Memory in the Brain
The Cerebellum: Implicit and Procedural Memory
The cerebellum, located at the back of the brain, plays a key role in:
- Procedural memories (how to ride a bike, type, or play piano)
- Motor learning
- Classical conditioning
A well-known line of research demonstrates this clearly. In a classical conditioning experiment, rabbits learned to blink when a tone predicted a puff of air to the eye. When researchers damaged the rabbits’ cerebellum, the animals could no longer learn the conditioned eye-blink response (Steinmetz, 1999; Green & Woodruff-Pak, 2000). This tells us the cerebellum is necessary for forming certain types of learned, automatic behaviors—even when the hippocampus is not involved.
The Prefrontal Cortex: Organizing, Encoding, and Retrieving Information
While the cerebellum handles implicit learning, the prefrontal cortex (PFC)—especially the left and right frontal regions—helps us encode, retrieve, and organize information in working and long-term memory.
Brain-imaging studies support this. In one study, participants searched for the letter a in words (a shallow, perceptual task) or categorized nouns as living/non-living (a deeper, semantic task). Recall was much better for words processed semantically and PET scans showed greater activation in the left inferior prefrontal cortex during semantic encoding (Kapur et al., 1994).
Another study found a pattern known as hemispheric specialization in memory:
- Left PFC is more active during encoding
- Right PFC is more active during retrieval (Craik et al., 1999)
Together, these findings suggest the prefrontal cortex helps us decide what to attend to, how to organize it, and how to pull it back out later.
Neurotransmitters
Memory formation is not just about brain structures—it also relies on chemical communication between neurons. Several neurotransmitters play key roles in memory processes:
- Epinephrine – boosts memory during emotional or stressful events
- Dopamine – important for motivation, reinforcement, and recall
- Serotonin – linked to mood and memory interactions
- Acetylcholine – essential for encoding; reduced in Alzheimer’s disease
- Glutamate – a major excitatory neurotransmitter that strengthens synapses
Although researchers still debate the exact role of each neurotransmitter (Blokland, 1996), one thing is clear: repeated neural activity leads to more neurotransmitter release, stronger synaptic efficiency, and long-term potentiation (LTP)—the biological foundation of memory consolidation.
This is why practice, rehearsal, and emotional intensity can make memories more durable.
Emotion and Memory
Emotional events are remembered more vividly than neutral ones. According to arousal theory, strong emotional experiences trigger the release of stress hormones and neurotransmitters that strengthen memory encoding (Christianson, 1992; McGaugh, 2003).
This helps explain:
- Why you remember your first breakup
- Why a car accident might feel unforgettable
- Why childhood songs or smells carry powerful emotional weight
flashbulb memories
A flashbulb memory is an exceptionally vivid and detailed recollection of an emotionally significant event. These memories often feel photographic—people can recall where they were, who they were with, even small details about the surroundings.
Classic examples of flashbulb memories include:
- The 9/11 terrorist attacks
- The Challenger explosion
- Personal events like the birth of a child or the moment of receiving big news
A Pew Research Center study found that 97% of Americans aged 8 or older on 9/11 can vividly remember how they learned about the attacks—even a decade later.
However, modern research shows an important nuance: flashbulb memories feel extraordinarily vivid—but they are not always accurate. Even though people are confident in them, recall tends to change subtly over time (Hirst & Phelps, 2016). Flashbulb memories can be highly emotional, but they are not perfect “photographs” of the moment.
Flashbulb memories can be positive (a surprise engagement), negative (a natural disaster), or personally meaningful (a family event)—not just national tragedies.