The authors have no acknowledgements.

The protocol follows the guidelines of Tel-Aviv University Helsinki human research ethics committee.
1. Word Selection and Matching 
<ol>
	<li>Create lists of words for each word category of interest. For example, make lists of generally emotional words (e.g., HATE, POX), concern relevance words (e.g., RAPE, VICTIM), and neutral words that are preferably orthographic neighbors21 of the emotional/concern relevant words (e.g., GATE, BOX). Create lists with as many words as possible as not all of these words will be used; a smaller subset of matched words will later be selected.&#160;
	<ol>
		<li>When deemed necessary, verify the valence/emotionality/arousal of the words by a questionnaire rating the words on a rating scale (e.g., from 1 to 7). Attempt to select words that are at the extreme end of the scale. If comparing emotional words with positive words, attempt to include words that are matched on (absolute) emotionality and arousal scores.</li>
	</ol>
	</li>
	<li>Write for each word on the lists, its length in characters as well as its estimated frequency in the appropriate language (for English words, use log hyperspace analogue to language (HAL) frequency22) in order to match the word lists on lexical factors. 
	NOTE: This is important as these variables can also affect color naming latency (e.g., 21, 23). Arguably, the most important lexical attributes to control are word frequency, length, and if possible orthographic neighborhood (which naturally intersect with length).
	<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
		<tbody>
			<tr>
				<td></td>
				<td>Emotional&#160;</td>
				<td></td>
				<td></td>
				<td>Neutral</td>
				<td></td>
			</tr>
			<tr>
				<td>Word</td>
				<td>Length</td>
				<td>Frequency</td>
				<td>Word</td>
				<td>Length</td>
				<td>Frequency</td>
			</tr>
			<tr>
				<td>hate</td>
				<td>4</td>
				<td>10.7</td>
				<td>gate</td>
				<td>4</td>
				<td>9.7</td>
			</tr>
			<tr>
				<td>dead</td>
				<td>4</td>
				<td>11.2</td>
				<td>dear</td>
				<td>4</td>
				<td>10.29</td>
			</tr>
			<tr>
				<td>poor</td>
				<td>4</td>
				<td>10.9</td>
				<td>pool</td>
				<td>4</td>
				<td>9.7</td>
			</tr>
			<tr>
				<td>snake</td>
				<td>5</td>
				<td>8.6</td>
				<td>shake</td>
				<td>5</td>
				<td>8.6</td>
			</tr>
			<tr>
				<td>gloom</td>
				<td>5</td>
				<td>8.1</td>
				<td>bloom</td>
				<td>5</td>
				<td>8.2</td>
			</tr>
			<tr>
				<td>bomb</td>
				<td>4</td>
				<td>9.64</td>
				<td>comb</td>
				<td>4</td>
				<td>7.39</td>
			</tr>
			<tr>
				<td>pox</td>
				<td>3</td>
				<td>7.1</td>
				<td>box</td>
				<td>3</td>
				<td>12.1</td>
			</tr>
			<tr>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td>Average</td>
				<td>4.1</td>
				<td>9.4</td>
				<td>Average</td>
				<td>4.1</td>
				<td>9.4</td>
			</tr>
		</tbody>
	</table>
	Table1: Example of a List of Words Matched on Length, Orthographic Neighborhood, and Average Frequency.</li>
	<li>Select words by adding pairs each time that match in length and frequency, and that are orthographic neighbors of one another (for example replace one of the emotional word letters with another to form a neutral orthographic neighbor, (see Table 1).
	<ol>
		<li>If a complete match is not possible, balance the bias of frequency in the subsequent pairs of words by adding a pair of words with a small gap in frequency in the opposite direction of the gap formed by the previous pair of words. Ensure that the final lists of matched words contain 20 - 50 words in each word category in order to have a minimum of 20 trials in a block to collect sufficient data and avoid repetition of words and hence habituation3. 
		NOTE: If many words are difficult to obtain, it is possible to introduce some repetition of words. However try to keep repetitions to a minimum as it may dilute the ESE due to habituation3.</li>
	</ol>
	</li>
	<li>Check that the final list is matched as much as possible on all lexical variables (e.g., word frequency, word length). Perform a statistical validation (student&#39;s t-test) to confirm that the final lists do not differ significantly from each other on frequency.</li>
</ol>
2. Preparation of Experimental Design
<ol>
	<li>Select the design: Blocked (the stimuli are presented in separate blocks of trials defined by word valence) or mixed (the stimuli are presented in one block in which emotion and neutral words are intermixed in the same list).
	<ol>
		<li>Choose a blocked design if seeking to test global effects at the level of the word category. 
		NOTE: Effect sizes are usually higher in a blocked design than in a mixed presentation4, 5. Therefore, blocked design is often the favored method of presentation.</li>
		<li>Choose a mixed design if seeking to decompose the ESE at the individual word level and for &#34;fast&#34; and &#34;slow&#34; effects, as a negative item can affect not only its own naming (the ESE) but also that of the immediately following item. Consequently, the former is dubbed &#39;fast effect,&#39; the latter &#39;slow effect&#39;24, 25.</li>
	</ol>
	</li>
	<li>In a blocked experimental design, select a fixed or counterbalanced/randomized order of blocks.
	<ol>
		<li>For a counterbalanced order present the two possible order of blocks to different groups of participants: 
		Group A: Neutral Block - Emotional Block 
		Group B: Emotional Block - Neutral Block 
		NOTE: In this balanced design, an ESE is expected to emerge only in the group performing in the first order due to sustained effects in the group performing in the second order (see Figure 4)3. We therefore suggest using a fixed presentation of blocks.</li>
		<li>For a fixed order of blocks present first the neutral block then the emotional block, and if desired present an additional new neutral block flowing the emotional block in order to examine sustained effects: Neutral Block 1 - Emotional Block - Neutral Block 2. 
		NOTE: In this setup, two effects can be observed. The first is the canonical ESE, calculated as the difference in performance between the emotional block and the first neutral block. A second is a sustained effect, obtained by subtracting the mean latency of the second neutral block from that of the first neutral block. A positive difference indicates the presence of sustained effects brought about by the emotional block.
		<ol>
			<li>In order to rule out confounding through training or fatigue, advisably perform an auxiliary experiment with several blocks of neutral items only. 
			NOTE: With three blocks of 40 neutral words, no residual fatigue is expected (see Figure 3)3. If there are more than 40 words per block, or more experimental blocks, it may be necessary to control for effects of fatigue by counterbalancing block order (but check for order-of-blocks effects in the statistical analysis).</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
3. Experimental Programing and Randomization
<ol>
	<li>Choose a computer software or programing language to serve as a vehicle to present the stimuli and measure the participant&#39;s responses.
	<ol>
		<li>Optionally, use the commercially available DirectRT software which is relatively easy to deploy and reliable. See Supplemental Code File for a DirectRT executable excel file as an example for a typical programed ESE experiment. Some additional software packages are SuperLab and E-prime, which are also suitable alternatives for governing the experiment.</li>
	</ol>
	</li>
	<li>Select the method of responding: manual or oral. Both types of responding are appropriate.
	<ol>
		<li>For keyboard activated responding, use a longer training session in order for the participant to learn the mapping of keys onto the ink colors (of about 20 - 40 trials).</li>
		<li>For vocal responding use a shorter training session (of 4 - 8 trials). Set the reaction time to be measured from the outset of the stimulus to the first phoneme said. 
		NOTE: Vocal responses pose difficulties at the stage of deciphering the responses (one must listen to the recordings and classify errors). However, a new algorithm that mechanically classifies the vocal recordings can render actual human classification gratuitous26. An advantage of oral responses is that the resulting auditory files can be further analyzed (via other dedicated programs) for vocal parameters associated with emotion3.</li>
	</ol>
	</li>
	<li>Choose the ink-colors to be assigned to the words (e.g., the colors blue, green, red, and purple). Use easily discriminable colors against a well contrasted background (e.g., white or grey). If key-press responding is used, use no more than 4 colors, so that the mapping of colors to the keys is easily mastered. 
	NOTE: If vocal responding is used, it is possible to use many more colors. Recall though that with a computer algorithm to classify the data, voice-identification errors increase with the number of colors (= responses).</li>
	<li>Use an easily legible font, and size for the words.</li>
	<li>Since the preferred approach is to use no repetition of words, assign to each word a single color randomly by the computer program for every participant.</li>
	<li>Present each word singly around the middle of the computer screen. Optionally, introduce a small amount of spatial uncertainty, so that each word is presented in a random different position approximately 50 pixels around the center (e.g., see Supplemental Code File). This is done in order to discourage participants focusing on a small section of the word (thus circumventing reading).</li>
	<li>Prepare a short training block to familiarize the participant with the task and the stimuli. For vocal responding, a few trials using the word &#39;example&#39; in each of the experimental colors may suffice (with computerized identification of data, a whole session is needed to train the voice-identification algorithm); for key-press responding, as many as 20 - 40 trials may be necessary to master the mapping of the colors.</li>
	<li>Following training, present the experimental blocks (e.g., three blocks of neutral-emotional and neutral words). Introduce short breaks between successive blocks of trials (of say, 30-60 seconds each). Do not allow the next block to begin before the designated interval for the break has elapsed as participants tend to rush through the experiment in order to finish it quickly.</li>
	<li>Prepare the task instructions. At the start of each block, present the following instruction &#39;Respond to the ink color of the word as quickly and accurately as possible.&#39; Avoid mentioning word reading, or that the word should be ignored as this request may artificially augment reading the words (see ironic process theory, e.g., 27).</li>
	<li>Specify the inter-trial or inter-stimulus interval (ISI) between experimental trials of a stimulus and the successive stimulus. Typically use an ISI of 500 msec (in blocked presentation). 
	NOTE: Short ISI may promote shorter responses than longer ISI and carry over-effects with emotion items have been reported for ISI up to 1,000 msec24.</li>
	<li>Optional: Add an anxiety questionnaire at the end of the experiment or in a separate session. This provides for a baseline measure of the participant&#39;s anxiety, such as the state-trait anxiety inventory (STAI)28.</li>
</ol>
4. Subject Selection and Preparation
<ol>
	<li>Once programing is completed, recruit participants preferably from the same age-group and background. Participants can enroll for course credit, for pay, or on a voluntary basis.</li>
	<li>Make sure participants are native speakers of the language used in the study, and do not have any attention deficits or color blindness.</li>
	<li>Guide the participant to a quiet room in front of a computer. Explain the task instructions and ask the participant to read additional instructions written on the computer screen.</li>
</ol>
5. Data and Statistical Analysis
<ol>
	<li>As a rule, perform reaction time analyses with respect to correct responses only. Also, exclude extreme responses.
	<ol>
		<li>Typically, exclude responses faster or smaller than 2.5 SD around the mean. Nevertheless, be careful not to discard more than 5% of the data. Error rates are typically small, but it is still advisable to compare them across conditions and rule out a speed-accuracy tradeoff.</li>
	</ol>
	</li>
	<li>With a fixed presentation order, perform planned comparisons (or a student&#39;s t-test, if only two blocks are administered) with a designated statistical software such as SPSS or STATISTICA (here instructions are given for STATISTICA). For testing of the ESE, compare the emotion block with the first neutral block. For sustained effects compare the second neutral block (which followed the emotional block) with the first neutral block.
	<ol>
		<li>Perform planned comparisons by choosing -Statistics-&#62;Advanced Linear/Non-Linear Models-&#62;General Linear Models-&#62;More results -&#62; Planed comps.</li>
	</ol>
	</li>
	<li>When the order of blocks is counterbalanced across participants, perform an ANOVA with Block Valence as a within-subject factor and Order of Blocks as a between-subject factor.
	<ol>
		<li>Perform ANOVA by choosing -Statistics-&#62;Advanced Linear/Non-Linear Models-&#62;General Linear Models.</li>
	</ol>
	</li>
</ol>

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J., Stough, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Test-retest+reliability+of+the+emotional+stroop+task:+Examining+the+paradox+of+measurement+change.">Test-retest reliability of the emotional stroop task: Examining the paradox of measurement change.</a> J.Psychol. 136 (5), 514-520 (2002).</li><li>Macleod, C., Mathews, A., Tata, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Attentional+Bias+in+Emotional+Disorders.">Attentional Bias in Emotional Disorders.</a> J.Abnorm.Psychol. 95 (1), 15-20 (1986).</li></ol>

The authors have nothing to disclose.

The ESE comprises a very simple task: The participant names the ink color of singly presented words. This simple task yields results of both pragmatic and theoretical consequence. The ESE documents the fact that people are sensitive to the emotional valence entailed in stimuli although this feature is completely irrelevant to the task at hand.
The ESE has evolved into an immensely popular method for probing emotion and anxiety with both patient and non-patient populations1, 74<...

Modern life is replete with emotion and stress. Who has avoided the emergency room or (witnessing) a traffic accident? In order to perform efficiently under such stressful situations, it is important to preserve one&#39;s composure by focusing on the relevant stimuli. However, research has shown that the emotional valence of the stimulus can affect attention, in particular modulate the speed of processing. In the laboratory, one of the most popular paradigms to study the effect of negative stimuli on performance is the emotional Stroop task. The typical finding is that it takes people longer to name the ink color of emotion words than that of neutral words, the Emotional Stroop Effect (ESE). There are several accounts that attempt to explain the observed slowdown attributing attention3, freezing2, or mood3, however it is still a matter of current debate.
The experimental setup of the emotional Stroop task is well known. Words in color are presented singly for view and the participant&#39;s task is to name the ink color of each word as quickly and accurately as possible. The words come from two categories of different valence. The first category includes negative words (e.g., DEATH) or words related to a specific psychopathology (e.g., GERMS with obsessive-compulsive patients or BATTLE with post-traumatic stress disorder patients). The second category includes neutral words (e.g., CHAIR). The ESE is the difference in color-naming latency between the emotional and the neutral words. The stimuli can be presented in a single block with emotion and neutral words intermixed in a random fashion or in two separate blocks defined by word category. The slowdown with emotion words is usually more pronounced when the ESE is derived in the blocked design4, 5. Therefore, the block design has become the method of choice for researches of the ESE and it is the method applied in this protocol too (see Figure 1 for an illustration of the emotional Stroop experimental setup).
<img alt="Figure 1" src="/files/ftp_upload/53720/53720fig1.jpg" /> 
Figure 1: The Experimental Array in the Emotional Stroop Task: The participant&#39;s task is to name color in which the word appears. <a href="https://www.jove.com/files/ftp_upload/53720/53720fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
It is important to distinguish the ESE from its older namesake, the classic Stroop effect (SE)6. In the classic Stroop task, color words such as RED or GREEN are presented in various ink colors and the participant&#39;s task is to name the ink color of the words. Despite the shared task &#8212; to identify the ink color of words&#160;&#8212; the SE and the ESE differ. Because the words are color words, the stimuli in the classic Stroop task divide into congruent (the word naming its ink color) and incongruent (word and color conflict) categories. The SE is defined as the difference in color naming performance between congruent and incongruent stimuli. Because the quality of congruity does not apply to stimuli in the ESE&#160;&#8212; the word CANCER in blue is neither more nor less congruent than the word LECTURE in brown&#160;&#8212; the SE is not defined in the environment of the ESE. The ESE documents the effect of the emotional valence of the stimuli on performance.
The ESE, just like the SE, has generated voluminous research. In fact, the ESE rivals its namesake in sheer output of experimental studies with both patient and non-patient populations (for a review, see1, 7). The task has been employed with a gamut of pathologies from generalized anxiety (e.g., 8, 9) to trait anxiety (e.g., 10, 11) to obsessive-compulsive disorders (e.g., 12, 13) to depression9, 14 to social phobia15, 16 to post-traumatic stress disorders (e.g., 17, 18). The ESE has also been studied with unselected populations (e.g., 2, 3, 19, 20), although the effects in heathy participants are not always observed and are often less pronounced. At least a portion of ESE&#39;s popularity is attributable to its objective nature as it is not based on self-report and is not intrusive. Furthermore, the emotion words can be selected to tap the specific pathology or current concern of the patient.
Below, we portray the steps required to design and perform an emotional Stroop experiment. Our purpose in this report is to describe in detail an ESE experiment with needed controls. The most important feature of this design is the control it provides against various threats to validity. The main threat treated in this design is that of habituation. Adopting these procedures renders the ESE a valid and reliable means of assessing attention under emotion.

<table>
	<tbody>
		<tr>
			<td>DirectRT software</td>
			<td>Empirisoft</td>
			<td>http://www.empirisoft.com/directrt.aspx</td>
			<td>Software allows easy programing of a custom experiment in a spreadsheet application (e.g., Excel)</td>
		</tr>
		<tr>
			<td>Personal computer</td>
			<td>Any</td>
			<td><a href="https://www.office.com/">https://www.office.com/</a></td>
			<td>&#160;At least 256mb of memory, a graphics card with at least 16mb of video memory and a processor speed of at least 500mhz.&#160;</td>
		</tr>
		<tr>
			<td>A spreadsheet application (e.g., Excel)</td>
			<td>Microsoft</td>
			<td>Any version</td>
			<td>A spreadsheet application capable of editing CSV files</td>
		</tr>
		<tr>
			<td>SPSS/STATISTICA software</td>
			<td>IBM/Statsoft</td>
			<td>http://www-01.ibm.com/software/analytics/spss/&#160; http://www.statsoft.com/</td>
			<td>Statistical software</td>
		</tr>
	</tbody>
</table>

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.

When blocks follow the neutral-emotion-neutral sequence (e.g., 3), a large ESE of 34 msec is observed via slower responses in the emotion block (mean of 791 msec) than in the first neutral block (mean of 757 msec; see Figure 2). The same group of participants was also fairly sluggish to name the ink color in the second set of (other) neutral words (mean of 778 msec). The 21 msec difference in performance between the two blocks with neutral items docume...

Watch this Scientific Journal Video about The Emotional Stroop Task: Assessing Cognitive Performance under Exposure to Emotional Content at JoVE.com

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 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 ...

the-emotional-stroop-task-assessing-cognitive-performance-under

Research

JoVE Journal

Behavior

37.9K Views.  Tel-Aviv University. 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.

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

The Crossmodal Congruency Task as a Means to Obtain an Objective Behavioral Measure in the Rubber Hand Illusion Paradigm

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden hand is touched. If the viewed and felt touches are given at the same time then this is sufficient to induce the compelling experience that the rubber hand is one's own hand. The RHI can be used to investigate exactly how the brain constructs distinct body representations for one's own body. Such representations are crucial for successful interactions with the external world. To obtain a subjective measure of the RHI, researchers typically ask participants to rate statements such as "I felt as if the rubber hand were my hand". Here we demonstrate how the crossmodal congruency task can be used to obtain an objective behavioral measure within this paradigm.
The variant of the crossmodal congruency task we employ involves the presentation of tactile targets and visual distractors. Targets and distractors are spatially congruent (i.e. same finger) on some trials and incongruent (i.e. different finger) on others. The difference in performance between incongruent and congruent trials - the crossmodal congruency effect (CCE) - indexes multisensory interactions. Importantly, the CCE is modulated both by viewing a hand as well as the synchrony of viewed and felt touch which are both crucial factors for the RHI.
The use of the crossmodal congruency task within the RHI paradigm has several advantages. It is a simple behavioral measure which can be repeated many times and which can be obtained during the illusion while participants view the artificial hand. Furthermore, this measure is not susceptible to observer and experimenter biases. The combination of the RHI paradigm with the crossmodal congruency task allows in particular for the investigation of multisensory processes which are critical for modulations of body representations as in the RHI.

We demonstrate how an objective measure can be employed in the widely employed rubber hand illusion paradigm. This measure is obtained by modifying the well-established crossmodal congruency task. This task allows the investigation of multisensory processes which are critical for modulations of body representations as in the rubber hand illusion.

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden ...

Assessing Functional Performance in the Mdx Mouse Model

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder for which no cure is available. Nevertheless, several potential pharmaceutical compounds and gene therapy approaches have progressed into clinical trials. With improvement in muscle function being the most important end point in these trials, a lot of emphasis has been placed on setting up reliable, reproducible, and easy to perform functional tests to pre clinically assess muscle function, strength, condition, and coordination in the mdx mouse model for DMD. Both invasive and noninvasive tests are available. Tests that do not exacerbate the disease can be used to determine the natural history of the disease and the effects of therapeutic interventions (e.g. forelimb grip strength test, two different hanging tests using either a wire or a grid and rotarod running). Alternatively, forced treadmill running can be used to enhance disease progression and/or assess protective effects of therapeutic interventions on disease pathology. We here describe how to perform these most commonly used functional tests in a reliable and reproducible manner. Using these protocols based on standard operating procedures enables comparison of data between different laboratories.

Assessing Functional Performance in the Mdx Mouse Model

The primary outcome measure in clinical trials for neuromuscular disorders is generally improved muscle function. Therefore, assessing the effect of potential therapeutic compounds on muscle performance pre clinically in mouse models is of great importance. We here describe several functional tests to address this.

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder for which no cure is available. Nevertheless, several potential ...

Measurement of Fronto-limbic Activity Using an Emotional Oddball Task in Children with Familial High Risk for Schizophrenia

Adolescence is a critical developmental period where the early symptoms of schizophrenia frequently emerge. First-degree relatives of people with schizophrenia who are at familial high risk (FHR) may show similar cognitive and emotional changes. However, the neurological changes underlying the emergence of these symptoms remain unclear. This study sought to identify differences in frontal, striatal, and limbic regions in children and adolescents with FHR using functional magnetic resonance imaging. Groups of 21 children and adolescents at FHR and 21 healthy controls completed an emotional oddball task that relied on selective attention and the suppression of task-irrelevant emotional information. The standard oddball task was modified to include aversive and neutral distractors in order to examine potential group differences in both emotional and executive processing. This task was designed specifically to allow for children and adolescents to complete by keeping the difficulty and emotional image content age-appropriate. Furthermore, we demonstrate a technique for suitable fMRI registration for children and adolescent participants. This paradigm may also be applied in future studies to measure changes in neural activity in other populations with hypothesized developmental changes in executive and emotional processing.

This paper describes how to use the emotional oddball task and fMRI to measure brain activation in children and adolescents at familial high risk for schizophrenia (FHR).&#160;FMRI was used to measure differences in fronto-striato-limbic regions during an emotional oddball task. Children with FHR exhibited abnormal functional activation during adolescence.

Adolescence is a critical developmental period where the early symptoms of schizophrenia frequently emerge. First-degree relatives of people with ...

The Attentional Set Shifting Task: A Measure of Cognitive Flexibility in Mice

Cognitive impairment, particularly involving dysfunction of circuitry within the prefrontal cortex (PFC), represents a core feature of many neuropsychiatric and neurodevelopmental disorders, including depression, post-traumatic stress disorder, schizophrenia and autism spectrum disorder. Deficits in cognitive function also represent the most difficult symptom domain&#160;to successfully treat, as serotonin reuptake inhibitors and tricyclic antidepressants have only modest effects. Functional neuroimaging studies and postmortem analysis of human brain tissue implicate the PFC as being a primary region of dysregulation in patients with these disorders. However, preclinical behavioral assays used to assess these deficits in mouse models which can be readily manipulated genetically and could provide the basis for studies of new treatment avenues have been underutilized. Here we describe the adaptation of a behavioral assay, the attentional set shifting task (AST), to be performed in mice to assess prefrontal cortex mediated cognitive deficits. The neural circuits underlying behavior during the AST are highly conserved across humans, nonhuman primates and rodents, providing excellent face, construct and predictive validity.

The goal of this protocol is to perform a behavioral assay such as the attentional set shifting task (AST) to assess prefrontal cortex-mediated cognitive flexibility in mice.

Cognitive impairment, particularly involving dysfunction of circuitry within the prefrontal cortex (PFC), represents a core feature of many ...

Combined Invasive Subcortical and Non-invasive Surface Neurophysiological Recordings for the Assessment of Cognitive and Emotional Functions in Humans

In spite of the success in applying non-invasive electroencephalography (EEG), magneto-encephalography (MEG) and functional magnetic resonance imaging (fMRI) for extracting crucial information about the mechanism of the human brain, such methods remain insufficient to provide information about physiological processes reflecting cognitive and emotional functions at the subcortical level. In this respect, modern invasive clinical approaches in humans, such as deep brain stimulation (DBS), offer a tremendous possibility to record subcortical brain activity, namely local field potentials (LFPs) representing coherent activity of neural assemblies from localized basal ganglia or thalamic regions. Notwithstanding the fact that invasive approaches in humans are applied only after medical indication and thus recorded data correspond to altered brain circuits, valuable insight can be gained regarding the presence of intact brain functions in relation to brain oscillatory activity and the pathophysiology of disorders in response to experimental cognitive paradigms. In this direction, a growing number of DBS studies in patients with Parkinson&#39;s disease (PD) target not only motor functions but also higher level processes such as emotions, decision-making, attention, memory and sensory perception. Recent clinical trials also emphasize the role of DBS as an alternative treatment in neuropsychiatric disorders ranging from obsessive compulsive disorder (OCD) to chronic disorders of consciousness (DOC). Consequently, we focus on the use of combined invasive (LFP) and non-invasive (EEG) human brain recordings in assessing the role of cortical-subcortical structures in cognitive and emotional processing trough experimental paradigms (e.g. speech stimuli with emotional connotation or paradigms of cognitive control such as the Flanker task), for patients undergoing DBS treatment.

The present protocol aims at assessing cognitive-emotional functions in the basal ganglia by simultaneous neurophysiological recording of local field potentials and non-invasive brain cortical activity (EEG). The procedure is exemplified by the use of paradigms involving speech stimuli with emotional connotation or the Flanker task involving cognitive control.

In spite of the success in applying non-invasive electroencephalography (EEG), magneto-encephalography (MEG) and functional magnetic resonance imaging ...

Conscious and Non-conscious Representations of Emotional Faces in Asperger's Syndrome

Several neuroimaging studies have suggested that the low spatial frequency content in an emotional face mainly activates the amygdala, pulvinar, and superior colliculus especially with fearful faces1-3. These regions constitute the limbic structure in non-conscious perception of emotions and modulate cortical activity either directly or indirectly2. In contrast, the conscious representation of emotions is more pronounced in the anterior cingulate, prefrontal cortex, and somatosensory cortex for directing voluntary attention to details in faces3,4. Asperger&#39;s syndrome (AS)5,6 represents an atypical mental disturbance that affects sensory, affective and communicative abilities, without interfering with normal linguistic skills and intellectual ability. Several studies have found that functional deficits in the neural circuitry important for facial emotion recognition can partly explain social communication failure in patients with AS7-9. In order to clarify the interplay between conscious and non-conscious representations of emotional faces in AS, an EEG experimental protocol is designed with two tasks involving emotionality evaluation of either photograph or line-drawing faces. A pilot study is introduced for selecting face stimuli that minimize the differences in reaction times and scores assigned to facial emotions between the pretested patients with AS and IQ/gender-matched healthy controls. Information from the pretested patients was used to develop the scoring system used for the emotionality evaluation. Research into facial emotions and visual stimuli with different spatial frequency contents has reached discrepant findings depending on the demographic characteristics of participants and task demands2. The experimental protocol is intended to clarify deficits in patients with AS in processing emotional faces when compared with healthy controls by controlling for factors unrelated to recognition of facial emotions, such as task difficulty, IQ and gender.

An EEG experimental protocol is designed to clarify the interplay between conscious and non-conscious representations of emotional faces in patients with Asperger&#39;s syndrome. The technique suggests that patients with Asperger&#39;s syndrome have deficits in non-conscious representation of emotional faces, but have comparable performance in conscious representation with healthy controls.

Several neuroimaging studies have suggested that the low spatial frequency content in an emotional face mainly activates the amygdala, pulvinar, and ...

The Deese-Roediger-McDermott (DRM) Task: A Simple Cognitive Paradigm to Investigate False Memories in the Laboratory

The Deese,&#160;Roediger and McDermott&#160;(DRM) task is a false memory paradigm in which subjects are presented with lists of semantically related words (e.g., nurse, hospital, etc.) at encoding. After a delay, subjects are asked to recall or recognize these words. In the recognition memory version of the task, subjects are asked whether they remember previously presented words, as well as related (but never presented) critical lure words (&#39;doctor&#39;). Typically, the critical word is recognized with high probability and confidence. This false memory effect has been robustly demonstrated across short (e.g., immediate, 20 min) and long (e.g., 1, 7, 60 d) delays between encoding and memory testing. A strength of using this task to study false memory is its simplicity and short duration. If encoding and retrieval components of the task occur in the same session, the entire task can take as little as 2 - 30 min. However, although the DRM task is widely considered a &#39;false memory&#39; paradigm, some researchers consider DRM illusions to be based on the activation of semantic memory networks in the brain, and argue that such semantic gist-based false memory errors may actually be useful in some scenarios (e.g., remembering the forest for the trees; remembering that a word list was about &#34;doctors&#34;, even though the actual word &#34;doctor&#34; was never presented for study). Remembering the gist of experience (instead of or along with individual details) is arguably an adaptive process and this task has provided a great deal of knowledge about the constructive, adaptive nature of memory. Therefore, researchers should use caution when discussing the overall reach and implications of their experiments when using this task to study &#39;false memory&#39;, as DRM memory errors may not adequately reflect false memories in the real world, such as false memory in eyewitness testimony, or false memories of sexual abuse.

The Deese-Roediger-McDermott DRM Task: A Simple Cognitive Paradigm to Investigate False Memories in the Laboratory

Here we present the Deese,&#160;Roediger and McDermott&#160;(DRM) task, a tool to study false memories in the laboratory. Subjects study lists of semantically related words (e.g.,&#160;nurse, sick, etc.), and later falsely remember an unstudied word (doctor) that represents the gist, or theme, of the word list.

The Deese,&#160;Roediger and McDermott&#160;(DRM) task is a false memory paradigm in which subjects are presented with lists of semantically related words ...

Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention

Two dominant theories on lateralized processing of emotional information exist in the literature. One theory posits that unpleasant emotions are processed by right frontal regions, while pleasant emotions are processed by left frontal regions. The other theory posits that the right hemisphere is more specialized for the processing of emotional information overall, particularly in posterior regions.
Assessing the different roles of the cerebral hemispheres in processing emotional information can be difficult without the use of neuroimaging methodologies, which are not accessible or affordable to all scientists. Divided visual field presentation of stimuli can allow for the investigation of lateralized processing of information without the use of neuroimaging technology. 
This study compared central versus divided visual field presentations of emotional images to assess differences in motivated attention between the two hemispheres. The late positive potential (LPP) was recorded using electroencephalography (EEG) and event-related potentials (ERPs) methodologies to assess motivated attention. Future work will pair this paradigm with a more active behavioral task to explore the behavioral impacts on the attentional differences found.

This study compared central versus divided visual field presentations of emotional images to assess differences in motivated attention between the two hemispheres. The late positive potential (LPP) was recorded using electroencephalography (EEG) and event-related potentials (ERPs) methodologies to assess motivated attention.

Two dominant theories on lateralized processing of emotional information exist in the literature. One theory posits that unpleasant emotions are processed ...

The Knob Supination Task: A Semi-automated Method for Assessing Forelimb Function in Rats

Tasks that accurately measure dexterity in animal models are critical to understand hand function. Current rat behavioral tasks that measure dexterity largely use video analysis of reaching or food manipulation. While these tasks are easy to implement and are robust across disease models, they are subjective and laborious for the experimenter. Automating traditional tasks or creating new automated tasks can make the tasks more efficient, objective, and quantitative. Since rats are less dexterous than primates, central nervous system (CNS) injury produces more subtle deficits in dexterity, however, supination is highly affected in rodents and crucial to hand function in primates. Therefore, we designed a semi-automated task that measures forelimb supination in rats. Rats are trained to reach and grasp a knob-shaped manipulandum and turn the manipulandum in supination to receive a reward. Rats can acquire the skill within 20 &plusmn; 5 days. While the early part of training is highly supervised, much of the training is done without direct supervision. The task reliably and reproducibly captures subtle deficits after injury and shows functional recovery that accurately reflects clinical recovery curves. Analysis of data is performed by specialized software through a graphical user interface that is designed to be intuitive. We also give solutions to common problems encountered during training, and show that minor corrections to behavior early in training produce reliable acquisition of supination. Thus, the knob supination task provides efficient and quantitative evaluation of a critical movement for dexterity in rats.

This manuscript describes a semi-automated task that quantifies supination in rats. Rats reach, grasp, and supinate a spherical manipulandum. The rat is rewarded with a pellet if the turn angle exceeds a criterion set by the user. This task increases throughput, sensitivity to injury, and objectivity compared to traditional tasks.

Tasks that accurately measure dexterity in animal models are critical to understand hand function. Current rat behavioral tasks that measure dexterity ...

The "Motor" in Implicit Motor Sequence Learning: A Foot-stepping Serial Reaction Time Task

This protocol describes a modified serial reaction time (SRT) task used to study implicit motor sequence learning. Unlike the classic SRT task that involves finger-pressing movements while sitting, the modified SRT task requires participants to step with both feet while maintaining a standing posture. This stepping task necessitates whole body actions that impose postural challenges. The foot-stepping task complements the classic SRT task in several ways. The foot-stepping SRT task is a better proxy for the daily activities that require ongoing postural control, and thus may help us better understand sequence learning in real-life situations. In addition, response time serves as an indicator of sequence learning in the classic SRT task, but it is unclear whether response time, reaction time (RT) representing mental process, or movement time (MT) reflecting the movement itself, is a key player in motor sequence learning. The foot-stepping SRT task allows researchers to disentangle response time into RT and MT, which may clarify how motor planning and movement execution are involved in sequence learning. Lastly, postural control and cognition are interactively related, but little is known about how postural control interacts with learning motor sequences. With a motion capture system, the movement of the whole body (e.g., the center of mass (COM)) can be recorded. Such measures allow us to reveal the dynamic processes underlying discrete responses measured by RT and MT, and may aid in elucidating the relationship between postural control and the explicit and implicit processes involved in sequence learning. Details of the experimental set-up, procedure, and data processing are described. The representative data are adopted from one of our previous studies. Results are related to response time, RT, and MT, as well as the relationship between the anticipatory postural response and the explicit processes involved in implicit motor sequence learning.

We introduce the foot-stepping serial reaction time (SRT) task. This modified SRT task, complementing the classic SRT task that involves only finger-pressing movement, better approximates daily sequenced activities and allows researchers to study the dynamic processes underlying discrete response measures and disentangle the explicit process operating in implicit sequence learning.

This protocol describes a modified serial reaction time (SRT) task used to study implicit motor sequence learning. Unlike the classic SRT task that ...