Under certain circumstances, cortical neurons are capable of elevating their fring for long durations
in the absence of a stimulus. Such activity has typically been observed and interpreted in the context
of performance of a behavioural task. Here we investigated whether post-stimulatory activity is
observed in auditory cortex and the medial geniculate body of the thalamus in the absence of any
explicit behavioural task. We recorded spiking activity from single units in the auditory cortex (felds
A1, R and RT) and auditory thalamus of awake, passively-listening marmosets. We observed poststimulatory activity that lasted for hundreds of milliseconds following the termination of the acoustic
stimulus. Post-stimulatory activity was observed following both adapting, sustained and suppressed
response profles during the stimulus. These response types were observed across all cortical felds
tested, but were largely absent from the auditory thalamus. As well as being of shorter duration,
thalamic post-stimulatory activity emerged following a longer latency than in cortex, indicating that
post-stimulatory activity may be generated within auditory cortex during passive listening. Given
that these responses were observed in the absence of an explicit behavioural task, post-stimulatory
activity in sensory cortex may play a functional role in processes such as echoic memory and temporal
integration that occur during passive listening
