Os autores reconhecem o apoio financeiro do Conselho de Pesquisa em Ciências Sociais e Humanas do Canadá (SSHERC).

<ol>
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W., Schwebel, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distracted+walking:+Cell+phones+increase+injury+risk+for+college+pedestrians.">Distracted walking: Cell phones increase injury risk for college pedestrians.</a> Journal of Safety Research. 42 (2), 101-107 (2011).</li><li>Nasar, J., Hecht, P., Wener, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mobile+telephones,+distracted+attention,+and+pedestrian+safety.">Mobile telephones, distracted attention, and pedestrian safety.</a> Accident Analysis, Prevention. 40 (1), 69-75 (2008).</li><li>Hyman, I. E., Boss, S. M., Wise, B. M., McKenzie, K. E., Caggiano, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Did+you+see+the+unicycling+clown?+Inattentional+blindness+while+walking+and+talking+on+a+cell+phone.">Did you see the unicycling clown? Inattentional blindness while walking and talking on a cell phone.</a> Applied Cognitive Psychology. 24 (5), 597-607 (2010).</li><li>Pourchon, R., 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=Is+augmented+reality+leading+to+more+risky+behaviors?+An+experiment+with+pok&#233;mon+go.">Is augmented reality leading to more risky behaviors? An experiment with pok&#233;mon go.</a> Proceedings of the International Conference on HCI in Business, Government, and Organizations. , 354-361 (2017).</li><li>Thornton, I. M., Rensink, R. A., Shiffrar, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Active+versus+Passive+Processing+of+Biological+Motion.">Active versus Passive Processing of Biological Motion.</a> Perception. 31 (7), 837-853 (2002).</li><li>Neider, M. B., McCarley, J. S., Crowell, J. A., Kaczmarski, H., Kramer, A. 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T., Thornton, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Attention-based+visual+routines:+Sprites.">Attention-based visual routines: Sprites.</a> Cognition. 80 (1-2), 47-60 (2001).</li><li>Troje, N. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retrieving+Information+from+Human+Movement+Patterns.">Retrieving Information from Human Movement Patterns.</a> Understanding Events. , 308-334 (2008).</li><li>Klimesch, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EEG+alpha+and+theta+oscillations+reflect+cognitive+and+memory+performance:+A+review+and+analysis.">EEG alpha and theta oscillations reflect cognitive and memory performance: A review and analysis.</a> Brain Research Reviews. 29 (2-3), 169-195 (1999).</li><li>Jensen, O., Gelfand, J., Kounios, J., Lisman, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oscillations+in+the+Alpha+Band+(9-12+Hz)+Increase+with+Memory+Load+during+Retention+in+a+Short-term+Memory+Task.">Oscillations in the Alpha Band (9-12 Hz) Increase with Memory Load during Retention in a Short-term Memory Task.</a> Cerebral Cortex. 12 (8), 877-882 (2002).</li><li>Busch, N. A., Herrmann, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Object-load+and+feature-load+modulate+EEG+in+a+short-term+memory+task.">Object-load and feature-load modulate EEG in a short-term memory task.</a> NeuroReport. 14 (13), 1721-1724 (2003).</li><li>Herrmann, C. S., Senkowski, D., R&#246;ttger, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phase-Locking+and+Amplitude+Modulations+of+EEG+Alpha.">Phase-Locking and Amplitude Modulations of EEG Alpha.</a> Experimental Psychology. 51 (4), 311-318 (2004).</li><li>Pfurtscheller, G., Aranibar, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Event-related+cortical+desynchronization+detected+by+power+measurements+of+scalp+EEG.">Event-related cortical desynchronization detected by power measurements of scalp EEG.</a> Electroencephalography and Clinical Neurophysiology. 42 (6), 817-826 (1977).</li><li>Sauseng, 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=EEG+alpha+synchronization+and+functional+coupling+during+top-down+processing+in+a+working+memory+task.">EEG alpha synchronization and functional coupling during top-down processing in a working memory task.</a> Human Brain Mapping. 26 (2), 148-155 (2005).</li><li>Pope, A. T., Bogart, E. H., Bartolome, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biocybernetic+system+evaluates+indices+of+operator+engagement+in+automated+task.">Biocybernetic system evaluates indices of operator engagement in automated task.</a> Biological Psychology. 40 (1-2), 187-195 (1995).</li><li>Scerbo, M. W., Freeman, F. G., Mikulka, P. 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H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tests+for+comparing+elements+of+a+correlation+matrix.">Tests for comparing elements of a correlation matrix.</a> Psychological Bulletin. 87 (2), 245-251 (1980).</li><li>L&#233;ger, P. -. M., Davis, F., Riedl, R., vom Brocke, J., L&#233;ger, P. -. M., Randolph, A., Fischer, T. H., 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=Task+Switching+and+Visual+Discrimination+in+Pedestrian+Mobile+Multitasking:+Influence+of+IT+Mobile+Task+Type.">Task Switching and Visual Discrimination in Pedestrian Mobile Multitasking: Influence of IT Mobile Task Type.</a> Information Systems and Neuroscience: Vienna Retreat on NeuroIs 2019. , 245-251 (2020).</li><li>Mourra, G. 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Os autores não têm nada a revelar.

Uma escolha crítica ao usar o protocolo seria garantir a qualidade dos dados neurofisiológicos. Há uma complicação inerente ao uso de uma ferramenta como o EEG durante o movimento, porque o movimento excessivo pode criar muito ruído nos dados. Portanto, é importante considerar, antes da coleta de dados, como os dados serão preparados para remover o maior número possível de artefatos sem modificar o sinal real. No entanto, ainda é bastante provável que haja taxas mais altas de exclusão de dados porque os part...

An erratum was issued for:&#160;<a href="https://www.jove.com/t/60555/measuring-the-switch-cost-of-smartphone-use-while-walking">Measuring the Switch Cost of Smartphone Use While Walking</a>. An&#160;author&#39;s name&#160;was&#160;updated.
The name was corrected from:
Gabrielle-Na&#239;m&#233; Mourra
to:
Gabrielle Na&#239;m&#233; Mourra

An erratum was issued for:&#160;<a href="https://www.jove.com/t/60555/measuring-the-switch-cost-of-smartphone-use-while-walking">Measuring the Switch Cost of Smartphone Use While Walking</a>. An&#160;author&#39;s name&#160;was&#160;updated.

Erratum: Measuring the Switch Cost of Smartphone Use While Walking

Como tanto a penetração do smartphone quanto a tendência à multitarefa estão aumentando, é importante entender o impacto que o uso do smartphone ao caminhar tem na atenção. A literatura demonstrou repetidamente que a troca de tarefas vem com um custo1, incluindo o uso de smartphones durante a caminhada. Estudos descobriram que o uso de um smartphone durante a caminhada pode ser perturbador e perigoso 2,3,4. Esses perigos têm sido associados aos prejuízos de atenção de realizar tal tarefa 3,4,5,6,7. Devido à natureza complexa do ambiente pedestre, estudá-lo em um contexto experimental ecologicamente válido pode ser problemático. No entanto, a realização de tais estudos em ambientes pedestres reais pode vir com complicações próprias, porque muitas variáveis estranhas podem entrar em jogo, e há um risco de danos ao participante devido a distrações. É importante ser capaz de estudar tal fenômeno em um ambiente relativamente seguro que permaneça o mais realista possível. Neste artigo, descrevemos uma metodologia de pesquisa que estuda o custo de troca de tarefas de mensagens de texto durante a caminhada, aumentando a validade da tarefa e mitigando os riscos potenciais envolvidos.
Ao usar um smartphone enquanto caminha, os indivíduos são forçados a mudar das tarefas do smartphone para tarefas de caminhada e relacionadas ao meio ambiente. Assim, para estudar tal fenômeno, achamos pertinente enquadrar esse método na literatura sobre multitarefa, especificamente focada no paradigma da troca de tarefas. Para isso, utilizou-se o paradigma de troca de tarefas1, fazendo com que os participantes alternassem entre uma tarefa pré-estímulo e uma tarefa pós-estímulo. Uma das duas tarefas pré-estímulo envolvia multitarefa, enquanto a outra não. Na tarefa pós-estímulo, os participantes tiveram que responder a um estímulo cuja percepção é influenciada pela atenção dividida8. Além disso, estudos experimentais de laboratório que tentam ser o mais ecologicamente válidos possível têm frequentemente utilizado ambientes virtuais de pedestres para entender o impacto atencional do uso de smartphones durante a caminhada 4,9. No entanto, a fim de capturar os mecanismos neurofisiológicos subjacentes, optamos por nos concentrar na reação específica de troca de tarefas a um estímulo para minimizar o número de estímulos aos quais os participantes tiveram que reagir. Desta forma, podemos identificar com mais precisão o custo de troca de tarefas proveniente puramente da mudança de atenção para longe do smartphone e para o estímulo. Com o desenho do nosso estudo, usamos medidas comportamentais (ou seja, custo de troca de tarefas) e dados neurofisiológicos para entender melhor os prejuízos de atenção encontrados durante o uso de smartphones para pedestres.
Durante um experimento de troca de tarefas, os participantes geralmente realizavam pelo menos duas tarefas simples pertencentes a um conjunto de estímulos, com cada tarefa exigindo um conjunto diferente de recursos cognitivos referidos como um "conjunto de tarefas"1. Quando os indivíduos são forçados a alternar entre tarefas, seus recursos mentais precisam se adaptar (ou seja, inibição do conjunto de tarefas anteriores e ativação do conjunto de tarefas atual). Acredita-se que esse processo de "reconfiguração do conjunto de tarefas" seja a causa do custo de alternância de tarefas1. O custo de troca de tarefas é geralmente determinado observando as diferenças no tempo de resposta e / ou na taxa de erro entre as tentativas em que os participantes alternam entre tarefas e aquelas em que não alternam10. Em nosso experimento, tivemos três conjuntos de tarefas: 1) responder a um estímulo de andador pontual-leve; 2) mensagens de texto em um smartphone enquanto caminha; e 3) simplesmente caminhar. Comparamos o custo da troca entre duas condições diferentes: 1) simplesmente andar antes de responder ao estímulo e 2) andar enquanto enviava mensagens de texto antes de responder. Dessa forma, capturamos o custo da multitarefa em um smartphone antes de alternar a tarefa e fomos capazes de compará-lo diretamente com o custo do interruptor não multitarefa de simplesmente caminhar antes do aparecimento do estímulo visual. Como o smartphone usado neste estudo era de uma marca específica, todos os participantes foram examinados antes do experimento para ter certeza de que sabiam como usar corretamente o dispositivo.
Para simular uma experiência realista representativa do contexto do pedestre, optou-se por utilizar uma figura de caminhante ponto-luz como estímulo visual, representando uma forma humana caminhando com um ângulo de desvio de 3,5° para a esquerda ou para a direita do participante. Essa figura é composta por 15 pontos pretos sobre fundo branco, com os pontos representando a cabeça, ombros, quadris, cotovelos, punhos, joelhos e tornozelos de um ser humano (Figura 1). Esse estímulo é baseado no movimento biológico, o que significa que segue o padrão de movimento típico de humanos e animais11. Além disso, esse estímulo é mais do que ecologicamente válido; requer processamento visual complexo e atenção para ser analisada com sucesso12,13. Curiosamente, Thornton et al.8 descobriram que a identificação adequada da direção do andador em forma de ponto é muito impactada pela atenção dividida, tornando-a adequada como uma medida de desempenho ao estudar os custos de troca de tarefas ao multitarefa. Os participantes foram convidados a declarar verbalmente a direção em que a figura estava andando. A aparência do andador era sempre precedida por uma sugestão auditiva que sinalizava sua aparência na tela.
O desempenho na tarefa de andador ponto-luz e os dados neurofisiológicos nos permitiram determinar o impacto atencional de ambas as condições e ajudar a determinar o que as causou. O desempenho foi medido observando as taxas de erro e os tempos de resposta ao determinar a direção da figura do andador ponto-luz. A fim de compreender os mecanismos cognitivos e atencionais subjacentes envolvidos nos comprometimentos de atenção que encontramos com a medida de desempenho, avaliamos os dados neurofisiológicos dos participantes usando o EEG actiCAP com 32 eletrodos. O EEG é uma ferramenta apropriada em termos de precisão temporária, o que é importante ao tentar ver o que causa um desempenho ruim em momentos específicos no tempo (por exemplo, a aparência da figura do andador com luz pontual), embora artefatos possam estar presentes nos dados devido a movimentos. Ao analisar os dados do EEG, dois índices são particularmente relevantes: 1) oscilações alfa; e 2) engajamento cognitivo. Pesquisas descobriram que as oscilações alfa podem representar o controle da memória de trabalho, bem como a inibição ativa de circuitos cerebrais irrelevantes para a tarefa14,15,16,17. Comparando-se as oscilações alfa nos níveis basais com as que ocorrem com a apresentação do estímulo 18,19, obteve-se a razão alfa. Com essa proporção, determinamos as mudanças relacionadas ao evento que poderiam estar subjacentes ao comprometimento da atenção observado ao enviar mensagens de texto durante a caminhada. Com relação ao engajamento cognitivo, Pope et al.20 desenvolveram um índice em que a atividade beta representa aumento da excitação e da atenção, e a atividade alfa e refletem diminuições na excitação e atenção21,22. Esta análise foi feita para determinar se o aumento do engajamento antes do aparecimento do estímulo complicaria a reconfiguração do conjunto de tarefas necessária para responder à figura do andador.
Com a metodologia descrita neste artigo, buscamos apreender os mecanismos subjacentes que afetam o desempenho da troca de tarefas em participantes envolvidos em episódios multitarefas. A condição de andar representa um desempenho de alternador de tarefas não multitarefa que é comparado a um desempenho de comutador de tarefa multitarefa (ou seja, mensagens de texto durante a caminhada). Ao medir os papéis da inibição do conjunto de tarefas e da ativação do conjunto de tarefas, procuramos entender melhor os custos de troca que ocorrem ao enviar mensagens de texto durante a caminhada. É relevante notar que o estudo original foi realizado em um ambiente virtual imersivo23 , mas posteriormente replicado em uma sala experimental (ver Figura 2) com um projetor exibindo a figura do andador em uma tela na frente do participante. Como esse ambiente virtual não está mais disponível, o protocolo foi adaptado ao desenho atual da sala experimental.

<table border="0" cellpadding="0" cellspacing="0" style="width:1068px;" width="1068">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">The Observer XT</td>
			<td style="width:292px;">Noldus</td>
			<td style="width:83px;"></td>
			<td style="width:477px;">Integration and synchronization software: The Noldus Observer XT (Noldus Information Technology) is used to synchronize all behavioral, emotional and cognitive engagement data.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">MediaRecorder</td>
			<td style="width:292px;">Noldus</td>
			<td style="width:83px;"></td>
			<td>Audio and video recording software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">FaceReader</td>
			<td style="width:292px;">Noldus</td>
			<td style="width:83px;"></td>
			<td>Software for automatic analysis of the 6 basic facial expressions</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">E-Prime</td>
			<td style="width:292px;">Psychology Software Tools, Inc.</td>
			<td style="width:83px;"></td>
			<td>Software for computerized experiment design, data collection, and analysis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">BrainVision Recorder</td>
			<td style="width:292px;">Brain Vision</td>
			<td style="width:83px;"></td>
			<td>Software used for recording neuro-/electrophysiological signals (EEG in this case)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Analyzer</td>
			<td style="width:292px;"></td>
			<td style="width:83px;"></td>
			<td>EEG signal processing software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Qualtrics</td>
			<td style="width:292px;">Qualtrics</td>
			<td style="width:83px;"></td>
			<td>Online survey environment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tapis Roulant</td>
			<td style="width:292px;">ThermoTread GT Office Treadmill</td>
			<td style="width:83px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Syncbox</td>
			<td style="width:292px;">Noldus</td>
			<td style="width:83px;"></td>
			<td>Syncbox start the co-registration of EEG and gaze data by sending a Transistor-Transistor Logic (TTL) signal to the EGI amplifier and a keystroke signal to the Tobii Studio v 3.2.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Move2actiCAP</td>
			<td style="width:292px;">Brain Vision</td>
			<td style="width:83px;"></td>
			<td>Add-on for a digital wireless system for EEG</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">iPhone 6s</td>
			<td style="width:292px;">Apple</td>
			<td style="width:83px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">iMessage</td>
			<td style="width:292px;">Apple</td>
			<td style="width:83px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">iPad</td>
			<td style="width:292px;">Apple</td>
			<td style="width:83px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

measuring the switch cost of smartphone use while walking

Este artigo apresenta um protocolo de estudo para medir o custo de troca de tarefas do uso de um smartphone durante a caminhada. Este método envolve fazer com que os participantes andem em uma esteira sob duas condições experimentais: uma condição de controle (ou seja, simplesmente caminhar) e uma condição multitarefa (ou seja, mensagens de texto enquanto caminha). Durante essas condições, os participantes devem alternar entre as tarefas relacionadas à condição experimental e uma tarefa determinante de direção. Esta tarefa de direção é feita com uma figura de caminhante de luz pontual, aparentemente caminhando para a esquerda ou para a direita do participante. O desempenho na tarefa de direção representa os custos de alternância de tarefas do participante. Houve duas medidas de desempenho: 1) identificação correta da direção e 2) tempo de resposta. Os dados de EEG são registrados para medir as oscilações alfa e o engajamento cognitivo que ocorrem durante a troca de tarefas. Este método é limitado em sua validade ecológica: ambientes de pedestres têm muitos estímulos ocorrendo simultaneamente e competindo por atenção. No entanto, esse método é apropriado para identificar os custos de alternância de tarefas. Os dados de EEG permitem o estudo dos mecanismos subjacentes no cérebro que estão relacionados a diferentes custos de troca de tarefas. Este design permite a comparação entre a troca de tarefas ao fazer uma tarefa de cada vez, em comparação com a troca de tarefas ao multitarefa, antes da apresentação do estímulo. Isso permite entender e identificar o impacto comportamental e neurofisiológico dessas duas condições diferentes de troca de tarefas. Além disso, correlacionando os custos de troca de tarefas com a atividade cerebral, podemos aprender mais sobre o que causa esses efeitos comportamentais. Este protocolo é uma base apropriada para estudar o custo de comutação de diferentes usos de smartphones. Diferentes tarefas, questionários e outras medidas podem ser adicionadas a ele para entender os diferentes fatores envolvidos no custo de troca de tarefas do uso do smartphone durante a caminhada.

Este protocolo de estudo foi originalmente conduzido com 54 participantes, cada um respondendo a 88 ensaios de direção. Metade desses ensaios ocorreu quando os participantes estavam simplesmente andando antes da apresentação do estímulo; a outra metade ocorreu quando os participantes estavam enviando mensagens de texto enquanto caminhavam antes da apresentação do estímulo.
Resultados comportamentais O desempenho na direção do andador de luz pontual representa cust...

Watch this Scientific Journal Video about Measuring the Switch Cost of Smartphone Use While Walking at JoVE.com

Measuring the Switch Cost of Smartphone Use While Walking

Este projeto de estudo mede o custo de troca de tarefas do uso de um smartphone enquanto caminha. Os participantes são submetidos a duas condições experimentais: uma condição de controle (caminhada) e uma condição multitarefa (mensagens de texto durante a caminhada). Os participantes alternam entre essas tarefas e uma tarefa que determina a direção. Dados de EEG, bem como medidas comportamentais são registrados.

Medindo o custo do interruptor do uso do smartphone durante a caminhada

This paper presents a study protocol to measure the task-switching cost of using a smartphone while walking. This method involves having participants walk ...

measuring-the-switch-cost-of-smartphone-use-while-walking

Research

JoVE Journal

Behavior

1.7K visualizações.  HEC Montréal. Este projeto de estudo mede o custo de troca de tarefas do uso de um smartphone enquanto caminha. Os participantes são submetidos a duas condições experimentais: uma condição de controle (caminhada) e uma condição multitarefa (mensagens de texto durante a caminhada). Os participantes alternam entre essas tarefas e uma tarefa que determina a direção. Dados de EEG, bem como medidas comportamentais são registrados.

Vídeo: Measuring the Switch Cost of Smartphone Use While Walking

Evaluation of a Smartphone-based Human Activity Recognition System in a Daily Living Environment

An evaluation method that includes continuous activities in a daily-living environment was developed for Wearable Mobility Monitoring Systems (WMMS) that attempt to recognize user activities. Participants performed a pre-determined set of daily living actions within a continuous test circuit that included mobility activities (walking, standing, sitting, lying, ascending/descending stairs), daily living tasks (combing hair, brushing teeth, preparing food, eating, washing dishes), and subtle environment changes (opening doors, using an elevator, walking on inclines, traversing staircase landings, walking outdoors). 
To evaluate WMMS performance on this circuit, fifteen able-bodied participants completed the tasks while wearing a smartphone at their right front pelvis. The WMMS application used smartphone accelerometer and gyroscope signals to classify activity states. A gold standard comparison data set was created by video-recording each trial and manually logging activity onset times. Gold standard and WMMS data were analyzed offline. Three classification sets were calculated for each circuit: (i) mobility or immobility, ii) sit, stand, lie, or walking, and (iii) sit, stand, lie, walking, climbing stairs, or small standing movement. Sensitivities, specificities, and F-Scores for activity categorization and changes-of-state were calculated.
The mobile versus immobile classification set had a sensitivity of 86.30% &#177; 7.2% and specificity of 98.96% &#177; 0.6%, while the second prediction set had a sensitivity of 88.35% &#177; 7.80% and specificity of 98.51% &#177; 0.62%. For the third classification set, sensitivity was 84.92% &#177; 6.38% and specificity was 98.17 &#177; 0.62. F1 scores for the first, second and third classification sets were 86.17 &#177; 6.3, 80.19 &#177; 6.36, and 78.42 &#177; 5.96, respectively. This demonstrates that WMMS performance depends on the evaluation protocol in addition to the algorithms. The demonstrated protocol can be used and tailored for evaluating human activity recognition systems in rehabilitation medicine where mobility monitoring may be beneficial in clinical decision-making.

A standardized evaluation method was developed for Wearable Mobility Monitoring Systems (WMMS) that includes continuous activities in a realistic daily living environment. Testing with a series of daily living activities can decrease activity recognition sensitivity; therefore, realistic testing circuits are encouraged for valid evaluation of WMMS performance.

Avaliação de um Sistema de Reconhecimento de Atividade Humana baseado em Smartphone em uma Vida Diária Ambiente

An evaluation method that includes continuous activities in a daily-living environment was developed for Wearable Mobility Monitoring Systems (WMMS) that ...

Comportamento

Substantiating Appropriate Motion Capture Techniques for the Assessment of Nordic Walking Gait and Posture in Older Adults

Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques have been employed, each with positives and negatives. The aim was to determine the effect of NW on older adult gait and posture and to determine optimal use of different data collection systems in both short and long duration analysis. Gait and posture during NW and normal walking were assessed in 17 healthy older adults (age: 69 &#177; 7.3). Participants performed two trials of 6 Minute Walk Tests (6MWT) (1 with poles (WP) and 1 without poles (NP)) and 6 trials of a 5m walk (3 WP and 3 NP). Motion was recorded using two systems, a 6-sensor accelerometry system and an 8-camera 3-dimensional motion capture system, in order to quantify spatial-temporal, kinematic, and kinetic parameters.
With both systems, participants demonstrated increased stride length and double support and decreased gait speed and cadence WP compared to NP (p &#60;0.05). Also, with motion capture, larger single support time was found WP (p &#60;0.05). With 3-D capture, smaller hip power generation and moments of force were found at heel contact and pre-swing as well as smaller knee power absorption at heel contact, pre-swing, and terminal swing WP compared to NP, when assessed over one cycle (p &#60;0.05). Also, WP yielded smaller moments of force at heel contact and terminal swing along with larger moments at mid-stance of a gait cycle (p &#60;0.05). No changes were found for posture.
NW seems appropriate for promoting a normal gait pattern in older adults. Three-dimensional motion capture should primarily be used during short duration gait analysis (i.e. single gait cycle), while accelerometry systems should be primarily employed in instances requiring longer duration analysis such as during the 6MWT.

The aim was to substantiate optimal use of data collection techniques for Nordic walking gait and posture analysis. Three-dimensional motion capture should be used during short duration analysis (i.e. single gait cycle), while accelerometry should be employed for longer duration analysis (i.e. repeated cycles) like a 6 Minute Walk Test.

Fundamentar Técnicas Movimento de captura adequados à avaliação da marcha Nordic Walking e postura em adultos mais velhos

Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques ...

Reversible Cooling-induced Deactivations to Study Cortical Contributions to Obstacle Memory in the Walking Cat

On complex, naturalistic terrain, sensory information about an environmental obstacle can be used to rapidly adjust locomotor movements for avoidance. For example, in the cat, visual information about an impending obstacle can modulate stepping for avoidance. Locomotor adaptation can also occur independent of vision, as sudden tactile inputs to the leg by an expected obstacle can modify the stepping of all four legs for avoidance. Such complex locomotor coordination involves supraspinal structures, such as the parietal cortex. This protocol describes the use of reversible, cooling-induced cortical deactivation to assess parietal cortex contributions to memory-guided obstacle locomotion in the cat. Small cooling loops, known as cryoloops, are specially shaped to deactivate discrete regions of interest to assess their contributions to an overt behavior. Such methods have been used to elucidate the role of parietal area 5 in memory-guided obstacle avoidance in the cat.

Complex locomotion in naturalistic environments requiring careful coordination of the limbs involves regions of the parietal cortex. The following protocol describes the use of reversible cooling-induced deactivation to demonstrate the role of parietal area 5 in memory-guided obstacle avoidance in the walking cat.

Reversíveis induzida pelo resfriamento desativações para estudar Cortical contribuições para a memória do obstáculo o gato ambulante

On complex, naturalistic terrain, sensory information about an environmental obstacle can be used to rapidly adjust locomotor movements for avoidance. For ...

A Simple and Low-cost Assay for Measuring Ambulation in Mouse Models of Muscular Dystrophy

Measuring functional outcomes in the treatment of muscular dystrophy is an essential aspect of preclinical testing. The assessment of voluntary ambulation in mouse models is a non-invasive and reproducible activity assay that is directly analogous to measures of patient ambulation such as the 6-minute walk test and related mobility scores. Many common methods for testing mouse ambulation speed and distance are based on the open field test, where an animal&#39;s free movement within an arena is measured over time. One major downside to this approach is that commercial software and equipment for high-resolution motion tracking is expensive and may require transferring mice to specialized facilities for testing. Here, we describe a low-cost, video-based system for measuring mouse ambulation that utilizes free and open-source software. Using this protocol, we demonstrate that voluntary ambulation in the dystrophin-null mdx mouse model for Duchenne muscular dystrophy (DMD) is decreased relative to wild-type mouse activity. In mdx mice expressing the utrophin transgene, these activity deficits are not observed and the total distance traveled is indistinguishable from wild-type mice. This method is effective for measuring changes in voluntary ambulation associated with dystrophic pathology, and provides a versatile platform that can be readily adapted to diverse research settings.

This protocol describes a flexible, low-cost system for measuring mouse ambulation in an open field activity assay. We show that a 6-minute ambulation assay based on this system detects a decrease in voluntary movement in mdx mice, and accurately distinguishes improvement in a muscle-specific rescue of these animals.

Um ensaio simples e de baixo custo para medir a deambulação em modelos de Mouse de Distrofia Muscular

Measuring functional outcomes in the treatment of muscular dystrophy is an essential aspect of preclinical testing. The assessment of voluntary ambulation ...

Using Rapid Serial Visual Presentation to Measure Set-Specific Capture, a Consequence of Distraction While Multitasking

This method uses a rapid serial visual presentation (RSVP) paradigm to measure the cost of distraction when participants maintain multiple search goals. The protocol identifies two types of distraction within a single task - contingent attentional capture and set-specific capture - that represent different types of limitations of cognitive processing. Participants search for letters in two or more &#34;target&#34; ink colors (e.g., green and orange) within a continuous RSVP stream of heterogeneously colored letters, while ignoring two peripheral RSVPs of letters. Upon detecting a target, participants are to identify the letter. On some trials, target-colored distractors appear in the periphery just prior to the presentation of a target, causing a drop in target identification performance. Contingent attentional capture is observed by examining performance on trials in which the peripheral distractor is the same color as the target on that trial (e.g., both orange). Set-specific capture is represented by performance on trials in which the peripheral distractor is target-colored (e.g., orange), but not the same color as the target on that trial (e.g., green.) By varying the amount of time (i.e., the number of stimuli appearing) between the presentation of the distractor and the target, researchers can observe how participants recover from these distraction costs over time. As compared to static displays that are often used to measure contingent attentional capture, the dynamic display produces much larger effects, allowing the researcher to identify subtle effects of smaller manipulations. An unusual aspect of our design is that it employs a continuous display; &#34;filler&#34; stimuli connect one trial to the next seamlessly, and participants respond during this interval whenever they detect a target. The continuous display reduces chance performance to near-zero levels (rather than 50%) and provides researchers with a more sensitive measure of performance differences across trial types.

This method uses a dynamic visual display to index costs of distraction during visual search, including both &#34;contingent attentional capture&#34; and &#34;set-specific capture,&#34; which is a cost of distraction that occurs when the participants maintain multiple search goals simultaneously. This method has revealed basic mechanisms and limitations of visual attention.

Usando Rapid Serial Visual Presentation para medir o conjunto específico captura, uma consequência da distração enquanto multitarefa

This method uses a rapid serial visual presentation (RSVP) paradigm to measure the cost of distraction when participants maintain multiple search goals. ...

Using a Virtual Reality Walking Simulator to Investigate Pedestrian Behavior

To cross a road successfully, individuals must coordinate their movements with moving vehicles. This paper describes use of a walking simulator in which people walk on a treadmill to intercept gaps between two moving vehicles in an immersive virtual environment. Virtual reality allows for a safe and ecologically varied investigation of gap crossing behavior. Manipulating the initial starting distance can further the understanding of a participant&#8217;s speed regulation while approaching a gap. The speed profile may be assessed for various gap crossing variables, such as initial distance, vehicle size, and gap size. Each walking simulation results in a position/time series that can inform how velocity is adjusted differently depending on the gap characteristics. This methodology can be used by researchers investigating pedestrian behavior and behavioral dynamics while employing human participants in a safe and realistic setting.

This protocol describes use of a walking simulator that serves as a safe and ecologically valid method to study pedestrian behavior in the presence of moving traffic.

Usando um simulador de caminhada de realidade virtual para investigar o comportamento de pedestres

To cross a road successfully, individuals must coordinate their movements with moving vehicles. This paper describes use of a walking simulator in which ...

Lower-Limb Biomechanical Characteristics Associated with Unplanned Gait Termination Under Different Walking Speeds

Gait termination caused by unexpected stimulus is a common occurrence in everyday life. This study presents a protocol to investigate the lower-limb biomechanical changes that occur during unplanned gait termination (UGT) under different walking speeds. Fifteen male participants were asked to perform UGT on a walkway at normal walking speed (NWS) and fast walking speed (FWS), respectively. A motion analysis system and plantar pressure platform were applied to collect lower-limb kinematic and plantar pressure data. Paired-sampled T-test was used to examine the differences in lower-limb kinematics and plantar pressure data between two walking speeds. The results showed larger range of motion in the hip, knee, and ankle joints in the sagittal plane as well as plantar pressure in forefoot and heel regions during UGT at FWS when compared with NWS. With the increase in walking speed, subjects exhibited different lower-limb biomechanical characteristics that show FWS associated with greater potential injury risks.

This study compared the biomechanical characteristics of the lower extremity during unplanned gait termination under different walking speeds. The lower-limb kinematic and kinetic data from fifteen subjects with normal and fast walking speeds were collected using a motion analysis system and plantar pressure platform.

Características biomecânicas de membros inferiores associadas à terminação de marcha não planejada sob diferentes velocidades de caminhada

Gait termination caused by unexpected stimulus is a common occurrence in everyday life. This study presents a protocol to investigate the lower-limb ...

An Improved Assay and Tools for Measuring Mechanical Nociception in Drosophila Larvae

Published assays for mechanical nociception in Drosophila have led to variable assessments of behavior. Here, we fabricated, for use with Drosophila larvae, customized metal nickel-titanium alloy (nitinol) filaments. These mechanical probes are similar to the von Frey filaments used in vertebrates to measure mechanical nociception. Here, we demonstrate how to make and calibrate these mechanical probes and how to generate a full behavioral dose-response from subthreshold (innocuous or non-noxious range) to suprathreshold (low to high noxious range) stimuli. To demonstrate the utility of the probes, we investigated tissue damage-induced hypersensitivity in Drosophila larvae. Mechanical allodynia (hypersensitivity to a normally innocuous mechanical stimulus) and hyperalgesia (exaggerated responsiveness to a noxious mechanical stimulus) have not yet been established in Drosophila larvae. Using mechanical probes that are normally innocuous or probes that typically elicit an aversive behavior, we found that Drosophila larvae develop mechanical hypersensitization (both allodynia and hyperalgesia) after tissue damage. Thus, the mechanical probes and assay that we illustrate here will likely be important tools to dissect the fundamental molecular/genetic mechanisms of mechanical hypersensitivity.

An Improved Assay and Tools for Measuring Mechanical Nociception in Drosophila Larvae

The goal of this protocol is to show how to perform an improved assay for mechanical nociception in Drosophila larvae. We use the assay here to demonstrate that mechanical hypersensitivity (allodynia and hyperalgesia) exists in Drosophila larvae.

Um ensaio e ferramentas aprimoradas para medir o nocicepção mecânico em larvas de Drosophila

Published assays for mechanical nociception in Drosophila have led to variable assessments of behavior. Here, we fabricated, for use with Drosophila ...

Iterative Development of an Innovative Smartphone-Based Dietary Assessment Tool: Traqq

To collect dietary intake data in a fast and reliable manner, a flexible and innovative smartphone application (app) called Traqq was developed (iOS/Android). This app can be used as a food record and&#160;24-h recall (or shorter recall periods). Different sampling schemes can be created on either prespecified or random days/times within a predetermined period for both methods, with&#160;push notifications to urge the participants to register their food intake. In case of non-response, notifications are automatically rescheduled to ensure complete data collection. For use as a food record, respondents can access the app and log their food intake throughout the day. Food records close automatically at the end of the day; recalls close after submission of the consumed items. The recall as well as the food record module provide access to an extensive food list based on the Dutch food composition database (FCDB), which can be accustomed to fit different research purposes. When selecting a food item, respondents are simultaneously prompted to insert portion size, i.e., in household measures (e.g., cups, spoons, glasses), standard portion sizes (e.g., small, medium, large), or weight in grams, and eating occasion/time of consumption. Portion size options can be adjusted, e.g., only entry in grams in case of a weighed food record or time of consumption instead of eating occasion). The app also includes a My Dishes function, which allows the respondent to create their own recipes or product combinations (e.g., a daily breakfast) and only report the total quantity consumed. Subsequently, the app accounts for yield and retention factors. The data are stored on a secure server. If desired, additional questions, i.e., in general or those related to specific food items or eating occasions can be incorporated. This paper describes the development of the system (app and backend), including expert evaluations and usability testing.

This article describes the protocol for the development of an innovative smartphone-based dietary assessment application Traqq, including expert evaluations and usability testing.

Desenvolvimento Iterativo de uma ferramenta inovadora de avaliação dietética baseada em smartphones: Traqq

To collect dietary intake data in a fast and reliable manner, a flexible and innovative smartphone application (app) called Traqq was developed ...

Measuring the Behavioral Effects of Intraocular Scatter

Intraocular scatter, with its associated functional manifestations, is a leading cause of automotive accidents and a significant biomarker of covert and overt ocular disease (e.g., diseases of the cornea and lens). Nearly all current methods of measuring the behavioral consequences of light scatter, however, suffer from various limitations mostly reflecting a lack of construct and content validity: to wit, the measures do not adequately reflect real world conditions (e.g., artificial light vs. sunlight) or everyday tasks (e.g., recognition under visually demanding conditions).
This protocol describes two novel, ecologically valid methods of measuring the behavioral effects of intraocular scatter by quantifying scatter geometry and visual recognition under glare conditions. The former was measured by assessing the diameter of halos and spokes that resulted from a bright point source. Light spread (essentially, the point spread function determined using Rayleigh criteria) was quantified by determining the minimum perceivable distance between two small points of broad-band light. The latter was done based on the identification of letters formed using apertures through which bright light was shone.

In this protocol, we outline the conceptual design elements and structural development of a glare acuity apparatus. Additionally, the design of a device for measuring positive dysphotopsia (halos, spokes) and two-point light thresholds is described.

Medindo os efeitos comportamentais da dispersão intraocular

Intraocular scatter, with its associated functional manifestations, is a leading cause of automotive accidents and a significant biomarker of covert and ...