bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brain energy metabolism and the physiological basis of the haemodynamic response
Authors: Gjedde Albert 
Published: April 2012

Abstract. This chapter emphasizes the general principles of brain metabolism and the haemodynamic response to neuronal activity. The precise mechanisms responsible for the links between brain energy metabolism and brain work are not well defined. The chapter gives a detailed description of the nature of the metabolic work for information transfer in the brain, which provides an understanding of the link between changes in energy metabolism affecting physiological parameters such as blood flow and neuronal activity. It proceeds with a discussion of biochemical pathways that provide energy for brain work and also discusses the role of astrocytes in the regulation of the metabolic response to neuronal excitation. The chapter attempts to identify an alternative regulator that changes in response to work and influences the rate of energy metabolism.
Ultra-fast fMRI
Authors: Jones Richard A. , Brookes Jason A. , Moonen Chrit T.W. 
Published: April 2012

AbstractBrain activation is known to lead to enhanced perfusion which, together with other physiological changes, results in a decreased deoxyhaemoglobin concentration in regions of neuronal activity. This effect is referred to as the blood oxygenation level dependent (BOLD) effect. The main purpose of this chapter is to outline the acquisition methods for ultra-fast BOLD functional magnetic resonance imaging (fMRI). It helps to explain the basics of echo planar imaging and alternative ultra-fast imaging techniques, discusses possible artefacts and pitfalls, and also studies the requirements for BOLD fMRI acquisition methods, focusing on echo planar imaging (EPI). The chapter discusses the two basic types of spin echo sequences that have been employed for fMRI studies, namely multiple echo sequences and spin echo EPI. The methods discussed traverse k-space in a rectilinear fashion. Moreover, the chapter also describes promising recent developments and mentions that ultra-fast 3D methods are under development which will potentially provide better signal-to-noise ratio and BOLD contrast per unit time than EPI, and which are also less sensitive to inflow effects.
Effective paradigm design
Authors: Donaldson David I. , Buckner Randy L. 
Published: April 2012

AbstractAdvances in functional magnetic resonance imaging (fMRI) are affording numerous new ways to design and analyse brain-imaging studies. A major driving force for these advances has been the widespread use of MRI scanners capable of ultra-fast imaging. This chapter aims to review key aspects of magnetic resonance imaging (MRI) technology and of the underlying physiology that constrains paradigm design for functional brain imaging. It reviews issues related to the design of event-related experimental paradigms and discusses how event related procedures have extended the range of questions that can be dealt. The chapter introduces the concept of mixed ‘blocked and event-related’ procedures. The development of such ‘mixed’ procedures widens the spectrum of task designs and analytical techniques that can be used. The chapter also extends the range of questions that can be addressed with fMRI, and presents a brief review of the underlying characteristics of the haemodynamic response, to provide a framework for discussion of event-related methods and their derivatives.
The scanner as a psychophysical laboratory
Authors: Savoy Robert 
Published: April 2012

AbstractThere has been steady progress, both in individual laboratories and in the development of integrated commercial systems, for the sophisticated control of stimulus presentation and response recording during magnetic resonance imaging (MRI). This chapter articulates some of this progress and the general considerations for anyone establishing a functional MRI research environment, focusing on the latest developments relevant to an investigator establishing their own psychophysical laboratory in the magnet. The technical problem of stimulus presentation and response recording provides a brief discussion of the general need to adapt the psychophysical tasks themselves to be more compatible with the MRI environment. The chapter also discusses stimulus presentation, subdivided by modality (visual, auditory, tactile, etc.) and voluntary response recording, and furthermore deals with physiological response recording, head movement and related safety issues. Finally, it discusses the tradeoffs between commercial systems, custom designed systems and the goal of a completely integrated psychophysiological laboratory in the MRI environment.
Head motion and its correction
Authors: Brammer Mick J. 
Published: April 2012

AbstractThe aim of functional magnetic resonance imaging (fMRI) data analysis is, in simple terms, to identify small, spatially localized changes in image intensity that accompany the performance of some experimental task. It gives rise to some of the problems that relate to head motion and signal to noise ratio. The purpose of this chapter is to illustrate some of these problems and to discuss some of the methods that have been developed to counter them. The realization that head motion is a potentially serious confound in fMRI has led to the development of a number of strategies for dealing with this problem. The chapter further reveals that motion correction is a computationally expensive process and discusses the practical implications of motion correction. Finally, it shows that subject motion remains a potentially serious problem in fMRI and describes some of the available methodology and the practical impact of correction on activation mapping.
fMRI: applications to cognitive neuroscience
Authors: Owen Adrian M. , Epstein Russell , Johnsrude Ingrid S. 
Published: April 2012

AbstractThis chapter provides an exhaustive review of functional magnetic resonance imaging (fMRI) studies of cognitive function or of the achievements of this field as a whole. It focuses paradigmatically on the areas where fMRI has augmented existing knowledge obtained using other techniques via the combination of its particular technical properties, and their innovative application to the solution of diverse and novel problems in the field of human cognition and on the areas where fMRI has superseded alternative methodological approaches by providing more accurate, faster, safer or more cost-effective information than was previously available. The chapter addresses each of these areas and evaluates their current relevance to, and future impact on, our understanding of normal cognitive function in humans.
Why Develop a Neck?
Authors: Gans Carl 
Published: April 2012

AbstractThe Random House Dictionary defines the word “neck” as “the part of the body of an animal or man that connects the head and the trunk.” Therefore, in classical terms, the neck would only be expected to happen in animals that have heads different from their trunks. Heads are expected to serve the organism in roles such as ingestion, mating, sensation, and defense. Trunks are expected to have roles in visceral function such as reproduction, digestion, circulation, and respiration. Other significant roles of trunks are transport, maintenance of posture, as well as attachment.
The Head-Neck System of the BlowflyCalliphora:2. Functional Organization and Comparisons with the Sphinx MothManduca sexta
Authors: Milde Jürgen J. , Gronenberg Wulfila , Strausfeld Nicholas J. 
Published: April 2012

AbstractIn this chapter, the motion-sensitive responses of particular neck muscles motoneurons in the fly Calliphora erythrocephala are characterized and compared to those in an analogous system in the sphinx moth Manduca sexta. Even though both species are considerably separated on the phylogenetic tree, the main characteristics of the neck motor organization appear to be analogous, manifesting a normal “blueprint” for holometabolous insects. The chapter also demonstrates similarities between the response characteristics of visual neurons and neck motoneurons that are activated by specific direction and velocities of moving gratings. Lastly, the chapter demonstrates that descending visual interneurons do indeed respond to panoramic visual motion, as well as to mechanosensory stimuli that would be perceived during flight.
Reflex Contributions to the Control of Head Movement in the Lizard
Authors: Wang Dave H. B. , Anderson John H. 
Published: April 2012

AbstractThere are some tough problems in comprehending the control of head movements. The head-neck system is multijointed and the posture and the movement of the head can be controlled by distinct pairs of muscles that may subserve the same functions or help to perform a particular task. There seems to be considerable redundancy. The behavioral degrees of freedom are few, yet simple movements such as rotating the head may result from the contraction of many muscles acting in a coordinated manner manifesting the necessity for some constraints. Another problem is that different tasks may need to be performed and the organization of the sensory inputs and the motor outputs must be appropriate for a particular task, such as controlling gaze or posture or both at the same time.
Biomechanical Models of the Head-Neck System
Authors: Dimnet Johannes 
Published: April 2012

AbstractIn this chapter, a classification of biomechanical models of the head-neck system is proposed. Generally, these models are developed to study the responses of head-neck structures to impact and dynamic loading. In global models, in which dynamic loading is considered as input and ensuing displacements as output, the whole body acts as a black box whose mechanical components are determined in real time. In physical models, a human replica is constructed and instrumented. The behavior of the system under static loading is adjusted so as to correspond to that of a cadaver specimen. In numerical models, three-dimensional lumped-parameter models of the human head-neck system have been developed to predict the motion of the system under specific initial conditions.
Muscle Behavior May Solve Motor Coordination Problems
Authors: Hogan Neville , Mussa-lvaldi Ferdinando A. 
Published: April 2012

AbstractLike many biologic systems, one of the differentiating features of the head and neck is its mechanical intricacy. The head-neck system includes approximately thirty muscles; each spans multiple joints, and each joint has multiple degrees of freedom. The sensory system includes several radically different types of sensory organs. At first, this intricacy may seem tough, yet it must be confronted squarely if a deep comprehension of sensory-motor coordination is to be made. One aspect of sensory-motor coordination that is epitomized by the head-neck system is the general problem of coordinate transformations. The root of the problem is that several parts of the process of doing an action in response to sensory stimuli are each largely described in their own terms.
Somatosensory Pathways from the Neck
Authors: Tracey David J. , Bolton Philip S. 
Published: April 2012

AbstractThe neck is full of mechanoreceptors that play a significant role in the control of posture. However, it is only lately that we have gathered detailed information about the terminations of these receptors in the spinal cord and medulla, and comparatively little was known about their main connections and the ascending pathways that convey data from neck receptors to higher centers. The ascending pathways that convey data from somatosensory receptors to the cerebral cortex have been studied for many years. For technical reasons, most early research was executed on pathways from mechanoreceptors in the hindlimb of the cat, which involve medullary relays in the gracile nucleus and nucleus z.
Physiologic Properties and Central Actions of Neck Muscle Spindles
Authors: Wilson Victor J. 
Published: April 2012

AbstractActivation of proprioceptors in the neck suggests reflexes that are abundant in the decerebrate cat and presumably contribute to the posture of the alert, behaving animal. Because they appear to contribute afferent input to these reflexes, the properties of neck muscles spindles are of considerable interest. Their distribution and structure have been studied in great detail and described in recent reviews. This chapter discusses their dynamic behaviors and their role in segmental stretch reflexes and their relation with the vestibular system. The first physiologic research on neck muscle spindles were those by Richmond and Abrahams who recorded from single dorsal root fibers in anesthetized cats paralyzed by Flaxedil.
Eye and Neck Proprioceptive Messages Contribute to the Specification of Gaze Direction in Visually Oriented Activities
Authors: Roll Régine , velay Jean Louis , Roll Jean-pierre 
Published: April 2012

AbstractWhen talking about proprioceptive knowledge of eye position sense, Steinbach pointed out that: “a most vexing problem in trying to understand the role of proprioception is to come up with some clear, unequivocal evidence for its function.” In this chapter, the authors provide some experimental evidence in favor of the functional contribution of eye and neck proprioceptive afferents to visually oriented activities. The fact that the most behavioral activities are based first and foremost on the visual grasping of a target says that the gaze direction might play a crucial role in body and limb orientation. The exact nature and origin of the extraretinal signal have not yet been firmly established.
Influence of Neck Receptor Stimulation on Eye Rotation and on the Subjective Vertical: Experiments on the Tilt Table, under Water, and in Weightlessness
Authors: Wetzig Joachim , Baumgarten Rudolf J. Von 
Published: April 2012

AbstractSince the head is pivoted in all directions on the trunk, verticality of the trunk and equilibrium must be computed from at least two sources, the otolith system and the proprioceptive system of the neck. To study the influence of neck receptors on subjective space orientation and on eye movement is quite a tough task because most procedures on the ground include neck receptor stimulation and the vestibular organ at the same time. Experiments were conducted on a land-based special tilt table that allows tilting the whole body together with the head or tilting the head relative to the body or maintaining a fixed position of the head while deflecting the body against the head.
Cervico-ocular Reflexes with and without Simultaneous Vestibular Stimulation in Rabbits
Authors: Barmack Neal H. , Errico Pierangelo , Ferraresi Aldo , Pettorossi Vito E. 
Published: April 2012

AbstractThe horizontal cervico-ocular reflex (HCOR) comprises compensatory eye movements that are evoked by rotation of the body about the fixed head. This head goes together with the horizontal vestibulo-ocular reflex (HVOR) in the sense that a counterclockwise rotation of the body about the fixed head evokes a counter clockwise compensatory eye movement. This counterclockwise eye movement is evoked if the head and body are rotated in a clockwise direction or if the head is rotated clockwise about the body. The gain of the HCOR is maximal for relatively low-frequency stimuli. In addition to the compensatory slow-phase eye movement, the HCOR is depicted by a fast-phase eye movement that is compensatory as well.
Gravitational, Inertial, and Coriolis Force Influences on Nystagmus, Motion Sickness, and Perceived Head Trajectory
Authors: Lackner James R. , DiZio Paul 
Published: April 2012

AbstractAn intricate pattern of stimulation is generated when a rotating individual tilts his head about an axis that is not parallel to the axis of rotation. His semicircular canals undergo cross-coupled angular accelerations, and his head and otolith organs are exposed to a Coriolis force. Such head movements elicit nystagmus, motion sickness symptoms, and disorientation. The disorientation has two major components: during the head movement, the individual will misperceive the actual trajectory of his head in relation to his torso, and for some time afterward, he will have a confusing illusion that his whole body is rotating. If an individual seated at the center of the platform rotating counterclockwise at constant angular velocity tilts his head backward, then his yaw canal receives a clockwise velocity impulse because it loses angular momentum on moving out of the plane of rotation.
Eye and Head Movements as Specialized Functions of Vestibular Circuits
Authors: Schaefer Kurt-peter , Lothar Meyer Dietrich 
Published: April 2012

AbstractThe aim of this chapter is to focus on the huge extent to which eye-head movements mirror specialized functions of the vestibular system, or circuits derived from this system. Accordingly, the authors argue that many of the physiologic phenomena described can only be understood if the evolutionary background is appreciated. Apparently, evolution shaped the vestibular systems long before a mobile neck evolved, and the “problems” under consideration at this conference were created by nature. Originally, the vestibular system's main function has been to stabilize the eyes in space during active and passive body movements. Without such a mechanism, visual functions would be significantly impaired.
Properties of Vestibulo-ocular and/or Vestibulocollic Neurons in the Cat
Authors: Uchino Yoshio , Isu Naoki 
Published: April 2012

AbstractThe vestibulo-ocular reflexes help to stabilize the visual image on the retina, and the vestibulocollic (vestibular neck) reflexes play a role in restoring the head position in space during head movements. The vestibular nucleus neurons play a crucial role in both reflex pathways. It was observed that individual vestibular relay neurons receive inputs from two to three semicircular canal pairs, or from canals and otolith organs, when natural stimuli were applied in alert cats. However, according to observations in anesthetized cats, it has been considered that the primary afferent fibers from each semicircular canal have their own target neurons in the vestibular nuclei.
Involvement of the Interstitial Nucleus of Cajal in the Midbrain Reticular Formation in the Position-Related, Tonic Component of Vertical Eye Movement and Head Posture
Authors: Fukushima Kikuro , Fukushima Junko 
Published: April 2012

AbstractThe interstitial nucleus of Cajal (INC) in the midbrain reticular formation, which has a reciprocal connection with the vestibular and prepositus nuclei, sends major outputs to the oculomotor and neck motor nuclei. This chapter discusses four major research findings that suggest that the midbrain region within, and in the close vicinity of, the INC is involved in vertical eye position generation in saccades and the vestibulo-ocular reflex (VOR). Involvement of the INC region in the control head posture is reviewed thereafter. Vertical eye position after saccade is not maintained in cats with bilateral lesions in the INC; the vertical VOR is impaired by bilateral lesions of the INC; average discharge rate during vertical saccades is significantly positively correlated with tonic discharge rate; and gain of response of vertical burst-tonic neurons to pitch rotation changes.
Electromyographic Activity of Neck Muscles in Relation to the Initiation of Head Turning Induced by Stimulation of the Caudate Nucleus in the Cat
Authors: Ohno Tadao , Tsubokawa Hiroshio 
Published: April 2012

AbstractElectrical stimulation of the caudate nucleus on one side induces a contraversive lateral fixation of the neck which is often followed by postural asymmetry and circling in the cat and other species. Caudate-induced HT (Cd-HT) can be regarded as being closely related to a process of the postural control exerted by the basal ganglia. Conversely, lesions in the striatum of the rat produced by both kainic acid and 6-hydroxydopamine resulted in impairment in sensory-motor orientation of the head to contralateral stimuli. Hassler and Dieckmann recorded that eye and head movements in the same direction were induced by stimulation of the pallidum of the cat. The effects of stimulation of the caudate nucleus on eye movements, however, have not been analyzed systematically.
Multidimensional Analysis of Head Stabilization—Progress and Prospects
Authors: Peterson Barry W. , Baker James F. , Keshner Emily A. 
Published: April 2012

AbstractThe ultimate objective in studying the vestibulocollic (VCR) and cervicocollic (CCR) reflexes is to understand their dynamic and spatial properties at three levels: the kinetics of movement of the head, neck vertebrae, and neck muscles following perturbation of the body in any direction; the dynamics of activation of each class of receptor and each neck muscle; and spatial and dynamic properties of neuronal circuits that transform receptor input to muscle output. Current progress and future prospects for understanding each of these aspects are summarized. Three-dimensional power spectral characteristics of movements of the head-neck system have been measured during functional activities. Significant power was observed in the pitch and yaw planes, with the wider bandwidth for pitch occurring for walking in place.
Eye-Head Main Sequence in Midsagittal Vertical Plane in Humans
Authors: André-deshays Claudie , Ron Samuel 
Published: April 2012

AbstractThe vertical gaze displacement has seldom been studied systematically. Also, gaze-orienting movement in the vertical plane to a continuously visible target offset has not been investigated. The main sequence of eye saccade and head movement was studied in three subjects in order to determine the eye and head contributions to gaze in the midsagittal plane under visually guided conditions. The methods conducted were the one with a bite board in a head-fixed condition and the one with a head-free condition. The main finding in these experiments was that the saccade main sequence in the vertical midsagittal plane is asymmetrical for upward and downward saccades, particularly for those larger than 20°.
Mechanisms of Gaze Control and Eye-Head Coupling in the Cat Whose Head is Unrestrained
Authors: Guitton Daniel , Munoz Douglas P. , Galiana Henrietta L. 
Published: April 2012

AbstractThere is evidence supporting the existence of common driver signals to the eye and head motor systems. Moreover, there are observations related to the broad mosaic of movement strategies in head-free gaze shifts. In this chapter, the experimental observations that probe the degree of coupling between the eye and head motor systems during gaze shifts made by the head-free cat are reviewed. The authors consider different experimental paradigms which could affect the metrics of saccades in head-fixed animals. The covariation of eye and head movement metrics in different behavioral tasks is discussed here, as well as the evidence that eye motor signals drive head motion.
Modeling Head-Free Gaze Control in the Cat
Authors: Galiana Henrietta L. , Guitton Daniel , Munoz and Douglas P. 
Published: April 2012

AbstractTwo primary issues are being studied in relation to the control of coordinated eye and head movements. The first one is the possible interaction of the vestibulo-ocular reflex (VOR) during the saccadic component of a gaze shift and the second one is the possible coordination of eye and head trajectors through shared access to a common premotor drive. This chapter presents an alternate view of central eye-head coordination, using global gaze error as a precursor of motoneural drives. The model of eye-head coupling is also conceptually justified in this chapter. Some simulation examples are presented, including the gaze shifts within and beyond the oculomotor range and coupling of eye and head trajectories.