Vestibulo-ocular and optokinetic impairments in left unilateral neglect

Doricchi, Fabrizio; Siegler, Isabelle; Iaria, Giuseppe; Berthoz, Alain

doi:10.1016/s0028-3932(02)00049-0

Cited by 25 publications

(7 citation statements)

References 60 publications

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“…This effect on the spatial reference frame may explain how right PA improves the complex of symptoms in neglect. Vestibular input is important for maintaining spatial orientation (Ventre-Dominey et al, 1999;Doricchi et al, 2002) and plays a role in neglect (Cappa et al, 1987;Vallar et al, 1993). For example, irrigation of the right ear with cold water, to cause convection in the endolymph of the vestibular apparatus and stimulate vestibular signaling, improves spatial functioning in neglect patients.…”

Section: Neuroimaging Resultsmentioning

confidence: 99%

Prism adaptation modulates connectivity of the intraparietal sulcus with multiple brain networks

Schintu

Freedberg

Gotts

et al. 2019

Preprint

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ABSTRACTPrism adaptation (PA) alters spatial cognition according to the direction of visual displacement by temporarily modifying sensorimotor mapping. Right-shifting prisms (right PA) improve neglect of left space in patients, possibly by decreasing activity in the left hemisphere and increasing it in the right. Left PA shifts attention to the right in healthy individuals by an opposite mechanism. However, functional imaging studies of PA are inconsistent, perhaps because of differing activation tasks. We measured resting-state functional connectivity (RSFC) in healthy individuals before and after PA. Right, vs. left, PA decreased RSFC in the navigation network defined by the right posterior parietal cortices (PPCs), hippocampus, and cerebellum. Right PA, relative to baseline, increased RSFC between regions within both PPCs and between the PPCs and the right middle frontal gyrus, whereas left PA decreased RSFC between these regions. These results show that right PA modulates connectivity within the right-hemisphere navigation network and shifts attention leftward by increasing connectivity in the right frontoparietal network and left PA produces essentially opposite effects, consistent with the interhemispheric competition model. These finding explain the action of PA on intact cognition and will help optimize interventions in neglect patients.

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Section: Neuroimaging Resultsmentioning

confidence: 99%

Prism adaptation modulates connectivity of the intraparietal sulcus with multiple brain networks

Schintu

Freedberg

Gotts

et al. 2019

Preprint

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“…There is indirect evidence to suggest that the vestibular cortex can modulate the function of vestibular reflexes, presumably via cortico‐bulbar projections (Doricchi et al . ; Ventre‐Dominey et al . ; Marsden et al .…”

Section: Discussionmentioning

confidence: 99%

“…Likewise, VOR gain and bias have been shown to be affected by neglect caused by cortical damage (Doricchi et al . ; Ventre‐Dominey et al . ), hemispheric dominance (Arshad et al .…”

Section: Discussionmentioning

confidence: 99%

Modulation of human vestibular reflexes with increased postural threat

Horslen

Dakin

Inglis

et al. 2014

The Journal of Physiology

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Key pointsr The vestibular system is an important sensory contributor to the control of standing balance. r Fear, anxiety and arousal are thought to influence the excitability of the vestibular system, but it is not clear if these changes lead to altered vestibular-evoked balance reflexes.r Low and high standing surface heights were used to manipulate fear and anxiety in this study, while stochastic vestibular stimulation was used to evoke balance reflexes. r These results support the idea that the manner in which vestibular information is processed is altered when people are exposed to a threat to their balance, and this altered processing may explain why normal balance behaviour is different in threatening scenarios.Abstract Anxiety and arousal have been shown to facilitate human vestibulo-ocular reflexes, presumably through direct neural connections between the vestibular nuclei and emotional processing areas of the brain. However, the effects of anxiety, fear and arousal on balance-relevant vestibular reflexes are currently unknown. The purpose of this study was to manipulate standing height to determine whether anxiety and fear can modulate the direct relationship between vestibular signals and balance reflexes during stance. Stochastic vestibular stimulation (SVS; 2-25 Hz) was used to evoke ground reaction forces (GRF) while subjects stood in both LOW and HIGH surface height conditions. Two separate experiments were conducted to investigate the SVS-GRF relationship, in terms of coupling (coherence and cumulant density) and gain, in the medio-lateral (ML) and antero-posterior (AP) directions. The short-and medium-latency cumulant density peaks were both significantly increased in the ML and AP directions when standing in HIGH, compared to LOW, conditions. Likewise, coherence was statistically greater between 4.3 Hz and 6.7 Hz in the ML, and between 5.5 and 17.7 Hz in the AP direction. When standing in the HIGH condition, the gain of the SVS-GRF relationship was increased 81% in the ML direction, and 231% in the AP direction. The significant increases in coupling and gain observed in both experiments demonstrate that vestibular-evoked balance responses are augmented in states of height-induced postural threat. These data support the possibility that fear or anxiety-mediated changes to balance control are affected by altered central processing of vestibular information.

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“…In humans, cold water irrigation of one ear typically activates the temporo-parietal cortex, the insula, the putamen, and the anterior cingulate in the contralateral hemisphere (Bottini, Sterzi, et al, 1994). This ''vestibular cortical system'' not only receives afferent vestibular inputs, but also modulates ocular vestibular responses through efferent connections the to vestibular nuclei (Doricchi, Siegler, Iaria, & Berthoz, 2002;Ventre-Dominey, Vighetto, & Denise, 1999). A PET study by Bottini, Paulesu, et al (1995) suggests that in right brain-damaged patients cold caloric vestibular stimulation reduces contralesional somatosensory deficits (i.e., hemianesthesia) by activating spared secondary somatosensory cortices where both tactile and vestibular signals are received (Johansen-Berg, Christensen, Woolrich, & Matthews, 2000).…”

Section: Discussionmentioning

confidence: 99%

Effects of Vestibular Rotatory Accelerations on Covert Attentional Orienting in Vision and Touch

Figliozzi

Guariglia

Silvetti

et al. 2005

Journal of Cognitive Neuroscience

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Abstract& Peripheral vestibular organs feed the central nervous system with inputs favoring the correct perception of space during head and body motion. Applying temporal order judgments (TOJs) to pairs of simultaneous or asynchronous stimuli presented in the left and right egocentric space, we evaluated the influence of leftward and rightward vestibular rotatory accelerations given around the vertical head-body axis on covert attentional orienting. In a first experiment, we presented visual stimuli in the left and right hemifield. In a second experiment, tactile stimuli were presented to hands lying on their anatomical side or in a crossed position across the sagittal body midline. In both experiments, stimuli were presented while normal subjects suppressed or did not suppress the vestibulo-ocular response (VOR) evoked by head-body rotation. Independently of VOR suppression, visual and tactile stimuli presented on the side of rotation were judged to precede simultaneous stimuli presented on the side opposite the rotation. When limbs were crossed, attentional facilitatory effects were only observed for stimuli presented to the right hand lying in the left hemispace during leftward rotatory trials with VOR suppression. This result points to spatiotopic rather than somatotopic influences of vestibular inputs, suggesting that cross-modal effects of these inputs on tactile ones operate on a representation of space that is updated following arm crossing. In a third control experiment, we demonstrated that temporal prioritization of stimuli presented on the side of rotation was not determined by response bias linked to spatial compatibility between the directions of rotation and the directional labels used in TOJs (i.e., ''left'' or ''right'' first). These findings suggest that during passive rotatory head-body accelerations, covert attention is shifted toward the direction of rotation and the direction of the fast phases of the VOR. &

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Vestibulo-ocular and optokinetic impairments in left unilateral neglect

Cited by 25 publications

References 60 publications

Prism adaptation modulates connectivity of the intraparietal sulcus with multiple brain networks

Prism adaptation modulates connectivity of the intraparietal sulcus with multiple brain networks

Modulation of human vestibular reflexes with increased postural threat

Effects of Vestibular Rotatory Accelerations on Covert Attentional Orienting in Vision and Touch

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