The story behind our emotions and sentiments

By Carla-Ioana Gheorghe

Emotions and sentiments are integral to human experience. They guide our decisions, shape our relationships, and influence our mental and physical health. But how do these powerful internal states arise in the brain? Modern neuroscience has shed significant light on the mechanisms behind emotions, identifying key brain structures and processes that contribute to their formation.

What Are Emotions and Sentiments?

Emotions are short-lived, intense reactions to specific impulses—whether external (a threat, a compliment) or internal (a memory, a thought). They involve physiological changes (like heart rate increase), behavioral responses (like smiling or fleeing), and subjective feelings (like fear or joy).

Sentiments, in contrast, are longer-lasting affective states. While emotions might flare in seconds, sentiments—such as love, resentment, or loyalty—develop over time and reflect ongoing attitudes.

How do emotions form in the brain?

Emotions are complex, involving multiple brain regions that seem to work together like an harmonious orchestra:

1. Amygdala: The Emotional Alarm System

The amygdala plays a critical role in detecting emotionally significant stimuli, especially threats. When you see a barking dog, for example, the amygdala activates almost instantly, triggering fear and preparing your body to respond.

2. Hypothalamus: The Physiological Controller

Once the amygdala flags an emotional event, the hypothalamus springs into action, controlling autonomic responses like increased heart rate, sweating, and hormone release (e.g., adrenaline and cortisol).

3. Prefrontal Cortex: Emotional Regulation and Evaluation

The prefrontal cortex helps assess emotional situations and regulate responses. It’s involved in decision-making, impulse control, and interpreting complex social emotions like guilt or empathy.

4. Hippocampus: Memory and Context

The hippocampus contributes to emotional responses by transforming emotions into memories. It helps the brain interpret whether a stimulus is dangerous or safe, based on past experiences.

5. Insula: Feeling Emotions Viscerally

The insular cortex is associated with the subjective awareness of internal states—like disgust, pain, or love. It helps turn physical sensations into emotional experiences.

What triggers emotions?

Emotions can be triggered by a wide range of inputs:

• Sensory stimuli: A loud bang may trigger surprise or fear.

• Cognitive appraisals: Thinking about a loved one may trigger warmth or longing.

• Memories: Recalling a past failure can reignite feelings of shame or regret.

• Social cues: A smile, a frown, or tone of voice can evoke emotions instantly.

• Bodily states: Hunger or fatigue can intensify irritability or sadness.

These triggers are often interpreted unconsciously by the brain before we become fully aware of how we feel. This process can happen in milliseconds, especially with emotions like fear or anger.

How do sentiments develop?

While emotions are immediate, sentiments require repeated emotional experiences and reflection over time. For example, love may begin with infatuation (a high-intensity emotion), but matures into a deeper sentiment through shared experiences, trust, and commitment. This transition involves:

• Reinforcement learning in the brain, especially in dopamine-rich areas.

• Long-term memory consolidation, influenced by the hippocampus and prefrontal cortex.

• Social and cultural factors, shaping how we interpret and express sentiments.

  

Conclusion

Emotions and sentiments are not merely feelings—they’re complex neurological processes that integrate perception, memory, and bodily awareness. They form in the brain through the interaction of multiple systems, including the amygdala, prefrontal cortex, insula, and hippocampus. While emotions arise quickly in response to stimuli, sentiments evolve over time, reflecting deeper psychological patterns.

Understanding how these affective processes work gives us greater insight into ourselves and others—and empowers us to manage our emotions in healthier, more constructive ways.

References

1. https://www.news-medical.net/health/What-is-the-Hypothalamus.aspx

2. https://pubmed.ncbi.nlm.nih.gov/20946960/

3. https://www.researchgate.net/publication/273304000_Feelings_What_Are_They_How_Does_the_Brain_Make_Them

4. https://www.researchgate.net/publication/7449559_Emotion_and_Cognition_Insights_from_Studies_of_the_Human_Amygdala

5. LeDoux, Joseph E. (2000). "Emotion circuits in the brain."Annual Review of Neuroscience, 23, 155–184.

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7. Pessoa, Luiz (2008). "On the relationship between emotion and cognition." Nature Reviews Neuroscience, 9(2), 148–158.

8. Davidson, Richard J., & Irwin, W. (1999). "The functional neuroanatomy of emotion and affective style." Trends in Cognitive Sciences, 3(1), 11–21.

9. Adolphs, Ralph (2010). "What does the amygdala contribute to social cognition?" Annals of the New York Academy of Sciences, 1191(1), 42–61.