Sensory noise predicts divisive reshaping of receptive fields
(a) The presumed goal of perception is to infer the state of the external world from received sensory cues. Here, two possible events (someone arriving at the door, and a telephone call) can give rise to three sensory cues (a knocking sound, ringing sound, or vibration). The ringing sound is ambiguous: it can come from either the door bell or the phone. Cues, such as a vibrating telephone, can resolve this ambiguity: here, increasing the chances that the phone is ringing, while decreasing the chances that there is someone at the door. Such competition between different explanations for received sensory cues is called ‘explaining away’. (b-c) In sensory neural circuits, explaining away results in suppression from non-preferred stimuli in the surround. Its effects vary dramatically, depending on whether inhibition acts (b) globally on the neural responses or (c) selectively, on certain neural inputs. (d-e) Hypothetical response of ‘door’ and ‘phone’ selective neurons, in response to different combinations of sensory cues. The qualitative effects of explaining away depend on whether it (d) globally suppresses the response of one or other detector, or (e) selectively suppresses the influence of certain cues.