A fair reward ensures a good memory

June 17, 2020

How does our memory work and how can we optimize its mechanisms on a daily basis? This question is at the heart of many neuroscience research projects. Among the brain structures examined to better understand memory mechanisms, the reward system is now at the centre of investigations. Through the examination of brain activity in healthy human subjects, scientists from the University of Geneva (UNIGE) have highlighted the lasting positive effect of a reward - monetary, in this case - on the ability of individuals to retain a variety of information. Moreover, and much more surprisingly, the research team demonstrated that the average accumulation of reward should be neither too small nor too large. By ensuring an effective neural dialogue between the reward circuit and the memory circuit, this delicate balance allows the proper encoding of memories in our brain. These results can be read in Nature Communications.

Empirically, it seems quite logical that obtaining a reward can improve the memories associated with it. But what are the brain mechanisms at work, and how can we exploit them to optimize our memory capacity? "The positive influence of a reward on memory is a well-known phenomenon," says Sophie Schwartz, full professor in the Department of Basic Neurosciences at the UNIGE Faculty of Medicine, who led this work. "However, our experiment aimed to take a further step in understanding this mechanism by looking at two important aspects: does the effect last over time and what role does the accumulation of reward play?"

A measured challenge to motivate the brain

To answer these questions, the scientists have developed an experiment using functional magnetic resonance imaging, an imaging technique that allows real-time observation of the brain in action. About 30 healthy subjects were asked to remember associations between objects and people; each correct answer was associated with points gained, and each incorrect answer with points lost (the points were then converted into money). Twenty minutes later, the subjects were asked to retrieve these associations to earn additional points. Critically, the average number of points that could be gained varied over the course of the experiment.

"Contrary to what one might have thought, the best results were not associated with the highest accumulation of rewards, the point where subjects should have been the most motivated", says Kristoffer Aberg, a researcher now at the Weizmann Institute of Science and the first author of this work. The most effective? Somewhere between the highest and lowest accumulated rewards. "Our brain needs rewards to motivate us, but also challenges", explains Sophie Schwartz. "If the task is too easy, motivation decreases as quickly as if it is too difficult, and that affects our ability to encode information. Imagine picking berries in the forest: if they are everywhere, you do not have to remember where to find them. If there are only a few, the effort required to pick them is too great in relation to the possible gain - a few berries will not feed us. Now, if clusters of berries are scattered throughout the forest, remembering their exact location will allow us to pick more in a short time."

A dialogue between brain areas

In the brain, memory is primarily managed by the hippocampus, a region of the brain responsible for encoding and storing memories. When a reward is involved, however, another region is activated, the ventral tegmental area, which is involved in the reward system and responsible for the release of dopamine related to the satisfaction of obtaining a reward. "It is the dialogue between these two brain areas that helps maintain motivation, improve learning, and consolidate memories, even over time," explains Kristoffer Aberg.

This experiment shows the importance of motivation in memory and learning, but also the subtle, and probably individual-specific, balance that should be instituted. These lessons are particularly useful in the school environment, with the idea of creating learning contexts that would foster this motivation according to the needs of children.
-end-


Université de Genève

Related Memory Articles from Brightsurf:

Memory of the Venus flytrap
In a study to be published in Nature Plants, a graduate student Mr.

Memory protein
When UC Santa Barbara materials scientist Omar Saleh and graduate student Ian Morgan sought to understand the mechanical behaviors of disordered proteins in the lab, they expected that after being stretched, one particular model protein would snap back instantaneously, like a rubber band.

Previously claimed memory boosting font 'Sans Forgetica' does not actually boost memory
It was previously claimed that the font Sans Forgetica could enhance people's memory for information, however researchers from the University of Warwick and the University of Waikato, New Zealand, have found after carrying out numerous experiments that the font does not enhance memory.

Memory boost with just one look
HRL Laboratories, LLC, researchers have published results showing that targeted transcranial electrical stimulation during slow-wave sleep can improve metamemories of specific episodes by 20% after only one viewing of the episode, compared to controls.

VR is not suited to visual memory?!
Toyohashi university of technology researcher and a research team at Tokyo Denki University have found that virtual reality (VR) may interfere with visual memory.

The genetic signature of memory
Despite their importance in memory, the human cortex and subcortex display a distinct collection of 'gene signatures.' The work recently published in eNeuro increases our understanding of how the brain creates memories and identifies potential genes for further investigation.

How long does memory last? For shape memory alloys, the longer the better
Scientists captured live action details of the phase transitions of shape memory alloys, giving them a better idea how to improve their properties for applications.

A NEAT discovery about memory
UAB researchers say over expression of NEAT1, an noncoding RNA, appears to diminish the ability of older brains to form memories.

Molecular memory can be used to increase the memory capacity of hard disks
Researchers at the University of Jyväskylä have taken part in an international British-Finnish-Chinese collaboration where the first molecule capable of remembering the direction of a magnetic above liquid nitrogen temperatures has been prepared and characterized.

Memory transferred between snails
Memories can be transferred between organisms by extracting ribonucleic acid (RNA) from a trained animal and injecting it into an untrained animal, as demonstrated in a study of sea snails published in eNeuro.

Read More: Memory News and Memory Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.