What is a spectrotemporal response field in the auditory system?

In the auditory system, a spectrotemporal response field (STRF) is a characterization of a neuron's stimulus selectivity that captures how its response properties evolve over time.1

While receptive fields in visual and somatosensory systems are often described as spatial entities, auditory receptive fields are defined by the specific set of frequencies to which a neuron responds, reflecting the tonotopic organization of the basilar membrane. The STRF is determined using techniques such as spike-triggered averaging and reverse correlation, which involve computing a cross-correlation between a neuron's spike train and the preceding stimulus occurrences.1

Essentially, these methods look backward in time from the occurrence of a spike to identify the average stimulus—characterized by both frequency (spectral) and timing (temporal) components—that elicited that response. This approach allows researchers to map how excitatory and inhibitory subregions of a neuron's response field change following the presentation of a sound, providing insight into how the auditory cortex processes complex acoustic information beyond simple frequency detection.12