Attention
Attention or focus, is the concentration of awareness on some phenomenon to the exclusion of other stimuli.[1] It is a process of selectively concentrating on a discrete aspect of information, whether considered subjective or objective. William James (1890) wrote that "Attention 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."[2] Attention has also been described as the allocation of limited cognitive processing resources.[3] Attention is manifested by an attentional bottleneck, in terms of the amount of data the brain can process each second; for example, in human vision, only less than 1% of the visual input data (at around one megabyte per second) can enter the bottleneck,[4][5] leading to inattentional blindness.
This article is about the psychological concept of attention. For other uses, see Attention (disambiguation).
Attention remains a crucial area of investigation within education, psychology, neuroscience, cognitive neuroscience, and neuropsychology. Areas of active investigation involve determining the source of the sensory cues and signals that generate attention, the effects of these sensory cues and signals on the tuning properties of sensory neurons, and the relationship between attention and other behavioral and cognitive processes, which may include working memory and psychological vigilance. A relatively new body of research, which expands upon earlier research within psychopathology, is investigating the diagnostic symptoms associated with traumatic brain injury and its effects on attention. Attention also varies across cultures.[6]
The relationships between attention and consciousness are complex enough that they have warranted philosophical exploration. Such exploration is both ancient and continually relevant, as it can have effects in fields ranging from mental health and the study of disorders of consciousness to artificial intelligence and its domains of research.
Contemporary definition and research[edit]
Prior to the founding of psychology as a scientific discipline, attention was studied in the field of philosophy. Thus, many of the discoveries in the field of attention were made by philosophers. Psychologist John B. Watson calls Juan Luis Vives the father of modern psychology because, in his book De Anima et Vita (The Soul and Life), he was the first to recognize the importance of empirical investigation.[7] In his work on memory, Vives found that the more closely one attends to stimuli, the better they will be retained.
By the 1990s, psychologists began using positron emission tomography (PET) and later functional magnetic resonance imaging (fMRI) to image the brain while monitoring tasks involving attention. Considering this expensive equipment was generally only available in hospitals, psychologists sought cooperation with neurologists. Psychologist Michael Posner (then already renowned for his influential work on visual selective attention) and neurologist Marcus Raichle pioneered brain imaging studies of selective attention.[8] Their results soon sparked interest from the neuroscience community, which until then had been focused on monkey brains. With the development of these technological innovations, neuroscientists became interested in this type of research that combines sophisticated experimental paradigms from cognitive psychology with these new brain imaging techniques. Although the older technique of electroencephalography (EEG) had long been used to study the brain activity underlying selective attention by cognitive psychophysiologists, the ability of the newer techniques to measure precisely localized activity inside the brain generated renewed interest by a wider community of researchers. A growing body of such neuroimaging research has identified a frontoparietal attention network which appears to be responsible for control of attention.[9]
A definition of a psychological construct forms a research approach to its study. In scientific works, attention often coincides and substitutes the notion of intentionality due to the extent of semantic uncertainty in the linguistic explanations of these notions' definitions. Intentionality has in turn been defined as "the power of minds to be about something: to represent or to stand for things, properties and states of affairs".[10] Although these two psychological constructs (attention and intentionality) appear to be defined by similar terms, they are different notions. To clarify the definition of attention, it would be correct to consider the origin of this notion to review the meaning of the term given to it when the experimental study on attention was initiated. It is thought that the experimental approach began with famous experiments with a 4 x 4 matrix of sixteen randomly chosen letters – the experimental paradigm that informed Wundt's theory of attention.[11] Wundt interpreted the experimental outcome introducing the meaning of attention as "that psychical process, which is operative in the clear perception of the narrow region of the content of consciousness."[12] These experiments showed the physical limits of attention threshold, which were 3-6 letters observing the matrix during 1/10 s of their exposition.[11] "We shall call the entrance into the large region of consciousness - apprehension, and the elevation into the focus of attention - apperception."[13] Wundt's theory of attention postulated one of the main features of this notion that attention is an active, voluntary process realized during a certain time.[11] In contrast, neuroscience research shows that intentionality may emerge instantly, even unconsciously; research reported to register neuronal correlates of an intentional act that preceded this conscious act (also see shared intentionality).[14][15] Therefore, while intentionality is a mental state (“the power of the mind to be about something”, arising even unconsciously), the description of the construct of attention should be understood in the dynamical sense as the ability to elevate the clear perception of the narrow region of the content of consciousness and to keep in mind this state for a time. The attention threshold would be the period of minimum time needed for employing perception to clearly apprehend the scope of intention. From this perspective, a scientific approach to attention is relevant when it considers the difference between these two concepts (first of all, between their statical and dynamical statuses).
The growing body of literature shows empirical evidence that attention is conditioned by the number of elements and the duration of exposition. Decades of research on subitizing have supported Wundt's findings about the limits of a human ability to concentrate awareness on a task.[16][17][18][19][20] A significant inference from the Wundtian approach to the study of attention: the scope of attention is related to cognitive development.[21] As the mind grasps more details about an event, it also increases the number of reasonable combinations within that event, enhancing the probability of better understanding its features and particularity.[21] For example, three items in the focal point of consciousness have six possible combinations (3 factorial), and four items have 24 (4 factorial) combinations. This number of combinations becomes significantly prominent in the case of a focal point with six items with 720 possible combinations (6 factorial).[21] Empirical evidence suggests that the scope of attention in young children develops from two items in the focal point at age up to six months to five or more items in the focal point at age about five years.[21]
Neuropsychological model[edit]
In the twentieth century, the pioneering research of Lev Vygotsky and Alexander Luria led to the three-part model of neuropsychology defining the working brain as being represented by three co-active processes listed as Attention, Memory, and Activation. A.R. Luria published his well-known book The Working Brain in 1973 as a concise adjunct volume to his previous 1962 book Higher Cortical Functions in Man. In this volume, Luria summarized his three-part global theory of the working brain as being composed of three constantly co-active processes which he described as the; (1) Attention system, (2) Mnestic (memory) system, and (3) Cortical activation system. The two books together are considered by Homskaya's account as "among Luria's major works in neuropsychology, most fully reflecting all the aspects (theoretical, clinical, experimental) of this new discipline."[31] The product of the combined research of Vygotsky and Luria have determined a large part of the contemporary understanding and definition of attention as it is understood at the start of the 21st-century.
Simultaneous[edit]
Simultaneous attention is a type of attention, classified by attending to multiple events at the same time. Simultaneous attention is demonstrated by children in Indigenous communities, who learn through this type of attention to their surroundings.[46] Simultaneous attention is present in the ways in which children of indigenous backgrounds interact both with their surroundings and with other individuals. Simultaneous attention requires focus on multiple simultaneous activities or occurrences. This differs from multitasking, which is characterized by alternating attention and focus between multiple activities, or halting one activity before switching to the next.
Simultaneous attention involves uninterrupted attention to several activities occurring at the same time. Another cultural practice that may relate to simultaneous attention strategies is coordination within a group. Indigenous heritage toddlers and caregivers in San Pedro were observed to frequently coordinate their activities with other members of a group in ways parallel to a model of simultaneous attention, whereas middle-class European-descent families in the U.S. would move back and forth between events.[6][47] Research concludes that children with close ties to Indigenous American roots have a high tendency to be especially wide, keen observers.[48] This points to a strong cultural difference in attention management.
Alternative topics and discussions[edit]
Overt and covert orienting[edit]
Attention may be differentiated into "overt" versus "covert" orienting.[49]
Overt orienting is the act of selectively attending to an item or location over others by moving the eyes to point in that direction.[50] Overt orienting can be directly observed in the form of eye movements. Although overt eye movements are quite common, there is a distinction that can be made between two types of eye movements; reflexive and controlled. Reflexive movements are commanded by the superior colliculus of the midbrain. These movements are fast and are activated by the sudden appearance of stimuli. In contrast, controlled eye movements are commanded by areas in the frontal lobe. These movements are slow and voluntary.
Covert orienting is the act of mentally shifting one's focus without moving one's eyes.[23][50][51] Simply, it is changes in attention that are not attributable to overt eye movements. Covert orienting has the potential to affect the output of perceptual processes by governing attention to particular items or locations (for example, the activity of a V4 neuron whose receptive field lies on an attended stimuli will be enhanced by covert attention)[52] but does not influence the information that is processed by the senses. Researchers often use "filtering" tasks to study the role of covert attention of selecting information. These tasks often require participants to observe a number of stimuli, but attend to only one.
The current view is that visual covert attention is a mechanism for quickly scanning the field of view for interesting locations. This shift in covert attention is linked to eye movement circuitry that sets up a slower saccade to that location.[53]
There are studies that suggest the mechanisms of overt and covert orienting may not be controlled separately and independently as previously believed. Central mechanisms that may control covert orienting, such as the parietal lobe, also receive input from subcortical centres involved in overt orienting.[50] In support of this, general theories of attention actively assume bottom-up (reflexive) processes and top-down (voluntary) processes converge on a common neural architecture, in that they control both covert and overt attentional systems.[54] For example, if individuals attend to the right hand corner field of view, movement of the eyes in that direction may have to be actively suppressed.
Covert attention has been argued to reflect the existence of processes "programming explicit ocular movement".[55] However, this has been questioned on the grounds that N2, "a neural measure of covert attentional allocation—does not always precede eye movements".[56] However, the researchers acknowledge, "it may be impossible to definitively rule out the possibility that some kind of shift of covert attention precedes every shift of overt attention".[56]
Exogenous and endogenous orienting[edit]
Orienting attention is vital and can be controlled through external (exogenous) or internal (endogenous) processes. However, comparing these two processes is challenging because external signals do not operate completely exogenously, but will only summon attention and eye movements if they are important to the subject.[50]
Exogenous (from Greek exo, meaning "outside", and genein, meaning "to produce") orienting is frequently described as being under control of a stimulus.[57] Exogenous orienting is considered to be reflexive and automatic and is caused by a sudden change in the periphery. This often results in a reflexive saccade. Since exogenous cues are typically presented in the periphery, they are referred to as peripheral cues. Exogenous orienting can even be observed when individuals are aware that the cue will not relay reliable, accurate information about where a target is going to occur. This means that the mere presence of an exogenous cue will affect the response to other stimuli that are subsequently presented in the cue's previous location.[58]
Several studies have investigated the influence of valid and invalid cues.[50][59][60][61] They concluded that valid peripheral cues benefit performance, for instance when the peripheral cues are brief flashes at the relevant location before the onset of a visual stimulus. Posner and Cohen (1984) noted a reversal of this benefit takes place when the interval between the onset of the cue and the onset of the target is longer than about 300 ms.[62] The phenomenon of valid cues producing longer reaction times than invalid cues is called inhibition of return.
Endogenous (from Greek endo, meaning "within" or "internally") orienting is the intentional allocation of attentional resources to a predetermined location or space. Simply stated, endogenous orienting occurs when attention is oriented according to an observer's goals or desires, allowing the focus of attention to be manipulated by the demands of a task. In order to have an effect, endogenous cues must be processed by the observer and acted upon purposefully. These cues are frequently referred to as central cues. This is because they are typically presented at the center of a display, where an observer's eyes are likely to be fixated. Central cues, such as an arrow or digit presented at fixation, tell observers to attend to a specific location.[63]
When examining differences between exogenous and endogenous orienting, some researchers suggest that there are four differences between the two kinds of cues:
History of the study[edit]
Philosophical period[edit]
Psychologist Daniel E. Berlyne credits the first extended treatment of attention to philosopher Nicolas Malebranche in his work "The Search After Truth". "Malebranche held that we have access to ideas, or mental representations of the external world, but not direct access to the world itself."[7] Thus in order to keep these ideas organized, attention is necessary.[120] Otherwise we will confuse these ideas. Malebranche writes in "The Search After Truth", "because it often happens that the understanding has only confused and imperfect perceptions of things, it is truly a cause of our errors.... It is therefore necessary to look for means to keep our perceptions from being confused and imperfect. And, because, as everyone knows, there is nothing that makes them clearer and more distinct than attentiveness, we must try to find the means to become more attentive than we are".[121] According to Malebranche, attention is crucial to understanding and keeping thoughts organized.
Philosopher Gottfried Wilhelm Leibniz introduced the concept of apperception to this philosophical approach to attention. Apperception refers to "the process by which new experience is assimilated to and transformed by the residuum of past experience of an individual to form a new whole."[122] Apperception is required for a perceived event to become a conscious event. Leibniz emphasized a reflexive involuntary view of attention known as exogenous orienting. However, there is also endogenous orienting which is voluntary and directed attention. Philosopher Johann Friedrich Herbart agreed with Leibniz's view of apperception; however, he expounded on it in by saying that new experiences had to be tied to ones already existing in the mind. Herbart was also the first person to stress the importance of applying mathematical modeling to the study of psychology.[7]
Throughout the philosophical era, various thinkers made significant contributions to the field of attention studies, beginning with research on the extent of attention and how attention is directed. In the beginning of the 19th century, it was thought that people were not able to attend to more than one stimulus at a time. However, with research contributions by Sir William Hamilton, 9th Baronet this view was changed. Hamilton proposed a view of attention that likened its capacity to holding marbles. You can only hold a certain number of marbles at a time before it starts to spill over. His view states that we can attend to more than one stimulus at once. William Stanley Jevons later expanded this view and stated that we can attend to up to four items at a time.[123]
1860–1909[edit]
This period of attention research took the focus from conceptual findings to experimental testing. It also involved psychophysical methods that allowed measurement of the relation between physical stimulus properties and the psychological perceptions of them. This period covers the development of attentional research from the founding of psychology to 1909.
Wilhelm Wundt introduced the study of attention to the field of psychology. Wundt measured mental processing speed by likening it to differences in stargazing measurements. Astronomers in this time would measure the time it took for stars to travel. Among these measurements when astronomers recorded the times, there were personal differences in calculation. These different readings resulted in different reports from each astronomer. To correct for this, a personal equation was developed. Wundt applied this to mental processing speed. Wundt realized that the time it takes to see the stimulus of the star and write down the time was being called an "observation error" but actually was the time it takes to switch voluntarily one's attention from one stimulus to another. Wundt called his school of psychology voluntarism. It was his belief that psychological processes can only be understood in terms of goals and consequences.
Franciscus Donders used mental chronometry to study attention and it was considered a major field of intellectual inquiry by authors such as Sigmund Freud. Donders and his students conducted the first detailed investigations of the speed of mental processes. Donders measured the time required to identify a stimulus and to select a motor response. This was the time difference between stimulus discrimination and response initiation. Donders also formalized the subtractive method which states that the time for a particular process can be estimated by adding that process to a task and taking the difference in reaction time between the two tasks. He also differentiated between three types of reactions: simple reaction, choice reaction, and go/no-go reaction.
Hermann von Helmholtz also contributed to the field of attention relating to the extent of attention. Von Helmholtz stated that it is possible to focus on one stimulus and still perceive or ignore others. An example of this is being able to focus on the letter u in the word house and still perceiving the letters h, o, s, and e.
One major debate in this period was whether it was possible to attend to two things at once (split attention). Walter Benjamin described this experience as "reception in a state of distraction." This disagreement could only be resolved through experimentation.
In 1890, William James, in his textbook The Principles of Psychology, remarked: