Priming is a phenomenon that exploits the brain’s reliance on association to cement memories by evoking predetermined or expected responses based on slanted questions or exposures. For example, when asked “What do cows drink?” many people immediately respond “milk” rather than “water”, because the word “cows” evokes the affiliations they associate with it, of which milk is one. Neurons build associations by forming synaptic connections that become co-activated when one of the linked neurons experiences an action potential. By linking neurons through co-activation, neurons can build associations and mental relationships between previously unrelated concepts. Association is one of the fundamental principles of memory, to force us to familiarize ourselves with expected consequences and events and learn to prepare accordingly. In this case, the neuron that encodes our conceptualization of cows is linked to the neuron that “represents” milk, so when our cow neuron is activated, so is the neuron that represents milk. Therefore, our initial response when we are asked “What do cows drink?” is often “milk”, because the synaptic connections that link our cow neuron and our milk neuron (or more likely, neurons) are stronger or even more present than the synaptic connections that link our cow neurons and our water neurons.
It’s important to note though, that despite the significant and mostly unconscious role that priming plays is our everyday lives, our conscious will can often override the effects of priming. Most people realize that “milk” is an incorrect response, even without prompting. They can then override their instinctive response and give a more measured, conscious response. Building associations that we can draw upon instantly and subconsciously is critical; we don’t want to be bogged down by comparatively slow, analytical calculations when faced with situations that need only rely on fast-thinking associations, like that between predators and danger. But sometimes our associations are no longer applicable, or they are too generalized, so our brain has also evolved to allow us to engage “manual mode” and reason about some of our innate selections to ensure that our “automatic mode” is acting optimally. However, because most priming is unconscious, many people do not realize that they are being constantly influenced by memory associations and so do not have the conscious capacity to engage manual mode and critically reflect on their actions.