Answer: A stimulus is something which can bring change in the physiology of the organism and can generate an immune response.
Explanation:
The information from stimuli is passed from the sensory memory to the short duration memory through the process of cognitive process. In the cognitive process the one aspect of the environment is concentrated and the other aspects are ignored. This helps in registering the effect of stimulus on the brain and its retention in the memory and also filters the unwanted stimuli.
