Contextual effects on loudness judgments for sounds with continuous changes of intensity are reflected in nonauditory areas. Issue 6 (5th February 2021)

• Record Type: Journal Article
• Authors: Behler, Oliver; Uppenkamp, Stefan
• Is Part Of: Human brain mapping. Volume 42:Issue 6(2021)
• Page Start: 1742
• Page End: 1757
• Publication Date: 2021-02-05
• Subjects: auditory cortex -- auditory fMRI -- context effects -- loudness judgments -- orbitofrontal cortex; Brain mapping -- Periodicals; 611.81
• DOI: 10.1002/hbm.25325
• Languages: English
• ISSNs: 1065-9471

Abstract

Abstract: Psychoacoustic research suggests that judgments of perceived loudness change differ significantly between sounds with continuous increases and decreases of acoustic intensity, often referred to as "up‐ramps" and "down‐ramps." The magnitude and direction of this difference, in turn, appears to depend on focused attention and the specific task performed by the listeners. This has led to the suspicion that cognitive processes play an important role in the development of the observed context effects. The present study addressed this issue by exploring neural correlates of context‐dependent loudness judgments. Normal hearing listeners continuously judged the loudness of complex‐tone sequences which slowly changed in level over time while auditory fMRI was performed. Regression models that included information either about presented sound levels or about individual loudness judgments were used to predict activation throughout the brain. Our psychoacoustical data confirmed robust effects of the direction of intensity change on loudness judgments. Specifically, stimuli were judged softer when following a down‐ramp, and louder in the context of an up‐ramp. Levels and loudness estimates significantly predicted activation in several brain areas, including auditory cortex. However, only activation in nonauditory regions was more accurately predicted by context‐dependent loudness estimates as compared with sound levels, particularly in the orbitofrontal cortex and medial temporal areas. These findings support the idea that cognitive aspects contribute to the generation of context effects with respect to continuous loudness judgments. Abstract : Normal hearing listeners continuously judged the loudness of complex‐tones with dynamic intensity while auditory fMRI was performed. Stimuli were judged louder when following a sequence of increasing level, and softer when the preceding levels were decreasing. Neural correlates of these context effects were exclusively identified in nonauditory brain regions, suggesting a cognitive contribution.