{"history":[],"article":{"id":"4bd4c687-cd86-491e-a2bf-2d152cc67afb","title":"Eriksen flanker task","slug":"eriksen-flanker-task","content":":::summary\n:::\n\n# \nIn [cognitive psychology](https://bliptext.com/articles/cognitive-psychology), the **Eriksen flanker task** is a set of response inhibition tests used to assess the ability to suppress responses that are inappropriate in a particular [context](https://bliptext.com/articles/context-language-use).\nThe target is flanked by non-target stimuli which correspond either to the same directional response as the target (congruent flankers), to the opposite response (incongruent flankers), or to neither (neutral flankers).\nThe task is named for American psychologists Barbara.\nA. Eriksen & [Charles W. Eriksen](https://bliptext.com/articles/charles-w-eriksen), who first published the task in 1974, and for the flanker stimuli that surround the target.\nIn the tests, a directional response (usually left or right) is assigned to a central target [stimulus](https://bliptext.com/articles/stimulus-psychology).\nVarious forms of the task are used to measure information processing and [selective attention](https://bliptext.com/articles/selective-attention).\n\n# Procedure and method\nIn an Eriksen Flanker Task there are three types of stimuli used:\nIn the original test described by Eriksen and Eriksen in 1974, letter stimuli were used.\n**S**ubjects were instructed to make directional responses to certain letters, for example a right response could be associated to the letters **H** and **K**, and a left response to **S** and **C**.\nEach stimulus consisted of a set of seven letters, with the target stimulus placed in the central position.\nExamples of congruent stimuli would be **HHHKHHH** and **CCCSCCC**, where both the target stimulus and the flankers correspond to the same directional response.\nExamples of incongruent stimuli could be **HHHSHHH** and **CCCHCCC **, where the central target letter and the flankers correspond to opposite directional responses.\nChoice reaction times (CRTs or RTs) were then recorded and compared between congruent and incongruent conditions.\nOther variants of the Eriksen Flanker Task have used numbers, color patches, or arrows as stimuli.\nAlso, although most Eriksen Flanker Tasks show the flankers on the left and right of the target, they can also be placed above or below the target, or in other spatial orientations.\nThese examples all use an arbitrary mapping between the stimulus and the response.\nAnother possibility is to use a natural mapping, with arrows as stimuli.\nFor example, Kopp et al. (1994) used left and right arrows, with flanker stimuli above and below the target.\nThe flankers could be arrows pointing in the same direction as the target (congruent) the opposite direction (incongruent) or squares (neutral).\nMore commonly, flankers have been arranged in a horizontal array, as with letter stimuli, so **<<<<<** would be a congruent stimulus, **<<><<** an incongruent stimulus.\n# [Incongruent, congruent, and neutral stimuli represented by arrows. This is what a participant may see in a standard Eriksen Flanker Task | upload.wikimedia.org/wikipedia/commons/5/53/Congruent%2C///Incongruent%2C///and///Neutral///Flanker///stimuli.jpg]\n\n# Neurological basis\nWhen subjects participate in the Eriksen Flanker Task, the [anterior cingulate cortex](https://bliptext.com/articles/anterior-cingulate-cortex), or the ACC, is activated.\nThe ACC is a frontal brain structure responsible for a wide variety of [autonomic functions](https://bliptext.com/articles/autonomic-nervous-system).\nIt is observed to be more active in response to processing incongruent stimuli than congruent stimuli.\nIt is believed that the ACC may monitor the amount of conflict in an Eriksen Flanker trial.\nThen, that measured conflict is used to enhance the amount of control the participant has on the next trial.\nThus indicating that the more conflict presented on trial n, the more control expressed on trial n + 1.\nThis process leads to an interaction called the Gratton effect, which is the finding of a lower interference effect after an incongruent trial compared to the effect after a congruent trial.\nOn this first trial (trial n) the incongruent stimulus presented will lead to an increase in conflict detected by the ACC.\nOn trial n + 1, the increased conflict will lead to more control, causing the distracting, or flanker, stimuli to be more readily ignored.\n# [The Anterior Cingulate Cortex (ACC) is highlighted in yellow | upload.wikimedia.org/wikipedia/commons/1/10/MRI///anterior///cingulate.png]\n\n# Experimental findings\nThe flanker paradigm was originally introduced as a way of studying the cognitive processes involved in detection and recognition of targets in the presence of distracting information, or \"noise\".\nThe 1974 study found that CRT was significantly greater in incompatible than compatible conditions, a difference termed the flanker effect.\nEarlier work had used [visual search](https://bliptext.com/articles/visual-search), but because these tasks involve an active scan of the environment to identify the target stimulus, this experimental design made it difficult to separate the effects of distraction from the effects of the search process.\nIn the flanker paradigm, the position of the target is always known—there is no search process.\nNonetheless interference still occurs, so it can be studied independently of search mechanisms.\nEriksen and Schultz (1979) varied a number of features of the flanker tests, for example the size and contrast of the letters, or the use of forward or [backward masking](https://bliptext.com/articles/backward-masking).\nThey proposed a continuous flow model of perception in which information is processed in parallel for different stimulus elements, and accumulates over time until sufficient information is available to determine a response.\nMore recent work in this area has used neurophysiological measures such as [event-related potentials](https://bliptext.com/articles/event-related-potentials) or imaging techniques such as [fMRI](https://bliptext.com/articles/fmri).\n\n## Effects on performance\nA variety of factors have been shown to affect subject's performance on flanker tasks.\nAcute administration of [antihistamine](https://bliptext.com/articles/antihistamine) or [alcohol](https://bliptext.com/articles/alcohol-drug) severely impairs CRT in test measures, a deficit which Ramaekers et al. (1992) found to carry over to driving tests.\nThe study used an on-the-road driving tests, and several laboratory tests including the letter version of the Eriksen task to assess the effects of two antihistamines and alcohol on driving skills.\nBoth alcohol and the antihistamine [cetirizine](https://bliptext.com/articles/cetirizine) impaired performance in the test measures, and their effects were additive.\nThe non-sedating antihistamine [loratadine](https://bliptext.com/articles/loratadine) had no effect on any of the measures studied.\nThe arrow version of the flanker test has also been evaluated as a method of detecting impairment due to alcohol and drugs in drivers at the roadside, demonstrating the importance of selective attention skills to spatial abilities such as vehicle operation.\nVarious psychiatric and neurological conditions also affect performance on flanker tasks.\nWhile subjects with chronic schizophrenia performed similarly to control subjects on flanker tasks of both conditions, acute schizophrenics have a significantly greater RT with incongruent flanker conditions.\nThis indicates the nature of cognitive dysfunction for the latter may involve broadening of selective attention.\nStudies involving sufferers of [Parkinson's disease](https://bliptext.com/articles/parkinson-s-disease) found similar difficulties with suppressing incorrect response activation due to flanker interference, especially when under speed stress.\nModerate [exercise](https://bliptext.com/articles/physical-exercise), conversely, has been shown to improve performance on flanker tests, suggesting efficiency of cognitive control operates constructively with physical activity.\nCuriously, lowering [serotonin](https://bliptext.com/articles/serotonin) levels via [acute tryptophan depletion](https://bliptext.com/articles/acute-tryptophan-depletion) does not affect performance on a flanker task or corresponding EEG readings, but does alter cardiac response to incongruent stimuli, suggesting dissociation between cardiac and electro-cortical responses to errors and feedback when measuring cognitive flexibility.\n\n## Effect of sequential testing\nThe conflict effect of flanker interference have been well-documented to decrease with repeat testing, especially following incongruent/conflict conditions in what is known as the Gratton Effect.\nHowever the precise nature of these sequential dependencies is still subject to speculation; the effect may be stimulus-independent or stimulus-specific, and recent studies suggest the effect is not solely attributable to conflict adaptation but forms of associative [priming](https://bliptext.com/articles/priming-psychology).\nStill other research maintains the Gratton effect can be eliminated entirely if sequential biases are removed and that conflict adaptation failed to account for any performance results, suggesting instead support for a congruency [switch cost](https://bliptext.com/articles/task-switching-psychology) model.\nThe Gratton effect of conflict adaptation effect is also well documented in studies of [event-related brain potentials](https://bliptext.com/articles/event-related-potential) (ERPs), which typically show reduced activity for high-conflict trials following other high-conflict trials.\nNotably, after removing confounding alternative explanations of conflict adaptation, conflict adaptation is still observed in ERP indices.\nAn advantage of using ERPs is the ability to examine subtle differences in brain activity that do not appear in behavioral measures, such as response times or error rates.\n\n# Similar conflict tasks\nThere are three different types of conflict tasks that research has been largely focused on, one of these being the Eriksen Flanker Task.\nAll three of these tasks have mainly been viewed as identical in terms of the control processes that are involved.\nDue to this, inferences and predictions about one task have been made by theorists based on the published findings in a different task.\nAnother conflict task that receives significant focus is the [Stroop task](https://bliptext.com/articles/stroop-effect).\nIn this test, participants are told to name the color of a word as quickly as they can and as accurately as possible.\nThe trick is the word itself refers to a color.\nThe word can either be congruent, which would mean the word would match the font color, such as the word \"blue\" in blue font color, or it can be incongruent where the word would not match the font color like the word \"purple\" in yellow font color.\nJust as with the Eriksen Flanker Task, the response time and accuracy of congruent words is better than those of incongruent words.\nThe third task that is largely focused on is the [Simon](https://bliptext.com/articles/simon-effect) or spatial compatibility task.\nIn this task, the stimulus, either a word, letter, or symbol, is shown on the right or left side of the computer screen.\nThe participant is instructed to press the right or left button based on the content of the stimulus rather than its location.\nA congruent trial, for example, could be the word \"left\" shown on the left side of the screen, while an incongruent trial might be the word \"left\" on the right side of the screen.","current_revision":null,"created_by":"kACnuQmH5k9Nr5VNVEpVeg7XpvUmMctD","created_at":"2025-01-26T10:19:07.653Z","updated_at":"2025-01-26T10:19:07.653Z","search_vector":"'eriksen':1 'flanker':2 'task':3","search_content":" \n \n\n# \nIn [cognitive psychology](https://bliptext.com/articles/cognitive-psychology), the **Eriksen flanker task** is a set of response inhibition tests used to assess the ability to suppress responses that are inappropriate in a particular [context](https://bliptext.com/articles/context-language-use).\nThe target is flanked by non-target stimuli which correspond either to the same directional response as the target (congruent flankers), to the opposite response (incongruent flankers), or to neither (neutral flankers).\nThe task is named for American psychologists Barbara.\nA. Eriksen & [Charles W. Eriksen](https://bliptext.com/articles/charles-w-eriksen), who first published the task in 1974, and for the flanker stimuli that surround the target.\nIn the tests, a directional response (usually left or right) is assigned to a central target [stimulus](https://bliptext.com/articles/stimulus-psychology).\nVarious forms of the task are used to measure information processing and [selective attention](https://bliptext.com/articles/selective-attention).\n\n# Procedure and method\nIn an Eriksen Flanker Task there are three types of stimuli used:\nIn the original test described by Eriksen and Eriksen in 1974, letter stimuli were used.\n**S**ubjects were instructed to make directional responses to certain letters, for example a right response could be associated to the letters **H** and **K**, and a left response to **S** and **C**.\nEach stimulus consisted of a set of seven letters, with the target stimulus placed in the central position.\nExamples of congruent stimuli would be **HHHKHHH** and **CCCSCCC**, where both the target stimulus and the flankers correspond to the same directional response.\nExamples of incongruent stimuli could be **HHHSHHH** and **CCCHCCC **, where the central target letter and the flankers correspond to opposite directional responses.\nChoice reaction times (CRTs or RTs) were then recorded and compared between congruent and incongruent conditions.\nOther variants of the Eriksen Flanker Task have used numbers, color patches, or arrows as stimuli.\nAlso, although most Eriksen Flanker Tasks show the flankers on the left and right of the target, they can also be placed above or below the target, or in other spatial orientations.\nThese examples all use an arbitrary mapping between the stimulus and the response.\nAnother possibility is to use a natural mapping, with arrows as stimuli.\nFor example, Kopp et al. (1994) used left and right arrows, with flanker stimuli above and below the target.\nThe flankers could be arrows pointing in the same direction as the target (congruent) the opposite direction (incongruent) or squares (neutral).\nMore commonly, flankers have been arranged in a horizontal array, as with letter stimuli, so ** <<** an incongruent stimulus.\n# [Incongruent, congruent, and neutral stimuli represented by arrows. This is what a participant may see in a standard Eriksen Flanker Task | upload.wikimedia.org/wikipedia/commons/5/53/Congruent%2C///Incongruent%2C///and///Neutral///Flanker///stimuli.jpg]\n\n# Neurological basis\nWhen subjects participate in the Eriksen Flanker Task, the [anterior cingulate cortex](https://bliptext.com/articles/anterior-cingulate-cortex), or the ACC, is activated.\nThe ACC is a frontal brain structure responsible for a wide variety of [autonomic functions](https://bliptext.com/articles/autonomic-nervous-system).\nIt is observed to be more active in response to processing incongruent stimuli than congruent stimuli.\nIt is believed that the ACC may monitor the amount of conflict in an Eriksen Flanker trial.\nThen, that measured conflict is used to enhance the amount of control the participant has on the next trial.\nThus indicating that the more conflict presented on trial n, the more control expressed on trial n + 1.\nThis process leads to an interaction called the Gratton effect, which is the finding of a lower interference effect after an incongruent trial compared to the effect after a congruent trial.\nOn this first trial (trial n) the incongruent stimulus presented will lead to an increase in conflict detected by the ACC.\nOn trial n + 1, the increased conflict will lead to more control, causing the distracting, or flanker, stimuli to be more readily ignored.\n# [The Anterior Cingulate Cortex (ACC) is highlighted in yellow | upload.wikimedia.org/wikipedia/commons/1/10/MRI///anterior///cingulate.png]\n\n# Experimental findings\nThe flanker paradigm was originally introduced as a way of studying the cognitive processes involved in detection and recognition of targets in the presence of distracting information, or \"noise\".\nThe 1974 study found that CRT was significantly greater in incompatible than compatible conditions, a difference termed the flanker effect.\nEarlier work had used [visual search](https://bliptext.com/articles/visual-search), but because these tasks involve an active scan of the environment to identify the target stimulus, this experimental design made it difficult to separate the effects of distraction from the effects of the search process.\nIn the flanker paradigm, the position of the target is always known—there is no search process.\nNonetheless interference still occurs, so it can be studied independently of search mechanisms.\nEriksen and Schultz (1979) varied a number of features of the flanker tests, for example the size and contrast of the letters, or the use of forward or [backward masking](https://bliptext.com/articles/backward-masking).\nThey proposed a continuous flow model of perception in which information is processed in parallel for different stimulus elements, and accumulates over time until sufficient information is available to determine a response.\nMore recent work in this area has used neurophysiological measures such as [event-related potentials](https://bliptext.com/articles/event-related-potentials) or imaging techniques such as [fMRI](https://bliptext.com/articles/fmri).\n\n## Effects on performance\nA variety of factors have been shown to affect subject's performance on flanker tasks.\nAcute administration of [antihistamine](https://bliptext.com/articles/antihistamine) or [alcohol](https://bliptext.com/articles/alcohol-drug) severely impairs CRT in test measures, a deficit which Ramaekers et al. (1992) found to carry over to driving tests.\nThe study used an on-the-road driving tests, and several laboratory tests including the letter version of the Eriksen task to assess the effects of two antihistamines and alcohol on driving skills.\nBoth alcohol and the antihistamine [cetirizine](https://bliptext.com/articles/cetirizine) impaired performance in the test measures, and their effects were additive.\nThe non-sedating antihistamine [loratadine](https://bliptext.com/articles/loratadine) had no effect on any of the measures studied.\nThe arrow version of the flanker test has also been evaluated as a method of detecting impairment due to alcohol and drugs in drivers at the roadside, demonstrating the importance of selective attention skills to spatial abilities such as vehicle operation.\nVarious psychiatric and neurological conditions also affect performance on flanker tasks.\nWhile subjects with chronic schizophrenia performed similarly to control subjects on flanker tasks of both conditions, acute schizophrenics have a significantly greater RT with incongruent flanker conditions.\nThis indicates the nature of cognitive dysfunction for the latter may involve broadening of selective attention.\nStudies involving sufferers of [Parkinson's disease](https://bliptext.com/articles/parkinson-s-disease) found similar difficulties with suppressing incorrect response activation due to flanker interference, especially when under speed stress.\nModerate [exercise](https://bliptext.com/articles/physical-exercise), conversely, has been shown to improve performance on flanker tests, suggesting efficiency of cognitive control operates constructively with physical activity.\nCuriously, lowering [serotonin](https://bliptext.com/articles/serotonin) levels via [acute tryptophan depletion](https://bliptext.com/articles/acute-tryptophan-depletion) does not affect performance on a flanker task or corresponding EEG readings, but does alter cardiac response to incongruent stimuli, suggesting dissociation between cardiac and electro-cortical responses to errors and feedback when measuring cognitive flexibility.\n\n## Effect of sequential testing\nThe conflict effect of flanker interference have been well-documented to decrease with repeat testing, especially following incongruent/conflict conditions in what is known as the Gratton Effect.\nHowever the precise nature of these sequential dependencies is still subject to speculation; the effect may be stimulus-independent or stimulus-specific, and recent studies suggest the effect is not solely attributable to conflict adaptation but forms of associative [priming](https://bliptext.com/articles/priming-psychology).\nStill other research maintains the Gratton effect can be eliminated entirely if sequential biases are removed and that conflict adaptation failed to account for any performance results, suggesting instead support for a congruency [switch cost](https://bliptext.com/articles/task-switching-psychology) model.\nThe Gratton effect of conflict adaptation effect is also well documented in studies of [event-related brain potentials](https://bliptext.com/articles/event-related-potential) (ERPs), which typically show reduced activity for high-conflict trials following other high-conflict trials.\nNotably, after removing confounding alternative explanations of conflict adaptation, conflict adaptation is still observed in ERP indices.\nAn advantage of using ERPs is the ability to examine subtle differences in brain activity that do not appear in behavioral measures, such as response times or error rates.\n\n# Similar conflict tasks\nThere are three different types of conflict tasks that research has been largely focused on, one of these being the Eriksen Flanker Task.\nAll three of these tasks have mainly been viewed as identical in terms of the control processes that are involved.\nDue to this, inferences and predictions about one task have been made by theorists based on the published findings in a different task.\nAnother conflict task that receives significant focus is the [Stroop task](https://bliptext.com/articles/stroop-effect).\nIn this test, participants are told to name the color of a word as quickly as they can and as accurately as possible.\nThe trick is the word itself refers to a color.\nThe word can either be congruent, which would mean the word would match the font color, such as the word \"blue\" in blue font color, or it can be incongruent where the word would not match the font color like the word \"purple\" in yellow font color.\nJust as with the Eriksen Flanker Task, the response time and accuracy of congruent words is better than those of incongruent words.\nThe third task that is largely focused on is the [Simon](https://bliptext.com/articles/simon-effect) or spatial compatibility task.\nIn this task, the stimulus, either a word, letter, or symbol, is shown on the right or left side of the computer screen.\nThe participant is instructed to press the right or left button based on the content of the stimulus rather than its location.\nA congruent trial, for example, could be the word \"left\" shown on the left side of the screen, while an incongruent trial might be the word \"left\" on the right side of the screen.","revisionCount":0},"hasMore":false,"nextCursor":null}

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