Treisman found that attention can be switched to unattended information if it is meaningful, which is supported by the cocktail party effect in which we can be in conversation with someone, overhear our name and switch attention to what we find meaningful.

Limited Capacity Attention.
Our brains are limited in the amount of information they can take in at any one time. Kahneman says we have a limited capacity central processor theorises this works in tandem with top down knowledge already stored in memory.

However....
McLeod suggests we have multiple pools of resources for drawing on tasks and no central processor.

Attention Spotlight.
We cannot process everything in our visual field and the Attention Spotlight is a metaphorical description of how one part of the field has priority.

The idea of an attention spotlight is important as it suggests we have control over what we process and that attention is selective.

Bottleneck Theories of Attention.
Bottleneck theories of attention suggest attention resources are limited. Broadbent suggests this happens early on in the attention process.