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Selective

The final function defined within attention is executive attention. Executive attention includes processes for monitoring and resolving conflicts that arise among internal processes. These processes include thoughts, feelings, and responses. The brain areas involved in this final and highest order of attentional process arc anterior cingulated. lateral ventral, prefrontal. and basal ganglia. The neurotransmitter most involved in the executive attention process is dopamine. Dysfunction within this system is associated with Alzheimer's disease, borderline personality disorder, and schizophrenia.

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Cognitive Neuroscientific Approaches to Attention and Consciousness

Spatial Neglect

Attentional Systems

Is attention a function of the entire brain. or is it a function of discrete attention-governing modules in the brain?

Posner ( 1995) has identified an anterior (frontward) attention system (attentional network) within the frontal lobe and a posterior (toward the rear) attention system within the parietal lobe. The anterior attention system becomes increasingly activated during tasks requiring awareness. An example would be tasks in which participants must atend to the meanings of words.

Spatial neglect or just neglect is an attentional dysfunction in which participants ignore the half of their visual field that is contralateral, on the opposite side, to the hemisphere of the brain that has a lesion. It is due mainly to unilateral lesions in the parietal lobes. Research reveals that the problem may be a result of the interaction of systems that mutually inhibit one another. When only one of the pair involved in the system is damaged, as is the case with neglect patients, patients become locked in to one side of the visual field. The reason is that the inhibition normally provided by the other half of the system is no longer working.

Posner and Rothbart (2007) completed a review of neuroimaging studies in the area of attention. What at first seemed like an unclear pattern of activation can be effectively organized into areas associated with the three subfunctions of attention. The researchers define these functions as alerting, orienting, and executive attention. The researchers organized the findings to describe each of these functions in terms of the brain areas involved, the neurotransmiters that modulate the changes. and the results of dysfunction within this system.

Alerting is defined as being prepared to attend to some incoming event. Alerting also includes the process of getting to this state of preparedness. The brain areas involved in alerting arc the superior parietal, temporal parietal junction, frontal eye field, and superior colliculus. The neurotransmitter that modulates alerting is acetylcholine. Dysfunction of the alerting system is related to attentional changes as we age and to ADHD.

The second function of attention is orienting. Orienting is defined as the selection of stimuli to attend to. The brain areas involved in the orienting function arc the locus coeruleus, right frontal. and parietal cortex. The modulating neurotransmitter for orienting is norephinephrine. Dysfunction within this system is related to autism.

Using Event-Related Potentials to Measure Attention

A Psychopharmacological Approach

An alternative way of studying attention in the brain is to focus on studying event-related potentials. They indicate minute changes in electrical activity in response to various stimuli.

Evaluates changes in attention and consciousness associated with various chemicals (e.g., neurotransmitters such as acetylcholine or GABA, hormones, and even central nervous system stimulants ["uppers"] or depressants ["downers"]. In addition, researchers study physiological aspects of attentional processes at a global level of analysis.

Consciousness of Complex Mental Processes

Attention Deficit Hyperactivity Disorder (ADHD)

First described by Dr. Heinrich Hoffman in 1845.

A second view is that people's access to their complex mental processes is not very good. In this view. people may think they know how they solve complex problems, but their thoughts arc frequently erroneous. According to Nisbett and Wilson, we typically are conscious of the products of our thinking, but only vaguely conscious, if at all, of the processes of thinking.

Three primary characteristics of ADHD

One view is that people have quite good access to

their complex mental processes. Simon and his colleagues, for example, have used protocol analysis in analyzing people's solving of problems. such as chess problems and so-called cryptarithmetic problems, in which one has to figure out what numbers substitute for letters in a mathematical computation problem. These investigations have suggested to Simon and his colleagues that people have quite good conscious

access to their complex information processes.

a. inattention

b. hyperactivity (i.e., levels of activity that exceed what ;s normally shown by children of a given age)

c. impulsiveness.

Children with the inattentive type of ADHD show several distinctive symptoms

1. They are easily distracted by irrelevant sights and sounds.

2. They often fail to pay attention to details.

3. They are susceptible to making careless mi stakes in

their work.

4. They often fail to read instructions completely or carefully.

5. They arc susceptible to forgetting or losing things they need for tasks, such as pencils or books.

6. They tend to jump from one incompleted task to another.

Three main types:

Change Blindness

1. predominantly hyperactive-impulsive

2. predominantly inattentive

3. combination of inattentiveness with hyperactivity and impulsiveness.

The inability to detect changes in objects or scenes that are being viewed.

Change blindness is not limited to visual information. The inability to detect a change can be observed in auditory and tactile stimuli. However, as in visual stimuli, a brief delay must be present between the original and changed stimuli.

These results suggest that people are much less astute in recognizing changes in their environments than we might expect. Even fairly blatant changes, such as the

identity of a person to whom we speak, may pass us by. When we admire Sherlock Holmes for his astuteness, we probably give him too little credit. In the fictional detective stories in which he plays a role, he notices extremely unobvious things. Often we tend not to notice even things that arc obvious.

Divided Attention

Neisser and Becklen hypothesized that improvements in performance would have occurred eventually as a result of practice. They also hypothesized that the performance of multiple tasks was based on skill resulting from practice. They believed it not to be based on special cognitive mechanisms.

The following year, investigators used a dual-task paradigm to study divided attention during the simultaneous performance of two activities. The dual-task paradigm involves two tasks (Task A and Task B) and three conditions (Task A only, Task B only. and both Tasks A and B). The idea was that the researchers would compare and contrast the latency (response time) and accuracy of performance in each of the three conditions.

Ulric Neisser

Robert Becklen

Spelke and colleagues' experiment

Studying Divided Attention

One widely used paradigm makes use of a simulation of the driving situation. Researchers had participants perform a tracking task. The participants had control of a joystick, which moved a cursor on a computer screen. The participants needed to keep the cursor in position on a moving target. At various times, the target would flash either green or red. If the color was green, the participants were to ignore the signal. If the color was red, however, the participants were to push a simulated brake. The simulated brake was a button on the joystick.

In one condition, participants did the task singly-that is, by itself. In another condition, participants were involved in a second task. This procedure created a dual-task situation. The participants either listened to a radio broadcast while doing the task or talked on a cell phone to an experimental confederate. Participants talked

roughly half the time and also listened roughly half the time. Two different topics were used to ensure that the results were not due to the topic of conversation.

Spelke and her colleagues suggested that these findings

showed that controlled tasks can be automatized so thar they consume fewer attentional resources. Further, two discrete controlled tasks may be automatized to function whether as a unit. These authors were quick to point out that the tasks do not, however, become fully automatic. For one thing, they continue to be intentional and

conscious. For another, they involve relatively high levels of cognitive processing.

An entirely different approach to studying divided attention has focused on extremely simple tasks that require speedy responses. When people try to perform two overlapping speeded tasks, the responses for one or both tasks are almost always slower. When a second task begins soon after the first task has Started, speed of performance usually suffers. The slowing resulting from simultaneous engagement in speeded tasks, as mentioned earlier in the chapter. is the PRP effect.

and Divided Attention

The Stroop Effect

John Ridley Stroop

■ An alternative explanation is that the output of a response occurs when the mental pathways for producing the response are activated sufficiently. In the Stroop test, the color word activates a cortical pathway for saying the word. In contrast, the ink-color name activates a pathway for naming the color. But the former pathway interferes with the latter. In this situation, it takes longer to gather sufficient strength of activation to produce the color,naming response and not the word-reading response.

The Stroop effect demonstrates the psychological difficulty in selectively attending to the color of the ink and trying to ignore the word that is printed with the ink of that color.

■ One explanation of why the Stroop test may be particularly difficult is that, for most adults, reading is now an automatic process. It is not readily subject to your conscious control. For that reason, you find it difficult intentionally to refrain from reading

and instead to concentrate on identifying the color of the ink, disregarding the word printed in that ink color.

Variations of the Stroop effect

■ number Stroop

■ directional Stroop

■ animal Stroop

■ emotional Stroop

Number Stroop

Emotional Stroop

In the number Stroop, number words are used. Thus, the word two might be written three times, two, two, two, and the participants be asked to count the number of words. As with the standard Stroop task, reading sometimes interferes with the counting task

One of the most extensively used Stroop variations is the emotional Stroop. In this task, the standard task is modified so that the color words are replaced with either emotional or neutral words. Participants arc asked to name the colors of the words. Researchers find that there is a longer delay in color naming for emotional words as compared with neutral words. These findings suggest that the automatic reading of emotional words causes more interference than reading of neutral words.

Additional Considerations in Selective Attention

The Role of Task, Situation, and Person Variables

Nature of the task

Overall arousal

Specific interest in a target task and stimuli, compared with

interest in distracters

One may be fired, drowsy, or drugged, which may limit

attention. Being excited sometimes enhances it.

For example, it may be highly difficult, complex, or novel. Such tasks require more attentional resources than do easy, simple, or highly familiar tasks. Task difficulty particularly influences performance during divided attention.

Stage of processing at which attentional demands are needed

Amount of practice

in performing a given task or set of tasks

This stage may be before, during, or after some degree of perceptual processing.

Related to this is the skill of utilizing attentional resources for a task or tasks. Increased practice and skill enhance attention.

Attentional-Resource Theories of Selective Attention

Attentional-resource theories help to explain how we can perform more than one attention-demanding task at a time. They posit that people have a fixed amount of attention that they can choose to allocate according

to what the task requires.

Filter and Bottleneck Theories of Selective Attention

■ Filter-blocks some of the of the information going through and selects only a part of the total information to pass through to the next stage.

■ Bottleneck-slows down information passing through.

Multimode Theory

Multimode theory proposes that attention is flexible. Selection of one message over another message can be made at any of various different points in the course of information processing.

Stage 3

Stage 2

Stage 1

The individual constructs semantic representations.

The representations of Stages 1 and 2 become conscious.

The individual constructs sensory representations of

stimuli.

Moray’s Selective Filter Model

Neisser's Synthesis

Ulric Neisser synthesized the early-filter and late-filter models and proposed that there are two processes governing attention:

■Moray found that even when participants ignore most other high-level (e.g., semantic) aspects of an unattended message, they frequently still recognize their names in an unattended ear. He suggested that the reason for this effect is that powerful, highly salient messages may break through the filter of selective attention. But other messages may not.

Preattentive Processes

Attentive, Controlled Processes

■To modify Broadbent's metaphor, one could say that, according to Moray, the selective filter blocks out most information at the sensory level. But some highly salient, or personally important, messages are so powerful that they burst through the filtering mechanism.

These automatic processes are rapid and occur in parallel. They can be used to notice only physical sensory characteristics of the unattended message. But they do not discern meaning or relationships.

These processes occur later. They are executed serially and consume time and attentional resources, such as working memory. They also can be used to observe relationships among features. They serve to synthesize fragments into a mental representation of an object.

Basic Paradigms for Studying Selective Attention

■ Cocktail Party Problem

- the process of tracking one conversation in the face of the distraction of other conversations.

- proposed by Colin Cherry

►Shadowing- participant listen to two different messages and is required to repeat back only one of the messages as soon as possible after he/she hear it.

Dichotic Presentation-different messages to each ear

Binaural Presentation-the same messages to both ears

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