Search Results
Results 551 - 600 of 952
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Stufflebeam S M - - 1998
Recent work has suggested that, in addition to spatial tonotopy, pitch and timbre information may be encoded in the temporal activity of the auditory cortex. Specifically, the post-stimulus latency of the maximal cortical evoked neuromagnetic field (M100 or N1m) is a function of stimulus frequency. We investigated the additional effect ...
Burton H - - 1998
This study demonstrated effects of stimulus order on single-cell responses in the macaque primary and secondary somatosensory and 7b cortical areas. As part of a study of tactile attention, two monkeys (Macaca mulatta) received similar constant amplitude, sinusoidal tactile vibration patterns (125 Hz) at two glabrous skin, hand locations. The ...
Newby E A - - 1998
The effect of the distance between the center of the focus of attention and an unexpected stimulus on detection was examined in two experiments with the use of the inattentional-blindness paradigm [Mack and Rock, 1998 Inattentional Blindness (Cambridge, MA: MIT Press)]. In experiment 1, the closer a stimulus was to ...
Proctor R. W. - - 1997
In a previous study of two-choice reactions, pairings of spatial stimuli with bimanual presses made on a keyboard and verbal stimuli with unimanual aimed movements made on a display screen showed higher set-level compatibility than the opposite pairings; element-level compatibility (i.e., mapping) effects were also larger for the conditions with ...
Rosenberger W F - - 1997
An experimental subject sequentially receives different levels of a stimulus, and data are recorded on response or non-response to the stimulus. To ensure that the subject cannot predict the next stimulus level based on previous stimulus levels, a randomized design, based on a generalized Pólya urn model, is used to ...
Pardue H L - - 1997
The formal definition of sensitivity associates the term with the change in the response of a system for a small change of the stimulus causing the response, i.e., the ratio of the response of a system to the stimulus causing it. One interpretation of sensitivity associates the rate of change ...
Mattes S - - 1997
Three experiments examined whether temporal uncertainty about the delivery of a response stimulus affects response force in a simple reaction time (RT) situation. All experiments manipulated the foreperiod; that is, the interval between a warning signal and the response stimulus. In the constant condition, foreperiod length was kept constant over ...
Weinberger J - - 1997
Research has shown that subliminal presentation of MOMMY AND I ARE ONE (MIO) can help improve adaptive functioning. Two experiments tried to determine whether changes in mood, especially free-response mood, could help explain these findings. In one experiment, 20 men were randomly assigned to receive either a subliminal MIO or ...
Rubichi S - - 1997
We investigated whether the Simon effect depends on the orienting of attention. In Experiment 1, participants were required to execute left-right discriminative responses to 2 patterns that were presented to the left or right of fixation. The 2 patterns were similar, and the discrimination was difficult. A letter at fixation ...
Kamjoo K - - 1997
BACKGROUND: In excitable chemical media, a spiral wave is formed by reentrant excitation around a core and normal propagation away from the core. Whether or not this applies to cardiac muscle is unknown. METHODS AND RESULTS: In six isolated swine ventricular slices, we induced sustained episodes of functional reentry with ...
Harvey E M - - 1997
PURPOSE: To provide normative data on the effect of a central competing stimulus on monocular visual field extent in 3.5- to 9-month-olds and adults, and binocular visual field extent in 11- to 30-month-olds. METHODS: Visual field extent along diagonal meridia was measured in 180 infants and children (N = 30 ...
Hasbroucq T - - 1997
Fluvoxamine is a specific serotonin reuptake inhibitor. Recent evidence suggests that this antidepressive drug shortens the reaction time (RT) of healthy volunteers. The first objective of the present study was to decipher whether this effect is due to an improvement in information processing per se or to the adoption of ...
Svensson P - - 1997
To study the role of the mossy fiber afferents to the cerebellum in classical eye-blink conditioning, in particular the timing of the conditioned responses, we compared the effects of varying a peripheral conditioned stimulus with the effects of corresponding variations of direct stimulation of the mossy fibers. In one set ...
Cormack L K - - 1997
Constraints on binocular matching were investigated by comparing the thresholds for interocular correlation in random element displays for human and model observers, with element density manipulated as a parameter. The models consisted of ideal decision rules operating on the entire stimulus, only on the edges in the stimulus, or only ...
Ghozlan A - - 1997
In Simon, Hinrich, and Craft's (1970) experiments, two factors, Stimulus-Response Compatibility and Position of Hands, are manipulated. The effects of these factors are not additive. Effects of Stimulus-Response Compatibility are usually explained by the similarity between the sets of stimuli and responses. This similarity leads us to suggest that, in ...
Błaszczyk J W - - 1997
The acoustic startle response (ASR) depends on stimulus parameters such as duration, intensity and particularly on the stimulus rise time. The aim of our study was to determine to what extent the ASR parameters are affected by the spectral characteristics of the stimulus. Therefore, in this experiment the amplitude and ...
Machado A - - 1997
Five experiments addressed the issue of how pigeons learn to discriminate the relative frequency of stimuli. During a sampling period, three different stimuli (keylights) were presented serially, in mixed order, and with different frequencies. During a choice period, the stimuli were presented simultaneously, and reinforcement was arranged for choosing the ...
Cacioppo J T - - 1997
All organisms must be capable of differentiating hostile from hospitable stimuli to survive. Typically, this evaluative discrimination is conceptualized as being bipolar (hostile-hospitable). This conceptualization is certainly evident in the area of attitudes, where the ubiquitous bipolar attitude measure, by gauging the net affective predisposition toward a stimulus, treats positive ...
Lötsch J - - 1997
Nociceptive stimuli consisting of short pulses of gaseous CO(2) applied to the nasal mucosa were investigated in 12 healthy volunteers (six males, six females) with respect to trial-to-trial variability. A statistical rather than a psychophysical approach was employed, focusing on test-retest reliability. According to a randomized, volunteer-blind crossover design, two ...
Marino A A - - 1996
The aims of this study were to test the theory that transduction of low-level electromagnetic fields (EMFs) is mediated like other stimuli, and to determine the false-negative rate of the method used to assess the occurrence of transduction (intra-subject comparison of stimulus and non-stimulus states (ICOS)). A light stimulus was ...
McLean L - - 1996
OBJECTIVE: To investigate the main coupling mechanisms involved in stimulus artifact contamination of evoked potential recordings and to suggest techniques that minimize this interference. DESIGN: A before-after trial of a single subject. SETTING: Measurements were obtained at a university biomedical engineering laboratory. PARTICIPANTS: Data were obtained from one volunteer subject. ...
Gati I - - 1996
Several aspects of a feature-matching theory formulated to account for the roles of stimulus novelty and significance in determining orienting responses (ORs) were examined. Stimulus significance and stimulus novelty were independently manipulated, and the electrodermal component of the OR was measured while sequences of compound pictorial or verbal stimuli were ...
Gescheider G A - - 1996
Vibrotactile amplitude difference limens (DLs) were measured by the continuous pedestal and gated pedestal methods. In both cases, the relative DL decreased as a function of the intensity of the stimulus and the results, in most cases, could be described as a near miss to Weber's law. DLs measured by ...
Francis G - - 1996
Psychophysical studies show that increasing the interstimulus interval (ISI) between two stimuli decreases persistence of the first stimulus. While some researchers account for these results with interactions of transient and sustained inhibition, this paper describes an alternative explanation. In a neural-network model of boundary detection called the boundary contour system, ...
Leuthold H - - 1996
Response speed to a signal is faster when advance information about the forthcoming movement is provided before signal onset. Although this precuing effect is well established, the location of this saving in reaction time (RT) in the information-processing system is controversial. Some authors have claimed that the precuing effect resides ...
Wascher E - - 1996
The present study focused on the relationship between movement- and stimulus-related asymmetries of the electroencephalogram (EEG). In seven tasks the same bilateral stimuli containing asymmetric information were presented but response requirements differed. Three functionally distinct asymmetries were found: (1) an asymmetry over the motor cortex prior to unimanual movements, (2) ...
Bocheva N - - 1996
Two different groups of subjects had to adjust two-dimensional stimuli, differing in size, shape and type (dot patterns or irregular contour figures), within a reference circle. The two groups performed under two different instructions. The first instruction stressed matching the centres of the stimulus and the circle, while the second ...
Pause B M - - 1996
The olfactory event-related potential (OERP) has been described as being dependent on exogenous stimulus features, but no effort has been made to examine possible endogenous determinants. We wanted to separate exogenous and endogenous components of the OERP by using an olfactory oddball paradigm. A high concentration of citral was used ...
Kruse W - - 1996
Interactions between stimulus-induced oscillations (35-80 Hz) and stimulus-locked nonoscillatory responses were investigated in the visual cortex areas 17 and 18 of anaesthetized cats. A single square-wave luminance grating was used as a visual stimulus during simultaneous recordings from up to seven electrodes. The stimulus movement consisted of a superposition of ...
Taylor J L JL Prince of Wales Medical Research Institute, Randwick, N.S.W, Australia. - - 1996
In a previous study, the sensory phenomenon of "backward masking" was used to demonstrate that subjects can preprogram a single stereotyped voluntary movement or movement-sequence and that such a movement can be triggered in response to a stimulus that is not perceived (that is, a stimulus of which the subject ...
Goodin D S DS Department of Neurology, University of California, San Francisco 94143, - - 1996
The anticipatory (preparatory) cerebral events in simple reaction-time tasks may depend on the ability of a subject to predict accurately the time of occurrence of the stimulus requiring a particular response. In order to examine this hypothesis, we recorded cerebral and muscle responses in two different conditions, each involving three ...
Estabrooks P A - - 1996
The purpose of the present study was to determine the isolated effects of stimulus control on attendance at a fitness facility. Participants were members of a university fitness club randomly assigned to control (n = 50), placebo (n = 50), and stimulus control (n = 100) conditions. The control condition ...
Thapar A - - 1996
D. J. Burns (1989) demonstrated that free recall of second-list response terms was better in an interference (A-B, A-C) condition than in a control (D-B, A-C) condition. This reversal of the traditional interference effect was referred to as the reverse-interference effect. Results from Experiments 2-4 in this article discounted several ...
Fishler M G - - 1996
The mechanisms by which extracellular electric field stimuli induce the (re)excitation of cardiac cells in various stages of refractoriness are still not well understood. We modeled the interactions between an isolated cardiac cell and imposed extracellular electric fields to determine the mechanisms by which relatively low-strength uniform monophasic and biphasic ...
Wearden J H - - 1996
Two experiments with human subjects, using short-duration tones as stimuli to be judged, investigated the effect of the range of the stimulus set on temporal bisection performance. In Experiment 1, six groups of subjects were tested on a temporal bisection task, where each stimulus had to be classified as "short" ...
Shieh K K - - 1996
An experiment was conducted to investigate the effect of order of report, identification method, redundant color coding, and stimulus location under dual task conditions on multidimensional stimulus-identification performance. Analysis showed that order of report and identification method did affect speed and accuracy of identification. Subjects reacted faster and more accurately ...
Hainfeld C A CA Department of Cognitive and Linguistic Services, Brown University, Providence, RI 02912, - - 1996
1. Male bullfrogs at two different natural calling sites were presented with playbacks of synthetic advertisement calls differing in phase spectra. Sounds were presented in a ABA design to analyze the ability of the animals to perceive changes in repeated series of stimuli. 2. The number of individual croaks in ...
Looft F J - - 1996
The responses of monkey glabrous skin slowly adapting (SAI, Merkel cell), rapidly adapting (RA, Meissner) and Pacinian corpuscle (PC) mechanoreceptors were analyzed as a function of the instantaneous position, velocity, and acceleration of a dynamic stimulus. For these experiments, a vibrotactile punctate stimulator was driven by a non-repeating-noise sequence. The ...
Kato I - - 1996
The optokinetic nystagmus (OKN) test has diagnostic values in that it can detect lesioned sites in patients with infratentorial lesions. The test has so far been performed by using angular acceleration to the final velocity over 100 degrees/s, which is time-consuming and inconvenient for patients. In the present study, we ...
Prete F R - - 1996
Adult, female praying mantises, Sphodromantis lineola (Burmeister), were presented with mechanically driven or computer generated stimuli in a series of seven experiments in order to test several hypotheses regarding visual prey recognition. When presented with a series of square black and white computer generated stimuli against a white background, mantises ...
Looft F J - - 1996
Spectral transfer functions for monkey glabrous skin tactile mechanoreceptors were computed and compared to the results from a dynamic stimulus state analysis for the same receptors. For both sets of experiments, a vibrotactile indenting punctate stimulus driven from a non-repeating-noise (NRN) signal source was used to activate afferents. In all ...
Blood A J - - 1995
Optical imaging of intrinsic signals was performed in the barrel cortex of the rat during whisker deflections of varying frequencies (1 to 20 Hz) and durations (0.1 to 5 s). A dose-response relationship was shown between these stimuli and the characteristics of the optically recorded intrinsic signal response. At constant ...
Kobashi N - - 1995
In this study simple reaction time (simple RT) to a visual stimulus of a single subject was measured during spontaneous and controlled breathing, in which the duration of expiration was prolonged (Asian technique). The phases of breathing were classified as the pause between expiration and inspiration, the inspiration phase, the ...
Case P - - 1995
Previous work (Tuller, Case, Ding, & Kelso, 1994) has revealed signature properties of nonlinear dynamical systems in how people categorize speech sounds. The data were modeled by using a two-well potential function that deformed with stimulus properties and was sensitive to context. Here we evaluate one prediction of the model--namely, ...
Hasbroucq T - - 1995
Reaction time (RT) is shorter when the irrelevant location of the stimulus corresponds to the relevant location of the response: When a subject is to perform a left or right keypress according to the colour of a stimulus delivered either to the left or to the right of a fixation, ...
Tang Y - - 1995
A number of excitable cell types respond to a constant hormonal stimulus with a periodic oscillation in intracellular calcium. The frequency of oscillation is often proportional to the hormonal stimulus, and one says that the stimulus is frequency encoded. Here we develop a theory of frequency encoding in excitable systems ...
Takayanagi S - - 1995
The objective was to provide a more comprehensive understanding of how people make numerical comparative judgments when digits are contained in numbers with redundant leading or following zeros, e.g., 00080 and 800.000. These sequences of numbers often appear on computer display terminals (VDT) as line numbers, but surprisingly little research ...
Hackley S A - - 1995
Fundamental properties of an important new tool in cognitive electrophysiology, the lateralized readiness potential (LRP), were examined in two experiments. Experiment 1 resolved an apparent inconsistency in the literature by demonstrating that this response-specific lateralization is larger preceding complex then preceding simple finger movements. In Experiment 2, the foveally presented ...
Weeks D J - - 1995
It has previously been shown that, when stimuli positioned above or below a central fixation point ("up" and "down" stimuli) are assigned to left and right responses, the stimulus-response mapping up-left/down-right is more compatible than the mapping up-right/down-left for responses executed by the left hand in the left hemispace, but ...
Ito M - - 1995
The purpose of this study was to examine whether the similarity of R1 and R2 is a moderating variable in the psychological refractoriness effect. 10 subjects were required to react and produce the sequence of two homogeneous or heterogeneous peak forces as soon as possible after Stimulus 1 and 2 ...
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