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A T Cacace

Publications and source records attributed to A T Cacace.

17 recordsLinked to original sources
PubMed1992

Assessing short-term recognition memory with forced-choice psychophysical methods.

The rationale and methodology for using computer-controlled forced-choice psychophysical methods to assess short-term recognition memory in human subjects are presented. Here, we use non-verbal computer-synthesized auditory and visual stimuli with an adaptive psychophysical procedure. Sequence-length thresholds (SLTs, span lengths) for randomly generated binary auditory and visual-sequential patterns and simultaneous visual-spatial patterns are determined to assess short-term memory capacity. The SLTs can also be used to equate for initial retention level for delayed matching-to-sample (DMS) or delayed matching-to-non-sample (DMNS) tasks which assess memory decay. The DMS/DMNS tasks have also been modified for use with the forced-choice paradigm. In contrast to many verbal paradigms requiring immediate ordered recall, non-verbal stimuli in a forced-choice paradigm provide a more direct measure of sensory memory because long-term memory, complex encoding/decoding processes, and motor-sequencing factors are minimized or avoided. Furthermore, the forced-choice recognition memory tasks are applicable over a broad age range, are less sensitive to socio-economic factors and educational level, and avoid complex instructions. Taken together, these factors enhance the applicability of these tasks in children and adults with CNS lesions, particularly where cognitive status may be compromised.

Acoustic Stimulation↗
PubMed1992

Swallowing disorders in a population of children with cerebral palsy.

One of the disabilities in patients with cerebral palsy (CP) is dysphagia. To establish the prevalence of dysphagia in a population of children with CP, and to determine if any factors are related to dysphagia, we studied 56 CP patients, 5-21 years, enrolled in a primary school for the disabled. Fifteen patients (27%) had either radiographic or clinical evidence of dysphagia. These 15 patients were compared to the remaining 41 patients without dysphagia. Using data obtained from chart review and interviews with speech pathologists, several factors that contributed to dysphagia were found. These included: bite reflexes, slowness of oral intake, poor trunk control, inability to feed independently, anticonvulsant medication, coughing with meals, choking, and pneumonia. We also noted trends in the following factors: presence of tongue thrusting, presence of drooling, severity of CP, poor head control, severity of mental retardation, seizures, and speech disorders. Factors not related to the presence of dysphagia include: subject age, cause of CP, and type of CP. Early, aggressive work-up and identification in CP patients with the risk factors outlined above can reduce the associated pulmonary complications.

Adolescent↗
PubMed1992

Short-term poststimulatory response characteristics of the human acoustic stapedius reflex: monotic and dichotic stimulation.

Two experiments were performed to study short-term poststimulatory response characteristics of the human acoustic stapedius reflex in the time and intensity domains. In experiment 1, monotic magnitude-intensity functions (MIFs) were obtained for a 20-ms test stimulus preceded by a conditioning stimulus varying in duration (20, 50, 100, 500 ms) and level (-10, 0, +10 dB re: stapedius-reflex threshold) and temporally separated from the test stimulus by various interstimulus intervals (ISIs) (0, 20, 50, 100, 500 ms). Experiment 2 was similar in design except that conditioner and test stimuli were presented dichotically and fewer ISIs were used. Both experiments demonstrated that a prior conditioning stimulus produced significant increases in test-stimulus response magnitude. These poststimulatory effects were characterized by complex interactions among stimulus variables (conditioner duration, conditioner level, and interstimulus interval) with similar interactions occurring for both monotic and dichotic stimuli. A simple superposition effect of the responses to the conditioner and test stimulus does not account for the effect of prior stimulation since responses often exceeded the sum of the responses to the conditioner and the test stimulus alone.

Acoustic Stimulation↗
PubMed1992

Aspects of short-term acoustic recognition memory: modality and serial position effects.

Two experiments were performed to study short-term acoustic recognition memory using synthesized binary tone patterns within a three-interval, three-alternative forced choice psychophysical procedure. In Experiment 1, subjects showed as significant performance advantage in processing binary frequency patterns over intensity and duration patterns. In Experiment 2, we found that elements at the beginnings and ends of various length frequency pattern sequences were recognized better than those in the middle of the sequence (primacy and recency effects). Furthermore, we showed that performance on a serial position task may be a useful tool to demonstrate the limited capacity of information storage in acoustic short-term memory. Sensory memory typically has been examined using verbal stimuli and requiring immediate ordered recall. These results demonstrate the utility of studying sensory memory using complex nonverbal stimuli within a forced-choice recognition paradigm.

Acoustic Stimulation↗
PubMed1992

Acoustic pattern recognition and short-term memory in normal adults and young children.

Our experiments were aimed at determining if the delayed matching-to-sample paradigm (DMS) could be used to study short-term acoustic recognition memory in young children and whether or not differences exist between children and adults. Our results indicate that the DMS paradigm can produce reliable data in young children. The decay of acoustic information over time was equivalent in both children and adults, beginning at about 1 s and lasting for longer than 10 s. With 7-element acoustic frequency-pattern sequences, a performance difference between children and adults was observed which appears explicable on the basis of longer memory spans in the adult subjects. When we equated for span length, this effect was no longer apparent.

Acoustic Stimulation↗
PubMed1991

Threshold and suprathreshold temporal integration effects in the crossed and uncrossed human acoustic stapedius reflex.

Threshold and suprathreshold temporal integration (TI) effects were studied in the crossed and uncrossed human acoustic stapedius reflex. Changes in reflex threshold were compared at four stimulus durations and for six threshold response criteria; suprathreshold effects were similarly compared at four stimulus durations and at five stimulus sound-pressure levels. Our results showed that reflex thresholds were significantly lower for the uncrossed condition and for longer duration stimuli. Both effects were dependent on threshold response criteria. Threshold TI measurements in both crossed and uncrossed conditions were equivalent at low criterion levels (0%-4%, p greater than 0.05) but were significantly larger in the crossed condition at higher criterion levels (5%-6%, p less than 0.05). Prominent suprathreshold effects also occurred. The main effect was characterized by significantly larger reflex magnitudes in the uncrossed condition. Duration dependent slope differences in magnitude intensity functions (MIFs) were also observed and were characterized by steeper slopes for longer duration stimuli. Saturation effects and/or intensity-dependent slope decelerations in MIFs were predominant in the uncrossed condition and for stimulus durations exceeding 20 ms. These data provide further quantitative evidence for asymmetric threshold and suprathreshold response properties of the crossed and uncrossed human acoustic stapedius reflex and demonstrate the dependence of these effects on stimuli of different durations.

Acoustic Stimulation↗
PubMed1988

T complex hemispheric asymmetries: effects of stimulus intensity.

The T complex component of the human auditory evoked potential (AEP) is thought to be produced in auditory cortex, on the posterior lateral surface of the temporal lobe. Recorded over temporal scalp, it consists of an 80-90 ms positive peak, Ta, and a 120-140 negative peak, Tb. As part of an effort to develop the clinical usefulness of the T complex in assessing auditory cortical function, we studied the effects of change in monaural stimulus intensity (20-80 dB SL) on T complex latency, amplitude, and hemispheric differences in normal adults. Ta and Tb peak latencies decreased as stimulus intensity increased. These latency changes were not dependent on ear or hemisphere. Right hemisphere Ta latency was shorter with contralateral than with ipsilateral stimulation; while left hemisphere Ta latency was not dependent on the ear stimulated. Tb latency was shorter over the left hemisphere, and over the contralateral hemisphere. Ta-b amplitude increased as stimulus intensity increased. This amplitude change was not dependent on ear or hemisphere. Ta-b amplitudes were larger over the right hemisphere and over the contralateral hemisphere. Hemispheric asymmetries were not significantly affected by stimulus intensity.

Adolescent↗
PubMed1986

Some poststimulatory effects on the whole nerve action potential.

Short-term poststimulatory effects on the N1 component of the auditory-nerve compound action potential (CAP) were investigated in Mongolian gerbils. Some effects of conditioner level, conditioner frequency and probe level were assessed. In most cases, poststimulatory decrements occurred. The decrements were independent of probe intensity when the conditioner was close in frequency and of equal or less intensity than the probe. At some other conditioner frequencies, decrements decreased as probe intensity increased. Departures from these relationships occurred when a more intense conditioner was applied. In some instances, increases in CAP amplitude were also observed. The roles of single unit responses including spread of cochlear excitation, and possible mechanisms for poststimulatory facilitation are discussed.

Acoustic Stimulation↗
PubMed1985

Level effects in complex stimulus discrimination.

The dependence of spectral-shape discriminations upon presentation level was studied using stimuli consisting of a bandpass noise and a less intense pure tone. The level of the noise band was held constant (+10 dB) relative to the level of the tone, and the minimum change in the intensity of the tone was measured across a range of presentation levels. The results demonstrated that, for tonal frequencies located near the upper edge of the noise band, subject's optimal performance occurred at intermediate presentation levels and became considerably poorer at high levels. This result is in accordance with upward spread of masking and emphasizes that presentation level is an important parameter to consider when measuring discriminations of complex spectral shapes.

Acoustics↗
PubMed1985

On the loudness of complex stimuli and its relationship to cochlear excitation.

Two experiments were conducted to reexamine the relation between loudness and the bandwidth of complex stimuli. In experiment 1, experimental stimuli consisting of a 2000-Hz pure tone and ten computer-generated multitonal complexes ranging in bandwidth from 0.26-3.16 oct, logarithmically centered at 2000 Hz, were matched in loudness to a 2000-Hz comparison pure tone presented at 90, 70, and 30 dB SPL. The SPL of the experimental stimuli required for equal loudness was linearly related to bandwidth (in octaves) for each of the three comparison stimulus levels. In experiment 2, the loudness behavior of narrow-bandwidth stimuli within the previously reported critical band region was examined. The results indicated a linear relation similar to that obtained in experiment 1. These results are consistent with an auditory filter concept in which frequency is continuously encoded along the basilar membrane and in which loudness of complex stimuli is linearly related to area of excitation.

Acoustic Stimulation↗
PubMed1983

Late auditory evoked potentials can occur without brain stem potentials.

The sequence of early, middle and late auditory evoked potentials is well known. However, it is unknown whether the late (60-250 msec) potentials can occur independently of the early, brain stem potentials. Therefore, in 6 subjects with markedly abnormal or absent brain stem potentials, we recorded two of the late potentials: the vertex potential and the T-complex. The latter is a putative product of auditory cortex. Both of these potentials were clearly evident in all patients in spite of the absence of or marked abnormalities in brain stem potentials.

Brain Stem↗
PubMed1979

Abnormal auditory evoked potentials in hereditary motor-sensory neuropathy.

From a kinship with a dominantly inherited motor-sensory neuropathy, we studied 2 brothers with brainstem auditory evoked potentials and behavioral audiometric tests. They had abnormal prolongation of I-III interpeak intervals. Wave V was poorly developed. Conventional audiometric tests did not reveal a peripheral hearing loss. It is probable that their auditory nerves and spiral ganglia are undergoing a pathophysiological process analogous to that of their peripheral nerves.

Adolescent↗
PubMedDate not supplied

Human middle-latency auditory evoked potentials: vertex and temporal components.

We recorded middle-latency (20-70 msec) auditory evoked potentials (MLAEPs) to monaural and binaural clicks in 30 normal adults (ages 20-49 years) at 32 scalp locations all referred to a balanced non-cephalic reference. Our goal was to define the MLAEP components that were present at comparable latencies and comparable locations across the subject population. Group and individual data were evaluated both as topographic maps and as MLAEPs at selected electrode locations. Three major components occurred between 20 and 70 msec, two well-known peaks centered at the vertex, and one previously undefined peak focused over the posterior temporal area. Pa is a 29 msec positive peak centered at the vertex and present with both monaural and binaural stimulation. Pb is a 53 msec positive peak also centered at the vertex but seen consistently only with binaural and right ear stimulation. TP41 is a 41 msec positive peak focused over both temporal areas. TP41 has not been identified in previous MLAEP studies that concentrated on central scalp locations and/or used active reference electrode sites such as ears or mastoids. Available topographic, intracranial, pharmacologic, and lesion studies indicate that Pa, Pb and TP41 are of neural origin. Whether Pa and/or Pb are produced in Heschl's gyrus, primary auditory cortex, remains unclear. TP41 is probably produced by auditory cortex on the posterior lateral surface of the temporal lobe. It should prove of considerable value in experimental and clinical evaluation of higher level auditory function in particular and of cortical function in general.

Adult↗
PubMedDate not supplied

Psychoacoustic and electrophysiologic effects of partial eighth nerve damage.

The authors present psychoacoustic and electrophysiologic data concerning a patient with partial damage to the auditory nerve, presumably from a dilated arterial vessel. The lesion was described and documented during neurosurgery for vestibular nerve decompression. Pure tone thresholds, psychoacoustical tuning curves, speech reception ability for spondaic words, maximum word recognition performance for monosyllabic NU-6 word lists, and performance on the synthetic sentence identification test in the ipsilateral and contralateral competing message modalities were normal. Findings consistent with eighth nerve dysfunction, absent contralateral acoustic reflexes, absent or unrecognizable early evoked potentials occurring in the first 10 msec, brainstem auditory evoked potentials (BAEPs), and slight rollover of the performance intensity function for monosyllabic words were obtained on the involved side. In spite of the grossly abnormal BAEPs, two late, presumably cortical, auditory evoked potential components, which occur in the 60 to 250-msec range--vertex potential and T complex--were present and normal. The findings indicate that the perceptual processes needed for speech reception and recognition and for the appearance of later, presumably cortical-evoked potentials can be preserved despite partial damage to the auditory nerve.

Adult↗