The right time to learn: mechanisms and optimization of spaced learning

Brief memory reactivation may not improve visual perception

Visual perceptual learning often requires a substantial number of trials to observe significant learning effects. Previously Amar-Halpert et al. (2017) have shown that brief reactivation (5 trials/day) is sufficient to improve the performance of the texture discrimination task (TDT), yielding comparable improvements to those achieved through full practice (252 trials/day). The finding is important since it would refine our understanding of learning mechanisms and applications. In the current study, we attempted to replicate these experiments using a larger number of observers and an improved experimental design. Using between-group comparison, we did find significant improvements in the reactivation group and the full-practice group as Amar-Halpert et al. (2017) showed. However, these improvements were comparable to those of the no-reactivation group with no exposure to the TDT task over the same period. Importantly, our within-group comparison showed that both the reactivation and no-reactivation groups exhibited additional significant improvements after further practicing the TDT task for an additional three days, demonstrating that the full-practice effect was significantly superior to the effects of brief memory reactivation or simple test-retest. Besides, when refining the constant stimuli method with fewer stimulus levels and more trials per level, we still observed comparable improvements brought by the reactivation and no-reactivation groups. Therefore, our results suggested that brief memory reactivation may not significantly contribute to the improvement of perceptual learning, and traditional perceptual training could still be a necessary and effective approach for substantial improvements.

Benefits of spaced learning are predicted by the re-encoding of past experience in ventromedial prefrontal cortex

More than a century of research shows that spaced learning improves long-term memory. However, there remains debate concerning why that is. A major limitation to resolving theoretical debates is the lack of evidence for how neural representations change as a function of spacing. Here, leveraging a massive-scale 7T human fMRI dataset, we tracked neural representations and behavioral expressions of memory as participants viewed thousands of natural scene images that repeated at lags ranging from seconds to many months. We show that spaced learning increases the similarity of human ventromedial prefrontal cortex representations across stimulus encounters and, critically, that these increases parallel and predict the behavioral benefits of spacing. Additionally, we show that these spacing benefits critically depend on remembering and, in turn, "re-encoding" past experience. Collectively, our findings provide fundamental insight into how spaced learning influences neural representations and why spacing is beneficial.

Repeated tDCS at clinically-relevant field intensity can boost concurrent motor learning in rats

Electric fields used in clinical trials with transcranial direct current stimulation (tDCS) are small, with magnitudes that have yet to demonstrate measurable effects in preclinical animal models. We hypothesized that weak stimulation will nevertheless produce sizable effects, provided that it is applied concurrently with behavioral training, and repeated over multiple sessions. We tested this here in a rodent model of dexterous motor-skill learning. We developed a preparation that allows concurrent stimulation during the performance of a pellet-reaching task in freely behaving rats. The task was automated to minimize experimenter bias. We measured field magnitudes intracranially to calibrate the stimulation current. In this study, only male rats were used. Animals were trained for 20 min with concurrent epicranial tDCS over 10 daily sessions. Behavior was recorded with high-speed video to quantify reaching dynamics. We also measured motor-evoked potentials (MEPs) bilaterally with epidural microstimulation. The new electrode montage enabled stable stimulation over 10 sessions with a field intensity of 2V/m at the motor cortex. The number of successful reaches improved across days of training, and the rate of learning was higher in the anodal group as compared to sham-control animals (F(1)=7.12, p=0.008, N=24). MEPs were not systematically affected by tDCS. Posthoc analysis suggests that tDCS modulated motor learning only for right-pawed animals, improving success of reaching, but limiting stereotypy in these animals. Repeated and concurrent anodal tDCS can boost motor-skill learning at clinically-relevant field intensities. In this animal model the effect interacted with paw preference and was not associated with corticospinal excitability.

Significance Statement

The effects of tDCS have been explored in numerous human clinical trials, but the mechanisms of action of weak electric fields remain unclear. In vitro studies show that constant electric fields at 2.5 V/m can enhance the efficacy of synapses undergoing plasticity. This study demonstrates in a rodent model that tDCS of only 2 Vm when applied concurrently to behavioral training can improve motor skill learning, and reduce stereotypy of reaching behavior. These effects accumulated over 10 days of training. Motor evoked potentials (MEP), which are often used to demonstrate plastic effects in humans on a time scale of hours, were not measurably affected by tDCS on this longer time scale.

Perceptions and Use of Extended-Duration Exposure Therapy Amongst Psychologists

BACKGROUND

Extended-duration exposure therapy, in which treatment is delivered over a single prolonged session or cluster of long-duration sessions, is a highly efficacious and efficient treatment for anxiety disorders such as specific phobias. Despite this, little is known about the use of extended-duration exposure therapy in clinical practice.

METHODS

In the present study we investigated the perceptions and use of extended-duration exposure therapy amongst a sample of Australian psychologists via a survey, and the Therapist Beliefs about Exposure Scale. Additionally, we compared theoretical understanding of exposure therapy, and therapy delivery strategies (using a case study vignette), between psychologists who deliver exposure therapy via an extended-duration mode, versus the more traditional multi-session mode.

RESULTS

Extended-duration exposure therapy is widely underutilised, and this is associated with negative beliefs about exposure therapy in general, as well as several practical barriers. There were no differences in the reported theoretical mechanisms of exposure therapy between those who do and do not use extended-duration exposure therapy. However, psychologists who use extended-duration exposure therapy reported greater use of strategies with demonstrated efficacy (e.g., more intense delivery) and less use of therapy-interfering strategies (e.g., distress reduction techniques) relative to those who do not use extended-duration exposure therapy.

CONCLUSION

These findings identify potential mechanisms accounting for extended-duration exposure therapy's efficiency and point to strategies that may increase the uptake of extended-duration exposure therapy in clinical practice.

A synapse-specific refractory period for plasticity at individual dendritic spines

How newly formed memories are preserved while brain plasticity is ongoing has been a source of debate. One idea is that synapses which experienced recent plasticity become resistant to further plasticity, a type of metaplasticity often referred to as saturation. Here, we probe the local dendritic mechanisms that limit plasticity at recently potentiated synapses. We show that recently potentiated individual synapses exhibit a synapse-specific refractory period for further potentiation. We further found that the refractory period is associated with reduced postsynaptic CaMKII signaling; however, stronger synaptic activation fully restored CaMKII signaling but only partially restored the ability for further plasticity. Importantly, the refractory period is released after one hour, a timing that coincides with the enrichment of several postsynaptic proteins to preplasticity levels. Notably, increasing the level of the postsynaptic scaffolding protein, PSD95, but not of PSD93, overcomes the refractory period. Our results support a model in which potentiation at a single synapse is sufficient to initiate a synapse-specific refractory period that persists until key postsynaptic proteins regain their steady-state synaptic levels.

Bursty, Irregular Speech Input to Children Predicts Vocabulary Size

Children learn language by listening to speech from caregivers around them. However, the type and quantity of speech input that children are exposed to change throughout early childhood in ways that are poorly understood due to the small samples (few participants, limited hours of observation) typically available in developmental psychology. Here we used child-centered audio recorders to unobtrusively measure speech input in the home to 292 children (aged 2-7 years), acquiring English in the United States, over 555 distinct days (approximately 8600 total hours of observation, or 29.62 h/child). These large timescales allowed us to compare how different dimensions of child-directed speech input (quantity, burstiness) varied throughout early childhood. We then evaluated the relationship between each dimension of input and children's concurrent receptive vocabulary size. We found that the burstiness of speech input (spikes of words) was a stronger correlate with age than the quantity of speech input. Input burstiness was also a stronger predictor than input quantity for children's vocabulary size: children who heard spiky, more intense bouts of input had larger vocabularies. Overall, these results reaffirm the importance of speech input in the home for children's language development and support exposure-consolidation models of early language development.

The impact of temporal distribution on fear extinction learning

Fear extinction is the foundation of exposure therapy for anxiety and phobias. However, the stability of extinction memory diminishes over time, coinciding with fear recovery. To augment long-term extinction retention, the temporal distribution of extinction learning sessions is critical. This study investigated the effects of massed and spaced training (with short and long intervals) on extinction retention compared to a classic protocol. 120 healthy participants were recruited and randomly divided to massed training, spaced training with 20-minutes or 3-hours intervals, and a control group. The control group completed half the number of extinction trials compared to the other groups. The fear conditioning/extinction paradigm consisted of three consecutive days of fear acquisition, extinction, and recall, followed by a second recall one week later. Skin conductance response (SCR) and self-rating questionnaires (ratings of valence, arousal, and fear) were recorded and analyzed using mixed model ANOVAs. The results revealed that during the extinction phase, both massed and spaced protocols showed significantly lower SCRs compared to the control group, with massed training resulting in the largest effects. In the second recall, only the massed extinction group showed no significant difference in SCRs between threat and safety cues. The self-report assessments indicated that the massed extinction group showed furthermore lower arousal than the control group in the first recall. These results suggest that both massed and spaced training promote fear extinction learning, but only massed training improves long-term extinction retention. This study highlights the impact of the temporal distribution and trial number of extinction learning on extinction retention, offering insights for future research on improving fear extinction efficacy.

Enhancing cosmetic suturing skill acquisition in surgical residents through spaced learning training: a randomized controlled trial

BACKGROUND

Previous research has strongly supported the utility of spaced learning in enhancing memory, but its effectiveness in complex surgical procedures has largely been unexplored. The main objective of this study was to evaluate whether, in comparison to concentrated learning, spaced learning improves the short-term acquisition and long-term retention of cosmetic suturing skills as outcomes of surgical resident training courses.

METHODS

This randomized controlled trial was conducted from February 2023 to June 2023. Surgical residents were recruited from a teaching hospital in Guangzhou, China. The participants were randomly assigned at a 1:1 ratio to either the spaced training group (40 min of training followed by a 20-minute break) or the concentrated training group (3 h of continuous training), in which they received one-on-one training for cosmetic suturing skills. The short-term acquisition and long-term retention outcomes were evaluated by three independent raters using an objective scoring scale to assess the participants' cosmetic suturing skills before the training (pretraining test), within one hour after the training (posttraining test), and three months after the completion of the training (follow-up test). The score for each participant was calculated as the average of three independent scores.

RESULTS

The study included 23 surgical residents, 12 in the spaced training group and 11 in the concentrated training group. The pretraining test revealed no significant difference between the groups. However, in the post-training test, the spaced training group achieved a significantly higher total score than did the concentrated training group (74.06 ± 5.87 vs. 63.43 ± 10.73, p = 0.0070). Specifically, the suture technique scores were 28.46 ± 1.78 and 22.85 ± 3.75, respectively, which were significantly different (p = 0.0002). During the long-term follow-up test, the spaced training group consistently outperformed the concentrated training group by having significantly higher total (75.60 ± 4.78 vs. 60.68 ± 10.40, p = 0.0001), suture quality (32.26 ± 4.01 vs. 26.23 ± 4.16, p = 0.0019), suture technique (28.68 ± 2.63 vs. 22.18 ± 3.94, p = 0.0001), and suturing time scores (14.67 ± 1.15 vs. 12.27 ± 6.07, p = 0.0460).

CONCLUSIONS

Incorporating the principles of spaced learning into the instructional process of obtaining cosmetic suture skills for surgical residents not only significantly enhances short-term skill improvement but also contributes to the long-term retention of training outcomes.

Rats show up to 72 h of significant retention for spatial memory in the radial maze

This study explored long-term retention of spatial memory in rats using an eight-arm radial maze. Crystal and Babb (Learning and motivation, 39(4), 278-284, 2008) previously demonstrated that rats could retain spatial memory for up to 25 h in the radial maze. Notably, they found performance improved with 48-h intertrial intervals compared with 24-h intervals. Our study investigated the effects of extending intertrial intervals on long-term retention of spatial memory by reducing the potential for proactive interference. Each trial comprised a learning phase, during which subjects were required to sequentially visit four randomly selected arms, followed by a free-choice test that included all eight arms, conducted after increasing the retention and intertrial intervals. The retention intervals were systematically increased from 1 h to 24, 48, and, ultimately, 72 h, with corresponding intertrial intervals expanding from 24 to 48, 120, and 144 h. Performance significantly surpassed chance levels across all conditions, demonstrating that rats are capable of retaining spatial memory for up to 72 h.

The massed-spaced learning effect in non-neural human cells

The massed-spaced effect is a hallmark feature of memory formation. We now demonstrate this effect in two separate non-neural, immortalized cell lines stably expressing a short-lived luciferase reporter controlled by a CREB-dependent promoter. We emulate training using repeated pulses of forskolin and/or phorbol ester, and, as a proxy for memory, measure luciferase expression at various points after training. Four spaced pulses of either agonist elicit stronger and more sustained luciferase expression than a single "massed" pulse. Spaced pulses also result in stronger and more sustained activation of molecular factors critical for memory formation, ERK and CREB, and inhibition of ERK or CREB blocks the massed-spaced effect. Our findings show that canonical features of memory do not necessarily depend on neural circuitry, but can be embedded in the dynamics of signaling cascades conserved across different cell types.

The Student Voice: Perceptions of Durable Learning

BACKGROUND

Durable learning is the teaching/learning methods that result in retained knowledge that can be transferred to practice. There is limited research on durable learning in nursing education (NE).

PURPOSE

The purpose of this study was to understand the perceptions of how learners acquire and retain knowledge.

METHODS

Nursing students and recent graduates were recruited from 2 large universities. Focus groups (n = 7) were audio-recorded, and transcripts were analyzed.

RESULTS

Thematic analysis of learners' perceptions revealed (1) effective learner-initiated techniques, (2) effective instructor-initiated techniques, (3) learner-initiated techniques that were not effective, and (4) instructor-initiated techniques in the classroom, clinical practice, and simulation that were not effective.

CONCLUSION

Additional research is needed to understand faculty perspectives on durable learning techniques and their effectiveness. Findings from student, graduate, and faculty perspectives will guide the development of a validated, reliable tool to evaluate durable learning in NE.

A novel dual-site OFC-dlPFC accelerated repetitive transcranial magnetic stimulation for depression: a pilot randomized controlled study

BACKGROUND

This study aimed to evaluate a novel rTMS protocol for treatment-resistant depression (TRD), using an EEG 10-20 system guided dual-target accelerated approach of right lateral orbitofrontal cortex (lOFC) inhibition followed by left dorsolateral prefrontal cortex (dlPFC) excitation, along with comparing 20 Hz dlPFC accelerated TMS v. sham.

METHODS

Seventy five patients participated in this trial consisting of 20 sessions over 5 consecutive days comparing dual-site (cTBS of right lOFC followed sequentially by 20 Hz rTMS of left dlPFC), active control (sham right lOFC followed by 20 Hz rTMS of left dlPFC) and sham control (sham for both targets). Resting-state fMRI was acquired prior to and following treatment.

RESULTS

Hamilton Rating Scale for Depression (HRSD-24) scores were similarly significantly improved at 4 weeks in both the Dual and Single group relative to Sham. Planned comparisons immediately after treatment highlighted greater HRSD-24 clinical responders (Dual: 47.8% v. Single:18.2% v. Sham:4.3%, χ2 = 13.0, p = 0.002) and in PHQ-9 scores by day 5 in the Dual relative to Sham group. We further showed that accelerated 20 Hz stimulation targeting the left dlPFC (active control) is significantly better than sham at 4 weeks. Dual stimulation decreased lOFC-subcallosal cingulate functional connectivity. Greater baseline lOFC-thalamic connectivity predicted better therapeutic response, while decreased lOFC-thalamic connectivity correlated with better response.

CONCLUSIONS

Our novel accelerated dual TMS protocol shows rapid clinically relevant antidepressant efficacy which may be related to state-modulation. This study has implications for community-based accessible TMS without neuronavigation and rapid onset targeting suicidal ideation and accelerated discharge from hospital.

Extended course accelerated intermittent theta burst stimulation as a substitute for depressed patients needing electroconvulsive therapy

In response to restrictions on electroconvulsive therapy (ECT) access during COVID-19, we designed a trial to assess the clinical outcomes service impacts, employing an extended course of accelerated intermittent theta burst stimulation (aiTBS), in patients with moderate to severe depression in need of ECT. This open label clinical trial was comprised of 3 phases: (i) an acute phase, where iTBS treatments were administered 8 times daily, for up to 10 days; (ii) a tapering phase of 2 treatment days per week for 2 weeks, followed by 1 treatment day per week for 2 weeks; and (iii) a symptom-based relapse prevention phase, whereby treatments were scheduled based on symptom re-emergence, for up to 6 months. Of the 155 patients who completed the acute phase of the study, the remission rate was 16.1%. The mean reduction from baseline on the HRSD-24 was 29.4% (p < 0.001) and the response rate was 25.2%. Of the 110 patients who completed the tapering phase, the mean reduction from baseline was 42.6% (p < 0.001) and response and remission rates were 49.6% and 34.8%, respectively. Of the 61 patients who were eligible for the relapse prevention phase, 43 completed, with a mean reduction from baseline of 60.1% (p < 0.001); 7 patients relapsed during this phase. This study demonstrated that an extended aiTBS protocol safely led to meaningful clinical outcomes in patients with severe depression, who otherwise would have received ECT, and thus reduced pressure on ECT services during the pandemic. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04384965 ( https://clinicaltrials.gov/study/NCT04384965?term=NCT04384965&rank=1 ).

Randomised controlled trial comparing different intersession intervals of intermittent theta burst delivered to the dorsal medial prefrontal cortex

BACKGROUND

Intermittent theta burst stimulation (iTBS) is a form of repetitive transcranial magnetic stimulation (rTMS) that can be administered in a fraction of the time of standard rTMS. Applying multiple daily iTBS sessions (ie, accelerated iTBS) may enable patients to achieve remission more rapidly. However, questions remain regarding the optimal time interval between treatment sessions.

OBJECTIVE

The overall aim of this study was to compare the efficacy and tolerability of two accelerated bilateral iTBS protocols (ie, 30-min or 60-min intervals) and a once-daily bilateral iTBS protocol (ie, 0-min interval) while the number of pulses was held constant, in patients with treatment-resistant depression (TRD).

METHODS

182 patients with TRD were randomised to receive two sessions per day of bilateral iTBS of the dorsomedial prefrontal cortex (DMPFC) at 60-min, 30-min or 0-min intervals. Sham treatments were delivered using a shielded 'sham coil' which produced the auditory and tactile sensations of stimulation. The primary outcome measure was a change in depression scores on the 17-item Hamilton Rating Scale for Depression (HRSD-17) after 20 days of treatment.

RESULTS

HRSD-17 scores improved across all groups; however, these improvements did not significantly differ between the three groups after 20 days of treatment. Similarly, response and remission rates did not differ between the treatment groups.

CONCLUSIONS

These results suggest that contrary to our original hypothesis, implementing a 30-min or 60-min interval between two treatment sessions of DMPFC-iTBS does not lead to a more rapid improvement in symptoms, than once-daily iTBS administration.

TRIAL REGISTRATION NUMBER

NCT02778035.

Differential analgesic effects of high-frequency or accelerated intermittent theta burst stimulation of M1 on experimental tonic pain: Correlations with cortical activity changes assessed by TMS-EEG

Accelerated intermittent theta burst stimulation (AiTBS) has attracted much attention in the past few years as a new form of brain stimulation paradigm. However, it is unclear the relative efficacy of AiTBS on cortical excitability compared to conventional high-frequency rTMS. Using concurrent TMS and electroencephalogram (TMS-EEG), this study systematically compared the efficacy on cortical excitability and a typical clinical application (i.e. pain), between AiTBS with different intersession interval (ISIs) and 10-Hz rTMS. Participants received 10-Hz rTMS, AiTBS-15 (3 iTBS sessions with a 15-min ISI), AiTBS-50 (3 iTBS sessions with a 50-min ISI), or Sham stimulation over the primary motor cortex on four separate days. All four protocols included a total of 1800 pulses but with different session durations (10-Hz rTMS ​= ​18, AiTBS-15 ​= ​40, and AiTBS-50 ​= ​110 ​min). AiTBS-50 and 10-Hz rTMS were more effective in pain reduction compared to AiTBS-15. Using single-pulse TMS-induced oscillation, our data revealed low gamma oscillation as a shared cortical excitability change across all three active rTMS protocols but demonstrated completely opposite directions. Changes in low gamma oscillation were further associated with changes in pain perception across the three active conditions. In contrast, a distinct pattern of TMS-evoked potentials (TEPs) was revealed, with 10-Hz rTMS decreasing inhibitory N100 amplitude and AiTBS-15 reducing excitatory P60 amplitude. These changes in TEPs were also covarying with low gamma power changes. Sham stimulation indicated no significant effect on either cortical excitability or pain perception. These results are relevant only for provoked experimental pain, without being predictive for chronic pain, and revealed a change in low gamma oscillation, particularly around the very particular frequency of 40 ​Hz, shared between AiTBS and high-frequency rTMS. Conversely, cortical excitability (balance between excitation and inhibition) assessed by TEP recording was modulated differently by AiTBS and high-frequency rTMS paradigms.

Dopamine-mediated interactions between short- and long-term memory dynamics

In dynamic environments, animals make behavioural decisions on the basis of the innate valences of sensory cues and information learnt about these cues across multiple timescales1-3. However, it remains unclear how the innate valence of a sensory stimulus affects the acquisition of learnt valence information and subsequent memory dynamics. Here we show that in the Drosophila brain, interconnected short- and long-term memory units of the mushroom body jointly regulate memory through dopamine signals that encode innate and learnt sensory valences. By performing time-lapse in vivo voltage-imaging studies of neural spiking in more than 500 flies undergoing olfactory associative conditioning, we found that protocerebral posterior lateral 1 dopamine neurons (PPL1-DANs)4 heterogeneously and bidirectionally encode innate and learnt valences of punishment, reward and odour cues. During learning, these valence signals regulate memory storage and extinction in mushroom body output neurons (MBONs)5. During initial conditioning bouts, PPL1-γ1pedc and PPL1-γ2α'1 neurons control short-term memory formation, which weakens inhibitory feedback from MBON-γ1pedc>α/β to PPL1-α'2α2 and PPL1-α3. During further conditioning, this diminished feedback allows these two PPL1-DANs to encode the net innate plus learnt valence of the conditioned odour cue, which gates long-term memory formation. A computational model constrained by the fly connectome6,7 and our spiking data explains how dopamine signals mediate the circuit interactions between short- and long-term memory traces, yielding predictions that our experiments confirmed. Overall, the mushroom body achieves flexible learning through the integration of innate and learnt valences in parallel learning units sharing feedback interconnections. This hybrid physiological-anatomical mechanism may be a general means by which dopamine regulates memory dynamics in other species and brain structures, including the vertebrate basal ganglia.

Usage of Spaced Repetition Flashcards to Improve Educational Outcomes in Microbiology

Introduction: Spaced repetition flashcards and other instructor-made resources are beneficial tools for students in content-dense introductory courses, particularly in the sciences. This study seeks to evaluate whether instructor-made, spaced repetition flashcards affect students' performance on the exams and their self-concept as it pertains to a newly introduced discipline (microbiology). Methods: Students enrolled in a bachelor's level introductory microbiology course utilized a spaced repetition flashcard software to scaffold their review of course material productively. Exam scores and student perceptual data from institutionally validated surveys were then compared using parametric T-testing. Results: While overall performance on the exams was unchanged (p = 0.2657), there were significant changes in student perception. Most notably, students' confidence in their ability to succeed improved (p = 0.0066), along with their belief that the course made them think like a microbiologist (p = 0.0011). They also felt that this was an effective instructional approach (p = 0.0076). Conclusion: These results suggest that students can better engage with and feel confident in understanding the material presented, even if their exam scores did not drastically improve. Further studies should evaluate how resources like the one trialed here can be implemented to improve students' self-concept and learning.

Durability of retrieval-induced forgetting: Effects of different practice schedules

If retrieval-induced forgetting (RIF) is to play a role in the formation of collective memories, it should be long lasting. Although several studies have found that RIF is short-lived, there is other evidence to suggest that repeated selective practice schedules with a temporal gap between each practice trial may increase the durability of RIF. We tested this possibility in three experiments, focusing on socially shared retrieval-induced forgetting (SSRIF). In two experiments, participants studied scientific or story materials, then listened to someone selectively recall the material repeatedly, either in rapid succession or over an extended time period, and finally recalled the original materials either immediately, after a 1-week delay, or after a 3-week delay. A third experiment examined selective practice in free-flowing conversations. In each instance, RIF was found with repeated selective practice with a temporal gap between trials. The results are discussed in terms of the role RIF might play in the formation of collective memory.

Reward timescale controls the rate of behavioural and dopaminergic learning

Learning the causes of rewards is necessary for survival. Thus, it is critical to understand the mechanisms of such a vital biological process. Cue-reward learning is controlled by mesolimbic dopamine and improves with spacing of cue-reward pairings. However, whether a mathematical rule governs such improvements in learning rate, and if so, whether a unifying mechanism captures this rule and dopamine dynamics during learning remain unknown. Here, we investigate the behavioral, algorithmic, and dopaminergic mechanisms governing cue-reward learning rate. Across a range of conditions in mice, we show a strong, mathematically proportional relationship between both behavioral and dopaminergic learning rates and the duration between rewards. Due to this relationship, removing up to 19 out of 20 cue-reward pairings over a fixed duration has no influence on overall learning. These findings are explained by a dopamine-based model of retrospective learning, thereby providing a unified account of the biological mechanisms of learning.

Validation and efficacy of the Varix Trainer model as a Training device for esophagogastroduodenoscopy

Background and study aims The Varix Trainer model 1 (VTM1) was created for trainees to safely practice basic endoscope manipulation skills. The VTM1 was tested to see if it could distinguish levels of endoscope manipulation skills (construct validity) and whether training with it could improve these skills faster (content validity). Patients and methods We enrolled 23 novice endoscopists, 18 second-year trainees, and 13 expert endoscopists. They were asked to point with the endoscope tip to 20 numbers in the model as quickly as possible using torque, single-hand small/large wheel manipulation (SHSW), and retroflexion techniques. Their mean times (t20) were compared to determine if the model could distinguish different levels of expertise. Subsequently, 14 novices trained for eight short sessions, and the pre-training and post-training t20 were compared. Nine novice endoscopists received no training and were retested after 4 to 6 weeks (controls). Results Experts had faster t20 than second-year trainees, who were faster than novices, for all three techniques ( P < 0.001). After eight sessions, the mean t20 for novices improved from 112 to 66 seconds for torque, 144 to 72 seconds for SHSW, and 108 to 63 seconds for retroflexion, (all P < 0.001). Their t20 were equivalent to second-year trainees. Improvement in t20 was also seen with the control group, but total reduction was less than for the training group. Conclusions The VTM1 distinguished varying levels of expertise for all techniques, suggesting that it is a valid tool for assessing endoscope manipulation skill. A short curriculum improved novices' manipulation skills faster than traditional practice.

Improving efficacy of repetitive transcranial magnetic stimulation for treatment of Parkinson disease gait disorders

Parkinson disease (PD) is a neurodegenerative disorder that causes motor and cognitive deficits, presenting complex challenges for therapeutic interventions. Repetitive transcranial magnetic stimulation (rTMS) is a type of neuromodulation that can produce plastic changes in neural activity. rTMS has been trialed as a therapy to treat motor and non-motor symptoms in persons with Parkinson disease (PwP), particularly treatment-refractory postural instability and gait difficulties such as Freezing of Gait (FoG), but clinical outcomes have been variable. We suggest improving rTMS neuromodulation therapy for balance and gait abnormalities in PwP by targeting brain regions in cognitive-motor control networks. rTMS studies in PwP often targeted motor targets such as the primary motor cortex (M1) or supplementary motor area (SMA), overlooking network interactions involved in posture-gait control disorders. We propose a shift in focus toward alternative stimulation targets in basal ganglia-cortex-cerebellum networks involved in posture-gait control, emphasizing the dorsolateral prefrontal cortex (dlPFC), cerebellum (CB), and posterior parietal cortex (PPC) as potential targets. rTMS might also be more effective if administered during behavioral tasks designed to activate posture-gait control networks during stimulation. Optimizing stimulation parameters such as dosage and frequency as used clinically for the treatment of depression may also be useful. A network-level perspective suggests new directions for exploring optimal rTMS targets and parameters to maximize neural plasticity to treat postural instabilities and gait difficulties in PwP.

The Use of a Novel Virtual Reality Training Tool for Peritoneal Dialysis: Qualitative Assessment Among Health Care Professionals

BACKGROUND

Effective peritoneal dialysis (PD) training is essential for performing dialysis at home and reducing the risk of peritonitis and other PD-related infections. Virtual reality (VR) is an innovative learning tool that is able to combine theoretical information, interactivity, and behavioral instructions while offering a playful learning environment. To improve patient training for PD, Fresenius Medical Care launched the stay•safe MyTraining VR, a novel educational program based on the use of a VR headset and a handheld controller.

OBJECTIVE

This qualitative assessment aims to investigate opinions toward the new tool among the health care professionals (HCPs) who were responsible for implementing the VR application.

METHODS

We recruited nursing staff and nephrologists who have gained practical experience with the stay•safe MyTraining VR within pilot dialysis centers. Predetermined open-ended questions were administered during individual and group video interviews.

RESULTS

We interviewed 7 HCPs who have 2 to 20 years of experience in PD training. The number of patients trained with the stay•safe MyTraining VR ranged from 2 to 5 for each professional. The stay•safe MyTraining VR was well accepted and perceived as a valuable supplementary tool for PD training. From the respondents' perspective, the technology improved patients' learning experience by facilitating the internalization of both medical information and procedural skills. HCPs highlighted that the opportunity offered by VR to reiterate training activities in a positive and safe learning environment, according to each patient's needs, can facilitate error correction and implement a standardized training curriculum. However, VR had limited use in the final phase of the patient PD training program, where learners need to get familiar with the handling of the materials. Moreover, the traditional PD training was still considered essential to manage the emotional and motivational aspects and address any patient-specific application-oriented questions. In addition to its use within PD training, VR was perceived as a useful tool to support the decision-making process of patients and train other HCPs. Moreover, VR introduction was associated with increased efficiency and productivity of HCPs because it enabled them to perform other activities while the patient was practicing with the device. As for patients' acceptance of the new tool, interviewees reported positive feedback, including that of older adults. Limited use with patients experiencing dementia or severe visual impairment or lacking sensomotoric competence was mentioned.

CONCLUSIONS

The stay•safe MyTraining VR is suggested to improve training efficiency and efficacy and thus could have a positive impact in the PD training scenario. Our study offers a process proposal that can serve as a guide to the implementation of a VR-based PD training program within other dialysis centers. Dedicated research is needed to assess the operational benefits and the consequences on patient management.

A comparison of 1- versus 3-month regional anatomy exposure on learning outcomes of undergraduate medical students

Regional anatomy teaching forms a cornerstone of undergraduate medical education. Owing to an increase in teaching and learning content throughout the medical curriculum in recent years, contact hours and overall course durations in anatomy are under review worldwide. This study aimed to assess whether shortening the course content duration impacts learning gain and the ability to identify anatomical structures correctly. Undergraduate medical students of the Johannes Kepler University Linz (JKU; n = 310) and at the Medical University of Graz (MUG; n = 156) participating in regional anatomy courses were included. Whole body regional anatomy courses, including hands-on dissection and accompanying lectures, were delivered over one or three months. Course content and examination mode were kept consistent, while the duration of knowledge delivery was one or three months, respectively. Objective structured practical examinations (OSPE) were then carried out on prosections for the neck, thorax, and abdomen. 3-month course exposure resulted in significantly higher OSPE scores for the neck (49 vs. 37%), thorax (65 vs. 54%), and abdomen (65 vs. 45%), respectively. Further evaluation of the utility of different embalming types yielded higher 3-month scores in the neck and thorax regions with Thiel-embalmed tissues and thorax and abdomen regions in ethanol-glycerin-embalmed tissues. Course exposure over a more extended period, like three months, appears to be highly beneficial.

The neuroscience of active learning and direct instruction

Throughout the educational system, students experiencing active learning pedagogy perform better and fail less than those taught through direct instruction. Can this be ascribed to differences in learning from a neuroscientific perspective? This review examines mechanistic, neuroscientific evidence that might explain differences in cognitive engagement contributing to learning outcomes between these instructional approaches. In classrooms, direct instruction comprehensively describes academic content, while active learning provides structured opportunities for learners to explore, apply, and manipulate content. Synaptic plasticity and its modulation by arousal or novelty are central to all learning and both approaches. As a form of social learning, direct instruction relies upon working memory. The reinforcement learning circuit, associated agency, curiosity, and peer-to-peer social interactions combine to enhance motivation, improve retention, and build higher-order-thinking skills in active learning environments. When working memory becomes overwhelmed, additionally engaging the reinforcement learning circuit improves retention, providing an explanation for the benefits of active learning. This analysis provides a mechanistic examination of how emerging neuroscience principles might inform pedagogical choices at all educational levels.

Evaluating the online Resilience Skills Enhancement programme among undergraduate students: A double-blind parallel randomized controlled trial

Resilience training has beneficial effects on the ability of undergraduate students to withstand adversity and stress. However, there are inconsistencies in the content and delivery approaches for resilience training. Given the increasing shifts towards computer-assisted instruction, there is a need to develop and evaluate innovative approaches for resilience training. This study aimed to examine the efficacy of two versions of the Resilience Skills Enhancement (RISE) programme. A randomized controlled trial was used to evaluate the effects of blended learning (BL) and a self-guided RISE programme on the resilience, social support, and learning outcomes of undergraduate students. One hundred and fourteen students were recruited and randomly allocated to receive either BL or the self-guided RISE programme. The within-group analyses indicated significant improvements in resilience scores for the BL (F = 37.74, p < 0.001) and self-guided groups (F = 10.16, p < 0.001) with moderate (d = 0.62, 95% CI: 0.25, 1.00) to large effect sizes (d = 1.11, 95% CI: 0.71, 1.50) respectively. There were also significant differences across the three time points for social support scores for the BL (F = 4.50, p < 0.05) and self-guided groups (F = 4.59, p < 0.05). Students in the BL group had considerable improvements in self-efficacy of learning and performance (F = 5.42, p < 0.01) and meta-cognitive self-regulation scores (F = 5.91, p < 0.01). In the between-group analyses, both BL and self-guided RISE were comparable for resilience, social support, and learning scores (p > 0.05). The study provided preliminary evidence that both modes, BL and self-guided RISE programme lead to positive effects on the resilience, social support, and learning scores of students.

Contributions of site- and sex-specific LTPs to everyday memory

Commentaries about long-term potentiation (LTP) generally proceed with an implicit assumption that largely the same physiological effect is sampled across different experiments. However, this is clearly not the case. We illustrate the point by comparing LTP in the CA3 projections to CA1 with the different forms of potentiation in the dentate gyrus. These studies lead to the hypothesis that specialized properties of CA1-LTP are adaptations for encoding unsupervised learning and episodic memory, whereas the dentate gyrus variants subserve learning that requires multiple trials and separation of overlapping bodies of information. Recent work has added sex as a second and somewhat surprising dimension along which LTP is also differentiated. Triggering events for CA1-LTP differ between the sexes and the adult induction threshold is significantly higher in females; these findings help explain why males have an advantage in spatial learning. Remarkably, the converse is true before puberty: Females have the lower LTP threshold and are better at spatial memory problems. A mechanism has been identified for the loss-of-function in females but not for the gain-of-function in males. We propose that the many and disparate demands of natural environments, with different processing requirements across ages and between sexes, led to the emergence of multiple LTPs. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.

Synapse-specific structural plasticity that protects and refines local circuits during LTP and LTD

Synapses form trillions of connections in the brain. Long-term potentiation (LTP) and long-term depression (LTD) are cellular mechanisms vital for learning that modify the strength and structure of synapses. Three-dimensional reconstruction from serial section electron microscopy reveals three distinct pre- to post-synaptic arrangements: strong active zones (AZs) with tightly docked vesicles, weak AZs with loose or non-docked vesicles, and nascent zones (NZs) with a postsynaptic density but no presynaptic vesicles. Importantly, LTP can be temporarily saturated preventing further increases in synaptic strength. At the onset of LTP, vesicles are recruited to NZs, converting them to AZs. During recovery of LTP from saturation (1-4 h), new NZs form, especially on spines where AZs are most enlarged by LTP. Sentinel spines contain smooth endoplasmic reticulum (SER), have the largest synapses and form clusters with smaller spines lacking SER after LTP recovers. We propose a model whereby NZ plasticity provides synapse-specific AZ expansion during LTP and loss of weak AZs that drive synapse shrinkage during LTD. Spine clusters become functionally engaged during LTP or disassembled during LTD. Saturation of LTP or LTD probably acts to protect recently formed memories from ongoing plasticity and may account for the advantage of spaced over massed learning. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.

Efficacy of MRI-guided rTMS for post-traumatic stress disorder by modulating amygdala activity: study protocol for a randomised controlled trial

INTRODUCTION

Post-traumatic stress disorder (PTSD) is a prevalent and severe psychiatric disorder. Repetitive transcranial magnetic stimulation (rTMS) targeting the dorsolateral prefrontal cortex provides limited relief for symptoms of PTSD. This study will be conducted to validate the efficacy of MRI-guided rTMS in targeting the sites most closely associated with the amygdala for patients with PTSD. We hypothesise that the intervention will improve clinical symptoms by decreasing amygdala activity in patients.

METHODS AND ANALYSIS

A randomised, double-blind, sham-controlled trial will be conducted. Forty-eight eligible patients with PTSD will be randomly assigned to receive either active or sham MRI-guided rTMS for 10 consecutive days after the initial MRI scans. MRI scans will be recollected at the end of the intervention. Clinical assessments will be performed at baseline, treatment day 5, treatment day 10, and 2 weeks, 4 weeks, 8 weeks after completion of the intervention to monitor changes in clinical symptoms. The primary assessment outcome is the change in PTSD symptoms between baseline and treatment day 10, as measured by the PTSD Checklist for DSM-5. Repeated measures analysis of variance will be performed using statistical software SPSS V.26.0. The significance level will be set at 0.05.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Ethics Committee of Xijing Hospital in Xi'an, China (KY20222176-X-1), and the trial has been registered on ClinicalTrials.gov. The findings of this trial will be disseminated at academic conferences or published in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

NCT05544110.

Developing inclusive public involvement and engagement activities with secondary school students and educational professionals: a protocol

BACKGROUND

Public involvement and engagement (PI&E) is increasingly recognised as an important component of research. It can offer valuable insights from those with experiential knowledge to improve research quality, relevance, and reach. Similarly, schools are ever more common sites for health research and, more recently, PI&E. However, 'gold-standard' practice is yet to be established, and activities/approaches remain underreported. As a result, knowledge can remain localised or lost. Diversity and inclusion also remains a challenge.

METHODS

This protocol has been informed by UK national guidance, evidence-based frameworks and available implementation literature. It describes both rationale and approach to conducting PI&E activities within a secondary school context. Activities are designed to be engaging, safe and accessible to young people with diverse experiences, with scope to be iteratively developed in line with public collaborator preference.

DISCUSSION

Young people should be architects of their involvement and engagement. Ongoing appraisal and transparency of approaches to PI&E in school settings is crucial. Expected challenges of implementing this protocol include facilitating a safe space for the discussion of sensitive topics, absence and attrition, recruiting students with a diverse range of experiences, and potential knowledge and capacity barriers of both facilitator and contributors. Activities to mitigate these risks are suggested and explored.

Network motifs exhibiting a differential response to spaced and massed inputs

One characteristic of long-term memory is the existence of an inverted U-shaped response to increasing intervals between training sessions, and consequently, an optimal spacing that maximizes memory formation. Current models of this spacing effect focus on specific molecular components and their interactions. Here, we computationally study the underlying network architecture, in particular, the potential of motif dynamics in qualitatively capturing the spacing effect in a manner that is independent of the animal model, biomolecular components, and the timescales involved. We define a common training and test protocol, and computationally identify network topologies that can qualitatively replicate the experimentally observed characteristics of the spacing effect. For 41 motifs derived from fundamental network architectures such as autoregulation, feedback, and feedforward motifs, we tested their capacity to manifest the spacing effect in terms of an inverted U-shaped response curve, using different combinations of stimulation protocols, response metrics, and kinetic parameters. Our findings indicate that positive feedback motifs where the stimulus enhances conversion reaction in the loop replicate the spacing effect across all response metrics, while feedforward motifs exhibit a metric-specific spacing effect. For some parameter combinations, linear cascades of activation and conversion reactions were found sufficient to qualitatively exhibit spacing effect characteristics.

The effect of duration between sessions on microperimetric biofeedback training in patients with maculopathies

Aim of this study was to explore the optimal training interval and times of microperimetric biofeedback training (MBFT) in maculopathies. Twenty-nine patients with maculopathies were divided into two groups: daily training (Group A) or alternate daily training (Group B). Both groups underwent 15 MBFT sessions. We compared the BCVA, reading speed, and fixation stability at baseline, after 5, 10, 15 sessions. After 15 sessions of MBFT, all visual parameters in both groups improved. There was a significant increase in BCVA after 5 sessions in both groups (P=0.016, and P<0.001 respectively), but Group A showed further improvement after 10 sessions (P<0.001). Regarding reading speed, Group A showed significant improvement from baseline after 15 sessions(P=0.020), Group B improved significantly after 5 sessions (P=0.047) and continued to improve after 10 sessions (P=0.030). Additionally, P1 and LgBCEA of Group A significantly improved after 10 sessions (P=0.001, and P=0.001 respectively), while Group B significantly improved after 5 sessions (P=0.002, and P<0.001 respectively). There was no significant difference in visual outcomes between the two groups (P>0.05) except LgBCEA (P=0.046) after 15 sessions. We concluded that the both MBFT frequencies are effective at improving vision and quality of life in patients with maculopathies. The alternate daily training group showed less time-dependent of improvement in all parameters and a greater benefit in fixation stability. Ten sessions are the optimal number of treatment sessions for alternate daily training.

A synapse-specific refractory period for plasticity at individual dendritic spines

How newly formed memories are preserved while brain plasticity is ongoing has been a source of debate. One idea is that synapses which experienced recent plasticity become resistant to further plasticity, a type of metaplasticity often referred to as saturation. Here, we probe the local dendritic mechanisms that limit plasticity at recently potentiated synapses. We show that recently potentiated individual synapses exhibit a synapse-specific refractory period for further potentiation. We further found that the refractory period is associated with reduced postsynaptic CaMKII signaling; however, stronger synaptic activation only partially restored the ability for further plasticity. Importantly, the refractory period is released after one hour, a timing that coincides with the enrichment of several postsynaptic proteins to pre-plasticity levels. Notably, increasing the level of the postsynaptic scaffolding protein, PSD95, but not of PSD93, overcomes the refractory period. Our results support a model in which potentiation at a single synapse is sufficient to initiate a synapse-specific refractory period that persists until key postsynaptic proteins regain their steady-state synaptic levels.

Benefits of spaced learning are predicted by re-encoding of past experience in ventromedial prefrontal cortex

More than a century of research shows that spaced learning improves long-term memory. Yet, there remains debate concerning why. A major limitation to resolving theoretical debates is the lack of evidence for how neural representations change as a function of spacing. Here, leveraging a massive-scale 7T human fMRI dataset, we tracked neural representations and behavioral expressions of memory as participants viewed thousands of natural scene images that repeated at lags ranging from seconds to many months. We show that spaced learning increases the similarity of human ventromedial prefrontal cortex representations across stimulus encounters and, critically, these increases parallel and predict the behavioral benefits of spacing. Additionally, we show that these spacing benefits critically depend on remembering and, in turn, 're-encoding' past experience. Collectively, our findings provide fundamental insight into how spaced learning influences neural representations and why spacing is beneficial.

Fostering Digital Life Skills Through Social Media With Adolescents in 6 German States: Protocol for an Accessibility Study According to the RE-AIM Framework

BACKGROUND

Social media is essential in the lives of adolescents, with 97% of US teenagers engaging daily. While it facilitates communication, learning, and identity development, it also poses risks like harmful content exposure and psychological distress, particularly for adolescents in their critical developmental stage. Teaching digital life skills innovatively counters these risks, adapting traditional competencies such as decision-making, problem-solving, creative and critical thinking, communication, interpersonal skills, self-awareness, empathy, and emotional and stress management to digital challenges.

OBJECTIVE

This study evaluates the accessibility of the "leduin" program, a novel intervention designed to impart digital life skills through Instagram. The program aims to leverage social media's educational potential, focusing on effective strategies to engage adolescents. Emphasizing accessibility is crucial, as it determines the program's overall impact.

METHODS

The leduin program, developed through intervention mapping, applies behavior change techniques via social media for 9th and 10th graders. It is a 14-week spaced learning curriculum with daily sessions <5 minutes. Emphasizing the "reach" aspect of the reach, effectiveness, adoption, implementation, and maintenance (RE-AIM) model, the recruitment targets diverse educational settings across 6 German states, aiming for inclusivity. Recruitment will involve schools, youth centers, and therapeutic facilities. The study seeks at least 128 participants, a calculated minimum to detect medium-sized effects in the quasi-experimental design and explore varying engagement levels and program responses. Data collection includes preintervention, postintervention, and 6-month follow-up surveys, using multilevel regression, latent growth models, and qualitative analysis to extensively assess reach and gain first insights on effectiveness, acceptance, implementation, and maintenance. The study aims to reveal key factors influencing program participation and interaction; a detailed analysis of engagement patterns will reveal the effectiveness of the recruitment strategies and barriers to participation. Additionally, initial indications of the program's impact on life skills, social media-related skills, health status, risk behaviors, and academic performance will be analyzed.

RESULTS

Recruitment was planned from May 2023 until the beginning of the leduin program in October 2023. As of March 2024, we have recruited 283 participants.

CONCLUSIONS

The leduin program stands as an innovative and essential initiative in adolescent health promotion, harnessing the power of social media to teach important digital life skills. This study highlights the critical role of accessibility in the success of social media interventions. Effective adolescent engagement strategies are imperative, as they dictate the overall impact of such interventions. The insights gained from this study will be instrumental in shaping future programs, laying groundwork for a subsequent, more comprehensive cluster-randomized controlled trial. The study's design acknowledges the limitations of the current quasi-experimental approach, including the anticipated sample size and the absence of a control group, and aims to provide a foundational understanding for future research in this field.

TRIAL REGISTRATION

Deutsches Register Klinischer Studien DRKS00032308; https://drks.de/search/de/trial/DRKS00032308.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/51085.

Dental students in an orthodontic course flipped classroom: A semi-experimental study on knowledge, practice, attitude, and satisfaction

OBJECTIVE

The purpose of this study was to determine the students' attitudes before and after the flipped classroom, and the effectiveness of this method to promote the students' lateral cephalograms tracing abilities, students' satisfaction and their final exam scores.

MATERIALS AND METHODS

This is a single-group quasi-experimental research conducted on dental students of Shiraz University of Medical Sciences (SUMS), Iran in 2019. The intervention was carried out in a blended learning approach with the flipped classroom model. Thirty-five fourth-year dental students participated in a flipped classroom held during a semester for the lateral cephalograms tracing course. The students were provided with the educational materials before the class time through multimedia learning tools and the class time was devoted to discussions. The students were asked to fill out four questionnaires (pretest/posttest attitudes, pretest/posttest self-assessments of theoretical knowledge and practical skills in cephalograms, posttest of satisfaction from quality of the course, and posttest of students' views about effectiveness of blended learning tools) and final exam scores of students.

RESULTS

Students' attitudes toward e-Learning were improved after the flipped classroom and the quality of this method was acceptable to the students (p < .001). Their self-assessment of theoretical knowledge and practical skills were promoted (p < .001). While all blended learning tools averaged more than the cut-off-point, short lecture (5.11 ± 0.98) and live feedback (4.98 ± 1.07) were considered to be the most efficient interactive tools.

CONCLUSION

It seems that the flipped classroom has a positive effect on increasing students' knowledge, attitude, and satisfaction. In general, this method of learning seems to be favored by dental students.

CLINICAL SIGNIFICANCE

The findings showed that blended learning had a positive effect on increasing knowledge, performance, and satisfaction among dental students. Therefore, blended learning as a reliable method might be used in training dental students.

Accelerated Theta Burst Stimulation: Safety, Efficacy, and Future Advancements

Theta burst stimulation (TBS) is a noninvasive brain stimulation technique that can be used to modulate neural networks underlying psychiatric and neurological disorders. TBS can be delivered intermittently or continuously. The conventional intermittent TBS protocol is approved by the U.S. Food and Drug Administration to treat otherwise treatment-resistant depression, but the 6-week duration limits the applicability of this therapy. Accelerated TBS protocols present an opportunity to deliver higher pulse doses in shorter periods of time, thus resulting in faster and potentially more clinically effective treatment. However, the acceleration of TBS delivery raises questions regarding the relative safety, efficacy, and durability compared with conventional TBS protocols. In this review paper, we present the data from accelerated TBS trials to date that support the safety and effectiveness of accelerated protocols while acknowledging the need for more durability data. We discuss the stimulation parameters that seem to be important for the efficacy of accelerated TBS protocols and possible avenues for further optimization.

Effects of accelerated intermittent theta-burst stimulation in modulating brain of Alzheimer's disease

Intermittent theta-burst stimulation (iTBS) is emerging as a noninvasive therapeutic strategy for Alzheimer's disease (AD). Recent advances highlighted a new accelerated iTBS (aiTBS) protocol, consisting of multiple sessions per day and higher overall pulse doses, in brain modulation. To examine the possibility of applying the aiTBS in treating AD patients, we enrolled 45 patients in AD at early clinical stages, and they were randomly assigned to either receive real or sham aiTBS. Neuropsychological scores were evaluated before and after treatment. Moreover, we detected cortical excitability and oscillatory activity changes in AD, by the single-pulse TMS in combination with EEG (TMS-EEG). Real stimulation showed markedly better performances in the group average of Auditory Verbal Learning Test scores compared to baseline. TMS-EEG revealed that aiTBS has reinforced this memory-related cortical mechanism by increasing cortical excitability and beta oscillatory activity underlying TMS target. We also found an enhancement of local natural frequency after aiTBS treatment. The novel findings implicated that high-dose aiTBS targeting left DLPFC is rapid-acting, safe, and tolerable in AD patients. Furthermore, TMS-related increase of specific neural oscillation elucidates the mechanisms of the AD cognitive impairment ameliorated by aiTBS.

ERRα regulates synaptic transmission through reactive oxygen species in hippocampal neurons

Reactive oxygen species (ROS) play multiple roles in synaptic transmission, and estrogen-related receptor α (ERRα) is involved in regulating ROS production. The purpose of our study was to explore the underlying effect of ERRα on ROS production, neurite formation and synaptic transmission. Our results revealed that knocking down ERRα expression affected the formation of neuronal neurites and dendritic spines, which are the basic structures of synaptic transmission and play important roles in learning, memory and neuronal plasticity; moreover, the amplitude and frequency of miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) were decreased. These abnormalities were reversed by overexpression of human ERRα. Additionally, we also found that knocking down ERRα expression increased intracellular ROS levels in neurons. ROS inhibitor PBN rescued the changes in neurite formation and synaptic transmission induced by ERRα knockdown. These results indicate a new possible cellular mechanism by which ERRα affects intracellular ROS levels, which in turn regulate neurite and dendritic spine formation and synaptic transmission.

A randomized sham-controlled trial of high-dosage accelerated intermittent theta burst rTMS in major depression: study protocol

BACKGROUND

Intermittent theta burst stimulation (iTBS), a novel form of repetitive transcranial magnetic stimulation (rTMS), can be administered in 1/10th of the time of standard rTMS (~ 3 min vs. 37.5 min) yet achieves similar outcomes in depression. The brief nature of the iTBS protocol allows for the administration of multiple iTBS sessions per day, thus reducing the overall course length to days rather than weeks. This study aims to compare the efficacy and tolerability of active versus sham iTBS using an accelerated regimen in patients with treatment-resistant depression (TRD). As a secondary objective, we aim to assess the safety, tolerability, and treatment response to open-label low-frequency right-sided (1 Hz) stimulation using an accelerated regimen in those who do not respond to the initial week of treatment.

METHODS

Over three years, approximately 230 outpatients at the Centre for Addiction and Mental Health and University of British Columbia Hospital, meeting diagnostic criteria for unipolar MDD, will be recruited and randomized to a triple blind sham-controlled trial. Patients will receive five consecutive days of active or sham iTBS, administered eight times daily at 1-hour intervals, with each session delivering 600 pulses of iTBS. Those who have not achieved response by the week four follow-up visit will be offered a second course of treatment, regardless of whether they initially received active or sham stimulation.

DISCUSSION

Broader implementation of conventional iTBS is limited by the logistical demands of the current standard course consisting of 4-6 weeks of daily treatment. If our proposed accelerated iTBS protocol enables patients to achieve remission more rapidly, this would offer major benefits in terms of cost and capacity as well as the time required to achieve clinical response.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04255784.

Enhancing Associative Learning in Rats With a Computationally Designed Training Protocol

Background

Learning requires the activation of protein kinases with distinct temporal dynamics. In Aplysia, nonassociative learning can be enhanced by a computationally designed learning protocol with intertrial intervals (ITIs) that maximize the interaction between fast-activated PKA (protein kinase A) and slow-activated ERK (extracellular signal-regulated kinase). Whether a similar strategy can enhance associative learning in mammals is unknown.

Methods

We simulated 1000 training protocols with varying ITIs to predict an optimal protocol based on empirical data for PKA and ERK dynamics in rat hippocampus. Adult male rats received the optimal protocol or control protocols in auditory fear conditioning and fear extinction experiments. Immunohistochemistry was performed to evaluate pCREB (phosphorylated cAMP response element binding)\protein levels in brain regions that have been implicated in fear acquisition.

Results

Rats exposed to the optimal conditioning protocol with irregular ITIs exhibited impaired extinction memory acquisition within the session using a standard footshock intensity, and stronger fear memory retrieval and spontaneous recovery with a weaker footshock intensity, compared with rats that received massed or spaced conditioning protocols with fixed ITIs. Rats exposed to the optimal extinction protocol displayed improved extinction of contextual fear memory and reduced spontaneous recovery compared with rats that received standard extinction protocols. Moreover, the optimal conditioning protocol increased pCREB levels in the dentate gyrus of the dorsal hippocampus, suggesting enhanced induction of long-term potentiation.

Conclusions

These findings demonstrate that a computational model-driven behavioral intervention can enhance associative learning in mammals and may provide insight into strategies to improve cognition in humans.

Progress Testing in UK Medical Education: Evaluating Its Impact and Potential

This comprehensive review critically examines the UK medical curriculum, with a particular focus on progress testing as an innovative assessment strategy. The curriculum, evolving from foundational sciences to practical applications, is encapsulated in the integrated curriculum model (ICM). This model adeptly combines theoretical knowledge with clinical practice, fostering cognitive, affective, and psychomotor skills among medical students. Central to this review is an exploration of progress testing. This method, grounded in constructivist learning theories, emphasises continuous assessment and professional development. Progress testing's regular, comprehensive examinations are instrumental in guiding students through the progressive stages of competence, as outlined in Miller's pyramid, from foundational knowledge to clinical proficiency. The review also addresses the broader impacts of progress testing on teaching approaches, student feedback, academic and pastoral support, and quality assurance. By aligning with the dynamic requirements of 21st-century medical training, progress testing not only nurtures well-rounded professionals but also ensures compliance with regulatory bodies like the General Medical Council. Its emphasis on continuous evaluation aligns with the practical realities of a medical career, driving curricular innovation and aligning with regulatory standards. The implementation of progress testing marks a significant advancement in medical education. Its continuous, holistic nature benefits both students and educators, nurturing a more engaged learning attitude and meeting evolving medical needs. The adoption of this assessment strategy is seen as pivotal in shaping competent medical professionals, ready to face the challenges of modern medical practice.

Do age and language impairment affect speed of recognition for words with high and low closeness centrality within the phonological network?

PURPOSE

Speed and accuracy of lexical access change with healthy ageing and neurodegeneration. While a word's immediate phonological neighbourhood density (i.e. words differing by a single phoneme) influences access, connectivity to all words in the phonological network (i.e. closeness centrality) may influence processing. This study aimed to investigate the effect of closeness centrality on speed and accuracy of lexical processing pre- and post- a single word-training session in healthy younger and older adults, and adults with logopenic primary progressive aphasia (lvPPA), which affects phonological processing.

METHOD

Participants included 29 young and 17 older healthy controls, and 10 adults with lvPPA. Participants received one session of word-training on words with high or low closeness centrality, using a picture-word verification task. Changes in lexical decision reaction times (RT) and accuracy were measured.

RESULT

Baseline RT was unaffected by age and accuracy was at ceiling for controls. Post-training, only young adults' RT were significantly faster. Adults with lvPPA were slower and less accurate than controls at baseline, with no training effect. Closeness centrality did not influence performance.

CONCLUSION

Absence of training effect for older adults suggests higher threshold to induce priming, possibly associated with insufficient dosage or fatigue. Implications for word-finding interventions with older adults are discussed.

The influence of learning history on anterograde interference

Classically interpreted as a competition between opposite memories (A vs B), anterograde interference (AI) also emerges in the absence of competing memories (A vs A), suggesting that mechanisms other than those involved in memory competition contribute to AI. To investigate this, we tested the hypothesis that extending motor practice would enhance a first memory, but come at the cost of reduced learning capabilities when subsequently exposed to a second learning session of the same task. Based on converging biological evidence, AI was expected to depend upon the degree of extended practice of the initial exposure. During a first Session, four conditions were carried out where participants (n = 24) adapted to a gradually introduced -20° visual deviation while the extent of the initial exposure was manipulated by varying the duration or type of the performance asymptote. Specifically, the performance asymptote at -20° was either Short (40 trials), Moderate (160 trials), Long (320 trials), or absent due to continuously changing perturbations around the mean of -20° (Jagged; 160 trials). After a 2-min interval, participants re-adapted to the same (-20°) visual deviation, which was meant to probe the effect of extended practice in the first Session on the learning capabilities of a second identical memory (A vs A). The results first confirmed that the duration of exposure in the first Session enhanced immediate aftereffects in the Moderate, Long, and Jagged conditions as compared to the Short condition, suggesting that extended practice enhanced retention of the first memory. When comparing the second Session to the first one, results revealed a different pattern of re-adaptation depending on the duration of initial exposure: in the Short condition, there was evidence for facilitated re-adaptation and similar aftereffects. However, in the Moderate, Long and Jagged conditions, re-adaptation was similar and aftereffects were impaired, suggestive of AI. This suggests that extended practice initially enhances memory formation, but comes at the cost of reduced subsequent learning capabilities. One possibility is that AI occurs because extended practice induces the emergence of network-specific homeostatic constraints, which limit subsequent neuroplastic and learning capabilities in the same neural network.

Development and evaluation of a pre-clerkship spiral curriculum: data from three medical school classes

Pre-clerkship curricula of most Liaison Committee on Medical Education (LCME)-accredited medical schools are divided into blocks by organ system, leaving a significant amount of information susceptible to loss due to prolonged nonuse. We describe the implementation of a formal Spiral Curriculum that periodically revisits material from previous blocks. Learners were surveyed on receptivity to the curriculum across three graduating classes at a single medical school. Medical school graduate classes of 2020, 2021, and 2022 were surveyed at the end of their pre-clerkship years (2018-2020). The class of 2022 actually received the Spiraled Curriculum intervention, for which the authors created 500 board exam style multiple-choice questions, periodically administered via mandatory in-class sessions ranging from 10 to 20 questions reviewing content from previous blocks with designated expert faculty. Response rates were 36% (n = 46), 45% (n = 52), and 32% (n = 40) for classes of 2020, 2021, and 2022, respectively. On a Likert scale (1 = strongly disagree, 5 = neutral, 10 = strongly agree), the classes of 2020, 2021, and 2022 provided statistically significant differences in their belief that a Spiraled Curriculum would/did help them retain information as 8.2 (SD 1.7), 8.2 (SD 2.2), and 5.0 (SD 3.0) (n < 0.05). All classes endorsed neutral confidence in the existing pre-clerkship curriculum in themselves to prepare for United Stated Medical Licensing Examination (USMLE) Step 1, and in their retention of previous block material with no statistically significant differences between classes. USMLE Step 1 scores did not differ significantly between classes (n = 0.21). Those who did not receive the Spiral Curriculum were highly receptive to it in theory, while those who actually received the intervention gave a neutral rating. Per survey comments, implementation of a Spiraling Curriculum would ideally be administered as either team-based or self-directed activities, and a Spiraling Curriculum may be difficult to implement in accelerated (18 month) pre-clerkship formats.Practice points Question: What is the receptivity of medical students to a formal Spiral curriculum that uses time-spaced repetition sessions of board exam style questions to revisit previous block content of their pre-clerkship years?Findings: In this single-center, quasi-experimental study, the two control group medical school classes had very positive theoretical reception to a Spiral curriculum proposal (rated 8 out of 10) while the class who actually received the Spiral curriculum provided a statistically significant lower neutral rating (rated 5 out of 10), citing preference for a team-based or self-directed format.Meaning: Medical students are strongly in favor of structured time-spaced repetition with board exam style questions to revisit previous material but prefer a format that does not interfere with time to personalize their medical school experience.

Improving physiotherapy students' anatomy learning experience and short-term knowledge retention-An observational study in Malta

Anatomy is physiotherapy's foundation. However, undergraduate classroom learning and knowledge acquisition-retention remain questionable. This study explored the possibility of improving this learning experience and evaluates the gross anatomy of abdomen and pelvis short-term knowledge retention among first-year physiotherapy students in Malta. The online Kahoot! game-based quiz platform was used through an instructor-designed best-of-four multiple-choice questions. Correctly answered questions and Kahoot! scores generated by the platform were utilized to measure knowledge retention. Kahoot! sessions 1 and 3 shared similar attendance and response rate and were compared together. The Mann-Whitney U test was used to compare Kahoot! scores and Chi test for trend to compare correctly answered questions. Students' perceived learning experiences before and after the introduction of the Kahoot quizzes were gathered through Likert scores and analyzed using McNamar's chi-square test. Overall, a significantly increased trend in correctly answered questions (χ2 : 23.38, p-value: <0.001) across the Kahoot! sessions were evident. Four questions out of 12 exhibited significant Kahoot! scores differences. Students reported better learning experiences following the initiation of Kahoot! (χ2 : 5.1, p-value: 0.02). Indeed, all students agreed that the use of the interactive quiz improved their anatomy short term knowledge retention. Introducing an online interactive quiz as part of the lecture program may be useful to improve the learning experience and anatomy knowledge retention among physiotherapy students.

Neurocognitive Model of Schema-Congruent and -Incongruent Learning in Clinical Disorders: Application to Social Anxiety and Beyond

Negative schemas lie at the core of many common and debilitating mental disorders. Thus, intervention scientists and clinicians have long recognized the importance of designing effective interventions that target schema change. Here, we suggest that the optimal development and administration of such interventions can benefit from a framework outlining how schema change occurs in the brain. Guided by basic neuroscientific findings, we provide a memory-based neurocognitive framework for conceptualizing how schemas emerge and change over time and how they can be modified during psychological treatment of clinical disorders. We highlight the critical roles of the hippocampus, ventromedial prefrontal cortex, amygdala, and posterior neocortex in directing schema-congruent and -incongruent learning (SCIL) in the interactive neural network that comprises the autobiographical memory system. We then use this framework, which we call the SCIL model, to derive new insights about the optimal design features of clinical interventions that aim to strengthen or weaken schema-based knowledge through the core processes of episodic mental simulation and prediction error. Finally, we examine clinical applications of the SCIL model to schema-change interventions in psychotherapy and provide cognitive-behavior therapy for social anxiety disorder as an illustrative example.

Emerging Roles for DNA 6mA and RNA m6A Methylation in Mammalian Genome

Epigenetic methylation has been shown to play an important role in transcriptional regulation and disease pathogenesis. Recent advancements in detection techniques have identified DNA N6-methyldeoxyadenosine (6mA) and RNA N6-methyladenosine (m6A) as methylation modifications at the sixth position of adenine in DNA and RNA, respectively. While the distributions and functions of 6mA and m6A have been extensively studied in prokaryotes, their roles in the mammalian brain, where they are enriched, are still not fully understood. In this review, we provide a comprehensive summary of the current research progress on 6mA and m6A, as well as their associated writers, erasers, and readers at both DNA and RNA levels. Specifically, we focus on the potential roles of 6mA and m6A in the fundamental biological pathways of the mammalian genome and highlight the significant regulatory functions of 6mA in neurodegenerative diseases.

Locating causal hubs of memory consolidation in spontaneous brain network in male mice

Memory consolidation after learning involves spontaneous, brain-wide network reorganization during rest and sleep, but how this is achieved is still poorly understood. Current theory suggests that the hippocampus is pivotal for this reshaping of connectivity. Using fMRI in male mice, we identify that a different set of spontaneous networks and their hubs are instrumental in consolidating memory during post-learning rest. We found that two types of spatial memory training invoke distinct functional connections, but that a network of the sensory cortex and subcortical areas is common for both tasks. Furthermore, learning increased brain-wide network integration, with the prefrontal, striatal and thalamic areas being influential for this network-level reconfiguration. Chemogenetic suppression of each hub identified after learning resulted in retrograde amnesia, confirming the behavioral significance. These results demonstrate the causal and functional roles of resting-state network hubs in memory consolidation and suggest that a distributed network beyond the hippocampus subserves this process.

Virtual spaced-learning method, during COVID-19 for Pharm D students

BACKGROUND

The coronavirus (COVID-19) outbreak basically changed teaching methods across the world, and learning was almost replaced by virtual learning during the pandemic. Also, the spacing effect is one of the most well-established phenomena in the science of learning. Using temporal intervals for re-exposing learners to information over time (spaced learning) leads to more effective retention of knowledge compared to having information presented at a single time (massed learning). Hence, we designed a virtual spaced learning method to reap the benefits of virtual learning and spaced learning concomitantly.

METHODS/APPROACH

An interventional semi- experimental survey among 66 Pharm D students was designed and implemented. Students were divided into two groups (spaced vs mass learning) in the national integrated virtual education platform (NAVID) as the matrix for teaching as well as evaluation. Classes were conducted in the following sequence: 1- answering the pre-test, 2- watching and listening to the educational content (separately for each group), 3- answering the post-test (n = 1). The pre/post-test consisted of 10 four-choice questions based on the Kirkpatrick Model extracted from the educational content.

RESULTS/OUTCOMES

Findings revealed that the average score was not significantly different between the post-tests of the spaced learning and mass learning (7.26 ± 2.26 vs 6.5 ± 2.5) methods utilizing the independent t- test (p ≥ 0.05).

CONCLUSIONS

Since no statistically significant improvement was observed in the virtual spaced learning group compared to the control group, it seems that clarifying the significant influence of the spaced learning strategy in pharmacy education requires longer period of study, or study on less complex or skill-based topics for further evaluation.

A behavioral tagging account of kinase contribution to memory formation after spaced aversive training

Long-term memory (LTM) can be induced by repeated spaced training trials. Using the weak inhibitory avoidance (wIA) task, we showed that one wIA session does not lead to a 24-h LTM, whereas two identical wIA sessions spaced by 15 min to 6 h induce a 24-h LTM. This LTM promotion depends both on hippocampal protein synthesis and the activity of several kinases. In agreement with the behavioral tagging (BT) hypothesis, our results suggest that the two training sessions induce transient learning tags and lead, via a cooperative effect, to the synthesis of plasticity-related proteins (PRPs) that become available and captured by the tag from the second session. Although ERKs1/2 are needed for PRPs synthesis and CaMKs are required for tag setting, PKA participates in both processes. We conclude that the BT mechanism accounts for the molecular constraints underlying the classic effect of spaced learning on LTM formation.