Attention Enables People to Pick

Attention enables people to pick an amalgam of information and data and give it priority for meaning extraction or processing. Key to the process of perception is emotionally arousing stimuli, which gives an individual contextual information paramount to reacting to changes in the environment. A fearful face or loud noise in a person's environment, for example, tells them to increase their attention because of possible danger. In many rapid serial visual presentation experiments, the second of two stimuli presented in quick succession is often not detected. This phenomenon is known as attentional blink. When the second stimulus is emotionally arousing, to be sure, it is more likely to be seen. Oftentimes, attention is a matter of outlook. In recent experiments, eyesight was definitively improved when people were induced to believe that they could see very well. Such beliefs enhanced visual clarity. These findings support long-held evidence that visual perception is not only dependent on relaying information from eyes to the brain, but, also, on experience-based assumptions about what is perceivable in particular situations. (Deutsch 83)

In noisy situations, such as at a cocktail party, we rarely think about how it is we single-out one voice for perception. For a long time, researchers have not understood how the human brain filters out a single conversation from a web of intercrossing conversations.

Colin Cherry, a British cognitive scientist, called this phenomenon the "cocktail party effect" in the 1950s. Today, scientists contend that the secondary auditory cortex, which is located in the temporal lobe at the side of the head, does much of the untangling. Alexander Gutschalk, of the Ruprecht-Karl University of Heidelberg in German along with his team, hooked up subjects to a Magnetoencephalography (MEG) imager. The researchers then played the subjects a sound file containing many randomly repeating tones across many frequencies. Within the track was a regularly repeating tone. The subjects were asked to press a button when they heard the regular tone. Once the subjects were aware of the regular tone, activity greatly increased in the secondary audio cortex. "In fact, we see the activity even before the subject presses the key, which is interesting," says Gutschalk.

(Phelps 290)

Many factors come into play regarding how we divide out attention. If we perceive two people are talking directly to us, considering the cues we receive from stimuli, it is more difficult for us to concentrate on one task. In a sea of conversation, none of which directly oriented at us, it becomes easier to pick and choose. When something is emotionally riveting, furthermore, we can get lost it. If somebody was to try and get our attention in such a moment, we might not even notice the stimuli meant for us, and perceived by our subconscious.

Evidence suggests that attention can concurrently isolate multiple locations for focus. Still not clear, however, is if this ability depends on continuous allocation of attention to the different targets, referred to as a "parallel" strategy, or if attention changes rapidly between the targets, known as a temporal "sampling" strategy. but, either way, both techniques can explain the "set size effects," whereby, with each additional attended item, cognitive attention and performance decreases.

William James wrote of attention in his textbook, Principles of Psychology: (Broadbent 190)

"Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed and scatterbrained state which in French is called distraction, and Zerstreutheit in German."

The process demonstrated in the cocktail party effect revolved around sound localization. Time-and-level differences between both ears, timing analysis, correlation analysis, spectral information and pattern matching are the processes which constitute this ability. Animals also use ear movement in order to localize sound. Neurons sensitive to sound level differences are excited by stimulation of a certain ear more than another. This depends on the strength of the two inputs, which depends on the sound intensities at the ears. (Broadbent 193)