Displaying publications 1 - 20 of 31 in total

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  1. Lee LK, Shahar S, Chin AV, Yusoff NA
    Psychopharmacology (Berl), 2013 Feb;225(3):605-12.
    PMID: 22932777 DOI: 10.1007/s00213-012-2848-0
    RATIONALE: Epidemiological studies have suggested a beneficial effect of fish oil supplementation in halting the initial progression of Alzheimer's disease. However, it remains unclear whether fish oil affects cognitive function in older people with mild cognitive impairment (MCI).

    OBJECTIVES: This study investigated the effects of fish oil supplementation on cognitive function in elderly person with MCI.

    METHODS: This was a 12-month, randomised, double-blind, placebo-controlled study using fish oil supplementation with concentrated docosahexaenoic acid (DHA). Thirty six low-socioeconomic-status elderly subjects with MCI were randomly assigned to receive either concentrated DHA fish oil (n = 18) or placebo (n = 18) capsules. The changes of memory, psychomotor speed, executive function and attention, and visual-constructive skills were assessed using cognitive tests. Secondary outcomes were safety and tolerability of the DHA concentrate.

    RESULTS: The fish oil group showed significant improvement in short-term and working memory (F = 9.890; ηp (2) = 0.254; p 

    Matched MeSH terms: Psychomotor Performance/drug effects*
  2. Ding Y, He T, Satel J, Wang Z
    Atten Percept Psychophys, 2016 05;78(4):1020-9.
    PMID: 26956560 DOI: 10.3758/s13414-016-1079-6
    With two cueing tasks, in the present study we examined output-based inhibitory cueing effects (ICEs) with manual responses to arrow targets following manual or saccadic responses to arrow cues. In all experiments, ICEs were observed when manual localization responses were required to both the cues and targets, but only when the cue-target onset asynchrony (CTOA) was 2,000 ms or longer. In contrast, when saccadic responses were made in response to the cues, ICEs were only observed with CTOAs of 2,000 ms or less-and only when an auditory cue-back signal was used. The present study also showed that the magnitude of ICEs following saccadic responses to arrow cues decreased with time, much like traditional inhibition-of-return effects. The magnitude of ICEs following manual responses to arrow cues, however, appeared later in time and had no sign of decreasing even 3 s after cue onset. These findings suggest that ICEs linked to skeletomotor activation do exist and that the ICEs evoked by oculomotor activation can carry over to the skeletomotor system.
    Matched MeSH terms: Psychomotor Performance/physiology*
  3. Zadry HR, Dawal SZ, Taha Z
    Int J Occup Saf Ergon, 2011;17(4):373-84.
    PMID: 22152503
    A study was conducted to investigate the effects of repetitive light tasks of low and high precision on upper limb muscles and brain activities. Surface electromyography (EMG) and electroencephalography (EEG) were used to measure the muscle and brain activity of 10 subjects. The results show that the root-mean-square (RMS) and mean power frquency (MPF) of the muscle activity and the mean power of the EEG alpha bands were higher on the high-precision task than on the low-precision one. There was also a high and significant correlation between upper limb muscle and brain activity during the tasks. The longer the time and the more precise the task, the more the subjects become fatigued both physically and mentally. Thus, these results could be potentially useful in managing fatigue, especially fatique related to muscle and mental workload.
    Matched MeSH terms: Psychomotor Performance/physiology*
  4. Yap KH, Abdul Manan H, Sharip S
    Behav Brain Res, 2021 01 15;397:112888.
    PMID: 32882284 DOI: 10.1016/j.bbr.2020.112888
    This review aims to establish the cognitive processing of patients with attention-deficit hyperactive disorder (ADHD) across age. Functional magnetic resonance imaging (fMRI) studies on children and adult populations were conducted, thus delineating deficits that could have been maintained and ameliorated across age. This allowed for the examination of the correlation between patterns of brain activation and the corresponding development of functional heterogeneity in ADHD. A systematic literature search of fMRI studies on ADHD was conducted using the PubMed and Scopus electronic databases based on PRISMA guidelines. References and citations were verified in Scopus database. The present study has identified 14 studies on children, 16 studies on adults, and one study on both populations of ADHD consisting of 1371 participants. Functional heterogeneity is present in ADHD across age, which can manifest either as different brain activation patterns, intra-subject variability, or both. This is shown in the increased role of the frontal regions and the specialized network in adults with ADHD from inefficient non-specific activation in childhood. Functional heterogeneity may manifest when delayed maturation is insufficient to normalize frontal lobe functions.
    Matched MeSH terms: Psychomotor Performance/physiology*
  5. Hilchey MD, Klein RM, Satel J
    J Exp Psychol Hum Percept Perform, 2014 Aug;40(4):1603-16.
    PMID: 24820438 DOI: 10.1037/a0036859
    We explored the nature and time course of effects generated by spatially uninformative peripheral cues by measuring these effects with localization responses to peripheral onsets or central arrow targets. In Experiment 1, participants made saccadic eye movements to equiprobable peripheral and central targets. At short cue-target onset asynchronies (CTOAs), responses to cued peripheral stimuli suffered from slowed responding attributable to sensory adaptation while responses to central targets were transiently facilitated, presumably due to cue-elicited oculomotor activation. At the longest CTOA, saccadic responses to central and peripheral targets were indistinguishably delayed, suggesting a common, output/decision effect (inhibition of return; IOR). In Experiment 2, we tested the hypothesis that the generation of this output effect is dependent on the activation state of the oculomotor system by forbidding eye movements and requiring keypress responses to frequent peripheral targets, while probing oculomotor behavior with saccades to infrequent central arrow targets. As predicted, saccades to central arrow targets showed neither the early facilitation nor later inhibitory effects that were robust in Experiment 1. At the long CTOA, manual responses to cued peripheral targets showed the typical delayed responses usually attributed to IOR. We recommend that this late "inhibitory" cueing effect (ICE) be distinguished from IOR because it lacks the cause (oculomotor activation) and effect (response bias) attributed to IOR when it was named by Posner, Rafal, Choate, and Vaughan (1985).
    Matched MeSH terms: Psychomotor Performance/physiology*
  6. Eng V, Lim A, Kwon S, Gan SR, Jamaluddin SA, Janssen SMJ, et al.
    Atten Percept Psychophys, 2017 May;79(4):1097-1106.
    PMID: 28229429 DOI: 10.3758/s13414-017-1295-8
    There are thought to be two forms of inhibition of return (IOR) depending on whether the oculomotor system is activated or suppressed. When saccades are allowed, output-based IOR is generated, whereas input-based IOR arises when saccades are prohibited. In a series of 4 experiments, we mixed or blocked compatible and incompatible trials with saccadic or manual responses to investigate whether cueing effects would follow the same pattern as those observed with more traditional peripheral onsets and central arrows. In all experiments, an uninformative cue was displayed, followed by a cue-back stimulus that was either red or green, indicating whether a compatible or incompatible response was required. The results showed that IOR was indeed observed for compatible responses in all tasks, whereas IOR was eliminated for incompatible trials-but only with saccadic responses. These findings indicate that the dissociation between input- and output-based forms of IOR depends on more than just oculomotor activation, providing further support for the existence of an inhibitory cueing effect that is distinct to the manual response modality.
    Matched MeSH terms: Psychomotor Performance/physiology
  7. Ting CM, Seghouane AK, Khalid MU, Salleh ShH
    Neural Comput, 2015 Sep;27(9):1857-71.
    PMID: 26161816 DOI: 10.1162/NECO_a_00765
    We consider the problem of selecting the optimal orders of vector autoregressive (VAR) models for fMRI data. Many previous studies used model order of one and ignored that it may vary considerably across data sets depending on different data dimensions, subjects, tasks, and experimental designs. In addition, the classical information criteria (IC) used (e.g., the Akaike IC (AIC)) are biased and inappropriate for the high-dimensional fMRI data typically with a small sample size. We examine the mixed results on the optimal VAR orders for fMRI, especially the validity of the order-one hypothesis, by a comprehensive evaluation using different model selection criteria over three typical data types--a resting state, an event-related design, and a block design data set--with varying time series dimensions obtained from distinct functional brain networks. We use a more balanced criterion, Kullback's IC (KIC) based on Kullback's symmetric divergence combining two directed divergences. We also consider the bias-corrected versions (AICc and KICc) to improve VAR model selection in small samples. Simulation results show better small-sample selection performance of the proposed criteria over the classical ones. Both bias-corrected ICs provide more accurate and consistent model order choices than their biased counterparts, which suffer from overfitting, with KICc performing the best. Results on real data show that orders greater than one were selected by all criteria across all data sets for the small to moderate dimensions, particularly from small, specific networks such as the resting-state default mode network and the task-related motor networks, whereas low orders close to one but not necessarily one were chosen for the large dimensions of full-brain networks.
    Matched MeSH terms: Psychomotor Performance
  8. García-Orza J, Estudillo AJ, Calleja M, Rodríguez JM
    Psychon Bull Rev, 2017 Dec;24(6):1906-1914.
    PMID: 28138835 DOI: 10.3758/s13423-017-1231-x
    Knowing the place-value of digits in multi-digit numbers allows us to identify, understand and distinguish between numbers with the same digits (e.g., 1492 vs. 1942). Research using the size congruency task has shown that the place-value in a string of three zeros and a non-zero digit (e.g., 0090) is processed automatically. In the present study, we explored whether place-value is also automatically activated when more complex numbers (e.g., 2795) are presented. Twenty-five participants were exposed to pairs of four-digit numbers that differed regarding the position of some digits and their physical size. Participants had to decide which of the two numbers was presented in a larger font size. In the congruent condition, the number shown in a bigger font size was numerically larger. In the incongruent condition, the number shown in a smaller font size was numerically larger. Two types of numbers were employed: numbers composed of three zeros and one non-zero digit (e.g., 0040-0400) and numbers composed of four non-zero digits (e.g., 2795-2759). Results showed larger congruency effects in more distant pairs in both type of numbers. Interestingly, this effect was considerably stronger in the strings composed of zeros. These results indicate that place-value coding is partially automatic, as it depends on the perceptual and numerical properties of the numbers to be processed.
    Matched MeSH terms: Psychomotor Performance/physiology*
  9. Wang CY, Chiu CL, Har KO, Chan C, Rahman ZA
    Int J Oral Maxillofac Surg, 2002 Oct;31(5):506-10.
    PMID: 12418566
    This study compares the use of inhalation sedation using sevoflurane (group S) with inhalation sedation using nitrous oxide (group N) in patients undergoing bilateral extraction of third molar teeth under local anaesthesia. The study was designed as a cross-over study. Seventeen ASA I, day surgery patients were studied. Patients were randomly allocated to receive either 8 l/min 50% nitrous oxide in oxygen (group N) or same flow of 1% sevoflurane (group S) for the first procedure. Each patient then had the alternate method of sedation for the second procedure. There were no significant differences between the methods in patient co-operation and surgeon's satisfaction with sedation. Psychomotor tests were comparable in both groups. The patients were significantly more sedated in the group S compared to group N (P=0.004). Significantly more patients complained of an unpleasant odour group S (P<0.01) but none withdrew from the study for this reason. No adverse cardiorespiratory effects resulted from sevoflurane or nitrous oxide sedation. Both methods gave good amnesia during the procedure. There was high acceptance of both methods and the patients rated the technique as equally satisfactory. We conclude that inhalation sedation with sevoflurane is a suitable alternative method to nitrous oxide sedation.
    Matched MeSH terms: Psychomotor Performance/drug effects
  10. Huan NJ, Palaniappan R
    J Neural Eng, 2004 Sep;1(3):142-50.
    PMID: 15876633
    In this paper, we have designed a two-state brain-computer interface (BCI) using neural network (NN) classification of autoregressive (AR) features from electroencephalogram (EEG) signals extracted during mental tasks. The main purpose of the study is to use Keirn and Aunon's data to investigate the performance of different mental task combinations and different AR features for BCI design for individual subjects. In the experimental study, EEG signals from five mental tasks were recorded from four subjects. Different combinations of two mental tasks were studied for each subject. Six different feature extraction methods were used to extract the features from the EEG signals: AR coefficients computed with Burg's algorithm, AR coefficients computed with a least-squares (LS) algorithm and adaptive autoregressive (AAR) coefficients computed with a least-mean-square (LMS) algorithm. All the methods used order six applied to 125 data points and these three methods were repeated with the same data but with segmentation into five segments in increments of 25 data points. The multilayer perceptron NN trained by the back-propagation algorithm (MLP-BP) and linear discriminant analysis (LDA) were used to classify the computed features into different categories that represent the mental tasks. We compared the classification performances among the six different feature extraction methods. The results showed that sixth-order AR coefficients with the LS algorithm without segmentation gave the best performance (93.10%) using MLP-BP and (97.00%) using LDA. The results also showed that the segmentation and AAR methods are not suitable for this set of EEG signals. We conclude that, for different subjects, the best mental task combinations are different and proper selection of mental tasks and feature extraction methods are essential for the BCI design.
    Matched MeSH terms: Psychomotor Performance/physiology
  11. Hamedi M, Salleh ShH, Noor AM
    Neural Comput, 2016 06;28(6):999-1041.
    PMID: 27137671 DOI: 10.1162/NECO_a_00838
    Recent research has reached a consensus on the feasibility of motor imagery brain-computer interface (MI-BCI) for different applications, especially in stroke rehabilitation. Most MI-BCI systems rely on temporal, spectral, and spatial features of single channels to distinguish different MI patterns. However, no successful communication has been established for a completely locked-in subject. To provide more useful and informative features, it has been recommended to take into account the relationships among electroencephalographic (EEG) sensor/source signals in the form of brain connectivity as an efficient tool of neuroscience. In this review, we briefly report the challenges and limitations of conventional MI-BCIs. Brain connectivity analysis, particularly functional and effective, has been described as one of the most promising approaches for improving MI-BCI performance. An extensive literature on EEG-based MI brain connectivity analysis of healthy subjects is reviewed. We subsequently discuss the brain connectomes during left and right hand, feet, and tongue MI movements. Moreover, key components involved in brain connectivity analysis that considerably affect the results are explained. Finally, possible technical shortcomings that may have influenced the results in previous research are addressed and suggestions are provided.
    Matched MeSH terms: Psychomotor Performance/physiology*
  12. Rashid A, Suppiah S, Hoo FK, Masiran R
    BMJ Case Rep, 2018 Jan 04;2018.
    PMID: 29301796 DOI: 10.1136/bcr-2017-221129
    We report a case of a healthy, right-hand dominant young male who was a volunteer for a pilot run of a functional MRI (fMRI) study. The fMRI was performed with a 3.0 Tesla MRI scanner using a finger tapping task-based activity. The subjects were instructed to perform flexion of the right thumb and left thumb consecutively (activation task) and neuronal activation in bilateral primary motor cortex (PMC) were observed during each task. One particular subject demonstrated bilateral PMC activation during the left-thumb movement task, instead of the expected activation of the contralateral PMC alone.
    Matched MeSH terms: Psychomotor Performance/physiology*
  13. Yousefi B, Loo CK
    ScientificWorldJournal, 2014;2014:723213.
    PMID: 25276860 DOI: 10.1155/2014/723213
    Research on psychophysics, neurophysiology, and functional imaging shows particular representation of biological movements which contains two pathways. The visual perception of biological movements formed through the visual system called dorsal and ventral processing streams. Ventral processing stream is associated with the form information extraction; on the other hand, dorsal processing stream provides motion information. Active basic model (ABM) as hierarchical representation of the human object had revealed novelty in form pathway due to applying Gabor based supervised object recognition method. It creates more biological plausibility along with similarity with original model. Fuzzy inference system is used for motion pattern information in motion pathway creating more robustness in recognition process. Besides, interaction of these paths is intriguing and many studies in various fields considered it. Here, the interaction of the pathways to get more appropriated results has been investigated. Extreme learning machine (ELM) has been implied for classification unit of this model, due to having the main properties of artificial neural networks, but crosses from the difficulty of training time substantially diminished in it. Here, there will be a comparison between two different configurations, interactions using synergetic neural network and ELM, in terms of accuracy and compatibility.
    Matched MeSH terms: Psychomotor Performance/physiology
  14. Chen AH, Bleything W, Lim YY
    Optometry, 2011 May;82(5):267-73.
    PMID: 21524597 DOI: 10.1016/j.optm.2011.02.004
    Vision affects daily activities, but of particular importance is the impact upon the learning process. Many studies have been conducted to establish the relationship between vision problems and academic performance. The results are varied, however, and suggest additional research is needed with particular care given to study design.
    Matched MeSH terms: Psychomotor Performance
  15. Manaf H, Justine M, Ting GH, Latiff LA
    Top Stroke Rehabil, 2014 Mar-Apr;21(2):128-36.
    PMID: 24710973 DOI: 10.1310/tsr2102-128
    Little is known about the effects of attentional loading on performance of turning during walking in individuals with stroke.
    Matched MeSH terms: Psychomotor Performance
  16. Saedon NI, Frith J, Goh CH, Ahmad WAW, Khor HM, Tan KM, et al.
    Clin Auton Res, 2020 04;30(2):129-137.
    PMID: 31696333 DOI: 10.1007/s10286-019-00647-3
    PURPOSE: Consensus definitions currently define initial orthostatic hypotension (IOH) as ≥ 40 mmHg systolic (SBP) or ≥ 20 mmHg in diastolic blood pressure (DBP) reductions within 15 s of standing, while classical orthostatic hypotension (COH) is defined as a sustained reduction ≥ 20 mmHg SBP or ≥ 10 mmHg SBP within 3 min of standing. The clinical relevance of the aforementioned criteria remains unclear. The present study aimed to determine factors influencing postural blood pressure changes and their relationship with physical, functional and cognitive performance in older adults.

    METHODS: Individuals aged ≥ 55 years were recruited through the Malaysian Elders Longitudinal Research (MELoR) study and continuous non-invasive BP was monitored over 5 min of supine rest and 3 min of standing. Physical performance was measured using the timed-up-and-go test, functional reach, handgrip and Lawton's functional ability scale. Cognition was measured with the Montreal Cognitive Assessment. Participants were categorized according to BP responses into four categories according to changes in SBP/DBP reductions from supine to standing:

    Matched MeSH terms: Psychomotor Performance/physiology*
  17. Satel J, Hilchey MD, Wang Z, Reiss CS, Klein RM
    Psychophysiology, 2014 Oct;51(10):1037-45.
    PMID: 24976355 DOI: 10.1111/psyp.12245
    Inhibition of return (IOR) operationalizes a behavioral phenomenon characterized by slower responding to cued, relative to uncued, targets. Two independent forms of IOR have been theorized: input-based IOR occurs when the oculomotor system is quiescent, while output-based IOR occurs when the oculomotor system is engaged. EEG studies forbidding eye movements have demonstrated that reductions of target-elicited P1 components are correlated with IOR magnitude, but when eye movements occur, P1 effects bear no relationship to behavior. We expand on this work by adapting the cueing paradigm and recording event-related potentials: IOR is caused by oculomotor responses to central arrows or peripheral onsets and measured by key presses to peripheral targets. Behavioral IOR is observed in both conditions, but P1 reductions are absent in the central arrow condition. By contrast, arrow and peripheral cues enhance Nd, especially over contralateral electrode sites.
    Matched MeSH terms: Psychomotor Performance/physiology
  18. Hasan H, Davids K, Chow JY, Kerr G
    Hum Mov Sci, 2016 Aug;48:102-11.
    PMID: 27155962 DOI: 10.1016/j.humov.2016.04.008
    The purpose of this study was to observe effects of wearing textured insoles and clinical compression socks on organisation of lower limb interceptive actions in developing athletes of different skill levels in association football. Six advanced learners and six completely novice football players (15.4±0.9years) performed 20 instep kicks with maximum velocity, in four randomly organised insoles and socks conditions, (a) Smooth Socks with Smooth Insoles (SSSI); (b) Smooth Socks with Textured Insoles (SSTI); (c) Compression Socks with Smooth Insoles (CSSI) and (d), Compression Socks with Textured Insoles (CSTI). Reflective markers were placed on key anatomical locations and the ball to facilitate three-dimensional (3D) movement recording and analysis. Data on 3D kinematic variables and initial ball velocity were analysed using one-way mixed model ANOVAs. Results revealed that wearing textured and compression materials enhanced performance in key variables, such as the maximum velocity of the instep kick and increased initial ball velocity, among advanced learners compared to the use of non-textured and compression materials. Adding texture to football boot insoles appeared to interact with compression materials to improve kicking performance, captured by these important measures. This improvement in kicking performance is likely to have occurred through enhanced somatosensory system feedback utilised for foot placement and movement organisation of the lower limbs. Data suggested that advanced learners were better at harnessing the augmented feedback information from compression and texture to regulate emerging movement patterns compared to novices.
    Matched MeSH terms: Psychomotor Performance/physiology
  19. Hairol MI, Nordin N, P'ng J, Sharanjeet-Kaur S, Narayanasamy S, Mohd-Ali M, et al.
    PLoS One, 2021;16(3):e0246846.
    PMID: 33657109 DOI: 10.1371/journal.pone.0246846
    Visual-motor integration (VMI) is related to children's academic performance and school readiness. VMI scores measured using the Beery-Bucktenicka Developmental Test of Visual-Motor Integration (Beery-VMI) can differ due to differences in cultural and socioeconomic backgrounds. This study compared the VMI scores of Malaysian preschoolers with the corresponding US norms and determined the association between their VMI scores and socioeconomic factors. A cross-sectional study was conducted among 435 preschoolers (mean age: 5.95±0.47 years; age range: 5.08-6.83 years) from randomly selected public and private preschools. VMI scores were measured using Beery-VMI in the preschools' classrooms. Information on the socioeconomic characteristics of the preschoolers was obtained using a parent-report questionnaire. One sample t-test was used to compare their VMI scores with the corresponding US norms. Multivariate logistic regression models were used to explore the influence of socioeconomic factors on the preschoolers' VMI scores. Overall, Malaysian preschoolers' VMI performance was similar to the US standardized norms (p>0.05). Children from low-income families were twice likely to obtain lower than average VMI scores than those from higher-income families (OR = 2.47, 95%CI 1.05, 5.86). Children enrolled at public preschools were more likely to obtain a lower than average VMI score than those who enrolled at private preschools (OR = 2.60, 95%CI 1.12, 6.06). Children who started preschool at the age of six were more likely to obtain lower than average VMI scores than those who started at an earlier age (OR = 4.66, 95%CI 1.97, 11.04). Low maternal education level was also associated with lower than average VMI score (OR = 2.60, 95%CI 1.12, 6.06). Malaysian preschoolers' Beery-VMI performance compared well to their US counterparts. Some socioeconomic factors were associated with reduced VMI scores. Those from disadvantaged socioeconomic backgrounds are more likely to have reduced VMI performance, potentially adversely affecting their school readiness, cognitive performance, and future academic achievements.
    Matched MeSH terms: Psychomotor Performance/physiology*
  20. Ngen CC, Hassan R
    Int Clin Psychopharmacol, 1990 Jul;5(3):165-71.
    PMID: 2230060
    Zopiclone, a cyclopyrrolone with hypnotic properties was compared with temazepam and placebo in the treatment of insomnia. After a week's washout period, suitable subjects were allocated at random to zopiclone 7.5 mg or temazepam 20 mg or placebo for 2 weeks. Measurements of psychomotor function using the Leed's psychomotor tester and letter cancellation were carried out on day 0, 7 and 14. Sleep latency, duration of sleep and number of times waking during the night were recorded on a sleep diary filled by the subjects nightly. Forty-four subjects completed the trial, 15 taking zopiclone, 16 taking temazepam and 10 taking placebo. Both zopiclone and temazepam had significant hypnotic properties when compared to placebo. Zopiclone increased total sleep time in both weeks of the trial while temazepam increased sleep time in the first week only. There was no significant deterioration in psychomotor performance at the end of both weeks for zopiclone. Critical flicker fusion was significantly increased in subjects on temazepam. There were no abnormalities for both zopiclone and temazepam subjects in the blood picture, renal profile, liver function, urine and ECG before and after the study. Zopiclone is an effective hypnotic comparable to temazepam.
    Matched MeSH terms: Psychomotor Performance/drug effects
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