Major depressive disorder (MDD) is a serious mental illness with a multifactorial aetiology that was shown to influence behaviour and affect cognition. Previous research has favoured the involvement of dopamine in the aetiology of the disorder, and since one of the critical regulators of the dopamine levels and activity in the brain is DAT1, the present study investigated the association of a single nucleotide polymorphism in the DAT1gene (rs40184) and MDD in the Malaysian population. A total of 300cases and 300 matched controls were recruited from four Klang valley hospitals and were screened for DAT1rs40184 using high resolution melting assays. The allele and genotype frequencies were analysed by using Chi-square. Hardy Weinberg equilibrium for the distribution of alleles and genotypes was tested by using Chi-square. Determination of the association between rs40184 and MDD was achieved by conditional logistic regression using SPSS. In the present study, no significant association was obtained between DAT1and MDD in the Malaysianpopulation.
Age at onset (AAO) is a known prognostic indicator for schizophrenia and is hypothesized to correlate with cognition and symptom severity. TCF4 and AKT1 are schizophrenia risk genes involved in cognitive functions. The current study examined the interactive effects of TCF4 and AKT1 variants with gender, family history of psychiatric disorders and ethnicity on the AAO of schizophrenia.
The early detection of poststroke dementia (PSD) is important for medical practitioners to customize patient treatment programs based on cognitive consequences and disease severity progression. The aim is to diagnose and detect brain degenerative disorders as early as possible to help stroke survivors obtain early treatment benefits before significant mental impairment occurs. Neuropsychological assessments are widely used to assess cognitive decline following a stroke diagnosis. This study reviews the function of the available neuropsychological assessments in the early detection of PSD, particularly vascular dementia (VaD). The review starts from cognitive impairment and dementia prevalence, followed by PSD types and the cognitive spectrum. Finally, the most usable neuropsychological assessments to detect VaD were identified. This study was performed through a PubMed and ScienceDirect database search spanning the last 10 years with the following keywords: "post-stroke"; "dementia"; "neuro-psychological"; and "assessments". This study focuses on assessing VaD patients on the basis of their stroke risk factors and cognitive function within the first 3 months after stroke onset. The search strategy yielded 535 articles. After application of inclusion and exclusion criteria, only five articles were considered. A manual search was performed and yielded 14 articles. Twelve articles were included in the study design and seven articles were associated with early dementia detection. This review may provide a means to identify the role of neuropsychological assessments as early PSD detection tests.
The complex pathophysiology of traumatic brain injury, its cascading effects and a varied outcome suggest that factors such as genetics may permeate and modulate the neurocognitive outcomes in patients with mild traumatic brain injury (mTBI). This study was conducted to determine the relationship between genetic polymorphism of apolipoprotein E, and neurocognitive and functional outcomes in mTBI. Twenty-one patients with mTBI were recruited prospectively. The severity of the injury was established with the Glasgow Coma Score (GCS). Other assessments included the CT Scan of the head on admission, Disability Rating Scale, Chessington Occupational Therapy Neurological Assessment (COTNAB) and Glasgow Outcome Scale (GOS). The Spearmen correlation analysis of ApoE allele status and the cognitive and functional assessments saw some association with the Sensory Motor Ability - Coordination (-0.526, p
Childhood brain injury is an important and complicated public health issue worldwide. Extensive work has been done in this field. This review highlights issues that are frequently misinterpreted or overlooked in the management of childhood brain injury. The incidence of traumatic brain injury is higher than non-traumatic brain injury. However it is frequently over-reported due to various confounding factors. In ascertaining the severity of injury, assessment of brainstem functions is important and should be included in routine clinical assessment. Most rehabilitative efforts are usually aimed at improving the physical outcome. However, non-physical sequelae are also common and may be more disabling with significant impact on the learning and functioning of the child. These areas, which include depression, cognitive functioning and health-related quality of life of children, should not be overlooked in the management of childhood brain injury. In addition to caregiver’s stress, family dynamic and siblings’ well-being also play a crucial role in the recovery process of the child. By highlighting the frequently missed issues in the management of childhood brain injury, it is hoped that clinicians and professionals could pay more attention to these issues and provide a comprehensive medical care for the patients and their families.
Environmental enrichment (EE) is a process of brain stimulation by modifying the surroundings, for example, by changing the sensory, social, or physical conditions. Rodents have been used in such experimental strategies through exposure to diverse physical, social, and exploration conditions. The present study conducted an extensive analysis of the existing literature surrounding the impact of EE on dementia rodent models. The review emphasised the two principal aspects that are very closely related to dementia: cognitive function (learning and memory) as well as psychological factors (anxiety-related behaviours such as phobias and unrealistic worries). Also highlighted were the mechanisms involved in the rodent models of dementia showing EE effects. Two search engines, PubMed and Science Direct, were used for data collection using the following keywords: environmental enrichment, dementia, rodent model, cognitive performance, and anxiety-related behaviour. Fifty-five articles were chosen depending on the criteria for inclusion and exclusion. The rodent models with dementia demonstrated improved learning and memory in the form of hampered inflammatory responses, enhanced neuronal plasticity, and sustained neuronal activity. EE housing also prevented memory impairment through the prevention of amyloid beta (Aβ) seeding formation, an early stage of Aβ plaque formation. The rodents subjected to EE were observed to present increased exploratory activity and exert less anxiety-related behaviour, compared to those in standard housing. However, some studies have proposed that EE intervention through exercise would be too mild to counteract the anxiety-related behaviour and risk assessment behaviour deficits in the Alzheimer's disease rodent model. Future studies should be conducted on old-aged rodents and the duration of EE exposure that would elicit the greatest benefits since the existing studies have been conducted on a range of ages and EE durations. In summary, EE had a considerable effect on dementia rodent models, with the most evident being improved cognitive function.
The Apolipoprotein E ε4 (APOE ε4) haplotype is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). The Translocase of Outer Mitochondrial Membrane-40 (TOMM40) gene maintains cellular bioenergetics, which is disrupted in AD. TOMM40 rs2075650 ('650) G versus A carriage is consistently related to neural and cognitive outcomes, but it is unclear if and how it interacts with APOE. We examined 21 orthogonal neural networks among 8,222 middle-aged to aged participants in the UK Biobank cohort. ANOVA and multiple linear regression tested main effects and interactions with APOE and TOMM40 '650 genotypes, and if age and sex acted as moderators. APOE ε4 was associated with less strength in multiple networks, while '650 G versus A carriage was related to more language comprehension network strength. In APOE ε4 carriers, '650 G-carriage led to less network strength with increasing age, while in non-G-carriers this was only seen in women but not men. TOMM40 may shift what happens to network activity in aging APOE ε4 carriers depending on sex.
Most neuroscience cognitive experiments involve repeated presentations of various stimuli across several minutes or a few hours. It has been observed that brain responses, even to the same stimulus, evolve over the course of the experiment. These changes in brain activation and connectivity are believed to be associated with learning and/or habituation. In this paper, we present two general approaches to modeling dynamic brain connectivity using electroencephalograms (EEGs) recorded across replicated trials in an experiment. The first approach is the Markovian regime-switching vector autoregressive model (MS-VAR) which treats EEGs as realizations of an underlying brain process that switches between different states both within a trial and across trials in the entire experiment. The second is the slowly evolutionary locally stationary process (SEv-LSP) which characterizes the observed EEGs as a mixture of oscillatory activities at various frequency bands. The SEv-LSP model captures the dynamic nature of the amplitudes of the band-oscillations and cross-correlations between them. The MS-VAR model is able to capture abrupt changes in the dynamics while the SEv-LSP directly gives interpretable results. Moreover, it is nonparametric and hence does not suffer from model misspecification. For both of these models, time-evolving connectivity metrics in the frequency domain are derived from the model parameters for both functional and effective connectivity. We illustrate these two models for estimating cross-trial connectivity in selective attention using EEG data from an oddball paradigm auditory experiment where the goal is to characterize the evolution of brain responses to target stimuli and to standard tones presented randomly throughout the entire experiment. The results suggest dynamic changes in connectivity patterns over trials with inter-subject variability.
Traumatic brain injury (TBI) is a leading cause of death and disability in individuals worldwide. Producing a clinically relevant TBI model in small-sized animals remains fairly challenging. For good screening of potential therapeutics, which are effective in the treatment of TBI, animal models of TBI should be established and standardized. In this study, we established mouse models of closed head injury using the Shohami weight-drop method with some modifications concerning cognitive deficiency assessment and provided a detailed description of the severe TBI animal model. We found that 250 g falling weight from 2 cm height produced severe closed head injury in C57BL/6 male mice. Cognitive disorders in mice with severe closed head injury could be detected using passive avoidance test on day 7 after injury. Findings from this study indicate that weight-drop injury animal models are suitable for further screening of brain neuroprotectants and potentially are similar to those seen in human TBI.
Athletes born at the beginning of the year may present advantages in terms of physical characteristics, motor ability or cognitive knowledge that could increase their chances for selection against their peers. This circumstance could lead to the over-representation of older athletes in an age-defined competition, a phenomenon commonly referred to as relative age effect (RAE). Although, a number of studies have demonstrated that RAE is apparent in youth soccer, such studies rarely investigate the performance advantage that likely exists across the birth month of the athletes. The current study aims to determine the presence of RAE in the under 16 Asian Football Confederation Championship (AFC); investigate the effect of RAE on the team qualification success; as well as ascertain the existence of RAE in choice of playing position amongst the soccer players. Data for the 2018 AFC under 16 qualifications matches were obtained from the AFC. A total of 719 players from 32 countries participated in the qualification competitions. Chi-square for goodness fit is used to determine the existence of the RAE across the players’ month of birth while logistic regression is applied to analyze the differences of the quartiles’ distribution with respect to the quartile, qualification status (qualifier or non-qualifier) as well as the playing position of the players. The results demonstrate the presence of RAE in the AFC under 16 soccer tournaments [χ2(4) = 21.53; p < 0.001] with the largest number of older players dominating the qualified team. Likewise, a substantial difference is observed with regards to the quartile and various playing positions of the players at p < 0.05.
Currently, great emphasis is placed on the development and intervention of psychology in sports in order to address the problem of athletes’ failure to achieve peak performance in actual competitions. This problem is primarily due to internal factors, such as anxieties, as well as external factors, such as the high pressure of the competitive environments athletes encounter. In this study, the cognitive anxiety, somatic anxiety and self confidence levels amongst elite and sub-elite Malaysian volleyball players are defined (male sample n = 50; female sample n = 35; age range between 17 to 25 years). These parameters were measured using the Competitive State Anxiety Inventory (CSAI-2), in which the questionnaires were completed by all respondents 30 minutes prior to the start of a competition. The findings indicated that there was a significant difference (p < 0.005) in cognitive anxiety, somatic anxiety and self-confidence among elite and sub-elite Malaysian (male and female) volleyball athletes. According to the findings, the competitive anxiety levels of the sub-elite athletes were higher than the elite, mainly due to the inability of the sub-elite athletes to control their emotions using psychological skills. In order to minimize this problem, a novel approach that involves using virtual reality to reduce the athletes’ competitive anxiety was proposed. This approach utilizes a 3D immersive environment that was developed based on the challenging real-world situations encountered during a volleyball match. The design and development of this approach is predicted to enhance athletes’ psychological skills, and in turn ensure that they can achieve peak performance under high pressure conditions.
The purpose of this study is to explore and understand the exercise maintenance in women with breast cancer survivors adopting Guolin Qigong using the Social Cognitive Theory related constructs. A qualitative approach using in-depth interviews were employed in this study. 22 participants of the Malaysia Guolin Qigong Association from five regions in Peninsular Malaysia were purposely selected to participate in this study. Data was collected through a series of audiotapes during the interview sessions. They were asked on how do they maintain in their Guolin Qigong exercise. Three themes related to the Social Cognitive Theory constructs emerged from the data collected. (i) Personal Factors; (ii) Environmental Factors and (iii) Tailored Program. The belief in Guolin Qigong or in an exercise program is crucial in helping one to maintain with the exercise program and this findings is consistent with literature that those responded favourably to an exercise will have greater positive attitudes to exercise maintenance. To keep these women maintain the exercise it is important that these women have friends who understand them better to share their experiences related to their disease. It has been suggested that connecting to other survivors contributes to the survivors' positive well-being and to deal with their everyday living. Lastly, the type of exercise should be tailored to the physical condition of these women to keep them sustain the exercise. This theory can be used by the health practitioners to develop more effective interventions for increasing exercise maintenance in sedentary cancer survivors by taking into special attention personal factors particularly one's beliefs and inner motivation. Having to embark and engage into an exercise program of their preferred choice will help one to maintain an exercise program.
Psychobiological predictors of emotionality were evaluated in relations to complex reaction and movement performances have been considered as the significant aspect of research interest. Considerable research base confirms that the expert players employ more pertinent search strategies, eliminate irrelevant cues which enable them to effectively anticipate action requirements and they have superior ability to use cue-related information to reliably anticipate occurrence of relevant events. Present study was aimed at identification of intricate relationship between the ability of the high performing swimmers (National - level swimmers of Malaysia) in anticipatory cue-utilization and corresponding autonomic phasic skin conductance responses isolated from the tonic measures. Altogether two-hundred and twenty-five individuals having high athletic calibre, and holding top-positions in recently held (within the period March 2011 up to the June 2011) National and International (Mostly ASEAN level) meets volunteered as the participants in this study. Simultaneous evaluation of autonomic arousal modulation (habituation paradigm tonic and phasic measures of skin conductance) was done when the swimmers were engaged in cue-related anticipatory task, associated with complex reaction performance. For this purpose, participants were evaluated intermittently (twice within the calendar year August 2010 - June 2011) with the identical research paradigm. Perceived sense of competence as well as the subjective feelings of apprehension of loosing was explored, and attempts were made to identify the obscure subjective expression of cognitive-emotional make-up, in explaining differential performance outcomes evident in the participants. Findings of multiple linear and polynomial regression analyses however suggested direct, inverse and supportive relationships between decomposition of skin conductance tonic and phasic autonomic components related to cognitive-affective and affective motivational aspects of sports behaviour explaining pathways to both excellent and debilitative performance outcomes during practice sessions as well as in actual competitive situations.
The ability to produce performances at highest level under physically and emotionally demanding conditions underline the worth of a sportsperson. These stressful conditions places demands on the cognitive resources of the sportsperson; especially in anticipatory actions that require the allocation of cognitive resources. This study investigated the effects of cognitive stress on the temporal anticipation of a timing motor task. A repeated measures design was applied with two independent variables; cognitive stress and levels of difficulty, which included easy, intermediate and difficult. Study participants were 18 male and 18 female undergraduates of the Physical Education programme of Universiti Putra Malaysia. The experimental task involved performing a timing motor task across the three levels of difficulty, under two conditions as follows: (i) without cognitive stress, and (ii) under cognitive stress. Cognitive stress was induced via the continuous subtraction of two from a two-digit number. Participants performed the task individually and the sequence of the experimental task was counter-balanced. A two-way within subject ANOVA was
performed to ascertain the effects of cognitive stress on the temporal anticipation of the timing motor task. Data yielded significant difference in means for the stress main effect [Λ = .64, F (1.35) = 19.89, p < 0.05]; and the task main effect [Λ = .84, F (2, 34) = 3.35, p < 0.05]. Post hoc comparisons produced a significant difference in the means of the performance of the timing motor task at all three levels of difficulty. Data showed that cognitive stress had an effect on the temporal anticipation of the timing motor task. These results are explained from attentional and the neuromotor noise perspectives. It was concluded that the significant difference in the performance of the experimental task was due to the competition for intentional resources and the decrease of the signal to noise ratio due to cognitive stress.
Environmental enrichment (EE) is an environmental paradigm encompassing sensory, cognitive, and physical stimulation at a heightened level. Previous studies have reported the beneficial effects of EE in the brain, particularly in the hippocampus. EE improves cognitive function as well as ameliorates depressive and anxiety-like behaviors, making it a potentially effective neuroprotective strategy against neurodegenerative diseases such as Alzheimer's disease (AD). Here, we summarize the current evidence for EE as a neuroprotective strategy as well as the potential molecular pathways that can explain the effects of EE from a biochemical perspective using animal models. The effectiveness of EE in enhancing brain activity against neurodegeneration is explored with a view to differences present in early and late life EE exposure, with its potential application in human being discussed. We discuss EE as one of the non pharmacological approaches in preventing or delaying the onset of AD for future research.
Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder. Approximately, around 2% to 3% percent of the general population experience symptoms of OCD over the course of their lifetime. OCD can lead to economic burden, poor quality of life, and disability. The characteristic features exhibited generally in OCD are continuous intrusive thoughts and periodic ritualized behaviours. Variations in genes, pathological function of Cortico-Striato-Thalamo-Cortical (CSTC) circuits and dysregulation in the synaptic conduction have been the major factors involved in the pathological progression of OCD. However, the basic mechanisms still largely unknown. Current therapies for OCD largely target monoaminergic neurotransmitters (NTs) in specific dopaminergic and serotonergic circuits. However, such therapies have limited efficacy and tolerability. Drug resistance has been one of the important reasons reported to critically influence the effectiveness of the available drugs. Inflammation has been a crucial factor which is believed to have a significant importance in OCD progression. A significant number of proinflammatory cytokines have been reportedly amplified in patients with OCD. Mechanisms of drug treatment involve attenuation of the symptoms via modulation of inflammatory signalling pathways, modification in brain structure, and synaptic plasticity. Hence, targeting inflammatory signaling may be considered as a suitable approach in the treatment of OCD. The present review focuses mainly on the significant findings from the animal and human studies conducted in this area, that targets inflammatory signaling in neurological conditions. In addition, it also focusses on the therapeutic approaches that target OCD via modification of the inflammatory signaling pathways.
Contemporary cognitive training literature suggests that training on an adaptive task produces improvements only in the trained task or near transfer effects. No study has yet systematically explained the mechanism behind improved performance on the N-back. In this study, we first investigated how improvements in an N-back task using eight pairs of phonologically similar words as stimuli occurred by examining error distributions of the task over training sessions. Nineteen participants (non-native English speakers) trained for 20 sessions over 5 weeks. We observed a reduction in false alarms to non-target words and fewer missed target words. Though the absolute number of phonological-based errors reduced as training progressed, the proportion of this error type did not decrease over time suggesting participants increasingly relied on subvocal rehearsal in completing the N-back. In the second experiment, we evaluated if improvements developed during N-back training transferred to tasks that relied on serial order memory using simple span tasks (letter span with phonologically distinct letters, letter span with phonologically similar letters, digit span forward, and digit span backward). Twenty-nine participants trained on the N-back and 16 trained on the Operation Span (OSPAN) for 15 sessions over 4 weeks. Neither group of participants showed improvements on any of the simple span tasks. In the third experiment, 20 participants (16 native English speakers) trained on the N-back for 15 sessions over 4 weeks also showed increasing reliance on subvocal rehearsal as they progressed through training. Self-report strategy use did not predict improvements on the N-back.
In this editorial, the editors briefly introduce the aims of the Special Issue. If the goal of the scientific field of Cognitive Psychology is to improve our understanding of human cognition, then research needs to be conducted on a much broader slice of humanity than it has mostly been doing. The first aim of this Special Issue was to examine cognitive processes in populations that are different from the typical Western young adult samples often used in previously published studies. Studies in this issue therefore included both non-WEIRD participants as well as WEIRD participants who process information using different sensory experiences (e.g., individuals who are deaf). The second aim was to amplify - where possible - the research of scholars from less well-represented regions. The authors of the studies were affiliated with a diverse range of academic institutes and frequently included partnerships between Western and non-Western investigators.
Previous research has suggested that culture influences perception and attention. These studies have typically involved comparisons of Westerners with East Asians, motivated by assumed differences in the cultures' self-concept or position on the individualism-collectivism spectrum. However, other potentially important sources of cultural variance have been neglected, such as differences in traffic directionality shaped by the urban spatial environment (i.e., left-hand vs. right-hand traffic). Thus, existing research may potentially place too much emphasis on self-concepts or the individualism-collectivism dimension in explaining observed cultural differences in cognition. The present study investigated spatial cognition using a Simon task and tested participants from four nations (Australia, China, Germany, and Malaysia) that differ in both cultural orientation (collectivistic vs. individualistic) and traffic directionality (left-hand vs. right-hand traffic). The task used two possible reference frames underlying the Simon effect: a body-centered one based on global stimulus position relative to the screen's center versus an object-centered one based on local stimulus position relative to a context object. As expected, all groups showed a reliable Simon effect for both spatial reference frames. However, the global Simon effect was larger in participants from countries with left-hand traffic. In contrast, the local Simon effect was modulated by differences in cultural orientation, with larger effects in participants from collectivistic cultures. This pattern suggests that both sources of cultural variation, viz. cultural orientation and traffic directionality, contribute to differences in spatial cognition in distinct ways.