scholarly journals Increased Signal Complexity Improves the Breadth of Generalization in Auditory Perceptual Learning

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
David J. Brown ◽  
Michael J. Proulx
Keyword(s):  
Perceptual Learning ◽  
Time Course ◽  
Frequency Interval ◽  
Complex Signals ◽  
Perceptual Training ◽  
Standard Interval ◽  
Effective Training ◽  
Human Adults ◽  
Signal Complexity

Perceptual learning can be specific to a trained stimulus or optimally generalized to novel stimuli with the breadth of generalization being imperative for how we structure perceptual training programs. Adapting an established auditory interval discrimination paradigm to utilise complex signals, we trained human adults on a standard interval for either 2, 4, or 10 days. We then tested the standard, alternate frequency, interval, and stereo input conditions to evaluate the rapidity of specific learning and breadth of generalization over the time course. In comparison with previous research using simple stimuli, the speed of perceptual learning and breadth of generalization were more rapid and greater in magnitude, including novel generalization to an alternate temporal interval within stimulus type. We also investigated the long term maintenance of learning and found that specific and generalized learning was maintained over 3 and 6 months. We discuss these findings regarding stimulus complexity in perceptual learning and how they can inform the development of effective training protocols.

Time-course of treatment-emergent adverse events in a long-term safety study of lisdexamfetamine dimesylate in children and adolescents with ADHD

2016 ◽  
Vol 33 (S1) ◽  
pp. S132-S132
Author(s):  
I. Hernández Otero ◽  
T. Banaschewski ◽  
P. Nagy ◽  
C.A. Soutullo ◽  
A. Zuddas ◽  
...  
Keyword(s):  
Adverse Events ◽  
Children And Adolescents ◽  
Time Course ◽  
Open Label ◽  
Lisdexamfetamine Dimesylate ◽  
Safety Population ◽  
First Onset ◽  
Stimulant Medications ◽  
Competing Interest

IntroductionThe long-term safety and efficacy of lisdexamfetamine dimesylate (LDX) in children and adolescents with attention deficit/hyperactivity disorder (ADHD) was evaluated in a European 2-year, open-label study (SPD489-404).ObjectiveTo evaluate the time-course of treatment-emergent adverse events (TEAEs) in SPD489-404.MethodsParticipants aged 6–17 years received open-label LDX (30, 50 or 70 mg/day) for 104 weeks (4 weeks dose-optimization; 100 weeks dose-maintenance).ResultsAll enrolled participants (n = 314) were included in the safety population and 191 (60.8%) completed the study. TEAEs occurred in 282 (89.8%) participants; most were mild or moderate. TEAEs considered by the investigators as related to LDX were reported by 232 (73.9%) participants with the following reported for ≥ 10% of participants: decreased appetite (49.4%), weight decreased (18.2%), insomnia (13.1%). TEAEs leading to discontinuation and serious TEAEs occurred in 39 (12.4%) and 28 (8.9%) participants, respectively. The median (range) time to first onset and duration, respectively, of TEAEs identified by the sponsor as being of special interest were: insomnia (insomnia, initial insomnia, middle insomnia, terminal insomnia), 17.0 (1–729) and 42.8 (1–739) days; weight decreased, 29.0 (1–677) and 225.0 (26–724) days; decreased appetite, 13.5 (1–653) and 169.0 (1–749) days; headache, 22.0 (1–718) and 2.0 (1–729) days. Reports of insomnia, weight decreased, decreased appetite and headache were highest in the first 4–12 weeks.ConclusionsTEAEs associated with long-term LDX treatment were characteristic of stimulant medications, with the greatest incidence observed during the first 4–12 weeks.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Time Course of Expression of “Early” Genes during Long-Term Posttetanic Potentiation in Rat Hippocampal CA1 Field

2009 ◽  
Vol 148 (3) ◽  
pp. 416-418 ◽  
Author(s):  
O. O. Sokolova ◽  
M. B. Shtark ◽  
P. D. Lisachev ◽  
V. O. Pustyl’nyak ◽  
I. V. Pan
Keyword(s):  
Time Course ◽  
Posttetanic Potentiation ◽  
Early Genes ◽  
Hippocampal Ca1 ◽  
Hippocampal Ca1 Field

scholarly journals Central Insulin Signaling Is Attenuated by Long-Term Insulin Exposure via Insulin Receptor Substrate-1 Serine Phosphorylation, Proteasomal Degradation, and Lysosomal Insulin Receptor Degradation

Endocrinology ◽  
2010 ◽  
Vol 151 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Christopher M. Mayer ◽  
Denise D. Belsham
Keyword(s):  
Insulin Resistance ◽  
Insulin Receptor ◽  
Insulin Signaling ◽  
Time Course ◽  
Proteasomal Degradation ◽  
Serine Phosphorylation ◽  
Neuronal Function ◽  
Protein Levels ◽  
Phosphorylated Akt

Abstract Central insulin signaling is critical for the prevention of insulin resistance. Hyperinsulinemia contributes to insulin resistance, but it is not yet clear whether neurons are subject to cellular insulin resistance. We used an immortalized, hypothalamic, clonal cell line, mHypoE-46, which exemplifies neuronal function and expresses the components of the insulin signaling pathway, to determine how hyperinsulinemia modifies neuronal function. Western blot analysis indicated that prolonged insulin treatment of mHypoE-46 cells attenuated insulin signaling through phospho-Akt. To understand the mechanisms involved, time-course analysis was performed. Insulin exposure for 4 and 8 h phosphorylated Akt and p70-S6 kinase (S6K1), whereas 8 and 24 h treatment decreased insulin receptor (IR) and IR substrate 1 (IRS-1) protein levels. Insulin phosphorylation of S6K1 correlated with IRS-1 ser1101 phosphorylation and the mTOR-S6K1 pathway inhibitor rapamycin prevented IRS-1 serine phosphorylation. The proteasomal inhibitor epoxomicin and the lysosomal pathway inhibitor 3-methyladenine prevented the degradation of IRS-1 and IR by insulin, respectively, and pretreatment with rapamycin, epoxomicin, or 3-methyladenine prevented attenuation of insulin signaling by long-term insulin exposure. Thus, a sustained elevation of insulin levels diminishes neuronal insulin signaling through mTOR-S6K1-mediated IRS-1 serine phosphorylation, proteasomal degradation of IRS-1 and lysosomal degradation of the IR.

Anticipatory saccades in sequential procedural learning in monkeys

1996 ◽  
Vol 76 (2) ◽  
pp. 1361-1366 ◽  
Author(s):  
K. Miyashita ◽  
M. K. Rand ◽  
S. Miyachi ◽  
O. Hikosaka
Keyword(s):  
Time Course ◽  
Preceding Paper ◽  
Button Press ◽  
Visually Guided ◽  
Short Term ◽  
Skilled Performance ◽  
Opposite Hand ◽  
Sequential Procedures ◽  
Correct Target

1. In a preceding paper we examined the short-term and long-term processes of learning of sequential procedures in monkeys. We now report that the pattern of eye movements changed along with the long-term learning. 2. The monkey's task was to press five consecutive pairs of target buttons (indicated by illumination) in the correct order for every pair, which the monkey had to find by trial and error (2 x 5 task). The whole sequence was called the "hyperset"; each pair was called the "set." 3. Initially, the saccade toward the correct target occurred after illumination of the targets (visually guided saccade). After sufficient learning, the saccade tended to occur before the target illumination (anticipatory saccade). This was true only for the hyperset that had been learned. 4. The likelihood of anticipatory saccade increased gradually over 20-30 days of practice of the particular hyperset. The time course was similar to how the hand learned (button press latency). 5. The monkeys were required to use the same hand for each hyperset throughout learning, except when we asked them to use the opposite hand. The nearly perfect performance due to the extensive practice was then deteriorated by the use of the opposite hand. We found, in addition, that anticipatory saccades became much less frequent. This finding suggests that critical for the skilled performance was the combination of the eyes and the side of the hand that was used for the practice of a given sequence.

Static and dynamic postural control in long-term microgravity: evidence of a dual adaptation

2001 ◽  
Vol 90 (1) ◽  
pp. 205-215 ◽  
Author(s):  
Guido Baroni ◽  
Alessandra Pedrocchi ◽  
Giancarlo Ferrigno ◽  
Jean Massion ◽  
Antonio Pedotti
Keyword(s):  
Postural Control ◽  
Time Course ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Principal Component ◽  
Movement Analysis ◽  
Trunk Flexion ◽  
Dynamic Movement ◽  
Static Body

The adaptation of dynamic movement-posture coordination during forward trunk bending was investigated in long-term weightlessness. Three-dimensional movement analysis was carried out in two astronauts during a 4-mo microgravity exposure. The principal component analysis was applied to joint-angle kinematics for the assessment of angular synergies. The anteroposterior center of mass (CM) displacement accompanying trunk flexion was also quantified. The results reveal that subjects kept typically terrestrial strategies of movement-posture coordination. The temporary disruption of joint-angular synergies observed at subjects' first in-flight session was promptly recovered when repetitive sessions in flight were analyzed. The CM anteroposterior shift was consistently <3–4 cm, suggesting that subjects could dynamically control the CM position throughout the whole flight. This is in contrast to the observed profound microgravity-induced disruption of the quasi-static body orientation and initial CM positioning. Although this study was based on only two subjects, evidence is provided that static and dynamic postural control might be under two separate mechanisms, adapting with their specific time course to the constraints of microgravity.

scholarly journals Long-term time-course of strength adaptation to minimal dose resistance training: Retrospective longitudinal growth modelling of a large cohort through training records

2021 ◽  
Author(s):  
James Steele ◽  
James Fisher ◽  
Jürgen Giessing ◽  
Patroklos Androulakis-Korakakis ◽  
Milo Wolf ◽  
...  
Keyword(s):  
Public Health ◽  
Resistance Training ◽  
Fixed Effects ◽  
Time Course ◽  
Small Samples ◽  
Strength Development ◽  
Minimal Growth ◽  
Minimal Effective Dose ◽  
Minimal Dose

Objective: Public health guidelines for resistance training typically emphasize a minimal effective dose approach. The intention for such guidelines is that individuals engage in these behaviors over the long-term. However, relatively few studies have examined the longitudinal time-course of strength adaptations to resistance training and those which have typically utilize small samples and/or athletic populations. Further, no studies have employed approaches to incorporate participant level random factors into modelling. Thus, the aim of this study was to examine the time-course of strength development resulting from continued participation in minimal dose resistance training in a large sample through retrospective training records. Methods: Data was available for analysis from 14,690 participants who had undergone minimal dose resistance training (1x/week, single sets to momentary failure of six exercises) with records ranging up to 352 weeks (~6.8 years) in length. Linear-log growth models examining the development of strength over time were fit allowing random intercepts and slopes by participant. In addition, the interaction of sex and age were examined as fixed effects. Results: All models demonstrated a robust linear-log relationship which on the untransformed time scale clearly demonstrated the presence of a plateau in strength development around ~1 year into training after which strength was essentially maintained with minimal growth. Sex and age had minimal interaction effects. Conclusions: Substantial strength gains are possible with the use of a minimal dose resistance training approach. Though, these begin to plateau after ~1 year of training with little impact from sex or age on the emergence of this plateau. It is unclear if this plateau can be overcome through alternative approaches. Considering this, our results support public health recommendations for minimal dose resistance training to induce and maintain strength adaptations in adults.

scholarly journals Changes in blood hemoglobin and blood gases PaO2 and PaCO2 in severe COPD over a three-year telemonitored program of long-term oxygen treatment

2012 ◽  
Vol 7 ◽  
Author(s):  
Roberto W. Dal Negro ◽  
Silvia Tognella ◽  
Luca Bonadiman ◽  
Paola Turco
Keyword(s):  
Time Course ◽  
Blood Gases ◽  
Wilcoxon Test ◽  
Background Information ◽  
First Year ◽  
Oxygen Treatment ◽  
Blood Hemoglobin ◽  
Time Courses ◽  
Severe Copd

Background: Information on the effects of long-term oxygen treatment (LTOT) on blood hemoglobin (Hb) in severe COPD are limited. The aim was to assess blood Hb values in severe COPD, and investigate the time-course of both Hb and blood gas changes during a 3-year telemetric LTOT. Methods: A cohort of 132 severe COPD patients (94 males; 71.4 years ± 8.8 sd), newly admitted to the tele-LTOT program, was investigated. Subjects were divided according to their original blood Hb: group A: <13 g/dL; group B: ≥13<15 g/dL; group C: ≥ 5<16 g/dL; group D: ≥16 g/dL. Blood Hb (g/dL), PaO2 and PaCO2 (mmHg), SaO2 (%), and BMI were measured at LTOT admission (t0), and at least quarterly over three years (t1-t3). Wilcoxon test was used to compare t0 vs. t1 values; linear regression to assess a possible Hb-BMI relationship; ANOVA to compare changes in Hb time-courses over the 3 years. Results: LTOT induced a systematic increase of PaO2, and changes were significant since the first year (from 52.1 mmHg± 6.6sd to 65.1 mmHg± 8.7 sd, p<0.001). Changes in SaO2 were quite similar. Comparable and equally significant trends were seen in all subgroups (p<0.001). PaCO2 dropped within the first year of LTOT (from 49.4 mmHg± 9.1sd to 45.9 mmHg ±7.5 sd, p<0.001): the t0-t1 comparison proved significant (p<0.01) only in subgroups with the highest basal Hb, who showed a further PaCO2 decline over the remaining two years (p<0.001). Hb tended to normalization during LTOT only in subgroups with basal Hb>15 g/dl (ANOVA p<0.001); anemic subjects (Hb<13 g/dl) ameliorated not significantly in the same period (ANOVA = 0.5). Survival was independent of the original blood Hb. Anemia and polyglobulia are differently prevalent in COPD, the latter being the most represented in our cohort. LTOT affected both conditions, but to a different extent and according to different time-courses. The most striking Hb improvement was in polyglobulic patients in whom also PaO2, PaCO2 and SaO2 dramatically improved. In anemic subjects effects were smaller and slower, oxygenation being equally ameliorated by LTOT. Conclusions: LTOT effects on Hb and PaCO2 are regulated by an Hb-dependent gradient which seems independent of the original impairment of blood gases and of effects on oxygenation.

Effect of 5-azacytidine on gene expression in marrow stromal cells

1989 ◽  
Vol 9 (6) ◽  
pp. 2748-2751
Author(s):  
D F Andrews ◽  
J Nemunaitis ◽  
C Tompkins ◽  
J W Singer
Keyword(s):  
Stromal Cells ◽  
Time Course ◽  
Matrix Protein ◽  
Interleukin 1 ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Marrow Stromal Cells ◽  
Necrosis Factor Alpha ◽  
Factor Alpha

When exposed to 5-azacytidine, marrow stromal cells from active long-term marrow cultures and cell lines derived from simian virus 40-transformed stromal cells rapidly upregulated c-abl and interleukin-6 transcripts while downregulating the expression of collagen I, a major matrix protein. Similar effects occurred with interleukin-1 alpha and tumor necrosis factor alpha, although the time course was considerably prolonged.

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