Stimulus Presentation Rate Research Articles

Cortical slow negative waves following non-paired stimuli: Effects of modality, intensity and rate of stimulation

Using a simple stimulus counting task, negative after-waves following single (unpaired) stimuli were investigated under a variety of stimulus conditions. Responses were obtained to tones at 3 intensities, to light flashes at 3 intensities, and to tones at 3 rates of presentation. The acoustic stimuli led to a negative after-wave that peaked at frontal sites around 500 or 600 msec, and then trailed off to a more central scalp representation. This negative after-wave was increased in amplitude by slowing the rate of stimulus presentation. In comparison, no appreciable or sustained after-wave was elicited by visual stimuli. No significant effects in the negative after-wave were associated with intensity, either for visual or for acoustic stimuli. When analyzed by Principal Components Analysis, the negative after-waves were shown to comprise in all cases two underlying factors, although the factors contributed less to the total wave form for visual stimuli than for acoustic stimuli. Two interpretations for the negative after-wave were contrasted, one considering it to be an integral feature of the auditory evoked potential. A second interpretation, more compatible with the data obtained here, links the negative after-wave with non-specific activation processes.

Human auditory sustained potentials. II. Stimulus relationships

The auditory sustained potential recorded from the human scalp increases in amplitude with increasing stimulus intensity. At rapid rates of stimulus presentation its amplitude decreases but proportionately less so than the amplitude of the transient onset auditory evoked potential. The frequency specificity of this rate effect is complex, suggesting that there may be two underlying components of the scalp-recorded auditory sustained potential. The amplitude of the auditory sustained potential is smaller when the tonal frequency of the stimulus is higher. With prolonged stimulus durations there is some adaptation of the amplitude of the auditory sustained potential. This potential is larger in amplitude when sounds are presented binaurally than monaurally, and has a symmetrical coronal scalp distribution that is unaffected by the ear of stimulation.

Auditory brainstem recovery processes from birth to adulthood.

ABSTRACTTwo treatments‐by‐subjects with repeated measures experiments were performed to determine maturational changes in the recovery processes along the classical auditory pathway.Subjects ranged in age from birth to adulthood. Brainstem evoked potentials (BEPs) recorded from the surface of the scalp were obtained at stimulus presentation rates of 10–40/sec for all subjects. In addition, some newborns and adults received repetition rates of 50–80/sec.The amplitude and latency of selected BEP components which reflect discrete levels of brainstem integration, were measured. At stimulus rates of 10–40/sec strong age and rate effects evinced but significant interactions emerged only for those waves representative of rostral brainstem activity. A test of trend revealed that the newborns, in comparison with all other age groups, displayed slower recovery to increasing rates of stimulation (10–40/sec). The differential response of the individual BEP components conforms to the known caudo‐rostral maturation of the brainstem.Stimulus rates above 50/sec (50–80/sec) produced a relatively uniform depression (refractoriness) in the early BEP components irrespective of age. Only potentials generated in rostral structures continued to covary with rate of stimulation.These studies indicate that in the human brainstem the mechanisms responsible for neuronal recovery are essentially mature in the neonatal period.

Laterality, Attention and Rate Effects in the Auditory Temporal Discrimination of Chronic Schizophrenics: The Effect of Treatment with Chlorpromazine

Schizophrenic patients, non-psychotic patients and healthy subjects were required to detect longer target tones from a sequence of short tones presented to either ear. The rate of stimulus presentation and the frequency of switches between the ears were varied. The schizophrenic patients were examined for four weeks while on standard clinical doses of chlorpromazine, for four weeks while on placebo, and for four weeks following reinstatement of medication. Lateral asymmetries in the performance of the schizophrenics were found to diminish in proportion to both the duration and the dosage of medication. The results are consistent with the hypothesis that chlorpromazine causes an improvement of left hemisphere performance relative to the right. The performance of the schizophrenics, relative to that of comparison subjects, deteriorated as the rate of stimulus presentation increased, supporting the hypothesis that schizophrenics have particular difficulties in response selection or organization.

Stimulus presentation rate in vigilance.

Four groups of 12 subjects were run for two sessions to determine the influence of stimulus presentation rate in a monitoring task. Two stimulus rates were used, 12 and 60 per minute. Stimulus rate significantly affected detections on both days, but no transfer effect was found.

Sex, verbal ability, and pacing differences in serial learning.

Serial rote learning was examined as a function of sex, verbal ability (average and high), and stimulus presentation rate (4 and 10 sec.) among 64 individuals aged 60-79 years. At the fast pacing speed, the men with average skills produced fewer responses and performed less well than their female counterparts whose performance was similar to that of the high verbal men and women. The average men benefited the most from the slower pacing speed. No sex difference was found at the 10-sec presentation speed.

Effect of stimulus presentation rate upon visual threshold

Threshold measurements during dark adaptation are shown to be affected by the rate at which the threshold stimuli are presented. Thresholds for rods and for peripheral cones are raised by higher stimulus presentation rates, but thresholds for foveal cones are not. This difference for cones implies a previously unrecognized mechanism of visual sensitivity. The results are compared with the Troxler fading effect, and with earlier studies of light adaptation to intermittent stimuli.

Effects of Age and Stimulus Presentation Rate on Immediate and Delayed Recall in Children

SARVER, GARY S.; HOWLAND, ANN; and MCMANUs, TIMOTHY. Effects of Age and Stimulus Presentation Rate on Immediate and Delayed Recall in Children. CHILD DEVELOPMENT, 1976, 47, 452-458. The present study was designed to investigate the effects of stimulus presentation rate on recall and primacyrecency effects in children. A modification of the Digit Span task used in the Binet and Wechsler Intelligence Scales provided the basic memory task administered to 36 male schoolchildren in first, third, and fifth grades, The specific design required children to recall verbally serial strings of digits presented at various stimulus presentation rates. It was assumed that effective recall would be a function of general maturation and/or the development of cognitive strategies, and rate of stimulus presentation. Age, rate, and age x rate x recall condition (short or long term) were all significantly related to the number of digits correctly recalled. Results indicated that the traditional interpretation of the primacy effect as reflecting long-term memory store may not be valid.

Auditory processing speed and signal detection in schizophrenia.

Examined 2 differing explanations of schizophrenic processing deficit, J. Chapman and A. McGhie's (1962) and A. J. Yates's (see PA, Vol 41:10769). 32 18-46 yr old schizophrenics, classified on the acute-chronic and paranoid-nonparanoid dimensions, and 8 17-45 yr old neurotics were tested on 2 dichotic listening tasks. One task gave reaction time measures of processing speed at 3 rates of stimulus presentation; the other assessed stimulus detection and channel selectivity using theory of signal detection methods. Results support Yates and indicate that schizophrenics can attend successfully to 1 of 2 competing channels. Neither reduced sensory sensitivity nor response bias appeared to affect the performance of any group of Ss. Slowness of processing was a deficit characteristic of chronic, particularly nonparanoid, schizophrenics, although the factors responsible for this slowness remain a matter for empirical investigation. (25 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).

The interaction of rate and complexity of stimulus on the performance of adult aphasic subjects

A need for increased processing of auditory stimuli has been emphasized as a characteristic of aphasic patients. Clinical test performance of aphasics on tasks requiring various levels of communicative abilities was affected by rate of stimulus presentation. Stimuli were subtests of the Minnesota Test for Differential Diagnosis of Aphasia (MTDDA) presented at normal and slowed rates to aphasics grouped according to performance on the Porch Index of Communicative Abilities (PICA). Effect of rate on performance was influenced by severity of the disorder and complexity of the task required. Implications involve the clinician's attention to rate, presentation, and control of complexity of material.

Stimulus Repetition Rate and the Early Brainstem Responses

The effects of stimulus presentation rate on the various components of the cochlear and early brainstem response were investigated. In one experiment, examining stimulus rates 2 to 20 per second, a significant reduction in peak-to-peak amplitude with increasing rate was found only for the NP, response. In the second experiment, increasing the rate from 12 to 50 per second resulted in a significant decrease in all peak-to-peak amplitudes measured. Increasing the stimulus rate resulted in a significantly increased latency of alt waves except N5. The amount of latency change increased with successive waves.

Effects of layout of workplace on pupillary diameter.

Previous research by Poock (1973) indicated that, when Ss were required to process information under various rates of presentation, the pupil diameter increased in proportion to the rate of presentation when Ss were not mentally overloaded. However, when Ss were required to process information at rates above their maximum capacity (mentally overloaded), pupillary diameters decreased below normal resting baseline diameters. This paper uses the above results to examine the effects of stimulus-response spatial compatibility of layout of the workplace on pupillary diameter. Ten Ss, male and female, aged 12 to 36 yr., responded to the illumination of one of four small pen light bulbs by pushing one of four response keys to extinguish the illuminated light. The bulbs were approximately 15 in. in front of S and 1% in. apart in a horizontal orientation with response keys 2 in. directly below respective bulbs. Ss participated in random order in both of two experimental conditions: ( 1 ) compatible-where response key for a given light was the key directly beneath the light, (2) noncompatible-where another key other than the one directly below the light was designated as the proper response key. Maximum pupillary diameter was measured for resting baseline and experimental conditions with all noise and lighting parameters held constant in an environmental chamber. In both experimental conditions, the four equally probable lights (2 bits of information) were randomly and sequentially lighted starting with a rate of .5 lights per sec. (1 bit per sec.) for 15 sec. The presentation rate was then increased by .2 bits each succeeding 15 sec. until maximum pupillary diameter for a 15-sec. interval was below the initial baseline level, at which point S was considered mentally overloaded (Poock, 1973) and the experiment stopped. In the compatible stimulus-response arrangement, the pupillary diameter increased with stimulus presentation rate up to a rate of 3 bits per sec. at which point the pupil constricted below the baseline level. Likewise the constriction point for the noncompatible condition was 2.4 bits per sec. Application of the Wilcoxon matched-pairs signed-ranks test showed the presentation rate at the time of overload in the noncompatible arrangement to be significantly lower than in the compatible arrangement (p < .025).

Some variables affecting judgements of auditory temporal numerosity

Abstract Two experiments on judgment of auditory temporal numerosity are described. In Experiment 1 (n = 20) stimulus presentation rate and stimulus intensity were varied within Ss. Stimulus intensity was shown to affect the proportion of pulses reported, and the number of pulses reported per see of stimulus duration was shown to be related to stimulus presentation rate. In Experiment 2 (n = 40) a comparison was made of the effects of presentation rate and intensity in between-Ss and within-Ss experimental designs. The results show that the effects of these variables are determined by the type of experimental design employed. This finding seems in part attributable to incidental differences in stimulus context that follow from the use of the two different types of design.

Intra-modality selective attention and evoked cortical potentials to randomly presented patterns

The effects of selective attention on visually evoked cortical responses (VERs) were investigated under conditions where transient changes in arousal level and peripheral orienting factors were reduced to a minimum. Four subjects were presented a random series of relevant and irrelevant light flashes and were instructed either to count or to make a reaction time response to the relevant stimulus. Stimuli were presented at a constant rate of 0.92 or 1.92 c/sec. Subjects fixated a central reference point on the stimulus screen throughout each trial. Averaged VERs from the occipital region showed a consistent increased negativity at latencies of 220–250 msec and positivity at latencies of 290–340 msec when the stimulus was attended as compared to not attended. The effects of attention on VERs did not differ significantly as a function of the response conditions or rate of stimulus presentation. The effects of selective attention on early and late evoked cortical activity were discussed in terms of the processing of sensory information in the peripheral and central nervous system, respectively.

Effects of rate of stimulus presentation and penalty conditions on the discrimination learning of normal and retarded children.

Effects of rate of stimulus presentation and penalty conditions on the discrimination learning of normal and retarded children.

Level of arousal during Stroop performance: Effects of speed stress and “distraction”

Heart rate and respiration were obtained during Stroop performance. Although the test is often reported to evoke strong feelings of frustration, no evidence of increased autonomic arousal was found to be associated with the color-word interference effect, and this did not change with the addition of auditory “distraction.” Increasing stimulus presentation rate increased arousal, but this was independent of color-word interference.

Some Effects Of Stimulus Presentation Rate and Complexity on Perception and Retention in Brain-Damaged Patients

The short term memory recall performance of 36 brain-damaged subjects was compared with the performances of 36 mentally retarded subjects and 36 normal control subjects for both total responses correct and for order errors. Stimuli were presented to all subjects at three rates, 40, 60 and 120 significant units per minute, and at three levels of stimulus concept complexity, simple, compound, and complex, at each rate. While the brain-damaged subjects perform at a slightly lower level than normal control subjects, the pattern of their performance was similar to that of the control group and showed significant differences from the performance patterns of the mentally retarded group. The brain-damaged group did not make significantly more order errors than the normal control subjects, suggesting that their organization processes for stimuli icould “keep up” with the input of their reception processes. This was not true for the retarded who made significantly more order errors than both braindamaged and normal subjects under all conditions. A comparison of small groups of left and right hemisphere damaged subjects disclosed no differences in their ability to recall aurally perceived verbal material. The incidence of order errors was not related to Verbal IQ. Correlations were made of scores obtained from subjects on a memory test for visually perceived designs and the incidence of mirror-image errors with verbal memory and verbal order error scores. Mirror-image error scores were significantly and positively related to verbal order scores for the right hemisphere damaged subjects. This relationship did not exist between the scores for the left hemisphere damaged subjects.

Maximum capacity for sequential one-bit auditory decisions.

Studied the maximum intrinsic rate of channel intermittency for sequential decisions in 9 21-30 yr. old Ss, each submitted to about 30 runs of a simple, externally paced task. Any run consisted of a series of 150 stimuli delivered at a regular interval between 2 and .15 sec. 50% of the stimuli were nonsignal clicks randomly mixed with the signal clicks (20-30 db. higher in intensity) to which S was asked to press a Morse key. Analysis of data on hits and false alarms showed that the achieved decisional rate started to lag behind the required rate at about 1.1/sec and it reached a maximum for rates of stimulus presentation of 3-5/sec. The mean maximum rate of correct decisions under such steady-state sensory overload was estimated by 4 methods as 2.15, 2.33, 2.64, and 2.64/sec. The maximum rate is related to decisional rather than to motor effector limitations and may reflect a basic perceptual mechanism of the brain, as suggested from correlative studies on cerebral evoked potentials. (21 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1970 American Psychological Association.

Differential effects of interstimulus interval on habituation and recall scores

Habituation of the orienting reflex (OR) may be viewed as a simple or model form of learning. Previous research (Germana, 1968) has demonstrated that habituation of the OR may take the form of conventional stimulus-response learning and suggested the present comparison between habituation and a behavioral recall measure. Habituation to a 10-digit number was an inverse function of interstimulus interval (ISI), whereas recall of the same stimulus, tested after habituation, did not significantly vary across the range of ISIs employed. It was suggested that the effects of ISI on habituation were primarily determined by increased difficulty of encoding rate of stimulus presentation at increasingly longer ISIs and that behavioral recall does not reflect this temporal dimension of stimulus learning.

Stimulus presentation rate and level of intellectual competency

The ability of retarded and normal adult Ss to follow instructions presented auditorially at three rates of speed was examined. Faster rates of stimulus presentation adversely affected the performance level of both groups in recalling and pointing to sequentially ordered concepts of size, color and form. The group of retarded Ss listening to instructions presented at the fastest rate had a significantly lower level of performance than the retarded Ss hearing instructions presented at the slowest rate.