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Attention in athletes of high and low experience engaged in different open skill sports
No full textIn this study were examined differences in attentional style of athletes engaged in two open skill sports requiring high reactivity (karate and volleyball) in groups with high or low experience. 42 healthy men, 24 volleyball players, 12 of High Experience (first division Italian League players whose M age was 28 yr. (SD=5) and 12 of Low Experience (prejunior Italian team athletes whose M age was 19 yr. (SD= 2). and 18 karateka, 9 of High Experience (3rd and 4th dan black belt athletes whose M age was 31 yr., SD=5) and 9 of Low Experience (1st and 2nd dan black belt karateka whose M age was 32 yr., SD=5). Tests involved different types of attention: Alert, Go/No-Go, Divided Attention, and Working Memory. For each one, the reaction time (RT), variability, change in RT, and number of errors were analysed. Karateka of High Experience reacted faster than those of Low Experience on the simple RT test, Alert (M RT: 204 vs 237 msec., p< .01), while on the Divided Attention test, the High Experience subjects performed more poorly and committed more errors (M errors: 4.89 vs 1.44, p <.003). Young volleyball players of Low Experience reacted faster than colleagues of High Experience on the Alert (M RT: 187 vs 210 msec., p<.01) and Divided Attention tests (M RT: 590 vs 688 msec., p<.001) but committed more errors (Divided Attention test, M errors: 6.50 vs 3.08, p<.007). For the Divided Attention and Working Memory tests, correlations were positive among errors, RT, and RT variability but only for volleyball athletes of High Experience, suggesting they showed higher attention and stability in complex reactions than the group with Low Experience. No significant correlations were noted for either group of karateka on complex reactions. Results suggested that the attentional resources were engaged in different ways in the two groups of athletes and, in each group, there were differences between persons of High and Low Experience
Movement related brain macropotentials and skilled motor actions
No full textBackground: Movement Related Brain Macropotentials (MRBMs) are electrical brain potentials occurring before, during and after skilled movements. Specific components of these potentials have been described and it has been reported that they can be recorded also during mental motor imagery and can be influenced by practice. To understand the exact relationship between MRBMs and skilled actions and to verify the hypothesis that motor training could modify MRBMs profile and influence specific components an experiment has been performed in which MRBMs were recorded during the execution of different skilled performance tasks and before and after a period of training. Methods: The experiment has been carried out with 31 healthy male subjects, divided into three groups. Eleven performed the Alert test (A), a simple reaction time test, in which the subject had to press in a precise sequence three keys of a keyboard when a figure appeared on the computer monitor. Ten subjects performed the Choice test (CH), a complex reaction time test, in which they had to press the three keys in a different order when one of two different figures appeared randomly on the screen. Ten subjects performed the Choice test with the addition of a Go/No-Go paradigm (CHNG) in which participants had also to repress an unsuitable response. All subjects were tested before and after 10 days of training. During the trials EEG, EMG and other physiological parameters were recorded. The time of the recorded test was divided into three periods: prestimulus, motor (premotor, motor action, motor completion) and postmotor. Data were collected, averaged and compared by appropriate statistical methods. Results: The time of EMG activation and Reaction Time (RT) were lower in A then in CH and CHNG. Training did not influenced A, but was followed by a significant reduction of RT in CH and CHNG. The profile of MRBMs was different in the motor period in the three tests. The duration of Premotor Potential (PMP), a positive wave recorded in the premotor component of the motor period, increased passing from A to CHNG, but after training, it was reduced only in the CHNG test. During motor action the duration of the negative wave Motor Cortex Potential (MCP) increased from A to CHNG and was reduced after training in all tests. In CHNG training reduced the latency of N1 and N2, the negative peaks recognizable in the MCP profile, and the latency of the Skilled Performance Positivity (SPP), a wave occurring in the postmotor period. Moreover, after training the period preceding the stimulus showed an increase of negativity in the last 200 msec. Conclusions: MRBMs can change their profile in relation to the characteristics of the test and the skilled motor action. The increase of duration and latency of the motor period waves, passing from A to CHNG, can be considered as picture of increased information processing and response selection brain activity. Moreover, training can affect the profile of the waves, reducing their duration and latency, particularly when the performance requires high mental effort. © 2009 by Nova Science Publishers, Inc
Glucocorticoid receptors in human peripheral blood mononuclear cells in relation to explosive performance in elite handball players
No full textTen handball players, members of the Italian National Team (aged 20–25 years), were studied in two sessions corresponding to different performance levels. The first session occurred one week after the end of the regular season of the Italian Handball ederation: it corresponded to the beginning of the training cycle for the European Handball Championship. The second session occurred ten weeks after the first session. During this period, training consisted of 3 weeks of active recovery and 7 weeks
of increasing workload. For each session, jumping performances (maximal height in a single jump, average mechanical power for a 15-s set of consecutive jumps) were evaluated. Venous blood samples were collected in resting conditions immediately before jumping performances to assess cortisol and testosterone plasma concentrations and glucocorticoid receptors (GcR) binding capacity and affinity in peripheral blood mononuclear cells (PBMCs). All the parameters, except GcR binding affinity, increased in the second session. The trends of variation in jumping performances, steroid hormone levels and GcR binding capacity were similar. For testosterone, this agrees with the hypothesis that an adequate
level of this hormone is a prerequisite for improvement in explosive performances. For cortisol, higher GcR binding capacity after 10 weeks of training (with respect to initial values) indicated an upregulation of GcR concomitant with the increase in hormone levels and performances. These findings suggest that the adaptation to training, confirmed by the improvement in performance, is characterized by a high value of GcR binding capacity and that it is mediated, among other factors, by the hormone levels and up-regulation of the receptors
Changes in corticosteroid receptors mRNA expression after a 3-week multidisciplinary treatment programme in fibromialgia patients
No full textCognitive and phisiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects.
No full textBackground
It has been reported that Omega-3 fatty acids may play a role in nervous system
activity and that they improve cognitive development and reference memory-related learning,
increase neuroplasticity of nerve membranes, contribute to synaptogenesis and are involved
in synaptic transmission. The aim of this study was to examine the effects of Omega-3
supplementation on some cognitive and physiological parameters in healthy subjects.
Materials and methods
Subjects were tested at the beginning of the experiment and after
35 days. In this period they were supplemented with Omega-3 polyunsaturated fatty acids.
A group was supplemented with olive oil (placebo). Tests involving different types of attention
were used, i.e. Alert, Go/No-Go, Choice and Sustained Attention. For each test, the reaction
time, the event-related potentials by electroencephalogram (EEG) and the electromyography
(EMG) of the forefinger flexor muscle were recorded. The Profile of Mood States test
(POMS) was also administered.
Results
Blood analyses showed that after Omega-3 supplementation the arachidonic acid/
eicosapentaenoic acid ratio (AA/EPA) was strongly reduced. The mood profile was improved
after Omega-3 with increased vigour and reduced anger, anxiety and depression states. This
was associated with an effect on reactivity with a reduction of reaction time in the Go/
No-Go and Sustained Attention tests. The latency of EMG activation was concomitantly
reduced in the same tests plus Choice. An EEG frequency shift towards the theta and alpha
band were recorded in all the tests after Omega-3.
Conclusion
Omega-3 supplementation is associated with an improvement of attentional and
physiological functions, particularly those involving complex cortical processing. These
findings are discussed in terms of the influence of Omega-3 on the central nervous system
Internal-external motor imagery and skilled motor actions
No full textThe purpose of this study was to analyze the movement-related brain macropotentials (MRBMs) recorded during the executions of two tests of motor imagery: kinaesthetic (internal) and visual (external).Recordings were compared with those obtained performing a GO/NO-GO motor test. The GO test required pressure of three keys of a modified keyboard in sequence when a figure appeared in the computer screen. On No/GO trials no button had to be pressed. Motor imagery tests were an internal or kinaesthetic imagination test (IN MI) on which partecipants imagined performing the pressure of keyboard buttons, avoiding any real movement, and an external or visual imagination test (EX MI) on wich subjects were asked to imagine seeing their finger press the buttons. With the completion of the Movement Imagery Questionnaire, the partecipants were assigned into two groups: high (11) and low (10) capacity of imagination. The experimental data confirm that real motor activity is related to higher amplitude MRBMs than motor imagery. The profile of the waves recorded during internal imagery seems to be related to a higher brain involvement compared to those recorded during external visual imagery; it suggest that the kinaesthetic process of imaginations is more efficient in information processing and motor skill acquisition
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Changes in salivary cortisol and corticosteroid receptor-alpha mRNA expression following a 3-week multidisciplinary treatment program in patients with fibromyalgia
No full textThe aim of the present study was to investigate the effects of a 3-week residential multidisciplinary non-pharmacological treatment program (including individually prescribed aerobic exercise and cognitive-behavioral therapy) on fibromyalgia symptoms and hypothalamic–pituitary–adrenal (HPA) axis function. Salivary and venous blood samples were collected from 12 female patients with fibromyalgia (age: 25–58) the day before and the day after the treatment period: saliva, eight times (every two hours from 0800 to 2200 h); venous blood, at 0800 h. Peripheral blood mononuclear cells (PBMC) were separated and analyzed for glucocorticoid receptor-a (GR-a) mRNA expression by semi-quantitative RT-PCR, while the salivary cortisol concentration was determined by RIA. At the same time, pain and aerobic capacity were evaluated. Aerobic capacity improved at the end of the treatment program. The slope of the regression of salivary cortisol values on sampling time was steeper in all patients after treatment, indicating that the cortisol decline was more rapid. Concomitantly, the area under the cortisol curve ‘with respect to increase’ (AUCi) was higher and there was a significant increase in GR-a mRNA expression in PBMC. The number of positive tender points, present pain, pain area and CES-D score were significantly reduced after the treatment, while the pressure pain threshold increased at most of the tender points. Our findings suggest that one of the active mechanisms underlying the effects of our treatment is an improvement of HPA axis function, consisting in increased resiliency and sensitivity of the stress system probably related to stimulation of GR-a synthesis by the components of the treatment
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