What is the history of research into attention? - BulletPoints 1

• In daily life, people are exposed to different stimuli. These stimuli often evoke conflicting responses: some are relevant to our goals, while some are totally irrelevant. Studies of attention look into how people coordinate these various stimuli to achieve their desired goals. The study of attention plays an important role in cognitive psychology and cognitive neuroscience. Since the emergence of psychology, people have been studying attention. Ribot and Titchener were two of those researchers. There are five distinct periods in the historical overview of research on attention.
• Important philosophers were:
• Vives: mainly studied attention and memory;
• Malebranche: claimed that attention is needed to understand things;
• Leibniz: came up with the term "apperception", which refer to the processes that are needed to consciously perceive an event;
• Hamilton: claimed that a person can handle more than one thing at the same time;
• Herbart: developed mathematical models for research

James suggested several ways in which attention could be classified:

• Attention is directed either to a) physical or b) non-physical objects (ideas)
• Attention is either a) immediate or b) derived
• Attention may be either a) passive, reflex, non-voluntary, effortless (exogenous control) or  b) active and voluntary (endogenous control)

What is the process of information processing in the brain? - BulletPoints 2

• The information processing approach focuses on the processes by which information in a stimulus is translated to a response. There have been various techniques developed to gain insight into their nature, such as:
• Observation: stimulus identification;
• Decision making and response selection;
• Programming of response and execution.
• All processes depend on the amount of energy, capacity or mental resources devoted to processing. The arousal level can be seen as a mental resource. Since 1900, research has been conducted into the relationship between arousal levels and performance. Yerkes and Dodson's Law states that performance is an inverted U-shape function of arousal, with optimal arousal levels being lower when the task is more difficult. 
• The most commonly used measures of performance are reaction time and accuracy.

Which visual stimuli are processed by the brain and how? - BulletPoints 3

• Attention is needed for perception. Since we only have a limited capacity to perceive, attention ensures that we do not have to process an abundance of information. In addition, we need attention to actually attribute all characteristics of a certain object to that object. If we have to process all the characteristics of many objects at the same time, we no longer know what belongs to what (this is called the binding problem).
• Attention can indeed change it's location like a spotlight. The time required for this does not appear to depend on the distance. However, changing the focus takes time. It turns out that attention only focuses on a new place once the old focus has been completely released. So you could say that the spotlight turns off and on. The ability to shift attention from one thing to another depends on the type of object.
• The spotlight theory claims that everything that is in the spotlight gets attention. However, this does not have to be the case. It appears that empty spaces are processed differently compared objects, despite the fact that they are both in the spotlight. 

How do different senses or modalities work together? - BulletPoints 4

• We all know the experience of following two conversations at the same time. For example, when you are at a party and you have a conversation with someone, but then you hear your name in another conversation. It can also be the case that you want to focus on one conversation and you try to ignore other conversations, such as when you want to watch a movie. In 1950, researchers developed the dichotic listening paradigm. In this paradigm, two separate sources of information are presented to the two ears of the listener. For example, someone gets to hear a list of spoken numbers in one ear, and a list of spoken letters in the other ear. This task has often been used to study the limits of attention in selecting information.
• Dividing attention among different messages appears to be difficult for many people. For example, can you listen to someone on the phone and listen to the weather forecast on television at the same time? Probably not.
• Whether people can divide their attention, can be studied using the split-span technique. In such an experiment, the researchers split a list of numbers in two and one half is provided to the right ear and the other half to the left ear. From these studies, you can conclude that selection takes place early on the basis of characteristics such as the location and pitch.
• When different senses or modalities compete with each other, it appears that especially the eyes or the visual system wins. This is called visual dominance. An example of this is when you are sitting in one train and you watch another train which is moving. Then, you think that you are moving yourself, even though you do not feel that you are moving. So, your eyes determine what you perceive at that moment. Even if you see and hear a light and a tone at the same time, many people only respond to the light. In another experiment, people actually think that their hands are shaking, because they are watching shaking hands. It should be noted that there is not always visual dominance is not always dominant.

When and how does inhibition of attention take place? - BulletPoints 5

• You can improve your performance on a task in two ways. First, you can focus on what you have to do and try do this better. Second, you can focus on what you should not do. This chapter deals with the latter: the suppression of irrelevant information and the inhibition of inappropriate actions. There are different ways to inhibit information processing.
• The Simon effect refers to the finding that responses are faster when the stimulus appears on the same side as the assigned response than when it does not. Like the Stroop effect, the Simon effect has to do with the inability to ignore irrelevant information. Thus, this effect shows that it is not necessary that the relevant and irrelevant dimensions of the stimuli are related in order for interference to occur. 
• Whether the stimulus is on the left or right is therefore useless information, but it appears that this information has an influence on the response. People respond slower when the location of the stimulus and the button are incongruent. 
• If you focus your attention on a certain place, objects viewed in that place will be processed faster. There are two different types of ways to focus, direct or select your attention. For example, using exogenous hints or endogenous hints or cues. Both lead to faster perception, but exogenous hints can also lead to inhibition of return. For example, people are slower at detecting a target at an exogenously cued location when there is more than 300 ms between the presentation of the cue and the presentation of the target. So, after an interval of 300 ms, responses to targets at a cued location are often slower than responses to objects at uncued locations. 

How can we divide our attention? - BulletPoints 6

• Researchers claim that attention strategies are limited by two factors. These factors are the cognitive strategies that someone uses and the goals of the person. Behavior is determined by cognitive strategies. These cognitive strategies can be divided into two components. The first component is a top-down process that determines which strategy is chosen. Top-down processes are based on a payoff rule. The other component is a bottom-up process that directs behavior based on information received. These two components are beautifully illustrated by a study conducted by Seagull and Gopher with pilots. Pilots were given the choice to either pay attention only to the rocks or to a larger area, so that other hazards could also be seen (top-down). Whenever there was a danger, they had to shift their attention. So, what was on display depended on their strategy. The bottom-up process took place when a rock suddenly appeared, forcing the pilot to steer the other way.
• To achieve goals in your life, you often have to reach smaller goals first called subgoals, first. So, you have to take several steps to achieve your goal. To achieve your goals, you are largely dependent on your attention. Your memory also plays an important role. If you intend to do something later, you should not forget this. A number of studies have been carried to look at attention when trying to achieve a goal. The procedural frame hypothesis states that people are better able to control their actions if they have figured out in advance what they want to do. So, they create a kind of mental step-by-step plan for themselves. Like this, they can process certain information related to their goals, faster. Others have also studied whether having a plan improves performance. The result is that people indeed act faster if they know what to do. However, knowing how to do it does not lead to increased performance.
• If you have to perform an action twice with certain stimuli, it appears that your reaction for the second response is slower when the stimuli followed each other quickly. This effect is called the 'psychological refractory period' effect (PRP). Researchers used to think that this was due to the fact that neurons became insensitive, hence the name. However, this idea has been proven false. 
• Another characteristic of the response-selection bottleneck model is that response-selection processing is all-or-none. As long as response selection is being performed for one task, it cannot be performed for the other. An alternative view is that although the capacity to perform response selection is limited, it is not all-or-none. According to this resource- or capacity-sharing view, the limited capacity resources required for response selection can be allocated to task 1 and task 2 in graded amounts. 

What does memory have to do with attention? - BulletPoints 7

• The short-term memory is also referred to as the working memory. This is because it not only stores information, but is also relevant for undertaking actions. The working memory consists of 3 components: the 'visuo-spatial sketchpad', the 'phonological loop' and the 'central executive'. The first two components are seen as 'slaves' of the last component, which processes and coordinates all incoming information.
• In the visuo-spatial sketchpad, spatial information is stored. This information is only used when a task involves the spatial information of something. It is suggested that there is a relationship between the processes that hold representations in the working memory and processes that select spatial attention. People can retrieve objects more quickly via the working memory that were visible in a place that they had given attention to. This relationship is also demonstrated using brain imaging techniques.
• It seems that our senses do their best to provide us with a stable picture of the world around us. The 'change blindness' effect shows that we actually have much less information at our disposal than we think we do. Change blindness occurs when people view an image or video, and then something changes in this video or image. People are often not aware of the change: they are blind for it. It appears that change blindness mainly occurs for things that were not focused on. It also appears that it is easier to see changes if the objects are in the center of the field of view. However, even if attention is focused on an object, this does not guarantee that the change will be seen. For a real-life experiment, go to YouTube and search for the Monkey Business video.

How can research into attention be applied? - BulletPoints 8

• One important area in the study of attention, is that of automation. Because of technological advances, many tasks can be automated. So, previously performed tasks by an operator are now performed by a mechanical system. A benefit of automation is that it reduces the attentional and cognitive demands placed on the operator, by allowing actions to occur, and potential problems to be detected, without requiring operator intervention. Another benefit is that systems can be programmed to adapt to the behaviors of specific users. There are also some negative sides to automation. Since the operator must input information into the automated system, this can lead to errors during information entry. An example of such an error is mode error, in which the interface has several modes for information entry and the operator mistakenly enters information thinking that one mode is in effect, while actually another mode is. Another negative point of automation is that operators may be "out of loop", and therefore do not fully understand the situation.
• Menus can also be designed to be adaptive in order to reduce search times for finding the desired item and to reduce movement time to select the item. These menus are called smart menus. These smart menus display only those commands from a menu that have been us most often and most recently. A drawback of smart menus is that the mapping of commands to specific locations is variable because the location depends on how many and which commands were used recently. So, practice and experience do not yield any benefits in performance.
• Grouping individual elements is very important for displays. When elements are grouped in an optimal manner, then performance will be better and the attentional demands will be lower. Grouping of displays can be accomplished by following the Gestalt principles for perceptual-organization:
• proximity: components in close spatial proximity tend to be grouped together
• similarity: components that are similar in appearance tend to be grouped together
• continuity: components that follow a continuous contour tend to be grouped together
• closure: gaps between contours tend to be filled in and;
• common fate: components that move in the same direction or at the same speed will tend to be grouped together

How can mental workload and situation awareness be measured?  - BulletPoints 9

• Mental workload is defined as the information processing demands which are imposed by the performance of cognitive tasks. Gopher and Donchin define mental workload as: "the difference between the capacities of the information-processing system that are required for task performance to satisfy expectations and the capacity available at any given time".
• Three different effects serve as proof for that there are multiple resources of attention:
• ' Difficulty insensitivity': this refers to the fact that allocating more resources to one of two tasks does not always hurt performance on the other one.
• ' Structural alteration effects': this refers to changing the structure of a task without changing its difficulty.
• ' Perfect time sharing': this is not possible according to the one-source model. But it appears to be possible. Two tasks that influence each other can be performed simultaneously without loss of attention (which is thus called perfect time-sharing).
• One way to assess the mental workload imposed by a task is to simply measure some aspect or aspects of task performance. If the workload becomes too high, the performance decreases. You can measure workload with 'dual' or 'secondary' tasks. These are tasks in which two tasks must be performed. By manipulating some components of the workload in the second task, you can measure the differences in performance. An example of this is a probe-reaction-time-task. In this task, a warning signal is followed by the presentation of a letter. After a short interval, a second letter is presented and participants have to indicate whether the two letters were the same or different. There are large differences in reaction times depending on when the probe is presented. The reaction times are the longest when the probe is presented around the time that the second letter is presented. This leads to the conclusion that response-selection processes require more general attentional resources than encoding or preparatory processing.
• Being aware of the environment ensures that you can still make the right decisions in a constantly changing environment. If you miss certain information from the environment, this is a sign that you lose your awareness of the environment. With this awareness you can therefore keep an eye on your environment. This awareness is supported by attention, the working memory and the long-term memory. Mental stress and awareness of the environment are two independent concepts. Taxing mental processes does not necessarily mean a reduction in consciousness and vice versa.

Which individual differences are important for attention? - BulletPoints 10

• How well people are able to control, select or direct their attention may have to do with intelligence. Intelligence underlies cognitive actions and mental speed during information processing. Intelligent people solve problems more efficiently. This has been studied with the use of PET scans, which show that intelligent people convert less glucose when they have to solve a problem. Another way to measure information speed processing efficiency is by making use of inspection time tests. These tests measures the minimum time that people need to solve a problem. So, it looks at how much time people to answer a question or solve a problem. According to some researchers, this inspection time reflects the mental processing and the speed or efficiency of brain activity. Others disagree, because if you control for attention, the relationship between inspection time and IQ decreases. Nevertheless, IQ is negatively correlated with inspection time. So the longer the time required, the lower the IQ.
• During the day, your body temperature varies and this temperature is related to the ability to focus or concentrate. Tasks which require minimal effort from the short-term memory are best performed later in the day. Tasks which require large short-term memory efforts are best performed at the beginning of the day. It appears that this morning benefit is not only related to alertness. Some claim that you also apply different cognitive strategies at different times of the day. Folkard and Monk claim that it is best to perform mathematical work in the morning and do other work in the evening. 
• The cognitive capacity of children changes dramatically during childhood. Children are more sensitive to distractions compared to adults. When children are 8 years old, the ability to focus or increase their attention is not fully developed. Recent studies show that children particularly struggle to focus their attention efficiently when the observation load is low (one or two items on a screen). However, if the observation load is high (many items on the screen), it appears that children can concentrate equally well compared to adults. Selective attention must also develop during childhood. Children of 10 year of age, are already much better at compared to children of 7 years old. 

What is the cognitive neuroscience of attention? - BulletPoints 11

• The techniques used by cognitive neuroscience have already been described in Chapter 2. The most important are ERPs, PETs and fMRIs. ERPs are mainly used to analyze temporary processes. FMRIs are used to determine the exact location of brain activity during actions. It can also be used to determine how different areas are connected to each other. In addition to these techniques, behavioral techniques such as reaction time measurements are often applied.
• Some processes take place without attention. Neisser called these processes 'preattentive processes'. Another common name is automatic processes. With the use of behavioral measurements, only the consequences of these processes can be measured. With the help of ERPs, the changes in an attention process can be measured. If people suddenly have to shift their attention on something new or unexpected, (for example during the oddball paradigm), then a balance (or equilibrium) is suddenly disturbed. This disturbed balance is called a mismatch. The difference between the ERPs of the mismatch and the ERPs of the equilibrium situation are compared, to determine what exactly happened during this process of shifting attention. If the mismatch occurs, that process is characterized by more negative voltage. This is called the 'mismatch negativity' (or MMN) and therefore occurs if something different or remarkable happens in the environment. 
• Knight and his colleagues have investigated the parts of the brain where attention is selected. A commonly used method to study the brain, is to examine patients with brain abnormalities or injuries. Deviations in certain brain areas are often associated with specific cognitive impairments. If you have a number of patients with the same brain disorders and the same cognitive disorders, you can make conclusions about where certain cognitive functions are located. 

Which disorders are related to attention? - BulletPoints 12

• Developmental disorders are cognitive or behavioral problems that present themselves in childhood. These disorders often have a genetic component. The most common developmental disorder is ADHD. Children with ADHD are unable to concentrate for a long time, are often restless and unorganized and have problems during social interactions with other children. Diagnosis of ADHD is sometimes difficult. Reports are needed from at least two environments (school and home, for example) to get to a diagnosis.
• Cerebrovascular diseases or strokes are a major cause of death and disability in the western world. There are two types of cerebrovascular disease: ischemic infarcts and cerebral bleedings or hemorrhages. The first is a result of a blocked artery, the second is a result of a burst blood vessel. Infarcts are more common than hemorrhages.
• Neglect is one of the most remarkable disorders caused by brain damage. In neglect, the patient does not acknowledge any stimulation from the side contralateral to the damaged hemisphere, and this symptom is not caused by problems in sensory or motor processes. Diagnosis of neglect is often difficult because other disorders are often present. Some patients also seem to neglect only one modality, which also complicates the diagnosis process. Simple pen and paper tests are used to get to a diagnosis. Patients with damage in their right hemisphere, often experience the worst symptoms. During drawing tests, patients with neglect often only draw half of the image. The other side, the side of their neglect, is not drawn (so, that side is neglected). However, this has nothing to do with an inability to see or an inability to draw: it only has to do with attention.