Jasmine Kwasa – jkwasa@andrew.cmu.edu
Laura María Torres – lmtorres@bu.edu
Abby Noyce – anoyce@andrew.cmu.edu
Barbara Shinn-Cunningham – bgsc@andrew.cmu.edu
Carnegie Mellon University
5000 Forbes Ave
Pittsburgh, PA 15217
Popular version of paper ‘1pPPb – Top-down attention modulates neural responses in neurotypical, but not ADHD, young adults’
To be presented Monday afternoon, November 29, 2021
181st ASA Meeting
Competing sounds, like a teacher’s voice against the sudden trill of a cell phone, pose a challenge to our attention. Listening in such environments depends upon a push-and-pull between our goals (wanting to listen to the teacher) and involuntary distractions to salient, unexpected sounds (the phone notification). The outcome of this attentional contest depends on the strength of an individual’s “top-down” control of attention relative to their susceptibility to “bottom-up” attention capture.
We wanted to understand the range of this ability in the general population, from neurotypical functioning to neurodivergence. We reasoned that people with Attention Deficit Hyperactivity Disorder (ADHD) would perform worse when undertaking a challenging task that required strong top-down control (mental flexibility) and show altered neural signatures of this ability.
We created an auditory paradigm that stressed top-down control of attention. Forty-five young adult volunteers with normal hearing listened to multiple concurrent streams of spoken syllables that came from the left, center, and right (listen to an example trial below) while we recorded electroencephalography (EEG). We tested both the ability to sustain attentional focus on a single “target” stream (always heard from the center, depicted in black in Figure 1) and the ability to monitor the target but flexibly switch attention to an unpredictable “interrupter” stream from another direction if and when it appeared (depicted in red in Figure 1).
You can hear an example trial here:
A visual depiction of this clip is seen below:
We included key conditions in which the stimuli were identical between trials, but the attentional focus differed, allowing us to isolate effects of attention. The EEG recording allowed us to capture neural responses, called event-related potential (ERP) components, whose amplitudes reflect the strength of top-down relative to bottom-up attention.
We found that while volunteers performed within a large range from near-perfect to near-chance levels of attentive listening, ADHD did not influence who were among the best or worst. In fact, there were no significant differences between ADHD (N=25) and Neurotypical (N=20) volunteers in terms of reporting the order of the syllables. However, ADHD subjects exhibited weaker attentional modulation (less flexibility) of ERP component amplitudes than did neurotypical listeners.
Importantly, neural response modulation significantly correlated with behavioral performance, implying that the best performers are those whose brain responses are under stronger top-down control.
Together, these results demonstrate that in the general population of both neurotypical and neurodivergent people, there is indeed a spectrum of top-down control in the face of salient interruptions, regardless of ADHD status. However, young adults with ADHD might achieve attentive listening via different mechanisms in need of further investigation.
