Our Brains May Be Automatically Filtering Out Negative Words

We tend to assume that emotionally charged words are more likely to grab our attention. An insult shouted across a crowded room or a disturbing phrase overheard on television can seem impossible to ignore. But a new study published in Psychological Science suggests the opposite may happen before words reach conscious awareness.

Researchers at the Hebrew University of Jerusalem found that when people were focused on a visual task, they were less likely to consciously notice negative spoken words than neutral ones. The findings offer new insight into how the brain determines which information enters conscious awareness and which remains outside it.

“This study is a nice example of how our conscious intuitions regarding what we notice are not always what our unconscious is doing,” said lead author Gal R. Chen, a doctoral candidate in psychology at the Hebrew University of Jerusalem.

Although much of the brain’s processing occurs outside of conscious awareness, scientists know little about how information is selected to enter consciousness, particularly in hearing. Insights into this process could explain how nonconscious information might influence an individual’s thoughts, feelings, and behavior. 

Much of what scientists know about nonconscious processing comes from studies of vision in which researchers briefly flash images that participants are unable to consciously report seeing. Speech, however, presents a different challenge because spoken words, unlike images, cannot be delivered in a split second. Researchers have therefore struggled to determine how much information the brain can process from spoken language before a person becomes aware of it.

Chen and his colleagues set out to examine whether the emotional meaning of spoken words influences their chances of reaching awareness when people are focused on another task.

In the study, 101 Hebrew-speaking adults were instructed to identify whether a figurine on a screen was identical to the one before it while listening to a stream of meaningless pseudowords. Occasionally, a real Hebrew word, either emotionally negative or emotionally neutral, was inserted into the audio stream. After hearing the word, participants were asked whether they had noticed it and completed additional tests designed to measure their awareness.

“We assumed initially that people would notice the negative stuff more because that is our conscious intuition,” Chen said. “There is a lot of data showing that when you see or hear something negative you slow down or make more mistakes.”

Instead, the opposite happened: Participants were more likely to notice the neutral words over the negative words.

“We thought it was a mistake,” Chen said. “So we repeated the study while adding new words. The results gave us the same trend: People notice negative words less.”

The effect persisted when the researchers repeated the experiment with the same visual task but a larger set of words. To examine whether the observation was specific to conditions of high effort, the researchers conducted the experiment again, but this time replaced the demanding visual task with a much easier one. Again, participants were more likely to notice neutral words over negative ones.  

One possible explanation for this observation, the researchers said, is that consciously experiencing negative information is costly, and the cognitive system sometimes opts not to pay this price.

“It may be the default of the unconscious mind to suppress information that may be harmful to us,” Chen said. “If your primary task is to talk to me, random words popping up are not helpful. And if these words slow you down, the default unconscious bias might be, ‘don’t bring them around.’”

The findings may offer new avenues for studying mental health conditions. Chen speculates that future research could investigate whether the same unconscious filtering process operates differently in people with anxiety disorders, phobias, or post-traumatic stress disorder.

“The normal population notices negative words less often compared to neutral words,” Chen said. “In a clinical population, they might not have this selection bias.”

“If you think of the unconscious as a gatekeeper guarding us against things that may harm us or influence our decisions, you might ask what happens if this gatekeeper screws up,” he added.

Chen noted that the study has limitations. For example, it examined single words rather than conversations or natural speech, and it did not test highly positive or taboo words, which could produce different results. He said that future research could explore whether the same effects appear in sentences, stories, and more realistic listening environments.

For now, he said, the findings suggest that the nonconscious mind may play a larger role in shaping our everyday experiences than we realize.

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Reference

Chen, G.R., Maswadeh, Z., Deouell, L., & Hassin, R.R. (2026). Conscious detection of spoken words depends on their valence. Psychological Science, 47(5), 303–317.