Beyond memory, learning to learn

There are countless studies of the neurobiology of memory, how neurons store the information gained from experience so it can be recalled. But as any educator knows, merely recollecting the information we learn in school is hardly the point of an education. Neither is recollection the point of cognitive behavioral therapy or meditation, all of which can enable better assessment, perception and learning of information that has not yet been experienced. Brains don’t merely store memories of the information in experience, rather with the right mental training, we can also “learn to learn.” Learning to learn makes us more adaptive, mindful, and intelligent, but rather little is known about the underlying neurobiology.

In work led by Ain for her Ph.D. thesis, we discovered that a few hours of cognitive control training causes learning to learn in mice, and that learning to learn is accompanied by tuning a key brain circuit for memory, so that it becomes persistently more effective at suppressing noisy inputs and more persistently effective at enhancing the most currently salient inputs. These changes result from the tuning of a network of excitatory and inhibitory synapses in the medial entorhinal cortex to hippocampus neural circuit that is crucial for episodic memory and spatial information processing.

These neural circuit enhancements do not arise just from ordinary learning, they arise from training to ignore distraction while learning. Such cognitive control training to judiciously process useful information while explicitly ignoring distracting information, is fundamental to the cognitive behavioral therapy that therapists practice with their patients, and a skill that meditation practices train.

The photomicrograph is an immunohistochemical image of the granule cell and hilar regions of the mouse dentate gyrus in which memory-activated cells were tagged to permanently express a green protein. The red dots mark the presence of PKMz, a protein that is crucial for the maintained strengthening of neural synapses and the persistent storage of the memory. The overlap of the two proteins (yellow) identifies the physical, neurobiological locations of memory storage and improved information processing that results in learning to learn. The schematic hands are in the gesture of focus, directed at an exemplary image of a memory (Thích Quảng Đức) that, beyond its recollection, has also transformed future opinion and understanding.