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Poster Session B: Wednesday, August 13, 1:00 – 4:00 pm, de Brug & E‑Hall

Attention modulates within-category differentiation of natural auditory objects in human auditory cortex

Ilkka Muukkonen¹; ¹#NAME?

Presenter: Patrik Wikman

Categorical representations of auditory objects arise in non-primary auditory cortex. However, it is unclear whether these regions support subcategorical diff-erentiation (e.g., instrument types), and whether attention enhances this differentiation. fMRI data (n = 20) were acquired in two experiments: OA, where participants listened to sound objects (speech, instruments, animals); and 3OA, where they attended to designated objects in scenes containing one object per category. SVM decoders were trained on OA-data to distinguish subcategory objects (e.g., dog vs. bird). Decoders were tested: (1) on OA-data to identify regions with stimulus-dependent within-category differentiation; (2) on 3OA scenes to assess if attention boosts within-category differentiation (comparing attended vs. distractor object differentiation). Stimulus-dependent and attention-related speaker identity differentiation involved spectrally non-sensitive STG regions, whereas animal and instrument differentiation was confined to spectrally sensitive regions. Results suggest speaker identity differentiation involves higher-level object representations, while other naturalistic sounds are differentiated via lower-level acoustic features.

Topic Area: Object Recognition & Visual Attention

Extended Abstract: Full Text PDF