Name: dissociation of the confounding influences of expectancy and integrative difficulty residing in anomalous sentences in event-related potential studies
Uploaded: 2019-05-09T14:00:00
Description: Watch this Scientific Journal Video about Dissociation of the Confounding Influences of Expectancy and Integrative Difficulty Residing in Anomalous Sentences in Event-related Potential Studies at JoVE

This work was supported by the National Natural Science Foundation of China [61433015], National Social Science Major Fund of China[14ZDB154; 15ZDB017], and the MOE (Ministry of Education in China) Project of Humanities and Social Sciences [14YJC740104]. We express great gratitude to the two anonymous reviewers for their valuable suggestions.

The present protocol was approved by the Institutional Review Board of Tsinghua University.
1. Stimuli construction
<ol>
	<li>Construct critical anomalous sentences for the repetition and non-repetition groups
	<ol>
		<li>Prepare an adequate number of correct sentences for the construction of anomalous sentences (no less than 40). For example, &#8220;These two components were separated by a centrifugal device.&#8221; Try to use only emotion-free sentences as...

<ol>
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F., Phillips, C., Poeppel, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+cortical+network+for+semantics:+(de)constructing+the+N400.">A cortical network for semantics: (de)constructing the N400.</a> Nature Reviews Neuroscience. 9, 920-933 (2008).</li><li>Baggio, G., Hagoort, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+balance+between+memory+and+unification+in+semantics:+A+dynamic+account+of+the+N400.">The balance between memory and unification in semantics: A dynamic account of the N400.</a> Language and Cognitive Processes. 26, 1338-1367 (2011).</li><li>Steinhauer, K., Phaedra, R., John, E. D., Fromont, L. 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G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=N400+amplitude+does+not+recover+from+disappearance+after+repetitions+despite+reinitiated+semantic+integration+difficulty.">N400 amplitude does not recover from disappearance after repetitions despite reinitiated semantic integration difficulty.</a> Neuroreport. 29, 1341-1348 (2018).</li><li>Brouwer, H., Crocker, M. W., Venhuizen, N. J., Hoeks, J. C. 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Experimental results and significance 
In the repetition part, the results demonstrated that the N400 effect became smaller and smaller until almost non-existent. The greatly attenuated N400 effect proved that multiple repetitions did significantly modulate the amplitude of N400. However, the results in this part cannot show whether N400 was actually affected by the change of expectancy or semantic integration. The attenuated N400 effect can still be explained differently. One explanation is that ex...

Anomalous sentences are widely used by linguists to study online cognitive processing of normal languages. For example, in event-related potentials (ERP) studies, sentences with semantic anomalies (e.g., &#34;He spread the warm bread with socks.&#34;) were reported to elicit an N400 effect1 (but also see some other studies reporting a semantic P600 effect2,3), while sentences with syntactic difficulties or anomalies (e.g., &#34;The woman persuaded to answer the door&#8230;&#34;) were reported to elicit a P600 effect4,5. These electrophysiological components are widely used as reliable indicators for investigating the normal temporal courses of processing information from different aspects of language, such as syntax and semantics.
Anomalous sentences cause great difficulties for semantic integration processing during comprehension. However, confounding factors such as unexpectedness (i.e., any anomalous expression is naturally an unexpected expression) make it difficult to determine the true cognitive process underlying the observed effect elicited by anomalous sentences. For example, if an N400 effect is elicited by an anomalous sentence, it is unclear whether it is caused by unexpectedness6,7,8 or integrative difficulty1,9,10.
To ascertain whether it is expectancy or semantic integration difficulty that contributes to the elicited electrophysiological effect, we need to dissociate these two factors. Traditionally, expectancy is often measured by corpus frequency (in word studies) or cloze probability (in sentence studies). The widely applied method to manipulate expectancy in traditional experiments is by choosing stimuli with high and low scores in expectancy to form expected and unexpected groups. This method is effective in manipulating expectancy and has produced abundant insightful results.
However, as a static approach to manipulating expectancy, it has one limitation: it is hard for the expected and unexpected groups to have the same semantic integration difficulty. With this manipulation, the stimuli selected for the expected and unexpected groups have to be different; thus the semantic integration difficulty is altered when we manipulate expectancy by using different stimuli with different expectancy values or cloze probabilities). While we may find unexpected but reasonable expressions (i.e., unexpected expressions made up of words that can be successfully integrated into a reasonable message), it is possible that the integrative efforts required by these unexpected but reasonable expressions are different from those required by normal expressions. If the differences are not controlled, significant differences in brain responses might ensue, as clear evidence demonstrates that the integrative processing of unexpected but reasonable new metaphorical expressions triggers brain responses quite different from those triggered by conventional metaphors11,12.
To address this issue, we propose a new method to dynamically enhance participants&#39; expectancy for anomalous sentences while trying to maintain the semantic integration difficulty. Specifically, we quickly familiarize participants with unfamiliar anomalous sentences and thus enhance their expectancy through multiple repetitions. Importantly, multiple repetitions do not change the stimulus itself; therefore, the semantically anomalous information itself remains unchanged (i.e., the critical word still cannot be successfully integrated into the context).
However, the brain might give up integration after learning that the anomalous information cannot be successfully integrated into the previous context at all (i.e., the integration processing might be absent so that there is no integration difficulty). Therefore, this protocol proposes to repeat only the core anomalous information extracted from the anomalous sentence first, and then use the complete anomalous sentence which contains the identical anomalous information as a semantically enriched version of this core anomalous information, to initiate new semantic integration processing in the repetition condition. With the identical anomalous information in the semantically enriched complete anomalous sentence and the initiated new semantic integration processing, we assume that the semantic integration difficulty triggered by the anomalous information in the complete anomalous sentence after multiple repetitions should remain almost the same as that triggered by the anomalous information before repetitions (regardless of the status of semantic integration processing during repetitions). Hence, we assume the factor of semantic integration difficulty in the semantically enriched complete anomalous sentences remains the same after repetitions as in the correspondingly simplified core structures, but the expectancy is greatly enhanced.
Based on these assumptions, we compare the N400 effect elicited by semantically enriched complete anomalous sentences containing the repeated core anomalous information with that elicited by newly-met complete anomalous sentences, to investigate the major contributor of this elicited ERP effect. The working hypotheses are as follows: according to previous studies, the N400 effect would be significantly attenuated by repetitions. On the basis of the attenuated N400, if the newly initiated semantic integration of the same anomalous information causes recovery of the attenuated N400 effect to a level similar to that elicited by the same type of anomalous information contained in newly-met anomalous sentences with no repetitions, then it suggests that the semantic integration difficulty is the dominant contributor of the elicited N400 effect; otherwise it suggests that unexpectedness is the major contributor.

<table>
	<tbody>
		<tr>
			<td>BrainAmp DC amplifier system (Brain Products GmbH)</td>
			<td>Brain Products, Gilching, Germany</td>
			<td></td>
			<td>BrainAmp S/N AMP13061964DC Input 5.6DC=150mA Operation 7mA Standby</td>
		</tr>
		<tr>
			<td>Easycap (Brain Products GmbH)</td>
			<td>Brain Products, Gilching, Germany</td>
			<td></td>
			<td>62 
			Ag/AgCl electrodes with a configuration 
			of the international 10&#8211;20 system of electrode</td>
		</tr>
	</tbody>
</table>

dissociation of the confounding influences of expectancy and integrative difficulty residing in anomalous sentences in event-related potential studies

The confounding factors of unexpectedness and semantic integration difficulty naturally residing in anomalous sentences in language studies make it difficult to determine the underlying processing mechanism of ERP components. Unlike the traditional static approach of manipulating expectancy through corpus frequency or cloze probability, this protocol proposes a dynamic method to enhance participants&#39; expectancy for rarely-met anomalous sentences by multiple repetitions while maintaining their semantic integration difficulties. To address the time cost increase resulting from multiple repetitions, this protocol proposes to repeat only the strictly simplified core structure extracted from the anomalous sentence before presenting the semantically enriched, much more informative complete anomalous sentence containing the anomalous core structure to reinitiate the semantic integration processing. The complete anomalous sentence elicited a P600 effect. It suggests that the participants did not give up processing the anomalous information after repetitions and the same semantic integration difficulty was successfully reinitiated. Importantly, the representative experimental results reveal that the greatly attenuated N400 effect caused by multiple repetitions was not recovered by the follow-up reinitiated semantic integration difficulty. It suggests that the attenuated N400 effect should be mainly attributed to the enhancement of expectancy for anomalous information by multiple repetitions. The experimental results show that this method can effectively enhance participants&#39; expectancy for anomalous sentences while retaining the semantic integration difficulty.

The present protocol was used in one of our recent studies to investigate whether the N400 effect reflects semantic integration processing14. The stimuli used in that study were in Chinese, as shown in Table 2.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td colspan="3">(a) Example of the simplified core structures in the repetition part</td>
		</tr>
		<tr>
			<td></td>
			<td>Im...

Watch this Scientific Journal Video about Dissociation of the Confounding Influences of Expectancy and Integrative Difficulty Residing in Anomalous Sentences in Event-related Potential Studies at JoVE

Dissociation of the Confounding Influences of Expectancy and Integrative Difficulty Residing in Anomalous Sentences in Event-related Potential Studies

We present a protocol to dissociate the intertwining factors of integrative difficulty and unexpectedness in semantically anomalous sentences by applying multiple repetitions to enhance participant&#39;s expectancy for anomalous sentences. The dissociation helps to investigate the major contributor of elicited event-related potentials (ERP) effects such as N400 in language studies.

The confounding factors of unexpectedness and semantic integration difficulty naturally residing in anomalous sentences in language studies make it ...

This protocol provides an effective way to dissociate the confounding factors of unexpectedness in intuitive difficulty in anomalous sentences to determine the real contributor of N400 effect in language studies. Unlike the traditional static approach of manipulating expectancy through corpus frequency or cloze probability. This protocol proposed a dynamic mission to achieve this goal by multiple repetitions.With this protocol, we can also examine how other ERP components, such as P600, may respond to multiple repetitions. It may help to reveal the underlying mechanism of P600 as well. Begin by escorting the patient to the testing room and have them sit comfortably in a chair.Then prep the participant's skin with facial scrub and a cotton-swab on the forehead, under the left eye, near the outer canthus of the right eye, and around the left and right mastoid bone. Place the elastic cap with electrodes on the participant's head. Ensure that the CZ electrode on the cap is located at the vertex of the head and the cap has a left-right symmetry with midline electrodes placed over the midline of the head.Next, stick the adhesive tape to the electrodes that record eye movements and fill them with conductive gel. Fix the one electrode at the outer canthus of the right eye and the other below the left eye. Then fasten the strap under the chin to prevent the adjacent electrodes from moving during the experiment and connect the cap electrodes to the recording system.Finally, to reduce the impedance of all electrodes below five kilohms or 10 kilohms, switch the recording software to the impedance monitoring interface. Then starting with the ground and reference electrodes, past the blunt tip needle of the syringe containing conductive gel through the eyelets of the electrodes and hairs until it reaches the skin of the scalp. Push the syringe plunger to inject a small dose of the conducting gel onto to the skin until the gel connects the metal circle on the electrode and the skin.Finally, check the real time impedance level displayed in different colors on the monitor until the impedance decreases to below the threshold value. Check all electrodes. Begin by asking the participant to relax and try to avoid excessive eye blinks and body movements during the experiment.Inform the participant about the tasks and the repetition part in the tasks in the main sentence part. Ensure the participant understands that an incorrect sentence will be followed by a repetition part and a correct sentence by another complete sentence, which may be correct or incorrect. Then start the stimuli presentation program, and let the participant practice with the practicing section.For the repetition part, present the extracted core structure and its correct filler expression together seven times in a random order. For the semantic re-initiating complete sentence, present the complete anomalous sentence right after its corresponding repetition part. After the practice session is complete, begin the formal experimental session and record the electric physiological signals.Finally, after the experiment is complete, save the recorded electric physiological data and help the participant take off the cap. Instruct the participant to wash away the conductive gel on the skin and hair and provide them with a reward for their participation. The 11 related potentials were ERPs in the first time, the fourth time, and the seventh time presentation of the anomalous core structures revealed that the N400 effect in the 300-500 millisecond time window disappeared gradually.ERPs in the unrepeated anomalous sentence group were more negative than those in the control group. ERPs in the repeated group were more positive than those in the unrepeated group. Remember to place all electrodes at the right location impedance of all electrodes below five kilohm or 10 kilohm before the experiment.This protocol effectively limits the time of repeating sentences for multiple trials. Multiple repetitions of sentences may help to reveal the real memory in sentence comprehension.

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Research

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Behavior

A Procedure to Study the Effect of Prolonged Food Restriction on Heroin Seeking in Abstinent Rats

In human drug addicts, exposure to drug-associated cues or environments that were previously associated with drug taking can trigger relapse during abstinence. Moreover, various environmental challenges can exacerbate this effect, as well as increase ongoing drug intake.
The procedure we describe here highlights the impact of a common environmental challenge, food restriction, on drug craving that is expressed as an augmentation of drug seeking in abstinent rats.
Rats are implanted with chronic intravenous i.v. catheters, and then trained to press a lever for i.v. heroin over a period of 10-12 days. Following the heroin self-administration phase the rats are removed from the operant conditioning chambers and housed in the animal care facility for a period of at least 14 days. While one group is maintained under unrestricted access to food (sated group), a second group (FDR group) is exposed to a mild food restriction regimen that results in their body weights maintained at 90% of their nonrestricted body weight. On day 14 of food restriction the rats are transferred back to the drug-training environment, and a drug-seeking test is run under extinction conditions (i.e.&#160;lever presses do not result in heroin delivery).
The procedure presented here results in a highly robust augmentation of heroin seeking on test day in the food restricted rats. In addition, compared to the acute food deprivation manipulations we have used before, the current procedure is a more clinically relevant model for the impact of caloric restriction on drug seeking. Moreover, it might be closer to the human condition as the rats are not required to go through an extinction-training phase before the drug-seeking test, which is an integral component of the popular reinstatement procedure.

A procedure that allows a demonstration of robust augmentation of drug seeking in food-restricted rats is described. Following heroin self-administration training, rats go through an abstinence period, in a drug-free environment, during which they are mildly food restricted. Drug seeking is then tested in the drug-associated environment.

In human drug addicts, exposure to drug-associated cues or environments that were previously associated with drug taking can trigger relapse during ...

A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate drug-seeking behavior and prompt relapse in abstinent drug users. We have developed a procedure to study the behavioral and neural processes that mediate the impact of context on alcohol-seeking behavior in rats. Following acclimation to the taste and pharmacological effects of 15% ethanol in the home cage, male Long-Evans rats receive Pavlovian discrimination training (PDT) in conditioning chambers. In each daily (Mon-Fri) PDT session, 16 trials each of two different 10 sec auditory conditioned stimuli occur. During one stimulus, the CS+, 0.2 ml of 15% ethanol is delivered into a fluid port for oral consumption. The second stimulus, the CS-, is not paired with ethanol. Across sessions, entries into the fluid port during the CS+ increase, whereas entries during the CS- stabilize at a lower level, indicating that a predictive association between the CS+ and ethanol is acquired. During PDT each chamber is equipped with a specific configuration of visual, olfactory and tactile contextual stimuli. Following PDT, extinction training is conducted in the same chamber that is now equipped with a different configuration of contextual stimuli. The CS+ and CS- are presented as before, but ethanol is withheld, which causes a gradual decline in port entries during the CS+. At test, rats are placed back into the PDT context and presented with the CS+ and CS- as before, but without ethanol. This manipulation triggers a robust and selective increase in the number of port entries made during the alcohol predictive CS+, with no change in responding during the CS-. This effect, referred to as context-induced renewal, illustrates the powerful capacity of contexts associated with alcohol consumption to stimulate alcohol-seeking behavior in response to Pavlovian alcohol cues.

A procedure to study the capacity of an alcohol associated environmental context to trigger the renewal of alcohol-seeking behavior in rats is described.

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate ...

Measuring Neural and Behavioral Activity During Ongoing Computerized Social Interactions: An Examination of Event-Related Brain Potentials

Social exclusion is a complex social phenomenon with powerful negative consequences. Given the impact of social exclusion on mental and emotional health, an understanding of how perceptions of social exclusion develop over the course of a social interaction is important for advancing treatments aimed at lessening the harmful costs of being excluded. To date, most scientific examinations of social exclusion have looked at exclusion after a social interaction has been completed. While this has been very helpful in developing an understanding of what happens to a person following exclusion, it has not helped to clarify the moment-to-moment dynamics of the process of social exclusion. Accordingly, the current protocol was developed to obtain an improved understanding of social exclusion by examining the patterns of event-related brain activation that are present during social interactions. This protocol allows greater precision and sensitivity in detailing the social processes that lead people to feel as though they have been excluded from a social interaction. Importantly, the current protocol can be adapted to include research projects that vary the nature of exclusionary social interactions by altering how frequently participants are included, how long the periods of exclusion will last in each interaction, and when exclusion will take place during the social interactions. Further, the current protocol can be used to examine variables and constructs beyond those related to social exclusion. This capability to address a variety of applications across psychology by obtaining both neural and behavioral data during ongoing social interactions suggests the present protocol could be at the core of a developing area of scientific inquiry related to social interactions.

Research on social exclusion has grown tremendously in recent years. As the field expands, it is imperative to develop sophisticated methodologies allowing for the simultaneous measurement of neural and behavioral outcomes during social exclusion. This protocol utilizes event-related brain potentials to record ongoing neural activity during computerized social interactions.

Social exclusion is a complex social phenomenon with powerful negative consequences. Given the impact of social exclusion on mental and emotional health, ...

Investigating the Effects of Antipsychotics and Schizotypy on the N400 Using Event-Related Potentials and Semantic Categorization

Within the field of cognitive neuroscience, functional magnetic resonance imaging (fMRI) is a popular method of visualizing brain function. This is in part because of its excellent spatial resolution, which allows researchers to identify brain areas associated with specific cognitive processes. However, in the quest to localize brain functions, it is relevant to note that many cognitive, sensory, and motor processes have temporal distinctions that are imperative to capture, an aspect that is left unfulfilled by fMRI&#8217;s suboptimal temporal resolution. To better understand cognitive processes, it is thus advantageous to utilize event-related potential (ERP) recording as a method of gathering information about the brain. Some of its advantages include its fantastic temporal resolution, which gives researchers the ability to follow the activity of the brain down to the millisecond. It also directly indexes both excitatory and inhibitory post-synaptic potentials by which most brain computations are performed. This sits in contrast to fMRI, which captures an index of metabolic activity. Further, the non-invasive ERP method does not require a contrast condition: raw ERPs can be examined for just one experimental condition, a distinction from fMRI where control conditions must be subtracted from the experimental condition, leading to uncertainty in associating observations with experimental or contrast conditions. While it is limited by its poor spatial and subcortical activity resolution, ERP recordings&#8217; utility, relative cost-effectiveness, and associated advantages offer strong rationale for its use in cognitive neuroscience to track rapid temporal changes in neural activity. In an effort to foster increase in its use as a research imaging method, and to ensure proper and accurate data collection, the present article will outline &#8211; in the framework of a paradigm using semantic categorization to examine the effects of antipsychotics and schizotypy on the N400 &#8211; the procedure and key aspects associated with ERP data acquisition.

Using event-related EEG potentials (ERPs), we investigate the effects of antipsychotic medications on abnormal semantic brain activations in healthy individuals with schizotypal traits. We use ERPs to track distinct changes in brain activity, shedding insight into the cognitive processes associated with semantic categorization.

Within the field of cognitive neuroscience, functional magnetic resonance imaging (fMRI) is a popular method of visualizing brain function. This is in ...

Infant Auditory Processing and Event-related Brain Oscillations

Rapid auditory processing and acoustic change detection abilities play a critical role in allowing human infants to efficiently process the fine spectral and temporal changes that are characteristic of human language. These abilities lay the foundation for effective language acquisition; allowing infants to hone in on the sounds of their native language. Invasive procedures in animals and scalp-recorded potentials from human adults suggest that simultaneous, rhythmic activity (oscillations) between and within brain regions are fundamental to sensory development; determining the resolution with which incoming stimuli are parsed. At this time, little is known about oscillatory dynamics in human infant development. However, animal neurophysiology and adult EEG data provide the basis for a strong hypothesis that rapid auditory processing in infants is mediated by oscillatory synchrony in discrete frequency bands. In order to investigate this, 128-channel, high-density EEG responses of 4-month old infants to frequency change in tone pairs, presented in two rate conditions (Rapid: 70 msec ISI and Control: 300 msec ISI) were examined. To determine the frequency band and magnitude of activity, auditory evoked response averages were first co-registered with age-appropriate brain templates. Next, the principal components of the response were identified and localized using a two-dipole model of brain activity. Single-trial analysis of oscillatory power showed a robust index of frequency change processing in bursts of Theta band (3 - 8 Hz) activity in both right and left auditory cortices, with left activation more prominent in the Rapid condition. These methods have produced data that are not only some of the first reported evoked oscillations analyses in infants, but are also, importantly, the product of a well-established method of recording and analyzing clean, meticulously collected, infant EEG and ERPs. In this article, we describe our method for infant EEG net application, recording, dynamic brain response analysis, and representative results.

High-density electroencephalography (dEEG) is being used increasingly to study brain development and plasticity in the early years of life. Here we present an application of sophisticated analysis techniques that builds on traditional EEG recording to understand the oscillatory dynamics of rapid auditory processing in the infant brain.

Rapid auditory processing and acoustic change detection abilities play a critical role in allowing human infants to efficiently process the fine spectral ...

The Social Dimension of Stress: Experimental Manipulations of Social Support and Social Identity in the Trier Social Stress Test

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations supportive behavior of other people as well as positive social relationships can act as powerful resources to cope with stress. In order to study the interplay between these variables, this protocol describes two effective experimental manipulations of social relationships and supportive behavior in the laboratory. In the present article, these two manipulations are implemented in the Trier Social Stress Test (TSST)&#8212;a standard stress induction paradigm in which participants are subjected to a simulated job interview. More precisely, we propose (a) a manipulation of the relationship between different protagonists in the TSST by making a shared social identity salient and (b) a manipulation of the behavior of the TSST-selection committee, which acts either supportively or unsupportively. These two experimental manipulations are designed in a modular fashion and can be applied independently of each other but can also be combined. Moreover, these two manipulations can also be integrated into other stress protocols and into other standardized social interactions such as trust games, negotiation tasks, or other group tasks.

Previous research on the social dimension of stress has focused on two important variables: social identity and social support. This protocol introduces an effective experimental manipulation of these two social variables and describes their implementation in a standard stress induction paradigm (Trier Social Stress Test).

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations ...

Event-related Potentials During Target-response Tasks to Study Cognitive Processes of Upper Limb Use in Children with Unilateral Cerebral Palsy

Unilateral Cerebral Palsy (CP) is a neurodevelopmental disorder that is a very common cause of disability in childhood. It is characterized by unilateral motor impairments that are frequently dominated in the upper limb. In addition to a reduced movement capacity of the affected upper limb, several children with unilateral CP show a reduced awareness of the remaining movement capacity of that limb. This phenomenon of disregarding the preserved capacity of the affected upper limb is regularly referred to as Developmental Disregard (DD). Different theories have been postulated to explain DD, each suggesting slightly different guidelines for therapy. Still, cognitive processes that might additionally contribute to DD in children with unilateral CP have never been directly studied. The current protocol was developed to study cognitive aspects involved in upper limb control in children with unilateral CP with and without DD. This was done by recording event-related potentials (ERPs) extracted from the ongoing EEG during target-response tasks asking for a hand-movement response. ERPs consist of several components, each of them associated with a well-defined cognitive process (e.g., the N1 with early attention processes, the N2 with cognitive control and the P3 with cognitive load and mental effort). Due to its excellent temporal resolution, the ERP technique enables to study several covert cognitive processes preceding overt motor responses and thus allows insight into the cognitive processes that might contribute to the phenomenon of DD. Using this protocol adds a new level of explanation to existing behavioral studies and opens new avenues to the broader implementation of research on cognitive aspects of developmental movement restrictions in children.

Several children with unilateral Cerebral Palsy seem to disregard the preserved capacity of their affected upper limb. This Developmental Disregard is extensively described in the literature but the involved cognitive processes have not been studied. To study underlying cognitive factors of upper limb control, an event-related potential protocol was developed.

Unilateral Cerebral Palsy (CP) is a neurodevelopmental disorder that is a very common cause of disability in childhood. It is characterized by unilateral ...

A Semantic Priming Event-related Potential (ERP) Task to Study Lexico-semantic and Visuo-semantic Processing in Autism Spectrum Disorder

Individuals with autism spectrum disorder (ASD) have characteristic deficits in understanding the meaning of language, or semantic processing. However, some evidence indicates that semantic processing of non-linguistic stimuli is intact, suggesting that semantic deficits may be language-specific. To appropriately characterize semantic processing deficits in individuals with ASD, comparison of within-modality linguistic (e.g., written words) and non-linguistic (e.g., pictures) stimuli is required. This paper describes such a methodology that makes use of a semantic priming paradigm during concurrent recording of electroencephalographic (EEG) data. EEG provides a dynamic measure of brain activity that is well-suited to characterize subtle differences in semantic processing that may not be observable at the behavioral level. The semantic priming paradigm presents a prime picture or word (e.g., dog) followed by a target picture or word that is either related (e.g., cat) or unrelated (e.g., pencil) to the prime. This paradigm can thus be used to evaluate semantic processing across different modalities, and to compare lexico-semantic and visuo-semantic processing abilities in individuals with ASD and how they might differ from TD individuals. The specific steps involved in creating the stimuli, performing the EEG testing, and analyzing the EEG data are discussed. Representative results illustrate how the N400 component of the event-related potential (ERP) is reduced following semantically-related prime-target pairs compared to unrelated pairs. Comparisons of the N400 between conditions, modalities, and groups can provide estimates of the success of semantic processing, and can thereby be used to characterize semantic deficits in individuals with ASD or other clinical populations.

A Semantic Priming Event-related Potential ERP Task to Study Lexico-semantic and Visuo-semantic Processing in Autism Spectrum Disorder

This paper describes a semantic priming ERP task using within-modality pairs of pictures and words to investigate semantic processing in individuals with autism spectrum disorder (ASD).

Individuals with autism spectrum disorder (ASD) have characteristic deficits in understanding the meaning of language, or semantic processing. However, ...

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 ...

In Vivo Protocol of Controlled Subconcussive Head Impacts for the Validation of Field Study Data

Subconcussive hits pose a threat to neuronal health as they have shown to induce neuronal structural damage and functional impairment without causing outward symptomology and appear to be a key contributor to an irreversible neurodegenerative disease, chronic traumatic encephalopathy (CTE). In addition, athletes can incur more than 1,000 of these hits per season. The subconcussive soccer heading model (SSHM) is a relevant, reproducible, and leading method of isolating and examining the effects of these subconcussive head impacts. By controlling variables such as ball traveling speed, the frequency of impacts, interval, ball placement to the head, as well as by measuring head impact magnitude, the SSHM provides the scientific community with a superior avenue of investigating the acute subconcussive effects on neuronal health. In this paper, we demonstrate the utility of SSHM in studying a time-course expression of neurofilament-light polypeptide (NF-L) in plasma in a repeated measures fashion. NF-L is an axonal injury marker that has previously been shown to be elevated in boxers and football players following subconcussive head trauma. Thirty-four adult aged soccer players were recruited and randomly assigned to either a soccer heading (n = 18) or kicking (n = 16) group. The heading group executed 10 headers with soccer balls projected at a velocity of 25 mph over 10 min. The kicking group followed the same protocol with 10 kicks. Plasma samples were obtained before and at 0 h, 2 h, and 24 h after heading/kicking and assessed for NF-L expressions. The heading group showed a gradual increase in plasma NF-L expression and peaked at 24 h after the heading protocol, whereas the kicking group remained consistent across the time points. These results confirmed the NF-L data from clinical field studies, encouraging the use of SSHM to validate clinical subconcussion data.

The subconcussive soccer heading model is a safe and concise methodological approach to isolate and measure the effects of subconcussive head impacts.

Subconcussive hits pose a threat to neuronal health as they have shown to induce neuronal structural damage and functional impairment without causing ...