scholarly journals Repetition-priming effect: a cognitive task for the definition of a clinical assessment

2014 ◽  
pp. 41-46
Author(s):  
Silvia Pagani ◽  
Michela Balconi ◽  
Matteo Sozzi ◽  
Stefania Bianchi-Marzoli ◽  
Lisa Melzi ◽  
...  
Keyword(s):  
Cognitive Task ◽  
Facilitatory Effect ◽  
Response Accuracy ◽  
Anova Analysis ◽  
Prime Duration ◽  
Behavioral Measures ◽  
Experimental Conditions ◽  
Experimental Subjects ◽  
Definition Of ◽  
Repetition Priming Effect

This research aims to study how semantic priming words can influence behavioral measures (RTs, accuracy), to develop an experimental paradigm to differentiate visual neglect and hemianopia. 69 experimental subjects were involved in four experiments. In each experiment target words were preceded by word primes semantically related, neutral or unrelated to the target. The four experiments differed in terms of: number of prime, prime duration and distance between pc monitor and subject. In general, related primes should improve facilitatory effect in target recognition more than unrelated primes, reducing RTs and increasing response accuracy. After repeated ANOVA analysis applied to each experiment and paired comparisons, it is possible to point out that single related primes, shown for 150 ms, greatly improve response behavior in terms of RTs reduction. For future applications to the clinical field, we assume that neglect patients should be facilitated in these specific experimental conditions, due to implicit contralesional prime processing. On the contrary, hemianopics should nowise be facilitated, due to visual field deficit.

Articulatory Behavior Pre and Post Full-Mouth Tooth Extraction and Alveoloplasty

1980 ◽  
Vol 23 (3) ◽  
pp. 630-645 ◽  
Author(s):  
Gerald Zimmermann ◽  
J.A. Scott Kelso ◽  
Larry Lander
Keyword(s):  
Control Subject ◽  
High Speed ◽  
Tooth Extraction ◽  
Kinematic Parameters ◽  
Experimental Conditions ◽  
Mean Values ◽  
Articulatory Movements ◽  
The Mean ◽  
Experimental Subjects ◽  
Normal Speech

High speed cinefluorography was used to track articulatory movements preceding and following full-mouth tooth extraction and alveoloplasty in two subjects. Films also were made of a control subject on two separate days. The purpose of the study was to determine the effects of dramatically altering the structural dimensions of the oral cavity on the kinematic parameters of speech. The results showed that the experimental subjects performed differently pre and postoperatively though the changes were in different directions for the two subjects. Differences in both means and variabilities of kinematic parameters were larger between days for the experimental (operated) subjects than for the control subject. The results for the Control subject also showed significant differences in the mean values of kinematic variables between days though these day-to-day differences could not account for the effects found pre- and postoperatively. The results of the kinematic analysis, particularly the finding that transition time was most stable over the experimental conditions for the operated subjects, are used to speculate about the coordination of normal speech.

scholarly journals Caffeine boosts preparatory attention for reward-related stimulus information

2019 ◽  
Author(s):  
Berry van den Berg ◽  
Marlon de Jong ◽  
Marty G. Woldorff ◽  
Monicque M. Lorist
Keyword(s):  
Brain Activity ◽  
Cognitive Task ◽  
Relevant Information ◽  
Caffeine Intake ◽  
Alpha Power ◽  
Behavioral Measures ◽  
Placebo Condition ◽  
Electrical Brain Activity ◽  
Preparatory Attention ◽  
Stroop Stimulus

AbstractBoth the intake of caffeine-containing substances and the prospect of reward for performing a cognitive task have been associated with improved behavioral performance. To investigate the possible common and interactive influences of caffeine and reward-prospect on preparatory attention, we tested 24 participants during a 2-session experiment in which they performed a cued-reward color-word Stroop task. On each trial, participants were presented with a cue to inform them whether they had to prepare for presentation of a Stroop stimulus and whether they could receive a reward if they performed well on that trial. Prior to each session, participants received either coffee with caffeine (3 mg/kg bodyweight) or with placebo (3 mg/kg bodyweight lactose). In addition to behavioral measures, electroencephalography (EEG) measures of electrical brain activity were recorded. Results showed that both the intake of caffeine and the prospect of reward improved speed and accuracy, with the effects of caffeine and reward-prospect being additive on performance. Neurally, reward-prospect resulted in an enlarged contingent negative variation (CNV) and reduced posterior alpha power (indicating increased cortical activity), both hallmark neural markers for preparatory attention. Moreover, the CNV enhancement for reward-prospect trials was considerably more pronounced in the caffeine condition as compared to the placebo condition. These results thus suggest that caffeine intake boosts preparatory attention for task-relevant information, especially when performance on that task can lead to reward.

Determination of the aluminium complexing capacity of fulvic acids and natural waters, with examples from five New Zealand rivers

1996 ◽  
Vol 47 (1) ◽  
pp. 11 ◽  
Author(s):  
DJ Hawke ◽  
KJ Powell ◽  
JE Gregor
Keyword(s):  
Reaction Time ◽  
Natural Waters ◽  
Fulvic Acids ◽  
Operational Definition ◽  
Experimental Conditions ◽  
River Waters ◽  
Complexation Capacity ◽  
Complexing Capacity ◽  
Definition Of

An FIA technique with 7 s reaction time was used to analyse free plus labile Al in fulvic acid (FA) solutions and natural waters at pH 4.7, without the need for separation procedures. Titrations of these solutions using incremental pH or total Al were used to determine pH binding curves or estimates of the 'kinetic' Al complexation capacity (Al-CCk) respectively. The operational definition of Al-CCk relates to the capacity of a humic substance or natural water to bind Al through a 7-s FIA reaction time under defined experimental conditions of chromophore (CAS) concentration, ionic strength, and pH. Both Al binding strength and complexation capacity were greater than the corresponding Cu-CC (ISE) values. The Al-CCk measurements at pH 4.7 were 710 μmol Al g-1 v. 590 μmol Cu g-1. Al-CCk results (pH 4.7) were higher for soil FA (710 μmol g-1) than for aquatic FA (390 μmol g-1). Al-CCk results (pH 4.7) for five unfiltered river waters from different catchments gave results in the range 6.5-9.8 μmol Al L-1. The differences between total (natural) Al in the samples and Al-CCk were between 2.7 μM and 8.6 μM. Filtration experiments identified fractionation patterns between total (natural) Al and the fraction of Al-CCk not utilized. The Al titration of alginate, another component of natural organic matter, is reported.

The Effect of Residence Time on Biomass Pyrolysis of Several in Different Temperature Nodes

2015 ◽  
Vol 733 ◽  
pp. 280-283 ◽  
Author(s):  
Jian Jun Cai ◽  
Qing Cheng Wang ◽  
Quan Wang
Keyword(s):  
Residence Time ◽  
Kinetic Equations ◽  
Interval Length ◽  
Order Kinetic ◽  
Biomass Pyrolysis ◽  
Thermo Gravimetric ◽  
Experimental Conditions ◽  
Thermo Gravimetric Analyzer ◽  
Experimental Subjects ◽  
Typical Temperature

The effect of residence time on biomass pyrolysis is discussed in the paper. Firstly, several typical temperature nodes (573, 873, 1073, and 1273K) are selected as the experimental subjects. Then, the residence time is changed in these temperature nodes. Finally, thermo gravimetric analyzer is used to study the pyrolysis and kinetics characteristics of biomass in different experimental conditions. The results show that extension of residence time is not conducive to biomass mass loss and heat release at 523, 873, 1073, and 1273K. In the several temperature condition that the faster heating rate and the shorter residence time, the more weightlessness is and the phenomenon is more obvious in low temperature. With the increase of the residence time, area and value of the second endothermic peak decreases and the value moves to high temperature zone. When the residence time is not the same value, the biomass pyrolysis can still be fitted for two first-order kinetic equations. At the same time, temperature interval length of fitting curve decreases and further leads to E and A increase.

scholarly journals The Effects of High-Intensity Interval Exercise and Hypoxia on Cognition in Sedentary Young Adults

Medicina ◽  
2019 ◽  
Vol 55 (2) ◽  
pp. 43 ◽  
Author(s):  
Shengyan Sun ◽  
Paul D. Loprinzi ◽  
Hongwei Guan ◽  
Liye Zou ◽  
Zhaowei Kong ◽  
...  
Keyword(s):  
Reaction Time ◽  
Cognitive Function ◽  
High Intensity ◽  
Cognitive Task ◽  
Response Accuracy ◽  
Acute Bout ◽  
Moderate Hypoxia ◽  
Interval Exercise ◽  
Hypoxic Conditions ◽  
High Intensity Interval

Background and Objectives: Limited research has evaluated the effects of acute exercise on cognition under different conditions of inspired oxygenation. Thus, the purpose of this study was to examine the effects of high-intensity interval exercise (HIE) under normoxia (inspired fraction of oxygen (FIO2): 0.209) and moderate hypoxia (FIO2: 0.154) on cognitive function. Design: A single-blinded cross-over design was used to observe the main effects of exercise and oxygen level, and interaction effects on cognitive task performance. Methods: Twenty inactive adults (10 males and 10 females, 19–27 years old) performed a cognitive task (i.e., the Go/No-Go task) before and immediately after an acute bout of HIE under normoxic and hypoxic conditions. The HIE comprised 10 repetitions of 6 s high-intensity cycling against 7.5% body weight interspersed with 30 s passive recovery. Heart rate, peripheral oxygen saturation (SpO2) and rating of perceived exertion were monitored. Results: The acute bout of HIE did not affect the reaction time (p = 0.204, η2 = 0.083) but the accuracy rate decreased significantly after HIE under both normoxic and hypoxic conditions (p = 0.001, η2 = 0.467). Moreover, moderate hypoxia had no influence either on reaction time (p = 0.782, η2 = 0.004) or response accuracy (p = 0.972, η2 < 0.001). Conclusions: These results indicate that an acute session of HIE may impair response accuracy immediately post-HIE, without sacrificing reaction time. Meanwhile moderate hypoxia was found to have no adverse effect on cognitive function in inactive young adults, at least in the present study.

Metacognition, cognition and learning: Old dubitations and new directions

1994 ◽  
Vol 7 ◽  
pp. 18-31
Author(s):  
Graham Davidson
Keyword(s):  
Task Performance ◽  
Test Performance ◽  
Cultural Context ◽  
Cognitive Task ◽  
Cultural Groups ◽  
Cultural Research ◽  
New Directions ◽  
Level Of Knowledge ◽  
Cognition And Learning ◽  
Definition Of

Research into metacognition, a relatively new construct in the cognitive sciences, has been prodigious over the last decade. This is despite continuing doubts about its heuristic value. Initial doubts emphasised difficulties associated with definition of the construct, the limited predictive power of metacognitive task performance in relation to actual cognitive task or test performance and, relatedly, difficulties in operationalising the construct in specific thinking and problem solving contexts. Subsequent cross-cultural research has focussed on the degree to which metacognitive thinking is situationalised according to cultural context and thinking task, despite the implication that such thinking, by nature, is “multicontextual.” It then questioned the extent to which different social and cultural groups differ in their construction of the metacognitive level of knowledge and its relevance to their everyday life task performance and thinking.

Lipid Peroxidation. Definition of Experimental Conditions for Selective Study of the Propagation and Termination Phases

1989 ◽  
Vol 5 (4-5) ◽  
pp. 245-252 ◽  
Author(s):  
Bruna Tadolini ◽  
Diana Fiorentini ◽  
Laura Landi ◽  
Luciana Cabrini
Keyword(s):  
Lipid Peroxidation ◽  
Experimental Conditions ◽  
Definition Of

The Importance of Handwriting Experience on the Development of the Literate Brain

2017 ◽  
Vol 26 (6) ◽  
pp. 502-508 ◽  
Author(s):  
Karin H. James
Keyword(s):  
Young Children ◽  
Visual Processing ◽  
Functional Neuroimaging ◽  
Letter Recognition ◽  
Facilitatory Effect ◽  
Symbol Recognition ◽  
Facilitative Effect ◽  
Behavioral Measures ◽  
Motor Systems ◽  
The Brain

Handwriting experience can have significant effects on the ability of young children to recognize letters. Why handwriting has this facilitative effect and how this is accomplished were explored in a series of studies using overt behavioral measures and functional neuroimaging of the brain in 4- to 5-year-old children. My colleagues and I showed that early handwriting practice affects visual symbol recognition because it results in the production of variable visual forms that aid in symbol understanding. Further, the mechanisms that support this understanding lay in the communication between visual and motor systems in the brain: Handwriting serves to link visual processing with motor experience, facilitating subsequent letter recognition skills. These results are interpreted in the larger context of the facilitatory effect that learning through action has on perceptual capabilities.

Effect of ethanol on the glucose-induced movements of protons across the plasma membrane of Saccharomyces cerevisiae NCYC 431

1987 ◽  
Vol 33 (2) ◽  
pp. 93-97 ◽  
Author(s):  
Jean-Regis Juroszek ◽  
Michel Feuillat ◽  
Claudine Charpentier
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Ethanol Tolerance ◽  
Ethanol Concentration ◽  
Effect Of Temperature ◽  
Proton Efflux ◽  
Experimental Conditions ◽  
Growth Cessation ◽  
A New Technique ◽  
Definition Of

The study of glucose-induced proton fluxes in Saccharomyces cerevisiae NCYC 431 showed a decrease of proton net efflux by ethanol across the plasma membrane of energized cells. Furthermore a negative net proton efflux (an influx) occurred from a given ethanol concentration (between 1.3 and 1.5 M) whatever the experimental conditions used, thus allowing the definition of a nil–net exchange step where no net movement of protons across the plasma membrane could be observed. A new technique of ethanol tolerance determination in yeast based upon a correlation for the same ethanol concentration between both the collapse of the proton gradient and the growth cessation in cultures supplemented with ethanol after 8 h incubation was proposed. The defined method also showed a cumulated effect of temperature and ethanol on Saccharomyces cerevisiae NCYC 431.

Contrast analysis of the composition of ribosomes extracted with different purification procedures

2000 ◽  
Vol 33 (4) ◽  
pp. 1113-1118 ◽  
Author(s):  
Giuseppe Briganti ◽  
Rita Giordano ◽  
Paola Londei ◽  
Francesco Valle
Keyword(s):  
Particle Density ◽  
Buoyant Density ◽  
Bulk Water ◽  
Water Molecules ◽  
Experimental Conditions ◽  
Reliable Technique ◽  
E Coli ◽  
Contrast Analysis ◽  
Definition Of ◽  
Contour Surface

The composition and hydration ofE. coliribosomes isolated with different purification protocols has been analysed by combining two experimental techniques: measurements of small-angle neutron scattering (SANS), for two different isotopic solvent compositions, and refractive index (RI) increments. From the contrast between the solvent and solute scattering densities and the molar polarizability, determined experimentally with SANS and RI measurements, three independent equations are obtained and three unknown quantities are determined: (i) the volume of the solute hydrated skeletonVs, (ii) the material contained in it, namely the biological components, intrinsic (rRNA and proteins) and extrinsic, such as aminoacylsynthetase and elongation factors, (iii) the number of water molecules structurally bound to the ribosome and non-exchangeable with the solvent. From the form factor at infinite contrast, a second definition of the solute volume is obtained, V_s^c, which represents the volume within the contour surface of the ribosome. This value is generally larger thanVsand can include a certain amount of water molecules,i.e.those inside the volume (V_s^c −Vs). Considering the molar volume of this water to be equal to that of the bulk water, it is possible to evaluate its amount. The particle density calculated from the ribosome components in V_s^c, including proteins, RNA, bound and unbound water molecules, corresponds to the buoyant density measured forE. coli70S particles. The two ribosomal preparations display different performances in protein synthesis; hence the results indicate that the optimal condition corresponds to a wider skeleton and contour volume but containing a smaller amount of segregated water molecules. It is believed that the method provides a reliable technique to determine the composition of ribosomes under various experimental conditions.

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