Final answer:
The cocktail party effect challenges the Selective Attention Theory by demonstrating that unattended stimuli can capture our attention in a noisy environment.
Step-by-step explanation:
The cocktail party effect poses a significant challenge to the Selective Attention Theory. This cognitive phenomenon occurs when a person can focus on a single conversation in a noisy environment, like a cocktail party, while still being able to pick up important cues from the background noise, such as hearing their name called.
The difficulty this presents to Selective Attention Theory arises because the theory suggests that individuals can tune out unattended stimuli, yet the cocktail party effect shows that certain unattended stimuli can capture attention.
While the Information Processing Theory, Multitasking Theory, and Gestalt Psychology Theory all relate to cognitive processes and attention, it is the Selective Attention Theory that is directly challenged by the cocktail party effect because of its implications for how attention is directed and how unattended information is processed.