Final answer:
Divided attention refers to focusing on several different activities or stimuli at the same time, which can result in inattentional blindness, where unexpected stimuli are not perceived. This cognitive multitasking requires significant mental resources and attention, often leading to increased brain energy demands.
Step-by-step explanation:
The phenomenon you are referring to, where attention is divided among multiple tasks, is known as divided attention. This occurs when we engage in monitoring several stimuli or engaging in multiple activities simultaneously. Such multitasking can lead to fatigue, stress, and decreased awareness of other stimuli, a concept known as inattentional blindness. For example, learning to ride a bicycle while concurrently processing various tasks showcases our ability to divide attention.
In the case of the selective attention test by Daniel Simons and Christopher Chabris, participants fail to notice an unexpected stimulus (the gorilla) because they are so focused on counting basketball passes, exemplifying inattentional blindness. This highlights the limitation of our mental resources and the importance of conscious thought which requires significant attention. The act of balancing multiple tasks efficiently is taxing to our brain, requiring increased energy, glucose, and oxygen to maintain this level of focused mental activity.