Anxiety Limits Our Ability to Discriminate Faces and Speech

Anxiety can impair our accuracy on face- and word-recognition tasks, providing another possible source of fallibility in eyewitness testimony, according to research presented in two reports published in Psychological Science.

In the first report, participants were asked to breathe through a mask that provided normal air or a mask that provided CO₂-enriched air, a reliable method of inducing anxiety.

The participants were then asked to discriminate between similar sounding phonemes, or letter sounds. For instance, though the /g/ and /k/ sounds are similar in “gift” and “kift,” people generally hear “gift” because it’s a familiar word. In this particular task, the researchers presented phonemes that spanned continuum from one sound to the other, so that some sounded much more like “gift” and some sounded much more like “kift.”

The participants who breathed normal air performed well on this task – they were able to discriminate the two sounds most of the time. The CO₂ group, however, performed significantly worse. Their ability to discriminate between the sounds was lessened due to anxiety.

Anxiety is a common experience in everyday life, and these results reveal that our ability to process speech sounds may be far more malleable than previously thought.

The second report indicates that this malleability is also at work while discriminating between faces.

In this experiment, anxiety reduced discrimination only for those faces that were “hits” — that is, anxious participants were worse at recognizing that two faces were actually the same person. Anxious and non-anxious participants were equally proficient, however, at recognizing when the two faces were different people.

These results are important for understanding the factors that can compromise eyewitness testimony, the researchers conclude. Typically, people attribute poor eyewitness testimony to problems with remembering an event, people, or conversations. Yet this research reveals that anxiety could also play an important role, both in recognizing faces and understanding ambiguous words.

Mattys S.L., Seymour F., Attwood A.S., & Munafò M.R. (2013). Effects of acute anxiety induction on speech perception: Are anxious listeners distracted listeners? Psychological Science, 24 (8), 1606-8 DOI: 10.1177/0956797612474323

Attwood A.S., Penton-Voak I.S., Burton A.M., & Munafò M.R. (2013). Acute anxiety impairs accuracy in identifying photographed faces. Psychological Science, 24 (8), 1591-1594 DOI: 10.1177/0956797612474021