Theories of Attention

Bottleneck Theories or Filter Theories (Broadbent 1958) 

Broadbent (1958) proposed that physical characteristics of messages are used to select one message for further processing and all others are lost. In other word this bottleneck limits the quantity of information to which we can pay attention. However these theories lost popularity because they underestimated the flexibility of human attention (Eysenck 1982) 

Automatic versus Controlled Processing 

Automatic/controlled processing theory assumes that human performance is the result of two qualitatively different processes; automatic and controlled processing. Automatic processing is a fast, parallel process not limited by short term memory. Automatic processing uses little subject effort, permits little direct subject control, but requires extensive and consistent training to develop. Controlled processing is a comparatively slow, serial process limited by short term memory. Controlled processing requires subject effort, permits a large degree of subject control, but needs little training to develop. 

Automatic Processing can be done with minimal mental effort , for example: walking and talking. 

Control Processing requires a mental effort, for example: studying for an exam and solving relationship problem. 

Features Integration Theory

The feature integration theory was proposed by Treisman (1988, 1992). Treisman distinguished between the features of objects (e.g. size, colour) and the objects themselves and made the following assumptions: 

1. There is rapid initial parallel processing in which the visual features of objects in the environment are processed together; this is not dependent on attention. 

2. There is then serial processing in which features are combined together to form objects. 

3. The serial process is slower than the initial parallel process, especially when the set size is large. 

4. Features can be combined by focused attending to the location of the object, in which case focused attention provides the ‘glue’ forming unitary objects from the available features. 

5. Feature combination can be influenced by stored knowledge. 

6. In the absence of focused attention or relevant stored knowledge features from different objects will be combined randomly, producing illusory conjunctions.