Attention
Attention is the concentration of awareness directed at some phenomenon while excluding others.
Across disciplines, the nature of this directedness is conceptualized in different ways. In cognitive psychology, attention is often described as the allocation of limited cognitive processing resources to a subset of information, thoughts, or tasks. In neuropsychology, attention is understood as a set of mechanisms by which sensory cues and internal goals modulate neuronal tuning and orient behavioral and cognitive processes.
Attention is not a unitary phenomenon but an umbrella term for multiple related processes, including selective attention, sustained attention, divided attention, and orienting. These processes are supported by distributed neural networks in frontal, parietal, and subcortical regions and are closely linked to working memory, executive functions, and consciousness.
Patterns of attention also vary across cultures, especially in how individuals attend to context versus focal objects and how children are guided to manage attention in everyday activities.
History
16th century
called Juan Luis Vives the father of modern psychology. In his book De Anima et Vita, Vives argued that the more closely one attends to stimuli, the better they are retained in memory.17th century
credited the first extended treatment of attention to Nicolas Malebranche, for whom attention is necessary "to keep our perceptions from being confused and imperfect".Gottfried Wilhelm Leibniz introduced the concept of apperception, referring 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". Apperception is required for a perceived event to become a conscious event. Leibniz emphasized a reflexive, involuntary view of attention, while also recognizing voluntary, directed attention.
Johann Friedrich Herbart agreed with Leibniz's view of apperception but emphasized that new experiences must be tied to those already existing in the mind. Herbart was also among the first to stress the importance of applying mathematical modeling to the study of psychology.
19th century
In the early 19th century, some theorists argued that people could not attend to more than one stimulus at a time. Later, William Hamilton likened attentional capacity to holding marbles: only a limited number can be held at once before they spill over. He proposed that more than one stimulus can be attended simultaneously. William Stanley Jevons expanded this view, suggesting that people can attend to up to four items at a time.Wilhelm Wundt introduced the systematic study of attention into psychology. He examined mental processing speed by analogy with differences in astronomical measurements: astronomers differed in the times they recorded for star transits, leading to the idea of a personal equation. Wundt argued that such differences reflect the time required to shift voluntary attention from one stimulus to another, rather than mere "observation error".
Franciscus Donders used mental chronometry to study attention, making it a major topic of investigation. Donders and his students measured the time required to identify a stimulus and select a response, developing the subtractive method to estimate the duration of specific mental processes. He distinguished between simple, choice, and go/no-go reaction times.
Hermann von Helmholtz also contributed to attention research, showing that it is possible to focus on one stimulus while still perceiving others. For example, one can fixate on the letter "u" in the word "house" while still perceiving "h", "o", "s", and "e".
A major debate of this period concerned whether it was possible to attend to two things at once. William James, in The Principles of Psychology, provided an influential definition:
James distinguished between sensorial attention and intellectual attention. He also differentiated immediate from derived attention and identified five major effects of attention: it influences perception, conception, discrimination, memory, and reaction time.
20th century
1910–1949
During the first half of the 20th century, explicit research on attention declined as behaviorism became dominant, leading some, such as Ulric Neisser, to claim that “there was no research on attention”. Nonetheless, important work was conducted. In 1927, A. T. Jersild published research on "mental set and shift," arguing that “the fact of mental set is primary in all conscious activity”. He showed that it took longer to complete a mixed list than a pure list, highlighting costs of task switching.In 1931, C. W. Telford identified the psychological refractory period, the delay in responding to a second stimulus when it closely follows a first, reflecting a refractory phase in the nervous system.
In 1935, John Ridley Stroop developed what became known as the Stroop effect, demonstrating that task-irrelevant stimulus information can strongly interfere with performance.
1950–1999
In the 1950s, attention research was revitalized as psychology underwent the "cognitive revolution", shifting away from strict positivism and behaviorism to include unobservable mental processes as legitimate objects of study.Modern experimental work began with investigations of the "cocktail party problem" by Colin Cherry in 1953. Cherry asked how people at a noisy party can attend to one conversation while ignoring others. He studied this through dichotic listening tasks, in which participants heard two simultaneous streams of speech through headphones and were asked to shadow one stream while ignoring the other. These paradigms were extended by Donald Broadbent and others.
By the 1990s, psychologists increasingly used positron emission tomography and functional magnetic resonance imaging to study attention in the brain. Because this equipment was typically housed in hospitals, psychologists collaborated with neurologists. Psychologist Michael Posner and neurologist Marcus Raichle pioneered imaging studies of selective attention.
The adoption of neuroimaging, alongside long-standing techniques such as electroencephalography, led to extensive research on the neural basis of attention. A growing body of work identified a frontoparietal attention network implicated in the control of attention.
Components
Attention is constrained by both the number of elements that can be processed and the duration of exposure. Experimental studies of attention began with Wundt’s findings. He suggested the scope of attention limited to about 3–6 items. Decades of research on subitizing have supported Wundt’s early findings regarding limits on the number of items that can be held in the focus of consciousness.The scope of attention is related to cognitive development. As the mind grasps more details about an event, it also increases the number of reasonable combinations among those elements, potentially enhancing understanding. For example, three items in the focus of consciousness have six possible combinations, four have 24, and six have 720. Empirical evidence suggests that the scope of attention in early development increases from about two items in the focal point at up to six months of age to five or more items by around five years.
Intentionality
A definition of a psychological construct shapes how it is studied. In scientific literature, attention sometimes overlaps with or is confused with intentionality, partly because of ambiguities in their linguistic definitions. Intentionality has been defined as "the power of minds to be about something: to represent or to stand for things, properties and states of affairs".Although attention and intentionality may be described in similar terms, they are distinct constructs. Historically, experimental studies of attention began with Wundt’s work using a 4 x 4 matrix of randomly chosen letters, which informed his theory of attention.
Wundt defined attention as “that psychical process, which is operative in the clear perception of the narrow region of the content of consciousness”. His experiments suggested limits to the attentional threshold. He distinguished between the entrance of content into consciousness and its elevation into the focus of attention. Wundt’s theory thus emphasized attention as an active, voluntary process unfolding over time.
In contrast, neuroscientific research suggests that intentionality can sometimes emerge rapidly and even unconsciously: neuronal correlates of an intentional act have been observed to precede conscious awareness of that intention.
From this perspective, intentionality can be described as a mental state, whereas attention is better understood dynamically as the process of elevating a subset of content into clear consciousness and sustaining it. The attention threshold may be viewed as the minimum time needed to clearly apprehend the intended content. Distinguishing these constructs is important for a precise scientific approach to attention.
Orienting
Orienting of attention refers to shifting focus across space, time, or modality. This can be driven by external or internal processes. External signals do not operate purely exogenously; they will capture attention and elicit eye movements primarily when they are behaviorally relevant to the observer.Exogenous orienting is typically described as stimulus-driven and automatic. It is often triggered by sudden changes in the periphery and may produce reflexive saccades. Because exogenous cues usually appear in peripheral locations, they are referred to as peripheral cues. Exogenous orienting can occur even when observers know the cue is uninformative: the mere presence of the cue in a location influences responses to subsequent stimuli presented there.
Many studies have examined the impact of valid and invalid cues. Typically, brief valid peripheral cues speed responses, but when the interval between cue and target exceeds ~300 ms, this benefit reverses. Posner and Cohen termed this reversal inhibition of return, in which responses to validly cued locations become slower than to invalid locations.
Endogenous orienting is the intentional allocation of attention to a location or object based on goals or instructions. Endogenous cues are often presented centrally and require interpretation and voluntary redirection of attention. These are therefore termed central cues.
Comparisons of exogenous and endogenous orienting have identified several differences:
- exogenous orienting is less affected by cognitive load than endogenous orienting;
- observers can ignore endogenous cues but not exogenous cues;
- exogenous cues typically have larger, more immediate effects; and
- expectations about cue validity influence endogenous orienting more strongly than exogenous orienting.
Top-down attention is mediated primarily by the frontal cortex and basal ganglia. As part of the executive functions, this system is closely related to working memory, conflict resolution, and inhibition.