As a subject matter expert in neuroscience and psychology, I can explain the term "subthreshold" in the context of stimulus perception and response. In the field of sensory processing, a subthreshold stimulus is one that does not reach the minimum level required to be detected or to provoke a response. This means that even though the stimulus is present, it does not produce a conscious perception or an observable reaction in the organism. The threshold is the point at which a stimulus becomes strong enough to be noticed or to elicit a response. For example, in vision, if a light is dimmed to a certain level where it is no longer visible to the observer, that light is considered subthreshold. Similarly, in hearing, a sound that is too soft to be heard is subthreshold. The concept of subthreshold also extends to other areas such as learning and memory, where information that is not strong enough to be remembered or learned is considered to be below the threshold. read more >>

Definition: Sub-threshold (or subthreshold) refers to a stimulus that is too small in magnitude to produce an action potential in excitable cells. In general, a sub-threshold stimulus leads to the depolarization of the membrane, but the magnitude of the depolarization is not large enough to reach the threshold voltage.read more >>