Motor Intention Determines Sensory Attenuation of Brain Responses to Self-initiated Sounds

2014 ◽  
Vol 26 (7) ◽  
pp. 1481-1489 ◽  
Author(s):  
Jana Timm ◽  
Iria SanMiguel ◽  
Julian Keil ◽  
Erich Schröger ◽  
Marc Schönwiesner

One of the functions of the brain is to predict sensory consequences of our own actions. In auditory processing, self-initiated sounds evoke a smaller brain response than passive sound exposure of the same sound sequence. Previous work suggests that this response attenuation reflects a predictive mechanism to differentiate the sensory consequences of one's own actions from other sensory input, which seems to form the basis for the sense of agency (recognizing oneself as the agent of the movement). This study addresses the question whether attenuation of brain responses to self-initiated sounds can be explained by brain activity involved in movement planning rather than movement execution. We recorded ERPs in response to sounds initiated by button presses. In one condition, participants moved a finger to press the button voluntarily, whereas in another condition, we initiated a similar, but involuntary, finger movement by stimulating the corresponding region of the primary motor cortex with TMS. For involuntary movements, no movement intention (and no feeling of agency) could be formed; thus, no motor plans were available to the forward model. A portion of the brain response evoked by the sounds, the N1-P2 complex, was reduced in amplitude following voluntary, self-initiated movements, but not following movements initiated by motor cortex stimulation. Our findings demonstrate that movement intention and the corresponding feeling of agency determine sensory attenuation of brain responses to self-initiated sounds. The present results support the assumptions of a predictive internal forward model account operating before primary motor cortex activation.

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Chuanfu Li ◽  
Jun Yang ◽  
Jinbo Sun ◽  
Chunsheng Xu ◽  
Yuanqiang Zhu ◽  
...  

In recent years, neuroimaging studies of acupuncture have explored extensive aspects of brain responses to acupuncture in finding its underlying mechanisms. Most of these studies have been performed on healthy adults. Only a few studies have been performed on patients with diseases. Brain responses to acupuncture in patients with the same disease at different pathological stages have not been explored, although it may be more important and helpful in uncovering its underlying mechanisms. In the present study, we used fMRI to compare brain responses to acupuncture in patients with Bell’s palsy at different pathological stages with normal controls and found that the brain response to acupuncture varied at different pathological stages of Bell’s palsy. The brain response to acupuncture decreased in the early stages, increased in the later stages, and nearly returned to normal in the recovered group. All of the changes in the brain response to acupuncture could be explained as resulting from the changes in the brain functional status. Therefore, we proposed that the brain response to acupuncture is dependent on the brain functional status, while further investigation is needed to provide more evidence in support of this proposition.


Author(s):  
David Burke

There is extensive machinery at cerebral and spinal levels to support voluntary movement, but spinal mechanisms are often ignored by clinicians and researchers. For movements of the upper and lower limbs, what the brain commands can be modified or even suppressed completely at spinal level. The corticospinal system is the executive pathway for movement arising largely from primary motor cortex, but movement is not initiated there, and other pathways normally contribute to movement. Greater use of these pathways can allow movement to be restored when the corticospinal system is damaged by, e.g. stroke, but there can be unwanted consequences of this ‘plasticity’. There is an extensive literature on cerebral mechanisms in the control of movement, and an equally large literature on spinal reflex function and the changes that occur during movement, and when pathology results in weakness and/or spasticity.


2003 ◽  
Vol 15 (5) ◽  
pp. 683-693 ◽  
Author(s):  
Stefan Koelsch ◽  
Tobias Grossmann ◽  
Thomas C. Gunter ◽  
Anja Hahne ◽  
Erich Schröger ◽  
...  

Numerous studies investigated physiological correlates of the processing of musical information in adults. How these correlates develop during childhood is poorly understood. In the present study, we measured event-related electric brain potentials elicited in 5and 9-year-old children while they listened to (major–minor tonal) music. Stimuli were chord sequences, infrequently containing harmonically inappropriate chords. Our results demonstrate that the degree of (in) appropriateness of the chords modified the brain responses in both groups according to music-theoretical principles. This suggests that already 5-year-old children process music according to a well-established cognitive representation of the major–minor tonal system and according to music-syntactic regularities. Moreover, we show that, in contrast to adults, an early negative brain response was left predominant in boys, whereas it was bilateral in girls, indicating a gender difference in children processing music, and revealing that children process music with a hemispheric weighting different from that of adults. Because children process, in contrast to adults, music in the same hemispheres as they process language, results indicate that children process music and language more similarly than adults. This finding might support the notion of a common origin of music and language in the human brain, and concurs with findings that demonstrate the importance of musical features of speech for the acquisition of language.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Stefan Schaffelhofer ◽  
Hansjörg Scherberger

Grasping requires translating object geometries into appropriate hand shapes. How the brain computes these transformations is currently unclear. We investigated three key areas of the macaque cortical grasping circuit with microelectrode arrays and found cooperative but anatomically separated visual and motor processes. The parietal area AIP operated primarily in a visual mode. Its neuronal population revealed a specialization for shape processing, even for abstract geometries, and processed object features ultimately important for grasping. Premotor area F5 acted as a hub that shared the visual coding of AIP only temporarily and switched to highly dominant motor signals towards movement planning and execution. We visualize these non-discrete premotor signals that drive the primary motor cortex M1 to reflect the movement of the grasping hand. Our results reveal visual and motor features encoded in the grasping circuit and their communication to achieve transformation for grasping.


2019 ◽  
Vol 9 (3) ◽  
pp. 69 ◽  
Author(s):  
Tonya Rich ◽  
Bernadette Gillick

The 10/20 electroencephalogram (EEG) measurements system often guides electrode placement for transcranial direct current stimulation (tDCS), a form of non-invasive brain stimulation. One targeted region of the brain is the primary motor cortex (M1) for motor recovery after stroke, among other clinical indications. M1 is identified by C3 and C4 of the 10/20 EEG system yet the reliability of 10/20 EEG measurements by novice research raters is unknown. We investigated the reliability of the 10/20 EEG measurements for C3 and C4 in 25 adult participants. Two novice raters were assessed for inter-rater reliability. Both raters received two hours of instruction from a registered neurodiagnostic technician. One of the raters completed the measurements across two testing days for intra-rater reliability. Relative reliability was determined using the intraclass coefficient (ICC) and absolute reliability. We observed a low to fair inter and intra-rater ICC for motor cortex measurements. The absolute reliability was <1.0 cm by different novice raters and on different days. Although a low error was observed, consideration of the integrity of the targeted region of the brain is critical when designing tDCS interventions in clinical populations who may have compromised brain structure, due to a lesion or altered anatomy.


Author(s):  
M. S. Chafi ◽  
G. Karami ◽  
M. Ziejewski

In this paper, an integrated numerical approach is introduced to determine the human brain responses when the head is exposed to blast explosions. The procedure is based on a 3D non-linear finite element method (FEM) that implements a simultaneous conduction of explosive detonation, shock wave propagation, and blast-brain interaction of the confronting human head. Due to the fact that there is no reported experimental data on blast-head interactions, several important checkpoints should be made before trusting the brain responses resulting from the blast modeling. These checkpoints include; a) a validated human head FEM subjected to impact loading; b) a validated air-free blast propagation model; and c) the verified blast waves-solid interactions. The simulations presented in this paper satisfy the above-mentioned requirements and checkpoints. The head model employed here has been validated again impact loadings. In this respect, Chafi et al. [1] have examined the head model against the brain intracranial pressure, and brain’s strains under different impact loadings of cadaveric experimental tests of Hardy et al. [2]. In another report, Chafi et al. [3] has examined the air-blast and blast-object simulations using Arbitrary Lagrangian Eulerian (ALE) multi-material and Fluid-Solid Interaction (FSI) formulations. The predicted results of blast propagation matched very well with those of experimental data proving that this computational solid-fluid algorithm is able to accurately predict the blast wave propagation in the medium and the response of the structure to blast loading. Various aspects of blast wave propagations in air as well as when barriers such as solid walls are encountered have been studied. With the head model included, different scenarios have been assumed to capture an appropriate picture of the brain response at a constant stand-off distance of nearly 80cm (2.62 feet) from the explosion core. The impact of brain response due to severity of the blast under different amounts of the explosive material, TNT (0.0838, 0.205, and 0.5lb) is examined. The accuracy of the modeling can provide the information to design protection facilities for human head for the hostile environments.


2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Milan Radoš ◽  
Ines Nikić ◽  
Marko Radoš ◽  
Ivica Kostović ◽  
Patrick Hof ◽  
...  

AbstractIt is known that the brain can compensate for deficits induced by acquired and developmental lesions through functional reorganization of the remaining parenchyma. Arteriovenous malformations (AVM) usually appear prenatally before a functional regional organization of the brain is fully established and patients generally do not present with motor deficits even when the AVM is located in the primary motor area indicating the redistribution of functions in cortical areas that are not pathologically altered. Here we present reorganization of the motor cortex in a patient with a large AVM involving most of the left parietal lobe and the paramedian part of the left precentral gyrus that is responsible for controlling the muscles of the lower limbs. Functional MRI showed that movements of both the right and left feet activated only the primary motor cortex in the right hemisphere, while there was no activation in the left motor cortex. This suggests that complete ipsilateral control over the movements of the right foot had been established in this patient. A reconstruction of the corticospinal tract using diffusion tensor imaging showed a near-complete absence of corticospinal fibers from the part of the left precentral gyrus affected by the AVM. From this clinical presentation it can be concluded that full compensation of motor deficits had occurred by redistributing function to the corresponding motor area of the contralateral


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