Search results for " test"
showing 10 items of 7948 documents
Facilitation of bottom-up feature detection following rTMS-interference of the right parietal cortex
2010
In visual search tasks the optimal strategy should utilize relevant information ignoring irrelevant one. When the information at the feature and object levels are in conflict, un-necessary processing at higher level of object shape can interfere with detection of lower level orientation feature. We explored the effects of inhibitory trains of transcranial magnetic stimulation (rTMS) on the right and left parietal cortex in healthy subjects performing two visual search tasks. One task (Task A) was characterised by an object-to-feature interference. The other task (Task B) was without such interference. We found that rTMS of the right parietal cortex significantly reduced reaction times (RTs)…
A meta-analysis of cognitive performance in melancholic versus non-melancholic unipolar depression
2016
Abstract Background Recently there is increasing recognition of cognitive dysfunction as a core feature of Major Depressive Disorder (MDD). The goal of the current meta-analysis was to review and examine in detail the specific features of cognitive dysfunction in Melancholic (MEL) versus Non-Melancholic (NMEL) MDD. Methods An electronic literature search was performed to find studies comparing cognitive performance in MEL versus NMEL. A meta-analysis of broad cognitive domains ( processing speed , reasoning/problem solving , verbal learning , visual learning , attention/working memory ) was conducted on all included studies (n=9). Sensitivity and meta-regression analyses were also conducted…
Testosterone responses to competition: the opponent’s psychological state makes it challenging
2010
Testosterone (T) increases after competition have typically been attributed to winning, yet there is also evidence that being victorious is not in itself sufficient to provoke a T response. Instead, it has been proposed that T responses are moderated by psychological processes. Here, we investigated whether the opponent's psychological state affected hormonal changes in men competing face to face on a rigged computer task. The results show that, irrespective of outcome, the competition led to increases in heart rate and T levels. We found that the T levels of the participants increased more when their opponents had high self-efficacy and that T levels were not influenced by participants' ow…
The Use of Heart Rate Variability in Assessing Precompetitive Stress in High-Standard Judo Athletes
2012
The objective of this study is to examine the sensitivity to and changes in heart rate variability (HRV) in stressful situations before judo competitions and to observe the differences among judo athletes according to their competitive standards in both official and unofficial competitions. 24 (10 male and 14 female) national- and international-standard athletes were evaluated. Each participant answered the Revised Competitive State Anxiety Inventory (CSAI-2R) and their HRV was recorded both during an official and unofficial competition. The MANOVA showed significant main effects of the athlete's standard and the type of competition in CSAI-2R, in HRV time domain, in HRV frequency domain an…
A computerized system for measuring time perception in human subjects.
1991
We describe an integrated computerized approach to the design, execution and recording of time perception experiments in human subjects. The program is menu driven and runs on an IBM-compatible microcomputer. The method is easy to use, non-obtrusive to the subjects, and flexible enough to allow the investigator to design studies with a wide range of experimental protocols and study parameters. The fact that the results do not depend on proctor bias or subject-proctor interactions are additional advantages. The technique was applied to study the effects of prompt positive feedback on the time perception of normal human subjects who undergo training. The results of this study are reported.
More on magnitude of priming in implicit memory tasks.
2002
The effects of word frequency, length of the word, and type of word Fragment in a fragment-completion test were investigated with 57 undergraduate students, 19–22 years. Priming with better performance on studied than on nonstudied words in this task was greater for low frequency words than for high frequency words and greater for fragments without the first letter than for fragments with the first letter. It was inferred that characteristics of fragments should be considered in any implicit memory task when the magnitude of priming is of interest. In general, word fragment-completion processes appear to be based on sources of information available in visual identification tasks.
Quantifying foot placement variability and dynamic stability of movement to assess control mechanisms during forward and lateral running
2015
Research has indicated that human walking is more unstable in the secondary, rather than primary plane of progression. However, the mechanisms of controlling dynamic stability in different planes of progression during running remain unknown. The aim of this study was to compare variability (standard deviation and coefficient of variation) and dynamic stability (sample entropy and local divergence exponent) in anterior–posterior and medio-lateral directions in forward and lateral running patterns. For this purpose, fifteen healthy, male participants ran in a forward and lateral direction on a treadmill at their preferred running speeds. Coordinate data of passive reflective markers attached …
Evaluation of texture analysis for the differential diagnosis of focal nodular hyperplasia from hepatocellular adenoma on contrast-enhanced CT images
2018
PurposeTo explore the value of CT texture analysis (CTTA) for differentiation of focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA) on contrast-enhanced CT (CECT).MethodsThis is a retrospective, IRB-approved study conducted in a single institution. A search of the medical records between 2008 and 2017 revealed 48 patients with 70 HCA and 50 patients with 62 FNH. All lesions were histologically proven and with available pre-operative CECT imaging. Hepatic arterial phase (HAP) and portal venous phase (PVP) were used for CTTA. Textural features were extracted using a commercially available research software (TexRAD). The differences between textural parameters of FNH and HCA wer…
Implicit memory functioning in schizophrenia: Explaining inconsistent findings of word stem completion tasks
2014
The definitive implicit memory profile of schizophrenia is yet to be clarified. Methodological differences between studies could be the reason for the inconsistent findings reported. In this study, we have examined implicit memory functioning using a word stem completion task. In addition, we have addressed methodological issues related with lexical and perceptual stimuli characteristics, and with the strategy used to calculate priming scores. Our data show similar performance values in schizophrenic patients and healthy controls. Furthermore, we have not detected significant differences in priming between the two groups, even when this parameter was calculated using three different procedu…
Perceptual priming in schizophrenia evaluated by word fragment and word stem completion
2011
Implicit memory seems to be preserved in schizophrenia as a whole, but dissociations between conceptual and perceptual tasks and between accuracy and reaction time measures have appeared. The present research has revealed some methodological limitations in many studies to date that are focused on the study of perceptual implicit memory in schizophrenic patients using accuracy measures. The review of these studies revealed that limitations are related to an inadequate definition of performance and priming measures, a lack of control over the characteristics of the stimuli, and the absence of information on the experimental procedures used in data collection. Moreover, the task used in these …