How Emotions Influence Our Memory Formation

Memories linked with strong emotions often become seared in the brain. This is because, during an emotional event, multiple neurons in the brain must fire in synchrony to create strong emotional memories. The hippocampus records the details of the event, and the amygdala helps the hippocampus store memories more effectively, resulting in stronger memories.

Emotions can also be attached to memories after the event has occurred. For example, if a person has a great weekend trip with a friend, the emotion attached to that experience would probably power the formation of a lasting memory. The emotional quality of the memory may cause happiness upon seeing that friend, and approach behaviour to that social partner. In this way, the great trip with the friend is more emotionally charged and important for guiding future behaviour than a non-emotionally charged commute trip that is quickly forgotten.

Emotions can also change the way we remember events. For example, when recalling a memory, if someone is recalling an event by themselves or within a group of people, the emotions that they remember may change as well as the recall of specific details. Individuals recall events with stronger negative emotions than when a group is recalling the same event. Collaborative recall causes strong emotions to fade and the emotional tone changes.

Emotions can also be attached to memories after the event has occurred. For example, if a person has a great weekend trip with a friend, the emotion attached to that experience would probably power the formation of a lasting memory. The emotional quality of the memory may cause happiness upon seeing that friend, and approach behaviour to that social partner. In this way, the great trip with the friend is more emotionally charged and important for guiding future behaviour than a non-emotionally charged commute trip that is quickly forgotten.

The amygdala and hippocampus work together to enhance emotional memory

The amygdala and hippocampus are two parts of the brain that work together to enhance emotional memory. The amygdala is responsible for emotional arousal processing and the modulation of memory processes, while the hippocampus is involved in the potentiation and consolidation of declarative memory. When an emotional experience occurs, the amygdala becomes highly active, signalling the hippocampus to strengthen the encoding and consolidation of these memories. This process is facilitated by the release of stress hormones and neurotransmitters, which modulate synaptic plasticity and enhance neural connectivity. The amygdala and hippocampus are synergistically activated during memory encoding, with the amygdala modulating memory consolidation and the hippocampus being responsible for successful learning and long-term memory retention.

The amygdala and hippocampus also work together to connect memories to emotions, generating an emotional response. This connection plays a role in emotions such as fear and anger, as well as in the "fight or flight" response. The amygdala's involvement in emotional processing strengthens the memory network and enhances memory consolidation, resulting in stronger memories.

The neural mechanism underlying emotional memory enhancement involves the interaction between the amygdala and the hippocampus, as well as several other factors that prioritise the encoding of emotional experiences. Intracranial EEG studies have shown that the amygdala triggers pronounced hippocampal sharp-wave ripples after encoding emotional experiences, further reinforcing the consolidation of these memories during both awake and sleep. This coordinated activity between the amygdala and hippocampus ensures that emotionally significant events are prioritised in long-term memory storage.

Emotional memory is influenced by arousal and valence

Arousal and valence have been found to influence emotional memory. Arousal has been found to be the critical factor contributing to the emotional enhancement effect on memory. Arousal linked with emotion has been found to improve memory compared to arousal without emotion. Arousal has also been found to increase the duration of attentional focusing on arousing stimuli, delaying the disengagement of attention from it.

Valence has also been found to enhance memory. Non-arousing items with positive or negative valence have been found to be better remembered than neutral items. Valence has been found to be an essential step towards a more complete understanding of emotion effects on memory.

Emotional memory is enhanced by stress hormones and neurotransmitters

Stress hormones and neurotransmitters interact with the amygdala, a part of the brain that is responsible for emotional responses. The amygdala is activated by emotional arousal and is a critical step in enabling stress hormones to modulate memory processes. The amygdala interacts with other brain regions, including the hippocampus and the prefrontal cortex, to regulate the consolidation of different types of information.

The amygdala is not a site of permanent storage of the enhanced memory trace but rather is involved in strengthening consolidation processes in other brain regions. The amygdala interacts with the hippocampus, which is involved in spatial and contextual components of training. The amygdala also interacts with the prefrontal cortex, which is involved in higher cognitive functions such as thought, decision-making, and working memory.

Stress hormones and neurotransmitters have been shown to enhance memory consolidation, which is the process of converting short-term memories into long-term memories. This enhancement is particularly relevant for emotional memory. The hippocampus, prefrontal cortex, and the amygdala are affected by stress.

Stress can also cause acute and chronic changes in certain brain areas, which can lead to long-term damage. Over-secretion of stress hormones can impair long-term delayed recall memory but can enhance short-term, immediate recall memory.

Emotional memory is influenced by individual differences

The effects of emotion on memory accuracy also depend on the resources that an individual has available to devote toward event processing. Individuals who can devote only limited cognitive resources to event processing (either because they are performing a secondary task or because they are individuals with relatively poor cognitive control ability) tend to show much larger emotion-related memory trade-offs than people who can devote more substantial cognitive resources to event processing.

In addition, the way in which cognitive resources are devoted toward information processing may also be closely tied to individual differences in personality or anxiety level. For example, people higher in anxiety tend to focus more automatically on negative event details, causing them to remember those details better. However, they have a harder time remembering the contextual details, plausibly because they cannot flexibly deploy their attention away from the emotional aspects and toward nonemotional event details.

Emotional memory is influenced by age-related differences

The "positivity effect" is thought to be influenced by the following factors:

• Older adults tend to focus more on their internal state and how information makes them feel, rather than on objective event details.
• Older adults may have a greater reliance on schema-based reconstruction of emotional memories.
• Negative emotion tends to narrow attention onto the most arousing elements of an experience, which are often internal reactions.
• Older adults tend to focus on their emotional reactions when justifying their confidence in a memory.
• Older adults tend to remember how information made them feel better than they remember the information's content.
• Older adults may be more likely to reappraise emotional memories than young adults.
• Older adults may be more likely to remember positive experiences with rich detail when those experiences are closely tied to their self-concept.
• Older adults may be more likely to remember negative experiences with rich detail when those experiences are less personally relevant.
• Older adults may be more likely to remember positive low-arousal stimuli, while younger adults may be more likely to remember negative low-arousal stimuli.
• Older adults may be more likely to remember negative high-arousal information, while younger adults may be more likely to remember positive high-arousal information.
• Older adults may be more likely to remember negative low-arousal information with more internal details than positive low-arousal information.
• Older adults may be more likely to remember positive low-arousal information with more internal details than negative low-arousal information.

Frequently asked questions