The research presented here was supported by a SSHRC Standard Research Grant and a SSHRC Insight Grant to the 1st author and by a SSHRC Doctoral Fellowship and an Ontario Graduate Fellowship to the 2nd author. We wish to thank the members of the ERPLing lab for discussion of the data and for help with the testing of the participants.

All methods and procedures described here have been approved by the University of Ottawa Research Ethics Board.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/60479/60479fig1a.jpg" /> 
Figure 1: Stroop task sample stimuli. The color and noncolor terms as well as the background color used in the current experiment are shown. For Incongruent and Neutral stimuli, sample color-word stimuli are shown. In the experiment, any word could be in any of the six colors. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/60479/60479fig1alarge.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
1. Prepare the stimuli for the bilingual Stroop task
NOTE: The Stroop task can be programmed in many commercially available software packages designed for the presentation of behavioral experiments (see Table of Materials)
<ol>
	<li>Create the Congruent items in Language a (La) by programming six color terms written in capital letters in size 60 Times New Roman font, for which the written word and the font color match. For example, present the word GREEN in green font, and the word RED in red font.</li>
	<li>Create the Incongruent items in La by programming six color terms written in capital letters in size 60 Times New Roman font, for which the written word and the font color do not match. For example, present the word GREEN in red font, and the word RED in green font.</li>
	<li>Create the Neutral items in La by programming six noncolor and noncolor-associated terms, written in capital letters in size 60 Times New Roman font. Words are used instead of symbols in order to elicit baseline reading speeds for this reading-based task.
	<ol>
		<li>Present each word in each of the colors used in the previous two steps. For example, present the word BOOK in both green and red font.</li>
	</ol>
	</li>
	<li>Repeat the previous three steps to create items in Language b (Lb). Ensure that you do not use color terms that are cognates in the two languages (e.g., the word BLUE and BLEU in English and French, respectively.) 
	NOTE: In the current experiment, La was English, and the color terms used were RED, YELLOW, GREEN, BLACK, SILVER, and WHITE. Lb was French, and the color terms used were ROUGE, JAUNE, VERT, NOIR, ARGENT, and BLANC.</li>
</ol>
2. Create two single-language blocks
<ol>
	<li>Create an La block which includes 25 Congruent, 25 Incongruent, and 25 Neutral items, for a total of 75 items in the block. Include five Neutral practice items at the beginning of the block.</li>
	<li>Program the experiment to present all items in randomized intermixed trials as shown in Figure 2.</li>
</ol>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/60479/60479fig2a.jpg" /> 
Figure 2: Stroop task procedure. An incongruent trial is shown. Trials began with a 250 ms fixation cross and ended when the participant pressesed a response button or 4,000 ms elapsed. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/60479/60479fig2alarge.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<ol start="3">
	<li>Repeat the previous two steps with 25 Congruent, 25 Incongruent, and 25 Neutral items in Lb, for a total of 75 items in the block.</li>
	<li>Include a self-timed break between the two blocks, and a self-timed break before the presentation of the mixed-language block described in Part 3 below.</li>
</ol>
3. Create one mixed-language block
<ol>
	<li>Create a block which includes the 25 Congruent, 25 Incongruent, and 25 Neutral items in La, and the 25 Congruent, 25 Incongruent, and 25 Neutral items in Lb, for a total of 150 items in the block. Include five Neutral practice items at the beginning of the block.</li>
	<li>Program the experiment to present all items in randomized intermixed trials as shown in Figure 2.</li>
</ol>
4. Test participants
<ol>
	<li>Test participants in a sound-attenuated testing room or booth. Participants should be seated comfortably in front of a computer screen with a button box or keyboard in front of them.</li>
	<li>Explain to the participants that they will see words in different colors on the screen in front of them, and that their task is to press the button that matches the color of the text that they see. Emphasize that they should answer as quickly and accurately as possible, but that it is okay if they make a mistake. Allow time for participants to ask questions.</li>
	<li>Once participants are comfortable with the task, leave the testing room/booth and allow them to begin the experiment. The experiment will take approximately 8 min to complete.</li>
	<li>At the end of the experiment, thank the participants for their time and debrief them about the task and its purpose.</li>
</ol>

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The authors have nothing to disclose.

The experimental design presented here describes a twist on the traditional Stroop task. The main goal of this twist is to add a level of complexity to the task that may allow differences to emerge between groups that, due to their age, are being tested at their peak of performance. Essentially, to make the task more challenging in order to be able to distinguish between groups, we added a mixed-language block to the traditional Stroop task, which typically only collects data from trials in one language at a time. For th...

The Stroop task, named after its creator John Ridley Stroop, has enjoyed over 80 years of popularity in the literature1. This simple task has been used in hundreds of studies, with different variants created to examine diverse populations and research questions in fields such as psychology, linguistics, and neuroscience. In particular, it has allowed researchers to examine language processes such as the automaticity of written word reading2, as well as associated cognitive control processes. The latter are also termed &#34;executive control&#34;, and encompass a set of processes that include, but are not limited to, inhibition (i.e., interference suppression), attention, conflict monitoring and resolution, selection, and task switching. Looking specifically at bilinguals, the task is highly suitable for obtaining measures of language interference and control in both a bilingual&#39;s first language (L1) and second language (L2), as well as for testing the bilingual advantage hypothesis3, which is currently a topic of considerable debate.4
In the original task, the colors red, green, blue, brown, and purple were used in a series of three experiments. In the first experiment, participants read aloud a list of color words printed in incongruent colors (e.g., the word PURPLE printed in blue ink; correct answer &#34;purple&#34;) and the same list printed in black ink. In the second experiment, participants said aloud the color of the words in the list (e.g., the word PURPLE printed in blue ink; correct answer &#34;blue&#34;) and also named the same colors presented simply as colored squares. Finally, the third experiment examined whether practice of these tasks would affect the outcome, measured in all cases as the time required to read or to name the items in a given list.
The results revealed an interesting asymmetry between word-reading and color-naming: the difference between reading words in different colors and in black was a nonsignificant 2.3 seconds (or a 5.6% increase in the time required to read the color words), while the difference between naming the colors in which incongruent color words were written and naming the colors of squares was a 47.0 seconds, or a significant 74.3% increase in naming time for the words1. In other words, colors did not interfere with word reading, but reading strongly interfered with color naming. This increase in color naming time in the presence of a conflicting written word has come to be known as the Stroop effect, and while practice can reduce its magnitude, the interference cannot be altogether eliminated.
Different theories have been proposed to account for the Stroop effect, and in an extensive review of 50 years of Stroop literature, MacLeod5 describes two of the more predominant ones: 1) the relative speed of processing and 2) selective attention. In the former, words are read faster than colors are named, and this difference in relative processing time causes the Stroop effect. In the latter, the controlled, resource-intensive process of color naming occurs in parallel with the automatic process of reading; the direct competition between diverging word and color information is the source of interference and the Stroop effect2. The theory of selective attention is currently the more accepted view6,7,8,9.
Resolving the word-color competition is a cognitively demanding process that requires inhibiting distracting information while turning attention to the goal of the task. In order to correctly name the color, this interference from the automatically processed written word must be suppressed, while attention must be turned to the less practiced, and therefore controlled, task of color naming. Thus, the Stroop task becomes a measure of not only inhibition, but also of attention, and through various manipulations, it allows different levels of cognitive control to be examined10. Typically, a decreased magnitude of Stroop interference is considered indicative of better inhibition and attentional resource allocation. A full theoretical review of the Stroop task is beyond the scope of the current paper, but is available from previous works2,5. Although nonlinguistic versions of the Stroop task exist (e.g., numerical11, oculomotor12, spatial13), the current work is interested in linguistic cognitive control, and the remainder of the discussion will therefore be focused on the original linguistic version of the task.
The original Stroop task has undergone various modifications since 1935, and the task commonly used now includes a congruent condition where the color word is presented in the color it names (the word BLUE presented in blue ink; correct answer, &#34;blue&#34;) and a control condition that can be made up of colored shapes as in the original task, asterisks (***), a row of symbols such as X&#39;s, %&#39;s or #&#39;s, or high-frequency, noncolor-related words (e.g., DOG). These additions allow the Stroop task to examine facilitation effects. Facilitation effects are brought about by the convergence of information from the written word and the visual color in the congruent condition and thereby speed up naming times7 (although see MacLeod5 for reliability issues regarding facilitation effects). They can also be used to obtain baseline reading time or color naming time measures using the control items, in addition to Stroop interference effects. Facilitation and interference are defined as the difference in response time between the congruent and control, and as the difference between the incongruent and control trials, respectively, although the Stroop effect can sometimes be calculated as the difference between the congruent and incongruent trial, as in the original task6. In the task, the congruent, incongruent, and neutral conditions can be presented in individual blocks (all congruent, all incongruent, or all neutral trials) or in a single block made up of all three conditions, and in a variety of languages.
In the bilingual Stroop task, color terms in the bilingual&#39;s first language (L1) or second language (L2), or both, may be presented, and participants may be instructed to name the colors in either of their two languages. This type of task allows researchers to examine both within-language interference (by having the participant name L1 words in the L1 and L2 words in the L2) and between-language interference (naming L1 words in the L2, and vice versa), giving greater insight into how bilinguals process and manage their languages. For example, between-language interference can tell us about lexical representation and the strength of connections between languages in the mental lexicon, and this interference is typically smaller than within-language interference14.
A variety of language pairs have been used for the Stroop task&#39;s bilingual adaptation, including Chinese-English15,16, Japanese-English15,17,18, Spanish-English15,19,20, French-Arabic21, Arabic-Hebrew22, English-Greek14, English-German14, and Dutch-English7. As some have noted15, factors such as orthography in these languages can influence the magnitude of the within- and between-language interference. Still, despite differences in magnitude, the Stroop effect is always apparent.
It is important to note that many of the studies that incorporate two languages simultaneously20 require overt naming, which is susceptible to lexical access effects23. In tasks requiring a button press, the L1 and L2 are typically presented separately24, and only include three or four colors6,8. However, such a presentation may make the task too simple for young adults, whose cognitive control abilities are at their peak25, and result in all participants performing at ceiling. Thus, a single-language presentation with a small number of possible responses may not be sufficient to elicit any possible differences between groups of young adult bilinguals. Therefore, the current protocol seeks to increase the task challenge by increasing the number of color terms and mixing both the L1 and L2 items in a single block, thus not only examining reading automaticity, attention, and cognitive control processes, but also creating a task that is suitable for testing bilingual cognitive control in the young adult population.
In this bilingual task, stimuli were selected in English and French. An example of our stimuli in used is in Figure 1. However, any two languages can be used. For this reason, the protocol below will simply use Language A (La) and Language B (Lb) to describe stimuli in each language. For full details of the experimental protocol, please refer to our previous work26,27.

<table><tbody><tr><td>Button box</td><td>Cedrus</td><td></td><td>Button box for response; however, any response pad or the computer keyboard can be used to collect responses.</td></tr><tr><td>Desktop computer (Windows OS)</td><td>Dell</td><td></td><td>Computer system for delivering stimuli; however, any computer, including laptops, can be used.</td></tr><tr><td>Presentation</td><td>Neurobehavioural Systems</td><td></td><td>Software for presenting behavioural experiments; however, the experiment can be programmed using a variety of experimental software.</td></tr></tbody></table>

examining bilingual language control using the stroop task

The Stroop task in its many variations has been used in fields such as psychology, linguistics, and neuroscience to examine questions regarding the automaticity of reading, language processing, and cognitive control, among others. When looking at bilingual individuals, this task can be used to obtain measures of language interference and control in both a bilingual&#39;s first language (L1) and second language (L2), as well as for testing the bilingual advantage hypothesis. The Stroop task presents participants with color terms written in congruent colors (e.g., the word RED written in red font), incongruent colors (e.g., the word RED written in green font), in addition to noncolor terms for control (e.g., the word TREE presented in any color), and uses the reaction times from the different conditions to assess the degree of interference and facilitation. In the covert version of the Stroop bilingual task (i.e., participants respond by pressing a button rather than naming aloud), stimuli in the L1 and the L2 are typically presented in separate blocks. While this allows for a simple, yet effective assessment of processing and cognitive control in each language, it fails to capture any potential differences in processing and control within bilingual young adult groups. The present task combines single-language blocks with a novel mixed-language block to increase the level of difficulty of the task, thus making it suitable for testing cognitive control in young adults. Representative results showing differences between performance in the single-language vs. mixed-language blocks are presented, and the benefits of a mixed-language block are discussed.

One benefit of including both single-language blocks as well as a mixed-language blocks is that it is possible to confirm the expected results (facilitation and inhibition effects) in each of the participants&#39; languages. It will then be possible to interpret the findings from the mixed-language block. The results presented below are from a study investigating English-French Bilinguals. One of our main research questions focuses on how the age at which a second language is learned (age of acquisition, or AoA) may affe...

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Examining Bilingual Language Control Using the Stroop Task

This bilingual Stroop task uses Congruent, Incongruent, and Neutral stimuli presented in blocks in the first language (L1) only, the second language (L2) only, and a combination of L1 and L2. This task allows for an examination of language processing and cognitive control in both L1 and L2.

The Stroop task in its many variations has been used in fields such as psychology, linguistics, and neuroscience to examine questions regarding the ...

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Universidad San Sebastian

Research

JoVE Journal

Behavior

14.5K Views.  University of Ottawa. This bilingual Stroop task uses Congruent, Incongruent, and Neutral stimuli presented in blocks in the first language (L1) only, the second language (L2) only, and a combination of L1 and L2. This task allows for an examination of language processing and cognitive control in both L1 and L2.

Video: Examining Bilingual Language Control Using the Stroop Task

Training Synesthetic Letter-color Associations by Reading in Color

Synesthesia is a rare condition in which a stimulus from one modality automatically and consistently triggers unusual sensations in the same and/or other modalities. A relatively common and well-studied type is grapheme-color synesthesia, defined as the consistent experience of color when viewing, hearing and thinking about letters, words and numbers. We describe our method for investigating to what extent synesthetic associations between letters and colors can be learned by reading in color in nonsynesthetes. Reading in color is a special method for training associations in the sense that the associations are learned implicitly while the reader reads text as he or she normally would and it does not require explicit computer-directed training methods. In this protocol, participants are given specially prepared books to read in which four high-frequency letters are paired with four high-frequency colors. Participants receive unique sets of letter-color pairs based on their pre-existing preferences for colored letters. A modified Stroop task is administered before and after reading in order to test for learned letter-color associations and changes in brain activation. In addition to objective testing, a reading experience questionnaire is administered that is designed to probe for differences in subjective experience. A subset of questions may predict how well an individual learned the associations from reading in color. Importantly, we are not claiming that this method will cause each individual to develop grapheme-color synesthesia, only that it is possible for certain individuals to form letter-color associations by reading in color and these associations are similar in some aspects to those seen in developmental grapheme-color synesthetes. The method is quite flexible and can be used to investigate different aspects and outcomes of training synesthetic associations, including learning-induced changes in brain function and structure.

Reading in color is a new method for training letter-color associations that are typically found only in grapheme-color synesthetes. It involves an implicit form of training that has potential for long-term associative training methods&#160;because the training is a byproduct of reading and any text can be colored.

Synesthesia is a rare condition in which a stimulus from one modality automatically and consistently triggers unusual sensations in the same and/or other ...

A Dual Task Procedure Combined with Rapid Serial Visual Presentation to Test Attentional Blink for Nontargets

When viewers search for targets in a rapid serial visual presentation (RSVP) stream, if two targets are presented within about 500 msec of each other, the first target may be easy to spot but the second is likely to be missed. This phenomenon of attentional blink (AB) has been widely studied to probe the temporal capacity of attention for detecting visual targets. However, with the typical procedure of AB experiments, it is not possible to examine how the processing of non-target items in RSVP may be affected by attention. This paper describes a novel dual task procedure combined with RSVP to test effects of AB for nontargets at varied stimulus onset asynchronies (SOAs). In an exemplar experiment, a target category was first displayed, followed by a sequence of 8 nouns. If one of the nouns belonged to the target category, participants would respond &#8216;yes&#8217; at the end of the sequence, otherwise participants would respond &#8216;no&#8217;. Two 2-alternative forced choice memory tasks followed the response to determine if participants remembered the words immediately before or after the target, as well as a random word from another part of the sequence. In a second exemplar experiment, the same design was used, except that 1) the memory task was counterbalanced into two groups with SOAs of either 120 or 240 msec and 2) three memory tasks followed the sequence and tested remembrance for nontarget nouns in the sequence that could be anywhere from 3 items prior the target noun position to 3 items following the target noun position. Representative results from a previously published study demonstrate that our procedure can be used to examine divergent effects of attention that not only enhance targets but also suppress nontargets. Here we show results from a representative participant that replicated the previous finding.&#160;

This paper describes a novel dual task procedure combined with Rapid Serial Visual Presentation to look at attentional blink at varied stimulus onset asynchronies. This experimental procedure differed from others in that it tested attentional blink for nontargets.

When viewers search for targets in a rapid serial visual presentation (RSVP) stream, if two targets are presented within about 500 msec of each other, the ...

The Emotional Stroop Task: Assessing Cognitive Performance under Exposure to Emotional Content

The emotional Stroop effect (ESE) is the result of longer naming latencies to ink colors of emotion words than to ink colors of neutral words. The difference shows that people are affected by the emotional content conveyed by the carrier words even though they are irrelevant to the color-naming task at hand. The ESE has been widely deployed with patient populations, as well as with non-selected populations, because the emotion words can be selected to match the tested pathology. The ESE is a powerful tool, yet it is vulnerable to various threats to its validity. This report refers to potential sources of confounding and includes a modal experiment that provides the means to control for them. The most prevalent threat to the validity of existing ESE studies is sustained effects and habituation wrought about by repeated exposure to emotion stimuli. Consequently, the order of exposure to emotion and neutral stimuli is of utmost importance. We show that in the standard design, only one specific order produces the ESE.

The emotional Stroop effect (ESE) is the result of longer naming latencies to ink colors of emotion words than those of neutral words. This report refers to potential sources of confounding and includes a modal experiment that provides the means to control for them.

The emotional Stroop effect (ESE) is the result of longer naming latencies to ink colors of emotion words than to ink colors of neutral words. The ...

Comparing the Frequency Effect Between the Lexical Decision and Naming Tasks in Chinese

In psycholinguistic research, the frequency effect can be one of the indicators for eligible experimental tasks that examine the nature of lexical access. Usually, only one of those tasks is chosen to examine lexical access in a study. Using two exemplar experiments, this paper introduces an approach to include both the lexical decision task and the naming task in a study. In the first experiment, the stimuli were Chinese characters with frequency and regularity manipulated. In the second experiment, the stimuli were switched to Chinese two-character words, in which the word frequency and the regularity of the leading character were manipulated. The logic of these two exemplar experiments was to explore some important issues such as the role of phonology on recognition by comparing the frequency effect between both the tasks. The results revealed different patterns of lexical access from those reported in the alphabetic systems. The results of Experiment 1 manifested a larger frequency effect in the naming task as compared to the LDT, when the stimuli were Chinese characters. And it is noteworthy that, in Experiment 1, when the stimuli were regular Chinese characters, the frequency effect observed in the naming task was roughly equivalent to that in the LDT. However, a smaller frequency effect was shown in the naming task as compared to the LDT, when the stimuli were switched to Chinese two-character words in Experiment 2. Taking advantage of the respective demands and characteristics in both tasks, researchers can obtain a more complete and precise picture of character/word recognition.

Researchers adopt both the lexical decision task and the naming task to investigate some important topics such as character/word recognition by comparing the frequency effect between these two tasks. This article introduces this approach through two exemplar experiments and elaborates on the underlying logic.

In psycholinguistic research, the frequency effect can be one of the indicators for eligible experimental tasks that examine the nature of lexical access. ...

Transcranial Direct Current Stimulation (tDCS) of Wernicke's and Broca's Areas in Studies of Language Learning and Word Acquisition

Language is a highly important yet poorly understood function of the human brain. While studies of brain activation patterns during language comprehension are abundant, what is often critically missing is causal evidence of brain areas&#39; involvement in a particular linguistic function, not least due to the unique human nature of this ability and a shortage of neurophysiological tools to study causal relationships in the human brain noninvasively. Recent years have seen a rapid rise in the use of transcranial direct current stimulation (tDCS) of the human brain, an easy, inexpensive and safe noninvasive technique that can modulate the state of the stimulated brain area (putatively by shifting excitation/inhibition thresholds), enabling a study of its particular contribution to specific functions. While mostly focusing on motor control, the use of tDCS is becoming more widespread in both basic and clinical research on higher cognitive functions, language included, but the procedures for its application remain variable. Here, we describe the use of tDCS in a psycholinguistic word-learning experiment. We present the techniques and procedures for application of cathodal and anodal stimulation of core language areas of Broca and Wernicke in the left hemisphere of the human brain, describe the procedures of creating balanced sets of psycholinguistic stimuli, a controlled yet naturalistic learning regime, and a comprehensive set of techniques to assess the learning outcomes and tDCS effects. As an example of tDCS application, we show that cathodal stimulation of Wernicke&#39;s area prior to a learning session can impact word learning efficiency. This impact is both present immediately after learning and, importantly, preserved over longer time after the physical effects of stimulation wear off, suggesting that tDCS can have long-term influence on linguistic storage and representations in the human brain.

Transcranial Direct Current Stimulation tDCS of Wernicke's and Broca's Areas in Studies of Language Learning and Word Acquisition

Here, we describe a protocol for using transcranial direct current stimulation for psycho- and neurolinguistic experiments aimed at studying, in a naturalistic yet fully controlled way, the role of cortical areas of the human brain in word learning, and a comprehensive set of behavioral procedures for assessing the outcomes.

Language is a highly important yet poorly understood function of the human brain. While studies of brain activation patterns during language comprehension ...

Examining Online Syntactic Processing of Spoken Complex Sentences in Chinese Using Dual-Modal Interference Tasks

Working memory (WM) plays a central role in the comprehension of complex sentences. Its function in the processing of spoken complex sentences is especially evident because spoken complex sentence processing is memory-intensive. The dual-modal interference paradigm has been used to examine how the WM system is involved in complex syntactic processing. This article presents two exemplar experiments involving auditory processing with either intra- or extrasentential interferences. In the first experiment, auditory stimuli [spoken-Chinese relative clause (RC) sentences with two syntactic types: subject-gapped (SRC) vs. object-gapped (ORC)] are interfered with via a visually presented lexical decision task within a sentence and manipulated using three different interference timepoints. In the second experiment, the same auditory stimuli, presented via an auditory window moving technique, are interfered with via a visually presented digital recall task beyond the sentence and manipulated using three digital memory loads. By assessing how the primary task of comprehending the RC sentences is affected by the secondary task, we can tackle the controversial issue concerning Chinese RC processing asymmetry. Our results reveal different patterns of RC processing compared to those reported in previous studies. Experiment 1 manifests no clear RC processing advantages in either SRC or ORC; however, a preference for ORC is observed at the ends of sentences, and a preference for SRC is found at the main verb site. Likewise, Experiment 2 presents a dynamic pattern. Under a no-digit load, SRCs show processing advantages in the RC marker region. However, under higher-digit-load interference, ORCs show processing advantages in the same region. These results lead to the conjecture that no obvious or intrinsic processing asymmetry exists in the processing of Chinese RCs. Using the approach of assessing specific interference during syntactic processing, these experiments demonstrate future research applications that explore the processing metrics of spoken sentences involving working memory.

Here, we present a protocol employing dual-modal interference tasks to examine online processing of spoken-Chinese relative clause sentences. Two exemplar experiments involving auditory processing with intra- and extrasentential interferences are described. The paradigm provides a methodology for addressing the nature of working memory and its effects on sentence processing.

Working memory (WM) plays a central role in the comprehension of complex sentences. Its function in the processing of spoken complex sentences is ...

Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment

Older adults are slower at recognizing visual objects than younger adults. The same is true for recognizing that a letter string is a real word. People with Alzheimer&#39;s disease (AD) or Mild Cognitive Impairment (MCI) demonstrate even longer responses in written word recognition than elderly controls. Despite the general tendency towards slower recognition in aging and neurocognitive disorders, certain characteristics of words influence word recognition speed regardless of age or neuropathology (e.g., a word&#8217;s frequency of use). We present here a protocol for examining the influence of lexical characteristics on word recognition response times in a simple lexical decision experiment administered to younger and older adults and people with MCI or AD. In this experiment, participants are asked to decide as quickly and accurately as possible whether a given letter string is an actual word or not. We also describe mixed-effects models and principal components analysis that can be used to detect the influence of different types of lexical variables or individual characteristics of participants on word recognition speed.

This article describes how to implement a simple lexical decision experiment to assess written word recognition in neurologically healthy participants and in individuals with dementia and cognitive decline. We also provide a detailed description of reaction time analysis using principal components analysis (PCA) and mixed-effects modeling.

Older adults are slower at recognizing visual objects than younger adults. The same is true for recognizing that a letter string is a real word. People ...

Evaluation of the Cognitive Performance of Hypertensive Patients with Silent Cerebrovascular Lesions

Evidence accumulated from the last decade has proven that silent cerebrovascular lesions (SCLs) and their underlying pathogenic processes contribute to cognitive decline in the elderly. However, the distinct effects of each type of the lesions on cognitive performance remain unclear. Moreover, research data from Chinese elderly with SCLs is scarce. In this study, 398 otherwise healthy hypertensive elderly subjects (median age 72 years) were included and assessed. All participates were required to complete a battery of structured neuropsychological assessment, including forward and backward digit span tests, symbol digit modalities test, Stroop test, verbal fluency test and Montreal Cognitive Assessment. These tests were used to assess attention, executive function, information processing speed, language, memory and visuospatial function. A multi-sequence 3T MRI scanning was arranged within one month of the neuropsychological assessment to evaluate the burden of SCLs. SCLs were rated visually. Cerebral microbleeds (CMBs) and silent lacunes (SLs) were identified as strictly lobar CMBs and SLs or deep CMBs and SLs according to their locations, respectively. Similarly, white matter hyperintensities (WMHs) were separated into periventricular WMHs (PVHs) and deep WMHs (DWMHs). A series of linear regression models were used to assess the correlation between each type of SCLs and individual cognitive function domain. The results showed that CMBs tend to impair language-related cognition. Deep SLs affect executive function, but this association disappeared after controlling for other types of SCLs. PVHs, rather than DWMHs, are associated with cognitive decline, especially in executive function and processing speed. It is concluded that different aspects of SCLs have differential impact on cognitive performance in hypertensive elderly Chinese.

Here, we present a protocol to assess whether various types of silent cerebrovascular lesions are differentially associated with deficits in certain cognitive domains in a cohort of 398 hypertensive elderly Chinese, using a combination of neuropsychological tests and multi-sequence 3T MRI scanning.

Evidence accumulated from the last decade has proven that silent cerebrovascular lesions (SCLs) and their underlying pathogenic processes contribute to ...

Dual-Task Stroop Paradigm for Detecting Cognitive Deficits in High-Functioning Stroke Patients

General clinical cognitive assessment scales are not sensitive enough to cognitive impairment in high-functioning stroke patients. The dual-task assessment has advantages for identifying cognitive deficits in high-functioning stroke patients and has been gradually applied in clinical assessment and cognitive training. Moreover, the Stroop paradigm has higher sensitivity and specificity for attentional assessment than conventional clinical cognitive assessment scales. Therefore, this study presents the dual-task assessment based on the Stroop paradigm to identify cognitive deficits in high-functioning stroke patients. This study demonstrates a single- and dual-task evaluation based on the Stroop paradigm and confirms its feasibility through case experiments and synchronized functional near-infrared spectroscopy evaluation. The Stroop reaction time and correct rate are used as the main indicators to evaluate the cognitive level of the subjects. This study protocol aims to provide new ideas to figure out the ceiling effect in general clinical assessment failure for high-functioning stroke patients.

Clinical assessment scales are notsensitive enough to cognitive dysfunction in high-functioning stroke patients. The dual-task paradigm presents advantages and potential in the assessment and cognitive training of cognitive dysfunction. The study here proposes a dual-task Stroop paradigm to identify cognitive dysfunction in high-functioning stroke patients.

General clinical cognitive assessment scales are not sensitive enough to cognitive impairment in high-functioning stroke patients. The dual-task ...

Neuroscience

Executive Function in Autism Spectrum Disorder

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel&#8212;University of Southern California
Attention, working-memory, planning, impulse control, inhibition, and mental flexibility are important components of human cognition that are often referred to as executive functions. Autism spectrum disorder is a developmental disorder that is characterized by impairments in social interaction, communication, and repetitive behaviors. It is a disorder that lasts a lifetime, and is thought to affect 0.6% of the population. The symptoms of autism suggest a deficit in executive function, which may be assessed by specialized neuropsychological tests. By employing several tests that each emphasize different aspects of executive function, we can gain a more complete picture of the cognitive profile of the disorder. 
One such task, known as the Wisconsin Card Sorting Test (WCST), is a cognitively complex task used widely in research and clinical studies as a highly sensitive measure of deficits in executive function. It tests a person's ability to shift attention and tests their flexibility with changing rules and reinforcement.1 In the WCST, a participant is presented with four stimulus cards, incorporating three stimulus parameters: color, shape, and number. The participant is asked to sort response cards according to different principles, changing their sorting criteria based on feedback from the experimenter. Participants try out different rules until they find the correct method for sorting the cards. Patients with executive dysfunction tend to get stuck in the card sorting task, unable to change their sorting strategy. This persistence with an incorrect strategy is called perseveration. 
A second task, The Tower of London (ToL) is a test dependent on complex planning, re-evaluation, and updating of planned moves. Individuals with autism have been reported to be impaired on tasks involving planning.2 In the ToL task, individuals must move disks from a prearranged sequence on three pegs to match a goal state in as few moves as possible, following specific rules. 
A third task, known as the Stroop test, targets cognitive inhibition. In this task participants are shown a name of a color, written in a different color, and are asked to identify the color the word is written in. For example, in an incongruent condition, the word blue would be written in green. Individuals with inhibition difficulty should not perform as well as typically developing individuals on this task involving inhibition of the written word.
In this video, we show how to administer the WCST, ToL, and Stroop task to compare flexibility, planning, and inhibition in children with autism spectrum disorder and typically developing counterparts, and explore how each of these groups performs on these different aspects of executive function.

Behavioral Tests to Assess Executive Functions in Children with ASD

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel&#8212;University of Southern California
Attention, working-memory, planning, impulse control, ...