Kahneman's capacity model of attention refers to the idea that attention is a limited resource and that we have a limited capacity for processing information at any given time. According to this model, there is a central bottleneck in the processing of information, and the amount of information that can be processed at one time is limited.
Kahneman's capacity model suggests that we have two modes of processing information: the automatic mode and the controlled mode. The automatic mode is fast, effortless, and unconscious, while the controlled mode is slow, effortful, and conscious. According to the model, the automatic mode is responsible for the processing of simple and routine tasks, while the controlled mode is responsible for the processing of complex and novel tasks. The model can be used to explain inattentional blindness, the phenomenon in which we fail to see objects or events in our environment when our attention is focused elsewhere. According to the model, when our attentional capacity is fully occupied by a task, we are less likely to notice unexpected events, because our automatic mode is unable to process the information.