If you’re someone who suffers from anxiety, you’re probably already well aware you view certain situations and settings differently than others, but you may be surprised to learn that anxiety can affect perception on such a fundamental level that it can impact a person’s sense of hearing. A study published last week in Current Biology reveals that people with anxiety perceive the world differently from people without anxiety. The research suggests that people with anxiety may have difficulty, on a neurological level, in distinguishing between threatening and non-threatening stimuli, making them more likely to feel insecure and unsafe.
Scientists from the Weizmann Institute of Science, The Jerusalem Mental Health Center, and the Hebrew University in Israel analyzed the effects of anxiety on perception by having subjects identify sounds. They worked with 28 subjects who diagnosed with generalized anxiety disorder (GAD), a disorder characterized by chronic feelings of intense anxiety, even when there is little to be anxious about. GAD affects 6.8 million U.S. adults; women are twice as likely to develop GAD as men.
The researchers began the experiment by giving the participants money, and having them listen to three tones; one would result in a loss of money, one would win them money, and one had no consequence. The participants were able to differentiate between the sounds and knew which one came with a reward, and which one came with a deduction. In the next phase of the experiment, participants were asked to listen to a variety of tones, including the three from the previous game, and identify the sounds that they recognized. The researchers found that subjects who didn’t suffer from anxiety had little problem differentiating between the original sounds and the unfamiliar ones. The people with GAD, in contrast, had a much more difficult time distinguishing between the familiar sounds and the new ones.
The researchers suggest that these results stem from “overgeneralization,” a word that in psychological terms refers to someone who takes one frightening or unsafe experience and extrapolates it outward to all other similar experiences. New Scientist gives the example of being bitten by a dog: A non-anxious person bitten by a dog might reasonably be wary of similar dogs or similar situations, but a person with anxiety might overgeneralize and extend that reasonable cautiousness toward all dogs, regardless of size or threat-level. The researchers claim that although overgeneralization isn’t a new idea in studies of anxiety, there’s a lot we still don’t know about it, including whether it’s a conscious choice on the part of the person with anxiety, or whether it’s rooted in a more deeply-embedded process in the brain. This study suggests the latter — that test subjects with anxiety actually perceived the original sounds differently from others, and that that perception led them to overgeneralize in the second phase of the experiment. “People with anxiety have an altered perception of the world,” study co-author Rony Paz told New Scientist.
The researchers also used fMRIs to study the brains of test subjects with anxiety and found that their brains responded to stimuli differently from those without anxiety, particularly in the amygdala (the part of the brain associated with anxiety and fear) and in the areas of the brain that process sensory information. A press statement suggests that “[t]hese results strengthen the idea that emotional experiences induce changes in sensory representations in anxiety patients' brains.” This research also may give insight into why some people have a greater tendency toward anxiety than others.