Search results for "Negativity"
showing 10 items of 301 documents
Classifying Healthy Children and Children with Attention Deficit through Features Derived from Sparse and Nonnegative Tensor Factorization Using Even…
2010
In this study, we use features extracted by Nonnegative Tensor Factorization (NTF) from event-related potentials (ERPs) to discriminate healthy children and children with attention deficit (AD). The peak amplitude of an ERP has been extensively used to discriminate different groups of subjects for the clinical research. However, such discriminations sometimes fail because the peak amplitude may vary severely with the increased number of subjects and wider range of ages and it can be easily affected by many factors. This study formulates a framework, using NTF to extract features of the evoked brain activities from time-frequency represented ERPs. Through using the estimated features of a ne…
The electron affinity of astatine
2020
One of the most important properties influencing the chemical behavior of an element is the electron affinity (EA). Among the remaining elements with unknown EA is astatine, where one of its isotopes, 211At, is remarkably well suited for targeted radionuclide therapy of cancer. With the At− anion being involved in many aspects of current astatine labeling protocols, the knowledge of the electron affinity of this element is of prime importance. Here we report the measured value of the EA of astatine to be 2.41578(7) eV. This result is compared to state-of-the-art relativistic quantum mechanical calculations that incorporate both the Breit and the quantum electrodynamics (QED) corrections and…
Auditory cortical event-related potentials to pitch deviances in rats
1998
Abstract We recorded epidural event-related potentials (ERPs) from the auditory cortex in anesthetized rats when pitch-deviant tones were presented in a homogenous series of standard tones (oddball condition). Additionally, deviant tones were presented without standard tones (deviant-alone condition). ERPs to deviant tones in the oddball condition differed significantly from ERPs to standard tones at the latency range of 63–243 ms. On the other hand, ERPs to deviant tones in the deviant-alone condition did not differ from ERPs to standard tones until 196 ms from stimulus onset. The results suggest that oddball stimuli can be neurophysiologically discriminated in anesthetized rats. Furthermo…
Distinct neural responses to chord violations: a multiple source analysis study.
2011
The human brain is constantly predicting the auditory environment by representing sequential similarities and extracting temporal regularities. It has been proposed that simple auditory regularities are extracted at lower stations of the auditory cortex and more complex ones at other brain regions, such as the prefrontal cortex. Deviations from auditory regularities elicit a family of early negative electric potentials distributed over the frontal regions of the scalp. In this study, we wished to disentangle the brain processes associated with sequential vs. hierarchical auditory regularities in a musical context by studying the event-related potentials (ERPs), the behavioral responses to v…
Event-related brain responses while listening to entire pieces of music
2017
Brain responses to discrete short sounds have been studied intensively using the event-related potential (ERP) method, in which the electroencephalogram (EEG) signal is divided into epochs time-locked to stimuli of interest. Here we introduce and apply a novel technique which enables one to isolate ERPs in human elicited by continuous music. The ERPs were recorded during listening to a Tango Nuevo piece, a deep techno track and an acoustic lullaby. Acoustic features related to timbre, harmony, and dynamics of the audio signal were computationally extracted from the musical pieces. Negative deflation occurring around 100 milliseconds after the stimulus onset (N100) and positive deflation occ…
Comprehensive auditory discrimination profiles recorded with a fast parametric musical multi-feature mismatch negativity paradigm
2016
Abstract Objective Mismatch negativity (MMN), a component of the auditory event-related potential (ERP) in response to auditory-expectancy violation, is sensitive to central auditory processing deficits associated with several clinical conditions and to auditory skills deriving from musical expertise. This sensitivity is more evident for stimuli integrated in complex sound contexts. This study tested whether increasing magnitudes of deviation (levels) entail increasing MMN amplitude (or decreasing latency), aiming to create a balanced version of the musical multi-feature paradigm towards measurement of extensive auditory discrimination profiles in auditory expertise or deficits. Methods Usi…
Perceiving rhythm where none exists : Event-Related Potential (ERP) correlates of subjective accenting
2008
Previous research suggests that our past experience of rhythmic structure in music results in a tendency for Western listeners to subjectively accent equitonal isochronous sequences. We have shown in an earlier study that the occurrence of a slightly softer tone in the 8th to 11th position of such a sequence evokes a P300 event-related potential (ERP) response of different amplitudes depending on whether the tone occurs in putatively subjectively accented or unaccented sequence positions (Brochard et al., 2003). One current theory of rhythm processing postulates that subjective accenting is the result of predictive modulations of perceptual processes by the attention system. If this is the …
Promises of formal and informal musical activities in advancing neurocognitive development throughout childhood
2015
Adult musicians show superior neural sound discrimination when compared to nonmusicians. However, it is unclear whether these group differences reflect the effects of experience or preexisting neural enhancement in individuals who seek out musical training. Tracking how brain function matures over time in musically trained and nontrained children can shed light on this issue. Here, we review our recent longitudinal event-related potential (ERP) studies that examine how formal musical training and less formal musical activities influence the maturation of brain responses related to sound discrimination and auditory attention. These studies found that musically trained school-aged children an…
Distraction and reorientation in children: A behavioral and ERP study
2004
In the context of distraction, involuntary orienting to task-irrelevant deviations and the following reorienting to task-relevant stimulus information were studied in children aged 5-6 years. In an auditory distraction paradigm, reaction times were prolonged by 51 ms in trials including a task-irrelevant stimulus deviancy. Event-related potentials (ERPs) revealed a mismatch response (MMR) at 252 ms and a reorienting negativity (RON) 476 ms post-stimulus in response to deviating sounds. These behavioral and ERP effects resemble those reported for adults. We conclude that kindergarten children are prone to distraction, although they can quite effectively but not fully shield working memory op…
Event-related brain potentials to change in the frequency and temporal structure of sounds in typically developing 5-6-year-old children.
2015
The brain's ability to recognize different acoustic cues (e.g., frequency changes in rapid temporal succession) is important for speech perception and thus for successful language development. Here we report on distinct event-related potentials (ERPs) in 5-6-year-old children recorded in a passive oddball paradigm to repeated tone pair stimuli with a frequency change in the second tone in the pair, replicating earlier findings. An occasional insertion of a third tone within the tone pair generated a more merged pattern, which has not been reported previously in 5-6-year-old children. Both types of deviations elicited pre-attentive discriminative mismatch negativity (MMN) and late discrimina…