This research was made possible with the support of grants from the National Science and Engineering Research Council (NSERC) to J. Bruce Morton.

1. Obtain Approval for Working with Human Subjects
2. fMRI Data Acquisition
<ol>
	<li>Acquire fMRI data following procedures suitable for young children (see Raschle, et al.12). Make every effort to limit possible age-related differences in task performance and motion, as these differences introduce unwanted confounds that limit one&#39;s capacity to draw inferences about developmentally-relevant differences in brain activation and functional connectivity. 
	Note: In the current protocol, a repeated-trials version of the DCCS was administered in the form of a block design13. Each run includes two 8-trial switch blocks and two 8-trial repeat blocks, where switch blocks consist of 4 switch trials and 4 repeat trials, and repeat blocks consist of 8 repeat trials. The protocol is perfectly suitable for use with event-related fMRI data. However, block designs are nice to work with when first getting acquainted with ICA, as it is easy to see task modulations in the component time courses.</li>
	<li>Preprocess fMRI data following standard fMRI preprocessing procedures.
	<ol>
		<li>Realign all functional images to the same orientation and position. Typically, the first functional volume is used as a reference image for all other volumes to be aligned to.</li>
		<li>Coregister the T1-weighted (anatomical) image with the T2*-weighted (functional) scans, so that activation is superimposed onto the correct anatomical location.</li>
		<li>Normalize all of the images to a standardized size, space, and position with the selection of a template brain (e.g. Talairach space). This helps to ensure that homologous regions from different subjects are being compared. 
		Note: Images are warped to Talairach space in the current protocol, although other templates may also be used (for example, MNI {Montreal Neurological Institute} space).</li>
		<li>Smooth all functional volumes in the data set with a 6&#160;&#160;to 10&#160;mm smoothing kernel.</li>
	</ol>
	</li>
	<li>Sequester preprocessed volumes into a separate set of directories. Use &#34;Functional scans&#34; as the top directory. Within &#34;Functional scans&#34; include a separate directory for each participant, and within each participant directory, a separate directory for each run. The data is now ready for ICA analysis.</li>
</ol>
3. Group&#160;Independent Component Analysis (ICA)
<ol>
	<li>Download and install group ICA software. There are a number of toolboxes available for implementing ICA on different types of neurophysiological data, including fMRI. While any toolbox that performs group ICA would potentially be suitable, the one utilized in the current protocol is called GIFT. GIFT was developed by Vince Calhoun and colleagues at the University of New Mexico. The GIFT toolbox is a set of MATLAB scripts that works together with SPM, a well-known fMRI analysis package. Both can be downloaded for free from the internet (GIFT: mialab.mrn.org/software/gift/index.html#; SPM: www.fil.ion.ucl.ac.uk/spm/).&#160;Once downloaded, add the GIFT toolbox and all sub-directories to the MATLAB search path and save path file.</li>
	<li>Computing a group ICA on fMRI data using GIFT makes substantial demands on RAM memory. The precise demands on memory will vary depending on the number of participants, the amount of data collected from each participant, and the resolution of the data. To avoid memory issues, it is best to run the ICA analysis on a server. If running the analysis on a local computer, the RAM requirements can be estimated through the use of a script &#34;icatb_mem_ica.m&#34; that is part of GIFT.</li>
	<li>Set-up or parameterize the analysis. Do this by modifying a pre-existing batch script called &#34;Input_data_subjects_1.m&#34; that is stored in GIFT under &#34;icatb_batch_files&#34;. 
	Note: This can also be done by using GIFT&#39;s Graphical User Interface. However, it is much easier, with a bit of practice, to set up the analysis by modifying this pre-existing script.
	<ol>
		<li>Specify data modality as fMRI</li>
		<li>Specify Type of Analysis as ICA with ICASSO. This will ensure the ICA is run with the ICASSO procedure. ICASSO estimates the reliability of the decomposition by running the ICA several times starting with different random seeds. It then tests the similarity of each result by means of clustering. Use of ICASSO is recommended as mean of checking the quality of the ICA decomposition, but will considerably extend the time it takes GIFT to complete the analysis.
		<ol>
			<li>To run the ICA with the ICASSO procedure, select &#39;2&#39; under &#34;Type of analysis&#34; and then parameterize the ICASSO procedure in the succeeding lines of the setup file.</li>
		</ol>
		</li>
		<li>Maximize the performance of the group PCA by choosing &#39;1&#39; under Group PCA performance settings. Consider setting this parameter to &#39;2&#39; should problems of insufficient RAM memory occur.</li>
		<li>To enable later sorting of resulting components using predictors from a standard SPM design matrix, specify whether or not there are different matrices for different subjects.</li>
		<li>Specify where the preprocessed functional data are stored and whether an SPM.mat file containing the design matrix is stored together with the preprocessed functional data.
		<ol>
			<li>The most straightforward way of getting GIFT to read the data is if every participant has the same number of runs, and the data directory is structured as described in Step 2.3 under fMRI data acquisition. If so, then under DataSelectionMethod, chose &#39;1&#39; for Method 1, and complete the parameter &#34;sourceDir_filePattern_flagLocation&#34; by including the filepath where the data are stored, the file format of the data, and a statement indicating that individual sessions are stored as subdirectories within each subject folder.</li>
		</ol>
		</li>
		<li>Indicate the directory where the output of the analysis should be written. Do not write the results to the same directory where the data are stored.</li>
		<li>Provide a prefix that will be added to all output files.</li>
		<li>Provide a filepath to a mask. All volumes submitted to ICA are masked. GIFT provides a default mask. For this work, an in-house script to generate a mask from the data that will be submitted to ICA. At a minimum, the mask should eliminate skull, extra-cerebral space, and especially the eyeballs. Signal from eyeball voxels will show very large fluctuations during a run and will therefore have a sizable influence on the structure of the final components. Figure 3&#160;illustrates what a good mask should look like.</li>
		<li>Specify the type of group PCA to be used. Use &#39;subject specific.&#39;</li>
		<li>Specify the back-reconstruction method. In this stage, individual subject IC&#39;s and their associated time courses are computed from the results of the group analysis. GICA is recommended for obtaining the best time courses, although there is considerable discussion in the literature on this point.</li>
		<li>Specify data pre-processing type. Use intensity normalization to avoid non-numerical values (i.e.&#160;infinites, and NaN&#39;s) in the output. In this example, we chose the default of &#39;1&#39;.</li>
		<li>Specify the type of PCA (we use standard) and accept default values under PCA Options. GIFT performs a PCA on each run of each participant and retains a number of components equal to the number of sources to be unmixed in the ICA. The PCA serves two important purposes. First, it helps to eliminate sources of noise that are unique to each participant and each run. Second, it makes the computational demands of the analysis more tractable.</li>
		<li>Specify how many PCAs to run on the data before the ICA (2 is recommended). As well, specify how many components to retain after each PCA (if running 2, it is recommended that the number of components retained after the first PCA is twice the number retained after the second).</li>
		<li>Specify how the data should be scaled. For this work, z-score scaling was used.</li>
		<li>Choose a blind source separation algorithm for the ICA. For this work, Infomax was used. GIFT offers a choice of at least 10 different algorithms.</li>
		<li>Remaining parameters can be left as is.</li>
	</ol>
	</li>
	<li>Once the ICA is completed, select from among available components those that are of potential theoretical interest. Through the GIFT GUI, choose component selection: spatial sorting sorts the spatial components by means of spatial correlation with a pre-existing template; temporal sorting sorts the component time courses by means of linear predictors from the SPM design matrix that you can store with the data (see 3.3.5). 
	Note: Both approaches to component selection have utility. However, when working with task data, temporal selection criteria are particularly useful, as they provide a means of verifying that the selected component was activated by the task. In the case of the DCCS, use of temporal sorting can be used to confirm that the selected component was more active during switch blocks than during repeat blocks.</li>
	<li>Test whether child and adult versions of these selected components differ. Aggregate child and adult components of interest into two separate groups and test by means of a two-sample t-test regions where the components vary. This is relatively easy to do through the GIFT GUI.</li>
</ol>

<ol>
	<li>Diamond, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Normal+Development+of+Prefrontal+Cortex+from+Birth+to+Young+Adulthood:+Cognitive+Functions+Anatomy,+and+Biochemistry.">Normal Development of Prefrontal Cortex from Birth to Young Adulthood: Cognitive Functions Anatomy, and Biochemistry.</a> Principles of Frontal Lobe Function. , 1-38 (2002).</li><li>Zelazo, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Dimensional+Change+Card+Sort+(DCCS):+a+method+of+assessing+executive+function+in+children.">The Dimensional Change Card Sort (DCCS): a method of assessing executive function in children.</a> Nat Protoc. 1, 297-301 (2006).</li><li>Monsell, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Task+switching.">Task switching.</a> Trends Cogn Sci (Regul Ed. 7, 134-140 (2003).</li><li>Crone, E. A., Bunge, S. A., van der Molen, M. W., Ridderinkhof, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switching+between+tasks+and+responses:+a+developmental+study.">Switching between tasks and responses: a developmental study.</a> Developmental Science. 9, 278-287 (2006).</li><li>Cole, M. W., Schneider, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cognitive+control+network:+Integrated+cortical+regions+with+dissociable+functions.">The cognitive control network: Integrated cortical regions with dissociable functions.</a> Neuroimage. 37, 343-360 (2007).</li><li>Fair, D. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+distinct+control+networks+through+segregation+and+integration.">Development of distinct control networks through segregation and integration.</a> Proc Natl Acad Sci USA. 104, 13507-13512 (2007).</li><li>Uddin, L. Q., Supekar, K., Menon, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Typical+and+atypical+development+of+functional+human+brain+networks:+insights+from+resting-state+FMRI.">Typical and atypical development of functional human brain networks: insights from resting-state FMRI.</a> Frontiers in systems neuroscience. 4, (2010).</li><li>Calhoun, V. D., Adali, T., Pearlson, G. D., Pekar, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+making+group+inferences+from+functional+MRI+data+using+independent+component+analysis.">A method for making group inferences from functional MRI data using independent component analysis.</a> Human brain mapping. 14, 140-151 (2001).</li><li>Fransson, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resting-state+networks+in+the+infant+brain.">Resting-state networks in the infant brain.</a> Proceedings of the National Academy of Sciences of the United States of America. 104, 15531-15536 (2007).</li><li>Supekar, K., Menon, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+maturation+of+dynamic+causal+control+signals+in+higher-order+cognition:+a+neurocognitive+network+model.">Developmental maturation of dynamic causal control signals in higher-order cognition: a neurocognitive network model.</a> PLoS computational biology. 8, (2012).</li><li>Power, J. D., Barnes, K. A., Snyder, A. Z., Schlaggar, B. L., Petersen, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spurious+but+systematic+correlations+in+functional+connectivity+MRI+networks+arise+from+subject+motion.">Spurious but systematic correlations in functional connectivity MRI networks arise from subject motion.</a> Neuroimage. 59, 2142-2154 (2012).</li><li>Raschle, N. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Making+MR+Imaging+Child's+Play+-+Pediatric+Neuroimaging+Protocol,+Guidelines+and+Procedure.">Making MR Imaging Child's Play - Pediatric Neuroimaging Protocol, Guidelines and Procedure.</a> (29), (2009).</li><li>Morton, J. B., Bosma, R., Ansari, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age-related+changes+in+brain+activation+associated+with+dimensional+shifts+of+attention:+an+fMRI+study.">Age-related changes in brain activation associated with dimensional shifts of attention: an fMRI study.</a> Neuroimage. 46, 249-256 (2009).</li><li>Ezekiel, F., Bosma, R., Morton, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dimensional+Change+Card+Sort+performance+associated+with+age-related+differences+in+functional+connectivity+of+lateral+prefrontal+cortex.">Dimensional Change Card Sort performance associated with age-related differences in functional connectivity of lateral prefrontal cortex.</a> Developmental Cognitive Neuroscience. , (2013).</li><li>Calhoun, V. D., Kiehl, K. A., Pearlson, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+temporally+coherent+brain+networks+estimated+using+ICA+at+rest+and+during+cognitive+tasks.">Modulation of temporally coherent brain networks estimated using ICA at rest and during cognitive tasks.</a> Human brain mapping. 29, 828-838 (2008).</li><li>Allen, E. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+baseline+for+the+multivariate+comparison+of+resting-state+networks.">A baseline for the multivariate comparison of resting-state networks.</a> Front Syst Neurosci. 5, (2011).</li><li>Calhoun, V. D., Liu, J., Adali, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+group+ICA+for+fMRI+data+and+ICA+for+joint+inference+of+imaging,+genetic,+and+ERP+data.">A review of group ICA for fMRI data and ICA for joint inference of imaging, genetic, and ERP data.</a> Neuroimage. 45, (2009).</li><li>Allen, E. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tracking+whole-brain+connectivity+dynamics+in+the+resting+state.">Tracking whole-brain connectivity dynamics in the resting state.</a> Cerebral Cortex. , (2012).</li></ol>

There are no competing financial interests.

Higher-order mental operations, such as the ability to switch sorting rules, develop rapidly throughout childhood and adolescence. Because these mental operations involve interactions between multiple distributed brain regions, there is growing interest in exploring the relationship between the development of higher-order cognition and age-related changes in the organization of broad-scale cortical networks. We present a method based on group independent component analysis applied to task-based fMRI data as a means of ex...

A capacidade de regular o comportamento se desenvolve gradualmente na infância e adolescência (para revisão, ver Diamond 1). Na Dimensional Ordenar tarefa Alterar Card, por exemplo, os participantes mudar de classificação cartões de uma maneira, como forma, para classificá-los de forma diferente, como a cor 2 (ver Figura 2). Switching cobra um custo de desempenho pequeno, ou custo switch, de tal forma que as respostas são geralmente mais lento e em ensaios de switch propenso a erros em que as mudanças de regras de classificação, em comparação a repetir os ensaios em que a regra de classificação continua a ser o mesmo 3. A magnitude destes custos normalmente fica menor quando as crianças crescem 4, ilustrando o fato de que a capacidade de regulação comportamental sofre desenvolvimento contínuo no início da vida. Como as operações mentais complexas, como comutação, envolvem interações rápidas entre várias regiões do cérebro 5, há um interesse crescente em relating do desenvolvimento da cognição de ordem superior a alterações na organização funcional de redes corticais larga escala 6. Uma abordagem para investigar mudanças de desenvolvimento em redes de grande escala é através do uso de-base de sementes funcional 6,7 análise de conectividade. O primeiro passo para essa técnica é consultar com literatura de pesquisa disponível e definir um a priori regiões de interesse, ou ROI, que parecem ser relevantes para o comportamento em questão. Estes ROI, ou nodos, definem o esqueleto de base da rede. Em seguida, as flutuações de baixa frequência em atividade (ou T2 * ponderada intensidade do sinal) nestes ROIs são medidos por 5 a 10 minutos, enquanto os participantes estão em repouso em um scanner de ressonância magnética. Conectividade funcional entre dois nós da rede é então quantificada como a correlação de seus respectivos cursos de tempo. Nós que estão fortemente ligadas funcionalmente deve ter semelhante e, portanto, altamente correlacionados, sinalcursos de tempo. Por outro lado, os nós que são fracamente ligados funcionalmente deve ter diferentes e, assim, fracamente correlacionadas, sinalizar cursos de tempo. Para completar um modelo de rede, extremidades (ou ligações) são desenhadas entre os nós cujos cursos de tempo correlacionar acima de um limite escolhido. Os testes de diferenças relacionadas à idade na conectividade funcional dentro de uma rede pode ser realizada em qualquer conexão único nó a nó, ou na topologia de todo o conjunto de nós e arestas. Essas diferenças de conectividade funcional pode estar relacionado com as medidas de desempenho cognitivo coletadas offline. Neste trabalho, uma abordagem diferente é descrito que é baseado no grupo de análise de componentes independentes dos dados 8 fMRI baseados em tarefas. Análise de componentes independentes (ou ICA) é um procedimento estatístico para cegamente revelando fontes ocultas subjacentes a um conjunto de observações de tal forma que as fontes reveladas são maximamente independente. Aplicado à análise de dados de fMRI, o pROCEDIMENTO assume que cada volume é uma mistura de um número finito de fontes espacialmente independentes. Usando um de uma variedade de diferentes algoritmos, como o algoritmo Infomax, ICA, em seguida, calcula uma matriz de desmistura, que quando aplicadas aos dados originais produz um conjunto de fontes independentes, ou maximamente componentes. Cada componente pode ser pensado como uma rede, na medida em que é composta por um conjunto de voxeis que partilham um curso de tempo comum. Grupo ICA é um tipo particular de ICA em que um conjunto comum de componentes do grupo é estimado a partir de um primeiro conjunto de dados inteiro, e, em seguida, conjuntos de componentes de grupos específicos de participantes são computados em um passo para trás-reconstrução. Uma vez que um conjunto de dados inteiro é decomposto em um conjunto de componentes, o próximo passo é descartar componentes de artefatos que representam fontes de ruído e identificar componentes teoricamente significativos que correspondem com as redes de interesse. Isto pode ser conseguido quer por meio de cursos de tempo dos componentes de modelagem, no contexto de um GLM identify redes que activam de um modo previsível, correlacionando espacialmente os componentes com um modelo de rede de interesse, ou de ambos. O conjunto resultante de componentes podem então ser submetido a uma comparação entre os grupos para testar possíveis diferenças relacionadas à idade na conectividade funcional dentro das redes, teoricamente interessantes 7,9,10. Dados fMRI baseados em tarefas Estudar mudanças relacionadas à idade na conectividade funcional através da aplicação de grupo ICA para tem várias vantagens sobre a aplicação de técnicas baseadas em sementes de dados de fMRI descansando estatais. Em primeiro lugar, ao contrário de técnicas baseadas em sementes que se concentram em um pequeno conjunto de ROIs definidas a priori, a abordagem do grupo ICA atual utiliza todos os voxels que compreendem uma série de tempo volumétrica. Isso diminui as oportunidades de viés que necessariamente surgem quando um pequeno grupo de sementes são selecionados a priori como regiões de interesse. Em segundo lugar, a aplicação da análise de conectividade funcional (baseado em ICA ou não) a tarefaao invés de dados fMRI descansando-estado tem a vantagem de permitir a organização da rede ea função de rede a ser associada mais diretamente. Se, por exemplo, examinando as implicações cognitivas ou comportamentais da conectividade funcional (tal como a variação no desempenho DCCS) é uma prioridade, é importante demonstrar que a rede de interesse está associado com o desempenho da tarefa. Com os protocolos de repouso pelo Estado, isto é muito difícil, porque o pesquisador não tem registro de nenhum estados cognitivos, comportamentais ou afetivos experimentados pelo participante durante a aquisição de dados. Por isso, é impossível fornecer a evidência direta de que qualquer rede de juros é relevante para o desempenho da tarefa. Em contraste, quando a análise de conectividade funcional, tal como ACI, é aplicada a tarefa de dados, é possível confirmar que a rede de interesse é, pelo menos, está relacionado com o desempenho de uma tarefa. Finalmente, o ICA é menos sujeito à influência adversa de ruído. Fontes de ruído, como os sagacidade associadoh assunto de movimento e ritmo cardíaco, têm perfis de espaço-temporais únicas. Portanto, no contexto de um grupo de ACI, estas fontes são isoladas e caracterizadas de componentes separados, deixando restantes componentes relativamente livre destas fontes indesejáveis ​​da variância. Vez que as análises baseadas em sementes usar cursos de tempo bruto na estimativa da conectividade funcional, e cursos de tempo são, por definição, as misturas de sinal neurofisiológico e ruído artifactual, as diferenças nas estimativas do grupo de conectividade funcional podem refletir diferenças entre os grupos verdadeiros em neurofisiologia subjacente, as diferenças de grupo em a estrutura de ruído, ou ambos 11.

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a method for investigating age-related differences in the functional connectivity of cognitive control networks associated with dimensional change card sort performance

A capacidade de ajustar o comportamento a mudanças bruscas no ambiente desenvolve-se gradualmente na infância e adolescência. Por exemplo, na Dimensional Ordenar tarefa Alterar Card, participantes mudar de classificação cartões de uma forma, como a forma, a classificá-los de forma diferente, como a cor. Ajustar o comportamento dessa forma exige um custo de desempenho pequeno, ou custo switch, de tal forma que as respostas são geralmente mais lento e em ensaios de switch propenso a erros em que as mudanças de regras de classificação, em comparação a repetir os ensaios em que a regra de classificação continua a mesma. A capacidade de ajustar de forma flexível comportamento muitas vezes é dito, de forma gradual, em parte porque os custos de comportamento, tais como custos de comutação normalmente diminuem com o aumento da idade. Por aspectos da cognição de ordem superior, como a flexibilidade comportamental, desenvolver de forma gradual continua a ser uma questão em aberto. Uma hipótese é que essas mudanças ocorrem em associação com alterações funcionais em redes de controle cognitivo ampla escala. Deste ponto de vista,operações mentais complexas, como comutação, envolvem interações rápidas entre várias regiões do cérebro distribuídos, incluindo aqueles que atualizar e manter as regras da tarefa, atenção reorientar e selecione comportamentos. Com o desenvolvimento, as conexões funcionais entre essas regiões fortalecer, levando a operações de comutação mais rápidos e eficazes. O vídeo atual descreve um método de testar esta hipótese, através da recolha e análise multivariada de dados de fMRI de participantes de diferentes idades.

Group ICA, even on a relatively small fMRI data set, will return a set of components comparable to those observed in other studies. Figure 4&#160;is a superimposition of 5 such components and their associated time courses unmixed from a sample of 12 children and 13 adults, with approximately 800 volumes per participant. As shown in Figure 4, default mode, fronto-parietal, cingulo-insular, and visual networks can readily be seen from the results of this decomposition. As well, notice how ...

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A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance

This video presents a method of examining age-related changes in functional connectivity of cognitive control networks engaged by targeted tasks/processes. The technique is based on multi-variate analysis of fMRI data.

Um método para investigar diferenças relacionadas à idade na conectividade funcional of Cognitive Controle Networks associados à mudança Dimensional Card Sort Desempenho

The ability to adjust behavior to sudden changes in the environment develops gradually in childhood and adolescence. For example, in the Dimensional ...

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10.1K visualizações.  University of Western Ontario. This video presents a method of examining age-related changes in functional connectivity of cognitive control networks engaged by targeted tasks/processes. The technique is based on multi-variate analysis of fMRI data.

Vídeo: A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance

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.

A Task Congruência Crossmodal como um meio para se obter uma medida comportamental Objetivo no Rubber Mão 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 ...

Comportamento

Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this transformation. Here we discuss a novel method for simulating the appearance of an object that has undergone a rotation-in-depth, and include an exposition of the differences between perspective and orthographic projections. Next we describe a method by which human sensitivity to rotation-in-depth can be measured. Finally we discuss an apparatus for creating a vivid percept of a 3-dimensional rotation-in-depth; the Wheatstone Eight Mirror Stereoscope. By doing so, we reveal a means by which to evaluate the role of stereoscopic cues in the discrimination of viewpoint rotated shapes and objects.

We discuss a novel method forviewpoint-rotation of visual stimuli, and demonstrate using a mirror stereoscopethe three-dimensional percept of rotation-in-depth. The technique can be used to investigate the role of stereoscopic cues in encoding viewpoint-rotated figures.

Medição Sensibilidade à Mudança Viewpoint com e sem Stereoscopic Sugestões

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this ...

Assessment of Age-related Changes in Cognitive Functions Using EmoCogMeter, a Novel Tablet-computer Based Approach

The main goal of this study was to assess the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognitive functions across the lifespan in a sample of 378 healthy subjects (age range 18-89 years). Consistent with previous findings we found an age-related cognitive decline across a wide range of neuropsychological domains (memory, attention, executive functions), thereby proving the usability of our tablet-based application. Regardless of prior computer experience, subjects of all age groups were able to perform the tasks without instruction or feedback from an experimenter. Increased motivation and compliance proved to be beneficial for task performance, thereby potentially increasing the validity of the results. Our promising findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction.

We tested the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognition. Results show an age-related cognitive decline, thereby proving the usability of our application. Findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction.

Avaliação das Alterações relacionadas à idade em Funções Cognitivas Usando EmoCogMeter, uma nova abordagem Tablet computador baseado

The main goal of this study was to assess the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on ...

A Fully Automated Rodent Conditioning Protocol for Sensorimotor Integration and Cognitive Control Experiments

Rodents have been traditionally used as a standard animal model in laboratory experiments involving a myriad of sensory, cognitive, and motor tasks. Higher cognitive functions that require precise control over sensorimotor responses such as decision-making and attentional modulation, however, are typically assessed in nonhuman primates. Despite the richness of primate behavior that allows multiple variants of these functions to be studied, the rodent model remains an attractive, cost-effective alternative to primate models. Furthermore, the ability to fully automate operant conditioning in rodents adds unique advantages over the labor intensive training of nonhuman primates while studying a broad range of these complex functions.
Here, we introduce a protocol for operantly conditioning rats on performing working memory tasks. During critical epochs of the task, the protocol ensures that the animal's overt movement is minimized by requiring the animal to 'fixate' until a Go cue is delivered, akin to nonhuman primate experimental design. A simple two alternative forced choice task is implemented to demonstrate the performance. We discuss the application of this paradigm to other tasks.

A fully automated protocol for rodent operant conditioning is proposed. The protocol relies on precise temporal control of behavioral events to investigate the extent to which this control influences neural activity underlying sensorimotor integration and cognitive control experiments.

Um totalmente automatizada Roedor Condicionado Protocolo para Sensorimotor Integração e Experimentos controle cognitivo

Rodents have been traditionally used as a standard animal model in laboratory experiments involving a myriad of sensory, cognitive, and motor tasks. ...

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.

Avaliação do Desempenho Funcional no<em&gt; Mdx</em&gt; Mouse Modelo

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

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.

Combinadas Funções Invasiva subcorticais e Superfície Non-invasive neurofisiológica Gravações de Avaliação da cognitivos e emocionais em humanos

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

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.

O emocional Stroop Task: Avaliação de Desempenho Cognitivo sob exposição a conteúdo emocional

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 ...

A Pressure Injection System for Investigating the Neuropharmacology of Information Processing in Awake Behaving Macaque Monkey Cortex

The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation of sensory information processing by attention. However, little is known about which neurotransmitter systems are involved in such modulations. A practical way to address this question is to combine single-cell recording with local and temporary neuropharmacological manipulation in a suitable animal model. Here we demonstrate a technique combining acute single-cell recordings with the injection of neuropharmacological agents in the direct vicinity of the recording electrode. The video shows the preparation of the pressure injection/recording system, including preparation of the substance to be injected. We show a rhesus monkey performing a visual attention task and the procedure of single-unit recording with block-wise pharmacological manipulations.

Here, we show the pressure injection of neuropharmacological substances during single-cell recording in an awake, behaving macaque monkey. This procedure allows pharmacological manipulation in the direct vicinity of a cortical recording site.

Um sistema de injeção de pressão para a investigação da neurofarmacologia de Processamento de Informação em Despertai Behaving Macaque Cortex

The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation ...

The Rodent Psychomotor Vigilance Test (rPVT): A Method for Assessing Neurobehavioral Performance in Rats and Mice

The human Psychomotor Vigilance Test (PVT) is a widely used procedure for measuring changes in fatigue and sustained attention. The present article describes a rodent version of the PVT&#8212;termed the &#34;rPVT&#34;&#8212;that measures similar aspects of attention (i.e., performance accuracy, motor speed, premature responding, and lapses in attention). Data are presented that demonstrate both the short- and long-term usefulness of the rPVT when employed with laboratory rats. Rats easily learn the rPVT, and learning to perform the basic procedure takes less than two weeks of training. Once acquired, rat performances in the rPVT show a high degree of similarity to these same performance measures in the human PVT, including similarities in, lapses in attention, reaction times, vigilance decrements across session time (i.e., the human &#34;time-on-task&#34; effects), and the response-stimulus interval (RSI) effect described for humans. Thus the rPVT can be an extremely valuable tool for assessing the effects of a wide range of variables on sustained attention quite similar to human PVT performances, and thus can be useful for developing novel treatments for neurobehavioral dysfunctions.

The Rodent Psychomotor Vigilance Test rPVT: A Method for Assessing Neurobehavioral Performance in Rats and Mice

A rat version of the human Psychomotor Vigilance Test (PVT) is described that measures aspects of attention similar to those measured with the human PVT, including aspects of human vigilance such as performance accuracy, motor speed, premature responding, and lapses in attention.

O psicomotora Teste Rodent Vigilância (rPVT): um método para avaliar Neurobehavioral Desempenho em ratos e camundongos

The human Psychomotor Vigilance Test (PVT) is a widely used procedure for measuring changes in fatigue and sustained attention. The present article ...

Eye-Tracking Control to Assess Cognitive Functions in Patients with Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to progressive loss of motor and speech abilities. In addition, cognitive functions are impaired in a subset of patients. To evaluate these potential deficits in severely physically impaired ALS patients, eye-tracking is a promising means to conduct cognitive tests. The present article focuses on how eye movements, an indirect means of communication for physically disabled patients, can be utilized to allow for detailed neuropsychological assessment. The requirements, in terms of oculomotor parameters that have to be met for sufficient eye-tracking in ALS patients are presented. The properties of stimuli, including type of neuropsychological tests and style of presentation, best suited to successfully assess cognitive functioning, are also described. Furthermore, recommendations regarding procedural requirements are provided. Overall, this methodology provides a reliable, easy to administer and fast approach for assessing cognitive deficits in patients who are unable to speak or write such as patients with severe ALS. The only confounding factor might be deficits in voluntary eye movement control in a subset of ALS patients.

Cognitive deficits are common in about one third of patients with amyotrophic lateral sclerosis, a neurological condition leading to progressive impairments in speech and movement abilities. To conduct cognitive tests in patients unable to speak or write a reliable and easy to administer eye-tracking paradigm was developed.

Eye-Tracking de controle para avaliar a função cognitiva em pacientes com Esclerose Lateral Amiotrófica

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to ...