selective attention

Meaning: Selective attention is focusing limited processing capacity on one stimulus or task while filtering out others. Models differ on where filtering occurs. In Broadbent's filter model, selection is early: unattended input is blocked based on physical features before its meaning is analyzed. Treisman's attenuation model says unattended input is weakened, not blocked, so strong signals such as your own name can still get through. Late-selection models (Deutsch and Deutsch) hold that input is analyzed for meaning first and selection happens afterward.

On the MCAT: A passage describes dichotic listening, where each ear hears a different message and the participant repeats (shadows) one of them. People usually report physical features of the unattended message, such as pitch, but little of its content, yet they often notice their own name. This is the cocktail party effect, and it favors attenuation over a strict early block. Inattentional blindness and change blindness show that unattended stimuli in plain view can go unnoticed.

Common confusion: Selective attention is not divided attention (performing two tasks at once) or sustained attention (vigilance over time). Filtering also does not mean unattended input is completely lost; the cocktail party effect shows that some of it is still processed.