Final answer:
Selective attention is when we focus only on certain aspects of an experience, leading to inattentional blindness, wherein other stimuli are missed even if plainly visible. This is because the brain prioritizes information based on relevance to the task at hand or survival, not on the completeness of sensory input.
Step-by-step explanation:
Selective attention occurs when we only focus on certain elements in our environment, disregarding other stimuli. We attend solely to a specific aspect of an experience, which can lead to our missing out on other clearly visible information around us.
One classic example illustrating this concept is the experiment by Simons and Chabris where participants counted basketball passes among players and often missed a person in a gorilla suit walking through the scene. This phenomenon, known as inattentional blindness, shows how our focus on one task can make us completely oblivious to other unexpected events in our surroundings, even when they are in plain sight. Our brain uses attentional filters to manage the vast amount of information we encounter, which can sometimes cause us to overlook significant details unrelated to our immediate focus.
Famous tests demonstrate that when our cognitive resources are tied up in tasks that require intense concentration, other stimuli that are not the main focus can easily be ignored, regardless of how conspicuous they may be. This concept is crucial in understanding our sensory perception and cognition, highlighting why we might not always 'believe our lying eyes' as our brain sketches out a summary of the world based on what it deems most relevant for our survival.