Emotion can help us recognize words more quickly, just like the context of a sentence can. But a new paper about the role of emotion in word recognition memory says we do not remember emotionally intoned speech as accurately as neutral speech - and if we do remember the words, they have acquired an emotional value.

Words spoken with a sad voice are more negative. In anger, sadness, exhilaration or fear, speech takes on an urgency that is lacking from its normal even-tempered form - louder or softer, more hurried or delayed, etc. This emotional speech immediately captures a listener's attention and so Annett Schirmer and colleagues from the National University of Singapore looked at whether emotion has a lasting effect on word memory.

A total of 48 men and 48 women listened to sadly and neutrally spoken words and were later shown these words in a visual test, examining word recognition and attitudes to these words. The authors also measured brain activity to look for evidence of vocal emotional coding.

Their analyses showed that participants recognized words better when they had previously heard them in the neutral tone compared with the sad tone. In addition, words were remembered more negatively if they had previously been heard in a sad voice.

The researchers also looked at gender differences in word processing. They found that women were more sensitive to the emotional elements than men, and were more likely than men to recall the emotion of the speaker's voice. Current levels of the female sex hormone estrogen predicted these differences.

They conclude: "Emotional voices produce changes in long-term memory, as well as capturing the listener's attention. They influence how easily spoken words are later recognized and what emotions are assigned to them. Thus voices, like other emotional signals, affect listeners beyond the immediate present."

Published in Cognitive, Affective&Behavioral Neuroscience.