This repository contains the data and codes for the paper
The precedence effect in spatial hearing manifests in cortical neural population responses
For the behavioral experiment, four female Wistar rats were trained to perform a two-alternative forced-choice (2-AFC) near-field lateralization task. The animals initiated a trial by licking a center spout, were presented with an acoustic stimulus over tube phones, and then responded by licking response spouts on the left or right. Correct responses were positively reinforced with drinking water; incorrect responses triggered a short timeout. A trial following the incorrect response is the "correction trial", which would be exculded from the final data analysis.Our temporal weighting funtion (TWF) stimuli consisted of a brief tain of eight binaural pulses presented at a rate of 20, 50, 300 or 900 Hz, with the ITD for each of the pulses drawn independently and uniformly from the range of ± 0.125 ms. We generated two types of such TWF stimuli: In stimuli for “honesty trials”, the ITDs for all 8 pulses were either positive (right ear leading) or negative (left ear leading), and the rat had to respond on the appropriate side to receive a reward. In contrast, in “probe trial” stimuli, the ITDs were unconstrained, there is not a priori correct lateralization, and the animals were free to choose to respond as they pleased and were rewarded regardless.
For the Electrocorticographic (ECoG) experiment, nine female Wistar rats were recorded from left and/or right auditory cortex. The stimuli in ECoG recording were simplier, reducing the number of pulses in the train from 8 to only 4, and by constraining each pulse so that it could take only one of two possible ITD values, either -0.164 ms or +0.164 ms. In total, we recorded electrophysiological responses to this set of sparse TWF stimuli at 12 ECoG electrode placements: 4 placements from the right AC of each of the 4 trained animals in our cohort, and another 3 from the left AC of 3 of the 4 trained animals, plus another 5 recordings from the right AC of an additional five untrained animals which had not been exposed to the TWF stimuli prior to the electrophysiological experiments. At each electrode placement, we recorded responses to our sparse TWF stimuli at two pulse rates: 300 Hz and 900 Hz.
