Human Hemispheres Research Articles

Individual subjective preference of listeners for vocal music sources in relation to the subsequent reverberation time of sound fields

The purpose of this study is to evaluate subjective preference of a simulated sound field by listeners in changing subsequent reverberation time Tsub using vocal music sources. Previously, a great deal of effort has been made on the study using music or speech [for example, Ando et al., Acustica 50, 134–141 (1982); J. Acoust. Soc. Jpn. 39, 89–95 (1983)]. In addition to subjective preference judgments, the α-waves’ range of the continuous brain waves (CBW) in relation to the specialization of human cerebral hemispheres is also evaluated [C. Chen and Y. Ando, J. Archit. Plann. Environ. Eng., AIJ 489, 73–80 (1996)]. In this paper, subjective evaluation using vocal music sources, which is often played in concert halls and opera houses, has been examined. Subjective preference tests were conducted changing Tsub, which is one of the four objective parameters in relation to subjective preference of sound fields. Individual differences of subjective preference as well as global preference are discussed. [Work was partially supported by the Ministry of Education, Grant-in-Aid for Scientific Research (C), 9838022, 1997.]

New diagnostic system measuring orthogonal factors and calculating subjective attributes of sound fields in a real room

Based on the model of the auditory-brain system which consists of the autocorrelation mechanism, the interaural cross-correlation mechanism between the both auditory pathways, and the specialization of human cerebral hemispheres, a new diagnostic system was developed. The system works on a PC for Windows, thus there is no need for special additional devices. After obtaining the impulse response, four orthogonal factors including the SPL, the initial time delay gap between the direct sound and the first reflection, the subsequent reverberation time, and IACC are analyzed for the calculation of the scale values of global and individual subjective preference. In addition to the four factors, two more factors, τIACC and WIACC, in the interaural cross-correlation function are figured out for evaluating the image shift of the sound source and the apparent source width (ASW), respectively. Also, the effective duration, τe, and fine structures of autocorrelation function of sound signals including the value of first maximum, φ1, and its delay time τ1, are analyzed. Keeping the subjectively optimal condition, this system may be utilized for automatic control of sound fields by electroacoustic systems. The new system will be demonstrated at the presentation of this paper. [Work supported by the Ministry of Education, Grant-in-Aid for Scientific Research.]

Rags to Riches: Our Increasing Appreciation of Cognitive and Communicative Abilities of the Human Right Cerebral Hemisphere

Studies of right hemisphere abilities have grown from focusing on visuospatial and facial recognition in the 1950s to covering a broad spectrum of human behavior. The emergence of better understanding of auditory specializations, affective/emotional functions, personal relevance, idiosyncratic lexical organization, and the various aspects of language use—communicative pragmatics—is briefly reviewed.

Disproportion of cerebral surface areas and volumes in cerebral dysgenesis. MRI-based evidence for connectional abnormalities.

In the normal adult human brain, there are quantitative relationships between a surface area measure of the grey matter and the volume of hemispheric grey matter, the volume of the hemispheric subcortical matter and the cross-sectional area of the corpus callosum as revealed by analysis of high resolution MRI data. These relationships reflect structural order in, and biological features of, normal human cerebral hemispheres. Cerebral dysgenesis (CD) is associated with disruption of the normal organization of the hemispheres to a greater or lesser extent and is often manifest as refractory epilepsy. We have examined structural proportions and their disruption in the brains of patients with epilepsy and CD. We found that structural measures were abnormal in 60% of patients with CD, with abnormalities in 64% of hemispheres that, on visual inspection alone, appeared completely normal. We showed that the disruptions found are compatible with expected histopathology in cases where histopathology may be predictable, and that extensive abnormalities may be due to abnormal patterns of connections within the hemispheres. In some cases, it may be possible to predict histopathology on the basis of quantitative analyses of high resolution MRI data, when such prediction is not possible on visual inspection alone.

Topographical variation of the human primary cortices: implications for neuroimaging, brain mapping, and neurobiology.

The relationships of the "primary" cytoarchitectonic neocortical fields, 17, 41, 3b, and 4 (Brodmann areas), to salient topographic landmarks have been reconstructed from serial histological sections in 20 human cerebral hemispheres (10 brains). Each of these architectonic fields is found to bear a characteristic relationship to a set of enframing anatomic landmarks, in particular, gyri, fissures, and sulci, that can be readily defined by MRI. Two classes of variability were found characteristic, at least to some extent, of each of the fields. Class 1 variability--variability that is not predictable from visible landmarks--was typical of the polar and for the cuneal and lingual extracalcarine distributions of field 17 and the distribution of field 4 upon the paracentral lobule. Class 2 variability--variability that is closely predictable from visible landmarks--is seen in the marked interindividual or interhemispheric variation in size or shape of a field and was found to be prominent for all four fields. Because of the prominence of class 2 variability, direct reference to the landmarks that frame these fields may be expected to be a more reliable basis for functional mapping than reference to a template or stereotactic coordinate-based system of reference to a standard or idealized brain.

Neuronal architecture of the human temporal cortex

The cortex of the superior, middle and inferior temporal gyri of the human cerebral hemispheres was investigated using Nissl, Golgi and fibre staining techniques. Brodmann's (1909) area 41, corresponding to the primary auditory cortex in Heschl's transverse temporal gyri, consisted of typical koniocortex, and formed the middle part of the superior temporal plane (the buried lower bank of the Sylvian fissure). Anteriorly the superior temporal plane contained area 22, and posteriorly the planum temporale (part of area 42). The lateral surfaces of the superior, middle and inferior temporal gyri respectively correspond to areas 22, 21 and 20. Neurons in much of the left temporal cortex, apart from area 41, formed radial columns. This columnar organisation was most pronounced posteriorly and superiorly, so that anterior area 20 was the least columnar and area 42 the most. The right temporal cortex was markedly less columnar than the left. Golgi studies showed a variety of pyramidal and non-pyramidal neurons, with specific varieties typical of individual cortical layers.

The Cerebral Hemispheres and Bilateral Neural Nets

A high-level cognitive dichotomy ("language and context") is reviewed in relation to empirical findings concerning the functions of the human cerebral hemispheres. We argue that the right hemisphere's involvement in the generation of connotative and contextual information in parallel with the denotative and literal language functions of the left hemisphere provides an important insight into the organization of viable cognitive systems. The role of the corpus callosum in producing the dichotomy is discussed. Finally, the generation of asymmetrical activity in structurally symmetrical, bilateral neural nets is described. The model demonstrates how complementary memory states can be generated in bilateral nets without assuming different modes of information processing, provided that the nets have inhibitory, homotopic connections. Unlike excitatory connections, inhibitory connections are sufficient to generate asymmetric hemispheric activity without postulating intrinsic differences between the cerebral hemispheres.

Visualizations as Concrete Aids to Learning

Research Article| April 01 1989 Visualizations as Concrete Aids to Learning Carol A. Biermann Carol A. Biermann Search for other works by this author on: This Site PubMed Google Scholar The American Biology Teacher (1989) 51 (4): 234–236. https://doi.org/10.2307/4448910 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Carol A. Biermann; Visualizations as Concrete Aids to Learning. The American Biology Teacher 1 April 1989; 51 (4): 234–236. doi: https://doi.org/10.2307/4448910 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentThe American Biology Teacher Search This content is only available via PDF. Copyright 1989 National Association of Biology Teachers Article PDF first page preview Close Modal You do not currently have access to this content.

The inner universe: A multidisciplinary approach to the acoustics of concert halls

After introducing dimensional factors of the acoustic system in a concert hall, the capability of calculating acoustical quality at any seat based upon the theory of preference is presented. The effort to describe important qualities of sound in terms of the processes of the auditory pathways and brain has been brought to bear on the problem. If enough were known about how the auditory and the central nervous systems modify the nerve impulses from the cochlea, the design of concert halls could proceed according to guidelines derived from knowledge of these processes. An attempt to analyze this is made through study of the auditory‐evoked potentials over the left and right human cerebral hemispheres. In addition, results of recording the slow vertex responses (SVR), which were obtained by adjusting the temporal and spatial physical factors, indicated that the information related to subjective preference appeared in the latency components. The longest‐latency responses were observed at the most‐preferred condition or at the most subjectively diffuse condition. The correlation between brain activity and subjective preference seems to indicate that subjective preference can be traced back to a primitive response in the “inner universe.” Thus, such a theory with temporal and spatial factors may be generalized in designing physical environments for every human activity.

Human cerebral hemispheres develop at different rates and ages.

The development of the cerebral hemispheres was assessed by using measures of electroencephalographic coherence and phase in 577 children ranging in age from 2 months to early adulthood. Two categories of age-dependent change in electroencephalographic coherence and phase were noted: continuous growth processes that were described best by an exponential growth function, and discrete growth spurts that appeared in specific anatomical locations at specific postnatal periods. The left and right hemispheres developed at different rates and with different postnatal onset times with the timing of growth spurts overlapping the timing of the major developmental stages described by Piaget.

CT identification of cortical speech areas in the human brain.

In four human left cerebral hemispheres the cortical speech areas were identified, having been marked by differential color code before transverse sectioning. The results from the anatomic dissection specimens were compared with thin CT sections in normal individuals, the CT plane being aligned to the orbitomeatal plane as an external reference, and thus closely parallel to the bicommissural plane, as an internal reference. The same cortical structures were identified in the CT sections. A strategic approach to CT examination of the cortical speech areas is formulated, based on the external-internal system of reference.

Lateralization of functions in the vertebrate brain: a review.

That the human left and right cerebral hemispheres perform different functions is widely accepted; but there is little evidence of whether or not similar functional asymmetries exist in non-human vertebrates. In this paper, neuro-anatomical similarities between human and other vertebrate brains are considered, and data concerning physical asymmetries reviewed. The defining features of human lateralization are taken to be right-handedness, as a skewed but continuous distribution of preferences, and a greater involvement of the left hemisphere in species-specific vocalization, with right-hemisphere superiority in spatial perception and emotionality less well-marked characteristics. Rodents, cats, at least one species of marsupial, and macaque monkeys have consistent hand preferences for food reaching. These may result from constitutional factors, but in every species studied the distribution of preferences is unskewed. Canaries appear to have left-hemisphere dominance of vocal production, and there is limited support for the conjecture that macaque monkeys have left-hemisphere dominance for reception of species-specific cries, and/or for short-term auditory memory. Left and right unilateral hemispheric damage may have appreciably different effects on emotionality in rats, sound localization in cats, and tactile discrimination in monkeys, although the available evidence is equivocal. It seems possible that asymmetries of cerebral function are widespread in vertebrates. In particular, left hemisphere dominance of species-specific communication might be common in birds and primates: left-hemisphere dominance of human speech may be an example of a general vertebrate tendency towards unilateral control of vocalization.

Differences in the distribution of gray and white matter in human cerebral hemispheres.

The distribution of gray matter in the two cerebral hemispheres was determined by the xenon-133 inhalation method. There was more gray matter relative to white matter in the left hemisphere than in the right, particularly in the frontal and precentral regions. This finding suggests that the organization of the left hemisphere, relative to that of the right, emphasizes processing or transfer within regions, or both, rather than transfer across regions.

Cerebral dominance for conspecific sound perception in monkeys?

Convergent evidence from electrophysiological, anatomical, and behavioral studies suggests a preeminent role for specific regions of the human left cerebral hemisphere in both the production and perception of speech sounds. The present study aimed to determine whether nonhuman primates show a similar lateralization of function when performing perceptual tasks requiring the analysis of species-specific vocalizations. Five Japanese macaques (Macaca fuscata) and five other Old World monkeys were trained, using operant conditioning techniques, to discriminate between different classes of acoustic stimuli. In one experiment, all animals were required to discriminate between two classes of Japanese macaque vocalizations by attending to a communicatively significant acoustic cue. In a second experiment, the animals were forced to attend to an orthogonal acoustic feature of the same vocalizations. In both experiments, stimuli were delivered monaurally to either the left or right ear according to a random schedule. All five Japanese macaques but only one of the comparison animals showed a right-ear performance advantage, suggesting left hemisphere dominance, when analyzing the communicatively significant feature of the vocalizations. Neither the Japanese or comparison animals showed a right-ear advantage when processing the orthogonal pitch feature. The results directly parallel studies of human speech lateralization which report a right-ear advantage for the processing of linguistically relevant acoustic cues but not for the perception of paralinguistic cues. Therefore, our findings suggest a potential analogy between the functionally lateralized mechanisms used in human speech and those apparently engaged by the Japanese macaques for the analysis of conspecific sounds. [Work supported by NSF, NIH and NIMH.]

Intraluminal diameters of middle cerebral branches for microanastomoses.

Intraluminal diameter measurements of the branches of the middle cerebral artery were taken from 50 adult human cerebral hemispheres of a routine autopsy service. The measurements were confined to the cortical branches found on the surface of the brain located over the lateral hemisphere, with the center at the transverse gyrus of Heschl and extending over the circular portion of the brain, with a diameter of approximation 6 cm. It was hoped that these measurements would assist in the appropriate choice of artery for microanastomosis in the superficial temporal artery bypass procedure, now being done for enhancement of cortical perfusion.

Functional cerebral asymmetry and performance. III. Reaction time as a function of task, hand, sex, and EEG asymmetry.

ABSTRACTTo determine whether fluctuations of EEG asymmetry in the human cerebral hemispheres influenced overt performance, 14 male and 14 female subjects were tested in verbal and nonverbal target detection tasks and reaction time (RT) was recorded. RT was longest in both word and pattern tasks when the hand used for responding was contralateral to the hemisphere presumably most relevant to the task. The task variable did not affect EEG asymmetry, but females had lower R/L alpha ratios than males and EEG power increased and frequency decreased over the course of testing in association with decreased RT. RT also varied as a function of EEG asymmetry. In contrast to original expectations, RT was longest to verbal targets when R/L alpha power ratios were highest and longest to nonverbal targets when R/L ratios were lowest. The results were compatible with the notion of an inverted U function relating performance and arousal, and supported previous studies indicating that alpha asymmetry influences overt performance.

In vivo localization of brain sulci by arteriography: a stereotactic anatomoradiological study

The authors studied the course of the cortical arteries using the Talairach stereotactic system (orthogonal 4.8 m teleradiography, with rigid fixation of the skull in the stereotactic frame) in both anatomical specimens and normal bilateral carotid angiographies of epileptic patients. Anatomoradiological correlations between arterial patterns and underlying brain surface were identified by detailed 3-dimensional analysis of brain-skull preparations, where gyri and injected arteries were dissected progressively with stereotactic X-ray and photographic pictures taken at each step. The vascular landmarks so identified were studied in stereoscopic arteriographies that give a direct visualization of the spatial relationships of the arterial tree moulding the cortical surface thus allowing the recognition of the localization of the principal gyri and sulci. The latter were drawn on stereotactic diagrams. The basic sulcal pattern as shown by the arteries is strikingly symmetrical in both hemispheres of the same individual, in spite of variability in branching of the arterial tree. The disposition of the vascular landmarks in the retroinsular region reflects the left-right asymmetry of the planum temporale that can be recognized in vivo. This can give a clue to the study of anatomofunctional correlations with regard to speech dominance. A limited first series studied in this respect strongly suggests a close relationship between anatomical and functional asymmetry of the human cerebral hemispheres. Generally speaking, the authors feel that 3- dimensional, anatomical interpretation of angiography permits a direct localization of brain structures including the cortex, that can be used instead of indirect localization landmarks in stereotactic explorations, and further, that the wealth of anatomical information that can be drawn from angiography with their method may be helpful in diagnosis or for planning surgery.

Determination of calcium, copper, magnesium, and zinc content of identical areas in human cerebral hemispheres of normals

The distribution of calcium, copper, magnesium and zinc in five anatomical regions of both hemispheres of the human brain were investigated. No asymmetry was observed with the exception of the distribution of copper in the white matter. The concentrations of these elements in the substantia nigra from both sides of the midbrain were also measured.

Improvements of plasma spraying processes for hybrid microelectronics : M. Braguier, J. Bejat, R. Tueta, M. Verna, G. Aubin and C. Naturel. IERE Conf. Hybrid Microelectron. Canterbury. 15 (25–27 Sept. 1973)

Previous studies demonstrated substantial variability of the location of primary visual cortex (V1) in stereotaxic coordinates when linear volume-based registration is used to match volumetric image intensities [Amunts, K., Malikovic, A., Mohlberg, H., Schormann, T., and Zilles, K. (2000). Brodmann’s areas 17 and 18 brought into stereotaxic space—where and how variable? Neuroimage, 11(1):66–84]. However, other qualitative reports of V1 location [Smith, G. (1904). The morphology of the occipital region of the cerebral hemisphere in man and the apes. Anatomischer Anzeiger, 24:436–451; Stensaas, S.S., Eddington, D.K., and Dobelle, W.H. (1974). The topography and variability of the primary visual cortex in man. J Neurosurg, 40(6):747–755; Rademacher, J., Caviness, V.S., Steinmetz, H., and Galaburda, A.M. (1993). Topographical variation of the human primary cortices: implications for neuroimaging, brain mapping, and neurobiology. Cereb Cortex, 3(4):313–329] suggested a consistent relationship between V1 and the surrounding cortical folds. Here, the relationship between folds and the location of V1 is quantified using surface-based analysis to generate a probabilistic atlas of human V1. High-resolution (about 200 μm) magnetic resonance imaging (MRI) at 7 T of ex vivo human cerebral hemispheres allowed identification of the full area via the stria of Gennari: a myeloarchitectonic feature specific to V1. Separate, whole-brain scans were acquired using MRI at 1.5 T to allow segmentation and mesh reconstruction of the cortical gray matter. For each individual, V1 was manually identified in the high-resolution volume and projected onto the cortical surface. Surface-based intersubject registration [Fischl, B., Sereno, M.I., Tootell, R.B., and Dale, A.M. (1999b). High-resolution intersubject averaging and a coordinate system for the cortical surface. Hum Brain Mapp, 8(4):272–84] was performed to align the primary cortical folds of individual hemispheres to those of a reference template representing the average folding pattern. An atlas of V1 location was constructed by computing the probability of V1 inclusion for each cortical location in the template space. This probabilistic atlas of V1 exhibits low prediction error compared to previous V1 probabilistic atlases built in volumetric coordinates. The increased predictability observed under surface-based registration suggests that the location of V1 is more accurately predicted by the cortical folds than by the shape of the brain embedded in the volume of the skull. In addition, the high quality of this atlas provides direct evidence that surface-based intersubject registration methods are superior to volume-based methods at superimposing functional areas of cortex and therefore are better suited to support multisubject averaging for functional imaging experiments targeting the cerebral cortex.

Regional Cerebral Blood Flow in Man: Establishment of “Normal” Control Values and Identification of the Abnormalities which Occur in “Stroke” Patients

The human cerebral hemisphere consists of two very distinct types of tissue, grey matter, and white matter, which are perfused with blood at markedly different rates. To collect good regional data regarding blood flow in different parts of the cerebral hemisphere, it is necessary to use multiple detectors that are specifically designed to minimize the amount of overlap among adjacent detector fields. Grey matter perfusion is not homogeneous throughout the normal hemisphere in conscious patients or in patients anaesthetized by nitrous oxide and oxygen supplemented by neuroleptanalgesia (droperidol and phenoperidine). Grey matter perfusion is relatively homogeneous throughout the normal cerebral hemisphere in patients anaesthetised by the same technique, but studied during conditions of arterial hypocapnia. White matter perfusion is not homogeneous throughout the normal cerebral hemisphere. The ratio of the weight of perfused grey matter to perfused white matter is by no means constant throughout the hemisphere. The relative weight of grey matter is high in the insular region, low over the corpus callosum and corona radiata, and intermediate or high over the convexity of the hemisphere. Evidence is accumulating to confirm that two-compartmental analysis of regional 133 Xenon clearance curves provides a valid and detailed picture of the state of disordered perfusion that occurs in patients who have suffered various types of stroke.