Mapping of Extracorporeal Space by Vibrotactile Reaction Times: A Far-Left-Side Disadvantage

Perception ◽  
1987 ◽  
Vol 16 (3) ◽  
pp. 283-290 ◽  
Author(s):  
Jane M Pierson-Savage ◽  
John L Bradshaw

Vibrotactile reaction times in normal dextrals were measured for the two hands separately when either hand was located at each of seven possible positions: 90°, 45°, and 15° to the left and right of the chest midline, and at the midline itself (0°). Reaction times for the two hands did not differ and there was no Hand by Position interaction. At 90° left, reaction times were significantly slower than at any other position except 45° right. However, none of the other positions, including 45° right, differed from each other. Performance in this task, therefore, was relatively uniform from 90° right to 45° left, but markedly slower at 90° left. This far-left-side disadvantage may reflect a difficulty (for dextrals) in focussing covert attention in the far-left part of space for a block of trials. Since vibrotactile reaction times are sensitive to attentional factors in normal subjects, the paradigm should allow quantification of the clinical symptoms of the hemineglect syndrome; some preliminary observations of this syndrome with another vibrotactile design are reported.

1989 ◽  
Vol 35 ◽  
pp. 34-47
Author(s):  
Suzanne Paijmans-Hazenberg

In order to test whether reaction times to auditory stimuli can be used as a measurement device for hearing impaired subjects, a criterion test was devel-oped with audiometrically normal subjects. It was hypothesized that these normal subjects would recognize a word in connected speech more slowly in an unfavourable than in a favourable sound-noise ratio. To test this hypothesis a pilot was run with this criterion test, consisting of 65 auditorily presented sentences each with a visually presented target. 25 subjects participated in the research. In one third of the sentences a significant correlation was found between S/N ratio and reaction time. The fact that no significant relationship was found in the other sentences may probably be attributed to a combination of factors like differences in individ-ual reaction times and in concentration, different context factors, but certainly also to the presentation of the targetword prior to the auditory signal. Before this test can be used on a larger scale, certain adaptations will have to be made.


2005 ◽  
Vol 17 (10) ◽  
pp. 1638-1651 ◽  
Author(s):  
Francesca Figliozzi ◽  
Paola Guariglia ◽  
Massimo Silvetti ◽  
Isabelle Siegler ◽  
Fabrizio Doricchi

Peripheral vestibular organs feed the central nervous system with inputs favoring the correct perception of space during head and body motion. Applying temporal order judgments (TOJs) to pairs of simultaneous or asynchronous stimuli presented in the left and right egocentric space, we evaluated the influence of leftward and rightward vestibular rotatory accelerations given around the vertical head-body axis on covert attentional orienting. In a first experiment, we presented visual stimuli in the left and right hemifield. In a second experiment, tactile stimuli were presented to hands lying on their anatomical side or in a crossed position across the sagittal body midline. In both experiments, stimuli were presented while normal subjects suppressed or did not suppress the vestibulo-ocular response (VOR) evoked by head-body rotation. Independently of VOR suppression, visual and tactile stimuli presented on the side of rotation were judged to precede simultaneous stimuli presented on the side opposite the rotation. When limbs were crossed, attentional facilitatory effects were only observed for stimuli presented to the right hand lying in the left hemispace during leftward rotatory trials with VOR suppression. This result points to spatiotopic rather than somatotopic influences of vestibular inputs, suggesting that cross-modal effects of these inputs on tactile ones operate on a representation of space that is updated following arm crossing. In a third control experiment, we demonstrated that temporal prioritization of stimuli presented on the side of rotation was not determined by response bias linked to spatial compatibility between the directions of rotation and the directional labels used in TOJs (i.e., “left” or “right” first). These findings suggest that during passive rotatory head-body accelerations, covert attention is shifted toward the direction of rotation and the direction of the fast phases of the VOR.


2019 ◽  
Vol 4 (6) ◽  
pp. 1482-1488
Author(s):  
Jennifer J. Thistle

Purpose Previous research with children with and without disabilities has demonstrated that visual–perceptual factors can influence the speech of locating a target on an array. Adults without disabilities often facilitate the learning and use of a child's augmentative and alternative communication system. The current research examined how the presence of symbol background color influenced the speed with which adults without disabilities located target line drawings in 2 studies. Method Both studies used a between-subjects design. In the 1st study, 30 adults (ages 18–29 years) located targets in a 16-symbol array. In the 2nd study, 30 adults (ages 18–34 years) located targets in a 60-symbol array. There were 3 conditions in each study: symbol background color, symbol background white with a black border, and symbol background white with a color border. Results In the 1st study, reaction times across groups were not significantly different. In the 2nd study, participants in the symbol background color condition were significantly faster than participants in the other conditions, and participants in the symbol background white with black border were significantly slower than participants in the other conditions. Conclusion Communication partners may benefit from the presence of background color, especially when supporting children using displays with many symbols.


Author(s):  
Melanie C. Steffens ◽  
Inga Plewe

Abstract. The introduction of the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998 ) has stimulated numerous research activities. The IAT is supposed to measure the degree of association between concepts. Instances have to be assigned to these concepts by pressing appropriate keys as quickly as possible. The reaction time difference between certain conditions, termed the IAT effect, is used as an indicator of the degree of the concepts’ association. We tested the hypothesis that the degree of association between one concept (or category) and the instances of the other presented concept also influences reaction times. In our experiment, the instances in the target categories, male and female names, were kept constant. The adjectives in the evaluative categories were manipulated: Either the pleasant adjectives were female-associated and the unpleasant adjectives were male-associated, or vice versa. These stereotypic associations were indeed found to exert a substantial influence on the size of the IAT effect. This finding casts doubt on the assumption that the IAT effect may be interpreted as a pure measure of the degree of association between concepts.


1983 ◽  
Vol 50 (02) ◽  
pp. 563-566 ◽  
Author(s):  
P Hellstern ◽  
K Schilz ◽  
G von Blohn ◽  
E Wenzel

SummaryAn assay for rapid factor XIII activity measurement has been developed based on the determination of the ammonium released during fibrin stabilization. Factor XIII was activated by thrombin and calcium. Ammonium was measured by an ammonium-sensitive electrode. It was demonstrated that the assay procedure yields accurate and precise results and that factor XIII-catalyzed fibrin stabilization can be measured kinetically. The amount of ammonium released during the first 90 min of fibrin stabilization was found to be 7.8 ± 0.5 moles per mole fibrinogen, which is in agreement with the findings of other authors. In 15 normal subjects and in 15 patients suffering from diseases with suspected factor XIII deficiency there was a satisfactory correlation between the results obtained by the “ammonium-release-method”, Bohn’s method, and the immunological assay (r1 = 0.65; r2= 0.70; p<0.01). In 3 of 5 patients with paraproteinemias the values of factor XIII activity determined by the ammonium-release method were markedly lower than those estimated by the other methods. It could be shown that inhibitor mechanisms were responsible for these discrepancies.


1966 ◽  
Vol 53 (4) ◽  
pp. 673-680 ◽  
Author(s):  
Torsten Deckert ◽  
Kai R. Jorgensen

ABSTRACT The purpose of this study was to investigate whether a difference could be demonstrated between crystalline insulin extracted from normal human pancreas, and crystalline insulin extracted from bovine and porcine pancreas. Using Hales & Randle's (1963) immunoassay no immunological differences could be demonstrated between human and pig insulin. On the other hand, a significant difference was found, between pig and ox insulin. An attempt was also made to determine whether an immunological difference could be demonstrated between crystalline pig insulin and crystalline human insulin from non diabetic subjects on the one hand and endogenous, circulating insulin from normal subjects, obese subjects and diabetic subjects on the other. No such difference was found. From these experiments it is concluded that endogenous insulin in normal, obese and diabetic human sera is immunologically identical with human, crystalline insulin from non diabetic subjects and crystalline pig insulin.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gyu-Ho Shin ◽  
Sun Hee Park

Abstract Across languages, a passive construction is known to manifest a misalignment between the typical order of event composition (agent-before-theme) and the actual order of arguments in the constructions (theme-before-agent), dubbed non-isomorphic mapping. This study investigates comprehension of a suffixal passive construction in Korean by Mandarin-speaking learners of Korean, focusing on isomorphism and language-specific devices in the passive. We measured learners’ judgment of the acceptability of canonical and scrambled suffixal passives as well as their reaction times (relative to a canonical active transitive). Our analysis generated three major findings. First, learners uniformly preferred the canonical passive to the scrambled passive. Second, as proficiency increased, the judgment gap between the canonical active transitive and the canonical suffixal passive narrowed, but the gap between the canonical active transitive and the scrambled suffixal passive did not. Third, learners (and even native speakers) spent more time in judging the acceptability of the canonical suffixal passive than they did in the other two construction types. Implications of these findings are discussed with respect to the mapping nature involving a passive voice, indicated by language-specific devices (i.e., case-marking and verbal morphology dedicated to Korean passives), in L2 acquisition.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 552
Author(s):  
Dominika Kozicka ◽  
Paulina Zieleźny ◽  
Karol Erfurt ◽  
Jakub Adamek

Herein we describe the development and optimization of a two-step procedure for the synthesis of N-protected 1-aminomethylphosphonium salts from imides, amides, carbamates, or lactams. Our “step-by-step” methodology involves the transformation of amide-type substrates to the corresponding hydroxymethyl derivatives, followed by the substitution of the hydroxyl group with a phosphonium moiety. The first step of the described synthesis was conducted based on well-known protocols for hydroxymethylation with formaldehyde or paraformaldehyde. In turn, the second (substitution) stage required optimization studies. In general, reactions of amide, carbamate, and lactam derivatives occurred at a temperature of 70 °C in a relatively short time (1 h). On the other hand, N-hydroxymethylimides reacted with triarylphosphonium salts at a much higher temperature (135 °C) and over longer reaction times (as much as 30 h). However, the proposed strategy is very efficient, especially when NaBr is used as a catalyst. Moreover, a simple work-up procedure involving only crystallization afforded good to excellent yields (up to 99%).


2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
William Robeson ◽  
Vijay Dhawan ◽  
Yilong Ma ◽  
David Bjelke ◽  
Claude Margouleff ◽  
...  

Our previous dosimetry studies have demonstrated that for dopaminergic radiotracers,18F-FDOPA and18F-FPCIT, the urinary bladder is the critical organ. As these tracers accumulate in the basal ganglia (BG) with high affinity and long residence times, radiation dose to the BG may become significant, especially in normal control subjects. We have performed dynamic PET measurements using18F-FPCIT in 16 normal adult subjects to determine if in fact the BG, although not a whole organ, but a well-defined substructure, receives the highest dose. Regions of interest were drawn over left and right BG structures. Resultant time-activity curves were generated and used to determine residence times for dosimetry calculations.S-factors were computed using the MIRDOSE3 nodule model for each caudate and putamen. For18F-FPCIT, BG dose ranged from 0.029 to 0.069 mGy/MBq. In half of all subjects, BG dose exceeded 85% of the published critical organ (bladder) dose, and in three of those, the BG dose exceeded that for the bladder. The BG can become the dose-limiting organ in studies using dopamine transporter ligands. For some normal subjects studied with F-18 or long half-life radionuclide, the BG may exceed bladder dose and become the critical structure.


Author(s):  
Ali Asghar Sharifi

Background: The aim of this study was to determine the risk factors for carpal tunnel syndrome and its relationship with the severity of the disease. Methods: A total of 131 patients with clinical symptoms of CTS and 131 normal subjects were enrolled, of whom 121 were female both in the CTS cases and the controls. All cases were electro diagnostically confirmed and assigned to three severity groups. BMI, wrist ratio, shape index, digit index and hand length/height ratio were measured in all participants. Mean values for each item were compared between cases and controls and severity subgroups. A logistic regression analysis was performed to determine independent CTS risk factors. Results: The mean values of BMI, wrist ratio and shape index were significantly higher in all CTS patients and females compared to controls, whereas in males only BMI and wrist ratio were higher. The patients in the mild severity subgroup had a significantly lower age and wrist ratio. BMI, wrist ratio and shape index were found to be independent risk factors of CTS development in all patients and females. Conclusion: Our study showed BMI, wrist ratio and shape index as independent risk factors for CTS. These findings are important anatomically and clinically and these are the risk factors of anatomical malfunction of the wrist in CTS.


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