The 1880 study of the psychologist Hermann Ebbinghaus replicated in recent research: the importance of making connections between different knowledge.
Neurobiologists Blake Richards and Paul Frankland challenge the prevailing view of memory, which holds that forgetting is a process of loss: the gradual washing away of critical information despite our best efforts to retain it.
According to Richards and Frankland, the goal of memory is not only to accurately store information, but also to ‘optimize decision-making’ in chaotic environments that change rapidly. In this model of cognition, forgetting is an evolutionary strategy , a useful process that runs in the background of memory, evaluating and discarding information that does not promote the survival of the species.
We often think of memories as books in a library, archived and accessed when needed. But in reality they are more like cobwebs , threads of memory distributed in millions of connected neurons. When we learn something new, when a teacher delivers a new lesson to a student, for example, the material is encoded through these neural networks, turning the experience into a memory. Each memory, too, influences the rest, so our passing is actually a reconstruction of our brain, which is why it is so easy to deceive ourselves :
Forgetting is almost immediately the nemesis of memory, as the psychologist Hermann Ebbinghaus discovered in the 1880s. Ebbinghaus pioneered historical research in the field of retention and learning, observing what he called the forgetting curve, a measure of how much we forget over time. In his experiments, he found that without any reinforcement or connection to prior knowledge, information is quickly forgotten: about 56 percent in one hour, 66 percent after one day, and 75 percent after six days.
So what can be done to preserve the hard work of teaching? After all, evolutionary imperatives, which weed out our memories of strange information, don’t always perfectly align with the requirements of the curriculum or the demands of the information age. In other words, learning the multiplication tables is no use escaping lions, but in the modern world that knowledge has proven more than courageous .
The Persistence of Memory
The same neural circuitry seems to be involved in forgetting and remembering. MIT neuroscientists, led by Richard Cho , explain the mechanisms for synaptic strengthening in a 2015 study , also publishing their findings in Neuron . When neurons fire frequently, synaptic connections are strengthened; the opposite is true for neurons that rarely fire.
Known as synaptic plasticity , this phenomenon explains why some memories persist while others fade. Repeatedly accessing a stored but faded memory, such as a rule of geometry or a crucial historical fact, rekindles the neural network that contains the memory and encodes it more deeply.
Researchers have also learned that not all new memories are the same. For example, here are two sets of letters to remember:
The second set of letters is more memorable: the more connections neurons have with other neurons, the stronger the memory. The seven letters in NPFXOSK seem random and disjointed, while ORANES benefits from its existing , deeply coded linguistic context . The word "oranges too" invokes sensory memory, from the image of an orange to its smell, and perhaps even evokes other memories of oranges in your kitchen or growing on a tree.
That is, you remember by placing new memories on the crumbling foundations of older ones.