Depressive symptoms can lead to a false perception of ambiguity

Joyce Chen ‘23

Figure 1. People struggling with depression tend to think more negatively because of their biased processing.

Unlikely to experience optimism, many depressed individuals often times perceive ambiguity in a negative fashion. Their perception of reality is morphed by their emotions and they misunderstand other people’s intentions due to their subjective feelings. They have a negatively biased interpretation of the world, thereby leading to self-doubt and isolation. Thus, a depressed disposition can cause and worsen negative ambiguity processing. 

A study led by Xiao-Xiao Lin from the CAS Key Laboratory of Mental Health at the Institute of Psychology in Beijing, China aimed to prove whether or not depression affects the processing of ambiguity by morphing an individual’s emotions towards the cues. The group tested this hypothesis by altering the moods of two randomly assigned subject groups, plus one control group, out of a total of one hundred and thirty six college students, ages ranging from 18 to 29 years old. Each group represented a different category of depression: induced depression, spontaneous depression (control group), and neutral. The induced depression group was instructed to watch a four-minute video from a Chinese film called Aftershock under the impression that they were to express their underlying emotions to feel from the perspective of the character. In the video, a mother had to choose to save her son over her daughter during an earthquake; the purpose of this film was to induce a depressive state, as it depicts personal loss. With the same instructions, the neutral group viewed a clip from a Chinese documentary on repairing palace relics. The control group was shown the same clip, but viewed the video with concentration instead. Afterwards, the groups were exposed to five different auditory cues; the highest and lowest frequencies were reference tones, one associated with monetary reward (Rt), and the other with monetary punishment (Pt), and the other three pitches were ambiguous cues — near-rewarding tone (NRt), middle tone (Mt), and near-punishing (NPt). The subjects had to identify which tones represented reward or punishment by pressing either the REWARD or the PUNISHMENT button. 

Based off of the lack of money the control group received, researchers discovered that they had more depressive symptoms and thoughts. The control and sad groups preferentially interpreted Mt, the fully ambiguous cue, as punishment in comparison to the neutral group. Furthermore, the control group judged the NRt as punishment compared to the sad and neutral groups. As a result, the control group had a bias towards negativity due to their tendencies to falsely judge the ambiguous cues as punishment. The findings of Lin and his team can provide insight for cures for depression, as it displays that negative processing biases can lead to depression, but further studies are required for the clinical population.  



  1. L. Xiao-Xiao, et al., Ambiguity processing bias induced by depressed mood is associated with diminished pleasantness. Scientific Reports 9 (2019). doi:10.1038/s41598-019-55277-6
  2. Image retrieved from:

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