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Results 651 - 700 of 952
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Cooper J - - 1992
We investigated the role of various stimulus parameters that influence motor fusion responses for peripheral as compared to central fusional stimuli. Results from the initial experiment indicated that a central stimulus equal in size to a peripheral fusion stimulus dominated the response independent of the amount of retinal eccentricity of ...
Lewkowicz D J - - 1992
Responses to unimodal and multimodal attributes of a compound auditory/visual stimulus were investigated in 4-, 6-, 8-, and 10-month-old infants. First, infants were habituated to a compound stimulus consisting of a visual stimulus that moved up and down on a video monitor and a sound that occurred each time the ...
Riccio D C - - 1992
Differential responding to changes in the stimulus situation, long central to the concept of stimulus control, also provides the implicit conceptual basis for assessing the nature of a variety of associative relationships. However, there is substantial evidence that the perception of stimulus similarity is not a static property. Generalization gradients ...
Reeve T G - - 1992
A pattern of differential reaction time (RT) benefits obtained in spatial-precuing tasks has been attributed to translation processes that operate on mental codes formed to represent the stimulus and response sets. According to the salient-features coding principle, the codes are based on the salient stimulus and response features, with RTs ...
Hudson C - - 1992
The effects of age, stimulus size, meridian, and eccentricity on physiologic statokinetic dissociation were investigated in clinically normal subjects using the Humphrey field analyzer (HFA, model 640), an automated perimeter capable of both static and kinetic perimetry. The right eyes of 20 age-matched young and 20 age-matched elderly volunteers was ...
Barry R J - - 1992
This study examined the N100 component of the event related potential in a habituation paradigm with short interstimulus intervals. The paradigm was designed to be relatively brief in duration (approx. 4 min for each of two conditions), so that it could be used for clinical populations with cognitive dysfunction, in ...
Tyler C W - - 1992
A new technique is presented for the psychophysical measurement of the response phase that requires no assumptions of the relation between the phase and amplitude components of the frequency response. The amplitude attenuation is measured by a standard threshold paradigm and is then compensated for by increasing harmonic strength in ...
DeGrandpre R J - - 1992
Conditional "if-then" relations between drug (interoceptive) stimuli and visual (exteroceptive) stimuli were taught to 4 normal humans. Interoceptive stimuli were the effects produced by 0.32 mg/70 kg triazolam (a prototypical benzodiazepine) and placebo (lactose-filled capsules); exteroceptive stimuli were black symbols on white flash cards. Following the training of the prerequisite ...
Thomas D R - - 1992
Six experiments were carried out to compare go/no-go and choice paradigms for studying the effects of intradimensional discrimination training on subsequent measures of stimulus generalization in human subjects. Specifically, the purpose was to compare the two paradigms as means of investigating generalization gradient forms and frame of reference effects. In ...
Checkosky C M - - 1992
Based on physiological and psychophysical data, it has been suggested that the neural code for threshold detection in the P channel, mediated by Pacinian corpuscles (PCs), may be 2-4 neural impulses/stimulus (Bolanowski et al., 1988). To further test the efficacy of this code, responses from PCs were measured at different ...
Loftus G R - - 1992
A briefly presented visual stimulus engenders an available-information function that lags behind the physical stimulus. We report two experiments that focus on the iconic-decay portion of this function, which falls to 0 over a 200-300 ms period following stimulus offset. In each experiment, to-be-reported digit strings were shown for varying ...
Ben-Shakhar G - - 1992
The relationship between electrodermal responsivity and stimulus similarity was previously demonstrated in a series of studies. These studies were guided by a feature-matching model according to which similarity is an additive function of the common and distinctive features of the stimuli. In these experiments common and distinctive features were simultaneously ...
Bobier W R - - 1992
Previous measurements of static accommodation have consistently shown steady state errors over most of the range; the response lags below the stimulus and, at low levels, the response leads the stimulus. A series of experiments is presented in which the longitudinal and, for the first time, transverse chromatic aberrations of ...
Saunders R R - - 1992
Sidman and his colleagues derived behavioral tests for stimulus equivalence from the axiom in logic and mathematics that defines a relation of equivalence. The analogy has generated abundant research in which match-to-sample methods have been used almost exclusively to study interesting and complex stimulus control phenomena. It has also stimulated ...
Wang D D Center for Neural Engineering, University of Southern California, Los Angeles - - 1992
Recently, a neural model of visual pattern discrimination for stimulus-specific habituation was developed, based on previous behavioral studies which demonstrated that toads exhibit a dishabituation hierarchy for different worm-like stimuli. The model suggests that visual objects are represented by temporal coding and predicts that the dishabituation hierarchy changes when the ...
Guterman Y - - 1992
To determine if attentional factors influence the suppression of the auditory P50 in a conditioning-testing paradigm, known as the 'sensory gating' effect, we tested 10 healthy young adults in four experimental conditions. The first condition was the traditional passive conditioning-testing paradigm in which a pair of identical auditory clicks is ...
Gottsdanker R - - 1992
The method of brief PSIs (precue-to-stimulus intervals) was used in three RT (reaction-time) experiments to explore the generality of the precue-utilization effect in rapid reactions, and to examine two extensions. This effect, which shows the self-contained performance in the choice reaction of the processing operations that culminate in response selection, ...
Korth M - - 1992
The typical pattern-onset-offset stimulus (stimulus A) consisting of local luminance increases and decreases was broken down into stimuli presenting only local luminance increases (stimulus B) or only local luminance decreases (stimulus C). With stimulus B the onset ERGs are luminance responses. With stimulus C the onset ERGs are pattern-related responses ...
Pennebaker G E - - 1992
We studied the effect of varying the stimulus duration time on the components of fluctuation in static automated perimetry by testing 20 healthy subjects on the Humphrey Field Analyser within the central 20 degrees of vision. We found the total fluctuation at a stimulus duration of 0.065 s, to be ...
Silva F J - - 1992
Three pigeons were exposed sequentially across experimental phases to five different distances between the conditioned stimulus and the site of the unconditioned stimulus in a sign-/goal-tracking procedure. A computer-controlled tracking system provided a continuous record of the bird's position by continuously monitoring the location of the bird's head in three-dimensional ...
Baltissen R - - 1991
Effects of arginine-vasopressin (AVP) on the habituation of the orienting reaction and response to stimulus mismatch were investigated in a between-group design with 40 healthy male volunteers using skin conductance and heart rate responses as dependent measures. Twenty-one 1000 Hz tones of 90 dB(A) intensity and 2 s duration were ...
Pietrantoni M - - 1991
The effect of stimulus duration on the initial fetal heart rate (FHR) acceleration response was evaluated by assessing its amplitude and span following a single vibroacoustic stimulation with durations of 0 (sham), 1, 3, or 5 seconds. Statistically significant differences were observed in the mean amplitude and duration of acceleration ...
Eaton R C - - 1991
Fishes use the Mauthner-initiated C-start for short-latency evasion of predators. C-starts consist of a sudden turn (stage 1) and a rapid acceleration (stage 2). We analyzed high-speed ciné films of goldfish C-starts elicited by dropping a ball into the water. It was previously thought that stage 1 angle does not ...
Wulfert E - - 1991
In two equivalence experiments, a "think aloud" procedure modeled after Ericsson and Simon's (1980) protocol analysis was implemented to examine subjects' covert verbal responses during matching to sample. The purpose was to identify variables that might explain individual differences in equivalence class formation. The results from Experiment 1 suggested that ...
Pinheiro A D AD Division of Biological Sciences, University of Missouri, Columbia - - 1991
1. Encoding of temporal stimulus parameters by inferior collicular (IC) neurons of Eptesicus fuscus was studied by recording their responses to a wide range of repetition rates (RRs) and durations at several stimulus intensities under free field stimulus conditions. 2. The response properties of 424 IC neurons recorded were similar ...
Dougherty D M - - 1991
Using horses, we investigated three aspects of the stimulus control of lever-pressing behavior: stimulus generalization, discrimination learning, and peak shift. Nine solid black circles, ranging in size from 0.5 in. to 4.5 in. (1.3 cm to 11.4 cm) served as stimuli. Each horse was shaped, using successive approximations, to press ...
Casey B J - - 1991
A refractory period for the heart rate (HR) response of 14-, 20-, and 26-week-old infants to second stimulus onset and primary stimulus offset during termination of visual attention was investigated. A stimulus that elicited a significant HR deceleration was presented. Following the return of HR to prestimulus level, a second ...
Alling K - - 1991
Pigeons were exposed to delayed-matching-to-sample procedures in which food or a flash of the feeder light followed correct responses. When these consequences were correlated with a particular stimulus (e.g., food followed matching responses to red and a flash of the feeder light followed matching responses to green), accuracy was significantly ...
Hermes D J - - 1991
In intonation research, prominence-lending pitch movements have either been described on a linear or on a logarithmic frequency scale. An experiment has been carried out to check whether pitch movements in speech intonation are perceived on one of these two scales or on a psychoacoustic scale representing the frequency selectivity ...
Christman S - - 1991
Observers indicated whether a stimulus presented to one visual field or the other consisted of two sine-wave gratings (the baseline stimulus) or those same two gratings with the addition of a 2 cycle per degree (cpd) component. When the absolute spatial frequencies of the baseline stimulus were low (0.5 and ...
Parker B K - - 1991
Two experiments were conducted using an autoshaping procedure with pigeons to examine whether dimensional stimulus control by a Pavlovian facilitator parallels the control established following operant discrimination training. Facilitation training consisted of the presentation of a black vertical line on a white background as the B stimulus in a feature-positive ...
Boelhouwer A J - - 1991
In a warned Go/No-Go reaction time experiment blink reflexes were elicited electrically immediately before, at, and shortly after the onset of a low intensity acoustic warning stimulus. This provided the opportunity to study the mutual effects of two stimuli of different modalities arriving at the facial nucleus. The warning stimulus ...
Dixon P - - 1991
Partial report performance is conceived of as consisting of two independent sources of information: visible persistence and schematic persistence. Following the work of Di Lollo and Dixon (1988), these two sources of information were separated experimentally by varying interstimulus interval and stimulus onset asynchrony independently. In the present experiment we ...
Clark C D - - 1991
In previous studies, it has been demonstrated that visible persistence--the period for which the perceived duration of a stimulus exceeds its physical duration--can be extended by briefly incrementing the luminance of the stimulus immediately prior to offset. Using a two-component pattern integration task, we show that this effect is not ...
Dembowski J - - 1991
Nonstutterers', mild stutterers', and severe stutterers' acoustic laryngeal reaction times (LRTs) were recorded for isolated vowels and nonpropositional VCV responses in different stimulus conditions governing response preparation. In all stimulus-response conditions severe stutterers produced the longest LRTs, followed in turn by mild stutterers and nonstutterers. The three groups significantly differed ...
Post L J - - 1991
Although it is well known that attention to a visual or auditory stimulus can enhance its perception, less is known concerning the effects of attention on the perception of natural tactile stimuli. The present study was conducted to examine the magnitude of the effect of cross-modal manipulations of attention in ...
Eisenstein E M - - 1991
Habituation and sensitization of the galvanic skin response (GSR) to shock were studied in college males. One would expect that at any given time individuals vary on a continuum in the degree of their initial GSR responsiveness to a stimulus. Here it is shown that those on the higher end ...
Jaƛkowski P - - 1991
Temporal-order judgment was investigated for a pair of visual stimuli with different durations in order to check whether offset asynchrony can disturb the perception of the order/simultaneity of onset. In experiment 1 the point of subjective simultaneity was estimated by the method of adjustment. The difference in duration of the ...
Teyke T - - 1990
The appetitive phase of feeding behavior in Aplysia consists of a behavioral sequence in which the quiescent animal starts to locomote and then assumes a characteristic feeding posture. In this position, head-turning responses can be elicited by a localized food stimulus (seaweed) delivered to the lips or tentacles. In response ...
Lachnit H - - 1990
Eastern and Western interpretations of contextual control of phasic conditional responses (transswitching) are contrasted. The Eastern (Asratyan, 1965) approach emphasizes the role of the tonic conditional stimulus and the (hypothetical) tonic response it evokes. The Western (Lachnit, 1986) approach emphasizes the role of compound conditional stimuli. Although Lachnit showed that ...
Chapman G B - - 1990
Most studies of human contingency judgment have been based on the assumption that frequency information about one predictor is assessed in isolation of information about other predictors. Recent evidence, however, suggests that the judged predictive strength of one cue is influenced by the predictive strengths of other copresent cues. Two ...
Fisher S K - - 1990
Changes in tonic accommodation and tonic vergence were studied as a function of stimulus duration and time after near fixation. Thirteen visually normal young adults each participated in experimental sessions comprising each of 12 combinations of stimulus type (accommodative or vergence) and stimulus duration (0.25, 0.5, 1, 2, 4, or ...
Polich J - - 1990
Hemispheric differences for local and global processing were assessed with square and rectangular stimulus shapes which contained either squares or rectangles within them. Experiment 1 manipulated the overall size and area of the stimulus items, while experiment 2 kept stimulus area constant and manipulated the number of shapes inside the ...
Ison J R - - 1990
The cutaneous eyeblink has 2 electromyographic components, 1 unilateral and early (R1) and 1 bilateral and late (R2), which are served by different neural pathways. These 2 reactions were measured when the eliciting stimulus was expected or relatively surprising. Forewarning was varied in 3 ways: Subjects received notice that the ...
Green D M - - 1990
In adaptive psychophysical procedures, the stimulus should be presented at a relatively high level rather than near the middle of the psychometric function, which is often defined as the "threshold" value. For some psychometric functions, the optimal stimulus placement level produces 84% to 94% correct responses in a two-alternative forced-choice ...
Lamb M R - - 1990
It has been shown that there is a transition from a global to a local advantage in reaction time as visual angle increases (Kinchla & Wolfe, 1979), and it has been assumed that this transition reflects lower level (e.g., retinal) processes. In three experiments, we examined whether higher level (e.g., ...
Dornier L A - - 1990
The present study evaluated the role of compatibility effects in the precuing of arm and direction parameters. In the first two experiments different stimulus and response arrangements were examined. For all three experiments the spatial precue and imperative stimuli were compatibly assigned to responses (i.e., a direct correspondence existed between ...
Choplin N T - - 1990
Patients with severely depressed visual fields as determined by automated static perimetry are often tested with larger test stimuli in order to obtain meaningful data. "Normal" threshold values are known and included in some perimeters' data analysis programs for stimulus III, but not for larger stimuli. Using a user-defined program ...
Mori S - - 1990
The fuzzy judgement model of Ward (1979) predicts an inverse relation between the amount of stimulus information available to subjects and the magnitude of sequential dependencies on previous stimuli and responses in psychophysical scaling tasks. Ward confirmed this prediction for magnitude estimations of interdot distance for previous responses but not ...
Saihara S - - 1990
A noncapturing conditioning stimulus is known to exert inhibitory effect on a subsequent suprathreshold stimulus, while summation occurs rarely in man. The present study was conducted to revaluate whether conditioning stimulus at a relatively low intensity produced inhibition and summation in man. Thirteen patients with various arrhythmias, 47 +/- 19 ...
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