Brain network structure in developmental learning disorders
Learning-related developmental disorders affect many children, but we still do not have a good grasp of the brain changes underlying these conditions.
This study showed that one difference between children with and without diagnosed learning difficulties – such as autism spectrum disorder, dyslexia and attention deficit hyperactivity disorder – lies in the organisation of their brain networks. Using a special MRI technique to reveal the brain’s communication highways, the researchers showed that the brain networks of children with learning difficulties did not organise into highly connected “hubs” to the same extent as the brains of other children. The many incoming and outgoing connections of these hubs make them similar to highly trafficked airports, helping neural information to move more efficiently between any two brain regions.
Siugzdaite et al. (2020) Transdiagnostic brain mapping in developmental disorders. Current Biology DOI:
Artificially strengthening local memories during sleep
Memory consolidation occurs during sleep, and it is possible to artificially help this process. In an approach termed targeted memory reactivation (TMR), experimenters use external cues to help strengthen memories during sleep.
In this study, researchers tested whether TMR acted globally – through the whole brain – or more locally. They created a memory task that relied heavily on just one brain hemisphere. When the memory was triggered during sleep by presenting an external cue (a memory-linked odor) to the same brain hemisphere, it improved memory recall. It also changed the nature of local – rather than global – brain network activity during sleep. The study shows that targeted memory reactivation can specifically enhance memories that rely heavily on a single brain hemisphere.
Bar et al. (2020) Local targeted memory reactivation in human sleep. Current Biology DOI: https://doi.org/10.1016/j.cub.2020.01.091
Tips for Teacher-Researcher collaboration
The interdisciplinary, practical orientation of the science of learning has brought numerous challenges. These include the use of different terminologies, different research approaches, and the difficulty of converting laboratory-based research into interventions that can withstand the natural classroom environment. What is the best way to overcome these issues?
In this case study aimed at reducing classroom noise in primary schools, the authors conclude that ground-up collaboration is vital. Teachers and researchers should co-design interventions, ensuring they are scientifically rigorous yet remain practical in the classroom. The authors also stress a need to engage with people throughout the education hierarchy (including children, parents, teachers, principals and school administrators), and to understand the school’s perspective on the purpose of the intervention.
Massonnié et al. (2020) Scientific collaboration with educators: practical insights from an in-class noise-reduction intervention. Mind, Brain and Education DOI: https://doi.org/10.1111/mbe.12...
Human memory retrieval involves replay of brain activity patterns
When we retrieve a memory, we replay the event or experience in our mind. This should involve replay of brain activity patterns, or neuronal spike sequences, corresponding to the event. Although such replay has not been shown in humans, a similar replay phenomenon has been shown in animals during sleep-based memory consolidation.
In this study, as human subjects undergoing epilepsy surgery encoded a memory, repetitive, short bursts of spike sequences occurred. Similar sequences occurred when they later recalled the memory, indicating memory-induced replay of spike activity. Interestingly, the bursts of activity during recall became progressively more similar to what was seen during encoding, right up until the person vocalised their response. This study shows that human memory recall involves replaying the specific, orderly patterns of activity that occur during the original experience.
Vaz et al. (2020) Replay of cortical spiking sequences during human memory retrieval. Science 367 (6482): 1131-1134 DOI: