Increase In Response Speed Research Articles

Effect of Li/Nb ratio on structure and photorefractive properties of Zn:Fe:LiNbO3 crystals

Zn:Fe:LiNbO3 crystals with different Li/Nb ratios in the melts (Li/Nb = 0.946, 0.97, 1.00, 1.10, 1.20, 1.44) have been grown for the first time. The UV–Vis absorption spectra, exponential gain coefficient, diffraction efficiency and response time of the crystals were measured. With the ratio of Li/Nb increasing, the absorption edge shifts to a shorter wavelength, the exponential gain coefficient and response speed increase, but the diffraction efficiency decreases.

Preparation and oxygen-sensing properties of TiO 2 porous thin films on alumina substrate

The titanium dioxide sols were synthesized with tetrabutyl titanate as precursor, diethanolamine(DEA) as complexing agent, polyethylene glycol (PEG) as organic template. The porous films were prepared by sol-gel method. The structures and morphology of the titanium dioxide porous films were characterized by FE-SEM. The formation mechanism of TiO 2 porous films and the relation between the porous structure and oxygen-sensing properties of TiO 2 films were studied. Ordered structure was formed by assembling between TiO 2 colloid particles and the template molecules. PEG molecules acted on TiO 2 colloid particles by hydrogen bond and bridge oxygen. The porous structure was formed after the organic template was decomposed when calcining the films. The diameter, amount and distribution of the pores in the films are related with the content of PEG. The pore diameter increases with increasing of content of PEG and the pore density reaches the maximum at certain content. Oxygen-sensitivity and response speed of porous TiO 2 films are improved compared with films without pores. Both the sensitivity and response speed increase with the increasing of pore diameter and pore density. Oxygen-sensitivity reaches 3 order of magnitude at 800 °C. Its response time from H 2/N 2 to O 2/N 2 atmosphere and vice versa is about 0.11 s and 0.12 s respectively. Although the sensitivity and response speed increase, the resistance-temperature properties of porous films are not notably improved with the increasing of the content of PEG.

The spatial distribution of visual attention in hemineglect and extinction patients.

We studied the visual field distribution of speed and accuracy of manual responses to small brief light flashes, in patients with left hemineglect or extinction resulting from right hemisphere vascular lesions and in brain-damaged and healthy control subjects. All patients with right hemisphere lesions showed a greater impairment in both the speed of response and the detection rate in the contralesional than in the ipsilesional hemifield. This interfield difference increased with the eccentricity of stimulus presentation and was especially pronounced in neglect patients who showed a paradoxical increase in speed of response and detection rate at increasingly larger eccentricities in the ipsilesional hemifield. We hypothesize that both the contralesional slowing down and the ipsilesional speeding up of the response depends upon an exaggerated gradient of attention towards the ipsilesional hemifield. To assess whether these abnormalities concern automatic or controlled attentional processes, in a second experiment, we manipulated the predictability of the side of the stimulus presentation by using blocked rather than randomized stimulus presentations. This resulted in a speeding up of responses in both hemifields thus showing that the patients were able to focus attention to the side of stimulus presentation voluntarily. However, there was no modification of the contra-ipsilesional differences which, therefore, are likely to be related to abnormal automatic processes rather than controlled attention.

Response speed on aptitude tests as an index of intellectual performance: A developmental perspective

The development of mental speed has been studied extensively in recent research, but its consequences on individual differences in intelligence are still largely unknown. We examine this issue here, with an index of mental speed measured from computerized aptitude tests items. This index of mental speed rallies three methodological controls (separate measures of speed and level of ability, control for the correctness of the response and for the item's difficulty), which permit one to go beyond the confusion that has reigned in psychometric studies of mental speed and to bypass most of the criticisms that have been addressed recently to elementary cognitive tasks. Our results show an increase in response speed from the age of 9 to 11 years and a strong correlation between speed and mental age. We also observed an increase, from the ages of 9 to 11, in the correlation between speed and IQ. In conclusion, we explore the hypothesis of a transformation, with age, of the combination of processes that are involved in performance. This transformation would be comparable to automatization.

Part-Task vs. Whole-Task Training on a Supervisory Control Task

The primary aim of training is to improve performance. Part-task training may be the more economical method, because full mission training simulators often cost more than the vehicles they simulate. However, the skills learned may not transfer effectively to performance of the complete task. This study investigated the effectiveness of Part-task training on the psychomotor portion of a supervisory control simulation. Twelve subjects were divided into Part-task and Whole-task groups and told to perform the task as quickly as possible. Part-task training was provided with the cursor-control device (a magnetic pen and pad), prior to transition to the Whole-task. Some distinct advantages of the Part-task training were: (1) The Part-task group learned the task faster; (2) The Part-task group's scores and task times continued to improve, while the Whole-task group's did not; and (3) A significant increase in speed of response for the Part-task group and almost no improvement in speed for the Whole-task group.

Intelligence, sex and psychomotor performance

This experiment investigated the effect of intelligence and sex on two simple psychomotor performance tests—Backward Figure Writing (BFW) and Backward Alphabet Writing (BAW) in 180 high-school students (90 boys and 90 girls). Three levels of intelligence, high, medium and low were taken. Ss being first matched on Extraversion and Neuroticism. Each S worked for 5 min in pre-test period, rested for 1 min and again worked for 2 min in post-rest period. Results indicated that in pre- and post-rest BFW, increase in speed of response was a direct function of increase in intelligence. Similar results were obtained in pre-rest BAW. In post-rest BAW, however, highest performance scores were obtained by the group, average in intelligence, followed by high and low intelligence groups. Sex did not emerge as a significant determiner of performance in BFW. In BAW, means favoured boys in both pre- and post-rest conditions and the F-ratio for sex emerged significant in post-rest BAW only. None of the interactions emerged as significant. The comparison of effects in two independent variables indicated the task-specific nature of various psychomotor tasks.

Further studies of reversal learning with singly presented stimuli in pigeons and goldfish

The performance of pigeons and goldfish was studied in a series of discrete-trial red-green discrimination reversals, with stimuli presented singly and the time of response to each measured. Both animals showed progressive improvement, but it took different forms. In the pigeons, there was a decline over reversals in the temporal stability of inhibition and an increase in the rate of inhibitory development. In the goldfish, there was a general increase in speed of response to the positive stimulus. The results are compared with those obtained in previous experiments.

The effects of incentive shift as a function of training

Five groups of rats were trained and extinguished in an 11 ft runway. Either 0, 10, 20, 30, or 40 trials were given with 1 Noyes pellet followed by the remainder of 40 trials with 10 pellets. The increase in response speed following the incentive shift was positively related to the number of 1-pellet trials. Speed during extinction was monotonie with terminal acquisition speed.