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Wyatt LE, Hewan PA, Hogeveen J, Spreng RN, Turner GR. Exploration versus exploitation decisions in the human brain: A systematic review of functional neuroimaging and neuropsychological studies. Neuropsychologia 2024; 192:108740. [PMID: 38036246 DOI: 10.1016/j.neuropsychologia.2023.108740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 10/15/2023] [Accepted: 11/21/2023] [Indexed: 12/02/2023]
Abstract
Thoughts and actions are often driven by a decision to either explore new avenues with unknown outcomes, or to exploit known options with predictable outcomes. Yet, the neural mechanisms underlying this exploration-exploitation trade-off in humans remain poorly understood. This is attributable to variability in the operationalization of exploration and exploitation as psychological constructs, as well as the heterogeneity of experimental protocols and paradigms used to study these choice behaviours. To address this gap, here we present a comprehensive review of the literature to investigate the neural basis of explore-exploit decision-making in humans. We first conducted a systematic review of functional magnetic resonance imaging (fMRI) studies of exploration-versus exploitation-based decision-making in healthy adult humans during foraging, reinforcement learning, and information search. Eleven fMRI studies met inclusion criterion for this review. Adopting a network neuroscience framework, synthesis of the findings across these studies revealed that exploration-based choice was associated with the engagement of attentional, control, and salience networks. In contrast, exploitation-based choice was associated with engagement of default network brain regions. We interpret these results in the context of a network architecture that supports the flexible switching between externally and internally directed cognitive processes, necessary for adaptive, goal-directed behaviour. To further investigate potential neural mechanisms underlying the exploration-exploitation trade-off we next surveyed studies involving neurodevelopmental, neuropsychological, and neuropsychiatric disorders, as well as lifespan development, and neurodegenerative diseases. We observed striking differences in patterns of explore-exploit decision-making across these populations, again suggesting that these two decision-making modes are supported by independent neural circuits. Taken together, our review highlights the need for precision-mapping of the neural circuitry and behavioural correlates associated with exploration and exploitation in humans. Characterizing exploration versus exploitation decision-making biases may offer a novel, trans-diagnostic approach to assessment, surveillance, and intervention for cognitive decline and dysfunction in normal development and clinical populations.
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Affiliation(s)
- Lindsay E Wyatt
- Department of Psychology, York University, Toronto, ON, Canada
| | - Patrick A Hewan
- Department of Psychology, York University, Toronto, ON, Canada
| | - Jeremy Hogeveen
- Department of Psychology, The University of New Mexico, Albuquerque, NM, USA
| | - R Nathan Spreng
- Montréal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montréal, QC, H3A 2B4, Canada; Department of Psychology, McGill University, Montréal, QC, Canada; Department of Psychiatry, McGill University, Montréal, QC, Canada; McConnell Brain Imaging Centre, Montréal Neurological Institute, McGill University, Montréal, QC, Canada.
| | - Gary R Turner
- Department of Psychology, York University, Toronto, ON, Canada.
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2
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Mantas V, Kotoula V, Pehlivanidis A. Exploring randomness in autism. PeerJ 2023; 11:e15751. [PMID: 37529214 PMCID: PMC10389071 DOI: 10.7717/peerj.15751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/23/2023] [Indexed: 08/03/2023] Open
Abstract
Introduction The fast, intuitive and autonomous system 1 along with the slow, analytical and more logical system 2 constitute the dual system processing model of decision making. Whether acting independently or influencing each other both systems would, to an extent, rely on randomness in order to reach a decision. The role of randomness, however, would be more pronounced when arbitrary choices need to be made, typically engaging system 1. The present exploratory study aims to capture the expression of a possible innate randomness mechanism, as proposed by the authors, by trying to isolate system 1 and examine arbitrary decision making in autistic participants with high functioning Autism Spectrum Disorders (ASD). Methods Autistic participants withhigh functioning ASD and an age and gender matched comparison group performed the random number generation task. The task was modified to limit the contribution of working memory and allow any innate randomness mechanisms expressed through system 1, to emerge. Results Utilizing a standard analyses approach, the random number sequences produced by autistic individuals and the comparison group did not differ in their randomness characteristics. No significant differences were identified when the sequences were examined using a moving window approach. When machine learning was used, random sequences' features could discriminate the groups with relatively high accuracy. Conclusions Our findings indicate the possibility that individual patterns during random sequence production could be consistent enough between groups to allow for an accurate discrimination between the autistic and the comparison group. In order to draw firm conclusions around innate randomness and further validate our experiment, our findings need to be replicated in a bigger sample.
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Affiliation(s)
- Vasileios Mantas
- 1st Department of Psychiatry, Aiginiteion Hospital, National and Kapodistrian University of Athens, Athens, Attica, Greece
| | | | - Artemios Pehlivanidis
- 1st Department of Psychiatry, Aiginiteion Hospital, National and Kapodistrian University of Athens, Athens, Attica, Greece
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3
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Williams RS, Adams NE, Hughes LE, Rouse MA, Murley AG, Naessens M, Street D, Holland N, Rowe JB. Syndromes associated with frontotemporal lobar degeneration change response patterns on visual analogue scales. Sci Rep 2023; 13:8939. [PMID: 37268659 DOI: 10.1038/s41598-023-35758-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/23/2023] [Indexed: 06/04/2023] Open
Abstract
Self-report scales are widely used in cognitive neuroscience and psychology. However, they rest on the central assumption that respondents engage meaningfully. We hypothesise that this assumption does not hold for many patients, especially those with syndromes associated with frontotemporal lobar degeneration. In this study we investigated differences in response patterns on a visual analogue scale between people with frontotemporal degeneration and controls. We found that people with syndromes associated with frontotemporal lobar degeneration respond with more invariance and less internal consistency than controls, with Bayes Factors = 15.2 and 14.5 respectively indicating strong evidence for a group difference. There was also evidence that patient responses feature lower entropy. These results have important implications for the interpretation of self-report data in clinical populations. Meta-response markers related to response patterns, rather than the values reported on individual items, may be an informative addition to future research and clinical practise.
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Affiliation(s)
- Rebecca S Williams
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Natalie E Adams
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, UK
| | - Laura E Hughes
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, UK
| | - Matthew A Rouse
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, UK
| | - Alexander G Murley
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, UK
| | - Michelle Naessens
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, UK
| | - Duncan Street
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, UK
| | - Negin Holland
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, UK
| | - James B Rowe
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, UK
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4
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Schlosser L, Naef N, Ehrler M, Wehrle F, Greutmann M, Oxenius A, Tuura R, Latal B, Brugger P. Counting on random number generation: Uncovering mild executive dysfunction in congenital heart disease. Brain Cogn 2023; 166:105955. [PMID: 36709638 DOI: 10.1016/j.bandc.2023.105955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 01/30/2023]
Abstract
Congenital heart disease (CHD) is associated with various neurocognitive deficits, particularly targeting executive functions (EFs), of which random number generation (RNG) is one indicator. RNG has, however, never been investigated in CHD. We administered the Mental Dice Task (MDT) to 67 young adults with CHD and 55 healthy controls. This 1-minute-task requires the generation of numbers 1 to 6 in a random sequence. RNG performance was correlated with a global EF score. Participants underwent MRI to examine structural-volumetric correlates of RNG. Compared to controls, CHD patients showed increased backward counting, reflecting deficient inhibition of automatized behavior. They also lacked a small-number bias (higher frequency of small relative to large numbers). RNG performance was associated with global EF scores in both groups. In CHD patients, MRI revealed an inverse association of counting bias with most of the volumetric measurements and the amount of small numbers was positively associated with corpus callosum volume, suggesting callosal involvement in the "pseudoneglect in number space". In conclusion, we found an impaired RNG performance in CHD patients, which is associated with brain volumetric measures. RNG, reportedly resistant to learning effects, may be an ideal task for the longitudinal assessment of EFs in patients with CHD.
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Affiliation(s)
- Ladina Schlosser
- Child Development Centre, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland; University Heart Center, Department of Cardiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091 Zurich, Switzerland.
| | - Nadja Naef
- Child Development Centre, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Melanie Ehrler
- Child Development Centre, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Flavia Wehrle
- Child Development Centre, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland; Department of Neonatology and Intensive Care, University Children's Hospital Zurich, Zurich, Switzerland
| | - Matthias Greutmann
- University Heart Center, Department of Cardiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Angela Oxenius
- University Heart Center, Department of Cardiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
| | - Ruth Tuura
- Children's Research Center, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Beatrice Latal
- Child Development Centre, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Peter Brugger
- Psychiatric University Clinic PUK, University Hospital Zurich, Lenggstrasse 31, PO Box 1931, 8032 Zurich, Switzerland; Neuropsychology Unit, Valens Rehabilitation Centre, Taminaplatz 1, 7317 Valens, Switzerland
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5
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Guseva M, Bogler C, Allefeld C, Haynes JD. Instruction effects on randomness in sequence generation. Front Psychol 2023; 14:1113654. [PMID: 37034908 PMCID: PMC10075230 DOI: 10.3389/fpsyg.2023.1113654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/20/2023] [Indexed: 04/11/2023] Open
Abstract
Randomness is a fundamental property of human behavior. It occurs both in the form of intrinsic random variability, say when repetitions of a task yield slightly different behavioral outcomes, or in the form of explicit randomness, say when a person tries to avoid being predicted in a game of rock, paper and scissors. Randomness has frequently been studied using random sequence generation tasks (RSG). A key finding has been that humans are poor at deliberately producing random behavior. At the same time, it has been shown that people might be better randomizers if randomness is only an implicit (rather than an explicit) requirement of the task. We therefore hypothesized that randomization performance might vary with the exact instructions with which randomness is elicited. To test this, we acquired data from a large online sample (n = 388), where every participant made 1,000 binary choices based on one of the following instructions: choose either randomly, freely, irregularly, according to an imaginary coin toss or perform a perceptual guessing task. Our results show significant differences in randomness between the conditions as quantified by conditional entropy and estimated Markov order. The randomization scores were highest in the conditions where people were asked to be irregular or mentally simulate a random event (coin toss) thus yielding recommendations for future studies on randomization behavior.
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Affiliation(s)
- Maja Guseva
- Bernstein Center for Computational Neuroscience, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Psychology, Humboldt Universität zu Berlin, Berlin, Germany
- *Correspondence: Maja Guseva,
| | - Carsten Bogler
- Bernstein Center for Computational Neuroscience, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Carsten Allefeld
- Department of Psychology, City University of London, London, United Kingdom
| | - John-Dylan Haynes
- Bernstein Center for Computational Neuroscience, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Psychology, City University of London, London, United Kingdom
- Berlin Center for Advanced Neuroimaging, Charité - Universitätsmedizin Berlin, Berlin, Germany
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6
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Mylius V, Maes L, Negele K, Schmid C, Sylvester R, Brook CS, Brugger F, Perez-Lloret S, Bansi J, Aminian K, Paraschiv-Ionescu A, Gonzenbach R, Brugger P. Dual-Task Treadmill Training for the Prevention of Falls in Parkinson's Disease: Rationale and Study Design. FRONTIERS IN REHABILITATION SCIENCES 2022; 2:774658. [PMID: 36188827 PMCID: PMC9397829 DOI: 10.3389/fresc.2021.774658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 12/22/2021] [Indexed: 11/13/2022]
Abstract
Various factors, such as fear of falling, postural instability, and altered executive function, contribute to the high risk of falling in Parkinson's disease (PD). Dual-task training is an established method to reduce this risk. Motor-perceptual task combinations typically require a patient to walk while simultaneously engaging in a perceptual task. Motor-executive dual-tasking (DT) combines locomotion with executive function tasks. One augmented reality treadmill training (AR-TT) study revealed promising results of a perceptual dual-task training with a markedly reduced frequency of falls especially in patients with PD. We here propose to compare the effects of two types of concurrent tasks, perceptual and executive, on high-intensity TT). Patients will be trained with TT alone, in combination with an augmented reality perceptual DT (AR-TT) or with an executive DT (Random Number Generation; RNG-TT). The results are expected to inform research on therapeutic strategies for the training of balance in PD.
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Affiliation(s)
- Veit Mylius
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
- Department of Neurology, Philipps University, Marburg, Germany
- Department of Neurology, Kantonsspital St. Gallen, St. Gallen, Switzerland
- *Correspondence: Veit Mylius
| | - Laura Maes
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
| | - Katrin Negele
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
| | - Christine Schmid
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
| | - Ramona Sylvester
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
| | | | - Florian Brugger
- Department of Neurology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Santiago Perez-Lloret
- Biomedical Research Center (CAECIHS-UAI), National Research Council (CONICET), Buenos Aires, Argentina
- Facultad de Medicina, Pontificia Universidad Católica Argentina, Buenos Aires, Argentina
- Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jens Bansi
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
- Department of Health, Physiotherapy, OST–Eastern Swiss University of Applied Sciences, St. Gallen, Switzerland
| | - Kamiar Aminian
- Laboratory of Movement Analysis and Measurement, EPFL, Lausanne, Switzerland
| | | | - Roman Gonzenbach
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
| | - Peter Brugger
- Department of Neurology, Center for Neurorehabilitation, Valens, Switzerland
- Department of Psychiatry, University of Zurich, Zurich, Switzerland
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7
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Delogu F, Barnewold M, Meloni C, Toffalini E, Zizi A, Fanari R. The Morra Game as a Naturalistic Test Bed for Investigating Automatic and Voluntary Processes in Random Sequence Generation. Front Psychol 2020; 11:551126. [PMID: 33071869 PMCID: PMC7541701 DOI: 10.3389/fpsyg.2020.551126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 09/02/2020] [Indexed: 11/13/2022] Open
Abstract
Morra is a 3,000-years-old hand game of prediction and numbers. The two players reveal their hand simultaneously, presenting a number of fingers between 1 and 5, while calling out a number between 2 and 10. Any player who successfully guesses the summation of fingers revealed by both players scores a point. While the game is extremely fast-paced, making it very difficult for players to achieve a conscious control of their game strategies, expert players regularly outperform non-experts, possibly with strategies residing out of conscious control. In this study, we used Morra as a naturalistic setting to investigate the necessity of attentive control in generation of sequence of items and the ability to proceduralize random number generation, which are both a crucial defensive strategy in Morra and a well-known empirical procedure to test the central executive capacity within the working memory model. We recorded the sequence of numbers generated by expert players in a Morra tournament in Sardinia (Italy) and by undergraduate students enrolled in a course-based research experience (CRE) course at Lawrence Technological University in the United States. Number sequences generated by non-expert and expert players both while playing Morra and in a random number generation task (RNGT) were compared in terms of randomness scores. Results indicate that expert players of Morra largely outperformed non-experts in the randomness scores only within Morra games, whereas in RNGT the two groups were very similar. Importantly, survey data acquired after the games indicate that expert players have very poor conscious recall of their number generation strategies used during the Morra game. Our results indicate that the ability of generating random sequences can be proceduralized and do not necessarily require attentive control. Results are discussed in the framework of the dual processing theory and its automatic-parallel-fast vs. controlled-sequential-slow polarities.
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Affiliation(s)
- Franco Delogu
- Department of Humanities, Social Sciences and Communication, Lawrence Technological University, Southfield, MI, United States
| | - Madison Barnewold
- Department of Humanities, Social Sciences and Communication, Lawrence Technological University, Southfield, MI, United States
| | - Carla Meloni
- Department of Pedagogy, Psychology, Philosophy, University of Cagliari, Cagliari, Italy
| | - Enrico Toffalini
- Department of General Psychology, University of Padua, Padua, Italy
| | - Antonello Zizi
- Department of Pedagogy, Psychology, Philosophy, University of Cagliari, Cagliari, Italy
| | - Rachele Fanari
- Department of Pedagogy, Psychology, Philosophy, University of Cagliari, Cagliari, Italy
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8
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Lesaffre L, Kuhn G, Jopp DS, Mantzouranis G, Diouf CN, Rochat D, Mohr C. Talking to the Dead in the Classroom: How a Supposedly Psychic Event Impacts Beliefs and Feelings. Psychol Rep 2020; 124:2427-2452. [PMID: 33019882 DOI: 10.1177/0033294120961068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Paranormal beliefs (PBs) are common in adults. There are numerous psychological correlates of PBs and associated theories, yet, we do not know whether such correlates reinforce or result from PBs. To understand causality, we developed an experimental design in which participants experience supposedly paranormal events. Thus, we can test an event's impact on PBs and PB-associated correlates. Here, 419 naïve students saw a performer making contact with a confederate's deceased kin. We tested participants' opinions and feelings about this performance, and whether these predicted how participants explain the performance. We assessed participants' PBs and repetition avoidance (PB related cognitive correlate) before and after the performance. Afterwards, participants rated explanations of the event and described their opinions and feelings (open-ended question). Overall, 65% of participants reported having witnessed a genuine paranormal event. The open-ended question revealed distinct opinion and affect groups, with reactions commonly characterized by doubt and mixed feelings. Importantly, paranormal explanations were more likely when participants reported their feelings than when not reported. Beyond these results, we replicated that 1) higher pre-existing PBs were associated with more psychic explanations (confirmation bias), and 2) PBs and repetition avoidance did not change from before to after the performance. Yet, PBs reminiscent of the actual performance (spiritualism) increased. Results showed that young adults easily endorse PBs and paranormal explanations for events, and that their affective reactions matter. Future studies should use participants' subjective experiences to target PBs in causal designs (e.g., adding control conditions).
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Affiliation(s)
- Lise Lesaffre
- Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland.,Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland
| | - Gustav Kuhn
- Psychology Department, Goldsmiths University of London, UK.,Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland
| | - Daniela S Jopp
- Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland; Swiss Centre of Competence in Research LIVES "Overcoming Vulnerability: Life Course Perspectives", Switzerland.,Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland
| | - Gregory Mantzouranis
- Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland; Unit of the University Department of Child and Adolescent Psychiatry (SUPEA), CHUV, Switzerland.,Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland
| | - Cécile Ndéyane Diouf
- Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland.,Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland
| | - Déborah Rochat
- Psychology Department, Faculty of Arts and Humanities, University of Fribourg, Switzerland.,Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland
| | - Christine Mohr
- Institute of Psychology, Social and Political Sciences, University of Lausanne, Switzerland
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Abstract
Free will is an apparent paradox because it requires a historical identity to escape its history in a self-guided fashion. Philosophers have itemized design features necessary for this escape, scaling from action to agency and vice versa. These can be organized into a coherent framework that neurocognitive capacities provide and that form a basis for neurocognitive free will. These capacities include (1) adaptive access to unpredictability, (2) tuning of this unpredictability in the service of hierarchical goal structures, (3) goal-directed deliberation via search over internal cognitive representations, and (4) a role for conscious construction of the self in the generation and choice of alternatives. This frames free will as a process of generative self-construction, by which an iterative search process samples from experience in an adaptively exploratory fashion, allowing the agent to explore itself in the construction of alternative futures. This provides an explanation of how effortful conscious control modulates adaptive access to unpredictability and resolves one of free will's key conceptual problems: how randomness is used in the service of the will. The implications provide a contemporary neurocognitive grounding to compatibilist and libertarian positions on free will, and demonstrate how neurocognitive understanding can contribute to this debate by presenting free will as an interaction between our freedom and our will.
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Affiliation(s)
- Thomas T Hills
- University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
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10
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Baena-Mirabete S, Espinal A, Puig P. Exploring the randomness of mentally generated head–tail sequences. STAT MODEL 2019. [DOI: 10.1177/1471082x18816410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
It is well known that people deviate from randomness as they attempt to mentally generate head–tail sequences as randomly as possible. This deviation from randomness is quantified by an excess of repetitions or alternations between successive responses more than would be expected by chance. We conducted an experiment in which a sample of students was asked to mentally simulate a sequence as if it is produced by a fair coin. We propose several models based on Markov chains for analysing the dynamic of head–tail outcomes in these sequences. First, we explore observed Markov chains and suggest some practical solutions to reduce the number of parameters. However, there is a need for more sophisticated models, and in this case, we propose latent Markov models and mixture of Markov chains to analyse these head–tail sequences. A generalization of the so-called mixture transition distribution (MTD) model is also considered.
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Affiliation(s)
- S Baena-Mirabete
- Department of Economics and Economic History, Faculty of Economics and Business Studies, Universitat Autónoma de Barcelona, Barcelona, Spain
- Department of Mathematics, Faculty of Sciences, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Anna Espinal
- Servei d'Estadística Aplicada, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Pedro Puig
- Department of Mathematics, Faculty of Sciences, Universitat Autónoma de Barcelona, Barcelona, Spain
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11
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Analyzing Human Random Generation: an Approach Based on the Zener Card Test. JOURNAL OF COGNITIVE ENHANCEMENT 2018. [DOI: 10.1007/s41465-018-0097-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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12
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Heuer H, Kohlisch O, Klein W. The Effects of Total Sleep Deprivation on the Generation of Random Sequences of Key-Presses, Numbers and Nouns. ACTA ACUST UNITED AC 2018; 58:275-307. [PMID: 15903118 DOI: 10.1080/02724980343000855] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
According to a recent hypothesis, executive functions should be particularly vulnerable to the effects of total sleep deprivation. Random generation is a task that taps executive functions. In three experiments we examined the effects of total sleep deprivation on random generation of keypresses, numbers, and nouns, in particular on the suppression of prepotent responses and the selection of next responses by way of applying a local-representativeness heuristic. With random key-presses suppression of prepotent responses did not suffer from lack of sleep, but it became poorer at a sufficiently high pacing rate. In contrast, suppression of prepotent responses suffered when numbers and nouns were generated. According to these findings different types of random generation tasks involve different types of inhibitory process. With only four response alternatives, but not with larger response sets, application of the local-representativeness heuristic was impaired after a night without sleep. In terms of a simple formal model, serial-order representations of the preceding responses are used in selecting the next response only for the small response set, and not for larger response sets. Thus, serial-order representations are likely to suffer from loss of sleep. These findings strongly suggest that random generation involves multiple processes and that total sleep deprivation does not impair all sorts of executive functions, but only some.
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Affiliation(s)
- Herbert Heuer
- Institut für Arbeitsphysiologie an der Universität Dortmund, Dortmund, Germany.
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13
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Gauvrit N, Zenil H, Soler-Toscano F, Delahaye JP, Brugger P. Human behavioral complexity peaks at age 25. PLoS Comput Biol 2017; 13:e1005408. [PMID: 28406953 PMCID: PMC5390965 DOI: 10.1371/journal.pcbi.1005408] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 02/10/2017] [Indexed: 12/03/2022] Open
Abstract
Random Item Generation tasks (RIG) are commonly used to assess high cognitive abilities such as inhibition or sustained attention. They also draw upon our approximate sense of complexity. A detrimental effect of aging on pseudo-random productions has been demonstrated for some tasks, but little is as yet known about the developmental curve of cognitive complexity over the lifespan. We investigate the complexity trajectory across the lifespan of human responses to five common RIG tasks, using a large sample (n = 3429). Our main finding is that the developmental curve of the estimated algorithmic complexity of responses is similar to what may be expected of a measure of higher cognitive abilities, with a performance peak around 25 and a decline starting around 60, suggesting that RIG tasks yield good estimates of such cognitive abilities. Our study illustrates that very short strings of, i.e., 10 items, are sufficient to have their complexity reliably estimated and to allow the documentation of an age-dependent decline in the approximate sense of complexity. It has been unclear how this ability evolves over a person’s lifetime and it had not been possible to be assessed with previous classical tools for statistical randomness. To better understand how age impacts behavior, we have assessed more than 3,400 people aged 4 to 91 years old. Each participant performed a series of online tasks that assessed their ability to behave randomly. The five tasks included listing the hypothetical results of a series of 12 coin flips so that they would “look random to somebody else,” guessing which card would appear when selected from a randomly shuffled deck, and listing the hypothetical results of 10 rolls of a die. We analyzed the participants’ choices according to their algorithmic randomness, which is based on the idea that patterns that are more random are harder to encode in a short computer program. After controlling for characteristics such as gender, language, and education. We have found that age was the only factor that affected the ability to behave randomly. This ability peaked at age 25, on average, and declined from then on. We also demonstrate that a relatively short list of choices, say 10 hypothetical coin flips, can be used to reliably gauge randomness of human behavior. A similar approach could be then used to study potential connections between the ability to behave randomly, cognitive decline, neurodegenerative diseases and abilities such as human creativity.
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Affiliation(s)
- Nicolas Gauvrit
- Algorithmic Nature Group, Laboratoire de Recherche Scientifique LABORES For the Natural and Digital Sciences, Paris, France
- Human and Artificial Cognition Lab, EPHE, Paris, France
| | - Hector Zenil
- Algorithmic Nature Group, Laboratoire de Recherche Scientifique LABORES For the Natural and Digital Sciences, Paris, France
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
- Information Dynamics Lab, Unit of Computational Medicine, Department of Medicine Solna, Centre for Molecular Medicine and Science for Life Laboratory (SciLifeLab), Karolinska Institute, Stockholm, Sweden
- * E-mail:
| | - Fernando Soler-Toscano
- Algorithmic Nature Group, Laboratoire de Recherche Scientifique LABORES For the Natural and Digital Sciences, Paris, France
- Grupo de Lógica, Lenguaje e Información. Universidad de Sevilla, Sevilla, Spain
| | - Jean-Paul Delahaye
- Algorithmic Nature Group, Laboratoire de Recherche Scientifique LABORES For the Natural and Digital Sciences, Paris, France
- Centre de Recherche en Informatique, Signal et Automatique de Lille (CRISTAL), UMR CNRS 9189, University of Lille 1, Lille, France
| | - Peter Brugger
- Algorithmic Nature Group, Laboratoire de Recherche Scientifique LABORES For the Natural and Digital Sciences, Paris, France
- Department of Neurology, Neuropsychology Unit, University Hospital, Zurich, Switzerland
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Baranger K, Bonnet AE, Girard SD, Paumier JM, García-González L, Elmanaa W, Bernard A, Charrat E, Stephan D, Bauer C, Moschke K, Lichtenthaler SF, Roman FS, Checler F, Khrestchatisky M, Rivera S. MT5-MMP Promotes Alzheimer's Pathogenesis in the Frontal Cortex of 5xFAD Mice and APP Trafficking in vitro. Front Mol Neurosci 2017; 9:163. [PMID: 28119565 PMCID: PMC5223243 DOI: 10.3389/fnmol.2016.00163] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/16/2016] [Indexed: 12/18/2022] Open
Abstract
We previously reported that deficiency of membrane-type five matrix metalloproteinase (MT5-MMP) prevents amyloid pathology in the cortex and hippocampus of 5xFAD mice, and ameliorates the functional outcome. We have now investigated whether the integrity of another important area affected in Alzheimer's disease (AD), the frontal cortex, was also preserved upon MT5-MMP deficiency in 4-month old mice at prodromal stages of the pathology. We used the olfactory H-maze (OHM) to show that learning impairment associated with dysfunctions of the frontal cortex in 5xFAD was prevented in bigenic 5xFAD/MT5-MMP-/- mice. The latter exhibited concomitant drastic reductions of amyloid beta peptide (Aβ) assemblies (soluble, oligomeric and fibrillary) and its immediate precursor, C99. Simultaneously, astrocyte reactivity and tumor necrosis factor alpha (TNF-α) levels were also lowered. Moreover, MT5-MMP deficiency induced a decrease in N-terminal soluble fragments of amyloid precursor protein (APP), including soluble APPα (sAPPα), sAPPβ and the MT5-MMP-linked fragment of 95 kDa, sAPP95. However, the lack of MT5-MMP did not affect the activity of β- and γ-secretases. In cultured HEKswe cells, transiently expressed MT5-MMP localized to early endosomes and increased the content of APP and Aβ40 in these organelles, as well as Aβ levels in cell supernatants. This is the first evidence that the pro-amyloidogenic features of MT5-MMP lie, at least in part, on the ability of the proteinase to promote trafficking into one of the amyloidogenic subcellular loci. Together, our data further support the pathogenic role of MT5-MMP in AD and that its inhibition improves the functional and pathological outcomes, in this case in the frontal cortex. These data also support the idea that MT5-MMP could become a novel therapeutic target in AD.
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Affiliation(s)
- Kévin Baranger
- Aix Marseille Université, CNRS, NICN UMR 7259 Marseille, France
| | | | | | | | | | - Wejdane Elmanaa
- Université Côte d'Azur, INSERM, CNRS, IPMC, Laboratory of excellence DistALZ, Sophia-Antipolis Valbonne, France
| | - Anne Bernard
- Aix Marseille Université, CNRS, NICN UMR 7259 Marseille, France
| | - Eliane Charrat
- Aix Marseille Université, CNRS, NICN UMR 7259 Marseille, France
| | | | - Charlotte Bauer
- Université Côte d'Azur, INSERM, CNRS, IPMC, Laboratory of excellence DistALZ, Sophia-Antipolis Valbonne, France
| | - Katrin Moschke
- German Center for Neurodegenerative Diseases (DZNE) Munich, Germany
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE)Munich, Germany; Neuroproteomics, Klinikum rechts der Isar, and Institute for Advanced Study, Technische Universität München (TUM)Munich, Germany; Munich Cluster for Systems Neurology (SyNergy)Munich, Germany
| | | | - Frédéric Checler
- Université Côte d'Azur, INSERM, CNRS, IPMC, Laboratory of excellence DistALZ, Sophia-Antipolis Valbonne, France
| | | | - Santiago Rivera
- Aix Marseille Université, CNRS, NICN UMR 7259 Marseille, France
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Strenge H, Böhm J. Effects of Regular Switching between Languages during Random Number Generation. Percept Mot Skills 2016; 100:524-34. [PMID: 15974362 DOI: 10.2466/pms.100.2.524-534] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Random number generation is a task that engages working memory and executive processes within the domain of number representation. In the present study we address the role of language in number processing by switching languages during random number generation (numbers 1–9), using German (L1) and English (L2), and alternating L1/L2. Results indicate large correspondence between performance in L1 and L2. In contrast to nonswitching performance, randomization with alternating languages showed a significant increase of omitted responses, whereas the random sequences were less stereotyped, showing significantly less repetition avoidance and cycling behavior. During an intentional switch between languages, errors in language sequence appeared in 23% of responses on the average, independently of the quality of randomization but associated with a clear persistence of L2. These results indicate that random number generation is more closely linked to auditory-phonological representation of numerals than to visual arabic notation.
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Affiliation(s)
- Hans Strenge
- Institute of Medical Psychology, University of Kiel, Germany.
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16
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Moser I, Vibert D, Caversaccio MD, Mast FW. Acute peripheral vestibular deficit increases redundancy in random number generation. Exp Brain Res 2016; 235:627-637. [PMID: 27847985 DOI: 10.1007/s00221-016-4829-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 11/09/2016] [Indexed: 11/29/2022]
Abstract
Unilateral peripheral vestibular deficit leads to broad cognitive difficulties and biases in spatial orientation. More specifically, vestibular patients typically show a spatial bias toward their affected ear in the subjective visual vertical, head and trunk orientation, fall tendency, and walking trajectory. By means of a random number generation task, we set out to investigate how an acute peripheral vestibular deficit affects the mental representation of numbers in space. Furthermore, the random number generation task allowed us to test if patients with peripheral vestibular deficit show evidence of impaired executive functions while keeping the head straight and while performing active head turns. Previous research using galvanic vestibular stimulation in healthy people has shown no effects on number space, but revealed increased redundancy of the generated numbers. Other studies reported a spatial bias in number representation during active and passive head turns. In this experiment, we tested 43 patients with acute vestibular neuritis (18 patients with left-sided and 25 with right-sided vestibular deficit) and 28 age-matched healthy controls. We found no bias in number space in patients with peripheral vestibular deficit but showed increased redundancy in patients during active head turns. Patients showed worse performance in generating sequences of random numbers, which indicates a deficit in the updating component of executive functions. We argue that RNG is a promising candidate for a time- and cost-effective assessment of executive functions in patients suffering from a peripheral vestibular deficit.
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Affiliation(s)
- Ivan Moser
- Department of Psychology, University of Bern, Fabrikstrasse 8, Bern, 3012, Switzerland.
- Center for Cognition, Learning and Memory, University of Bern, Fabrikstrasse 8, Bern, 3012, Switzerland.
| | - Dominique Vibert
- Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, University of Bern, Bern, Switzerland
| | - Marco D Caversaccio
- Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, University of Bern, Bern, Switzerland
| | - Fred W Mast
- Department of Psychology, University of Bern, Fabrikstrasse 8, Bern, 3012, Switzerland
- Center for Cognition, Learning and Memory, University of Bern, Fabrikstrasse 8, Bern, 3012, Switzerland
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Multani N, Rudzicz F, Wong WYS, Namasivayam AK, van Lieshout P. Random Item Generation Is Affected by Age. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2016; 59:1172-1178. [PMID: 27681687 DOI: 10.1044/2016_jslhr-l-15-0077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 01/25/2016] [Indexed: 06/06/2023]
Abstract
PURPOSE Random item generation (RIG) involves central executive functioning. Measuring aspects of random sequences can therefore provide a simple method to complement other tools for cognitive assessment. We examine the extent to which RIG relates to specific measures of cognitive function, and whether those measures can be estimated using RIG only. METHOD Twelve healthy older adults (age: M = 70.3 years, SD = 4.9; 8 women and 4 men) and 20 healthy young adults (age: M = 24 years, SD = 4.0; 12 women and 8 men) participated in this pilot study. Each completed a RIG task, along with the color Stroop test, the Repeatable Battery for the Assessment of Neuropsychological Status, and the Peabody Picture Vocabulary Test-Fourth Edition (Dunn & Dunn, 2007). Several statistical features extracted from RIG sequences, including recurrence quantification, were found to be related to the other measures through correlation, regression, and a neural-network model. RESULTS The authors found significant effects of age in RIG and demonstrate that nonlinear machine learning can use measures of RIG to accurately predict outcomes from other tools. CONCLUSIONS These results suggest that RIG can be used as a relatively simple predictor for other tools and in particular seems promising as a potential screening tool for selective attention in healthy aging.
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Affiliation(s)
- Namita Multani
- Oral Dynamics Lab, University of Toronto, Ontario, Canada
| | - Frank Rudzicz
- University of Toronto, Ontario, CanadaRehabilitation Sciences Institute, University of Toronto, Ontario, CanadaToronto Rehabilitation Institute-University Health Network, Ontario, Canada
| | | | - Aravind Kumar Namasivayam
- Oral Dynamics Lab, University of Toronto, Ontario, CanadaToronto Rehabilitation Institute-University Health Network, Ontario, Canada
| | - Pascal van Lieshout
- Oral Dynamics Lab, University of Toronto, Ontario, CanadaUniversity of Toronto, Ontario, CanadaRehabilitation Sciences Institute, University of Toronto, Ontario, CanadaToronto Rehabilitation Institute-University Health Network, Ontario, CanadaInstitute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario, Canada
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Geisseler O, Pflugshaupt T, Buchmann A, Bezzola L, Reuter K, Schuknecht B, Weller D, Linnebank M, Brugger P. Random number generation deficits in patients with multiple sclerosis: Characteristics and neural correlates. Cortex 2016; 82:237-243. [DOI: 10.1016/j.cortex.2016.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 04/23/2016] [Accepted: 05/12/2016] [Indexed: 10/21/2022]
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Abstract
The effects of different levels of language proficiency on random number generation were examined in this study. 16 healthy right-handed students (7 women, 9 men; aged 22 to 25 years, M = 23.8, SD = .83) attempted to generate a random sequence of the digits 1 to 9 at pacing frequencies of 1, 1.5, and 2 Hz. Randomization was done in German (native language L1), English (first foreign language L2), and French (second foreign language L3). There was a pattern of redundancy and seriation tendencies, increasing with speed of generation for all languages (L1–L3). While using L2 and L3, responses slowed and the number of errors committed increased. Further, there was a peculiar pattern of dissociation in nonrandom performance with an increase of habitual counting in ones and a strong reduction of counting in twos. All effects were most pronounced when subjects used L3 and 2-Hz pacing rates. Slowing and nonrandomness was not correlated with self-assessment parameters regarding language proficiency. We suggest that in a task involving number activation in a nonnative language, lack of proficiency will interfere with random number generation, leading to interruptions and rule breaking, at least when reaching the limits of attentional capacity at higher pacing rates.
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Affiliation(s)
- Hans Strenge
- Institute of Medical Psychology, University of Kiel, Germany.
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20
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Tobler-Ammann BC, de Bruin ED, Brugger P, de Bie RA, Knols RH. The Zürich Maxi Mental Status Inventory (ZüMAX): Test-Retest Reliability and Discriminant Validity in Stroke Survivors. Cogn Behav Neurol 2016; 29:78-90. [PMID: 27336805 DOI: 10.1097/wnn.0000000000000094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To examine discriminant validity and test-retest reliability of the Zürich maxi mental status inventory (ZüMAX) in patients with stroke. BACKGROUND The ZüMAX is a novel domain-specific cognitive assessment tool to screen for disturbances in neuropsychological function. The test can be used in stroke rehabilitation to estimate severity of cognitive impairment. Because evidence for validity and reliability is lacking, the tool's clinical use is limited. METHODS We administered the ZüMAX in a test-retest design to 33 community-dwelling stroke survivors, and once to 35 healthy controls matched for age and sex. RESULTS We found significant group differences in subscores for the cognitive domains of executive functions and language as well as total score (P=0.001 to 0.004); we did not find group differences for the domains of praxia (defined as the ability to perform purposeful actions), visual perception and construction, or learning and memory. Test-retest reliability of the total score was good (intraclass correlation coefficient=0.81), with the individual domain subscores ranging from poor to fair (0.59 to 0.79). The ZüMAX could detect changes in patients with low smallest detectable differences in executive functions, language, and praxia (0.05 to 1.49) and total score (0.09). CONCLUSION The ZüMAX has moderate to good test-retest reliability. Furthermore, the tool might discriminate between healthy persons and chronic stroke survivors on three of five subscales. The ZüMAX shows promise in measuring neuropsychological disturbances in stroke survivors; however, further trials are required with larger samples.
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Affiliation(s)
- Bernadette C Tobler-Ammann
- *Physiotherapy and Occupational Therapy Research Center, Directorate of Research and Education, University Hospital Zürich, Zürich, Switzerland ∥Neuropsychology, Department of Neurology, University Hospital Zürich, Zürich, Switzerland ‡Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule (ETH) Zürich (Swiss Federal Institute of Technology), Zürich, Switzerland †Department of Epidemiology, Care and Public Health Research Institute (CAPHRI) School for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands §Centre for Evidence Based Physiotherapy, Maastricht University, Maastricht, The Netherlands
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21
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Information-Theoretic Neuro-Correlates Boost Evolution of Cognitive Systems. ENTROPY 2015. [DOI: 10.3390/e18010006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Adenosine, caffeine, and performance: from cognitive neuroscience of sleep to sleep pharmacogenetics. Curr Top Behav Neurosci 2014; 25:331-66. [PMID: 24549722 DOI: 10.1007/7854_2014_274] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
An intricate interplay between circadian and sleep-wake homeostatic processes regulate cognitive performance on specific tasks, and individual differences in circadian preference and sleep pressure may contribute to individual differences in distinct neurocognitive functions. Attentional performance appears to be particularly sensitive to time of day modulations and the effects of sleep deprivation. Consistent with the notion that the neuromodulator, adenosine , plays an important role in regulating sleep pressure, pharmacologic and genetic data in animals and humans demonstrate that differences in adenosinergic tone affect sleepiness, arousal and vigilant attention in rested and sleep-deprived states. Caffeine--the most often consumed stimulant in the world--blocks adenosine receptors and normally attenuates the consequences of sleep deprivation on arousal, vigilance, and attention. Nevertheless, caffeine cannot substitute for sleep, and is virtually ineffective in mitigating the impact of severe sleep loss on higher-order cognitive functions. Thus, the available evidence suggests that adenosinergic mechanisms, in particular adenosine A2A receptor-mediated signal transduction, contribute to waking-induced impairments of attentional processes, whereas additional mechanisms must be involved in higher-order cognitive consequences of sleep deprivation. Future investigations should further clarify the exact types of cognitive processes affected by inappropriate sleep. This research will aid in the quest to better understand the role of different brain systems (e.g., adenosine and adenosine receptors) in regulating sleep, and sleep-related subjective state, and cognitive processes. Furthermore, it will provide more detail on the underlying mechanisms of the detrimental effects of extended wakefulness, as well as lead to the development of effective, evidence-based countermeasures against the health consequences of circadian misalignment and chronic sleep restriction.
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Monteiro M, Peixoto B. Behavioural Assessment of the Dysexecutive Syndrome (BADS) no contexto do envelhecimento normal e patológico. REVISTA BRASILEIRA DE GERIATRIA E GERONTOLOGIA 2014. [DOI: 10.1590/s1809-98232014000200017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Vários autores advogam a necessidade de avaliar o funcionamento executivo como um determinante robusto do estado funcional do indivíduo e como potencial marcador de demência. Contudo, existem poucos instrumentos que permitem avaliar diferentes componentes do funcionamento executivo no contexto do envelhecimento normal e patológico. O presente trabalho teve como objectivo determinar as propriedades psicométricas da Behavioral Assessment of the Dysexecutive Syndrome (BADS), tais como aceitabilidade, validade de constructo (validade discriminativa) e, paralelamente, validade de critério em contexto de envelhecimento numa amostra portuguesa. Esta compreendeu 33 sujeitos com mais de 65 anos de idade divididos em dois grupos: Gupo Controlo (n=22), composto por sujeitos cognitivamente incólumes; Grupo Demência (n=11), constituído por sujeitos com o diagnóstico provável de doença de Alzheimer (critérios NINCDS-ARDA). A ambos grupos foram aplicadas a BADS, a Dementia Rating Scale-2 e a Escala de Depressão Geriátrica. A BADS evidenciou bons níveis de aceitação, consistência interna e de validade discriminativa e de critério. Os resultados favorecem o uso deste instrumento no contexto do envelhecimento e demência, que pode ser útil na monitorização do funcionamento executivo e na deteção de demência.
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Affiliation(s)
| | - Bruno Peixoto
- Instituto Superior de Ciências da Saúde-Norte, Portugal; Instituto Superior de Ciências da Saúde-Norte, Portugal
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Di Bono MG, Zorzi M. The Spatial Representation of Numerical and Non-Numerical Ordered Sequences: Insights from a Random Generation Task. Q J Exp Psychol (Hove) 2013; 66:2348-62. [DOI: 10.1080/17470218.2013.779730] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
It is widely believed that numbers are spatially represented from left to right on the mental number line. Whether this spatial format of representation is specific to numbers or is shared by non-numerical ordered sequences remains controversial. When healthy participants are asked to randomly generate digits they show a systematic small-number bias that has been interpreted in terms of “pseudoneglect in number space”. Here we used a random generation task to compare numerical and non-numerical order. Participants performed the task at three different pacing rates and with three types of stimuli (numbers, letters, and months). In addition to a small-number bias for numbers, we observed a bias towards “early” items for letters and no bias for months. The spatial biases for numbers and letters were rate independent and similar in size, but they did not correlate across participants. Moreover, letter generation was qualified by a systematic forward direction along the sequence, suggesting that the ordinal dimension was more salient for letters than for numbers in a task that did not require its explicit processing. The dissociation between numerical and non-numerical orders is consistent with electrophysiological and neuroimaging studies and suggests that they rely on at least partially different mechanisms.
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Affiliation(s)
| | - Marco Zorzi
- Department of General Psychology and Centre for Cognitive Science, University of Padova, Padova, Italy
- IRCCS San Camillo Hospital, Lido-Venezia, Italy
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Response randomization of one- and two-person rock-paper-scissors games in individuals with schizophrenia. Psychiatry Res 2013; 207:158-63. [PMID: 23017652 DOI: 10.1016/j.psychres.2012.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 09/04/2012] [Accepted: 09/05/2012] [Indexed: 11/22/2022]
Abstract
Randomization among successive choices is important in adaptive decision-making, particularly for strategic interactions in which the optimal strategy is a mixed strategy. Patients with schizophrenia have been reported to have deficits in random sequential behaviors arising from impaired executive function. However, whether schizophrenic patients exhibit distinct behaviors for response randomization in one- and two-person games requiring different behavioral strategies is not known. The aim of this study was to examine the response randomization of 48 schizophrenic patients and 50 healthy subjects in one- and two-person rock-paper-scissors games. Here we found that the schizophrenic patients exhibited non-random biases distinct from those of the healthy subjects (i.e., stereotypic switching in the one-person game and the tendency to choose the best response against the opponent's previous choice in the two-person game). The entropy of the choice sequences was prominently decreased in the schizophrenic patients for both games, thereby indicating an overall disturbance in the behavioral randomization in adaptive decision-making. These results suggest that the impairment of response randomization in schizophrenic patients manifests differently in interactive and non-interactive situations, which may be useful for the diagnosis and quantification of the severity of the disease.
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Marsh JE, Sörqvist P, Halin N, Nöstl A, Jones DM. Auditory distraction compromises random generation. Falling back into old habits? Exp Psychol 2013; 60:279-92. [PMID: 23548984 DOI: 10.1027/1618-3169/a000198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Auditory distraction of random generation--a quintessentially executive control task--was explored in three experiments. Random number generation was impaired by the mere presence of irrelevant auditory sequences that comprise digits, but not letters, and then only if the digits were heard in a canonical order (1, 2, 3 … or 3, 2, 1 …), not in random order (Experiments 1 and 2). Random letter generation was impaired by irrelevant letters heard in alphabetical order (a, b, c …) and reversed alphabetical order (i, h, g …), but not by numbers in canonical order or letters in random order (Experiment 3). Attempting to ignore canonical sequences--with items that are members of the same category as the to-be-generated items--reduced the randomness of the generated sequence, by decreasing the tendency to change the direction of the produced sequence for random number generation, and by increasing resampling of responses for random letter generation. Like other selective attention tasks, the cost of distraction to random generation appears to stem from preventing habitual responses assuming the control of action.
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Affiliation(s)
- John E Marsh
- School of Psychology, University of Central Lancashire, Preston, UK.
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Aretouli E, Tsilidis KK, Brandt J. Four-year outcome of mild cognitive impairment: the contribution of executive dysfunction. Neuropsychology 2012; 27:95-106. [PMID: 23106114 DOI: 10.1037/a0030481] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE The contribution of executive cognition (EC) to the prediction of incident dementia remains unclear. This prospective study examined the predictive value of EC for subsequent cognitive decline in persons with mild cognitive impairment (MCI) over a 4-year period. METHOD One hundred forty-one persons with MCI (amnestic and nonamnestic, single- and multiple-domain) received a baseline and two biennial follow-up assessments. Eighteen tests, assessing six different aspects of EC, were administered at baseline and at 2-year follow-up, together with screening cognitive and daily functioning measures. Longitudinal logistic regression models and generalized estimating equations (GEE) were used to examine whether EC could predict progression to a Clinical Dementia Rating Scale (CDR; C. P. Hughes, L. Berg, W. L. Danziger, L. A. Coben, & R. L. Martin, 1982, A new clinical scale for the staging of dementia, British Journal of Psychiatry, Vol. 140, pp. 566-572) score of 1 or more over the 4-year period, first at the univariate level and then in the context of demographic and clinical characteristics, daily functioning measures, and other neurocognitive factors. RESULTS Over the 4-year period, 56% of MCI patients remained stable, 35% progressed to CDR ≥ 1, and 8% reverted to normal (CDR = 0). Amnestic MCI subtypes were not associated with higher rates of progression to dementia, whereas subtypes with multiple impairments were so associated. Eight out of the 18 EC measures, including all three measures assessing inhibition of prepotent responses, predicted MCI outcome at the univariate level. However, the multivariate GEE model indicated that age, daily functioning, and overall cognitive functioning best predicted progression to dementia. CONCLUSION Measures of EC (i.e., inhibitory control) are associated with MCI outcome. However, age and global measures of cognitive and functional impairment are better predictors of incident dementia.
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Affiliation(s)
- Eleni Aretouli
- Departments of Psychiatry and Behavioral Sciences and Neurology, Johns Hopkins University School of Medicine
| | | | - Jason Brandt
- Departments of Psychiatry and Behavioral Sciences and Neurology, Johns Hopkins University School of Medicine
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Schulz MA, Schmalbach B, Brugger P, Witt K. Analysing humanly generated random number sequences: a pattern-based approach. PLoS One 2012; 7:e41531. [PMID: 22844490 PMCID: PMC3402418 DOI: 10.1371/journal.pone.0041531] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 06/27/2012] [Indexed: 11/25/2022] Open
Abstract
In a random number generation task, participants are asked to generate a random sequence of numbers, most typically the digits 1 to 9. Such number sequences are not mathematically random, and both extent and type of bias allow one to characterize the brain's “internal random number generator”. We assume that certain patterns and their variations will frequently occur in humanly generated random number sequences. Thus, we introduce a pattern-based analysis of random number sequences. Twenty healthy subjects randomly generated two sequences of 300 numbers each. Sequences were analysed to identify the patterns of numbers predominantly used by the subjects and to calculate the frequency of a specific pattern and its variations within the number sequence. This pattern analysis is based on the Damerau-Levenshtein distance, which counts the number of edit operations that are needed to convert one string into another. We built a model that predicts not only the next item in a humanly generated random number sequence based on the item′s immediate history, but also the deployment of patterns in another sequence generated by the same subject. When a history of seven items was computed, the mean correct prediction rate rose up to 27% (with an individual maximum of 46%, chance performance of 11%). Furthermore, we assumed that when predicting one subject′s sequence, predictions based on statistical information from the same subject should yield a higher success rate than predictions based on statistical information from a different subject. When provided with two sequences from the same subject and one from a different subject, an algorithm identifies the foreign sequence in up to 88% of the cases. In conclusion, the pattern-based analysis using the Levenshtein-Damarau distance is both able to predict humanly generated random number sequences and to identify person-specific information within a humanly generated random number sequence.
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Affiliation(s)
- Marc-André Schulz
- Department of Psychiatry and Psychotherapy, RWTH Aachen University, Aachen, Germany
| | | | - Peter Brugger
- Neuropsychology Unit, Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Karsten Witt
- Department of Neurology, Christian Albrecht University, Kiel, Germany
- * E-mail:
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Association between severe dorsolateral prefrontal dysfunction during random number generation and earlier onset in schizophrenia. Clin Neurophysiol 2011; 122:1533-40. [DOI: 10.1016/j.clinph.2010.12.056] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 12/21/2010] [Accepted: 12/23/2010] [Indexed: 11/21/2022]
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30
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Maes JHR, Eling PATM, Reelick MF, Kessels RPC. Assessing executive functioning: on the validity, reliability, and sensitivity of a click/point random number generation task in healthy adults and patients with cognitive decline. J Clin Exp Neuropsychol 2011; 33:366-78. [PMID: 21302171 DOI: 10.1080/13803395.2010.524149] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In random number generation (RNG) tasks, used to assess executive functioning, participants are asked to generate a random sequence of digits at a paced rate, either verbally or by writing. Some previous studies used an alternative format in which participants had to randomly press different response keys, assuming that this task version demands the same cognitive processes as those implied in the standard version. The present study examined the validity of this assumption. To this end, the construct validity, reliability, and sensitivity of a conceptually similar task version of the key-press task were examined. Participants had to randomly click on, or point to, the digits 1-9, laid out orderly in a 3 × 3 grid on a computer screen. Psychometric properties of this task were examined, based on the performance of 131 healthy participants and 80 patients with cognitive decline. The results suggest that the click/point RNG task version can be used as a reliable and valid substitute for standard task versions that use the same response set and response pacing rate as those used in the present study. This task might be a useful alternative, demanding no separate recording and recoding of responses, and being suitable for use with patients with speech or writing problems.
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Affiliation(s)
- Joseph H R Maes
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.
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31
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Abstract
Impairments in executive cognition (EC) may be predictive of incident dementia in patients with mild cognitive impairment (MCI). The present study examined whether specific EC tests could predict which MCI individuals progress from a Clinical Dementia Rating (CDR) score of 0.5 to a score ≥1 over a 2-year period. Eighteen clinical and experimental EC measures were administered at baseline to 104 MCI patients (amnestic and non-amnestic, single- and multiple-domain) recruited from clinical and research settings. Demographic characteristics, screening cognitive measures and measures of everyday functioning at baseline were also considered as potential predictors. Over the 2-year period, 18% of the MCI individuals progressed to CDR ≥ 1, 73.1% remained stable (CDR = 0.5), and 4.5% reverted to normal (CDR = 0). Multiple-domain MCI participants had higher rates of progression to dementia than single-domain, but amnestic and non-amnestic MCIs had similar rates of conversion. Only three EC measures were predictive of subsequent cognitive and functional decline at the univariate level, but they failed to independently predict progression to dementia after adjusting for demographic, other cognitive characteristics, and measures of everyday functioning. Decline over 2 years was best predicted by informant ratings of subtle functional impairments and lower baseline scores on memory, category fluency, and constructional praxis.
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Chan KKS, Hui CLM, Tang JYM, Chiu CPY, Chan SKW, Lam MML, Chen EYH. Random Number Generation Deficit in Early Schizophrenia. Percept Mot Skills 2011; 112:91-103. [DOI: 10.2466/02.15.19.22.pms.112.1.91-103] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Random number generation with a written response mode provides a potentially appealing marker for executive processes. Impaired performance on written random number generation tasks has been reported in chronic schizophrenic patients. However, no study has investigated whether such a deficit occurs in early schizophrenia and whether its profile and severity are similar to those in patients with chronic illness. This study investigated the ability to generate random numbers in patients with early schizophrenia ( n = 44) and a healthy control group ( n = 48). Patients were less able to maintain several production strategies and generated more stereotyped response sequences, whereas their abilities to identify randomness with an even-handed treatment of digits and to monitor the equality of occurrence of single digits appeared to remain intact. These results provide evidence that some aspects of the deficits in random number generation among chronic schizophrenic patients are also present at early psychotic episode, while some other aspects are relatively less affected in the early years.
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33
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Strenge H, Rogge C. Strategic Use of Number Representation is Independent of Test Instruction in Random Number Generation. Percept Mot Skills 2010; 110:453-62. [DOI: 10.2466/pms.110.2.453-462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effects of different instructions on verbal random number generation were examined in 40 healthy students who attempted to generate random sequences of the digits 1 to 6. Two groups of 20 received different instructions with alternative numerical representations. The Symbolic group (Arabic digits) was instructed to randomize while continuously using the analogy of selecting and replacing numbered balls from a hat, whereas the Nonsymbolic group (arrays of dots) was instructed to imagine repeatedly throwing a die. Participants asked for self-reports on their strategies reported spontaneously occurring visuospatial imagination of a mental number line (42%), or imagining throwing a die (23%). Individual number representation was not affected by the initial instruction. There were no differences in randomization performance by group. Comprehensive understanding of the nature of the randomization task requires considering individual differences in construction of mental models.
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Affiliation(s)
- Hans Strenge
- Institute of Medical Psychology and Sociology, University Clinic Schleswig-Holstein, Campus Kiel, Germany
| | - Carolin Rogge
- Institute of Medical Psychology and Sociology, University Clinic Schleswig-Holstein, Campus Kiel, Germany
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34
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Heuer H, Janczyk M, Kunde W. Random noun generation in younger and older adults. Q J Exp Psychol (Hove) 2010; 63:465-78. [DOI: 10.1080/17470210902974138] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We examined age-related changes of executive functions by means of random noun generation. Consistent with previous observations on random letter generation, older participants produced more prepotent responses than younger ones. In the case of random noun generation, prepotent responses are nouns of the same category as the preceding noun. In contrast to previous observations, older participants exhibited stronger repetition avoidance and a stronger tendency toward local evenness—that is, toward equal frequencies of the alternative responses even in short subsequences. These data suggest that at higher adult age inhibition of prepotent responses is impaired. In addition, strategic attentional processes of response selection are strengthened, in particular the application of a heuristic for randomness. In this sense response selection is more controlled in older than in younger adults.
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Affiliation(s)
- Herbert Heuer
- IfADo–Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
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35
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Aretouli E, Brandt J. Everyday functioning in mild cognitive impairment and its relationship with executive cognition. Int J Geriatr Psychiatry 2010; 25:224-33. [PMID: 19650160 PMCID: PMC2987652 DOI: 10.1002/gps.2325] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Elderly persons with mild cognitive impairment (MCI) are at increased risk of dementia and functional impairments. The present study investigated the contribution of three domains of executive cognition to everyday functioning among persons with MCI. METHODS 124 MCI patients and 68 cognitively normal elderly participants were administered a cognitive screening battery. These tests were used to divide patients into four subgroups (amnestic single domain, amnestic multiple domain, non-amnestic single domain, and non-amnestic multiple domain). Subjects were then administered 18 executive function tests that assess planning/problem-solving, working memory, and judgment. Performance of everyday activities and everyday cognition was rated with two informant-reported measures. RESULTS All MCI subtypes had more difficulties in everyday activities than cognitively normal elderly participants. Multiple domain MCI patients had more functional impairments than single domain MCI patients. Contrary to our expectations, only one executive function component, working memory, contributed significantly to functional status after controlling for demographic, health-related and other cognitive factors. CONCLUSIONS Functional abilities are compromised in all MCI subtypes. Working memory may be associated with functional impairments, but general cognitive measures account for more unique variance.
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Affiliation(s)
- Eleni Aretouli
- Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jason Brandt
- Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA,Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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36
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Baldwin S, Farias ST. Neuropsychological assessment in the diagnosis of Alzheimer's disease. ACTA ACUST UNITED AC 2010; Chapter 10:Unit10.3. [PMID: 19802814 DOI: 10.1002/0471142301.ns1003s49] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia in older adults. It represents a significant public health concern because of its associated personal, social, and economic burden. As such, AD is the focus of considerable research worldwide. This unit reviews the major cognitive and behavioral impairments associated with AD, and the practical application of current neuropsychological procedures used to assess these deficits.
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Affiliation(s)
- Sharelle Baldwin
- University of California Davis Health System, Department of Neurology, Sacramento, California, USA
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37
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Response selection in dual task paradigms: observations from random generation tasks. Exp Brain Res 2009; 201:535-48. [DOI: 10.1007/s00221-009-2068-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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38
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Espinosa A, Alegret M, Boada M, Vinyes G, Valero S, Martínez-Lage P, Peña-Casanova J, Becker JT, Wilson BA, Tárraga L. Ecological assessment of executive functions in mild cognitive impairment and mild Alzheimer's disease. J Int Neuropsychol Soc 2009; 15:751-7. [PMID: 19570310 PMCID: PMC2744431 DOI: 10.1017/s135561770999035x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Although memory deficits are typically the earliest and most profound symptoms of Alzheimer's disease (AD) and mild cognitive impairment (MCI), there is increasing recognition of subtle executive dysfunctions in these patients. The purpose of the present study was to determine the sensitivity of the Behavioral Assessment of the Dysexecutive Syndrome (BADS), and to detect early specific signs of the dysexecutive syndrome in the transition from normal cognition to dementia. The BADS was administered to 50 MCI subjects, 50 mild AD patients, and 50 normal controls. Statistically significant differences were found among the three groups with the AD patients performing most poorly, and the MCI subjects performing between controls and AD patients. The Rule Shift Cards and the Action Program subtests were the most highly discriminative between MCI and controls; the Zoo Map and Modified Six Elements between MCI and AD; and the Action Program, Zoo Map, and Modified Six Elements between AD and controls. These results demonstrate that the BADS is clinically useful in discriminating between normal cognition and progressive neurodegenerative conditions. Furthermore, these data confirm the presence of a dysexecutive syndrome even in mildly impaired elderly subjects.
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Affiliation(s)
- Ana Espinosa
- Fundació ACE, Institut Català de Neurociències Aplicades, Barcelona, Spain
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39
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Brandt J, Aretouli E, Neijstrom E, Samek J, Manning K, Albert MS, Bandeen-Roche K. Selectivity of executive function deficits in mild cognitive impairment. Neuropsychology 2009; 23:607-18. [PMID: 19702414 PMCID: PMC2769993 DOI: 10.1037/a0015851] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Impairment in executive cognition (EC) is now recognized as relatively common among older persons with mild cognitive impairment (MCI) and may be predictive of the development of dementia. However, both MCI and executive functioning are broad and heterogeneous constructs. The present study sought to determine whether impairments in specific domains of EC are associated with specific subtypes of MCI. MCI patients (n = 124) were divided into 4 subgroups (amnestic vs. nonamnestic, and single- vs. multiple-domain) on the basis of their performance of widely used neuropsychological screening tests. These patients and 68 normal older persons were administered 18 clinical and experimental tests of executive function. Principal components analysis suggested 2 highly reliable EC components, planning/problem solving and working memory, and a less reliable 3rd component, judgment. Planning/problem solving and working memory, but not judgment, were impaired among the MCI patients. This was true even among those with "pure amnestic" MCI, the least impaired group overall. Multiple-domain MCI patients had more severe impairments in planning/problem solving and working memory than single-domain patients, leading to the supposition that they, not pure amnestic MCIs, are at highest risk of imminent dementia.
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Affiliation(s)
- Jason Brandt
- Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, 21287-7218, USA.
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40
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Strenge H, Lesmana CBJ, Suryani LK. Random Number Generation in Bilingual Balinese and German Students: Preliminary Findings from an Exploratory Cross-Cultural Study. Percept Mot Skills 2009; 109:61-75. [DOI: 10.2466/pms.109.1.61-75] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Verbal random number generation is a procedurally simple task to assess executive function and appears ideally suited for the use under diverse settings in cross-cultural research. The objective of this study was to examine ethnic group differences between young adults in Bali (Indonesia) and Kiel (Germany). 50 bilingual healthy students, 30 Balinese and 20 Germans, attempted to generate a random sequence of the digits 1 to 9. In Balinese participants, randomization was done in Balinese (native language L1) and Indonesian (first foreign language L2), in German subjects in the German (L1) and English (L2) languages. 10 of 30 Balinese (33%), but no Germans, were unable to inhibit habitual counting in more than half of the responses. The Balinese produced significantly more nonrandom responses than the Germans with higher rates of counting and significantly less occurrence of the digits 2 and 3 in L1 compared with L2. Repetition and cycling behavior did not differ between the four languages. The findings highlight the importance of taking into account culture-bound psychosocial factors for Balinese individuals when administering and interpreting a random number generation test.
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Affiliation(s)
- Hans Strenge
- Institute of Medical Psychology and Sociology, University Clinic Schleswig-Holstein, Campus Kiel, Germany
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41
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Peters MJV, Jelicic M, Haas N, Merckelbach H. MILD EXECUTIVE DYSFUNCTIONS IN UNDERGRADUATES ARE RELATED TO RECOLLECTING WORDS NEVER PRESENTED. Int J Neurosci 2009; 116:1065-77. [PMID: 16861169 DOI: 10.1080/00207450600808768] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The aim of this study was to explore whether individual differences in executive function in undergraduate students (n = 72) contribute to false recall and recognition as obtained with the Deese/Roediger-McDermott (DRM) paradigm. Participants were subjected to the DRM paradigm and also were given a test designed to assess executive function--the Random Number Generation task (RNG). A relationship was found between heightened seriation on the RNG (indicating a deficiency in the ability to inhibit cognitive schemes) and false recognition of non-presented, critical lure words in the DRM paradigm. This suggests that individual differences in executive function do occur in a healthy population and that the reconstructive activity inherent in memory depends in part on executive functioning.
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Affiliation(s)
- Maarten J V Peters
- Maastricht University, Faculty of Psychology Department of Experimental Psychology, Maastricht, The Netherlands.
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42
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Loetscher T, Brugger P. Random number generation in neglect patients reveals enhanced response stereotypy, but no neglect in number space. Neuropsychologia 2009; 47:276-9. [PMID: 18771676 DOI: 10.1016/j.neuropsychologia.2008.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 07/19/2008] [Accepted: 08/06/2008] [Indexed: 10/21/2022]
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43
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Abstract
How to estimate the randomness in random sequence generation tasks?
The aim of the paper was to discuss the accuracy of the multiple indexes used for random sequences generation results calculation. In the first part of the paper the models explaining deviations from randomness were presented. The key role of the structural limitations interpretation was suggested. Secondly, the multiple indexes of the deviation from randomness used in random sequence generation task studies were presented. The authors concluded that too many indexes are used in the studies of deviation from randomness. In order to avoid such problems two indexes were proposed: entropy and correlation function. The last part of the paper presents the preliminary version of the mathematical of random sequences generation in which the limited capacity of the short-term memory assumption was introduce.
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44
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Figurska M, Stańczyk M, Kulesza K. Humans cannot consciously generate random numbers sequences: Polemic study. Med Hypotheses 2007; 70:182-5. [PMID: 17888582 DOI: 10.1016/j.mehy.2007.06.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 06/30/2007] [Indexed: 11/29/2022]
Abstract
It is widely believed, that randomness exists in Nature. In fact such an assumption underlies many scientific theories and is embedded in the foundations of quantum mechanics. Assuming that this hypothesis is valid one can use natural phenomena, like radioactive decay, to generate random numbers. Today, computers are capable of generating the so-called pseudorandom numbers. Such series of numbers are only seemingly random (bias in the randomness quality can be observed). Question whether people can produce random numbers, has been investigated by many scientists in the recent years. The paper "Humans can consciously generate random numbers sequences..." published recently in Medical Hypotheses made claims that were in many ways contrary to state of art; it also stated far-reaching hypotheses. So, we decided to repeat the experiments reported, with special care being taken of proper laboratory procedures. Here, we present the results and discuss possible implications in computer and other sciences.
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Affiliation(s)
- Małgorzata Figurska
- Institute of Fundamental Technological Research, Polish Academy of Sciences, ul. Swietokrzyska 21, 00-049 Warsaw, Poland.
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45
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Strenge H, Müller-Deile J. Auditory feedback does not influence random number generation: Evidence from profoundly deaf adults with cochlear implant. J Clin Exp Neuropsychol 2007; 29:642-7. [PMID: 17691037 DOI: 10.1080/13803390600899873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Oral random number generation is a widely used neuropsychological task engaging a number of overlapping neural systems of attention, number representation, response generation, and working memory. Although phonological processing is known to be essential for random number generation no information exists on the significance of the auditory feedback of hearing one's own voice on task performance. We therefore examined the influence of auditory feedback in 15 profoundly deaf adults with cochlear implants in a device-on/off experiment. No significant effects of occluding auditory feedback on random number generation were noted, thus supporting an internal response-monitoring model independent of auditory condition.
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Affiliation(s)
- Hans Strenge
- Institute of Medical Psychology, University Clinic Schleswig-Holstein, Campus Kiel, Germany.
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46
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Peters M, Giesbrecht T, Jelicic M, Merckelbach H. The random number generation task: psychometric properties and normative data of an executive function task in a mixed sample. J Int Neuropsychol Soc 2007; 13:626-34. [PMID: 17521494 DOI: 10.1017/s1355617707070786] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 02/02/2007] [Accepted: 02/02/2007] [Indexed: 11/07/2022]
Abstract
We investigated the psychometric properties of the random number generation (RNG) task in four studies using a mixed sample of young adults (n = 306), middle-aged adults (n = 40), and patients diagnosed with schizophrenia (n = 26). Data in study 1 were best accounted for by a three-factor solution representing inhibition of stereotypical schemas (seriation), output inhibition (repetition), and monitoring of previous output (cycling). Modest test-retest correlations were found, with the seriation factor showing acceptable stability across time (study 2). In study 3, RNG task performance was related to scores on concurrent neurocognitive tasks to establish construct validity. RNG scores correlated with healthy controls' performance on the Stroop color-word test and patients diagnosed with schizophrenia with executive dysfunctions. Patients diagnosed with schizophrenia performed poorer on the seriation factor of the RNG than healthy control participants (study 4). Our results indicate that the RNG task has modest to acceptable psychometric properties. It primarily taps executive subfunctions (i.e., inhibition, updating, and monitoring), which are affected by psychopathological or neurological deficits.
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Affiliation(s)
- Maarten Peters
- Department of Experimental Psychology, Maastricht University, Maastricht, The Netherlands.
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47
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48
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Brugger P, Loetscher T, Graves RE, Knoch D. Semantic, perceptual and number space: Relations between category width and spatial processing. Neurosci Lett 2007; 418:133-7. [PMID: 17400383 DOI: 10.1016/j.neulet.2007.03.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 03/06/2007] [Accepted: 03/07/2007] [Indexed: 10/23/2022]
Abstract
Coarse semantic encoding and broad categorization behavior are the hallmarks of the right cerebral hemisphere's contribution to language processing. We correlated 40 healthy subjects' breadth of categorization as assessed with Pettigrew's category width scale with lateral asymmetries in perceptual and representational space. Specifically, we hypothesized broader category width to be associated with larger leftward spatial biases. For the 20 men, but not the 20 women, this hypothesis was confirmed both in a lateralized tachistoscopic task with chimeric faces and a random digit generation task; the higher a male participant's score on category width, the more pronounced were his left-visual field bias in the judgement of chimeric faces and his small-number preference in digit generation ("small" is to the left of "large" in number space). Subjects' category width was unrelated to lateral displacements in a blindfolded tactile-motor rod centering task. These findings indicate that visual-spatial functions of the right hemisphere should not be considered independent of the same hemisphere's contribution to language. Linguistic and spatial cognition may be more tightly interwoven than is currently assumed.
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Affiliation(s)
- Peter Brugger
- Department of Neurology, University Hospital Zurich, Switzerland.
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49
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Loetscher T, Brugger P. Exploring number space by random digit generation. Exp Brain Res 2007; 180:655-65. [PMID: 17294177 DOI: 10.1007/s00221-007-0889-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 01/16/2007] [Indexed: 10/23/2022]
Abstract
There is some evidence that human subjects preferentially select small numbers when asked to sample numbers from large intervals "at random". A retrospective analysis of single digit frequencies in 16 independent experiments with the Mental Dice Task (generation of digits 1-6 during 1 min) confirmed the occurrence of small-number biases (SNBs) in 488 healthy subjects. A subset of these experiments suggested a spatial nature of this bias in the sense of a "leftward" shift along the number line. First, individual SNBs were correlated with leftward deviations in a number line bisection task (but unrelated to the bisection of physical lines). Second, in 20 men, the magnitude of SNBs significantly correlated with leftward attentional biases in the judgment of chimeric faces. Finally, cognitive activation of the right hemisphere enhanced SNBs in 20 different men, while left hemisphere activation reduced them. Together, these findings provide support for a spatial component in random number generation. Specifically, they allow an interpretation of SNBs in terms of "pseudoneglect in number space." We recommend the use of random digit generation for future explorations of spatial-attentional asymmetries in numerical processing and discuss methodological issues relevant to prospective designs.
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Affiliation(s)
- Tobias Loetscher
- Neuropsychology Unit, Department of Neurology, University Hospital Zurich, 8091 Zurich, Switzerland.
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50
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Allain P, Chaudet H, Nicoleau S, Etcharry-Bouyx F, Barré J, Dubas F, Berrut G, Le Gall D. Étude de la planification de l’action au moyen du test du plan du zoo dans la maladie d’Alzheimer. Rev Neurol (Paris) 2007; 163:222-30. [PMID: 17351541 DOI: 10.1016/s0035-3787(07)90393-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Executive dysfunction is regularly reported in patients with Alzheimer's disease. Nevertheless few studies have focused on planning ability in this neurodegenerative disease. OBJECTIVES This study aimed to investigate the formulation and the execution of plans in Alzheimer's disease using an ecological planning subtask derived from the Behavioural Assessment of the Dysexecutive Syndrome test battery, the "Zoo Map Test". There are two trials. The first trial consists of a "high demand" version of the subtask in which the subjects must plan in advance the order in which they will visit designated locations in a zoo (formulation level). In the second, or "low demand" version, the subject is simply required to follow a concrete externally imposed strategy to reach the locations to visit (execution level). The test was given to 16 patients with Alzheimer's disease and 13 normal elderly subjects. RESULTS The two way ANOVAs mainly showed more difficulties in patients with Alzheimer's disease than in healthy elderly in both conditions. The difference between formulation and execution was greater in patients with Alzheimer's disease than in healthy elderly. Planning impairments mainly correlated with behavioural changes (in particular motivational changes) observed by patient's relatives. CONCLUSION These results suggest that patients with Alzheimer's disease have some problems to mentally develop logical strategies and to execute complex predetermined plans, which are partially related to behavioural changes.
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Affiliation(s)
- P Allain
- Centre Mémoire de Ressources et de Recherche, CHU Angers.
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