Search results for "ACOUSTIC"
showing 10 items of 1590 documents
Cognitive and Motor Loops of the Human Cerebro-cerebellar System
2010
Abstract We applied fMRI and diffusion-weighted MRI to study the segregation of cognitive and motor functions in the human cerebro-cerebellar system. Our fMRI results show that a load increase in a nonverbal auditory working memory task is associated with enhanced brain activity in the parietal, dorsal premotor, and lateral prefrontal cortices and in lobules VII–VIII of the posterior cerebellum, whereas a sensory-motor control task activated the motor/somatosensory, medial prefrontal, and posterior cingulate cortices and lobules V/VI of the anterior cerebellum. The load-dependent activity in the crus I/II had a specific relationship with cognitive performance: This activity correlated negat…
Spatial resolution of fMRI in the human parasylvian cortex: Comparison of somatosensory and auditory activation
2005
Abstract In spite of its outstanding spatial resolution, the biological resolution of functional MRI may be worse because it depends on the vascular architecture of the brain. Here, we compared the activation patterns of the secondary somatosensory and parietal ventral cortex (SII/PV) with that of the primary auditory cortex and adjacent areas (AI/AII). These two brain regions are located immediately adjacent to each other on opposite banks of the Sylvian fissure, and are anatomically and functionally distinct. In 12 healthy subjects, SII/PV was activated by pneumatic tactile stimuli applied to the index finger (0.5 cm 2 contact area, 4 bar pressure), and AI/AII by amplitude-modulated tones…
Cognitive control after distraction: event-related brain potentials (ERPs) dissociate between different processes of attentional allocation.
2008
Attentional reallocation after a distracting event is an important function of cognitive control. This process is tapped by the reorienting negativity (RON) event-related brain potential. It was argued that the RON reflects orientation of attention to relevant information in working memory. To test this hypothesis participants performed an auditory duration discrimination task. The stimuli were presented in a frequent standard or a rare deviant pitch with deviants resulting in behavioral distraction. Participants accomplished this task under two conditions: In the refocus condition participants were asked to respond to every stimulus; in the reorient condition participants were instructed t…
Why Do Forward Maskers Affect Auditory Intensity Discrimination? Evidence from "Molecular Psychophysics"
2014
Nonsimultaneous maskers can strongly impair performance in an auditory intensity discrimination task. Using methods of molecular psychophysics, we quantified the extent to which (1) a masker-induced impairment of the representation of target intensity (i.e., increase in internal noise) and (2) a systematic influence of the masker intensities on the decision variable contribute to these effects. In a two-interval intensity discrimination procedure, targets were presented in quiet, and combined with forward maskers. The lateralization of the maskers relative to the targets was varied via the interaural time difference. Intensity difference limens (DLs) were strongly elevated under forward mas…
The sound of music: differentiating musicians using a fast, musical multi-feature mismatch negativity paradigm.
2011
Abstract Musicians’ skills in auditory processing depend highly on instrument, performance practice, and on level of expertise. Yet, it is not known though whether the style/genre of music might shape auditory processing in the brains of musicians. Here, we aimed at tackling the role of musical style/genre on modulating neural and behavioral responses to changes in musical features. Using a novel, fast and musical sounding multi-feature paradigm, we measured the mismatch negativity (MMN), a pre-attentive brain response, to six types of musical feature change in musicians playing three distinct styles of music (classical, jazz, rock/pop) and in non-musicians. Jazz and classical musicians sco…
Infant information processing and family history of specific language impairment: converging evidence for RAP deficits from two paradigms
2007
An infant's ability to process auditory signals presented in rapid succession (i.e. rapid auditory processing abilities [RAP]) has been shown to predict differences in language outcomes in toddlers and preschool children. Early deficits in RAP abilities may serve as a behavioral marker for language-based learning disabilities. The purpose of this study is to determine if performance on infant information processing measures designed to tap RAP and global processing skills differ as a function of family history of specific language impairment (SLI) and/or the particular demand characteristics of the paradigm used. Seventeen 6- to 9-month-old infants from families with a history of specific l…
Musical familiarity in congenital amusia: Evidence from a gating paradigm
2013
Congenital amusia has been described as a lifelong deficit of music perception and production, notably including amusic individuals' difficulties to recognize a familiar tune without the aid of lyrics. The present study aimed to evaluate whether amusic individuals might have acquired long-term knowledge of familiar music, and to test for the minimal amount of acoustic information necessary to access this knowledge (if any) in amusia. Segments of familiar and unfamiliar instrumental musical pieces were presented with increasing duration (250, 500, 1000 msec etc.), and participants provided familiarity judgments for each segment. Results showed that amusic individuals succeeded in differentia…
All Talk and No Action: A Transcranial Magnetic Stimulation Study of Motor Cortex Activation during Action Word Production
2004
AbstractA number of researchers have proposed that the premotor and motor areas are critical for the representation of words that refer to actions, but not objects. Recent evidence against this hypothesis indicates that the left premotor cortex is more sensitive to grammatical differences than to conceptual differences between words. However, it may still be the case that other anterior motor regions are engaged in processing a word's sensorimotor features. In the present study, we used singleand paired-pulse transcranial magnetic stimulation to test the hypothesis that left primary motor cortex is activated during the retrieval of words (nouns and verbs) associated with specific actions. W…
Path Following in Non-Visual Conditions.
2018
Path-following tasks have been investigated mostly under visual conditions, that is when subjects are able to see both the path and the tool, or limb, used for navigation. Moreover, only basic path shapes are usually adopted. In the present experiment, participants must rely exclusively on continuous, non-speech, and ecological auditory and vibrotactile cues to follow a path on a flat surface. Two different, asymmetric path shapes were tested. Participants navigated by moving their index finger over a surface sensing position and force. Results show that the different non-visual feedback modes did not affect the task's accuracy, yet they affected its speed, with vibrotactile feedback causin…
Grip force regulates hand impedance to optimize object stability in high impact loads
2011
Anticipatory grip force adjustments are a prime example of the predictive nature of motor control. An object held in precision grip is stabilized by fine adjustments of the grip force against changes in tangential load force arising from inertia during acceleration and deceleration. When an object is subject to sudden impact loads, prediction becomes critical as the time available for sensory feedback is very short. Here, we investigated the control of grip force when participants performed a targeted tapping task with a hand-held object. During the initial transport phase of the movement, load force varied smoothly with acceleration. In contrast, in the collision, load forces sharply incre…