People make first impressions so quickly that they’ve already formed their opinions before they even realize they did. For example, research has found that it takes no more than 50 milliseconds — 0.05 seconds — for Internet users to form an opinion about a website. What’s more, people decide whether a person is trustworthy or not within just a tenth of a second.
The reason first impressions last so long in a person’s mind may be because of the emotional impact those impressions have. A new study published in the journal ELife suggests that emotions directly influence learning and memory processes in the brain.
Researchers from the University of Haifa in Israel analyzed the electrical activity in the brains of rats during social behavior. They found that a state of excitement produced strong rhythmical activity, which was particularly strong and synchronous between areas of the brain associated with social memory during the first encounter between two rats who’d previously never met. The more the rats encountered one another, the more this rhythmical activity declined both in strength and in the levels of coordination between different brain areas.
“It turns out that different emotions cause the brain to work differently and on distinct frequencies,” lead author Dr. Shlomo Wagner said in a press release. “We found a connection between the feeling of excitement, rhythmical activity in specific brain areas, and the cognitive process of memory formation. In essence, this finding explains why people tend to remember in particular their first encounter with a future friend or partner.”
Earlier this year, researchers from New York University found that the brain could retrieve memories better if the memories were associated with emotions. They also found that over time, memories were strengthened, and that different emotions influenced different parts of the brain.
“We will need to conduct additional studies in the future in order to understand the precise ramifications of each emotion on memory,” said Wagner. “But in broad terms the implication is clear. Different emotions cause the brain to work differently, including in terms of cognitive processes such as learning and memory.”