Learning a co-ordinated Rhythmic movement with task- appropriate co-ordination feedback

Learning a co-ordinated Rhythmic movement with task- appropriate co-ordination feedback

One of the main assumptions made before this experiment was conducted was that when learning to produce a novel movement, people are unable to do it without training. This is explained to be because people are poor at discriminating the perceptual information required to co-ordinate and control the movement, which means people require additional (augmented) feedback to learn the novel task.

· Kelso (1995) stated that people can produce two stable co-ordination patterns without training 0° and 180°. In order to perform other i.e. 90° that pattern has to be learned. #

· Behaviour is said to be organised to the order parameter relative

· 0° and 180° are attractors in this space and in order to learn a new novel co-ordination movement a new attractor has to be created

Perception – action perspective

· This proposes that the phenomena of learning a co – ordinated rhythmic movement emerges from a task dynamic that includes perceptual information as a crucial element (Bingham 2001)

· Learning to produce a novel and unknown movement requires augmented feedback so that the learner knows what they are doing right or wrong

· Visual metronomes and Lissajous figures are used as a way of obtaining feedback; however these methods transform the task so that it no longer is a co-ordination task.

· Both methods show that relative direction is not defined in the feedback display and this alters the process of acquiring a novel co-ordination

· The objective of the task was to describe and test a new method for providing online augmented co-ordination feedback using a neutral colour cue

· Ten participants were split into 2 groups of 5. Group 1 received co-ordination feedback during training, group 2 received no feedback but an equal exposure to the task

· The study concluded that a new method for providing the augmented feedback necessary for learning novel co-ordinated rhythmic movements was developed

· An advantage of this new method is that it doesn’t alter or remove the visual information about the co-ordination task which the other methods do.

Perceptual coupling in rhythmic movement coordination: stable perception leads to stable action

The aim of this study is to test a new technique that allows comparisons to be made between movement measures of between-trail (perceptual) and within-trail (movement) variability within the same perception-action task and person.

Experiment 1

Three groups of 8 students took part. At first participants produced 0° with three practice trails (0:0, 0:180 and 0:90). For the next three trials the cross-modal phase relation was set to 0° (0:0). This was followed by a block of six trials with the crossmodal phase relation set to 90° (0:90). The next six trials set the crossmodal relation to 180° (0:180), followed by three more 0:0 trials. Finally, there were two blocks of four trials in which the instructions were to produce either 180° or 90° visually.

First, they analyzed the MVLW data from the consistent conditions. Pairwise comparisons indicated the main effect of phase condition was due to within-trial stability at 0:0 being higher than the other two conditions, the main effect of frequency was due to stability being higher at 1 Hz. An average 90:90 and 180:180 were not different from each other.

Second, they analyzed the MVLW data from the 0° visual target conditions. Pairwise comparisons showed that the main effect of phase condition was due to within-trial stability at 0:0 being higher than the other two conditions and 0:90 being more stable than 0:180.

A clear relationship existed between within- and between trial stability. The matching scale of the two measures is evidence supporting the hypothesis that the differential movement stability is being caused by the differential perceptual stability.

The main new result is that the 0° visual target stabilized movements that were at a non-0° phase relationship to the dot being tracked.

Experiment 2

The five conditions from experiment 1 where replicated plus two new conditions – 90:0 and 180:0. Pairwise comparisons showed that the 0° visual target conditions were more stable than the non-0° visual target conditions. An ANOVA on the non-0° visual target conditions revealed they did not differ in their stability.

Learning a coordinated rhythmic movement with task appropriate coordination feedback

The aim of this study is to produce a novel coordinated rhythmic movement (90˚ mean relative phase) using coordination feedback during post training. This allows the participant to learn a novel task. This should not alter in any way the perceptual information. It is said that people cannot produce 90˚ novel movements stably without training. They can only produce two stable coordination patterns without training, 0˚ and 180˚. So progression and learning has to occur, in this case coordination feedback is used.

10 participants were split into two groups of five. Group 1 (‘Feedback’) received coordination feedback during training; Group 2 (‘No Feedback’) received no feedback but an equal exposure to the task.

There were two assessment sessions (Baseline and Post-training) and five training sessions. Participants viewed a demo of the target relative phase and then performed five trials. In the five training sessions participants performed ten 20 sec trials with a target mean relative phase of 90˚. There was a computer-controlled dot situated above the person-controlled dot. The participants then used a joystick to move the dot at a specific mean relative phase. For the Feedback group feedback was provided by the colour change of the person-controlled dot from white to green when the participant was moving at 90˚, ± an error bandwidth. In the first session the error bandwidth was set to 40˚. Any performance between 50˚ and 130˚ triggered the colour change. The bandwidth was decreased in each session to 30˚, 20˚, 15˚ and 10˚. This will drive learning as the participant improves after each bandwidth. A colour change was used as the coordinated feedback because it is said that colour has no affect on movement stability. The No Feedback group also did 50 trials, but with no feedback.

A repeated measures ANOVA was used. The results found that participants who received coordination feedback successfully and significantly improved their ability to maintain 90˚ coordination. The No Feedback group showed no improvement at any mean relative phase. Coordination feedback does not alter or remove the visual information (relative direction). Unlike visual metronomes and Lissajous figures which do alter the perceptual information.

People do not tend to suddenly acquire 90˚, as they are unable to move at 90˚ long enough to allow the required perceptual learning. The control group in this experiment received extensive practice at 90˚, but no help identifying when they were moving correctly, so failed to learn this coordination.

Perceptual Learning Immediately Yields New Stable Motor Coordination

This study is focused on the attainment and retention of coordinated rhythmic movements. Specifically, the study assesses the effect of perceptual learning in relation to the demonstration of the movement. Through previous studies, researchers have proved that movements at 0 º and 180 º are stable and can be spontaneously performed without much occurrence of phase variability. Movements at 90 º however, have exhibited an unstable result, concluding that this movement would have to be learned before attainment could be achieved.

The learning of a novel movement based on its stability is not simply attained through physical practise, relying solely on the limbs experience of the movement. Instead, perceptual consequences of the coordinated movement along with transformed feedback results in a non-0 º coordinated movement to be stabilised. Reasons as to why performance at 0 º is easily performed as opposed to other relative phases is due to the essential information being detected more promptly. Therefore, improvement in stability in novel coordination is the participants’ ability to detect essential information through his/her perceptual ability. This study’s prediction is that if the participant is able to improve his/her ability at detecting the essential information then an improvement in stability at 90 º will occur.

12 participants (22-54 years old), half of which were assigned to an experimental group and the other to a controlled group. There were two experimental tasks: two alternative forced choice judgments and coordinated rhythmic movement. Also included were assessment and training sessions. The assessment session included judgment trials and movement trials without feedback; and the training session consisted only of judgement trials with feedback. The controlled group did not participate in the training sessions and received no feedback. There were 21 different trial types regarding judgement trials- 10 different differences x 2 orders and a catch trial. Demonstration was given at the start of the assessment, without feedback throughout session. During the training session participants performed 12 blocks of “choose 90 º” with feedback; these were compared to four other phases. As sessions progressed, discrimination was made harder. If response was correct, they were told; if incorrect, they were given an example of 90 º. Performance during training determined whether participants progressed to a harder training session; however, after four repetitions, they were automatically progressed. During movement trials, force feedback feature was disabled and participants were seated comfortably controlling joystick without actually seeing it. To dots were displayed on the computer screen; top dot was under control of the computer and the bottom dot was controlled by the participant. The computer recorded joystick and computer controlled dots.

Repeated measures ANOVA of the judgement results revealed that participants learned as a result of the training they had received; showing that there was a significant difference for baseline vs. post training at 90 º, however, there was no significant difference when analysing 180 º. A repeated ANOVA was performed on the median proportion of time on task with the tolerance set at 20 º (movement task); two within subject factors were noted: phase levels and session levels. The study found that stability at 90 º improved for the experimental group after training was given. The experimental group showed a main effect of phase as well as an interaction between phase and session while the control group only showed an effect of phase.

This experiment shows that the perception-action couples aid the learning of a coordinated novel movement. This was determined through thorough testing on the experimental and control groups in which the control group exhibited no significant result without perceptual training. The study showed that once perceptual ability was improved, movement stability had been increased, which strongly supports the hypothesis that movement stability is a function of perceptual ability. Perception-action is a system in which there are informational and motor components which contribute towards the overall behaviour of the system.

Learning a coordinated rhythmic movement with task appropriate coordination feedback

The aim of this study is to develop and test a method of providing augmented feedback that could drive learning but not alter the informational content of the task. Ten participants split into two groups of five (one group received feedback and one group didn’t) took part in two assessment sessions and five training sessions. In the training sessions, they performed ten 20-s trials with a target mean relative phase of 90°, for a total of 50 trials. Feedback was provided to the feedback group by changing the colour of the person-controlled dot from white to green when the participant was moving at 90°, ± an error bandwidth. The error bandwidth faded; in the first session, it was set to 40° and was decreased in each session to 30°, 20°, 15°and 10° to drive learning.

A repeated measures ANOVA was carried out on the proportion time on task data (tolerance = 20°) with Session (2levels: Baseline, Post-training) and Phase (3 levels: 0°, 90°and 180°) as within subject factors and Group (2 levels: Feedback, No Feedback) as a between-subject variable. The group who received coordination feedback significantly improved their ability to maintain a 90° coordination. The No Feedback group showed no improvement at any mean relative phase.

This method demonstrated that it is effective at allowing people to acquire a novel coordination, and it does not change the overall perception action task dynamic. This method therefore will be useful in further studies examining the role of perceptual information or in studies that focus on the learning process.