Search results for "Lateralization of brain function"
showing 10 items of 110 documents
Melanism is related to behavioural lateralization in nestling barn owls.
2017
5 pages; International audience; Behavioural laterality is a commonly observed phenomenon in many species suggesting there might be an advantage of using dominantly one side over the other for certain tasks. Indeed, lateralized individuals were often shown to be more successful in cognitive tasks compared to non-lateralized conspecifics. However, stressed individuals are also often, but not always, more strongly lateralized. Because barn owl (Tyto alba) females displaying larger black spots on the tip of their ventral feathers produce offspring that are more resistant to a variety of environmental stressful factors, we examined whether laterality is associated with melanin-based coloration.…
Lateralization of complex behaviours in wild greater flamingos.
2018
8 pages; International audience; Lateralization refers to the preferential use of one side of the body to perform certain tasks, often as a consequence of the specialization of cerebral hemispheres. Individuals may benefit from lateralization if it allows them to perform complex tasks simultaneously. Studies on laterality further suggest that sex and age can influence the extent of lateralization. However, most studies on lateralization have been performed on captive individuals, exposed to simplified environments and expressing limited behavioural repertoire. Here, we evaluated behavioural lateralization in the greater flamingo, Phoenicopterus roseus, through observations of wild individua…
Differential contributions of the two human cerebral hemispheres to action timing
2019
Rhythmic actions benefit from synchronization with external events. Auditory-paced finger tapping studies indicate the two cerebral hemispheres preferentially control different rhythms. It is unclear whether left-lateralized processing of faster rhythms and right-lateralized processing of slower rhythms bases upon hemispheric timing differences that arise in the motor or sensory system or whether asymmetry results from lateralized sensorimotor interactions. We measured fMRI and MEG during symmetric finger tapping, in which fast tapping was defined as auditory-motor synchronization at 2.5 Hz. Slow tapping corresponded to tapping to every fourth auditory beat (0.625 Hz). We demonstrate that t…
Temporal-spatial characteristics of phase-amplitude coupling in electrocorticogram for human temporal lobe epilepsy.
2017
Objective Neural activity of the epileptic human brain contains low- and high-frequency oscillations in different frequency bands, some of which have been used as reliable biomarkers of the epileptogenic brain areas. However, the relationship between the low- and high-frequency oscillations in different cortical areas during the period from pre-seizure to post-seizure has not been completely clarified. Methods We recorded electrocorticogram data from the temporal lobe and hippocampus of seven patients with temporal lobe epilepsy. The modulation index based on the Kullback-Leibler distance and the phase-amplitude coupling co-modulogram were adopted to quantify the coupling strength between t…
Exploring the neural correlates of the reversed letter effect: Evidence from left and right parietal patients.
2019
To investigate the hemispheric lateralization of attentional processes during visual search tasks depending on the stimulus material embedding the target, twelve patients with unilateral left (n = 7) or right (n = 5) parietal lesions and 20 age and education matched healthy controls (HC) were recruited. We used a visual search task for a uniquely tilted oblique bar embedded in an object shape 'N' or in its mirror reversal 'И'. The accuracy and the averaged reaction times (RTs) in each stimulus type ('N' or 'И') were analysed.\ud \ud HC presented significantly longer RTs when the target bar was embedded in 'N' among its mirror reversed 'И' (p < .05). This “reversed letter effect” was also…
Left hemisphere enhancement of auditory activation in language impaired children
2019
| openaire: EC/H2020/641652/EU//ChildBrain Specific language impairment (SLI) is a developmental disorder linked to deficient auditory processing. In this magnetoencephalography (MEG) study we investigated a specific prolonged auditory response (N250m) that has been reported predominantly in children and is associated with level of language skills. We recorded auditory responses evoked by sine-wave tones presented alternately to the right and left ear of 9–10-year-old children with SLI (n = 10) and children with typical language development (n = 10). Source analysis was used to isolate the N250m response in the left and right hemisphere. In children with language impairment left-hemisphere …
Structural changes induced by daily music listening in the recovering brain after middle cerebral artery stroke: a voxel-based morphometry study
2014
[Abstract.] Music is a highly complex and versatile stimulus for the brain that engages many temporal, frontal, parietal, cerebellar, and subcortical areas involved in auditory, cognitive, emotional, and motor processing. Regular musical activities have been shown to effectively enhance the structure and function of many brain areas, making music a potential tool also in neuro- logical rehabilitation. In our previous randomized controlled study, we found that listening to music on a daily basis can improve cognitive recovery and improve mood after an acute mid- dle cerebral artery stroke. Extending this study, a voxel-based morphometry (VBM) analysis utilizing cost function masking was perf…
Salivary testosterone is related to both handedness and degree of linguistic lateralization in normal women.
2003
The aim of this study was to test the hypothesis that individual differences in testosterone (T) are associated with different patterns of linguistic lateralization and hand preference. Twenty left-handed (LH) and 19 right-handed (RH) women filled in a handedness questionnaire and performed a consonant–vowel dichotic listening test (DL-CV). Salivary T was measured by radioimmunoassay (RIA). LH women showed significantly lower mean salivary T than RH women. T levels were negatively correlated with the absolute value of the DL laterality index. Subjects with right ear advantage (REA) were classified into strongly and weakly lateralized following Wexler et al. method (Brain Lang. 13 (1981) 13)…
Lateralization of directional brain-heart information transfer during visual emotional elicitation
2019
Previous studies have characterized the physiological interactions between central nervous system (brain) and peripheral cardiovascular system (heart) during affective elicitation in healthy subjects; however, questions related to the directionality of this functional interplay have been gaining less attention from the scientific community. Here, we explore brain-heart interactions during visual emotional elicitation in healthy subjects using measures of Granger causality (GC), a widely used descriptor of causal influences between two dynamical systems. The proposed approach inferences causality between instantaneous cardiovagal dynamics estimated from inhomogeneous point-process models of…
Asymmetry in dopamine D2/3 receptors of caudate nucleus is lost with age
2007
Molecular and functional imaging techniques reveal evidence for lateralization of human cerebral function. Based on animal data, we hypothesized that asymmetry in dopamine neurotransmission declines during normal aging. In order to test this hypothesis, we measured dopamine D2/3 receptor availability with [18F]desmethoxyfallypride-PET (DMFP) in putamen and caudate nucleus (NC) of 21 healthy, right-handed males (24-60 years; 35+/-10). For volumetric analysis, high-resolution T1-weighted MR-images were obtained in 18 of the PET-subjects in order to assess possible age-related decreases in NC and putamen volume. The calculated DMFP binding potentials (BP) showed a right-ward asymmetry in NC of…