Judith L. Lauter

Bio: Judith L. Lauter is an academic researcher from University of Arizona. The author has contributed to research in topics: Dichotic listening & Auditory cortex. The author has an hindex of 8, co-authored 37 publications receiving 512 citations. Previous affiliations of Judith L. Lauter include University of Oklahoma & Central Institute for the Deaf.

Dichotic identification of complex sounds: absolute and relative ear advantages.

Abstract: Dichotic identification of a variety of complex sounds was studied in seven listeners. Analysis of individual listeners’ scores shows that there are significant individual differences in terms of absolute ear advantage for a given sound, while comparison of such differences across stimuli reveals agreements among individuals as to relative ear advantages, when both magnitude and direction of ear difference are considered. This agreement can be expressed in terms of a ’’relative ear advantage continuum.’’ The experiments also indicated that ear advantages can show good reliability over as much as six months’ time.

Stimulus characteristics and relative ear advantages: A new look at old data

Abstract: A recent report of a series of dichotic listening experiments [Lauter, J. Acoust. Soc. Am. 71, 701–707 (1982)] showed that although individual listeners differ in the ‘‘absolute ear advantage’’ shown for a given sound, there are patterns of ‘‘relative ear advantages’’ that are consistent across listeners. It was suggested that these patterns might provide a means of studying which features of test sounds are important in determining ear advantages. A survey of 12 earlier experiments, including a brief synopsis of procedures, results, and conclusions, followed by reanalysis of individual scores, shows that patterns of relative ear advantages were also present in earlier results, though obscured by an analysis that focused on the average listener. Examination of these patterns and the characteristics of sounds tested reveals a few acoustical features of sounds (e.g., event timing, bandwidth, number of dimensions changing with time) that seem to affect ear differences in a consistent way, from listener to li...

Individual Differences in Auditory Electric Responses: Comparisons of Between-Subject and Within-Subject Variability. V. Amplitude-variability Comparisons in Early, Middle, and Late Responses

Abstract: In this series of reports to date (Lauter & Loomis, 1986, 1988; Lauter & Karzon, 1990 a & b) we have described patterns of relative variability observed in latency and amplitude of auditory brainstem responses (ABRs) collected in a repeated-measures within-subjects design testing two groups of neurologically normal adults. Each of the two groups of subjects was additionally tested for one other type of auditory evoked potential, according to the same schedule of eight weekly sessions: middle-latency responses (MLRs: 10 to 50 ms post-stimulus) were collected from Group II (four females and four males), and late responses (50 to 300 ms post-stimulus) from Group I (four females and three males). This paper presents data comparing and contrasting the patterns of relative variability of waveform-peak latency observed in middle-latency, late responses, and the ABR data previously reported. Results document a trimodal distribution of response latency variability, with ABR peak V in one category, characterized by high within-subject stability and low between-subject stability, ABR peaks II, III, and IV, together with MLR peak No in a second category, of intermediate within-subject stability, and a third category consisting of ABR peak I together with all auditory-evoked-potential (AEP) peaks subsequent to MLR peak No, in which consistency of peak latency calculated within subjects approaches the low level of consistency calculated across subjects.

Latency stability of auditory brainstem responses in children aged 10-12 years compared with younger children and adults.

Abstract: Previous articles have reported the results of using standard clinical procedures in our laboratory for testing auditory brainstem responses (ABR) in a repeated-measures design, in order to quantify ABR latency and amplitude stability in normal young adults. In a subsequent paper, these findings were extended to include the results of similar procedures in a group of seven children ranging in age from 5 to 7 years. The current experiment involves repeated-measures ABRs in a group of nine children ranging in age from 10 to 12 years. Results indicate that while these older children show the expected similarities with adults in terms of ABR peak latencies, their latency stability values are in some cases significantly lower than adults. At the same time, ABR stabilities measured in the older children show some differences compared to data from the younger children studied previously. For all groups, the same types of patterns are observed: (1) significant differences contrasting the degree of between-subject v. within-subject latency stability; (2) clear individual differences characterizing subjects; (3) within-subject distinctions according to ear of stimulation; and (4) instances of good replicability of the 'latency-stability profiles' calculated for one set of repeated waveforms v. a second set collected later in testing.

The N1 wave of the human electric and magnetic response to sound: a review and an analysis of the component structure

Abstract: This paper reviews the literature on the Nl wave of the human auditory evoked potential. It concludes that at least six different cerebral processes can contribute to (he negative wave recorded from the scalp with a peak latency between 50 and 150 ms: a component generated in the auditory-cortex on the supratemporal plane, a component generated in the association cortex on the lateral aspect of the temporal and parietal cortex, a component generated in the motor and premotor cortices, the mismatch negativity, a temporal component of the processing negativity, and a frontal component of the processing negativity, The first three, which can be considered ‘true’ N1 components, are controlled by the physical and temporal aspects of the stimulus and by the general state of the subject. The other three components are not necessarily elicited by a stimulus but depend on the conditions in which the stimulus occurs. They often last much longer than the true N1 components that they overlap.

Positron emission tomographic studies of the cortical anatomy of single-word processing

Abstract: The use of positron emission tomography to measure regional changes in average blood flow during processing of individual auditory and visual words provides support for multiple, parallel routes between localized sensory-specific, phonological, articulatory and semantic-coding areas.

Lateralization of phonetic and pitch discrimination in speech processing

Abstract: Cerebral activation was measured with positron emission tomography in ten human volunteers. The primary auditory cortex showed increased activity in response to noise bursts, whereas acoustically matched speech syllables activated secondary auditory cortices bilaterally. Instructions to make judgments about different attributes of the same speech signal resulted in activation of specific lateralized neural systems. Discrimination of phonetic structure led to increased activity in part of Broca's area of the left hemisphere, suggesting a role for articulatory recoding in phonetic perception. Processing changes in pitch produced activation of the right prefrontal cortex, consistent with the importance of right-hemisphere mechanisms in pitch perception.

Positron emission tomographic studies of the processing of singe words

Abstract: PET images of blood flow change that were averaged across individuals were used to identify brain areas related to lexical (single-word) processing, A small number of discrete areas were activated during several task conditions including: modality-specific (auditory or visual) areas activated by passive word input, primary motor and premotor areas during speech output, and yet further areas during tasks making semantic or intentional demands.

"Sparse" temporal sampling in auditory fMRI.

Abstract: The use of functional magnetic resonance imaging (fMRI) to explore central auditory function may be compromised by the intense bursts of stray acoustic noise produced by the scanner whenever the magnetic resonance signal is read out. We present results evaluating the use of one method to reduce the effect of the scanner noise: "sparse" temporal sampling. Using this technique, single volumes of brain images are acquired at the end of stimulus and baseline conditions. To optimize detection of the activation, images are taken near to the maxima and minima of the hemodynamic response during the experimental cycle. Thus, the effective auditory stimulus for the activation is not masked by the scanner noise. In experiment 1, the course of the hemodynamic response to auditory stimulation was mapped during continuous task performance. The mean peak of the response was at 10.5 sec after stimulus onset, with little further change until stimulus offset. In experiment 2, sparse imaging was used to acquire activation images. Despite the fewer samples with sparse imaging, this method successfully delimited broadly the same regions of activation as conventional continuous imaging. However, the mean percentage MR signal change within the region of interest was greater using sparse imaging. Auditory experiments that use continuous imaging methods may measure activation that is a result of an interaction between the stimulus and task factors (e.g., attentive effort) induced by the intense background noise. We suggest that sparse imaging is advantageous in auditory experiments as it ensures that the obtained activation depends on the stimulus alone.