The effect of contextual interference on the learning of adapted sailing for people with spinal cord injury

The aim of this study was to determine the effect of contextual interference on learning of adapted sailing for people with spinal cord injury. Seven participants with traumatic spinal injury were selected to undergo learning in an adapted boat equipped with wind-measuring instrument. A learning program, defined by two conditions, (1) blocked practice and (2) random practice, was applied. In blocked schedule, fixed sequence of two maneuvers consist of tacking on a close-hauled course (45°–55°) and gybing on a broad reaching course (135°–145°). In random schedule, the same maneuvers were carried out randomly. Eight 30-min practice sessions were carried out over a period of 2 weeks, in 3 days per week. Velocity Made Good was analyzed in the familiarization test, pre-test, post-test, and retention test. The learning program was effective in both random and blocked practice conditions on all participants. However, there is an evident variability in the results. This study demonstrates the suitability of applying contextual interference to facilitate the learning of adapted sailing. The variability of the results could be related to the heterogeneity of the participants and suggests the need for further research that can provide information about how restricted mobility affects the learning process.

Neural Substrates of Practice Structure That Support Future Off-Line Learning

Off-line learning is facilitated when motor skills are acquired under a random practice schedule and retention suffers when a similar set of motor skills are practiced under a blocked schedule. The current study identified the neural correlates of a random training schedule while participants learned a set of four-element finger sequences using their nondominant hand during functional magnetic resonance imaging. A go/no go task was used to separately probe brain areas supporting sequence preparation and production. By the end of training, the random practice schedule, relative to the block schedule, recruited a broad premotor–parietal network as well as sensorimotor and subcortical regions during both preparation and production trials, despite equivalent motor performance. Longitudinal analysis demonstrated that preparation-related activity under a random schedule remained stable or increased over time. The blocked schedule showed the opposite pattern. Across individual subjects, successful skill retention was correlated with greater activity at the end of training in the ipsilateral left motor cortex, for both preparation and production. This is consistent with recent evidence that attributes off-line learning to training-related processing within primary motor cortex. These results reflect the importance of an overlooked aspect of motor skill learning. Specifically, how trials are organized during training—with a random schedule—provides an effective basis for the formation of enduring motor memories, through enhanced engagement of core regions involved in the active preparation and implementation of motor programs.

Is the Contextual Interference Effect Generalizable to Computer Games?

The benefits of learning multiple tasks under an unstructured practice schedule have been extensively demonstrated in the laboratory. The purpose of the present study was to test contextual interference effects in a nonlaboratory setting using computer games as tasks. Undergraduate kinesiology and sport management majors ( N=19) played a computer game simulating the events of the winter Olympics. Participants were randomly assigned to either a Blocked or Random practice schedule, practicing 36 trials of three events. Delayed retention and transfer tests were performed after a 48-hr. retention interval. The dependent variable was time to complete an event. During transfer, participants in the Random schedule ( M = 248 sec.) were significantly faster than Blocked ( M = 263 sec.) participants. Results support and extend previous contextual interference findings. Transfer was facilitated for participants who learned the events in a Random practice order. Results are discussed in terms of the influence of task characteristics on learning.

Electrical Tinnitus Suppression: A Double-Blind Crossover Study

A wearable device for transcutaneous electrical tinnitus suppression (ETS) has recently been reported to be effective for relief of tinnitus. Twenty patients with sensorineural hearing loss and tinnitus participated in a double-blind crossover study. Both active devices and internally disconnected placebo devices, supplied by the manufacturer, were used. Reduction in severity of tinnitus was reported by 2 of 20 patients (10%) with the active device and by 4 of 20 (20%) with the placebo device. Fifteen of 20 (75%) had no relief with either device. Those who preferred the placebo device, however, reported only minimal relief, while one of the two who preferred the active device stated it had reduced tinnitus severity by 70% to 80%. This patient was recalled for a series of one-hour test sessions, during which either an active or placebo device was used, according to a random schedule. On each of four on trials, the score for severity of tinnitus for each ear decreased by at least 50% (median = 70%), while in three off trials, the severity of tinnitus was unchanged or decreased by up to 30% (median = 16%). We conclude that the Theraband headset is effective for a small proportion of patients with sensorineural hearing loss and tinnitus.

Recognition of Matching Tasks and Stimulus Novelty as a Function of Unilateral Brain Damage

A 96-trial tachistoscope recognition task was given to 15 left-hemisphere-damaged, 12 right-hemisphere-damaged, and 30 non-brain-damaged subjects. Procedure called for a first stimulus presented for 250 msec. a 1-sec. pause, and a second stimulus for 250 msec. The stimuli were 12 animal drawings used in repeated series according to a random schedule. Six animals were familiar and six were novel. For half of the trials, the two pictures were of different animals. Size and position of the animal picture were controlled. Both reaction time and accuracy were independently scored. Judgments of same and different appear to function as if they are governed by different processes. For the control group, measures of same and different judgments do not correlate highly despite high internal consistency of subtests. Recognition of same becomes impaired with brain damage, but more so if the damage is rightsided. Recognition of different judgments shows considerably less sensitivity to the effects of unilateral brain damage.

Non-Contingent Stimulation: Effects of Stimulus Movement on Infants' Visual and Motor Behavior

The present study was an initial attempt to investigate the effects of non-contingent periodic and aperiodic stimulation on the sensory-motor behavior of 10-wk.-old infants. Results indicated that visual stimulation presented aperiodically (on a random schedule) in contrast to the same stimulation presented periodically (on a fixed time schedule) produced decreased motor activity, heightened visual attention, and a greater number of smiles.

Effects of Random and Response Contingent Noise upon Disfluencies of Normal Speakers

Twenty normal speakers read a passage during a 30-min session divided into Baserate (5 min), Conditioning (15 min), and Extinction (10 min). Each read in Random Condition and Contingent Condition. During Conditioning in Random Condition, subjects received 0.75 sec, 95 dB bursts of white noise according to a random schedule. During Conditioning in Contingent Condition, subjects received a burst of 95 dB white noise each time they were disfluent. Ten subjects (Group RC) read in Random Condition on one day and in Contingent Condition on a subsequent day. The other 10 subjects read in the opposite order of conditions on the two days. Results indicated that the effects of random and contingent noise were influenced by the order of conditions. Random aversive stimuli caused increases in disfluency for subjects in both groups. Response contingent aversive stimuli caused a decrement in disfluency for subjects in Group CR, but not for subjects in Group RC. Analysis of poststimulus disfluency indicated that random aversive stimuli caused disorganization of the speech of subjects in Group RC.