Inattentional blindness is

• A. Brain function
• B. Difference threshold
• C. Detecting stimuli under uncertainty
• D. Missing visible objects

Answer: (D)

Inattentional blindness is the failure to notice a visible object because attention is occupied elsewhere. It shows that perception depends on where we allocate our cognitive resources, not just what our senses detect. When you’re focused on a task, your brain processes the task-relevant information deeply while obvious stimuli can slip past us. A classic example is people counting passes who don’t notice a person in a gorilla suit walking through the scene, even though the gorilla is clearly visible. The object was there, but the attentional bottleneck prevented it from entering conscious perception. This isn’t just about brain function in general or about changes in sensory thresholds, and it isn’t simply about detecting stimuli under uncertainty. It specifically captures how focused attention can cause obvious things to be missed.