Chapter Summary

• Introduction. Attention generally refers to selectivity of processing. Access to consciousness is controlled by attentional mechanisms in the same way as what appears on a television screen is determined by which channel is chosen. Attention can be active and based on top-down processes or passive and based on bottom-up processes. It is important to distinguish between focused and divided attention. Most research on attention deals only with external, two-dimensional stimuli and the individual's goals and motivational states are ignored.

• Focused anditory attention. Initial research on focused auditory attention with the shadowing task suggested there was very limited processing of the unattended stimuli. However, there can be extensive processing of unattended stimuli. This is especially the case when the unattended stimuli are dissimilar to the attended ones. There has been a controversy between early- and late-selection theorists as to the location of a bottleneck in processing. Most of the evidence favours early-selection theories. However, there may be some flexibility in the stage of processing at which selection occurs.

• Focused visual attention. Focused visual attention resembles a zoom lens more than a spotlight, as the size of the visual field within focal attention varies as a function of task demands. However, attention is often directed to objects rather than to a given region in space in normals and in neglect and extinction patients. Focused visual attention is more flexible than is implied by the zoom-lens approach. Unattended visual stimuli are typically processed less thoroughly than attended ones, and this conclusion is supported by studies on event-related potentials. However, the use of sensitive measures indicates that normals and neglect patients often process the meaning of unattended visual stimuli. According to Treisman's feature integration theory, visual search typically involves a rapid initial parallel processing of features followed by a slower serial process in which features are combined to form objects. Visual search is not entirely parallel or serial, and searching for objects is typically faster and more efficient than is predicted by the theory. According to Posner, visual attention involves disengagement of attention from one stimulus, shifting of attention from one stimulus to another, and engagement of attention on the new stimulus.

• Divided attention. Dual-task performance depends on task similarity, practice, and task difficulty. There is a psychological refractory period even when the stimuli and responses involved differ greatly or when there is prolonged practice. This suggests that there is a bottleneck in processing, although extensive parallel processing is also possible. There is evidence for a general central capacity having limited processing powers, and also for modular theories with their emphasis on specific processing resources.

• Automatic processing. Several theorists have argued that practice leads to automatic processing. Automatic processes are fast, they do not reduce the capacity available for other tasks, and there is generally no conscious awareness of them. According to instance theory, increased knowledge about what to do with different stimuli is stored away with practice, and automaticity occurs when this information is retrieved very rapidly. Thus, automaticity is a memory phenomenon that depends on the relationship between encoding and retrieval.

• Action slips. Action slips occur as a result of attentional failure. Individuals run off sequences of highly practised and overlearned motor programmes. Attentional control is not needed while each programme is running, but is needed when there is a switch from one programme to another. Failure to attend at these choice points can lead to the wrong motor programme being activated, especially if it is stronger than the right one. As optimal performance requires frequent shifts between the presence and absence of attentional control, it is perhaps surprising that action slips are not more prevalent.

Business Correspondence

Business Correspondence

24 chapters on preparing to write the letter and finding the proper viewpoint how to open the letter, present the proposition convincingly, make an effective close how to acquire a forceful style and inject originality how to adapt selling appeal to different prospects and get orders by letter proved principles and practical schemes illustrated by extracts from 217 actual letter.

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