Final answer:
The correct term for the ratio of incoming information to random background information is c. 'signal-to-noise ratio (SNR)', which is a component of signal detection theory. Decreased sensitivity to an unchanging stimulus is incorrectly referred to as a difference threshold; the correct term for this phenomenon is either 'habituation' or 'adaptation'.
Step-by-step explanation:
The quantity of incoming information compared to the level of random background information is known as the c. signal-to-noise ratio (SNR). This concept falls within the realm of signal detection theory, which addresses our ability to identify a stimulus when it is embedded in a distracting background. Motivation plays a significant role in signal detection, as it can enhance our ability to discern meaningful stimuli amidst noise. For instance, a mother's heightened sensitivity to her baby's sounds, or an air traffic controller's capacity to identify aircraft signals on a radar filled with various blips, can both be explained using signal detection theory.
As for the second question, decreased sensitivity to an unchanging stimulus is known as b. difference threshold. This phenomenon is typically referred to as habituation or adaptation in the context of sensory experience.