Order Of Stimulus Presentation Research Articles

Effects of intensity and order of stimuli presentation on AEPs: an analysis of the consistency of EP augmenting/reducing in the auditory modality

Objectives: (1) To achieve a better understanding of the intensity dependence function of AEPs recorded at fronto-central and temporal electrode sites; (2) To assess the possible influence of the order of stimuli presentation on this function; and (3) To investigate if a subject's AEPs augmenting or reducing (A/R) tendency is consistent throughout two intra-session runs. Methods: Two sequences of 288 stimuli of different intensities (60, 80, 90 and 110 dB SPL) were delivered to 29 psychology students. In the first run, stimuli were presented in 4 consecutive blocks of 72 tones of each intensity, either in an ascendant (from lowest to loudest stimuli) or descendent (from loudest to lowest) way. In the second run, a pseudo-randomized sequence of stimuli of the 4 intensities was presented. Results: (1) AEPs recorded at fronto-central electrodes showed a stronger intensity dependence than those recorded at temporal leads; (2) The delivery of tones of different intensities in an aleatory sequence provoked higher amplitudes at Fz and Cz – especially for the loudest tones – but not at temporal leads; (3) The individual's AEP responses to stimuli of increasing intensity are highly consistent throughout two intra-session runs. Conclusions: The different findings obtained for the fronto-central N1P2 and the T complex in relation to the effect of intensity and order of stimuli presentation may be explained in terms of the cortical origin of those components. The higher amplitudes found with an aleatory sequence, especially for the highest intensity stimuli, may reflect that these stimuli capture the subject's attention and provoke an enhancement of the N1 component. The implications of the present results for investigation into A/R and the clinical relevance of this phenomenon are discussed.

The relationship between the uncomfortable loudness level and the acoustic reflex threshold for pure tones in normally-hearing and impaired listeners--a meta-analysis.

The objective of this study was to determine the potential of the acoustic reflex threshold (ART) as a predictor of the uncomfortable level (ULL) and to identify related areas for investigations in the future. Eleven studies reporting data from 141 normally-hearing and 240 impaired hearing subjects have been reviewed, focusing on methods, test conditions and subjects. Results and conclusions are discussed and new calculations have been performed on the reported data. The median difference between ART and ULL across studies and frequencies was 5 dB both in normally-hearing and impaired subjects. Some authors argue, that although a close relationship of mean values of the two measurements may exist, prediction of the ULL based on ART measurement will be inaccurate because of high inter-subject variability. A statistically significant correlation exists between the mean HTL, the mean ART and the mean ULL in impaired hearing, while a relationship between the mean ART and the mean ULL does not exist in normal hearing. Based on pooled data across frequencies from the reviewed studies the mean ULL= (0.64 x mean ART+38) dB HL. The discrepancies between the results found in the reviewed studies may be explained by different instructions and stimulus presentation orders when assessing the ULL, difficulty in assessing the sound pressure level in the ear canal, influence of varying background noise levels and different admission criteria. It is recommended that the relationship between different loudness levels and the ART be investigated in normally-hearing subjects and in subjects with different levels of impairment, using standardized instructions. To further provide uniformity of the test material groups should be selected according to history of middle ear diseases and the use of hearing aids.

562 Effect of stimulus intensity and order of stimuli presentation on auditory evoked potentials (AEPS). An analysis of the consistency of augmenting / reducing (A / R) phenomenon

562 Effect of stimulus intensity and order of stimuli presentation on auditory evoked potentials (AEPS). An analysis of the consistency of augmenting / reducing (A / R) phenomenon

The effect of complex motion pattern on speed perception

We recently reported a new motion illusion where dots in expanding random dot patterns appear to move faster than those in rotation patterns despite having the same physical speed distributions. In the current paper, we compared expansion and rotation motion to translational motion and found that the perceived dot speed in translation patterns was between that of expansion and rotation. We also explored contraction motion and found subjects perceived dots in contracting patterns as moving slightly faster than those in expanding patterns and much faster than those in rotating patterns. Finally, we found that stimulus presentation order in a trial plays an important role in determining the magnitude of the speed illusion—the effect is greater when the subjectively faster stimulus is viewed second (e.g., expansion after rotation). The dependence on stimulus order is greatest when comparing complex motion patterns with large subjective speed differences. This phenomenon is unlikely to be explained in terms of channel fatigue or adaptation.

Spatial extinction on double asynchronous stimulation

Despite the fact that visual extinction is widely considered a space-based disturbance of selective attention, there has been little theoretical consensus about the nature of its pathogenic mechanism. A specific disruption in the ability to disengage attention from ipsilesional stimuli, or a loss of weight with which contralesional objects compete for visual selection, have been hypothesized to account for the disorder. We tested the merits of these two explanations in a right-hemisphere-lesioned patient. FB, who failed to recognize a contralesional target only when it was shown concurrently to an ipsilesional target (i.e. visual extinction). His task was to report two target letters presented in rapid succession to the left and right of the fixation point. The order of stimulus presentation (Left-First vs Right-First), and the intertarget interval (stimulus onset asynchrony) were varied systematically. We showed that contralesional extinction may occur for successively presented targets, not just for stimuli displayed at the same time. Of most importance, FB was seriously and equally impaired in dealing with a contralesional stimulus when this either preceded the ipsilesional stimulus or followed it by an interval less than about 600 msec. The data appear to contradict the disengagement hypothesis, which predicted a substantial reduction of extinction when a stimulus was displayed first into the lesioned side of space. We suggest that a competitive model of visual selective attention fits the data quite well.

Recognition of Chord Changes by 4- and 5-Year-Old American and Argentine Children

The purpose of the study was to investigate young children's abilities to discriminate between two chords played as the accompaniment of a melody and played alone with no melody. After receiving brief training in harmonic discrimination, 167 children ages 4 and 5 from four preschools were tested in their ability to discriminate between the chords “I” and “V6/5” in the song “En la Torre de una Iglesia” or between the chords “i” and “VII” in “Drunken Sailor.” ANOVAs with repeated measures were performed for age, school, order of stimulus presentation (within variable), and type of stimulus on children s scores for each song. Both analyses indicated that age, type of stimulus, and the interaction of these two variables affected children's performance in the test significantly. In addition, order of presentation was found to be a significant variable of children's scores for the song “Drunken Sailor.” Five-year-olds could detect harmonic changes in simple chord progressions, but were unable to do so when a melody was superimposed over the progression. Four-year-olds could not identify the chord changes of either stimuli.

Wing quivering of black-capped chickadees with nestlings: invitation or appeasement?

Discrimination between conspecifics is important in mediating social interactions between several individuals in a network environment. In great tits, Parus major, females readily distinguish between the songs of their mate and those of a stranger. The high degree of song sharing among neighbouring males, however, raises the question of whether females are also able to perceive differences between songs shared by their mate and a neighbour. The great tit is a socially monogamous, hole-nesting species with biparental care. Pair bond maintenance and coordination of the pair's reproductive efforts are important, and the female's ability to recognize her mate's song should therefore be adaptive. In a neighbour–mate discrimination playback experiment, we presented 13 incubating great tit females situated inside nestboxes with a song of their mate and the same song type from a neighbour. Each female was tested in two trials with the opposite order of stimulus presentation. Eleven females responded to the song of their mate in both trials, while two females responded to those of their mate in one trial and a neighbour in the other. Thus, great tit females are able to perceive subtle individual differences between their mate's song and a neighbour's rendition of the same song type despite being inside nestboxes, which are known to alter the received song structure and intensity. We suggest that this female discrimination ability inside nest holes is mediated by a high perceptual sensitivity towards small variations in song structure that should be adaptive to this hole-nesting bird species.

Human evaluative conditioning: order of stimulus presentation.

In an experiment designed to demonstrate evaluative conditioning, subjects were shown 48 pictures of sculptures that they rated on a scale with 21 categories (-10 to +10). Then, the two most liked pictures (L) were paired with pictures from the categories -1, 0, or +1 (N). In contrast to prior experiments, subjects were given either forward conditioning (N-L) or backward conditioning (L-N) trials but not both. Four other neutral stimuli were paired with each other (N-N) and acted as control stimulus pairs. After conditioning, the stimuli were rated a second time. There was a statistically significant difference in evaluative ratings showing a change of the evaluative tone of the previously neutral stimuli in a positive direction only after forward conditioning. This finding is inconsistent with results of prior experiments and challenges the assumption of Martin and Levey (1987) that evaluative conditioning is different from human classical conditioning.

Lack of an order effect in brief contact taste tests with closely spaced test trials

The number of licks during 30-s exposures to a range of concentrations of sucrose, glucose, fructose, maltose, and Polycose were recorded. A complete series of concentrations of each carbohydrate was offered in ascending, descending, or random order with 30-s intertrial intervals. The order of presentation differed on different days. For sucrose, glucose, fructose, and maltose the number of licks in the 30-s periods was an increasing monotonic function of concentration regardless of the order of stimulus presentation. For Polycose, the lick rate-concentration function was an inverted U-shaped function of concentration with a peak on the 0.1 M to 0.2 M range. In all cases the rate of licking declined during the 30-s exposure period, suggesting the development of gustatory sensory adaptation. The results indicate that it is possible to obtain a rapid assessment of the taste sensitivity of the rat to a variety of carbohydrate solutions on a single day with very brief intertrial intervals.

The influence of the information value provided by prior-cuing treatment on the reactivation of memory in preweanling rats

In two experiments, the influence of exposure to a CS− on the acquisition and retention of a conditioned odor aversion was examined. Preweanling rats were given exposure to the CS− either prior to (CS−/CS+) or following (CS + /CS−) the pairing of a second odor (the CS+) with footshock. The results of Experiment 1 indicated that subjects in both of the treatment conditions acquired aversions of comparable strength to the odor paired with footshock and that retention of the odor aversion was not affected by order of stimulus presentation during conditioning. Experiment 2 indicated, however, that the effectiveness of pretest exposure to various elements of the conditioning episode in reactivation of the memory for conditioningwas dependent on the order of stimulus presentation during conditioning. This differential effectiveness of the various reactivation treatments is discussed in terms of their relationship to the associative “status” of the stimuli present during conditioning and in terms of the information provided to the animal by the reactivation treatment.

Time-of-day-induced priming effects on verbal and nonverbal dichotic tasks in male and female adult subjects.

Normal adults (32 males and 32 females) were tested for time-of-day related shifts in laterality and priming on two dichotic listening tasks using consonant-vowel combinations (CVs) and musical melodies. The predicted time-of-day effect on melodies was due to males showing low report in the morning, but not the afternoon, suggesting increased right hemisphere involvement in the afternoon. A time-of-day-induced priming effect on the laterality index for CVs differentiated males and females. Males tested morning-first were more lateralized than females, who in turn were more lateralized when tested afternoon-first. A time-of-day-induced priming effect on the laterality index for music indicated those tested afternoon-first showed an overall left ear advantage (LEA), whereas those tested morning-first showed an overall right ear advantage (REA). On raw music scores a sex-linked, time-of-day-induced priming effect was due to the prior presentation of CVs--that is, cognitive priming. Other priming effects on music were evident for order of stimulus presentation and order of ear attended. Implications for theory, research and pedagogy are discussed.

Responses of monkey medullary dorsal horn neurons during the detection of noxious heat stimuli.

1. We examined the activity of thermally sensitive trigeminothalamic neurons and nonprojection neurons in the medullary dorsal horn (trigeminal nucleus caudalis) in three monkeys performing thermal and visual detection tasks. 2. An examination of neuronal stimulus-response functions, obtained during thermal-detection tasks in which noxious heat stimuli were applied to the face, indicated that wide-dynamic-range neurons (WDR, responsive to innocuous mechanical stimuli with greater responses to noxious mechanical stimuli) could be subclassified based on the slope values of linear regression lines. WDR1 neurons exhibited significantly greater sensitivity to noxious heat stimulation than WDR2 neurons or nociceptive-specific neurons (NS, responsive only to noxious stimuli). 3. In one behavioral task, the monkeys detected 1.0 degrees C increases in noxious heat from preceding noxious heat stimuli ranging from 44 to 48 degrees C. WDR1, WDR2, and NS neurons increased their discharge frequency as a function of the intensity of the first noxious heat temperature (T1) as well as the final temperature (T2). The responses of WDR1 neurons were greater than those produced by WDR2 or NS neurons across all the temperatures examined. The order of stimulus presentation affected the responses of WDR1 neurons to 1.0 degrees C increases in the noxious heat range but not those of WDR2 or NS neurons. 4. In a second behavioral task, the monkeys detected small increases in noxious heat (0.2-0.8 degrees C) from a first temperature of 46 degrees C. Although the responses of all three classes of neurons were monotonically related to stimulus intensity, WDR1 neurons exhibited greater sensitivity to small temperature increases than either WDR2 or NS neurons. 5. Subpopulations of all three classes of neurons exhibited responses that were independent of thermal stimulus parameters or sensory modality and that only occurred during the behavioral task. These task-related responses were time-locked to specific behavioral events associated with trial initiation and trial continuation. 6. These data provide evidence that a subpopulation of WDR neurons is the dorsal horn cell type most sensitive to small increases in noxious heat in the 45-49 degrees C temperature range and provides the most information about stimulus intensity. The findings support the view that nociceptive neurons have the capacity to precisely encode stimulus features in the noxious range and that WDR neurons are likely to participate in the monkeys' ability to perceive the intensity of such stimuli.

AN ANALYSIS OF SEVERAL VARIABLES INFLUENCING THE EFFICACY OF FLASH CARD INSTRUCTION

We conducted four experiments using an alternating treatments design to assess the influence of several variables on children's acquisition of number facts during one-on-one flash card instruction. In Experiment 1, we manipulated the order of stimulus presentation; in most cases a higher percentage of correct responses occurred, and mastery criterion was reached in somewhat fewer sessions, when a missed problem was re-presented after the next item than when problems were re-presented in a sequential order. In Experiment 2 a comparison of error-contingent reprimands with no reprimands yielded similar results in favor of the former procedure. Experiment 3 indicated that a higher percentage of correct responses and more rapid acquisition occurred when the tutor and student were seated knee-to-knee than when a desk was positioned between them. Experiment 4 compared the rate of learning in the presence and absence of a treatment package consisting of all three variables identified as leading to more rapid learning in the previous three experiments. Children reached criterion in less than half the time when the treatment package was in effect.

Infant Discrimination of Naturalistic Emotional Expressions: The Role of Face and Voice

The ability of infants to discriminate dynamic, multimodal expressions of emotion was assessed in a series of 5 experiments. In Experiment 1, 48 infants of 4 and 5 months (total N = 96) were habituated to color/sound videotapes of 6 women speaking the same script sadly or happily. Following habituation, 2 new women were presented, each speaking once in the familiarized emotion and once in the novel emotion. Order of stimulus presentation (Sad----Happy, Happy----Sad) was counterbalanced. 5-month-olds were able to discriminate the expressions in both directions, whereas 4-month-olds could discriminate them only in the Sad----Happy direction. In Experiment 2, the ability of 5- and 7-month-olds to discriminate happy and angry expressions was examined using the Happy----Angry stimulus order alone. Only the 7-month-olds could differentiate these stimuli. In Experiment 3, it was shown that 7-month-olds could not distinguish these same Happy----Angry stimuli without vocal accompaniment. The purpose of the fourth experiment was to determine whether the voice played an equally important role in the Sad----Happy discrimination of Experiment 1. Surprisingly, a 5-month group tested without voice readily discriminated these stimuli. Finally, the fifth experiment sought to determine whether an Angry----Happy comparison might also be discriminable without voice. A 7-month group tested in this manner could not discriminate these expressions, while a group tested with voice could. The results indicate that infants can differentiate dynamic, multimodal expressions as early as 5 months, that they distinguish dynamically distinct expressions earlier than more similarly animated expressions, and that they seem to rely more on the voice than the face in making these discriminations.

Infant Discrimination of Naturalistic Emotional Expressions: The Role of Face and Voice

The ability of infants to discriminate dynamic, multimodal expressions of emotion was assessed in a series of 5 experiments. In Experiment 1, 48 infants of 4 and 5 months (total N = 96) were habituated to color/sound videotapes of 6 women speaking the same script sadly or happily. Following habituation, 2 new women were presented, each speaking once in the familiarized emotion and once in the novel emotion. Order of stimulus presentation (Sad----Happy, Happy----Sad) was counterbalanced. 5-month-olds were able to discriminate the expressions in both directions, whereas 4-month-olds could discriminate them only in the Sad----Happy direction. In Experiment 2, the ability of 5- and 7-month-olds to discriminate happy and angry expressions was examined using the Happy----Angry stimulus order alone. Only the 7-month-olds could differentiate these stimuli. In Experiment 3, it was shown that 7-month-olds could not distinguish these same Happy----Angry stimuli without vocal accompaniment. The purpose of the fourth experiment was to determine whether the voice played an equally important role in the Sad----Happy discrimination of Experiment 1. Surprisingly, a 5-month group tested without voice readily discriminated these stimuli. Finally, the fifth experiment sought to determine whether an Angry----Happy comparison might also be discriminable without voice. A 7-month group tested in this manner could not discriminate these expressions, while a group tested with voice could. The results indicate that infants can differentiate dynamic, multimodal expressions as early as 5 months, that they distinguish dynamically distinct expressions earlier than more similarly animated expressions, and that they seem to rely more on the voice than the face in making these discriminations.

ルール観察学習における反応不確実性について 観察学習におよぼす前経験の効果

The present study was conducted to examine the hypothesis that children's feelings of uncertainty would mediate between pre-experience and rule acquisition in observational learning. After received a pretest, subjects were requested to estimate their response uncertainty concerning a task used in the pretest. Then they observed a model responding to a series of pictures each of which depicting one of four directions. The model's responses were governed by a rule consisted of two dimensions: the progression and the direction. After observing the demonstration, subjects received two post-tests which differed in the order of stimulus presentation and in terms of the reinforcement. Subjects enhancing their feelings of uncertainty in the pretest phase acquired a rule which contained a dimension of the progression, while subjects who did not enhance them acquired a rule used by the model. These findings were interpreted as generally supporting the hypothesis of response uncertainty as a mediator of rule learning.

The Effects of Order of Stimulus Presentation on Ratings of Counseling Performance

This study was designed to examine the effects of order of stimulus presentation on observer ratings of counseling performance. Two videotaped counseling simulations, determined by judges to represent either high or low quality performance, served as the stimuli. Participants were randomly assigned to one of two levels of the order effect: Group 1 viewed the videotape with low quality performance first, followed by the high quality performance videotape; Group 2 viewed the high quality performance videotape first, followed by the low quality performance videotape. Four widely used measures of counseling performance served as dependent measures. Results revealed a statistically significant interaction between quality of performance and the order in which the performances were rated.

The Generalized Discrimination of Facial Expressions by Seven-Month-Old Infants

2 experiments were conducted to examine 7-month-old infants' perception of the facial expressions happy and fear. Using a paired-comparison procedure, infants in the first experiment were able to generalize their discrimination of these 2 expressions across the faces of 4 male and female models if they were first presented with the set of happy faces, but not if they were first presented with the set of fear faces. A second experiment was conducted to examine the source of the stimulus presentation order effect. Here a second group of 7-month-old infants was presented with a single male or female face posing both the happy and fear expressions simultaneously. The results revealed significantly longer looking to the fear face. This preference to look at fear faces is discussed, as are its implications for studies of expression recognition in general.

Phonotaxis in the cricket,Gryllus bimaculatus DeGeer: comparisons of choice and no-choice paradigms

1. The phonotactic tracking behavior of females on a locomotion compensator was studied in the field cricket,Gryllus bimaculatus DeGeer. Synthetic stimuli were played back in choice and no-choice experiments to determine the behavioral tuning to calling song temporal properties. 2. In ‘to-and-fro’ sequential tests, best tracking occurred when stimuli had syllable periods between 35 and 50 ms (Figs. 2, 3). The variability of tracking scores within and among individuals was lowest when syllable periods were 40 and 45 ms, indicating an even narrower tuning to syllable period. 3. Context-dependent after-effects were seen in some females (Figs. 2, 3). That is, the range of syllable periods tracked by females in sequential experiments was broad or narrow, depending upon the order of stimulus presentation (i.e. from ‘unattractive’ to ‘attractive’ syllable periods or vice versa (see Fig. 3)). 4. In choice experiments, the optimal range of syllable periods was similar to that found in to-and-fro sequential (no-choice) experiments. As the syllable period of the alternative stimulus was moved farther away from that of the standard stimulus (45 ms), the preference for the standard persisted even when its SPL was attenuated by5 to 20 dB relative to the SPL of the alternative (Fig. 4). 5. Several females tracked both the standard and alternative stimuli in sequential ‘pre-tests’, but clearly preferred (tracked) the standard over the alternative in subsequent choice tests (Figs. 5–9). This difference in the results of choice and nochoice experiments was most prominent when the alternative syllable period was between 55 and 60 ms (Fig. 10). These results can be explained by recent findings of trade-off phenomena in calling song recognition inG. bimaculatus.

The effects of trait label and order of presentation on observers' ratings of performance anxiety

In two experiments, the effects of different stimulus presentation orders and trait labels on observers' ratings of performance anxiety were examined. In Experiment 1, 60 college students viewed, in one session, ten 3-min videotapes of a man speaking while displaying a variety of the behavioral manifestations of anxiety. The tapes varied linearly in the percentage of time during which anxious behaviors were emitted. Anxiety ratings were made along either a “calm” or an “anxious” dimension. Subjects were randomly assigned to one of three orders of presentation conditions (with the frequencies of anxious behaviors ascending, descending, or randomized across tapes) and one of two trait-label conditions, calm or anxious. In Experiment 2, 60 additional subjects viewed these same tapes and a contrasting series designed to display a consistent rate of anxiety behaviors. These tapes were viewed in 10 sessions over a 2- to 5-week period. Results replicated prior studies showing that the order of presentation can significantly affect observers' ratings. Additionally, the results suggested that, under certain conditions, subjects may not perceive a conceptually dichotomous variable (e.g., calm vs. anxious) in the same way. These results are discussed in terms of the complexity of observer behavior and potential problems in comparing outcome studies that use dichotomous traits.