Human complex sound analysis*

1999 ◽  
Vol 96 (3) ◽  
pp. 231-234 ◽  
Author(s):  
T. D. GRIFFITHS
Keyword(s):  
Auditory System ◽  
Functional Imaging ◽  
Language Impairment ◽  
Specific Language Impairment ◽  
Parietal Lobe ◽  
Primary Auditory Cortex ◽  
Normal Subjects ◽  
Complex Sound ◽  
Positron Emission ◽  
The Right

The analysis of complex sound features is important for the perception of environmental sounds, speech and music, and may be abnormal in disorders such as specific language impairment in children, and in common adult lesions including stroke and multiple sclerosis. This work addresses the problem of how the human auditory system detects features in complex sound, and uses those features to perceive the auditory world. The work has been carried out using two independent means of testing the same hypotheses; detailed psychophysical studies of neurological patients with central lesions, and functional imaging using positron emission tomography and functional magnetic resonance imaging of normal subjects. The psychophysical and imaging studies have both examined which brain areas are concerned with the analysis of auditory space, and which are concerned with the analysis of timing information in the auditory system. This differs from many previous human auditory studies, which have concentrated on the analysis of sound frequency. The combined lesion and functional imaging approach has demonstrated analysis of the spatial property of sound movement within the right parietal lobe. The timing work has confirmed that the primary auditory cortex is active as a function of the time structure of sound, and therefore not only concerned with frequency representation of sounds.

Dynamic Temporal Processing of Nonspeech Acoustic Information by Children With Specific Language Impairment

1996 ◽  
Vol 39 (3) ◽  
pp. 510-517 ◽  
Author(s):  
Jane C. Visto ◽  
Jerry L. Cranford ◽  
Rosalind Scudder
Keyword(s):  
Language Learning ◽  
Language Impairment ◽  
Specific Language Impairment ◽  
Precedence Effect ◽  
Complex Sound ◽  
Specific Language ◽  
Acoustic Information ◽  
Rapid Changes ◽  
Spectral Components ◽  
Normal Language

The present study investigated whether children with specific language impairment (SLI) differed from children with normal language learning in their ability to process binaural temporal information. The SLI group was matched with peers of the same chronological age, as well as peers with similar language age. All three subject groups were tested with measures of complex sound localization involving the precedence effect phenomenon. Subjects were required to track the apparent motion of a “moving” fused auditory image (FAI). Movement of the FAI was simulated by varying the delay incrementally between pairs of clicks presented, one each, from two matched loudspeakers placed on opposite sides of the child’s head. With this task, the SLI subjects’ performances were found to be similar to their language age-matched but chronologically younger peers. Both groups exhibited tracking skills that were statistically poorer than that of the chronologically age-matched group. Additional tests indicated this effect was not due to differences in motoric tracking abilities nor to the SLI subjects’ abilities to perceive small binaural time cues. Thus, children with SLI appear to be impaired in their ability to use binaural acoustic information in a dynamic ongoing fashion. The requirements for processing such nonlinguistic acoustic information in a “dynamic and ongoing” fashion may be similar to those involved in the ongoing processing of rapid changes in the temporal and spectral components of the speech chain.

Brain Morphology in Children With Specific Language Impairment

1997 ◽  
Vol 40 (6) ◽  
pp. 1272-1284 ◽  
Author(s):  
Laurie M. Gauger ◽  
Linda J. Lombardino ◽  
Christiana M. Leonard
Keyword(s):  
Left Hemisphere ◽  
Language Impairment ◽  
Specific Language Impairment ◽  
Language Skills ◽  
Brain Morphology ◽  
Planum Temporale ◽  
Specific Language ◽  
Normal Language ◽  
Pars Triangularis ◽  
The Right

The planum temporale and pars triangularis have been found to be larger in the left hemisphere than the right in individuals with normal language skills. Brain morphology studies of individuals with developmental language disorders report reversed asymmetry or symmetry of the planum, although the bulk of this research has been completed on adults with dyslexia. Pars triangularis has not been studied in the developmental language impaired population. In this study, magnetic resonance imaging (MRI) was used for quantitative comparisons of the planum temporale (Wernicke’s area) and pars triangularis (Broca’s area) in children with specific language impairment (SLI) and children with normal language skills. The subjects were 11 children with SLI and 19 age- and sex-matched controls between 5.6 and 13.0 years old. Each subject received a neurolinguistic battery of tests and a high resolution volumetric MRI scan. Major results were that (a) pars triangularis was significantly smaller in the left hemisphere of children with SLI, and (b) children with SLI were more likely to have rightward asymmetry of language structures. Furthermore, anomalous morphology in these language areas correlated with depressed language ability. These findings support the hypothesis that language impairment is a consequence of an underlying neurobiological defect in areas of the brain known to subserve language.

Quantification of regional V/Q ratios in humans by use of PET. II. Procedure and normal values

1989 ◽  
Vol 66 (4) ◽  
pp. 1905-1913 ◽  
Author(s):  
C. G. Rhodes ◽  
S. O. Valind ◽  
L. H. Brudin ◽  
P. E. Wollmer ◽  
T. Jones ◽  
...  
Keyword(s):  
Left Lung ◽  
Normal Subjects ◽  
Slice Thickness ◽  
Dependent Lung ◽  
Quiet Breathing ◽  
Mean Values ◽  
Positron Emission ◽  
Supine Posture ◽  
Quantitative Manner ◽  
The Right

Regional measurements of tissue isotope concentration, made using positron emission tomography (PET), allow tracer models to be used in a quantitative manner to provide topographic distributions of many structural and functional parameters, each derived for the same well-defined lung element. In this paper we describe a technique to measure regional ventilation-perfusion ratios (V/Q), in absolute units, by use of PET and the continuous intravenous infusion of an inert gas isotope, 13N, and report on measurements made in 12 normal subjects (4 smokers). Data were obtained from a single lung section (slice thickness, 1.7 cm full width at half-maximum response to a line source) at the level of the right ventricle in the supine posture during quiet breathing. For the 12 subjects, volume-weighted mean values of V/Q, averaged over individual right and left lung fields, ranged from 0.50 to 1.29. Analysis of these means showed no difference between lungs: right, 0.80 +/- 0.23 SD; left, 0.76 +/- 0.20 SD. Topographically, a systematic fall of V/Q in the ventrodorsal direction was observed in eight of the subjects (mean ventrodorsal difference 0.39, range 0.19–0.90), whereas two showed a clear increase toward dependent lung regions (range 0.16–0.26). Seven of the subjects with a falling ventrodorsal V/Q gradient also exhibited discrete regions of low V/Q at the dorsal lung border. We conclude that, in normal subjects, ventilation and perfusion are generally well matched in the supine posture, but isolated mismatching often occurs in dependent lung regions.

Knowing Where Things Are: Parahippocampal Involvement in Encoding Object Locations in Virtual Large-Scale Space

1998 ◽  
Vol 10 (1) ◽  
pp. 61-76 ◽  
Author(s):  
E. A. Maguire ◽  
C. D. Frith ◽  
N. Burgess ◽  
J. G. Donnett ◽  
J. O'Keefe
Keyword(s):  
Medial Temporal Lobe ◽  
Large Scale ◽  
Critical Factor ◽  
Normal Subjects ◽  
Scale Space ◽  
Parahippocampal Gyrus ◽  
Environmental Learning ◽  
Object Locations ◽  
Positron Emission ◽  
The Right

The involvement of the medial temporal-lobe region in allocentric mapping of the environment has been observed in human lesion and functional imaging work. Cognitive models of environmental learning ascribe a key role to salient landmarks in representing large-scale space. In the present experiments we examined the neural substrates of the topographical memory acquisition process when environmental landmarks were more specifically identifiable. Using positron emission tomography (PET), we measured regional cerebral blood flow changes while normal subjects explored and learned in a virtual reality environment. One experiment involved an environment containing salient objects and textures that could be used to discriminate different rooms. Another experiment involved a plain empty environment in which rooms were distinguishable only by their shape. Learning in both cases activated a network of bilateral occipital, medial parietal, and occipito-temporal regions. The presence of salient objects and textures in an environment additionally resulted in increased activity in the right parahippocampal gyrus. This region was not activated during exploration of the empty environment. These findings suggest that encoding of salient objects into a representation of large-scale space is a critical factor in instigating parahippocampal involvement in topographical memory formation in humans and accords with previous studies implicating parahippocampal areas in the encoding of object location.

Functional Anatomy of Perceptual and Semantic Processing for Odors

1999 ◽  
Vol 11 (1) ◽  
pp. 94-109 ◽  
Author(s):  
Jean-P. Royet ◽  
Olivier Koenig ◽  
Marie-C. Gregoire ◽  
Luc Cinotti ◽  
Frank Lavenne ◽  
...  
Keyword(s):  
Semantic Processing ◽  
Inferior Frontal Gyrus ◽  
Functional Anatomy ◽  
Normal Subjects ◽  
Anterior Cingulate ◽  
Perceptual Condition ◽  
Semantic Level ◽  
Positron Emission ◽  
Visual Areas ◽  
The Right

The functional anatomy of perceptual and semantic processings for odors was studied using positron emission tomography (PET). The first experiment was a pretest in which 71 normal subjects were asked to rate 185 odorants in terms of intensity, familiarity, hedonicity, and comestibility and to name the odorants. This pretest was necessary to select the most appropriate stimuli for the different cognitive tasks of the second experiment. The second one was a PET experiment in which 15 normal subjects were scanned using the water bolus method to measure regional cerebral blood flow (rCBF) during the performance in three conditions. In the first (perceptual) condition, subjects were asked to judge whether an odor was familiar or not. In the second (semantic) condition, subjects had to decide whether an odor corresponded to a comestible item or not. In the third (detection) condition, subjects had to judge whether the perceived stimulus was made of an odor or was just air. It was hypothetized that the three tasks were hierarchically organized from a superficial detection level to a deep semantic level. Odorants were presented with an air-flow olfactometer, which allowed the stimulations to be synchronized with breathing. Subtraction of activation images obtained between familiarity and control judgments revealed that familiarity judgments were mainly associated with the activity of the right orbito-frontal area, the subcallosal gyrus, the left inferior frontal gyrus, the left superior frontal gyrus, and the anterior cingulate (Brodmann's areas 11, 25, 47, 9, and 32, respectively). The comestibility minus familiarity comparison showed that comestibility judgments selectively activated the primary visual areas. In contrast, a decrease in rCBF was observed in these same visual areas for familiarity judgments and in the orbitofrontal area for comestibility judgments. These results suggest that orbito-frontal and visual regions interact in odor processing in a complementary way, depending on the task requirements.

Blood Supply of Primary Auditory Cortex in Chinchilla: A Corrosion Cast Study

2000 ◽  
Vol 6 (S2) ◽  
pp. 570-571
Author(s):  
R.J. Mount ◽  
R.V. Harrison ◽  
N. Harel ◽  
J. Panesar ◽  
H. Hamrahi
Keyword(s):  
Auditory Cortex ◽  
Optical Imaging ◽  
Functional Imaging ◽  
Imaging Techniques ◽  
Primary Auditory Cortex ◽  
Control Mechanisms ◽  
Cerebral Vasculature ◽  
Intrinsic Signals ◽  
Corrosion Cast ◽  
The Right

INTRODUCTION: The chinchilla animal model is widely used to study the function of the auditory system. The location of auditory cortex in the chinchilla has previously been determined both electrophysiologically and by optical imaging of intrinsic signals. The spatial resolution of functional imaging techniques which rely on changes in the BOLD (blood oxygen dependent level) signal to create images of activity (i.e., fMRI and optical imaging) are ultimately dependent on the resolution of microcirulatory control mechanisms. For example, in response to pure tone auditory stimuli, functional resolution (within cortex) of approximately 400 um has been demonstrated using optical imaging. To better understand the limits of functional imaging the present study was undertaken to explore the structure and properties of the arterial supply within auditory cortex.METHODS: Plastic casts of the cerebral vasculature were prepared by cannulating the ascending aorta, incising the right atrium and then perfusing 50 ml heparinized PBS followed by 20 ml of Batson's #17 resin.

A Review of Functional Neuroimaging in Mood Disorders: Positron Emission Tomography and Depression

1997 ◽  
Vol 42 (5) ◽  
pp. 467-475 ◽  
Author(s):  
Sidney H Kennedy ◽  
Mahan Javanmard ◽  
Franco J Vaccarino
Keyword(s):  
Positron Emission Tomography ◽  
Mood Disorders ◽  
Functional Imaging ◽  
Functional Neuroimaging ◽  
Imaging Techniques ◽  
Normal Subjects ◽  
Emission Tomography ◽  
Psychiatric Research ◽  
Positron Emission ◽  
Activation Conditions

Objective: To examine the progress of positron emission tomography (PET) as a tool for understanding the psychobiology of mood disorders, particularly major depression and bipolar disorder. Method: Review of the literature on functional imaging of mood disorders. Results: Functional imaging techniques have been used in psychiatric research as a noninvasive method to study the behaviour and function of the brain. Techniques used so far have involved the manipulation of emotion in healthy volunteers, the evaluation of depressed (unipolar and bipolar as well as secondary depression), manic, and normal subjects under resting and various activation conditions, such as cognitive activation, acute pharmacological challenge, and chronic thymoleptic treatments. As a result, functional imaging studies tend to support abnormalities in specific frontal and limbic regions. Conclusion: Different PET methods demonstrate consistent abnormalities in the prefrontal, cingulate, and amygdala regions. These findings are in agreement with past animal and clinical anatomical correlates of mood and emotions.

Markedness in Right-edge Syllabification: Parallels across Populations

2002 ◽  
Vol 47 (3-4) ◽  
pp. 151-186 ◽  
Author(s):  
Heather Goad
Keyword(s):  
Second Language ◽  
Empirical Evidence ◽  
Language Learners ◽  
Language Impairment ◽  
Specific Language Impairment ◽  
Second Language Learners ◽  
Emergent Property ◽  
Specific Language ◽  
The Right

AbstractThe position that languages require both coda and onset options for the syllabification of word-final consonants is adopted. The latter option is further divided into languages where final consonants are onsets of empty-headed syllables and those where final consonants are syllabified through onset-nuclear (ON) sharing. ON sharing is reserved for languages where final consonants display fortition (overt release): the nucleus hosts the release of the consonant. Empirical evidence from across populations demonstrates that ON sharing is unmarked. It is favoured among the outputs of first and second language learners and individuals with Specific Language Impairment. It is further argued that final onsets are optimal for parsing in end-state grammars, as they demarcate the right word-edge more effectively than codas. Among the two types of onsets, ON sharing is preferred: through the nuclear release, it is better able to host the range of contrasts that right-edge onsets display. The parsing argument serves to illustrate how ON sharing provides an advantage to end-state grammars, beyond being an emergent property from acquisition.

Prosodic Markers of Syntactic Boundaries in the Speech of 4-Year-Old Children With Normal and Disordered Language Development

1998 ◽  
Vol 41 (5) ◽  
pp. 1158-1170 ◽  
Author(s):  
David Snow
Keyword(s):  
Language Development ◽  
Language Impairment ◽  
Specific Language Impairment ◽  
Developmental Disorders ◽  
Syntactic Structure ◽  
Major Constituent ◽  
Morphosyntactic Development ◽  
Prosodic Boundary ◽  
Final Syllable ◽  
The Right

This study focuses on the potential role of prosodic "boundary features" in developmental disorders of morphosyntax. As exemplified melodically by the final portion of the falling tone and rhythmically by final syllable lengthening, boundary features mark the right edge of major constituent units in speech and thus phonetically reflect syntactic structure on the level of clauses and sentences. To resolve conflicting findings about the development of boundary features in children with specific language impairment (SLI), this study describes the falling tone and final syllable lengthening in the spontaneous speech of 10 four-year-old children with the phonologic-syntactic type of SLI and 10 four-year-old children with normal language development. The results—indicating that some prosodic boundary features are normal in preschoolers with SLI—show that impairments of morphology and syntax on the segmental level of the grammar do not implicate systematic deficits in syntax-sensitive features on the suprasegmental level. The potential dissociation between prosodic and morphosyntactic development is shown most clearly by the remarkable robustness of the falling tone, which was observed in 9 of the 10 children with SLI, in spite of the moderate to severe deficits they demonstrated in segmental phonology, morphosyntax, and mean length of utterance.

Activation of the Right Inferior Frontal Cortex During Assessment of Facial Emotion

1999 ◽  
Vol 82 (3) ◽  
pp. 1610-1614 ◽  
Author(s):  
Katsuki Nakamura ◽  
Ryuta Kawashima ◽  
Kengo Ito ◽  
Motoaki Sugiura ◽  
Takashi Kato ◽  
...  
Keyword(s):  
Frontal Cortex ◽  
Normal Subjects ◽  
Brain Regions ◽  
Facial Emotion ◽  
Facial Stimuli ◽  
Inferior Frontal Cortex ◽  
Positron Emission ◽  
Triangular Area ◽  
The Right ◽  
Communicative Signals

We measured regional cerebral blood flow (rCBF) using positron emission tomography (PET) to determine which brain regions are involved in the assessment of facial emotion. We asked right-handed normal subjects to assess the signalers’ emotional state based on facial gestures and to assess the facial attractiveness, as well as to discriminate the background color of the facial stimuli, and compared the activity produced by each condition. The right inferior frontal cortex showed significant activation during the assessment of facial emotion in comparison with the other two tests. The activated area was located within a triangular area of the inferior frontal cortex in the right cerebral hemisphere. These results, together with those of previous imaging and clinical studies, suggest that the right inferior frontal cortex processes emotional communicative signals that could be visual or auditory and that there is a hemispheric asymmetry in the inferior frontal cortex in relation to the processing of emotional communicative signals.

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