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1.
Eur Addict Res ; 28(4): 255-266, 2022.
Article de Anglais | MEDLINE | ID: mdl-35124666

RÉSUMÉ

INTRODUCTION: Smartphones are often helpful in our everyday lives. Yet, they also tend to interrupt us during other activities. It has been argued that such distractions contribute to attention-deficit/hyperactivity disorder-like symptoms. However, since there are mostly correlational studies, the causal nature of this relationship is unclear. Our aim was to test whether reducing smartphone-related distractions might have a beneficial effect on inattention and hyperactive symptoms. METHODS: We conducted a 1-week field experiment with 37 healthy undergraduates and quasi-randomly assigned them to an intervention or control group (CG). The intervention group was given theory-based specific instructions that aimed at reducing smartphone-related distractions, whereas the CG received no intervention. The outcomes of interest were inattention level, hyperactive symptoms, and working memory accuracy. RESULTS: Compared to those in the control condition, participants who limited their smartphone use showed considerable reductions in hyperactive symptoms after 1 week - particularly those who displayed high problematic smartphone use. However, there were no group differences regarding inattention symptoms and working memory accuracy. DISCUSSION: The results give a first hint that strategically reducing smartphone-related distractions via specific but simple use modifications can mitigate hyperactive symptoms. Especially people with problematic smartphone use seem to profit from such an intervention. Remaining questions and directions are discussed.


Sujet(s)
Trouble déficitaire de l'attention avec hyperactivité , Ordiphone , Trouble déficitaire de l'attention avec hyperactivité/diagnostic , Cognition , Humains
2.
Eur Arch Psychiatry Clin Neurosci ; 272(6): 1119-1134, 2022 Sep.
Article de Anglais | MEDLINE | ID: mdl-34275007

RÉSUMÉ

The self-concept-defined as the cognitive representation of beliefs about oneself-determines how individuals view themselves, others, and their actions. A negative self-concept can drive gaming use and internet gaming disorder (IGD). The assessment of the neural correlates of self-evaluation gained popularity to assess the self-concept in individuals with IGD. This attempt, however, seems to critically depend on the reliability of the investigated task-fMRI brain activation. As first study to date, we assessed test-retest reliability of an fMRI self-evaluation task. Test-retest reliability of neural brain activation between two separate fMRI sessions (approximately 12 months apart) was investigated in N = 29 healthy participants and N = 11 individuals with pathological internet gaming. We computed reliability estimates for the different task contrasts (self, a familiar, and an unknown person) and the contrast (self > familiar and unknown person). Data indicated good test-retest reliability of brain activation, captured by the "self", "familiar person", and "unknown person" contrasts, in a large network of brain regions in the whole sample (N = 40) and when considering both experimental groups separately. In contrast to that, only a small set of brain regions showed moderate to good reliability, when investigating the contrasts ("self > familiar and unknown person"). The lower reliability of the contrast can be attributed to the fact that the constituting contrast conditions were highly correlated. Future research on self-evaluation should be cautioned by the findings of substantial local reliability differences across the brain and employ methods to overcome these limitations.


Sujet(s)
Comportement toxicomaniaque , Jeux vidéo , Humains , Comportement toxicomaniaque/imagerie diagnostique , Encéphale/imagerie diagnostique , Cartographie cérébrale , Auto-évaluation diagnostique , Internet , Dépendance à Internet , Imagerie par résonance magnétique/méthodes , Reproductibilité des résultats , Jeux vidéo/psychologie
3.
Sleep ; 45(2)2022 02 14.
Article de Anglais | MEDLINE | ID: mdl-34932818

RÉSUMÉ

STUDY OBJECTIVES: Subjective reports of sleep impairments are common in individuals with posttraumatic stress disorder (PTSD), but objective assessments of sleep have yielded mixed results. METHODS: We investigated sleep via actigraphy and e-diary on 6 consecutive nights in a group of 117 women with PTSD after childhood abuse (CA; PTSD group), a group of 31 mentally healthy women with a history of CA (healthy trauma controls, HTC group) and a group of 36 nontraumatized mentally healthy women (healthy controls, HC group). RESULTS: The PTSD group reported lower sleep quality, more nights with nightmares, and shorter sleep duration than both HTC and HC. Actigraphic measures showed more and longer sleep interruptions in the PTSD group compared to HTC and HC, but no difference in sleep duration. While the PTSD group underestimated their sleep duration, both HTC and HC overestimated their sleep duration. HTC did not differ from HC regarding sleep impairments. CONCLUSIONS: Sleep in women with PTSD after CA seems to be more fragmented but not shorter compared to sleep patterns of mentally healthy control subjects. The results suggest a stronger effect of PTSD psychopathology on sleep compared to the effect of trauma per se. SUBSET OF DATA FROM CLINICAL TRIAL: Treating Psychosocial and Neural Consequences of Childhood Interpersonal Violence in Adults (RELEASE), https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00000000, German Clinical Trials registration number: DRKS00005578.


Sujet(s)
Adultes victimes de maltraitance dans l'enfance , Sommeil , Troubles de stress post-traumatique , Actigraphie , Adulte , Adultes victimes de maltraitance dans l'enfance/psychologie , Adultes victimes de maltraitance dans l'enfance/statistiques et données numériques , Études cas-témoins , Rêves , Femelle , Humains , Troubles de la veille et du sommeil/épidémiologie , Troubles de stress post-traumatique/psychologie , Facteurs temps
4.
Epilepsia Open ; 6(3): 597-606, 2021 09.
Article de Anglais | MEDLINE | ID: mdl-34250754

RÉSUMÉ

OBJECTIVE: To identify non-EEG-based signals and algorithms for detection of motor and non-motor seizures in people lying in bed during video-EEG (VEEG) monitoring and to test whether these algorithms work in freely moving people during mobile EEG recordings. METHODS: Data of three groups of adult people with epilepsy (PwE) were analyzed. Group 1 underwent VEEG with additional devices (accelerometry, ECG, electrodermal activity); group 2 underwent VEEG; and group 3 underwent mobile EEG recordings both including one-lead ECG. All seizure types were analyzed. Feature extraction and machine-learning techniques were applied to develop seizure detection algorithms. Performance was expressed as sensitivity, precision, F1 score, and false positives per 24 hours. RESULTS: The algorithms were developed in group 1 (35 PwE, 33 seizures) and achieved best results (F1 score 56%, sensitivity 67%, precision 45%, false positives 0.7/24 hours) when ECG features alone were used, with no improvement by including accelerometry and electrodermal activity. In group 2 (97 PwE, 255 seizures), this ECG-based algorithm largely achieved the same performance (F1 score 51%, sensitivity 39%, precision 73%, false positives 0.4/24 hours). In group 3 (30 PwE, 51 seizures), the same ECG-based algorithm failed to meet up with the performance in groups 1 and 2 (F1 score 27%, sensitivity 31%, precision 23%, false positives 1.2/24 hours). ECG-based algorithms were also separately trained on data of groups 2 and 3 and tested on the data of the other groups, yielding maximal F1 scores between 8% and 26%. SIGNIFICANCE: Our results suggest that algorithms based on ECG features alone can provide clinically meaningful performance for automatic detection of all seizure types. Our study also underscores that the circumstances under which such algorithms were developed, and the selection of the training and test data sets need to be considered and limit the application of such systems to unseen patient groups behaving in different conditions.


Sujet(s)
Épilepsie , Crises épileptiques , Adulte , Algorithmes , Électrocardiographie , Électroencéphalographie/méthodes , Épilepsie/diagnostic , Humains , Crises épileptiques/diagnostic
5.
Int J Bipolar Disord ; 8(1): 35, 2020 Nov 17.
Article de Anglais | MEDLINE | ID: mdl-33211262

RÉSUMÉ

BACKGROUND: Digital phenotyping promises to unobtrusively obtaining a continuous and objective input of symptomatology from patients' daily lives. The prime example are bipolar disorders, as smartphone parameters directly reflect bipolar symptomatology. Empirical studies, however, have yielded inconsistent findings. We believe that three main shortcomings have to be addressed to fully leverage the potential of digital phenotyping: short assessment periods, rare outcome assessments, and an extreme fragmentation of parameters without an integrative analytical strategy. METHODS: To demonstrate how to overcome these shortcomings, we conducted frequent (biweekly) dimensional and categorical expert ratings and daily self-ratings over an extensive assessment period (12 months) in 29 patients with bipolar disorder. Digital phenotypes were monitored continuously. As an integrative analytical strategy, we used structural equation modelling to build latent psychopathological outcomes (mania, depression) and latent digital phenotype predictors (sleep, activity, communicativeness). OUTCOMES: Combining gold-standard categorical expert ratings with dimensional self and expert ratings resulted in two latent outcomes (mania and depression) with statistically meaningful factor loadings that dynamically varied over 299 days. Latent digital phenotypes of sleep and activity were associated with same-day latent manic psychopathology, suggesting that psychopathological alterations in bipolar disorders relate to domains (latent variables of sleep and activity) and not only to specific behaviors (such as the number of declined incoming calls). The identification of latent psychopathological outcomes that dimensionally vary on a daily basis will enable to empirically determine which combination of digital phenotypes at which days prior to an upcoming episode are viable as digital prodromal predictors.

6.
Sensors (Basel) ; 20(19)2020 Oct 01.
Article de Anglais | MEDLINE | ID: mdl-33019577

RÉSUMÉ

Measuring brain activity in moving subjects is of great importance for investigating human behavior in ecological settings. For this purpose, EEG measures are applicable; however, technical modifications are required to reduce the typical massive movement artefacts. Four different approaches to measure EEG/ERPs during rowing were tested: (i) a purpose-built head-mounted preamplifier, (ii) a laboratory system with active electrodes, and a wireless headset combined with (iii) passive or (iv) active electrodes. A standard visual oddball task revealed very similar (within subjects) visual evoked potentials for rowing and rest (without movement). The small intraindividual differences between rowing and rest, in comparison to the typically larger interindividual differences in the ERP waveforms, revealed that ERPs can be measured reliably even in an athletic movement such as rowing. On the other hand, the expected modulation of the motor-related activity by force output was largely affected by movement artefacts. Therefore, for a successful application of ERP measures in movement research, further developments to differentiate between movement-related neuronal activity and movement-related artefacts are required. However, activities with small magnitudes related to motor learning and motor control may be difficult to detect because they are superimposed by the very large motor potential, which increases with force output.


Sujet(s)
Ergométrie/méthodes , Potentiels évoqués visuels , Sports nautiques , Électroencéphalographie , Humains , Projets pilotes
7.
Psychol Sport Exerc ; 502020 Sep.
Article de Anglais | MEDLINE | ID: mdl-32831643

RÉSUMÉ

Technological and digital progress benefits physical activity (PA) research. Here we compiled expert knowledge on how Ambulatory Assessment (AA) is utilized to advance PA research, i.e., we present results of the 2nd International CAPA Workshop 2019 "Physical Activity Assessment - State of the Science, Best Practices, Future Directions" where invited researchers with experience in PA assessment, evaluation, technology and application participated. First, we provide readers with the state of the AA science, then we give best practice recommendations on how to measure PA via AA and shed light on methodological frontiers, and we furthermore discuss future directions. AA encompasses a class of methods that allows the study of PA and its behavioral, biological and physiological correlates as they unfold in everyday life. AA includes monitoring of movement (e.g., via accelerometry), physiological function (e.g., via mobile electrocardiogram), contextual information (e.g., via geolocation-tracking), and ecological momentary assessment (EMA; e.g., electronic diaries) to capture self-reported information. The strengths of AA are data assessment that near realtime, which minimizes retrospective biases in real-world settings, consequentially enabling ecological valid findings. Importantly, AA enables multiple assessments across time within subjects resulting in intensive longitudinal data (ILD), which allows unraveling within-person determinants of PA in everyday life. In this paper, we show how AA methods such as triggered e-diaries and geolocation-tracking can be used to measure PA and its correlates, and furthermore how these findings may translate into real-life interventions. In sum, AA provides numerous possibilities for PA research, especially the opportunity to tackle within- subject antecedents, concomitants, and consequences of PA as they unfold in everyday life. In-depth insights on determinants of PA could help us design and deliver impactful interventions in real-world contexts, thus enabling us to solve critical health issues in the 21st century such as insufficient PA and high levels of sedentary behavior.

8.
PLoS One ; 15(5): e0232666, 2020.
Article de Anglais | MEDLINE | ID: mdl-32392213

RÉSUMÉ

Early experiences of childhood sexual or physical abuse are often associated with functional impairments, reduced well-being and interpersonal problems in adulthood. Prior studies have addressed whether the traumatic experience itself or adult psychopathology is linked to these limitations. To approach this question, individuals with posttraumatic stress disorder (PTSD) and healthy individuals with and without a history of child abuse were investigated. We used global positioning system (GPS) tracking to study temporal and spatial limitations in the participants' real-life activity space over the course of one week. The sample consisted of 228 female participants: 150 women with PTSD and emotional instability with a history of child abuse, 35 mentally healthy women with a history of child abuse (healthy trauma controls, HTC) and 43 mentally healthy women without any traumatic experiences in their past (healthy controls, HC). Both traumatized groups-i.e. the PTSD and the HTC group-had smaller movement radii than the HC group on the weekends, but neither spent significantly less time away from home than HC. Some differences between PTSD and HC in movement radius seem to be related to correlates of PTSD psychopathology, like depression and physical health. Yet group differences between HTC and HC in movement radius remained even when contextual and individual health variables were included in the model, indicating specific effects of traumatic experiences on activity space. Experiences of child abuse could limit activity space later in life, regardless of whether PTSD develops.


Sujet(s)
Maltraitance des enfants/psychologie , Troubles de stress post-traumatique/psychologie , Adulte , Adultes victimes de maltraitance dans l'enfance/psychologie , Enfant , Dépression/psychologie , Femelle , Systèmes d'information géographique , Humains , Mode de vie , Adulte d'âge moyen , Jeune adulte
9.
Addict Biol ; 25(1): e12712, 2020 01.
Article de Anglais | MEDLINE | ID: mdl-30672054

RÉSUMÉ

Research in memory reconsolidation has raised hope for new treatment options of persistent psychiatric disorders like substance dependence and post-traumatic stress disorder (PTSD). While animal research showed successful memory modification by interfering with reconsolidation, human research requires less invasive techniques. In our pilot study, we aimed to reduce appetitive memory reconsolidation of a newly acquired reward memory by exerting a stressor. Thirty healthy participants were randomly assigned to two groups performing a monetary reward paradigm at a personal computer. Day 1 was considered to allow for memory acquisition; on day 2, the experimental group was exposed to a frightening stimulus in the reconsolidation window; and day 3 again served to determine reward memory effects. Measures of reward memory were reaction times to reward announcing stimuli (ie, showing instrumental behavior), actual reward gained, and electrodermal response as a measure for reward anticipation. We found significantly smaller reaction time improvements to reward stimuli over time in the experimental group, as well as reduced achievements in monetary reward. Electrodermal response to reward announcing stimuli was lower in the experimental group after intervention, whereas it was higher in the untreated group. Thus, we argue in favor of the reconsolidation hypothesis, assuming our intervention had successfully interfered with the reconsolidation process. This points towards future treatment options that interfere with an addiction memory.


Sujet(s)
Conditionnement psychologique/physiologie , Mémoire/physiologie , Récompense , Stress psychologique/physiopathologie , Adolescent , Adulte , Électrocardiographie , Peur , Femelle , Réflexe psychogalvanique/physiologie , Humains , Hydrocortisone/métabolisme , Mâle , Adulte d'âge moyen , Projets pilotes , Temps de réaction/physiologie , Salive/métabolisme , Stress psychologique/métabolisme , Jeune adulte
10.
BMC Psychiatry ; 18(1): 349, 2018 10 26.
Article de Anglais | MEDLINE | ID: mdl-30367608

RÉSUMÉ

BACKGROUND: The detection of early warning signs is essential in the long-term treatment of bipolar disorders. However, in bipolar patients' daily life and outpatient treatment the assessment of upcoming state changes faces several difficulties. In this trial, we examine the effectiveness of a smartphone based automated feedback about ambulatory assessed early warning signs in prolonging states of euthymia and therefore preventing hospitalization. This study aims to assess, whether patients experience longer episodes of euthymia, when their treating psychiatrists receive automated feedback about changes in communication and activity. With this additional information an intervention at an earlier stage in the development of mania or depression could be facilitated. We expect that the amount of time will be longer between affective episodes in the intervention group. METHODS/DESIGN: The current study is designed as a randomized, multi-center, observer-blind, active-control, parallel group trial within a nationwide research project on the topic of innovative methods for diagnostics, prevention and interventions of bipolar disorders. One hundred and twenty patients with bipolar disorder will be randomly assigned to (1) the experimental group with included automated feedback or (2) the control group without feedback. During the intervention phase, the psychopathologic state of all participants is assessed every four weeks over 18 months. Kaplan-Meier estimators will be used for estimating the survival functions, a Log-Rank test will be used to formally compare time to a new episode across treatment groups. An intention-to-treat analysis will include data from all randomized patients. DISCUSSION: This article describes the design of a clinical trial investigating the effectiveness of a smartphone-based feedback loop. This feedback loop is meant to elicit early interventions at the detection of warning signs for the prevention of affective episodes in bipolar patients. This approach will hopefully improve the chances of a timely intervention helping patients to keep a balanced mood for longer periods of time. In detail, if our hypothesis can be confirmed, clinical practice treating psychiatrists will be enabled to react quickly when changes are automatically detected. Therefore, outpatients would receive an even more individually tailored treatment concerning time and frequency of doctor's appointments. TRIAL REGISTRATION: ClinicalTrials.gov : NCT02782910 : Title: "Smartphone-based Ambulatory Assessment of Early Warning Signs (BipoLife_A3)". Registered May 25 2016. Protocol Amendment Number: 03. Issue Date: 26 March 2018. Author(s): ES.


Sujet(s)
Soins ambulatoires/méthodes , Trouble bipolaire/diagnostic , Tests psychologiques , Ordiphone , Télémédecine/méthodes , Adulte , Affect , Trouble bipolaire/psychologie , Dépression/diagnostic , Dépression/psychologie , Femelle , Humains , Soins de longue durée , Mâle , Patients en consultation externe/psychologie , Valeur prédictive des tests , Essais contrôlés randomisés comme sujet , Reproductibilité des résultats , Méthode en simple aveugle , Facteurs temps
11.
Schizophr Res Treatment ; 2017: 7163198, 2017.
Article de Anglais | MEDLINE | ID: mdl-28932600

RÉSUMÉ

OBJECTIVE: Activation of semantic networks is indexed by the N400 effect. We used a twin study design to investigate whether N400 effect abnormalities reflect genetic/trait liability or are related to psychopathological processes in schizophrenia. METHODS: We employed robust linear regression to compare N400 and behavioral priming effects across 36 monozygotic twin pairs (6 pairs concordant for schizophrenia/schizoaffective disorder, 11 discordant pairs, and 19 healthy control pairs) performing a lexical decision task. Moreover, we examined the correlation between Brief Psychiatric Rating Scale (BPRS) score and the N400 effect and the influence of medication status on this effect. RESULTS: Regression yielded a significant main effect of group on the N400 effect only in the direct priming condition (p = 0.003). Indirect condition and behavioral priming effect showed no significant effect of group. Planned contrasts with the control group as a reference group revealed that affected concordant twins had significantly reduced N400 effect compared to controls, and discordant affected twins had a statistical trend for reduced N400 effect compared to controls. The unaffected twins did not differ significantly from the controls. There was a trend for correlation between reduced N400 effect and higher BPRS scores, and the N400 effect did not differ significantly between medicated and unmedicated patients. CONCLUSIONS: Reduced N400 effect may reflect disease-specific processes in schizophrenia implicating frontotemporal brain network in schizophrenia pathology.

12.
J Behav Addict ; 5(3): 485-99, 2016 Sep.
Article de Anglais | MEDLINE | ID: mdl-27415603

RÉSUMÉ

Background and aims Internet gaming addiction appears to be related to self-concept deficits and increased angular gyrus (AG)-related identification with one's avatar. For increased social network use, a few existing studies suggest striatal-related positive social feedback as an underlying factor. However, whether an impaired self-concept and its reward-based compensation through the online presentation of an idealized version of the self are related to pathological social network use has not been investigated yet. We aimed to compare different stages of pathological Internet game and social network use to explore the neural basis of avatar and self-identification in addictive use. Methods About 19 pathological Internet gamers, 19 pathological social network users, and 19 healthy controls underwent functional magnetic resonance imaging while completing a self-retrieval paradigm, asking participants to rate the degree to which various self-concept-related characteristics described their self, ideal, and avatar. Self-concept-related characteristics were also psychometrically assessed. Results Psychometric testing indicated that pathological Internet gamers exhibited higher self-concept deficits generally, whereas pathological social network users exhibit deficits in emotion regulation only. We observed left AG hyperactivations in Internet gamers during avatar reflection and a correlation with symptom severity. Striatal hypoactivations during self-reflection (vs. ideal reflection) were observed in social network users and were correlated with symptom severity. Discussion and conclusion Internet gaming addiction appears to be linked to increased identification with one's avatar, evidenced by high left AG activations in pathological Internet gamers. Addiction to social networks seems to be characterized by emotion regulation deficits, reflected by reduced striatal activation during self-reflection compared to during ideal reflection.


Sujet(s)
Comportement toxicomaniaque/physiopathologie , Comportement toxicomaniaque/psychologie , Encéphale/physiopathologie , Concept du soi , Réseautage social , Jeux vidéo/psychologie , Adulte , Cartographie cérébrale , Émotions/physiologie , Femelle , Humains , Imagerie par résonance magnétique , Mâle , Tests neuropsychologiques , Psychométrie , Sang-froid/psychologie
13.
PLoS One ; 10(4): e0124231, 2015.
Article de Anglais | MEDLINE | ID: mdl-25885258

RÉSUMÉ

BACKGROUND: Abnormalities in motor activity represent a central feature in major depressive disorder. However, measurement issues are poorly understood, limiting the use of objective measurement of motor activity for diagnostics and treatment monitoring. METHODS: To improve measurement issues, especially sensor placement, analytic strategies and diurnal effects, we assessed motor activity in depressed patients at the beginning (MD; n=27) and after anti-depressive treatment (MD-post; n=18) as well as in healthy controls (HC; n=16) using wrist- and chest-worn accelerometers. We performed multiple analyses regarding sensor placements, extracted features, diurnal variation, motion patterns and posture to clarify which parameters are most powerful in distinguishing patients from controls and monitoring treatment effects. RESULTS: Whereas most feature-placement combinations revealed significant differences between groups, acceleration (wrist) distinguished MD from HC (d=1.39) best. Frequency (vertical axis chest) additionally differentiated groups in a logistic regression model (R2=0.54). Accordingly, both amplitude (d=1.16) and frequency (d=1.04) showed alterations, indicating reduced and decelerated motor activity. Differences between MD and HC in gestures (d=0.97) and walking (d=1.53) were found by data analysis from the wrist sensor. Comparison of motor activity at the beginning and after MD-treatment largely confirms our findings. LIMITATIONS: Sample size was small, but sufficient for the given effect sizes. Comparison of depressed in-patients with non-hospitalized controls might have limited motor activity differences between groups. CONCLUSIONS: Measurement of wrist-acceleration can be recommended as a basic technique to capture motor activity in depressed patients as it records whole body movement and gestures. Detailed analyses showed differences in amplitude and frequency denoting that depressed patients walked less and slower.


Sujet(s)
Actigraphie/méthodes , Rythme circadien , Trouble dépressif majeur/physiopathologie , Activité motrice , Actigraphie/instrumentation , Adulte , Antidépresseurs/usage thérapeutique , Études cas-témoins , Trouble dépressif majeur/traitement médicamenteux , Surveillance des médicaments/instrumentation , Surveillance des médicaments/méthodes , Femelle , Gestes , Hospitalisation , Humains , Modèles logistiques , Mâle , Adulte d'âge moyen , Activité motrice/effets des médicaments et des substances chimiques , Spécificité d'organe , Posture , Thorax , Marche à pied , Poignet , Jeune adulte
14.
J Sports Sci ; 33(15): 1637-8, 2015.
Article de Anglais | MEDLINE | ID: mdl-25599117

RÉSUMÉ

In a case study, Schaffert and Mattes reported the application of acoustic feedback (sonification) to optimise the time course of boat acceleration. The authors attributed an increased boat speed in the feedback condition to an optimised boat acceleration (mainly during the recovery phase). However, in rowing it is biomechanically impossible to increase the boat speed significantly by reducing the fluctuations in boat acceleration during the rowing cycle. To assess such a, potentially small, optimising effect experimentally, the confounding variables must be controlled very accurately (that is especially the propulsive forces must be kept constant between experimental conditions or the differences in propulsive forces between conditions must be much smaller than the effects on boat speed resulting from an optimised movement pattern). However, this was not controlled adequately by the authors. Instead, the presented boat acceleration data show that the increased boat speed under acoustic feedback was due to increased propulsive forces.


Sujet(s)
Acoustique , Performance sportive/physiologie , Rétroaction sensorielle , Éducation physique et entraînement physique/méthodes , Sports/physiologie , Personnes malvoyantes , Femelle , Humains , Mâle
15.
Behav Neurosci ; 129(1): 8-17, 2015 Feb.
Article de Anglais | MEDLINE | ID: mdl-25420125

RÉSUMÉ

Psychometric studies suggest that observed self-concept deficits in addicted massively multiplayer online role-playing game (MMORPG) are compensated through the replacement of their ideal (i.e., how an individual would like to be) by their own avatar (i.e., graphical agent in the virtual world). Neurobiological studies indicate that increased identification with their own avatar in regular MMORPG gamers is possibly reflected by enhanced avatar-referential brain activation in the left angular gyrus (AG). However, the neurobiological correlates reflecting the relations of the avatar to addicted gamers' self and ideal are still unexplored. Therefore, we compare these relations between addicted and nonaddicted MMORPG gamers. A sample of n = 15 addicted and n = 17 nonaddicted players underwent functional MRI (fMRI) while completing a Giessen-Test (GT)-derived paradigm assessing self-, ideal-, and avatar-related self-concept domains. Neurobiological analyses included the comparisons avatar versus self, avatar versus ideal, and avatar versus self, ideal. Psychometrically, addicts showed significantly lower scores on the self-concept subscale of 'social resonance,' that is, social popularity. In all avatar-related contrasts, within-group comparisons showed addicted players to exhibit significantly higher brain activations in the left AG. The between-groups comparisons revealed avatar-related left AG hyperactivations in addicts. Our results may suggest that addicted MMORPG players identify significantly more with their avatar than nonaddicted gamers. The concrete avatar might increasingly replace the rather abstract ideal in the transition from normal- controlled to addictive-compulsive MMORPG usage.


Sujet(s)
Comportement toxicomaniaque/physiopathologie , , Lobe pariétal/physiopathologie , Jeu de rôle , Concept du soi , Jeux vidéo/psychologie , Adulte , Comportement toxicomaniaque/psychologie , Cartographie cérébrale , Femelle , Humains , Internet , Imagerie par résonance magnétique , Mâle , Interface utilisateur , Jeune adulte
16.
J Neurosci Methods ; 239: 170-82, 2015 Jan 15.
Article de Anglais | MEDLINE | ID: mdl-25445785

RÉSUMÉ

BACKGROUND: To translate highly accelerated EPI-fMRI protocols as commonly used at ultra-high field strengths to clinical 3T settings. NEW METHOD: EPI protocols with increasing matrix sizes and parallel imaging (PI) factors were tested in two separate fMRI studies, a simple motor-task and a complex motivation-task experiment with focus on the sensorimotor cortex (SMC) and the nucleus accumbens (NAcc), respectively. RESULTS: By increasing the matrix size and the PI-factor simultaneously, BOLD-sensitivity in terms of maximal t-values and numbers of activated clusters was uncompromised in single individuals in both fMRI experiments. In the SMC, the multi-subject analysis revealed an increase of 66% of the maximal t-value whereby the number of activated clusters was increased by a factor of 3.3 when the matrix size (PI-factor) was increased from 96×96 (R=2) to 192×192 (R=4). In the NAcc, the number of activated clusters increased from 5 to 7 whereby the maximal t-value remained unaffected when the matrix size (PI-factor) was increased from 96×96 (R=2) to 160×160 (R=3). COMPARISON WITH EXISTING METHOD: Using the proposed high-resolution EPI protocol, spatial blurring was clearly reduced. Further, BOLD sensitivity was clearly improved in multi-subject analyses and remained unaffected in single individuals compared to using the standard protocols. CONCLUSIONS: Conventionally used matrix sizes (PI-factors) might be non-optimal for some applications sacrificing BOLD spatial specificity. We recommend using the proposed high-resolution protocols applicable in detecting robust BOLD activation in fMRI.


Sujet(s)
Cartographie cérébrale , Encéphale/anatomie et histologie , Encéphale/vascularisation , Imagerie échoplanaire , Imagerie tridimensionnelle , Imagerie par résonance magnétique , Adulte , Encéphale/physiologie , Femelle , Humains , Modèles linéaires , Mâle , Motivation , Performance psychomotrice , Jeune adulte
17.
Int J Psychophysiol ; 94(3): 263-71, 2014 Dec.
Article de Anglais | MEDLINE | ID: mdl-25269022

RÉSUMÉ

Previous research on alcohol dependent patients has shown that variations in eyeblink startle response can be used as an indicator of their emotional responses to alcohol-related stimuli. Postulating that reactions on substance associated stimuli are controlled by either a negative or a positive affective processing system, we expect that abstinent alcoholics react differently (within-group) in the emotional evaluation of alcohol cues. Furthermore, we assumed the startle response to covary with medication response to acamprosate and naltrexone. We measured 74 detoxified inpatients' acoustic startle responses while they were being presented with alcohol-related images as well as affectively negative, neutral, and positive pictures before they were randomized to pharmacotherapy. Group-mean startle peak amplitudes were lowest for alcohol-related cues. The relative startle response (alcohol cues set in relation to the other stimulus categories) did not correlate with craving for alcohol (OCDS) or alcohol cue induced self-ratings of arousal, valence and craving. Patients with a lower percentage of abstinent days in the 90 days prior to the last drinking day showed a lower ("more appetitive") startle response to alcohol cues. A survival analysis using the time to first heavy drinking day as the survival criterion revealed a significant interaction between alcohol-cue startle responses and medication type. The results indicate that the psycho-physiological measure of emotional evaluation of alcohol cues includes unconscious processing not reflected by conscious self-ratings. Furthermore, our result of a differential medication effect may encourage further studies to use biological characteristics to stratify patients as a step towards individualized treatment for alcohol dependence.


Sujet(s)
Consommation d'alcool/psychologie , Alcoolisme/psychologie , Clignement , Signaux , Stimulation lumineuse/méthodes , Réflexe de sursaut , Adulte , Consommation d'alcool/épidémiologie , Alcoolisme/diagnostic , Alcoolisme/épidémiologie , Clignement/physiologie , Femelle , Humains , Mâle , Adulte d'âge moyen , Réflexe de sursaut/physiologie
18.
Conscious Cogn ; 29: 199-211, 2014 Oct.
Article de Anglais | MEDLINE | ID: mdl-25286129

RÉSUMÉ

Performance on tasks requiring discrimination of at least two stimuli can be viewed either from an objective perspective (referring to actual stimulus differences), or from a subjective perspective (corresponding to participant's responses). Using event-related potentials recorded during an old/new recognition memory test involving emotionally laden and neutral words studied either blockwise or randomly intermixed, we show here how the objective perspective (old versus new items) yields late effects of blockwise emotional item presentation at parietal sites that the subjective perspective fails to find, whereas the subjective perspective ("old" versus "new" responses) is more sensitive to early effects of emotion at anterior sites than the objective perspective. Our results demonstrate the potential advantage of dissociating the subjective and the objective perspective onto task performance (in addition to analyzing trials with correct responses), especially for investigations of illusions and information processing biases, in behavioral and cognitive neuroscience studies.


Sujet(s)
Émotions/physiologie , Potentiels évoqués/physiologie , Mémoire épisodique , Rappel mnésique/physiologie , Performance psychomotrice/physiologie , /physiologie , Adulte , Femelle , Humains , Mâle , Jeune adulte
19.
PLoS One ; 9(9): e106411, 2014.
Article de Anglais | MEDLINE | ID: mdl-25264982

RÉSUMÉ

Memory judgments can be based on accurate memory information or on decision bias (the tendency to report that an event is part of episodic memory when one is in fact unsure). Event related potentials (ERP) correlates are important research tools for elucidating the dynamics underlying memory judgments but so far have been established only for investigations of accurate old/new discrimination. To identify the ERP correlates of bias, and observe how these interact with ERP correlates of memory, we conducted three experiments that manipulated decision bias within participants via instructions during recognition memory tests while their ERPs were recorded. In Experiment 1, the bias manipulation was performed between blocks of trials (automatized bias) and compared to trial-by-trial shifts of bias in accord with an external cue (flexibly controlled bias). In Experiment 2, the bias manipulation was performed at two different levels of accurate old/new discrimination as the memory strength of old (studied) items was varied. In Experiment 3, the bias manipulation was added to another, bottom-up driven manipulation of bias induced via familiarity. In the first two Experiments, and in the low familiarity condition of Experiment 3, we found evidence of an early frontocentral ERP component at 320 ms poststimulus (the FN320) that was sensitive to the manipulation of bias via instruction, with more negative amplitudes indexing more liberal bias. By contrast, later during the trial (500-700 ms poststimulus), bias effects interacted with old/new effects across all three experiments. Results suggest that the decision criterion is typically activated early during recognition memory trials, and is integrated with retrieved memory signals and task-specific processing demands later during the trial. More generally, the findings demonstrate how ERPs can help to specify the dynamics of recognition memory processes under top-down and bottom-up controlled retrieval conditions.


Sujet(s)
Prise de décision , Potentiels évoqués , Mémoire , Adulte , Femelle , Humains , Mâle , Modèles théoriques , Jeune adulte
20.
Addict Behav ; 39(12): 1789-97, 2014 Dec.
Article de Anglais | MEDLINE | ID: mdl-25123348

RÉSUMÉ

AIMS: MMORPG addiction has been associated with self-concept impairments and increased identification with the own avatar. Yet, the underlying neurobiological mechanisms of self-identification with avatars, especially reflected in the left angular gyrus (AG), have only been assessed in regular gamers. Therefore, the study aims to examine neurobiological processes in addicted MMORPG players while evaluating their own and their personal avatar's body image (physical self-concept). METHODS: Sixteen addicted and seventeen non-addicted gamers underwent functional Magnetic Resonance Imaging (fMRI) while viewing images of themselves, their own avatar and unfamiliar persons. The Body Image Questionnaire (FKB-20) and Visual Analog Scales (VAS) assessing the degree of attractiveness, sympathy and gender identity of the self, of the avatar as well as of the unfamiliar persons were applied. RESULTS: Addicts showed a significantly extended negative body image and lower gender identity levels as well as decreased bilateral brain activations in the AG and the middle occipital gyrus during self-perception. They further exhibited higher activations in the left AG during avatar-perception. Regression analyses in the overall group and in addicted gamers indicated a significant positive correlation between gender identity and brain activation in the left AG during self-perception. CONCLUSIONS: Our results confirm addicted MMORPG players to have physical self-concept deficits which may be related to hypoactivations in the AG. The findings further indicate addicted gamers to have a tendency to identify themselves easier with their own avatar than with their real self. Lower gender identity levels might be associated with physical self-concept deficits in MMORPG addiction.


Sujet(s)
Comportement toxicomaniaque/psychologie , Encéphale/physiopathologie , , Jeu de rôle , Concept du soi , Jeux vidéo/psychologie , Adulte , Image du corps/psychologie , Cartographie cérébrale/méthodes , Femelle , Humains , Internet , Imagerie par résonance magnétique/méthodes , Mâle , Psychométrie , Enquêtes et questionnaires , Jeux vidéo/statistiques et données numériques , Jeune adulte
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