Search results for "lateralization"
showing 10 items of 121 documents
Hemodynamic responses to speech and music in newborn infants
2009
We used near‐infrared spectroscopy (NIRS) to study responses to speech and music on the auditory cortices of 13 healthy full‐term newborn infants during natural sleep. The purpose of the study was to investigate the lateralization of speech and music responses at this stage of development. NIRS data was recorded from eight positions on both hemispheres simultaneously with electroencephalography, electrooculography, electrocardiography, pulse oximetry, and inclinometry. In 11 subjects, statistically significant (P < 0.02) oxygenated (HbO(2)) and total hemoglobin (HbT) responses were recorded. Both stimulus types elicited significant HbO(2) and HbT responses on both hemispheres in five subjec…
1 Hz repetitive transcranial magnetic stimulation of the unaffected hemisphere ameliorates contralesional visuospatial neglect in humans
2002
The aim of the study was to investigate whether low-frequency repetitive transcranial magnetic stimulation (rTMS) over the unaffected hemisphere can ameliorate visuospatial neglect. We treated three right brain damaged patients with left neglect. 900 pulses (1 Hz frequency) were given over left posterior parietal cortex every other day for 2 weeks. Patients performed a computerized task requiring length judgement of prebisected lines, tachistoscopically presented for 150 ms. With respect to rTMS the task was given 15 days before, at the beginning, at the end and 15 days after. At these times patients performed also line bisection and clock drawing tasks. rTMS induced a significant improveme…
The Right Frontopolar Cortex Is Involved in Visual-Spatial Prospective Memory
2013
The involvement of frontopolar cortex in mediating prospective memory processes has been evidenced by various studies, mainly by means of neuroimaging techniques. Recently, one transcranial magnetic stimulation study documented that transient inhibition of left Brodmann Area (BA) 10 impaired verbal prospective memory. This result raises the issue of whether the BA 10 involvement in prospective memory functioning may be modulated by the physical characteristics of the stimuli used. The present study aimed to investigate the role of the frontopolar cortex in visual-spatial PM by means of the application of inhibitory theta-burst stimulation. Twelve volunteers were evaluated after inhibitory t…
Information acquisition in SME's relationship lending and the cost of loans
2015
Abstract This study analyzes the effect of the reputation SMEs get in a relationship lending on the cost of next loans. A unique dataset of 734 Spanish SMEs' relationship lending provides information on a loan-by-loan basis about the ex post previous loan performance, which measures reputation. No prior empirical research differentiates the cost of loans following a defaulted loan from the costs of those following a successfully repaid loan. Results show that lenders obtain information about borrowers' risk-level during relationship lending and use this information. Loans granted after a successful one pledge significantly lower collateral and interest rate than loans granted after a defaul…
P27-S Sex differences and cortical excitability in healthy adolescents
2019
Background Sex is known to influence brain development. However, sex differences in cortical excitability and their relationship to motor functions is unclear. Aim We examined the sex related differences in the degree of handedness, left and right motor cortex excitability and manual dexterity. Methods 28 healthy adolescents (age 16–19 years,19 girls) were studied. The degree of right-handedness was determined by the Waterloo Handedness Questionnaire. Motor threshold (MT) of the abductor pollicis brevis was measured on both hemispheres. Box and block test (BBT) was used for manual dexterity. Independent samples t-test was used in statistical analysis. Results There were no differences betwe…
Auditory and Cognitive Deficits Associated with Acquired Amusia after Stroke: A Magnetoencephalography and Neuropsychological Follow-Up Study
2010
Acquired amusia is a common disorder after damage to the middle cerebral artery (MCA) territory. However, its neurocognitive mechanisms, especially the relative contribution of perceptual and cognitive factors, are still unclear. We studied cognitive and auditory processing in the amusic brain by performing neuropsychological testing as well as magnetoencephalography (MEG) measurements of frequency and duration discrimination using magnetic mismatch negativity (MMNm) recordings. Fifty-three patients with a left (n = 24) or right (n = 29) hemisphere MCA stroke (MRI verified) were investigated 1 week, 3 months, and 6 months after the stroke. Amusia was evaluated using the Montreal Battery of …
Longitudinal 18F-FDG PET and MRI Reveal Evolving Imaging Pathology That Corresponds to Disease Progression in a Patient With ALS-FTD
2019
Single time point positron emission tomography (PET) studies of patients with amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD), have demonstrated hypometabolism or hypermetabolism in certain brain regions. To determine whether longitudinal (at baseline and 20.4 months later) PET and magnetic resonance imaging (MRI) reveal evolving brain imaging pathology corresponding to clinical progression in a patient with ALS-FTD, cerebral glucose metabolic rate, cortical thickness (CT) and cortical area (CA) were obtained and symmetric percent change (SPC) for each calculated. The patient had worsening symptoms and signs of bulbar-onset upper motor neuron-predominant ALS as well as l…
Left but not right temporal involvement in opaque idiom comprehension: a repetitive transcranial magnetic stimulation study
2004
Abstract It has been suggested that figurative language, which includes idioms, is controlled by the right hemisphere. We tested the right hemisphere hypothesis by using repetitive transcranial magnetic stimulation (rTMS) to transiently disrupt the function of the frontal and temporal areas of the right versus left hemisphere in a group of normal participants involved in a task of opaque idiom versus literal sentence comprehension. Forty opaque, nonambiguous idioms were selected. Fifteen young healthy participants underwent rTMS in two sessions. The experiment was run in five blocks, corresponding to the four stimulated scalp positions (left frontal and temporal and right frontal and tempor…
Brain electrical source analysis of primary cortical components of the tibial nerve somatosensory evoked potential using regional sources.
1998
Tibial nerve somatosensory evoked potentials (SEPs) show higher amplitudes ipsilateral to the side of stimulation, whereas subdural recordings revealed a source in the foot area of the contralateral hemisphere. We now investigated this paradoxical lateralization by performing a brain electrical source analysis in the P40 time window (34-46 ms). The tibial nerve was stimulated behind the ankle (8 subjects). On each side, 2048 stimuli were applied twice. SEPs were recorded using 32 magnetic resonance imaging (MRI)-verified electrode positions (bandpass 0.5-500 Hz). In each case, the P40 amplitude was higher ipsilaterally (0.45 +/- 0.14 microV) than contralaterally (-0.49 +/- 0.16 microV). The…
Context-dependent minimisation of prediction errors involves temporal-frontal activation
2020
According to the predictive coding model of perception, the brain constantly generates predictions of the upcoming sensory inputs. Perception is realised through a hierarchical generative model which aims at minimising the discrepancy between predictions and the incoming sensory inputs (i.e., prediction errors). Notably, prediction errors are weighted depending on precision of prior information. However, it remains unclear whether and how the brain monitors prior precision when minimising prediction errors in different contexts. The current study used magnetoencephalography (MEG) to address this question. We presented participants with repetition of two non-predicted probes embedded in cont…