Declarative Learning Mechanisms Support Declarative but Not Probabilistic Feedback-Based Learning in Children with Developmental Language Disorder (DLD).

Declarative and probabilistic feedback-based learning was evaluated in 8-12-year-old school-age children with developmental language disorder (DLD; n = 14) and age-matched children with typical development (TD; n = 15). Children performed a visual two-choice word-learning task and a visual probabilistic classification task while their electroencephalogram (EEG) was recorded non-invasively from the scalp. Behavioral measures of accuracy and response to feedback, and electrophysiological responses to feedback were collected and compared between the two groups. While behavioral data indicated poorer performance by children with DLD in both learning paradigms, and similar response patterns to positive and negative feedback, electrophysiological data highlighted processing patterns in the DLD group that differed by task. More specifically, in this group, feedback processing in the context of declarative learning, which is known to be dominated by the medial temporal lobe (MTL), was associated with enhanced N170, an event-related brain potential (ERP) associated with MTL activation. The N170 amplitude was found to be correlated with declarative task performance in the DLD group. During probabilistic learning, known to be governed by the striatal-based learning system, the feedback-related negativity (FRN) ERP, which is the product of the cortico-striatal circuit dominated feedback processing. Within the context of probabilistic learning, enhanced N170 was associated with poor learning in the TD group, suggesting that MTL activation during probabilistic learning disrupts learning. These results are interpreted within the context of a proposed feedback parity hypothesis suggesting that in children with DLD, the system that dominates learning (i.e., MTL during declarative learning and the striatum during probabilistic learning) dominates and supports feedback processing.

With or without Feedback?-How the Presence of Feedback Affects Processing in Children with Developmental Language Disorder.

Language acquisition depends on the ability to process and learn probabilistic information, often through the integration of performance feedback. Children with developmental language disorder (DLD) have demonstrated weaknesses in both probabilistic learning and feedback processing, but the individual effects of each skill are poorly understood in this population. This study examined school-aged children with DLD (n = 29) and age- and gender-matched children with typical development (TD; n = 44) on a visual probabilistic classification learning task presented with and without feedback. In the feedback-based version of the task, children received performance feedback on a trial-by-trial basis during the training phase of the task. In the feedback-free version, children responded after seeing the correct choice marked with a green border and were not presented with feedback. Children with TD achieved higher accuracy than children with DLD following feedback-based training, while the two groups achieved similar levels of accuracy following feedback-free training. Analyses of event-related potentials (ERPs) provided insight into stimulus encoding processes. The feedback-free task was dominated by a frontal slow wave (FSW) and a late parietal component (LPC) which were not different between the two groups. The feedback-based task was dominated by a parietal slow wave (PSW) and an LPC, both of which were found to be larger in the TD than in the DLD group. In combination, results suggest that engagement with feedback boosts learning in children with TD, but not in children with DLD. When the need to process feedback is eliminated, children with DLD demonstrate behavioral and neurophysiological responses similar to their peers with TD.

Between Shifting and Feedback Processing in the Wisconsin Card Sorting Test in Children with Developmental Language Disorder.

Children with developmental language disorder (DLD) demonstrate deficits in executive functioning; however, the specific components of executive functioning that are affected in this population are not well understood. This study evaluated set shifting and feedback processing in a Wisconsin Card Sorting Test (WCST) performed by 24 children with and without DLD. The behavioral results revealed poorer performance by the DLD group in measures of accuracy, proportion of correct rule shifts, perseverative errors on shift trials, and proportion of effective responses to feedback. Electrophysiological measures (event-related potentials, or ERPs) indicated different patterns of response to negative feedback that signaled the need for rule shifting, with the DLD group showing a trend toward processing shift cues as negative feedback. Group differences were found in the processing of the first and last positive feedback, with overall stronger responses to positive feedback by children with DLD. However, both groups showed a similar pattern of diminished attention to positive feedback when rule learning was established. Taken together, children with DLD demonstrated the inefficient processing of negative feedback in the context of rule-shifting and difficulty in establishing and maintaining a rule.

The contribution of theta and delta to feedback processing in children with developmental language disorder.

PURPOSE: The study aimed at evaluating feedback processing at the electrophysiological level and its relation to learning in children with developmental language disorder (DLD) to further advance our understanding of the underlying neural mechanisms of feedback-based learning in children with this disorder. METHOD: A feedback-based probabilistic learning task required children to classify novel cartoon animals into two categories that differ on five binary features, the probabilistic combination of which determined classification. The learning outcomes' variance in relation to time- and time-frequency measures of feedback processing were examined and compared between 20 children with developmental language disorder and 25 age-matched children with typical language development. RESULTS: Children with developmental language disorder (DLD) performed poorer on the task when compared with their age-matched peers with typical language development (TD). The electrophysiological data in the time domain indicated no differences in the processing of positive and negative feedback among children with DLD. However, the time-frequency analysis revealed a strong theta activity in response to negative feedback in this group, suggesting an initial distinction between positive and negative feedback that was not captured by the ERP data. In the TD group, delta activity played a major role in shaping the FRN and P3a and was found to predict test performance. Delta did not contribute to the FRN and P3a in the DLD group. Additionally, theta and delta activities were not associated with the learning outcomes of children with DLD. CONCLUSION: Theta activity, which is associated with the initial processing of feedback at the level of the anterior cingulate cortex, was detected in children with developmental language disorder (DLD) but was not associated with their learning outcomes. Delta activity, which is assumed to be generated by the striatum and to be linked to elaborate processing of outcomes and adjustment of future actions, contributed to processing and learning outcomes of children with typical language development but not of children with DLD. The results provide evidence for atypical striatum-based feedback processing in children with DLD.

Retrograde peri-implantitis: incidence and possible co-existing factors: a retrospective analysis.

OBJECTIVES: To evaluate the incidence of retrograde peri-implantitis (RPI) generally and the incidence of RPI with an endodontic-treated adjacent tooth and/or a periapical radiolucency. METHOD: The retrospective case-control study included the follow-up periapical images of single dental implants. Two calibrated graduate endodontic residents evaluated simultaneously the presence of RPI and the adjacent teeth status (a previous root canal treatment (RCT) and the periapical status). RESULTS: Six hundred and eleven dental implants were included in this study. Twenty-three implants with RPI were detected (the incidence of RPI was 3.7%). Thirty-one adjacent teeth to the implants with RPI were recognized. Out of them, seven teeth had a previous RCT and periapical radiolucency or no RCT and periapical radiolucency. The odds ratios for RPI in an implant with periapical radiolucency or with RCT at the adjacent tooth are 6.67 (95% CI 2.7-16.5), P < 0.05; and 0.11 (95% CI 0.007-1.9), P > 0.05 respectively. CONCLUSIONS: Based on periapical radiographs, the RPI incidence was 3.7% in the present study. The incidence of RPI increased in cases with adjacent teeth that had periapical radiolucency. Previous RCT in teeth adjacent to implants without apical radiolucency is not correlated with RPI.

Feedback Processing During Probabilistic Learning in Children With Developmental Language Disorder: An Event-Related Potential Study.

PURPOSE: The purpose of this study was to examine feedback processing within the context of probabilistic learning in children with and without developmental language disorder (DLD). METHOD: The probabilistic category learning task required 28 children ages 8-13 years old to classify novel cartoon animals that differed in five binary features into one of two categories. Performance feedback guided incremental learning of the stimuli classifications. Feedback processing was compared between children with DLD and age-matched children with typical development (TD) by measuring the magnitude of feedback-related event-related potentials. Additionally, the likelihood of each group to repeat a classification of a stimulus following positive feedback ("stay" behavior) and change a classification following negative feedback ("switch" behavior) served as a measure of the consequence of feedback processing. RESULTS: Children with DLD achieved lower classification accuracy on all learning outcomes compared to their peers with TD. Children with DLD were less likely than those with TD to demonstrate "stay" behavior or to repeat a correct response following positive feedback. "Switch" behavior or changing an incorrect response following negative feedback was found to be at chance level in both groups. Electrophysiological data indicated that children with DLD had a smaller feedback-related negativity effect (i.e., smaller differential processing of positive and negative feedback) when compared to children with TD. Although no differences were found between the two groups in the amplitude of the P3a, strong positive correlations were found between "stay/switch" behavior and the P3a for children in the TD group only. CONCLUSIONS: Children with DLD do not appear to benefit from incremental corrective feedback to the same extent as their peers with TD. Processing differences are captured in the initial stages of feedback evaluation and in translating information carried by the feedback to inform future actions.

An Implicit-Explicit Framework for Intervention Methods in Developmental Language Disorder.

PURPOSE: The growing interest in framing intervention approaches as either implicit or explicit calls for a discussion of what makes intervention approaches engage each of these learning systems, with the goal of achieving a shared framework. This tutorial presents evidence for the interaction between implicit and explicit learning systems, and it highlights the intervention characteristics that promote implicit or explicit learning as well as outcome measures that tap into implicit or explicit knowledge. This framework is then applied to eight common intervention approaches and notable combinations of approaches to unpack their differential engagement of implicit and explicit learning. CONCLUSIONS: Many intervention characteristics (e.g., instructions, elicitation techniques, feedback) can be manipulated to move an intervention along the implicit-explicit continuum. Given the bias for using explicit learning strategies that develops throughout childhood and into adulthood, clinicians should be aware that most interventions (even those that promote implicit learning) will engage the explicit learning system. However, increased awareness of the implicit and explicit learning systems and their cognitive demands will allow clinicians to choose the most appropriate intervention for the target behavior.

A retrospective study of oral pathoses in Israeli military divers and non-divers: 2011-2020.

BACKGROUND/AIM: Self-contained underwater breathing apparatus (SCUBA) diving has grown tremendously as a recreational sport over the past decade. The pain divers experience due to barometric changes is referred to as barodontalgia, and it is known to cause various oral pathoses. Furthermore, divers suffer more frequently from temporomandibular disorders than non-divers. The aim of the study was to characterize oral pathoses between military divers and military non-divers. MATERIAL AND METHODS: Data from the dental files of healthy Israel Defense Forces (IDF) soldiers aged 18-40 years were collected retrospectively for the years 2011-2020. The data for subjects exposed to diving were compared to commando and special forces soldiers. RESULTS: The study population was composed of 6398 soldiers, which included 1036 divers and 5362 non-divers. All participants were male, with a median age of 22 years (mean = 22.1 years). Overall, higher rates of faulty dental restorations were seen among divers than non-divers (9.3% vs. 6.7% p = .006). Temporomandibular disorders were more prevalent among divers, specifically Disc Displacement Without Reduction (DDWOR) (0.4% vs. 0.1% p = .003). While dental fractures showed no significant difference between divers and non-divers (3.8% vs. 3.5% p = 0.8), other oral injuries were nine times more prevalent among divers versus non-divers. CONCLUSION: Military divers are, overall, at a higher risk of oral pathoses than non-divers. This may be related to the characteristics and intensity of their military service.

Artificial Grammar Learning in Children With Developmental Language Disorder.

PURPOSE: The purpose of the study was to evaluate implicit learning in children with developmental language disorder (DLD) by employing a visual artificial grammar learning task. METHOD: Thirteen children with DLD and 24 children with typical language development between the ages of 8 and 12 years completed a visual artificial grammar learning task. During the training phase of the task, participants were presented with strings of shapes that followed the underlying structure of a finite grammar. During the testing phase, participants were asked to judge whether new strings were grammatical or nongrammatical. Grammatical judgment of new strings served to measure generalization of the underlying grammatical structure. Endorsement based on chunk strength, or similarity to training exemplars, served to evaluate the extent to which children relied on surface features to guide their task performance. RESULTS: As a group, children with typical development performed better on the artificial grammar learning task, compared with children with DLD, and accepted more grammatical strings regardless of their similarity to training exemplars. Task performance in both groups was not affected by surface features. Performance of children with DLD whose test accuracy exceeded the learning threshold of 0.5 was consistent with a generalization of the underlying grammatical structure that was unaffected by surface features. CONCLUSIONS: The study found group differences in learning outcomes between children with and without DLD. Consistent with previous reports, children with typical development correctly endorsed more grammatical strings than children with DLD, suggesting a better acquisition of the grammatical structure. However, there was no evidence to suggest that children in the DLD group (learners and nonlearners) relied on surface features (i.e., familiarity to training exemplars) in their grammatical judgment. These results refute our hypothesis that children in the DLD group would show judgment based on familiarity.

Strategy Development and Feedback Processing During Complex Category Learning.

In this study, 38 young adults participated in a probabilistic A/B prototype category learning task under observational and feedback-based conditions. The study compared learning success (testing accuracy) and strategy use (multi-cue vs. single feature vs. random pattern) between training conditions. The feedback-related negativity (FRN) and P3a event related potentials were measured to explore the relationships between feedback processing and strategy use under a probabilistic paradigm. A greater number of participants were found to utilize an optimal, multi-cue strategy following feedback-based training than observational training, adding to the body of research suggesting that feedback can influence learning approach. There was a significant interaction between training phase and strategy on FRN amplitude. Specifically, participants who used a strategy in which category membership was determined by a single feature (single feature strategy) exhibited a significant decrease in FRN amplitude from early training to late training, perhaps due to reduced utilization of feedback or reduced prediction error. There were no significant main or interaction effects between valence, training phase, or strategy on P3a amplitude. Findings are consistent with prior research suggesting that learners vary in their approach to learning and that training method influences learning. Findings also suggest that measures of feedback processing during probabilistic category learning may reflect changes in feedback utilization and may further illuminate differences among individual learners.

Learning With and Without Feedback in Children With Developmental Language Disorder.

Purpose Intervention provided to school-age children with developmental language disorder often relies on the provision of performance feedback, yet it is unclear whether children with this disorder benefit from feedback-based learning. The study evaluates the effect of performance feedback on learning in children with developmental language disorder. Method Thirteen 8- to 12-year-old children with developmental language disorder and 14 age- and gender-matched children with typical language development completed two learning tasks whose objective was to pair nonword novel names with novel objects. The two tasks differed in the presence of performance feedback to guide learning. Learning outcomes on immediate and follow-up tests were compared between the feedback-based and feedback-free tasks. Additionally, an electrophysiological marker of feedback processing was compared between children with and without developmental language disorder. Results Children with developmental language disorder demonstrated poorer learning outcomes on both tasks when compared with their peers, but both groups achieved better accuracy on the feedback-free task when compared with the feedback-based task. Within the feedback-based task, children were more likely to repeat a correct response than to change it after positive feedback but were as likely to repeat an error as they were to correct it after receiving negative feedback. While children with typical language elicited a feedback-related negativity with greater amplitude to negative feedback, this event-related potential had no amplitude differences between positive and negative feedback in children with developmental language disorder. Conclusions Findings indicate that 8- to 12-year-old children benefit more from a feedback-free learning environment and that negative feedback is not as effective as positive feedback in facilitating learning in children. The behavioral and electrophysiological data provide evidence that feedback processing is impaired in children with developmental language disorders. Future research should evaluate feedback-based learning in children with this disorder using other learning paradigms.

Electrophysiological Examination of Feedback-Based Learning in 8-11-Year-Old Children.

The study aimed at evaluating the extent to which the feedback related negativity (FRN), an ERP component associated with feedback processing, is related to learning in school-age children. Eighty typically developing children between the ages of 8 and 11 years completed a declarative learning task while their EEG was recorded. The study evaluated the predictive value of the FRN on learning retention as measured by accuracy on a follow-up test a day after the session. The FRN elicited by positive feedback was found to be predictive of learning retention in children. The relationship between the FRN and learning was moderated by age. The P3a was also found to be associated with learning, such that larger P3a to negative feedback was associated with better learning retention in children.

The Effect of Feedback on Attention Allocation in Category Learning: An Eye Tracking Study.

It has been suggested that category learning involves changes in attention allocation based on the relevance of input to the classification. Using eye-gaze measures, Rehder and Hoffman studied changes in attention allocation during category learning in a 5-4 category structure paradigm with four features of varying diagnosticity levels. In this paradigm, participants are tasked with classifying creatures into two groups through trial and error guided by feedback. While learners' eye-gaze patterns have been studied as a function of feature diagnosticity levels throughout the learning process, they have not been evaluated in relation to performance and feedback. The present study borrowed and modified Rehder and Hoffman's category paradigm and evaluated eye-gaze behavior as a function of the diagnosticity level of features, and the valence (positive vs. negative) of the preceding feedback during learning. Our results support Rehder and Hoffman's observations that gaze on the low diagnosticity feature decreased from the beginning to the end of the task. When change in eye gaze behavior was evaluated in relation to feedback, change in fixation probability was found to be greater following negative feedback. The results indicate that in a category task that includes performance feedback, learning strategies as indicated by changes in selective attention to features are affected to some degree by the valence of the feedback on a preceding trial.

Seeking neurophysiological manifestations of speech production: An ERP study.

The aim of this study was to examine the neurophysiological correlates of speech production by elucidating pertinent ERP components. Such examination can pave way for investigations on typical and atypical speech neuromotor control. Participants completed a speech task by saying a specific word (speaking condition) or withholding the verbal response (non-speaking condition) based on the color of a frame placed around a fixation cross that were displayed on a computer screen. They also completed a simple hand motor task by pressing a button with the right or left index finger based on the color of a frame. The hand motor task was administered to verify that neural activity specific to motor preparation was detectable. Two ERP components emerged from the multichannel principal component analysis (PCA) as distinguishing between the speaking and no speaking conditions: a posterior negative component, and a left lateralized positive component. The morphology of the posterior negative component, as well as the correlation between its magnitude and mean response time suggest that this component is closely associated with speech motor control. The left-lateralized component was interpreted as reflecting a process possibly mediated by the speech dominant left hemisphere.

Effect of orthodontic treatment and comorbidity risk factors on interdental alveolar crest level: A radiographic evaluation.

INTRODUCTION: Alveolar bone loss is regarded as a potential adverse event during orthodontic treatment, especially in adults. The purposes of this study were to evaluate the prevalence and severity of interdental alveolar crest height loss in adult orthodontic patients compared with an untreated control group and to identify comorbidity risk factors for such bone loss (high BMI score, high blood pressure, high cholesterol levels, and smoking). METHODS: Standardized bitewing radiographs of patients' buccal segments were taken before and after treatment of 34 consecutive adults treated in an orthodontic clinic. The control group included 29 patients from the operative dental clinic matched according to age and sex. Mean ages of the participants before treatment were 35.7 ± 6.7 and 35.6 ± 7.3 years for the control and treatment groups, respectively. Before orthodontic treatment, the patients were evaluated, treated as needed, and approved by a periodontist. They were periodontically healthy before treatment. Interdental alveolar crest height loss was calculated by subtracting the distance on a bitewing x-ray from the cementoenamel junction to the interdental alveolar crest at each interproximal tooth surface from the mesial aspect of the first premolar to the distal aspect of the second molar (8 sites per quadrant). Changes in interdental alveolar crest height were calculated by subtracting the cementoenamel junction-interdental alveolar crest distance before treatment from the corresponding distance after treatment. RESULTS: The mean individual bone losses of all interproximal surfaces were 0.130 ± 0.192 and 0.072 ± 0.280 mm in the treatment and control groups, respectively. These differences did not reach statistical significance (P = 0.353). Twenty-two patients (65%) from the treatment group and 10 patients (34%) from the control group had an increase in the cementoenamel junction-interdental alveolar crest distance of more than 1 mm in at least 1 site, with borderline significance between the groups (P = 0.079). Notably, no association was observed between bone loss with any comorbidity factor. CONCLUSIONS: The results of this study correspond to the conventional understanding in the orthodontic and periodontal literature that orthodontic tooth movement per se does not cause attachment loss. However, orthodontists should always be aware of the possibility of periodontal deterioration during orthodontic treatment. Therefore, comprehensive periodontal examination is necessary during orthodontic treatment, especially in adults.

Developmental changes in the feedback related negativity from 8 to 14 years.

The study examined age related changes in the magnitude of the Feedback Related Negativity (FRN) in 8-14 year old children performing a variation of a Go/No-Go task. Participants were presented with four stimuli and tasked with mapping each of them either to a response or to a "no response" by trial and error guided by feedback. Feedback was valid for two stimuli (Go and No-Go) and invalid (.5 positive; .5 negative feedback) for the other two stimuli. The amplitude of the FRN was evaluated as a function of age separately for Go and No-Go trials. The results indicated that while performance on valid Go trials improved with age, accuracy on valid No-Go trials remained stable with age. FRN amplitude was found to be inversely related to age such that smaller FRN amplitudes were observed in older children even after controlling for variance in learning. Additionally, the FRN was found as a predictor of post-learning performance on Go trials but not on No-Go trials, regardless of age. These results do not provide support to the link between the FRN and inhibition control as measured by No-Go performance, but do suggest a link with other executive control abilities called for by the Go condition.

It's all about timing: An electrophysiological examination of feedback-based learning with immediate and delayed feedback.

Feedback regarding an individual's action can occur immediately or with a temporal delay. Processing of feedback that varies in its delivery time is proposed to engage different brain mechanisms. fMRI data implicate the striatum in the processing of immediate feedback, and the medial temporal lobe (MTL) in the processing of delayed feedback. The present study offers an electrophysiological examination of feedback processing in the context of timing, by studying the effects of feedback timing on the feedback-related negativity (FRN), a product of the midbrain dopamine system, and elucidating whether the N170 ERP component could capture MTL activation associated with the processing of delayed feedback. Participants completed a word-object paired association learning task; they received feedback 500ms (immediate feedback condition) following a button press during the learning of two sets of 14 items, and at a delay of 6500ms (delayed feedback condition) during the learning of the other two sets. The results indicated that while learning outcomes did not differ under the two timing conditions, Event Related Potential (ERPs) pointed to differential activation of the examined ERP components. FRN amplitude was found to be larger following the immediate feedback condition when compared with the delayed feedback condition, and sensitive to valence and learning only under the immediate feedback condition. Additionally, the amplitude of the N170 was found larger following the delayed feedback condition when compared with the immediate feedback condition. Taken together, the findings of the present study support the contention that the processing of delayed feedback involves a shift away from midbrain dopamine activation to the recruitment of the MTL.

A Neurophysiological examination of quality of learning in a feedback-based learning task.

The efficiency with which one processes external feedback contributes to the speed and quality of one's learning. Previous findings that the feedback related negativity (FRN) event related potential (ERP) is modulated by learning outcomes suggested that this ERP reflects the extent to which feedback is used by the learner to improve performance. To further test this suggestion, we measured whether the FRN and the fronto-central positivity (FCP) that follows it are modulated by learning slopes, and as a function of individual differences in learning outcomes. Participants were tasked with learning names (non-words) of 42 novel objects in a two-choice feedback-based visual learning task. The items were divided into three sets of 14 items, each presented in five learning blocks and a sixth test block. Individual learning slopes based on performance on the task, as well as FRN and FCP slopes based on positive and negative feedback related activation in each block were created for 53 participants. Our data pointed to an interaction between slopes of the FRN elicited by negative feedback and learning slopes, such that a sharper decrease in the amplitude of the FRN to negative feedback was associated with sharper learning slopes. We further examined the predictive power of the FRN and FCP elicited in the training blocks on the learning outcomes as measured by performance on the test blocks. We found that small FRN to negative feedback, large FRN to positive feedback, and large FCP to negative feedback in the first training block predicted better learning outcomes. These results add to the growing evidence that the processes giving rise to the FRN and FCP are sensitive to individual differences in the extent to which feedback is used for learning.

International medical leadership, collaboration and communication.

BACKGROUND: International social networking is eminent in medical practice, mainly in sharing knowledge and mutual inspiring and in social and professional bonding. Since 2006, the International Medical Course is taking place in Commander Branch at the Military Medicine Academy of the Medical Corps, Israeli Defense Forces; in which medical officers from other military forces are participating along with Israeli officers. One of the course's objectives is international networking. The purpose of this study was to assess the level of networking in the International Medical Course compared to others means of networking, and to examine which components in the course are the most important in networking formation. METHODS: Questionnaires were e-mailed to the course participants. Demographic data and data regarding the networking possibilities in the international medical course was collected. RESULTS: The answers of 35 participants (17 Majors, 12 Lieutenant-Colonels, and 6 Colonels; mean age of 44.1 years) were included in this study. Response rate was 42%. Of the participants, 24 were Israelis and 11 from other military forces. Most of the responders (88.6%) reported the course is a major networking tool, with no influence of age, sex, rank, education profession or origin. Networking potential among participants from the same origin country was significantly higher in Israeli officers in comparison to officers from other countries (p = 0.001). Clinical practice and research purposes were the reason for communication in one fifth of the participants. CONCLUSIONS: The International Medical Course fulfils its purpose in forming international military medical networking.