Image Descriptions – Research Page
Auditory Perception Graphs
Left graph: In panel A, this graph shows that sustained negative voltage brain responses show that when people perceive two metronome-like streams of tones with different frequencies in a repeating low-high-low pattern, they have a larger brain response than when they perceive the tones as integrated into one stream of tones with an up and down pattern of frequencies. In panel B, this graph shows that when people switch their perception from one stream to two streams or vice versa, the sustained brain response is larger than when their perception stays the same.
Right panel: In panel A, this graph diagrams a computational framework for modeling three stages of processing in the auditory system, roughly corresponding to the 1) inner ear and auditory nerve (Peripheral Analysis), 2) the primary auditory cortex, and 3) the secondary auditory cortex in the anterior temporal lobe or ventral auditory pathway. Each stage of processing has different neural units that are tuned to different stimulus properties, and these units compete with each other via inhibitory connections and undergo adaptation when their activity is sustained over time. The units also are subject to neural noise, which causes random variability in their responses over time. Panel B shows the relationship between the parameters for inhibition, adaptation, and noise, and how they influence the activity of the neural units, along with the input of the sound sequences.
Music Perception Diagram
The upper left panel shows the average ratings of fit between music and a click track that has notes at locations corresponding to the beat level and the measure level of the music. When the beat level of the click track is matching the music, people give much higher ratings than when the click track is mistmatching. The other panels show that this effect gets larger as children get older from age 5 to 17 years. The panels also show that children are largely not sensitive to whether the measure level of the click track matches the music or not. In contrast, adults (not shown in this figure) show a small but robust sensitivity to measure-level matching, and this effect is larger in musicians than non-musicians.
