Effects Of Stimulus Repetition Research Articles

Effect of stimulus repetition on positive and negative identity priming.

Most negative-priming experiments have used a limited number of stimuli that are repeated many times throughout the experiment. We report five experiments that examine in greater detail the role of stimulus repetition in negative priming. Subjects were presented with displays consisting of two or more words, and were required to name the word printed in red. On attended repetition (AR) trials, the target word was the same as the target word on the preceding trial. On ignored repetition (IR) trials, the target word was the same as the distractor word on the preceding trial. Experiments 1 and 2 used novel words, and obtained positive priming on AR trials, but no negative priming on IR trials. Experiments 3 and 4 used repeated words, and obtained negative priming on IR trials, but no positive priming on AR trials. In Experiment 5, both novel and repeated words were intermixed, and negative priming was observed for repeated, but not novel, IR conditions, whereas positive priming was observed for novel, but not repeated, AR conditions. Together, Experiments 1-5 demonstrate that positive and negative identity priming are modulated by stimulus repetition and are stimulus specific.

The shape of the vibrotactile loudness function: the effect of stimulus repetition and skin-contactor coupling.

In the psychophysical literature describing the relationships between physical and psychological magnitudes, as physical intensity increases, perceived intensity often grows much faster near threshold than at higher levels. In this laboratory, however, the loudness curve for sinusoidal vibrotactile stimuli was best fit by a single-limbed function rather than by the expected two-limbed function. In the present study, we measured the growth of vibrotactile loudness of 250-Hz sinusoidal stimuli by the method of absolute magnitude estimation to explore the source of the one- versus two-limbed discrepancy. The number of times that the stimulus was presented was varied, as well as whether the stimulator contacted the skin with constant force or constant penetration. Neither of these manipulations affected the shape of the loudness function consistently. Number of repetitions influenced the shapes of the magnitude estimation functions, but only for a few individuals. Skin-contactor coupling did not affect the shapes of the functions, although the absolute level (vibrotactile loudness) was consistently greater for constant indentation.

Effects of stimulus alternation, repetition and response requirements on event-related potentials to patterned visual stimuli

Event-related potentials (ERPs) were recorded to square-pattern stimuli presented either to the upper or the lower half of the visual field. In the Same task the subjects had to respond to the fifth stimulus of a microsequence of stimuli that appeared on the same half field, whereas in the Different task the target stimulus was the alternation of stimulus location after a microsequence of four stimuli to the same half field. The pattern-specific CII component (a negative wave to lower half-field stimulation with 100 ms latency) appeared to be insensitive to task variables. N1 increased to the uncertain alternations of stimulus location. An N2 component with temporal maximum emerged to Nogo stimuli (to the fifth stimulus in the same location in the Different task and the alternation after four identical stimuli in the Same task). An anterior N2 was characteristic to the Nogo stimuli of the Different task. P3 latency was longer, and it had more anterior distribution to the Nogo stimuli.

The effects of immediate stimulus repetition on reaction time and event-related potentials in tasks of different complexity.

The effects of immediate stimulus repetition on reaction time and event-related potentials in tasks of different complexity.

The effects of immediate stimulus repetition on reaction time and event-related potentials in tasks of different complexity.

The effect of immediate stimulus repetition was examined in lexical decision, face recognition, letter search, face/nonface discrimination, and word/number discrimination tasks using reaction time (RT), accuracy, and event-related brain potential (ERP) measures. Repetition facilitated performance in all tasks and for all stimulus types. However, ERPs were strongly affected by repetition only in lexical decision, face recognition, and letter search, when relatively long stimulus analysis and decision making processes were required. The ERP repetition effect consisted of a significant increase in P300 amplitude and a shortening of its latency. Repetition also resulted in the attenuation of a negative component that was tentatively identified as N400

Fast decrement with stimulus repetition in ERPs generated by neuronal systems involving somatosensory SI and SII cortices: Electric and magnetic evoked response recordings in humans

The effect of stimulus repetition (short trains of stimuli with 1-s inter-stimulus intervals and 15-s inter-train intervals) on both electric and magnetic evoked responses were studied in four subjects. In addition to the later N140 and P300 deflections in electric potentials, a distinct and immediate amplitude decrement was obtained also for the earlier P50 and P100 deflections. The magnetic evoked responses also demonstrated the amplitude decrement for 50 ms (M50) and 100 ms (M100) latency deflections. The time-course and degree of amplitude decrement of the M100 magnetic response corresponded especially well to those of P100 electric deflections. The results thus show the rate effect on electric and magnetic responses at 50 and 100 ms latencies, and further suggest that the electric and magnetic responses, reflecting the activation of somatosensory SI and SII cortical areas at these latecies, respectively, are generated by related neuronal mechanisms.

Strength and duration of word-completion priming as a function of word repetition and spacing

We assessed the effects of stimulus repetition and spacing on the strength and duration of word-completion priming. Subjects studied words presented 4, 16, or 32 times and were then given tests of word-stem completion and recognition memory. The words were presented in one session with an immediate, 2-h, or 24-h test; or in four sessions spaced 2 h apart with a test 24 h after the final session. Other subjects were presented the same set of words 1, 2, or 4 times and were tested immediately after word-list presentation. The subjects tested in the immediate conditions exhibited priming, but the subjects in the delay or spaced conditions did not. The subjects exhibited stronger priming effects after four repetitions of the list words than after only one or two repetitions; however, priming effects were not further increased by 16 or 32 repetitions. In contrast, recognition memory performance declined only slightly across 24 h and improved as the number of repetitions increased from 1 to 32. Word-completion priming following presentation of single words appears to be short-lived and may reach a maximum after a few presentations.

Effects of Stimulus Repetition, Duration, and Rise Time on Startle Blink and Automatically Elicited P300

Intense auditory stimuli of sudden onset evoke not only startle blinks but also an event-related potential component resembling classic P300, even when subjects have no assigned task. To more closely examine the relationship of this P300 to startle, event-related potentials and eyeblink were recorded from 16 young adults in three paradigms designed to produce wide variation in startle amplitude: an Habituation series of 30-ms, 105dBA white noise bursts, a Duration paradigm which presented 105dB noise bursts for 3, 10, 30, or 90 ms, and a Rise Time paradigm which varied the rise/fall times (3, 15, 30, and 45 ms) of 110dBA, 1000-Hz tone bursts. Subjects received two runs of each paradigm. Only on the final Duration and Rise Time runs were stimuli explicitly task relevant; on those runs subjects rated verbally, midway in each 8.4-s interstimulus interval, the disturbingness of the prior sound. Although even the briefest noise bursts evoked parietal P300 as well as startle blink, P300 did not behave like startle. P300 habituated more slowly than did blink amplitude, was more responsive to sustained noise than were blink, N110, and P190, and most importantly, did not show the sensitivity to stimulus rise time manifested by these measures. These findings suggest that the amplitude of automatically elicited P300 is not governed by the same mechanisms as startle amplitude, but behaves more like a defense response.

The Effects of Prolonged Stimulus Repetition with Repeated Switching of Target Status on the Orienting Response in Schizophrenia and Depression

Schizophrenic patients are frequently orienting nonresponders to innocuous stimuli, become responsive to significant target signals, and become hyporesponsive again on prolonged repetition. We wish to a) determine whether schizophrenic patients can display orienting response (OR) flexibility, responding to newly designated targets and ceasing to respond to newly designated nontargets; b) determine whether renewed hyporesponding can be averted with reminders of target relevance and repeated introduction of new targets; and c) compare schizophrenics with depressives and normal controls. Fifty schizophrenics (14 drug free), 50 depressives (20 drug free), and 50 normal controls receive four trial blocks involving the same sequence of 16 1000- or 2000-Hz tones delivered to either the right or left ear. A subsample of each group (N = 14) receives all blocks as a simple habituation series; others (N = 36) have to press a pedal for designated target signals (left ear or right ear, 1000 Hz or 2000 Hz), ignoring all nontarget tones. On each trial block, a new target signal is defined, and previous targets are discarded. Skin conductance and finger pulse amplitude analyses are presented. Both patient groups show enhanced ORs to newly relevant targets and ceased ORs to newly irrelevant former targets as well as normals. Both show OR decline with target repetition despite reminders and new targets.

Stimulus repetition effects and the dimension-feature distinction in alternative targets.

The negative repetition effect (NRE) refers to a poorer perception of the target in noise-same-as-target than in noise-alternative-target displays. Using the parenthesis as target and noise that are either identical or different in orientation, we tested predictions derived from a feature-specific inhibition model (Bjork & Murray, 1977) that explains the NRE as arising from inhibitory interactions among channels handling identical inputs. Contrary to our expectation of evidence for orientation-specific inhibition, a positive repetition effect (PRE) was observed. We also found a PRE for the dimension target sets whose stimuli differ only in orientation and an NRE for the feature target sets whose stimuli differ in the number of elements. Further experiments that systematically varied relationships between alternative targets indicate that these basic findings, termed the stimulus attributes effects, do not arise from pattern masking, perceptual strategies, or response bias.

Stimulus repetition effects and the dimension-feature distinction in alternative targets.

Stimulus repetition effects and the dimension-feature distinction in alternative targets.

The Acoustic Startle Response and Disruption of Aiming: I. Effect of Stimulus Repetition, Intensity, and Intensity Changes

Three experiments examined the disruption of perceptual motor performance by intense noise bursts. Subjects aimed a rifle at a fixed target for 15-s periods separated by 15 s of rest. This cycle was repeated 30 times in each of two series separated by a 15-min rest, each series containing five noise bursts. The noise bursts disrupted aiming for 1-2 s, an effect that increased with sound pressure level for 110, 120, and 130 dB stimuli. There was no difference between stimuli with energy centered on 250 Hz as opposed to 800 Hz. The effect diminished over the five bursts within the first series (but not to zero) and did not recover in the 15-min rest period. Some subjects received three days of testing; in these cases the effect of the noise bursts partially recovered after rest intervals of 24 hrs and then seven days. Other subjects received 15 trials with 110-dB stimuli, then five more trials with 130-dB stimuli. The disruption of aiming by 130 dB stimuli was not reduced by prior exposure to 110-dB stimuli.

Developmental Studies of Alertness and Encoding Effects of Stimulus Repetition

The findings reviewed here suggest a broadened view of the stimulus-familiarization effect as one of a general class of phenomena resulting from repetition-induced changes in the processes of alterness and encoding. Cantor's original observation of slowed responding to familiarized stimuli can be attributed on this account to experimental conditions under which the magnitude of alterness decrement is greater than encoding facilitation. Exactly the opposite result can be obtained by arranging conditions so as to highlight the encoding facilitation effect relative to the alterness decrement effect. For example, faster responding to familiarized stimuli has been found under conditions in which (1) the imperative stimulus is preceded by a neutral warning signal or, (2) a delay is imposed between the familiarization and the test phases. Earlier, it was noted that the experimental technique of repeated stimulus presentation is widely used in the study of infant perception, with little concern for the mechanisms responsible for what is generically referred to as habituation. Posner and Rothbart (1980) made a similar observation and suggested, on the basis of Kraut's (1976) results, that Habituation in the infant can be viewed as a reduction in the flow of information from the recognition pathway [encoding] into the alerting system. Input is still processed along the recognition pathway, but its failure to activate the alerting system reduces the availability of the central processor and hence of nonhabitual responses. We have developed a model of attention that accounts for our findings and embodies Posner and Rothbart's general idea. It suggests that both the alertness and the encoding functions must reach separate threshold levels for a correct recognition response. The time required to get to each threshold level is changed as a function of stimulus repetition. Repetition slows alertness "rise time," but it speeds encoding "rise time." In comparing the responses to a familiarized color versus those to a novel color, the model can be seen in Fig. 1a. Because any response must await an appropriate level of alertness, the familiarized stimulus is responded to more slowly than the novel one, even though encoding rise time to the familiarized stimulus if fast. Either a delay between familiarization and test or a warning signal acts to mitigate the effects of familiarization on alertness. Alertness rise time for the familiarized stimulus is similar to that for the novel stimulus, but encoding rise time for the familiarized stimulus is faster than for the novel.(ABSTRACT TRUNCATED AT 400 WORDS)

Vestibular nerve and nuclei unit responses and eye movement responses to repetitive galvanic stimulation of the labyrinth in the rat.

Two-second cathodal current pulses were applied at one-minute intervals at a point external to the round window in the ear of each albino rat subject. Responses were recorded in the vestibular nerve ganglion, the vestibular nuclei (single units), or in the eye movements (search coil recording method) of anaesthetized, decerebrated, or alert rats. The unit responses to the galvanic stimuli were characterized and compared with responses to galvanic and rotational stimuli reported in the literature. The main focus of the study, however, was effects of stimulus repetition. In both the vestibular nerve and vestibular nuclei recordings, the responses of many units were substantially larger or smaller at the end of a 13-pulse stimulus train than at the beginning. In the vestibular nuclei, but not in the nerve, there was a slight bias towards a decrease in response magnitude, with 10/88 units showing decreases great enough to be considered as reflecting an habituation process. In contrast, the eye movement responses showed more consistent response decrements, especially in the alert condition, but also in the other conditions (none of the unit recordings were done in alert rats). It is concluded that some of the modifications underlying habituation of the vestibuloocular reflex probably occur in portions of the neuronal reflex pathways that are downstream from the vestibular nuclei.

Suprathreshold contrast perception as a function of spatial frequency.

Several studies have indicated that the exponent of the function relating perceived contrast to physical contrast is influenced by spatial frequency (e.g., Franzen & Berkley, 1975). This result has been called into question by other studies that have found the exponent to be unaffected by changes in spatial frequency (e.g., Gottesman, Rubin, & Legge, 1981). Possible artifactual reasons for the spatial frequency effect include failure to take into account range and stimulus repetition effects as well as contrast threshold differences. The present study examined the influence of spatial frequency on the relationship between perceived and physical contrast and controlled for these possible artifacts. Using a modulus-free version of magnitude estimation, judgments of perceived contrast were obtained from 7 observers at each of four spatial frequencies—.75, 4, 15, and 18 cycles per degree (cpd). When the data were fit with a threshold-corrected power function, an increase in the exponent of the perceived-contrast function was still observed at both low and high spatial frequencies, relative to a middle spatial frequency.

Cue enhancement by stimulus repetition: Natural and synthetic speech comparisons

This study investigates perceptual differences between natural and synthesized speech as measured by the effects of stimulus repetition on test item identification accuracy. The results show that identification accuracy is enhanced by repetition for natural speech but not for synthesis, suggesting that there are appreciable differences in their perceptual properties, at least inder the conditions of this experiment.

Effects of stimulus intensity on cardiovascular activity

A between-groups design (N = 75) was employed to investigate the effects of stimulus intensity and repetition on cardiovascular activity. It was predicted that as intensity increased, the pattern of physiological activity would change, indicating a transition from the orienting to the defense reflex. Cardiovascular activity was represented by measures of heart rate, digital pulse amplitude, and cephalic blood content. Subjects received 12 presentations of a 1000 Hz tone of 45, 60, 75, 90, or 105 dB. Stimulus risetime was 30 msec and the duration 2 sec. Analyses of variance revealed reliable effects of intensity and repetition on all cardiovascular variables. However, neither these results nor additional multivariate analyses supported the differentiation of orienting and defense reflexes as suggested by Sokolov (1963) or Graham (1979). The importance of the startle reflex in the interpretation of these findings was discussed.

Cephalic and digital vasomotor orienting responses: the effect of response localization, stimulus type and stimulus repetition.

Two studies are reported; the first dealing with vascular responses in the head area and in finger to tone, bell and mental arithmetic stimuli, the second, with the same responses to a series of 20 tones. Dilation responses from the head area were considerably less frequently obtained to pure tone than the other three stimuli, even on first exposure. This may account for some of the disparities in results between Eastern and Western European investigators. Habituation to tone from the head, and to a lesser extent from the finger, involved a shift from vasodilative to vasoconstrictive responses. However, a series of 20 tones was not sufficient to demonstrate habituation of the vasoconstrictive response. The shift from vasodilative to vasoconstrictive responses from the head area is not concordant with Sokolovian notions of the latter response being associated with defensive responses, unless one considers the possibility that the experimental situation becomes aversive over the experimental period. This possibility is explored in the paper.

An Alertness Decrement Hypothesis of Response Inhibition to Repeatedly Presented Stimuli

Both inhibitory and facilitative effects of repeated stimulus presentation have been observed. Two-factor theory attributes both kinds of effects to changes in specific components of attention. The theory claims that repeated exposure (a) decreases the alerting capacity of a stimulus and (b) facilitates encoding. The purpose of the present research was to provide further evidence that alertness decrement underlies the inhibitory effects of stimulus repetition. Adults were exposed to 30 presentations of a colored circle prior to performing a choice-reaction time (RT) task on which the targets were the familiarized stimulus and a novel stimulus. A warning signal occurred at one of three intervals prior to target onset. It was predicted from the literature on the temporal characteristics of alertness that the relative speed of responding to the familiarized stimulus would vary as a function of the warning signal-target interval. As predicted, responses to the familiarized stimulus were (a) slower than to the novel stimulus at intervals of 0 and 2,500 ms, but (b) faster than to the novel stimulus at 450 ms. The convergence of these findings with the alertness literature suggests an alertness decrement interpretation of response decrements to repeatedly presented stimuli.

Effects of stimulus intensity on cardiovascular activity.

ABSTRACTA between‐groups design (N = 75) was employed to investigate the effects of stimulus intensity and repetition on cardiovascular activity. It was predicted that as intensity increased, the pattern of physiological activity would change, indicating a transition from the orienting to the defense reflex. Cardiovascular activity was represented by measures of heart rate, digital pulse amplitude, and cephalic blood content. Subjects received 12 presentations of a 1000 Hz tone of 45, 60, 75, 90, or 105 dB. Stimulus risetime was 30 msec and the duration 2 sec. Analyses of variance revealed reliable effects of intensity and repetition on all cardiovascular variables. However, neither these results nor additional multivariate analyses supported the differentiation of orienting and defense reflexes as suggested by Sokolov (1963) or Graham (1979). The importance of the startle reflex in the interpretation of these findings was discussed.