Figure 1.

Self-initiated auditory target recognition and ‘reversal’. A, Top, schematic of the operant conditioning chamber with two nose ports (one for self-initiation and one for target response), one speaker and one food dispenser. SI: Animal self-initiates by nosepoking in the initiation nose port. 1: A tone is played. 2: If the tone is a target tone, the animal should nosepoke in the detection port, separate from the from the initiation port. 3: The animal receives a food pellet reward for correct responses on ‘go’ trials. Bottom, schematic of the go/no-go auditory behavioral task. Target (red) and non-target (blue/black) tones were 100 ms in duration, distributed one octave apart between 0.5 and 32 kHz, and delivered in a random order at 70 dB SPL. When the task was ‘reversed’, one of the previously unrewarded tones (blue) became the rewarded tone, and the previously rewarded tone (red) became an unrewarded tone. B, An example rat trained on go/no-go task then reversed. The original target tone was 4 kHz and the reversed target tone was 1 kHz. Left, heat map shows the animal’s performance throughout training, with daily responses (%) to each tone. Right, selected response curves from individual days during different phases of reversal learning. Error bars are 95% confidence intervals.