Yes / The aim of this study was to investigate age-related differences in dual task performance by using an upper limb proprioceptive task. Twenty-eight younger (18–30 years) and 28 older (>60 years) healthy adults performed circle tracing and serial subtraction tasks separately and concurrently. The tasks had two levels of difficulty: easy and hard. The circle tracing task included direct (easy) and indirect (hard) visual feedback conditions, and it was paired with serial subtraction by twos (easy) or threes (hard). We found that older adults were significantly slower than younger adults across all conditions and had significantly greater dual task costs when they performed circle tracing with easy serial subtraction. Higher levels of task difficulty were associated with slower speed in both groups. We found no age differences in accuracy. Participants either traded speed for accuracy or accuracy for speed regardless of age group. Overall, the findings suggest that speed and accuracy may be affected differently during dual tasking. In addition, older adults may rely more extensively on proprioceptive feedback to guide upper limb movement compared with younger adults. / Financial support for this study was obtained from the School of Psychology and Psychiatry, Monash University.

<p>Augmented reality (AR) allows people to view digital information overlaid on to real-world objects. While the technology is still new, it is currently being used in places such as the military and industrial assembly operations in the form of ocular devices worn on the head over the eyes. Head-mounted displays (HMDs) let people always see AR information in their field of view no matter where their head is positioned. Studies have shown that HMDs displaying information directly related to the immediate task can decreased cognitive workload and increase the speed and accuracy of task performance. However, task-irrelevant information has shown to decrease performance and accuracy of the primary task and also hinder the efficiency of processing the irrelevant information. This has been investigated in industry settings but less so in an everyday consumer context. This study proposes comparing two types of visual information (text and shapes) in AR displayed on an HMD to answer the following questions: 1) when content is of importance, which visual notification (text or shapes) is processed faster while degrading the performance of the primary task the least? And 2) When presence is of importance, which visual notification (text or shapes) is processed faster while degrading the performance of the primary task the least?</p>

Several lines of evidence from rapid serial visual presentation, attentional blink, and dual-task interference phenomena propose that human beings have a significant limitation on the short-term consolidation process. Short-term consolidation is transferring early representations to more durable forms of memory. Although previous research has shown that masks presented after targets interrupt the consolidation process of information, there is not enough evidence for the role of attention in consolidation for episodic memory. One electrophysiological and five behavioral experiments were conducted to investigate the effects of attention and stimulus onset asynchrony (SOA) between targets and masks on episodic memory. Masks were presented after targets with varying SOAs. The participants in the divided attention condition but not the ones in the full attention condition performed the attention-demanding secondary task after the presentation of the masks. The results showed that reducing SOA between targets and masks caused an impairment in memory performance for divided attention but not for full attention, providing evidence for the necessity of attention for the short-term consolidation process. Electrophysiological results demonstrated that this impairment did not result from perceptual processes.

The present study examined the divided attention effects of three non-speech tasks on concurrent speech motor performance. These tasks targeted linguistic, cognitive, and manual motor activity. Participants included 60 healthy adults separated into three different age groups of twenty participants each: college-age (20s), middle-aged (40s), and older adults (60s). Each participant completed a speech task once in isolation and once concurrently with each of the three non-speech tasks: a semantic decision task, a quantitative comparison task, and a manual motor task. The non-speech tasks were also performed in isolation. The speech task involved repeating a target phrase each time a beep sounded, for a total of fourteen repetitions. Dependent measures for speech were derived from lip kinematic recordings from a head-mounted strain gauge system. Dependent measures for the other tasks included timed response counts and accuracy rates. Results indicated significant divided attention effects, impacting speech and nonspeech measures in the linguistic and cognitive conditions, and impacting speech measures in the manual motor condition. A significant age effect for utterance duration was also found, as well as a divided attention interaction with age for cognitive task accuracy. The results add to what is known about bidirectional interference between speech and other concurrent tasks, as well as age effects on speech motor control.

<p>Research on backward response compatibility effects (Task 2-to-Task 1 response priming) in the Psychological Refractory Period (PRP) paradigm has suggested that compatibility effects arise from episodic representations of Stimulus-Response (S-R) pairings (Hommel & Eglau, 2002). However, more recent work suggests that these effects are mediated by S-R rules held online in working memory during dual task performance (Ellenbogen & Meiran, 2008). We sought to dissociate these accounts. In Experiment 1, we observed the development of backward response compatibility effects over time in a common PRP task, following varying degrees of prior single task practice of the PRP component tasks. In Experiment 2, we trained participants on a PRP dual task, and then switched Task 2 to one of three different tasks with variable response mapping overlap with the original Task 2, before finally reverting back to the original PRP tasks. Backward response compatibility effects appeared initially, were abolished during the subsequent interference phase, and then reappeared with the original PRP task. Despite equivalent overall performance across conditions suggesting successful task rule instantiation in working memory to guide task performance, backward response compatibility effects were selectively absent in conditions where current S-R rules were mapped in conflict with prior S-R experiences within the experiment. Both experiments provide evidence in favour of an episodic account of backward response compatibility effects, in which prior learning influences subsequent performance in contextually relevant situations. Implications for the understanding of backward response compatibility mechanisms and parallel processing in the PRP paradigm are discussed.</p> / Master of Science (MSc)

Desordens motoras são descritas no estágio final da doença de Alzheimer (DA), porém pesquisas recentes têm demonstrado que idosos com comprometimento cognitivo leve (CCL) e em fase inicial da DA apresentam alterações na marcha, especialmente em condições de atenção dividida (tarefa dupla). Esta pesquisa teve como objetivo avaliar o desempenho motor com e sem tarefa de atenção dividida em idosos com CCL e DA; e verificar se esta medida pode ser utilizada para diferenciar idosos cognitivamente saudáveis, com CCL e com DA. Foram avaliados 104 idosos (26 com DA leve, 42 com CCL e 36 cognitivamente saudáveis - controles) por meio do Timed Up and Go teste (TUG), em quatro condições experimentais: (1) tarefa simples (apenas o TUG), (2) TUG com tarefa cognitiva, (3) TUG com tarefa manual, e (4) tarefa tripla (com tarefa cognitiva e manual). Diferenças significativas foram observadas em todas as condições experimentais do TUG entre grupos diagnósticos, especialmente em relação ao tempo (em segundos) e número de passos (TUG 1-4) e paradas (TUG 2-4). Em relação à área sob a curva (AUC), as quatro formas do TUG apresentaram alto grau de discriminação entre os grupos diagnósticos em relação: 1) ao tempo (em segundos): AUC > 0,8 nos TUG 1 ao 4 entre os grupos controle e CCL (p<0,001), AUC > 0,9 nos TUG 1 ao 4 entre os grupos controle e DA (p<0,001), e AUC > 0,7 nos TUG 2 ao 4 entre os grupos CCL e DA (p<0,001); 2) número de passos: AUC >0,7 entre os grupos controle e CCL (p<0,001), AUC > 0,8 entre os grupos controle e DA (p<0,001), e AUC > 0,7 entre os grupos CCL e DA (p<0,02); 3) e número de paradas: AUC > 0,6 nos TUG 2 e 4 entre os grupos controle e CCL (p<0,05), AUC > 0,8 entre os grupos controle e DA nos TUG 2 e 4 (p<0,001) e AUC > 0,7 no TUG 2 entre os grupos CCL e DA (p<0,05). Portanto, o desempenho motor é afetado em idosos com CCL e em fases iniciais da DA em condições de tarefa simples e atenção dividida, sendo todas as condições do TUG boas medidas para diferenciar os grupos diagnósticos / Motor disorders are described in the final stages of Alzheimer\'s disease (AD), but recent research has shown that older adults with mild cognitive impairment (MCI) and early AD exhibit changes in gait, particularly under conditions of divided attention (dual task). This research aimed to evaluate motor performance with and without divided attention task in elderly with MCI and AD and verify that this measure can be used to differentiate elderly cognitively health, MCI and AD. A total of 104 older adults (26 with mild AD, 42 with MCI and 36 cognitively health - controls) were evaluated by the Timed Up and Go test (TUG) under four experimental conditions: (1) TUG simple task (TUG only); (2) TUG in association with a cognitive task; (3) TUG plus a manual task; and (4) TUG triple (plus a cognitive and manual task). Statistically significant differences in TUG were found between diagnostic groups in all experimental conditions, especially with respect to amount of time (in seconds) and number of steps (TUG 1-4) and stops (TUG 2-4). Regarding the area under the curve (AUC), all TUG tasks displayed a high accuracy level in discriminating between diagnostic groups: 1) amount of time (in seconds): AUC> 0.8 in TUG 1-4 between the control and MCI groups(p<0,001), AUC> 0.9 in TUG 1-4 between the control and AD groups(p<0,001), and AUC> 0.7 in TUG 2-4 between the MCI and AD groups(p<0,001); 2) the number of steps: AUC> 0.7 in TUG 1-4 between the control and MCI groups (p<0,001), AUC> 0.8 in TUG 1-4 between the control and AD groups (p<0,001), and AUC> 0.7 between in TUG 1-4 the MCI and AD groups (p<0,02); 3) and in the number of stops: AUC> 0.6 in TUGs 2-4 between the control and MCI groups (p<0,05), AUC> 0.8 in TUGs 2-4 between the control and AD groups (p<0,001) and AUC> 0.7 between the MCI and AD groups (p<0,05). Thus, motor performance is affected in older adults with MCI and early stages of AD, both with and without a divided attention task, and all conditions tested were able to differentiate among diagnostic groups

Regular use of illegal drugs is suspected to cause cognitive impairments. Two substances have received heightened attention: 3,4-methylenedioxymethamphetamine (MDMA or ‘ecstasy’) and δ-9-tetrahydrocannabinol (THC or ‘cannabis’). Preclinical evidence, as well as human studies examining regular ecstasy consumers, indicated that ecstasy use may have negative effects on learning, verbal memory and complex attentional functions. Cannabis has also been linked to symptoms of inattention and deficits in learning and memory. Most of the published studies in this field of research recruited participants by means of newspaper advertisements or by using word-of-mouth strategies. Because participants were usually aware that their drug use was critical to the research design, this awareness may have caused selection bias or created expectation effects. Focussing on attention and memory, this study aimed to assess cognitive functioning in a community-based representative sample that was derived from a large-scale epidemiological study. Available data concerning drug use history allowed sampling of subjects with varying degrees of lifetime drug experiences. Cognitive functioning was examined in 284 young participants, between 22 and 34 years. In general, their lifetime drug experience was moderate. Participants completed a neuropsychological test battery, including measures for verbal learning, memory and various attentional functions. Linear regression analysis was performed to investigate the relationship between cognitive functioning and lifetime experience of drug use. Ecstasy and cannabis use were significantly related to poorer episodic memory function in a dose-related manner. For attentional measures, decrements of small effect sizes were found. Error measures in tonic and phasic alertness tasks, selective attention task and vigilance showed small but significant effects, suggesting a stronger tendency to experience lapses of attention. No indication for differences in reaction time was found. The results are consistent with decrements of memory and attentional performance described in previous studies. These effects are relatively small; however, it must be kept in mind that this study focussed on assessing young adults with moderate drug use from a population-based study.

Desordens motoras são descritas no estágio final da doença de Alzheimer (DA), porém pesquisas recentes têm demonstrado que idosos com comprometimento cognitivo leve (CCL) e em fase inicial da DA apresentam alterações na marcha, especialmente em condições de atenção dividida (tarefa dupla). Esta pesquisa teve como objetivo avaliar o desempenho motor com e sem tarefa de atenção dividida em idosos com CCL e DA; e verificar se esta medida pode ser utilizada para diferenciar idosos cognitivamente saudáveis, com CCL e com DA. Foram avaliados 104 idosos (26 com DA leve, 42 com CCL e 36 cognitivamente saudáveis - controles) por meio do Timed Up and Go teste (TUG), em quatro condições experimentais: (1) tarefa simples (apenas o TUG), (2) TUG com tarefa cognitiva, (3) TUG com tarefa manual, e (4) tarefa tripla (com tarefa cognitiva e manual). Diferenças significativas foram observadas em todas as condições experimentais do TUG entre grupos diagnósticos, especialmente em relação ao tempo (em segundos) e número de passos (TUG 1-4) e paradas (TUG 2-4). Em relação à área sob a curva (AUC), as quatro formas do TUG apresentaram alto grau de discriminação entre os grupos diagnósticos em relação: 1) ao tempo (em segundos): AUC > 0,8 nos TUG 1 ao 4 entre os grupos controle e CCL (p<0,001), AUC > 0,9 nos TUG 1 ao 4 entre os grupos controle e DA (p<0,001), e AUC > 0,7 nos TUG 2 ao 4 entre os grupos CCL e DA (p<0,001); 2) número de passos: AUC >0,7 entre os grupos controle e CCL (p<0,001), AUC > 0,8 entre os grupos controle e DA (p<0,001), e AUC > 0,7 entre os grupos CCL e DA (p<0,02); 3) e número de paradas: AUC > 0,6 nos TUG 2 e 4 entre os grupos controle e CCL (p<0,05), AUC > 0,8 entre os grupos controle e DA nos TUG 2 e 4 (p<0,001) e AUC > 0,7 no TUG 2 entre os grupos CCL e DA (p<0,05). Portanto, o desempenho motor é afetado em idosos com CCL e em fases iniciais da DA em condições de tarefa simples e atenção dividida, sendo todas as condições do TUG boas medidas para diferenciar os grupos diagnósticos / Motor disorders are described in the final stages of Alzheimer\'s disease (AD), but recent research has shown that older adults with mild cognitive impairment (MCI) and early AD exhibit changes in gait, particularly under conditions of divided attention (dual task). This research aimed to evaluate motor performance with and without divided attention task in elderly with MCI and AD and verify that this measure can be used to differentiate elderly cognitively health, MCI and AD. A total of 104 older adults (26 with mild AD, 42 with MCI and 36 cognitively health - controls) were evaluated by the Timed Up and Go test (TUG) under four experimental conditions: (1) TUG simple task (TUG only); (2) TUG in association with a cognitive task; (3) TUG plus a manual task; and (4) TUG triple (plus a cognitive and manual task). Statistically significant differences in TUG were found between diagnostic groups in all experimental conditions, especially with respect to amount of time (in seconds) and number of steps (TUG 1-4) and stops (TUG 2-4). Regarding the area under the curve (AUC), all TUG tasks displayed a high accuracy level in discriminating between diagnostic groups: 1) amount of time (in seconds): AUC> 0.8 in TUG 1-4 between the control and MCI groups(p<0,001), AUC> 0.9 in TUG 1-4 between the control and AD groups(p<0,001), and AUC> 0.7 in TUG 2-4 between the MCI and AD groups(p<0,001); 2) the number of steps: AUC> 0.7 in TUG 1-4 between the control and MCI groups (p<0,001), AUC> 0.8 in TUG 1-4 between the control and AD groups (p<0,001), and AUC> 0.7 between in TUG 1-4 the MCI and AD groups (p<0,02); 3) and in the number of stops: AUC> 0.6 in TUGs 2-4 between the control and MCI groups (p<0,05), AUC> 0.8 in TUGs 2-4 between the control and AD groups (p<0,001) and AUC> 0.7 between the MCI and AD groups (p<0,05). Thus, motor performance is affected in older adults with MCI and early stages of AD, both with and without a divided attention task, and all conditions tested were able to differentiate among diagnostic groups

Ungdomar tillhör idag det som kallas den digitala generationen och äruppvuxna i en verklighet där tekniska redskap är en självklarhet.Mobiltelefonanvändning under lektionstid innebär deladuppmärksamhet. Tidigare forskning visar att användning av tekniskaredskap vid inlärning påverkar studenters akademiska prestationnegativt. Gymnasieelever är en sällan undersökt målpopulation isamband med uppmärksamhet och inlärning. Syftet med denna studievar att undersöka om mobiltelefonanvändning vid inlärning påverkargymnasieelevers minnesprestation. Ett experiment bestående av ettfriåtergivningstest och ett läsförståelsetest genomfördes med 49deltagare. Deltagarna som använde delad uppmärksamhet mottog ochsvarade på ett meddelande i sin mobiltelefon under inkodning.Resultatet visade att mobiltelefonanvändning vid inlärning påverkargymnasieelevers minnesprestation negativt vid läsförståelse. Merspecifikt påverkades manliga gymnasieelever mer av deladuppmärksamhet vid läsförståelse. / Adolescents today are part of what is called the digital generation andare raised in a reality where technical instruments are part of everydaylife. Cell phone use in class results in divided attention. Previousresearch has shown that usage of technical instruments during learninghas a negative impact on students’ academic performance. Highschool students are seldom the target population in studies concerningattention and learning. The purpose of this study was to investigatewhether cell phone use during learning affects high school students’memory performance. An experiment including a test of free recalland a test of reading comprehension was conducted with 49participants. The participants in the divided attention conditionreceived and responded to a message in their cell phones at encoding.The results showed that cell phone use during learning had a negativeimpact on high school students’ reading comprehension. Specifically,male high school students’ reading comprehension was more affectedby divided attention.

Regular use of illegal drugs is suspected to cause cognitive impairments. Two substances have received heightened attention: 3,4-methylenedioxymethamphetamine (MDMA or ‘ecstasy’) and δ-9-tetrahydrocannabinol (THC or ‘cannabis’). Preclinical evidence, as well as human studies examining regular ecstasy consumers, indicated that ecstasy use may have negative effects on learning, verbal memory and complex attentional functions. Cannabis has also been linked to symptoms of inattention and deficits in learning and memory. Most of the published studies in this field of research recruited participants by means of newspaper advertisements or by using word-of-mouth strategies. Because participants were usually aware that their drug use was critical to the research design, this awareness may have caused selection bias or created expectation effects. Focussing on attention and memory, this study aimed to assess cognitive functioning in a community-based representative sample that was derived from a large-scale epidemiological study. Available data concerning drug use history allowed sampling of subjects with varying degrees of lifetime drug experiences. Cognitive functioning was examined in 284 young participants, between 22 and 34 years. In general, their lifetime drug experience was moderate. Participants completed a neuropsychological test battery, including measures for verbal learning, memory and various attentional functions. Linear regression analysis was performed to investigate the relationship between cognitive functioning and lifetime experience of drug use. Ecstasy and cannabis use were significantly related to poorer episodic memory function in a dose-related manner. For attentional measures, decrements of small effect sizes were found. Error measures in tonic and phasic alertness tasks, selective attention task and vigilance showed small but significant effects, suggesting a stronger tendency to experience lapses of attention. No indication for differences in reaction time was found. The results are consistent with decrements of memory and attentional performance described in previous studies. These effects are relatively small; however, it must be kept in mind that this study focussed on assessing young adults with moderate drug use from a population-based study.