Search results for "prism adaptation"
showing 10 items of 16 documents
Heteroforiju izmaiņas pēc ilgstošas disociācijas un prizmu adaptācijs testa
2021
Maģistra darbs ir uzrakstīts angļu valodā uz 46 lapām. Tas satur 14 attēlus, 8 tabulas un 80 atsauces uz literatūras avotiem. Mērķis bija izvērtēt verģences adaptācijas ietekmi uz heteroforiju novērtējumu un prizmu adaptācijas testa pielietojumu klīniskajā praksē. Pirmajā daļā 40 dalībniekiem tika novērtētas heteroforija izmaiņas 2 minūšu laikā pēc disociācijas. Otrajā daļā tika novērtēta verģences adaptācija, izmantojot prizmu adaptācijas testu. Rezultāti parādīja, ka heteroforijas lielumu būtiski ietekmē disociācijas ilgums. Dalībniekiem ar diagnosticētu verģences anomāliju novēroja samazinātu verģences adaptāciju. Secinājums: verģences adaptācijai ir nozīmīga ietekme uz heteroforijas nov…
Prism adaptation and neck muscle vibration in healthy individuals: Are two methods better than one?
2013
Studies involving therapeutic combinations reveal an important benefit in the rehabilitation of neglect patients when compared to single therapies. In light of these observations our present work examines, in healthy individuals, sensorimotor and cognitive after-effects of prism adaptation and neck muscle vibration applied individually or simultaneously. We explored sensorimotor after-effects on visuo-manual open-loop pointing, visual and proprioceptive straight-ahead estimations. We assessed cognitive after-effects on the line bisection task. Fifty-four healthy participants were divided into six groups designated according to the exposure procedure used with each: 'Prism' (P) group; 'Vibra…
Modifying auditory perception with prisms? Aftereffects of prism adaptation on a wide auditory spectrum in musicians and nonmusicians
2021
Prism adaptation consists of pointing to visual targets while wearing prisms that shift the visual field laterally. The aftereffects are not restricted to sensorimotor level but extend to spatial cognition. There is a link between spatial representation and auditory frequency, with an association of low frequencies on the left side and high frequencies on the right side of space. The present study aimed first at evaluating the representation of auditory frequencies on a wide range of frequencies in musicians and nonmusicians. We used the ‘auditory interval bisection judgment’ within three auditory intervals. The results showed a pseudoneglect behavior in pretest in musicians and nonmusician…
Does force-field adaptation induce after-effects on space representation?
2017
AbstractPrism adaptation is a well-known model to study sensorimotor adaptive processes. It has been shown that following prism exposure, after-effects are not only restricted to the sensorimotor level but extend as well into spatial cognition. The main purpose of the present study was to investigate in healthy individuals whether expansion to spatial cognition is restricted to adaptive processes peculiar to prism adaptation or whether it occurs as well following other forms of adaptive process such as adaptation to a novel dynamic environment during pointing movements. Representational after-effects were assessed by the perceptual line bisection task before and after adaptation to a leftwa…
Boosting Phonological Fluency Following Leftward Prismatic Adaptation: A New Neuromodulation Protocol for Neurological Deficits?
2020
Abstract Prism adaptation (PA) has been recently shown to modulate a brain frontal-parieto-temporal network, with an increase of excitation of this network in the hemisphere ipsilateral to the side of prismatic deviation. This effect raises the hypothesis that left prismatic adaptation, modulating the excitability of frontal areas of the left hemisphere, could modulate subjects’ performance on linguistic tasks that map on those areas.To test this hypothesis, sixty-one healthy subjects participated in experiments in which leftward, rightward or no-PA were applied before the execution of a phonological fluency task, i.e. a task with strict left hemispheric lateralization and mapping onto fron…
Beyond the sensorimotor plasticity: cognitive expansion of prism adaptation in healthy individuals.
2016
Sensorimotor plasticity allows us to maintain an efficient motor behavior in reaction to environmental changes. One of the classical models for the study of sensorimotor plasticity is prism adaptation. It consists of pointing to visual targets while wearing prismatic lenses that shift the visual field laterally. The conditions of the development of the plasticity and the sensorimotor after-effects have been extensively studied for more than a century. However, the interest taken in this phenomenon was considerably increased since the demonstration of neglect rehabilitation following prism adaptation by Rossetti and his colleagues in 1998. Mirror effects, i.e. simulation of neglect in health…
Improvement of phonemic fluency following leftward prism adaptation.
2021
AbstractAnatomo functional studies of prism adaptation (PA) have been shown to modulate a brain frontal-parieto-temporal network, increasing activation of this network in the hemisphere ipsilateral to the side of prism deviation. This effect raises the hypothesis that left prism adaptation, modulating frontal areas of the left hemisphere, could modify subjects’ performance on linguistic tasks that map on those areas. To test this hypothesis, 51 healthy subjects participated in experiments in which leftward or rightward prism adaptation were applied before the execution of a phonemic fluency task, i.e., a task with strict left hemispheric lateralization onto frontal areas. Results showed tha…
Cross-modal aftereffects of visuo-manual prism adaptation: Transfer to auditory divided attention in healthy subjects.
2021
OBJECTIVE Prism adaptation was shown to modify auditory perception. Using a dichotic listening task, which assesses auditory divided attention, benefits of a rightward prism adaptation were demonstrated in neglect patients (i.e., a syndrome following right hemisphere brain damage) by reducing their left auditory extinction. It is currently unknown whether prism adaptation affects auditory divided attention in healthy subjects. In the present study, we investigated the aftereffects of prism adaptation on dichotic listening. METHOD A sample of 47 young adults performed a dichotic listening task, in which pairs of words were presented with two words sounded simultaneously, one in each ear. Thr…
Prism adaptation power on spatial cognition: Adaptation to different optical deviations in healthy individuals
2015
The main objective of the present study was to determine the minimal optical deviation responsible for cognitive after-effects in healthy individuals and to explore whether there was a relationship between the degree of optical deviation and cognitive after-effects. Therefore different leftward optical deviations (8°, 10° and 15°) were used in three different groups of healthy participants. Sensorimotor after-effects (evaluating the visuo-manual realignment) were assessed using an open-loop pointing task and cognitive after-effects (evaluating changes in spatial representation) were assessed using manual and perceptual (landmark) line bisection tasks. Results revealed that exposure to 8°, 1…
Testing cognition and rehabilitation in unilateral neglect with wedge prism adaptation: multiple interplays between sensorimotor adaptation and spati…
2014
Spatial neglect is a neurological condition characterised by deficits for perceiving, attending, representing, and/or performing actions within their left-sided space, responsible for numerous debilitating effects in everyday life, for poor functional recovery, and for decreased ability to benefit from treatment. Exposure to a right lateral displacement of the visual field (induced by a simple target-pointing task with base-left wedge prisms) is known to directionally bias visuomotor coordination and can be compensated by both sensorimotor adaptation and cognitive processes. Sensorimotor adaptation gives rise to after-effects whose duration is amplified in neglect patients and has been repe…