Switching on one-shot learning in the brain

May 11, 2015

Credit: Sang Wan Lee/Caltech

By Science Daily

Most of the time, we learn only gradually, incrementally building connections between actions or events and outcomes. But there are exceptions–every once in a while, something happens and we immediately learn to associate that stimulus with a result. For example, maybe you have had bad service at a store once and sworn that you will never shop there again.

This type of one-shot learning is more than handy when it comes to survival–think of an animal quickly learning to avoid a type of poisonous berry. In that case, jumping to the conclusion that the fruit was to blame for a bout of illness might help the animal steer clear of the same danger in the future. On the other hand, quickly drawing connections despite a lack of evidence can also lead to misattributions and superstitions; for example, you might blame a new food you tried for an illness when in fact it was harmless, or you might begin to believe that if you do not eat your usual meal, you will get sick.

Scientists have long suspected that one-shot learning involves a different brain system than gradual learning, but could not explain what triggers this rapid learning or how the brain decides which mode to use at any one time.

Now Caltech scientists have discovered that uncertainty in terms of the causal relationship–whether an outcome is actually caused by a particular stimulus–is the main factor in determining whether or not rapid learning occurs. They say that the more uncertainty there is about the causal relationship, the more likely it is that one-shot learning will take place. When that uncertainty is high, they suggest, you need to be more focused in order to learn the relationship between stimulus and outcome.

7 comments on “Switching on one-shot learning in the brain

  • I don’t understand these findings. Are they saying the less evidence for a certain idea, the more likely it is to be believed? The more uncertainty about something, the more likely we will be to jump to a conclusion?



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  • But this questionable association can create two (at least) sorts of memories. The memory of an association (this is how it goes folks…cue superstitious chicken) or the memory of an hypothesis of an association (cue the vigilante scientist looking for confirmation or a disproof).



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  • They say that the more uncertainty there is about the causal relationship, the more likely it is that one-shot learning will take place.

    Surely that is a typo



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  • Surely that is a typo

    I don’t think so.

    The big question is…..are we remembering a relationship or are we remembering a potential relationship that needs further resolution? The latter has more attributes, the relationship and its associate problems. Often adding material to things increases their memorability, but in this case we also may have an increase in associate saliency because we are put on our guard to notice other instances of such relationships so that we can settle the issue and set it to one side. Nagging facts stay in the front of the mind better than banal, resolved facts.

    This may be the basis of why we are scientists.



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  • It seems to me that there must be a LOT more to figure out. The alleged inverse relationship between the rapidness of learning and the uncertainty of causation, must surely have tight limits? At one end, when a casual relationship is blindingly obvious – put your hand in a fire, and it’s sore, I can’t imagine that would be learnt slowly. At the other end, I can’t imagine very tenuous, barely detectable links between cause and effect being learned rapidly, if at all! What happened to Skinner and his pigeons?



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