Search Results
Results 601 - 650 of 952
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Diamond D - - 1995
This study investigated the effect of levels of prior fear to a fear-relevant stimulus on UCS expectancy ratings in a threat conditioning procedure. The results suggested that UCS-expectancy ratings are independently influenced by both the nature of the stimulus (whether it is fear-relevant or fear-irrelevant) and the level of prior ...
Ferger B. - - 1995
In previous studies, it was shown that apomorphine-induced stereotyped behaviour could be conditioned when apomorphine was repeatedly paired with sensory stimuli (CS). Since in these experiments, the sum of various sensory stimuli were applied, it seemed of interest to use each sensory stimulus separately in order to evaluate the relevance ...
Manahilov V - - 1995
The spatiotemporal visual response to an inducing bar of a short duration was studied by a brightness-matching procedure. The apparent brightness of a test line, presented in the centre of an inducing bar, exhibited a U-shaped dependence of the inducing-bar width with a minimum at about 4.5' width. The temporal ...
Schifferstein H N - - 1995
Manipulating stimulus spacing, stimulus frequency, or stimulus range usually affects intensity judgments. In six experiments, I investigated the locus of analogues of these contextual effects in a "difference" estimation task. When all stimuli elicited the same taste quality, stimulus distribution affected the scale values only when water was included in ...
Rose D - - 1995
The first stimulus in a sequential train of identical flashes of light appears to last longer than those in the middle of the train. Four flashes (each 600 or 667 ms) were presented and the first was shortened until it appeared to have the same duration as that of the ...
Falk J L - - 1995
Rats were exposed daily to a food schedule-induced polydipsia condition, in which water and 0.16 mg/ml cocaine solution were available concurrently, with the cocaine solution indicated by a discriminative stimulus (SD) light. The cocaine solution was preferred, and the preference was maintained when the SD was gradually eliminated by fading ...
Jacobs W J - - 1995
We present a model of Pavlovian excitatory conditioning in which associative strength and malleable central representations of unconditional stimuli determine the strength of conditional responding. Presentation of a conditioned stimulus acts through an experientially determined associative bond to activate a representation of the unconditional stimulus. The activation of the representation ...
Ben-Shakhar G - - 1995
This study focused on the effects of common and distinctive stimulus components on the generalization of the orienting response (OR) to significant stimuli. Compound pictorial stimuli were used as the relevant items memorized by the subjects. Skin conductance responses were measured during the subsequent presentation of a stimulus sequence that ...
Etnyre B R - - 1994
The effects on timing of anticipation following an isometric contraction were investigated. Using a Bassin timer, 35 subjects performed 10 trials for each of 4 forewarning periods at 3 stimulus speeds resulting in 120 trials for the control condition. An additional 120 trials were performed by all subjects following an ...
Hammer M - - 1994
Stimulus-induced arousal (sensitization) of a component of appetitive behavior in honeybees, the proboscis extension reflex (PER), was used to investigate different aspects of nonassociative memory. The sensitizing stimulus (sucrose solution) was applied to one antenna, as a compound to antenna and proboscis, and to the proboscis. Stimulus duration was either ...
Tsal Y - - 1994
The effects of attention on brightness perception was investigated in four experiments. In the first three, subjects estimated the brightness of a briefly presented small grey square by selecting a number that corresponded to one of four possible squares varying on a lightness-darkness dimension. In the last experiment, subjects matched ...
Stein C - - 1994
1. The great majority of data supporting the hypothesis of a system capable of comparing current sensorial inputs with an internal representation of the environment comes from studies about exploratory activity to new stimuli or to manipulation of features of a familiar stimulus. On the other hand, these data could ...
Cohen N - - 1994
In the classical Pavlovian conditioning paradigm, a stimulus that unconditionally elicits a physiological response is repeatedly paired with a neutral stimulus that does not elicit that same response. Eventually, the neutral stimulus becomes a conditioned stimulus in that it elicits the physiological response in the absence of an unconditioned stimulus. ...
Zahn T P - - 1994
Two reaction time (RT) paradigms were used to study clozapine's effects on sustained and selective attention compared to fluphenazine and placebo in 25 chronic schizophrenic patients. Sensory dominance was studied via simple and choice RTs to lights and tones, and on double-stimulus trials in which the two stimuli were presented ...
Karunanithi S - - 1994
A study was undertaken to ascertain why in the mouse vas deferens excitatory junction potentials facilitate whereas contractions depress during low frequency stimulation. In a set of contraction studies, where a conditioning stimulus was followed 2 s later by a test stimulus, depression in the first phase of contraction was ...
Schifferstein H N - - 1994
Two experiments investigated whether stimulus context affects ratings for mixtures of dissimilartasting substances (fructose/citric acid) to the same degree that it affects ratings for unmixed substances (fructose). In Experiment 1, replacing mixtures by equisweet unmixed fructose solutions produced virtually no response shifts. The proportion of mixtures in the stimulus set ...
Fera P - - 1994
H. Pashler (1984) reported that when subjects identified a probed letter in a display of 8 characters, the effect of stimulus quality on reaction time persisted full blown even when subjects had 300 ms to preprocess the display. Pashler argued that these results are incompatible with theories of late selection ...
Schifferstein H N - - 1994
Stimulus distribution, stimulus spacing and stimulus range affect mean intensity ratings of solutions of unmixed tastants. The present study compares contextual effects for mixture ratings with those for unmixed stimuli: if ratings for mixed and unmixed stimuli are differentially affected by context, the degree of mixture suppression inferred from the ...
Richardson R - - 1994
The cardiac orienting response to brief auditory stimuli was measured in preweanling and adult rats. The eliciting stimulus varied in duration (2 or 10 s) and complexity (continuous or pulsing). Stimulus complexity affected response magnitude with the pulsing stimulus eliciting a larger response than the continuous stimulus. Stimulus duration affected ...
Boles D B - - 1994
Three experiments compare the effects of stimulus type, display type, and input variable contributions to visual field (VF) asymmetry. Stimulus types were words and bar graphs; displays were unilateral and bilateral; and input variables were stimulus eccentricity, duration, luminance, and size. The only influences consistent across studies and with claims ...
Los S A - - 1994
In three experiments, the extent to which the processing of a visual stimulus profits from equal processing demands of a preceding stimulus was examined. Subjects identified two subsequently presented digits (S1 and S2) that were either intact or degraded by noise, yielding four combinations of stimulus quality. In Experiments 1 ...
Heister G - - 1994
Subjects had to perform both in a classical spatial compatibility experiment where they were instructed to press a right or left button to a right or left stimulus ('positional instruction'), and in a variant, where they had to give a spatially compatible or incompatible response depending on the color of ...
Hommel B - - 1994
Choice-reaction time is known to depend on the spatial correspondence of stimulus and response, even if the stimulus location is irrelevant to the task (Simon effect). An experiment investigated whether this effect depends on stimulus complexity--i.e., on whether properties of the stimulus render stimulus discrimination easy or difficult. It was ...
Proctor R W - - 1994
Within the visual-spatial and auditory-verbal modalities, reaction times to a stimulus have been shown to be faster if salient features of the stimulus and response sets correspond than if they do not. Accounts that attribute such stimulus-response compatibility effects to general translation processes predict that similar effects should occur for ...
Claussen C F - - 1994
Regulation of the human equilibrium differs from the other, mostly linear, human senses. It consists of a multitude of receptors and an interrelated network that is necessary for data processing as well as for regulatory processes. Thus, the human equilibrium system represents a mixture of hardware and related software interactions. ...
Nakajima I - - 1994
We examined the relationship between contingent negative variation (CNV) amplitude and digastric muscle activity in jaw-opening motor task. Subjects were instructed to open their jaws in response to a sound stimulus following a visual warning stimulus. Electroencephalograms were averaged by using the visual stimulus pulse as a trigger. Bilateral CNVs ...
Johnson M C - - 1994
Three experiments were conducted to examine the effectiveness of different forms of tactile stimulation, probe and stream, and interstimulus intervals (ISI) in producing habituation in the polypoid sessile stage of the jellyfish Aurelia aurita. Results from Experiment 1 showed that polyps significantly decreased their responsiveness to both forms of tactile ...
Hommel B - - 1994
Two experiments investigated whether the Simon effect (i.e., faster responses to spatially corresponding than to noncorresponding stimuli, with stimulus location being irrelevant) is affected by the frequency of noncorrespondence trials. Stimulus discriminability (Experiment 1) and immediate or delayed stimulus formation (Experiment 2) was varied in order to manipulate the temporal ...
Nakamizo S - - 1994
Visual directions of the two stimuli in Panum's limiting case with different interstimulus and convergence distances confirmed the predictions from the reformulated Wells-Hering's laws of visual direction. In experiment 1, six observers each converged on the midpoint of the interstimulus axis at 30, 60, and 90 cm from the eyes ...
Rescorla R A - - 1994
Two experiments used rats to examine the transfer of control of a stimulus to a new instrumental response. That transfer was successful to the degree that the stimulus and the response shared a common outcome. The transfer was more substantial, however, when the stimulus signaled the availability of that outcome ...
Cox R H - - 1993
24 boys and 16 girls ages 4 through 7 years were tested on an apparatus that required children to select the middle of 3, 5, 7, or 9 stimulus lights when arranged adjacent to one another and when spaced symmetrically or asymmetrically. Analysis indicated response time decreased with age and ...
Smeets P M - - 1993
Previous research (Smeets, 1991) suggested that when given a new discrimination, children respond on the basis of physical similarity with previously discriminated stimuli. They respond to a stimulus similar to another preferred stimulus (S+ transfer) and respond away from a stimulus similar to another nonpreferred stimulus (S- transfer). When both ...
Kowal K H - - 1993
The intramodal range effect (an inverse relationship between stimulus range and exponent in Stevens's power law) has been well documented, but its conditions have not been tested. Both the estimates of stimulus magnitudes and their exponents are affected by context, stimulus location, and different standards and moduli, but how these ...
Stillman J A - - 1993
The effect of stimulus range and stimulus spacing was examined when subjects registered the perceived intensity of sweet liquids using either a matching procedure (Experiment 1) or category rating (Experiment 2). The matching procedure is conceptually similar to absolute magnitude estimation, whereby subjects match their impression of number size to ...
Goodin D S - - 1993
We investigated the relationship between sensory discrimination and the selection of appropriate responses in subjects performing two different reaction-time tasks, in which three auditory stimuli were presented in random order and with a different likelihood of occurrence. Subjects anticipated the need to make different responses based on the likelihood that ...
Romaiguère P - - 1993
In reaction time studies of stimulus-response compatibility, emphasis has been placed on the influence of spatial stimulus-response relationships, but what seems to be essential for the emergence of an effect of stimulus-response compatibility is the existence of a conceptual match between stimulus and response variables. This notion was at the ...
Spitzer H - - 1993
When an inhibitory visual stimulus is turned off, an increased rate of spike discharge is evoked which we term the "rebound response". This response exists as a part of different cell responses from the retina to the cortex. The rebound response, with its temporal dependence on stimulus parameters, has not ...
Frank R A - - 1993
Observers are often asked to make intensity judgments for a sensory attribute of a stimulus that is embedded in a background of "irrelevant" stimulus dimensions. Under some circumstances, these background dimensions of the stimulus can influence intensity judgments for the target attribute. For example, judgments of sweetness can be influenced ...
Carstens E - - 1993
1. The aim of this study was to develop a quantitative behavioral model of nociception. Electromyographic (EMG) recordings from a hamstring flexor muscle provided a measure of the magnitude of hindlimb withdrawals elicited by brief, graded noxious contact thermal stimuli applied to the hindpaw in conscious rats. 2. The magnitude ...
Rosenfield M - - 1993
In the absence of an adequate visual stimulus, accommodation adopts an intermediate position of approximately 1 D. Since this position was believed to reflect the level of tonic innervation to the ciliary muscle, this response has been termed tonic accommodation (TA). Part I of this review will consider various aspects ...
Bossink C J - - 1993
Levelt's second proposition (1968) was tested by investigating the effect of increasing the stimulus strength on the ipsilateral mean dominance duration. In three experiments, three stimulus dimensions were investigated: luminance contrast, colour contrast, and motion velocity. We included an experiment similar to Levelt's own equipment, in which a reversed contrast ...
Reyes del Paso G A - - 1993
An investigation to examine the relationships between breathing activity and the cardiac defense response (CDR) to intense auditory stimulation is reported. 42 subjects (20 men and 22 women) underwent a physiological reaction test consisting of three trials of a distorted 400 Hz noise of 100 dB, 0.5-s duration and instantaneous ...
Proctor R W - - 1993
A two-choice reaction task was used to evaluate changes in stimulus-response translation with practice. In Experiment 1, four groups of Ss practiced with either a direct or indirect mapping of left-right stimuli to left-right responses and either a crossed or uncrossed hand placement and transferred to one of the four ...
Szalai J P - - 1993
The study elucidated the role of deployment of attention in the appearance and magnitude of the overlearning reversal effect (ORE) with simultaneously occurring aggressive and neutral stimulus dimensions in a discrimination reversal-shift paradigm with 60 undergraduate college students. Confirming expectations, significantly larger overlearning reversal effect (ORE) was produced on the ...
Dougherty D M - - 1993
Using horses, we investigated the control of operant behavior by a tactile stimulus (the training stimulus) and the generalization of behavior to six other similar test stimuli. In a stall, the experimenters mounted a response panel in the doorway. Located on this panel were a response lever and a grain ...
Harvey J A - - 1993
In this study we examined the effects of harmaline on Pavlovian conditioning of the rabbit's nictitating membrane response. The acquisition of conditioned responses was determined during a single session consisting of 120 pairings of a tone-conditioned stimulus with a corneal air puff unconditioned stimulus. Harmaline severely retarded (5 mg/kg) or ...
Proctor R W - - 1993
Michaels reported a compatibility effect in which responses were fastest at the destination of a moving stimulus; she interpreted this "destination" compatibility effect in terms of catching actions "afforded" by the stimulus motion. The present study evaluated implications of the catching-affordance account and compared them with those of an account ...
Hommel B - - 1993
It has been claimed that spatial attention plays a decisive role in the effect of irrelevant spatial stimulus-response correspondence (i.e., the Simon effect), especially the way the attentional focus is moved onto the stimulus (lateral shifting rather than zooming). This attentional-movement hypothesis is contrasted with a referential-coding hypothesis, according to ...
Farah Andy - - 1993
There is debate in the psychiatric community regarding how to optimize electroconvulsive therapy (ECT). American Psychiatric Association recommendations suggest a moderately suprathreshhold stimulus intensity, yet little information is available regarding how practitioners select initial ECT stimulus doses. We report the results of a nationwide study of common ECT practices. Respondents ...
Sergio L E LE Department of Psychology, McGill University, Montreal, Quebec, - - 1993
The three-dimensional kinematics of the hindlimb back-wipe were examined in spinal frogs. The component movements were identified and the relationship between stimulus position and hindlimb configuration was assessed. The planes of motion of the hindlimb were examined throughout the movement. The back-wipe comprises three essential phases: a placing phase (I), ...
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