Map of Richfield on Also called secondary gustatory cortex. secondary visual cortex (V2) the area immediately surrounding the primary visual cortex (see striate cortex) in the occipital lobes, receiving signals from it secondarily for analysis and further discrimination of visual input in terms of motion, shape (particularly complex shapes), and position. second-generation antipsychotic see antipsychotic. second messenger an ion or molecule inside a cell whose concentration increases or decreases in response to stimulation of a cell receptor by a neurotransmitter, hormone, or drug. The second messenger acts to relay and amplify the signal from the receptor (the first messenger) by triggering a range of cellular activities. second-order conditioning in pavlovian conditioning, the establishment of a conditioned response as a result of pairing a neutral stimulus with a conditioned stimulus that gained its effectiveness by being paired with an uncondi- tioned stimulus. See higher order conditioning. Map of Richfield 2016.