Search results for "lateralization"

Beta Rebound as an Index of Temporal Integration of Somatosensory and Motor Signals

2020

Modulation of cortical beta rhythm (15-30 Hz) is present during preparation for and execution of voluntary movements as well as during somatosensory stimulation. A rebound in beta synchronization is observed after the end of voluntary movements as well as after somatosensory stimulation and is believed to describe the return to baseline of sensorimotor networks. However, the contribution of efferent and afferent signals to the beta rebound remains poorly understood. Here, we applied electrical median nerve stimulation (MNS) to the right side followed by transcranial magnetic stimulation (TMS) on the left primary motor cortex after either 15 or 25 ms. Because the afferent volley reaches the …

Causal brain-heart information transfer during visual emotional elicitation in healthy subjects: Preliminary evaluations and future perspectives

2017

Complex heartbeat dynamics is known to reflect subject's emotional state, thanks to numerous links to brain cortical and subcortical regions. Likewise, specific brain regions are deeply involved in vagally-mediated emotional processing and regulation. Nevertheless, although the brain-heart interplay has been studied during visual emotion elicitation, directional interactions have not been investigated so far. To fill this gap, in this study we investigate brain-heart dynamics during emotional elicitation in healthy subjects through measures of Granger causality (GC) between the two physiological systems. Data were gathered from 22 healthy volunteers who underwent pleasant/ unpleasant affect…

P26-S Left and right motor cortical excitability and relationship to motor functions in healthy adolescents

2019

Background The interhemispheric difference in cortical excitability and its relationship to motor functions is unclear. Aim We examined the relationship between handedness, left and right motor cortex excitability and fine and gross motor functions in adolescence. Methods 28 healthy adolescents (age 16–19 years, 19 girls) were studied. Handedness was determined by the Waterloo Handedness Questionnaire. Motor threshold (MT) of the abductor pollicis brevis was measured on both hemispheres using biphasic stimulation, and on the left hemisphere also with monophasic stimulation. Box and block test (BBT) was used for manual dexterity, line run and standing long jump for gross motor tasks. Spearma…

2016

The neural systems supporting speech and sign processing are very similar, although not identical. In a previous fTCD study of hearing native signers (Gutierrez-Sigut, Daws, et al., 2015) we found stronger left lateralization for sign than speech. Given that this increased lateralization could not be explained by hand movement alone, the contribution of motor movement versus ‘linguistic’ processes to the strength of hemispheric lateralization during sign production remains unclear. Here we directly contrast lateralization strength of covert versus overt signing during phonological and semantic fluency tasks. To address the possibility that hearing native signers’ elevated lateralization ind…

Transposed-letter and laterality effects in lexical decision.

2006

Two divided visual field lexical decision experiments were conducted to examine the role of the cerebral hemispheres in transposed-letter similarity effects. In Experiment 1, we created two types of nonwords: nonadjacent transposed-letter nonwords (TRADEGIA; the base word was TRAGEDIA, the Spanish for TRAGEDY) and two-letter different nonwords (orthographic controls: TRATEPIA). In Experiment 2, the controls were one-letter different nonwords (TRAGEPIA) instead of two-letter different nonwords (TRATEPIA). The effect of transposed-letter similarity was substantially greater in the right visual field (left hemisphere) than in the left visual field. Furthermore, nonwords created by transposing …

A combined therapy for limb apraxia and related anosognosia.

2019

Left hemisphere stroke frequently leads to limb apraxia, a disorder that has been reported to impact independence in daily life and rehabilitation success. Nonetheless, there is a shortcoming in research and availability of applicable trainings. Further, to date, anosognosia for limb apraxia has largely been neglected. Therefore, we developed a Naturalistic Action Therapy that trains object selection and application with an errorless learning approach and which includes supported self-evaluation. The current study presents the results of two stroke patients participating in the training. The procedure entailed two baseline and one post-training sessions including standardized limb apraxia a…

Continuous theta burst stimulation (cTBS) on left cerebellar hemisphere affects mental rotation tasks during music listening.

2013

Converging evidence suggests an association between spatial and music domains. A cerebellar role in music-related information processing as well as in spatial-temporal tasks has been documented. Here, we investigated the cerebellar role in the association between spatial and musical domains, by testing performances in embodied (EMR) or abstract (AMR) mental rotation tasks of subjects listening Mozart Sonata K.448, which is reported to improve spatial-temporal reasoning, in the presence or in the absence of continuous theta burst stimulation (cTBS) of the left cerebellar hemisphere. In the absence of cerebellar cTBS, music listening did not influence either MR task, thus not revealing a “Moz…

Change detection to tone pairs during the first year of life – Predictive longitudinal relationships for EEG-based source and time-frequency measures

2019

Abstract Brain responses related to auditory processing show large changes throughout infancy and childhood with some evidence that the two hemispheres might mature at different rates. Differing rates of hemispheric maturation could be linked to the proposed functional specialization of the hemispheres in which the left auditory cortex engages in analysis of precise timing information whereas the right auditory cortex focuses on analysis of sound frequency. Here the auditory change detection process for rapidly presented tone-pairs was examined in a longitudinal sample of infants at the age of 6 and 12 months using EEG. The ERP response related to change detection of a frequency contrast, i…

Auditory event-related potentials measured in kindergarten predict later reading problems at school age.

2013

Identifying children at risk for reading problems or dyslexia at kindergarten age could improve support for beginning readers. Brain event-related potentials (ERPs) were measured for temporally complex pseudowords and corresponding non-speech stimuli from 6.5-year-old children who participated in behavioral literacy tests again at 9 years in the second grade. Children who had reading problems at school age had larger N250 responses to speech and non-speech stimuli particularly at the left hemisphere. The brain responses also correlated with reading skills. The results suggest that atypical auditory and speech processing are a neural-level risk factor for future reading problems. [Supplement…

FOXP2 expression and gray matter density in the male brains of patients with schizophrenia

2021

Common genetic variants ofFOXP2may contribute to schizophrenia vulnerability, but controversial results have been reported for this proposal. Here we evaluated the potential impact of the commonFOXP2rs2396753 polymorphism in schizophrenia. It was previously reported to be part of a risk haplotype for this disease and to have significant effects on gray matter concentration in the patients. We undertook the first examination into whether rs2396753 affects the brain expression ofFOXP2and a replication study of earlier neuroimaging findings of the influence of this genetic variant on brain structure.FOXP2expression levels were measured in postmortem prefrontal cortex samples of 84 male subject…