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Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning
Published on: October 22, 2015
Activity related to perceptual judgment and action in primary auditory cortex
Mamiko Niwa1, Jeffrey S Johnson, Kevin N O'Connor
1Center for Neuroscience, University of California, Davis, Davis, California 95618, USA.
Summary
The primary auditory cortex (A1) dynamically integrates multisensory and task information. A1 neural activity, particularly firing rates, correlates with macaque choices in amplitude modulation (AM) discrimination tasks.
Area of Science:
- Neuroscience
- Auditory Perception
- Decision Making
Background:
- The primary auditory cortex (A1) is increasingly recognized for its role beyond unisensory processing.
- A1 is now understood to integrate multisensory and task-related information dynamically.
- This study investigates A1's role in a complex auditory discrimination task.
Purpose of the Study:
- To determine if single-unit (SU) and multiple-unit (MU) activity in A1 correlates with behavioral choices in macaques.
- To explore the relationship between A1 neural activity and the reporting of amplitude modulation (AM) in noise.
- To investigate potential attentional effects and the role of A1 in decision-making processes.
Main Methods:
- Macaques were trained on an amplitude modulation (AM) noise discrimination task involving lever responses.
- A1 SU and MU activity were recorded and compared between trials where AM was reported versus not reported.
- Analysis focused on neural firing rates and phase locking to AM stimuli relative to behavioral outcomes.
Main Results:
- A significant percentage of MUs (47.4%) and SUs (22.8%) increased firing before behavioral responses indicating AM detection.
- Increased firing rates during stimulus presentation were observed in 19.6% of MUs and 13.8% of SUs when AM was reported.
- A1 neural activity correlated with AM sensitivity, and firing rate codes were more strongly associated with task performance than phase locking.
Conclusions:
- A1 activity is modulated by task demands and behavioral choices, supporting its role in dynamic information integration.
- Neural activity in A1 reflects attentional processes or provides input to higher decision-making areas.
- A1 neurons, particularly AM-sensitive ones, play a crucial role in AM discrimination tasks, with firing rates being a key code.
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