Neuroplasticity: Learning and Changing Behavior, Cognitive Activity

Neural plasticity is the way in which the brain learns new behaviors and changes behaviorally and cognitively based on experience or pathology. There are 10 experience-dependent principles of neural plasticity that need to be understood in order for recovery of both the damaged and intact brain to begin. Neural plasticity decreases how severe a given injury is and gains back loss of function. Part of the brain can compensate for other parts that have been damaged or lost due to pathology, also called using compensatory strategies. The authors describe how learning is the best hope for changing and remodeling the damaged brain. The more we learn new ideas and topics, the more neural connections that will be created. Preston, Brick, and Landi performed a study using ultrasound biofeedback as a treatment option for children with childhood apraxia of speech (CAS) that connects to several of those principles.

Children with CAS have trouble sending messages from their brains to the muscles of their mouths. The messages try to send, but they don’t get through. They may also have some difficulty moving their lips or tongue in the correct position to say certain sounds. These children know exactly what they want to say and don’t have a problem cognitively. The difficulty is within their brain trying to plan and program the muscles. Some deficits associated with this speech sound disorder are the inability to correctly produce speech sounds, stress and intonation, and coarticulatory transitions. The technique used in the article was ultrasound biofeedback. Biofeedback refers to giving individuals feedback about their performance through visual information. The authors used ultrasound in accordance with feedback because it was a better financial option and it also was easier to use with multiple clients.

This study evaluated and determined how efficient ultrasound biofeedback was for children with persistent speech sound errors connected to CAS. Specificity, repetition matters, intensity matters, and transference were some of the neural plasticity principles discussed by Kleim and Jones that apply to this ultrasound biofeedback treatment study. Specificity means that “the nature of the training experience in a certain modality will increase the capacity to acquire behaviors in non-trained modalities”. Repetition matters refer to repeating newly learned behaviors in order to ensure continuing neural change. This is crucial for rehabilitation and is needed for the improvement of the damaged brain. Transference refers to plasticity in one area of the brain influencing and improving functioning in another area not being trained. The last principle that correlates to this treatment article is intensity matters. This means that if therapy and rehabilitation after brain damage include a higher, vigorous simulation, then it will induce long-term powerful change.

Methodology

In the study by Preston et al., there were six children aged nine to 15 with persisting CAS who were recommended to participate through local schools and clinics. To confirm the children’s diagnoses, a licensed speech-language pathologist (SLP) assessed the children by giving them the Goldman-Fristoe Test of Articulation, and acquiring speech samples, and analyzing them. The SLP also ensured that the children scored below an 85% on the sequencing subtest of the Verbal Motor Production Assessment for Children (VMPAC). These children also had to show errors that could be addressed using biofeedback of the tongue. There were eight different sound sequences selected for each child and those were probed throughout the sessions. These sound sequences involved errors that the child made on lingual sounds since those are the sounds that could be seen using ultrasound biofeedback. Eight words connected to those sequences were probed at the end of each session (“eight target words x eight words per sequence = 64 words”). These words varied between monosyllabic and multisyllabic words.

After baseline pretreatment probes, only one target sequence was chosen to be used for treatment, while the other seven were not used. After several sessions, another target sequence was added. Once the child was 80% accurate with a certain sequence on two probes, a new one was added and the previous one was discontinued. If the child was showing no progress on a target sequence after six sessions, the target was discontinued. There was a two-month follow-up after the study ended where the GFTA and a sentence imitation task were given to these students.

Treatment was provided by an SLP or graduate student supervised by the first author. Sessions were twice a week for 60 minutes each and there were 18 of these sessions, which took between 10-16 weeks to finish. Ultrasound biofeedback took about 30 minutes of each session. Using ultrasound biofeedback connects to the specificity neuroplasticity principle. The six children all had specific sounds that they were working on improving and maintaining. This treatment technique was specific to the target sounds and sequences that each child was working on. The first 15 minutes were devoted to one target sequence, then they would do a tabletop activity, then another 15 minutes on a different sequence. There was a high amount of practice trials during each session. In the 24 sessions, there were 228 trials elicited by using this biofeedback approach. 22 out of the 24 sessions elicited at least 150 trials. This relates to the repetition matters neuroplasticity principle. These children were getting repeated performance of this certain skill which helped their brain change and learn new connections. This also allowed the children to maintain their gains outside of the therapy room. This also links to the intensity matters principle. There were 24 sessions that lasted for about 50 minutes each. This was a pretty intensive therapy program which allowed these children to be more likely to make progress and maintain that over time.

Results

The results of this study provided evidence that this treatment approach was very beneficial for this group of children. Each participant showed a significant increase of at least two standard deviations on their treated sound sequence. Since they had high repetitions of practice at an intense rate, their brain was able to change and learn new connections. The biofeedback technique facilitated improvements in speech which resulted in these participants increasing the accuracy of their sound sequences at the word level, while some even showed generalization to the targets that were untreated. This shows how important transference is. Some children were able to produce correct sound sequences that were not being treated with this approach. The ultrasound biofeedback technique focused on particular sounds and sequences and gave them a visual, which allowed the children to master that skill and allowed them to produce really beneficial results, which relates to the specificity principle. This result also relates to repetition matters. Since the children had high rates of practice trials during each session, they were able to make significant gains in improving their speech sound accuracy. They had many opportunities to practice their target sequences. At the two-month follow-up where the GFTA and a sentence imitation task were given to these students, there was a high degree of accuracy for the treated sounds which showed that retention was met.

Discussion

These findings can be a step in the right direction for clinical practice. It’s hard to find a treatment approach that is proven to effectively help older children who have persisting speech sound errors linked to CAS. Not much research has been done regarding treatment options for these children who still have errors that don’t resolve on their own. This article gives great evidence for a beneficial treatment option for this population of children. It provides readers with evidence that ultrasound biofeedback does help children make significant progress in improving their speech sound accuracy.

The article by Kleim and Jones can help future clinicians to discover the various neuroplasticity principles that were embedded into the article by Preston at al. and how they improved the participants’ outcomes. These principles are crucial in helping rehabilitation work the most effectively. The more clinicians know about the brain and how plasticity works, the better the results for rehabilitation will be. In clinical practice, SLPs should make sure to incorporate as many of these principles as they can. Some of the ones that I think are of most importance are repetition matters, intensity matters, and specificity. Therapy that allows for high repetitions at an intense rate will yield the best results. It will allow for the brain to reorganize and induce long-term results.

Although the data in the treatment article revealed rapid improvement, there were some recommendations to be made to future research to better help clinical practice. There were some untreated targets that didn’t show any improvement from this study. In future studies, researchers should apply other strategies and approaches to their target selection to evaluate generalization. The authors also reported that the ultrasound biofeedback approach is most beneficial for improving short sequences and the word-level probes that they obtained may not be reflective of higher-level skills, like sentence and conversational levels.

The majority of intervention was given by graduate students instead of licensed SLPs. There may have been even better results if it was given by experienced clinicians. For future studies, licensed SLPs should give the intervention to see if there is any substantial difference. Lastly, there were some drawbacks for this therapy approach. It was very drill-focused and required high attention from the participants. It also could only target lingual phonemes and could be expensive and difficult to access which could affect how well neural plasticity works. This study was a great start to learning new techniques to help children with persisting speech sound errors.

Conclusion

The ultrasound biofeedback technique provided evidence to be a very reliable form of treatment for children with CAS. They each participated in an intensive therapy program that allowed for high repetitions of target sequences of certain sounds unique to each participant. This study shows how important the principles of neuroplasticity are and how they allow the brain to change and learn new neural connections. Each child showed positive results and improved their accuracy of sound sequences at the word level, while some children are even generalized to the targets that were untreated. This treatment study shows an effective way to help treat persistent speech sound errors in children with CAS and can drive further research to continue coming up with new therapy techniques to help this population of children.