scholarly journals Earlier and More Robust Sensorimotor Discrimination of ASL Signs in Deaf Signers During Imitation

2020 ◽  
Author(s):  
Lorna C. Quandt ◽  
A. S. Willis

AbstractBackground: Prior research suggests that the amount of experience an individual has with an action influences the degree to which the sensorimotor systems of their brain are involved in the subsequent perception of those actions. Less is known about how action experience and conceptual understanding impact sensorimotor involvement during imitation. We sought to explore this question by comparing a group of sign language users to a group of non-signers. We pitted the following two hypotheses against each other: 1) Deaf signers will show increased sensorimotor activity during sign imitation, and greater differentiation between sign types, due to greater prior experience and conceptual understanding of the signs; versus 2): Deaf signers will show less sensorimotor system activity and less differentiation of sign types in the sensorimotor system, because for those individuals sign imitation involves language systems of the brain more robustly than sensorimotor systems. We collected electroencephalograms (EEG) while the two groups imitated videos showing one-handed and two-handed ASL signs. Time-frequency data analysis was performed on alpha- and beta-range oscillations while they watched signs with the intent to imitate, and imitated the signs. During observation, deaf signers showed early differentiation in alpha/beta power between the one- and two-handed sign conditions, whereas hearing non-signers did not discriminate between the sign categories this way. Significant differences between groups were seen during sign imitation, wherein deaf signers showed desynchronization of alpha/beta EEG signals, and hearing non-signers showed increased power. The study suggests that in an imitative context, deaf signers engage anticipatory motor preparation in advance of action production, while hearing non-signers engage slower, more memory-related processes to help them complete with the complex task.

2016 ◽  
Vol 115 (4) ◽  
pp. 2224-2236 ◽  
Author(s):  
Yvonne M. Fonken ◽  
Jochem W. Rieger ◽  
Elinor Tzvi ◽  
Nathan E. Crone ◽  
Edward Chang ◽  
...  

Changes in the environment require rapid modification or inhibition of ongoing behavior. We used the stop-signal paradigm and intracranial recordings to investigate response preparation, inhibition, and monitoring of task-relevant information. Electrocorticographic data were recorded in eight patients with electrodes covering frontal, temporal, and parietal cortex, and time-frequency analysis was used to examine power differences in the beta (13–30 Hz) and high-gamma bands (60–180 Hz). Over motor cortex, beta power decreased, and high-gamma power increased during motor preparation for both go trials (Go) and unsuccessful stops (US). For successful stops (SS), beta increased, and high-gamma was reduced, indexing the cancellation of the prepared response. In the middle frontal gyrus (MFG), stop signals elicited a transient high-gamma increase. The MFG response occurred before the estimated stop-signal reaction time but did not distinguish between SS and US trials, likely signaling attention to the salient stop stimulus. A postresponse high-gamma increase in MFG was stronger for US compared with SS and absent in Go, supporting a role in behavior monitoring. These results provide evidence for differential contributions of frontal subregions to response inhibition, including motor preparation and inhibitory control in motor cortex and cognitive control and action evaluation in lateral prefrontal cortex.


2019 ◽  
Author(s):  
Emily Kubicek ◽  
Lorna Quandt

ABSTRACTWhen a person observes someone else performing an action, the observer’s sensorimotor cortex activates as if the observer is the one performing the action, a phenomenon known as action simulation. While this process has been well-established for basic (e.g. grasping) and complex (e.g. dancing) actions, it remains unknown if the framework of action simulation is applicable to visual languages such as American Sign Language (ASL). We conducted an EEG experiment with deaf signers and hearing non-signers to compare overall sensorimotor EEG between groups, and to test whether sensorimotor systems are differentially sensitive to signs that are produced with one hand (“1H”) or two hands (“2H”). We predicted greater alpha and beta event-related desynchronization (previously correlated with action simulation) during the perception of 2H ASL signs compared to 1H ASL signs, due to greater demands on sensorimotor processing systems required for producing two-handed actions. We recorded EEG from both groups as they observed videos of ASL signs, half 1H and half 2H. Event-related spectral perturbations (ERSPs) in the alpha and beta ranges were computed for the two conditions at central electrode sites overlying the sensorimotor cortex. Sensorimotor EEG responses in both Hearing and Deaf groups were sensitive to the observed gross motor characteristics of the observed signs. We show for the first time that despite hearing non-signers showing overall more sensorimotor cortex involvement during sign observation, mirroring-related processes are in fact involved when deaf signers observe signs.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3929
Author(s):  
Han-Yun Chen ◽  
Ching-Hung Lee

This study discusses convolutional neural networks (CNNs) for vibration signals analysis, including applications in machining surface roughness estimation, bearing faults diagnosis, and tool wear detection. The one-dimensional CNNs (1DCNN) and two-dimensional CNNs (2DCNN) are applied for regression and classification applications using different types of inputs, e.g., raw signals, and time-frequency spectra images by short time Fourier transform. In the application of regression and the estimation of machining surface roughness, the 1DCNN is utilized and the corresponding CNN structure (hyper parameters) optimization is proposed by using uniform experimental design (UED), neural network, multiple regression, and particle swarm optimization. It demonstrates the effectiveness of the proposed approach to obtain a structure with better performance. In applications of classification, bearing faults and tool wear classification are carried out by vibration signals analysis and CNN. Finally, the experimental results are shown to demonstrate the effectiveness and performance of our approach.


2021 ◽  
Vol 153 ◽  
pp. 107755
Author(s):  
Benjamin J. Griffiths ◽  
María Carmen Martín-Buro ◽  
Bernhard P. Staresina ◽  
Simon Hanslmayr ◽  
Tobias Staudigl

2019 ◽  
Author(s):  
Benjamin J. Griffiths ◽  
Stephen D. Mayhew ◽  
Karen J. Mullinger ◽  
João Jorge ◽  
Ian Charest ◽  
...  

AbstractMassed synchronised neuronal firing is detrimental to information processing. When networks of task-irrelevant neurons fire in unison, they mask the signal generated by task-critical neurons. On a macroscopic level, mass synchronisation of these neurons can contribute to the ubiquitous alpha/beta (8-30Hz) oscillations. Reductions in the amplitude of these oscillations, therefore, may reflect a boost in the processing of high-fidelity information within the cortex. Here, we test this hypothesis. Twenty-one participants completed an associative memory task while undergoing simultaneous EEG-fMRI recordings. Using representational similarity analysis, we quantified the amount of stimulus-specific information represented within the BOLD signal on every trial. When correlating this metric with concurrently-recorded alpha/beta power, we found a significant negative correlation which indicated that as alpha/beta power decreased, our metric of stimulus-specific information increased. This effect generalised across cognitive tasks, as the negative relationship could be observed during visual perception and episodic memory retrieval. Further analysis revealed that this effect could be better explained by alpha/beta power decreases providing favourable conditions for information processing, rather than directly representing stimulus-specific information. Together, these results indicate that alpha/beta power decreases parametrically track the fidelity of both externally-presented and internally-generated stimulus-specific information represented within the cortex.


2017 ◽  
Vol 26 (2) ◽  
pp. 132-139 ◽  
Author(s):  
Iris Berent

Why do humans drink and drive but fail to rdink and rdive? Here, I suggest that these regularities could reflect abstract phonological principles that are active in the minds and brains of all speakers. In support of this hypothesis, I show that (a) people converge on the same phonological preferences (e.g., dra over rda) even when the relevant structures (e.g., dra, rda) are unattested in their language and that (b) such behavior is inexplicable by purely sensorimotor pressures or experience with similar syllables. Further support for the distinction between phonology and the sensorimotor system is presented by their dissociation in dyslexia, on the one hand, and the transfer of phonological knowledge from speech to sign, on the other. A detailed analysis of the phonological system can elucidate the functional architecture of the typical mind/brain and the etiology of speech and language disorders.


2020 ◽  
Author(s):  
David Schubring ◽  
Harald T Schupp

Abstract The study of brain oscillations associated with emotional picture processing has revealed conflicting findings. Although many studies observed a decrease in power in the alpha- and lower beta band, some studies observed an increase. Accordingly, the main aim of the present research series was to further elucidate whether emotional stimulus processing is related to an increase or decrease in alpha/beta power. In Study 1, participants (N = 16) viewed briefly presented (150 ms) high-arousing erotic and low-arousing people pictures. Picture presentation included a passive viewing condition and an active picture categorization task. Study 2 (N = 16) replicated Study 1 with negative valence stimuli (mutilations). In Study 3 (N = 18), stimulus materials of Study 1 and 2 were used. The main finding is that high-arousing pictures (erotica and mutilations) are associated with a decrease of power in the alpha/beta band across studies and task conditions. The effect peaked in occipitoparietal sensors between 400 and 800 ms after stimulus onset. Furthermore, a late (>1000 ms) alpha/beta power increase to mutilation pictures was observed, possibly reflecting top–down inhibitory control processes. Overall, these findings suggest that brain oscillations in the alpha/beta-band may serve as a useful measure of emotional stimulus processing.


2010 ◽  
Vol 22 (7) ◽  
pp. 1333-1347 ◽  
Author(s):  
Marcel Bastiaansen ◽  
Lilla Magyari ◽  
Peter Hagoort

There is growing evidence suggesting that synchronization changes in the oscillatory neuronal dynamics in the EEG or MEG reflect the transient coupling and uncoupling of functional networks related to different aspects of language comprehension. In this work, we examine how sentence-level syntactic unification operations are reflected in the oscillatory dynamics of the MEG. Participants read sentences that were either correct, contained a word category violation, or were constituted of random word sequences devoid of syntactic structure. A time–frequency analysis of MEG power changes revealed three types of effects. The first type of effect was related to the detection of a (word category) violation in a syntactically structured sentence, and was found in the alpha and gamma frequency bands. A second type of effect was maximally sensitive to the syntactic manipulations: A linear increase in beta power across the sentence was present for correct sentences, was disrupted upon the occurrence of a word category violation, and was absent in syntactically unstructured random word sequences. We therefore relate this effect to syntactic unification operations. Thirdly, we observed a linear increase in theta power across the sentence for all syntactically structured sentences. The effects are tentatively related to the building of a working memory trace of the linguistic input. In conclusion, the data seem to suggest that syntactic unification is reflected by neuronal synchronization in the lower-beta frequency band.


2004 ◽  
Vol 84 (2) ◽  
pp. 385-410 ◽  
Author(s):  
STEPHEN J. LAI-FOOK

Lai-Fook, Stephen J. Pleural Mechanics and Fluid Exchange. Physiol Rev 84: 385–410, 2004; 10.1152/physrev.00026.2003.—The pleural space separating the lung and chest wall of mammals contains a small amount of liquid that lubricates the pleural surfaces during breathing. Recent studies have pointed to a conceptual understanding of the pleural space that is different from the one advocated some 30 years ago in this journal (Agostoni E. Physiol Rev 52: 57–128, 1972). The fundamental concept is that pleural surface pressure, the result of the opposing recoils of the lung and chest wall, is the major determinant of the pressure in the pleural liquid. Pleural liquid is not in hydrostatic equilibrium because the vertical gradient in pleural liquid pressure, determined by the vertical gradient in pleural surface pressure, does not equal the hydrostatic gradient. As a result, a viscous flow of pleural liquid occurs in the pleural space. Ventilatory and cardiogenic motions serve to redistribute pleural liquid and minimize contact between the pleural surfaces. Pleural liquid is a microvascular filtrate from parietal pleural capillaries in the chest wall. Homeostasis in pleural liquid volume is achieved by an adjustment of the pleural liquid thickness to the filtration rate that is matched by an outflow via lymphatic stomata.


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