance of school-age children is characterized by higher variability, particularly under conditions where vision is not available, and movement planning and control is largely based on kinesthetic input. The purpose of the current study was to determine the characteristics of how kinesthetic-motor internal representations interact with visuo-motor representations during development. To this end, we induced a visuo-motor adaptation in 59 children, ranging from 5 to 12 years of age, as well as in a group of adults, and measured initial directional error (IDE) and endpoint error (EPE) during a subsequent condition where visual feedback was not available, and participants had to rely on kinesthetic input. Our results show that older children (age range 9–12 years) de-adapted significantly more than younger children (age range 5–8 years) over the course of 36 trials in the absence of vision, suggesting that the kinesthetic-motor internal representation in the older children was utilized more efficiently to guide hand movements, and was comparable to the performance of the adults.     

Sleep problems of parents of typically developing children and parents of children with autism

Few researchers have investigated the relation of children's sleep problems to their parents' sleep problems. Children with autism have been reported to evidence greater sleep problems than do typically developing children (C. D. Hoffman, D. P. Sweeney, J. E. Gilliam, & M. C. Lopez-Wagner, 2006; P. G. William, L. L. Sears, & A. Allard, 2004). In the present study, parents (N = 106) of children independently diagnosed with autism (4-16 years of age; M= 8.20 years, SD = 2.69 years) reported greater sleep problems for themselves than did parents (N = 168) of typically developing children (4-15 years of age; M = 8.62 years, SD = 3.28 years). Children's sleep problems were related to parents' sleep problems for both groups; in the autism group, children's level of symptomatology was not related to their parents' sleep. The authors suggest areas for further research on the sleep problems of children and their parents, the potential interaction of these problems with children's symptomatic behavior, and the relations of these factors to child, parent, and family functioning.     

The Children's Attributional Style Interview: Developmental Tests of Cognitive Diathesis-Stress Theories of Depression

This paper presents an initial assessment of the Children's Attributional Style Interview (CASI), a newly designed measure for assessing attributional style in young children (age 5 and up). The CASI was used to conduct prospective tests of the reformulated helplessness (L. Y. Abramson, M. Seligman, & J. Teasdale, 1978) and the integrated hopelessness/self-esteem (G. I. Metalsky, T. E. Joiner, Jr., T. S. Hardin, & L. Y. Abramson, 1993) theories of depression in a sample of 147 5–10-year-old children. For comparison, the same tests were also conducted with the Children's Attributional Style Questionnaire-Revised (CASQ-R; N. J. Kaslow & S. Nolen-Hoeksema, 1991), a commonly used measure for assessing attributional style in older children (age 8 and up). The CASI evidenced support of the reformulated helplessness theory and partial support of the integrated hopelessness/self-esteem theory. The CASI also demonstrated good internal consistency. Thus, our findings provide initial support for the CASI as a methodologically sound measure of attributional style for children as young as 5 years old. Although preliminary, our findings also suggest possible developmental differences in how attributional style interacts with self-esteem and negative life stress. The CASI should prove to be a useful tool in furthering the understanding of the origins and development of attributional style in childhood, as well as its contribution to the understanding of the development and prevention of depressive symptomatology in children.     

Developmental study of short-term memory characteristics for kinesthetic movement information

The present experiment was designed to examine age-related characteristics of short-term retention of kinesthetic movement information. 20 children from each age group (6, 8, 10 yr.) were tested for recall of kinesthetic end-location. The results indicate that 6- and 8-yr.-old children became less accurate and more variable in recall performance following a delay interval. However, 10-yr.-old children were capable of maintaining performance accuracy during a delay interval.     

Short-term limb immobilization affects motor performance

C. Ghez, J. Gordon, and M. R Ghilardi (1995; J. Gordon, M. R Ghilardi, & C. Ghez, 1995; R. L. Sainburg, M. R Ghilardi, H. Poizner, & C. Ghez, 1995) have found that proprio-ceptive deafferentation impairs feedforward and feedback mechanisms that control reaching movements. In the present study, the authors found immobilization-induced changes in limb kinematics, including joint motion, in 32 healthy participants who performed out-and-back movements before and after 0, 6, or 12 hr of immobilization of the left arm. Control participants did not undergo the arm immobilization procedure. Immobilization for 12 hr, but not 6 hr, caused trajectories with increased hand-path areas and altered interjoint coordination. The abnormalities were smaller in amplitude but similar in quality to those reported in deafferented patients (R. L. Sainburg et al.). In addition, movement onset point significantly drifted after immobilization. Thus, short-term limb disuse can affect interjoint coordination by acting on feedforward mechanisms. These behavioral alterations are potentially related to cortical plastic changes.     

Impaired re-weighting of sensory feedback for maintenance of postural control in children with developmental coordination disorder

To further the understanding of postural control impairments seen in children with developmental coordination disorder (DCD) and the effect of these impairments on motor performance in these children, 30 children with and without DCD (mean age=9 years, 7 months +/- 1 year, 10 months) were administered the Movement Assessment Battery for Children (M-ABC), Wechsler Abbreviated Scale of Intelligence and the Sensory Organization Test. Analyses of covariance revealed that children with DCD had greater difficulty maintaining postural control when visual and somatosensory feedback were compromised in sensory conflict environments (p=.031). Group differences in postural control were independent of age. Additionally, no correlation was seen between motor performance on the M-ABC and postural control measures for the Sensory Organization Test. Our results demonstrate that impaired ability to utilize vestibular feedback while re-weighting somatosensory and visual feedback for orientation may be responsible, in part, for the postural control impairments observed in some children with DCD.     

Gaze behaviors of goaltenders under spatial-temporal constraints

It is still not known what underlies successful performance in goaltending. Some studies have reported that advanced cues from the shooter's body (hip, kicking leg or support leg) are most important (Savelsbergh, G. J. P., Williams, A. M., Van der Kamp, J., & Ward, P. (2002). Visual search, anticipation and expertise in soccer goalkeepers. Journal of Sports Sciences, 20, 279-287; Savelsbergh, G. J. P., Williams, A. M., Van der Kamp, J., & Ward, P. (2005). Anticipation and visual search behaviour in expert soccer goalkeepers. Ergonomics, 48, 1686-1697; Williams, A. M., & Burwitz, L. (1993). Advanced cue utilization in soccer. In T. Reilly, J. Clarys, & A. Stibbe (Eds.), Science and football II (pp. 239-243). London, England: E&FN Spon), while others have found that the early tracking of the object prior to and during flight is most critical (Bard, C., & Fleury, M. (1981). Considering eye movement as a predictor of attainment. In: I. M. Cockerill, & W. M. MacGillvary (Eds.), Vision and Sport (pp. 28-41). Cheltenham, England: Stanley Thornes (Publishers) Ltd.). These results are similar to those found in a number of interceptive timing studies (Land, M. F., & McLeod, P. (2000). From eye movements to actions: How batsmen hit the ball. Nature Neuroscience, 3, 1340-1345; Ripoll and Fleurance, 1988; Vickers, J. N., & Adolphe, R. M. (1997). Gaze behaviour during a ball tracking and aiming skill. International Journal of Sports Vision, 4, 18-27). The coupled gaze and motor behavior of elite goaltenders were determined while responding to wrist shots taken from 5 m and 10 m on ice. The results showed that the goalies faced shots that were significantly different in phase durations due to distance (5 versus 10 m), but this was not a factor in making saves. Instead, the ability to stop the puck was dependent on the location, onset and duration of the final fixation/tracking gaze (or quiet eye) prior to initiating the saving action. The relative onset of quiet eye was significantly (p<.001) earlier (8.6%) and the duration was longer on saves (M=80.5%; 952.3 ms) compared to goals (onset 18.86%; M=70.1%, 826.1 ms). The quiet eye was located on the puck/stick during the preparation and execution of the shot in 70.53% of all trials, or on the ice in front of the release point of the puck (25.68%) and rarely on the body of the shooter (2.1%). The results are discussed within the context of current research on goaltending with specific emphasis on the timing of critical cues and the effect of tasks constraints.     

Timing and accuracy of visually directed movements in children: control of direction and amplitude components

The reaction times (RTs), movement times (MTs), and final accuracy of hand movements directed towards visual goals were measured in 6-, 8-, and 10-year-old children, using tasks in which direction and amplitude components of movement were distinctly required. The tasks were performed with and without visual feedback of the limb. RTs decreased with age, and were shorter in directional than in amplitude task, in all ages. MTs were the longest at age 8 in both tasks, equally short at ages 6 and 10 in the directional task, the shortest at age 10, and intermediate at age 6, when amplitude had to be regulated. In the amplitude task, the target distance generally affected MTs under both visual conditions, but to a lower degree at age 10 than in the two younger groups. Movement accuracy, which was in all cases higher with visual feedback, showed different developmental trends among the two spatial components: directional accuracy was not different among the three groups of age, whereas amplitude accuracy showed a nonmonotonic development in the nonvisual condition, with an increase between age 6 and age 10, and the lowest level at age 8. In the visual condition, amplitude accuracy did not change with age. The specification of direction seems therefore to predominantly load the preparatory stage of the response. Amplitude specification seems to be more dependent on on-going regulations and to undergo a longer and more complex development, with a critical period around age 8 when a greater propensity for a feedback-based control appears on the two components. With increasing age, amplitude tends to be specific to a greater extent by a feedforward process.     

Effects of field-articulation and feedback on perception of intermediate visual-kinesthetic position.

High and low field-articulators were compared on the accuracy with which they could adjust a rod to intermediate visual-kinesthetic positions while blindfolded, under four sensory-feedback conditions. Independent groups of 10 Ss were given auditory, visual, kinesthetic, or no sensory feedback for 16 trials and then tested on 8 trials without sensory feedback. High field-articulators were significantly more accurate on the feedback trials for all sensory-feedback conditions but not in terms of mean absolute error. The mean constant error on the test trials was significantly lower for the high field-articulators on all feedback conditions except for visual feedback where the low field-articulator had a lower constant error. Both the high and low field-articulators became more accurate and learned more in judging visual-kinesthetic position when auditory feedback was given. Low field-articulators showed significant improvement in accuracy with kinesthetic feedback. The results supported the hypothesis that intermediate directions can be learned and supported previous perceptual research.     

Mechanisms that underlie coordination in children with developmental coordination disorder

The authors examined potential mechanisms underlying motor coordination in children with developmental coordination disorder (DCD). Because children with DCD experience difficulty processing visual, auditory, and vibrotactile information, the authors explored patterns of choice reaction time (RT) in young (6-7 years) and older (9-10 years) children with and without DCD by using a compatibility-incompatibility paradigm and different sensory modalities. Young children responded more slowly than older children to visual, auditory, and vibrotactile stimuli. Children with DCD took longer than typical children to process visual and vibrotactile stimuli under more complex stimulus-response mappings. Young children with DCD responded more slowly than typical children to visual and vibrotactile information under incompatible conditions. Children with DCD responded faster than unaffected children to auditory stimuli. The results suggest that there is a developmental nature in the processing of visual and auditory input and imply that the vibrotactile sensory modality may be key to the motor coordination difficulties of children with DCD.     

The effect of placement instability on adopted children's inhibitory control abilities and oppositional behavior

This study assessed relations among placement instability, inhibitory control, and caregiver-rated child behavior. The sample included 33 adopted children who had experienced placement instability, 42 adopted children who had experienced 1 stable placement, and 27 children never placed in foster care. Five- and 6-year-old children completed the day-night task, which requires children to inhibit a prepotent response, and a control task that presents similar memory demands but does not require inhibition (C. L. Gerstadt, Y. J. Hong, & A. Diamond, 1994). Adopted children who had experienced placement instability performed worse on the inhibition task than did both other groups of children, when the authors controlled for age, verbal intelligence (as measured with the Wechsler Preschool and Primary Scale of Intelligence--Revised; D. Wechsler, 1989; or the Peabody Picture Vocabulary Test--Third Edition; L. M. Dunn & L. M. Dunn, 1997), and control task performance (p<.01). Children who had experienced placement instability were also rated on the Child Behavior Checklist as more oppositional than other children (p<.01; T. M. Achenbach & L. A. Rescorla, 2000). Inhibitory control did not mediate the association between placement instability and oppositional behavior (p>.05). These results suggest that placement instability may adversely affect the social-emotional development of adopted children.     

Imagery ability and the acquisition and retention of movements

In this study, we examined the relationship between imagery ability, as measured by the Movement Imagery Questionnaire (MIQ), and the acquisition, retention, and reacquisition of movements. Based on their MIQ scores, 10 subjects were selected for the following imagery groups: high visual/high kinesthetic (HH), high visual/low kinesthetic (HL), and low visual/low kinesthetic (LL). The subjects learned four movements to a criterion level. Before each trial, subjects kinesthetically imaged the movement about to be produced. Following each acquisition trial, subjects were provided visual feedback. The acquisition phase was followed by a 2-day retention interval, a retention test consisting of three trials on each movement (no feedback provided), and a reacquisition phase. The HH group acquired the movements in the least number of trials, the LL group required the greatest number of trials, and the HL group required an intermediate number of trials. The data for the reacquisition phase showed the same trend. There was only weak evidence for a relationship between imagery ability and the retention of the movements. These findings support the position that high imagery ability facilitates the acquisition, but probably not the short term retention, of movements.     

Visual and Kinesthetic Components of Pursuit-Tracking Performance

Ss (N=75) were trained on a pursuit rotor for 10 trials with ambient illumination from a strobe light flashing at frequencies of either 2, 5, 10, 15, or 20/sec. A transfer trial followed, with a strobe flashing frequency of 10/sec for all Ss. Results supported hypotheses derived from Adams’ (1971) closed-loop theory of motor learning that (a) performance would improve during training as a function of amount of visual feedback available, and that (b) if after training visual feedback was reduced, performance would be maintained to the extent that reliance upon kinesthetic feedback had been learned as an alternate compensatory feedback loop.     

Age differences in noise and variability of isometric force production.

This study examined whether age-related improvements observed in the motor performance of children result from a reduction of noise in the output of the sensori-motor system. Children ages 6, 8, and 10 years and young adults (N = 48, 12 per group) performed continuous, constant isometric force contractions with the index finger at four different force levels with and without visual feedback. The results revealed that: (a) performance improved with increases in age, (b) the force output signal exhibited increased irregularity and a more broadband frequency profile with increases in age under conditions with feedback, and (c) there were no age differences in the irregularity of the force signal and smaller age differences in the frequency profiles under conditions without feedback. It is proposed that the age-related enhancements in performance throughout childhood are primarily due to a more appropriate mapping of the organization of the sensori-motor system to the task constraints rather than to reduction of system noise.     

Re: Views

Interviewing Strategies for Helpers: A Guide to Assessment, Treatment, and Evaluation: William H. Cormier and L. Sherilyn Cormier ; Barron's Guide to the Two-Year Colleges. Volume II: Occupational Program Selector Woodbury, N.Y.: Rational Emotive Therapy in Practice: James A. Bard ; Champaign, Ill: Getting into Medical School: The Premedical Student's Guidebook (4th ed.); Sanford J. Brown; Woodbury, N.Y.: Handbook for Job Placement for Mentally Retarded Workers: Training, Opportunities, and Career Areas (3rd ed.); Angeline M. Jacobs , Judith K. Larson , and Claudette A. Smith; Palo Alto, Calif.: Counseling the Elderly: For Professional Helpers Who Work with the Aged; Edited by Garry L. Landreth and Robert C. Berg; Assertion Training: A Facilitator's Guide; Colleen Kelley; La Jolla, Calif.:     

Susceptibility to the flash-beep illusion is increased in children compared to adults

Audio-visual integration was studied in children aged 8-17 (N = 30) and adults (N = 22) using the 'flash-beep illusion' paradigm, where the presentation of two beeps causes a single flash to be perceived as two flashes (fission illusion), and a single beep causes two flashes to be perceived as one flash (fusion illusion). Children reported significantly more fission illusions than adults, indicating that auditory and visual information was integrated more often, and less selectively, than in adults. Within either group, illusion reports did not correlate with either age or motor coordination measures. The current results show that the form of multisensory integration indexed by the illusion is slow to mature in normally developing children.