Having detected information, our mental resources are concentrated on specific elements – this is “attention”. Although attention can move very quickly from one item to another, it can only deal with one item at a time. Attention can take the form of:
- Selective attention
- Divided attention
- Focused attention
- Sustained attention
Selective attention occurs when a person is monitoring several sources of input, with greater attention being given to one or more sources which appear more important. A person can be consciously attending to one source (e.g. the co-pilot) whilst still sampling other sources in the background (e.g. ATC transmissions). Psychologists refer to this as the ‘cocktail party effect’ whereby you can be engrossed in a conversation with one person but your attention is temporarily diverted if you overhear your name being mentioned at the other side of the room, even though you were not aware of listening in to other people’s conversations. Similarly, flight crew may be talking with one another, but as soon as they recognise their own callsign on the radio frequency, their attention is diverted. Distraction is the negative side of selective attention.
Divided attention is common in most work situations, where people are required to do more than one thing at the same time. Usually, one task suffers at the expense of the other, more so if they are similar in nature. This type of situation is also sometimes referred to as time sharing.
Focused attention is merely the skill of focusing one’s attention upon a single source and avoiding distraction. Cognitive ‘blackholing’ is the negative side of focused attention, where attention is so focused on one area that other important information is not noticed.
Sustained attention as its name implies, refers to the ability to maintain attention and remain alert over long periods of time, often on one task. Most of the research has been carried out in connection with monitoring radar displays. Attention is influenced by arousal level and stress. This can improve attention or damage it depending on the circumstances. Perception involves the organisation and interpretation of sensory data in order to make it meaningful, discarding non-relevant data, i.e. transforming data into information. Perception is a highly sophisticated mechanism and requires existing knowledge and experience to know what data to keep and what to discard, and how to associate the data in a meaningful manner. An example of the perceptual process is where the image formed on the retina is inverted and two dimensional, yet we see the world the right way up and in three dimensions; if the head is turned, the eyes detect a constantly changing pattern of images, yet we perceive things around us to have a set location, rather than move chaotically.