Intentional Switching Between Bimanual Coordination Patterns in Older Adults: Is It Mediated by Inhibition Processes?

Background: Cognitive control of brain regions can be determined by the tasks involving the cognitive control such as the color word Stroop task. Stroop task define the reduction in function in incongruent condition, which requires more attention and control of competitive responses.Objective: The purpose of this study was to evaluate the activity of brain using the Modified Conflict Stroop Task in Military Personnel.Material and Methods: In this applied experimental study, to specify the activity of different regions of brain in response to conflict Persian color-word Stroop task, 20 healthy persons participated in this study. To evaluate selective attention, the traditional color-word Stroop Task Model was modified, and the Stroop test was designed in high- and low-threat zones. We used functional magnetic resonance imaging (fMRI) to evaluate the brain activation during the Stroop task performance. The color-word Stroop task consists of incongruent, congruent, and neutral conditions, and the subjects were requested to carefully choose the correct answer.Results: The mean response time was longer in incongruent condition (867.6±193.5ms) compared to congruent and neutral conditions. Analysis of neuroimaging data revealed that the brain conflict-related regions are activated by the Stroop interference. In incongruent trial, the superior frontal gyrus (SFG) and inferior frontal gyrus (IFG) showed the most active and stronger BOLD responses. In congruent trials, the activation in the brain was less and had difference compared with incongruent trials. Conclusion: Our result offers that the frontal cortex and the anterior cingulate cortex are sensitive to different trials of Persian Stroop task. Using modified Stroop task, we determined the brain responses to the selective attention test.

Objective To discuss the neuropsychological mechanism of executive control for methadone maintenance patients( MMP). Methods Using the event-related potentials (ERPs) technique to reveal the time course of information processes with high temporal resolution, and exam the function of attention monitoring and response inhibition in heroin-dependent MMP. Results (1)The behavioral results: there were significant within-subjects Stroop interference effects for the MMP and control groups(reaction time: control group’s congruent condition(766.57±75.64)ms, incongruent condition(879.52±62.31)ms, MMP group’s congruent condition (821.89± 64.44)ms, incongruent condition(906.29±69.46)ms, P<0.001; error rate: control group’s congruent condition (4.15±2.92)%, incongruent condition(8.70±6.12)%, P<0.001, MMP group’s congruent condition(12.07±10.80)%, incongruent condition (16.60±12.43)%, P<0.01). (2)ERPs data showed that MMP demonstrated significantly smaller incongruent-N2/N450/SP amplitudes than controls, and all disappearing incongruent effects in N2, N450 and SP, comparing statistically significant incongruent effects for controls in N2, N450 and SP. In MMP group, the amplitudes of N2 and N450 incongruent condition(N2(1.40±2.91)μV、N450(1.29±0.55)μV) were bigger than congruent condition amplitudes(N2(0.77±3.61)μV、N450(0.83±1.07)μV, P<0.05), but the amplitude of SP (0.37±3.58)μV was smaller than congruent condition(1.53±3.05)μV, P<0.001; in control group, the amplitudes of N2 and N450 incongruent condition((-0.30±3.45)μV, N450(1.77±1.55)μV) were smaller than congruent condition (N2(1.10±3.64)μV, P<0.001; N450(2.37±2.12)μV, P<0.05), the amplitude of SP ((1.93±1.65)μV) was bigger than congruent condition((0.98±2.02)μV, P<0.01). Conclusion There are impaired executive control functions during the conflict monitoring process and the conflict resolution process for MMP. These results provide the neural electrophysiological evidence to explain relapse behaviors in methadone maintenance patients. Key words: Methadone maintenance patients; Stroop effect; Executive control; Event-related potentials

Introduction: The purpose of present research was the study of the effect of sensory feedback on speed of the relative phase transition in anti-phase bimanual coordination pattern across old adults. Materials and Methods: Therefore 15 intact male old adults selected in available with age range 60-70 years that were all of them hand-right. Participants started their movement on bimanual coordination device with anti-phase at frequency 0.75 Hz and was increased to it 0.25 Hz by step 5 seconds and final frequency was 5 Hz. Present task performed under 8 sensory conditions. For investigating data used repeated measures analysis of variance 2 × 2 × 2 and paired-samples t-test with Bonferroni correction for pair comparisons of the interaction effects. Results: The findings revealed that main effects of proprioception (P = 0.001), audition (P = 0.001) and two-way interaction (P = 0.022) were significant. These results implied to positive effects of audition and proprioception feedback and also more effect of exist of audition information along with lack of vision on the speed of relative phase transition. Conclusion: The findings reflected that the performance of present bimanual coordination task was under close-loop control system. Also the results reflect the role of control parameter in performing coordinated movement and relative phase transition from one inconsistence pattern to another more consistence pattern as movement speed increased. With regard to older adults revealed more impairments in audition and proprioception than vision condition and also more variability and the speed of the phase transition, we could conclude that these population relied on audition and proprioception to perform bimanual coordination patterns.

Effects of attention on phase transitions between bimanual coordination patterns: a behavioral and cost analysis in humans.

Hippocampal and Orbitofrontal Theta Band Coherence Diminishes During Conflict Resolution

Objective:Neuronal dysfunction of the locus coeruleus (LC), the primary producer of norepinephrine, has been identified as a biomarker of early Alzheimer's disease (AD) pathophysiology. Norepinephrine has been implicated in attentional control, and its reduced cortical circulation in AD may be associated with selective attentional difficulties. Additionally, greater pupil dilation indicates greater effort needed to perform a cognitive task, and greater compensatory effort to perform the digit span task has been found in individuals at risk for AD. In this study, we examined associations between a neuroimaging biomarker of the LC and pupil dilation during the Stroop task as a sensitive measure of attentional control.Participants and Methods:64 older adults without dementia were recruited from the San Diego community (mean [SD] age = 74.3 [6.3]; 39 cognitively unimpaired and 25 with mild cognitive impairment). All participants underwent magnetic resonance imaging of the LC and generated behavioral data from a computerized Stroop task that included 36 incongruent trials (e.g., GREEN presented in red ink), 36 congruent trials (e.g., GREEN presented in green ink), and 32 neutral trials (e.g., LEGAL presented in green ink) in a randomized presentation. Mean pupil dilation for each trial (change relative to baseline at the start of each trial) was measured at 30 Hz using the Tobii X2-30 system (Tobii, Stockholm, Sweden) and averaged within each Stroop condition. Paired t-tests assessed for differences in mean pupil dilation across incongruent and congruent Stroop conditions. Iterative re-weighted least squares regression was used to assess the association between a rostral LC contrast ratio measure derived from manually marked ROIs and mean pupil dilation during incongruent trials divided by congruent trials, adjusting for age, sex, and education. Follow-up analyses also assessed the association of these variables with mean reaction time (RT) for incongruent trials divided by congruent trials.Results:Mean pupil dilation significantly differed across conditions (t = 3.74, mean difference = .13, 95% CI [.06, .20]) such that dilation was higher during the incongruent condition (mean [SD] dilation = .18 [.38] mm) relative to the congruent condition (mean [SD] dilation = .05 [.35] mm). A significant association was observed between pupil dilation and LC contrast ratio, such that increased levels of mean dilation during incongruent trials relative to congruent trials were observed at lower levels of LC contrast ratio (i.e., lower LC integrity; r = -.37, 95% CI [-.55, -.13]). This association was not observed for mean dilation during only congruent trials (r = -.08, 95% CI [-.31, .18]). Additionally, neither LC contrast ratio [r = .24, 95% CI [-.02, .46]) nor mean incongruent/congruent pupil dilation (r = .14, 95% CI [-.13, .37]) were associated with incongruent/congruent RT.Conclusions:Findings suggest that increased pupil dilation during a demanding attentional task is indicative of increased compensatory effort needed to achieve the same level of performance for individuals with reduced LC biomarker integrity. Pupillometry assessment offers a low-cost, non-invasive, and scalable biomarker of LC dysfunction that may be indicative of preclinical AD.

In a Stroop task, participants can be presented with a color name printed in color and need to classify the print color while ignoring the word. The Stroop effect is typically calculated as the difference in mean response time (RT) between congruent (e.g., the word RED printed in red) and incongruent (GREEN in red) trials. Delta plots compare not just mean performance, but the entire RT distributions of congruent and incongruent conditions. However, both mean RT and delta plots have some limitations. Arm-reaching trajectories allow a more continuous measure for assessing the time course of the Stroop effect. We compared arm movements to congruent and incongruent stimuli in a standard Stroop task and a control task that encourages processing of each and every word. The Stroop effect emerged over time in the control task, but not in the standard Stroop, suggesting words may be processed differently in the two tasks.

Contents: Preface. Section I: Action. Part 1: Posture and Locomotion. V. Dechelette, Y. Guiard, Dynamic and Postural Preparation for Tennis Strokes: An Analysis of Stance in Professional Players. A. Delorme, J-Y. Frigon, M-C. Grothe, Postural Reactions to a Moving Environment: Influence of Ageing in Adults. L. Mouchnino, M-L. Mille, M. Cincera, A. Bardot, A. Delarque, Weight-Shifting Strategy in Below-Knee Amputees During Lateral Raising of the Leg. K. Gorday, M. Stroop, K. Adolph, E. Thelen, Toddlers' Postural Control on Different Surfaces. F. Eves, Contributions of Peripheral and Central Vision to Long Jumping. F. Danion, M. Bonnard, J. Pailhous,How Can Human Gait Be Adapted to an Imbalance Between Flexion and Extension Forces? Part 2: Interlimb Coordination. P. Amazeen, The Effect of Frequency Detuning on Learning to Stabilize a Dynamically Unstable Phase Relation. E. Amazeen, Experimental Control of the Nonlinear Drift of Coordination Equilibria. W. Byblow, Phase Attractive Dynamics and Performance Asymmetries in Bimanual Coordination. R. Carson, W. Byblow, B. Abernethy, J. Summers, Inherent and Incidental Constraints Upon Intentional Switching Between Patterns of Bimanual Coordination. D. Collins, The Detuning Factor in Elementary Coordination Dynamics. S. Mitra, P. Amazeen, Breaking the Symmetry Between Spatial and Joint Phase Space in Interlimb Coordination. B. Steenbergen, W. Hulstijn, A. de Vries, M. Berger, One- and Two-Handed Reaching and Grasping in Subjects With Spastic Hemiparesis: Asymmetry Effects. D. Sternad, E. Saltzman, Dynamics of 1:2 Interlimb Coordination in Rhythmic Movement. R. van Emmerik, R. Wagenaar, Tremor and Symmetry Properties in Bimanual Coordination in Parkinson's Disease. T. Ferrand, Y. Guiard, Fitts' Law in Cooperative Two-Person Aiming. B. O'Brien, R. Schmidt, The Dynamics of Unintentional Interpersonal Entrainment. Part 3: Control of Arm Movement. P. Beek, L. Peper, A. Post, J. Reijnen,Orbital Stability of Rhythmic Forearm Movements. D. Mottet, M-A. Dupuy, M-M. Ramanantsoa, B. Pavis, D. Artus, H. Ripoll, A Task-Dynamic Approach to Throwing Skills. P. Treffner, S. Kelso, Functional Stabilization of Unstable Fixed-Points. C. Volman, R. Geuze, Development of Temporal Stability in Unimanual Perception-Action Coupling. D. Mottet, R. Bootsma, A Dynamical Model for Fitts' Task. R. Schmidt, D. Corey, P. Fitzpatrick, M. Riley, The Oscillatory Basis of Fitts' Law. M. Sasaki, H. Mishima, K. Suzuki, M. Ohkura, Observations on Micro-Exploration in Everyday Activities. S. Spellerberg, W. Spijkers, Visual Guidance of Discrete Aiming Movements. R. Wimmers, G. Savelsbergh, P. Beek, B. Hopkins, Preliminary Evidence for a Developmental Transition from Reaching to Grasping Proper. F. Zaal, P. van Wieringen, Predetermined or Emergent Timing in Reaching to Pick Up a Moving Object. A. Bateman, J. Riddoch, G. Humphreys, S. Townsend, D. Francis, Hemisphere Specialization for Action Systems? D. Sternad, S. Schaal, C. Atkeson, Batting of a Ball: Dynamics of a Rhythmic Skill. F. Melo, Emotional State Effects on the Control of Precision Movement. Section II: Action - Perception Coupling. Part 1: Affordances. L. Mark,Perceiving the Preferred Critical Boundary for an Affordance. O. Flascher, R. Shaw, E. Kadar, T. Aromin, Intentional Perceptual Scaling Means pi(symbol) = 1. R. Pijpers, F. Bakker, Perceiving Conflicting Affordances. J. Barreiros, P. Silva, Hand Size and Grasping in Infants. C. Palmer, A. Chinitz, M. Haven, E. Greines, J. Chandler, Preschoolers' Accuracy Judging and Jumping Distances. S. Flynn, C. Henderson, The Role of Object-Actor Relative Motion in the Perception of Caught Weight. T. Stoffregen, S. Yang-Yi, K. Gorday, Perceiving Affordances for Another Person's Actions. Part 2: Laws of Control. B. Bardy, W. Warren, B. Kay, Motion Parallax Is Used to Control Posture During Walking. B. Frey, An Active Control Paradigm for the Study of Heading Perception. L. Marin, Supra-Postural Control in a Rotary Optical Flow. J. Wann, S. Rushton, D. Lee, Can You Control Where You Are Heading When You Are Looking at Where You Want to Go? A. Boyadjian, Timing in Relay Running. A. Durey, M-M. Ramanantsoa, A Quantitative Study of Parameters of Control in Approaching the Water Ski Ramp. V. Fayt, Visual Timing of a Striking Action Under Varying Approach Conditions. N-G. Kim, J. Effken, How the Future Is Specified: A Hypothesis. F-X. Li, M. Laurent, Intensity Coupling in Interceptive Tasks. F-X. Li, Intensity Coupling in Peripheral Vision. T. Stoffregen, C. Henderson, M. Sasaki, Varying the t(symbol)-Margin. M. Mulder, E. Theunissen, H. van der Vaart, Perspective Flight-Path Displays and Time-to-Wall-Crossing. J. Wann, S. Rushton, Grasping the Impossible: Stereoscopic Virtual Balls. R. van der Weel, A. van der Meer, J. Hoff, R. Ingvaldsen, Perceptual Control of Force in Slalom Skiing. Part 3: Representation. M-A. Amorim, J. Loomis, S. Fukusima, Spatial Updating of Object Shape During Real and Imagined Viewpoint Change Following Visual Preview. S. Chow, Speech Acts and Their Emplotment. F. Gaunet, C. Thinus-Blanc, Exploratory Patterns and Reactions to Spatial Change: The Role of Early Visual Experience. J. Glicksohn, I. Balmor-Braun, J. Bar-Ziv, M. Myslobodsky, Spatial Orientation and Pineal Calcification. Y. Rossetti, C. Regnier, Representations in Action: Pointing to a Target with Various Representations. M. Gonzales, E. Alves, A. Sette, Self-Organization in the Development of Representation-Action Couplings. Part 4: Development. R. Morgan, P. Rochat, The Perception of Self-Produced Leg Movement in Self- Versus Object-Oriented Contexts by 3-5-Month-Old Infants. A. Ledebt, Head Movement Organization During the First Year of Independent Walking. J. Rose, B. Bertenthal, A Longitudinal Study of the Visual Control of Posture in Infancy. B. Vereijken, K. Adolph, M. Denny, Y. Fadl, S. Gill, A. Lucero, Development of Infant Crawling: Balance Constraints on Interlimb Coordination. A. Davis, G. Bremner, Ecological Theory and Experimental Studies of Children's Drawings. G. Bremner, Perception, Action, and the Development of Knowledge in Infancy. Part 5: Learning. A. van der Meer, R. van der Weel, Keeping the Arm in the Limelight: The Functional Significance of Neonatal Arm Movements. S. Verschueren, S. Swinnen, R. Dom, Interlimb Coordination in Patients with Parkinson's Disease: Learning Capabilities and the Importance of Augmented Visual Information. G. Redding, B. Wallace, Contributions of Motor Control and Spatial Alignment to Prism Adaptation. D. Dinnel, L. Lippman, Familiarization and Rule Generation in a Transformed Perceptual-Motor Task. C. Dominguez, R. Hutton, J. Flach, D. McKellar, Perception-Action Coupling in Endoscopic Surgery: A Cognitive-Task Analysis Approach. J. Romack, Information in Visual Event Perception and Its Use in Observational Learning. Section III: Perception. Part 1: Mechanical Patterns. G. Burton, M-V. Santana, C. Carello, Haptic Decomposition Is Anchored in the Inertia Tensor. T-C. Chan,Haptic Perception of Rod Length: A Case for Relative Realism. A. Peck, Perceiving the Length of One Rod by Means of Another. S. Pont, A. Kappers, J. Koenderink, Haptic Discrimination of Curved Strips. R. Schellingerhout, W. Beyers, A. Smitsman, G. van Gal

Functional near-infrared spectroscopy (fNIRS) is a low-cost, portable and noninvasive functional neuroimaging technique by measuring the change in the concentrations of oxyhemoglobin (HbO) and deoxyhemoglobin (HbR). The aim of present study is to reveal the different brain activity pattern of adult subjects during the completion of flanker and Simon tasks underlying the congruent and incongruent test conditions so as to identify the basic neural mechanism of inhibitory control in executive function. In the study, we utilized fNIRS to explore the hemodynamic changes in the prefrontal cortex and our imaging results suggested that there were notable differences for the hemodynamic responses between the flank and Simon task. A striking difference is that for the flank task, the increase in the HbO concentration during incongruent trials was larger than that during congruent trials for the channels across middle frontal cortex while for the Simon task, the hemodynamic response was stronger for the congruent condition compared to that from the incongruent one. Interestingly, the hemodynamic response exhibited similar task-related activation in the superior frontal cortex for both the congruent and incongruent conditions. Further, independent component analysis showed that different brain activation patterns were identified to accomplish different inhibitory control tasks underlying the congruent and incongruent conditions.

BackgroundA greater congruency of audio and video expands the temporal binding window (TBW). A similar phenomenon may occur with a combination of odor and taste, which are the main components of flavor.ObjectiveTBW is defined as the temporal resolution of synchrony perception. The larger the TBW, the lower the resolution. We hypothesized that the more congruent the odor and taste, the lower the temporal resolution of synchrony perception.MethodsTo examine this hypothesis, 10 female participants performed simultaneity judgment (SJ) tasks under congruent (soy sauce odor with saline) and incongruent (cherry tree leaf odor with saline) conditions and evaluated the congruency with saltiness for the two odors. In the SJ tasks, participants reported whether odor and taste were presented simultaneously or successively. We assumed a Gaussian distribution for the temporal distributions of the simultaneous response rates and calculated the approximations. In addition, we computed the half width at half height (HWHH) as an index of TBW based on the coefficient of approximation for the temporal distribution of the simultaneous response rates.ResultsHWHH was significantly larger under congruent condition than under incongruent condition. In addition, congruency with saltiness had a significant moderate positive correlation with HWHH.ConclusionThe larger the HWHH, the lower the temporal resolution of synchrony perception, supporting the hypothesis. This study suggests that the width of TBW depends on the cross‐modal congruency similar to the case for audio–visual SJs. However, methodological improvements, including a larger sample size and gender‐independent recruitment of participants, are essential to enhance the reliability of the findings because some of the results did not provide sufficient ESs or power.

Background: Very less work has been done in the past to assess cognition in hypothyroid patients using classical color-word Stroop task. The Stroop color-word task is a well-recognized tool which estimates cognitive inhibition. Stroop task is based on the fact that reading words and identifying color of written words are two different information and they process with a common response channel but with different speeds. The aim of this study was to assess the cognitive inhibition process in drug-naive hypothyroid patients and their comparison with the same patients after the attainment of euthyroid status and also with euthyroid controls using classical color-word Stroop task. Materials and Methods: Thirty drug-naive newly diagnosed hypothyroid patients were study cases who underwent Stroop task once before initiating treatment and then after the attainment of euthyroid state. We performed the same test in euthyroid controls twice at an interval of 3 months for comparison purpose. Correlation analysis was also done for hypothyroidism and cognition. Results: The reaction time of Stroop task was decreased in all the three conditions of each block, i.e., neutral, incongruent, and congruent conditions after the attainment of euthyroid state, and the finding confirms posttreatment modulation of the attention processes in hypothyroid patients. Reaction time of Stroop task in hypothyroid patients was positively correlated with the serum thyroid-stimulating hormone levels. Processing of color identification was suppressed than reading words in hypothyroid patients as evidenced by increased reaction time of Stroop task. This increase in reaction time can be reversed by earlier identification of drug-naive hypothyroid cases so that they can get timely treatment to restore their cognitive status. Conclusions: Stroop task scores are reduced in overt hypothyroid patients, but improve after thyroid replacement therapy.

Accurate measurement of small heteronuclear coupling constants from pure-phase α/ β HSQMBC cross-peaks

Shared dynamics of attentional cost and pattern stability

Purpose : An understanding of the relationship between attentional deficits and language processing can provide insight into the language disorders in persons with aphasia (PWA). Especially, executive attention is a critical component of the attentional system. However, the relationships among executive attention, language processing and aphasia have not been studied extensively. The purpose of this study was to investigate the role of goal maintenance and conflict resolution in word-level processing in persons with aphasia (PWA).<BR>Methods : Picture-Word Interference (PWI) tasks were used whereby written words were superimposed on pictures in congruent, neutral or incongruent conditions. Ten PWA and 20 normal individuals (NI) categorized words into animal or non-animal. Button press response times (RT) and error rates were measured.<BR>Results : The results revealed that PWA took significantly (p<.05) longer RTs than NI for the incongruent and neutral conditions, but there was no significant group difference for the congruent conditions. The NI committed significantly more errors on the lower proportion of the incongruent trial, however, the PWA showed no significant difference between two proportions of the PWI tasks.<BR>Conclusions : The PWA group evidenced impaired conflict resolution and goal maintenance under the PWI tasks. The fact that the PWA group was vulnerable to both demands of conflict resolution and goal maintenance suggests that the PWA group demonstrated impaired executive attention compared to the NI.

The role of the pain-evoked negative difference potential in dual-task response conflict