Push-pull competition between bottom-up and top-down auditory attention to natural soundscapes

Area of Science:

• Cognitive Neuroscience
• Auditory Perception
• Neuroscience of Attention

Background:

• Everyday environments require dynamic attentional resource allocation.
• Attentional systems must balance focus on targets with awareness of surroundings.
• Understanding the interplay of top-down and bottom-up attention is crucial.

Purpose of the Study:

• To investigate the neural mechanisms of attention in dynamic auditory scenes.
• To explore the push-pull interaction between endogenous (top-down) and exogenous (bottom-up) attention.
• To examine how salient background events modulate neural responses to attended auditory targets.

Main Methods:

• Electroencephalography (EEG) was used to record neural activity.
• Participants attended to a controlled rhythmic sound sequence.
• Natural soundscapes were presented as distractors to manipulate background salience.

Main Results:

• Salient auditory events in background soundscapes significantly suppressed neural responses (phase-locking and gamma activity) to the attended sequence.
• This suppression countered the enhancement effects typically seen for attended targets, supporting limited attentional resources.
• The degree of neural modulation by background salience was graded, indicating a continuous interplay.
• Both endogenous and exogenous attention engaged a common fronto-parietal network, but with different temporal dynamics.

Conclusions:

• Neural processing of attended auditory information is significantly modulated by salient, unexpected events in the auditory environment.
• Findings support a model of limited attentional capacity where bottom-up salience can override top-down control.
• The fronto-parietal network plays a key role in integrating endogenous and exogenous attentional demands in complex auditory scenes.