Neural Responses to Melodic and Harmonic Closure: An Event-Related-Potential Study

1997 ◽  
Vol 15 (1) ◽  
pp. 69-98 ◽  
Author(s):  
Edwin C. Hantz ◽  
Kelley G. Kreilick ◽  
William Kananen ◽  
Kenneth P. Swartz

The event-related evoked potential (ERP) responses to sentence endings that either confirm or violate syntactic/semantic constraints have been extensively studied. Very little is known, however, about the corresponding situation with respect to music. The current study investigates the brain- wave (ERP) responses to perceived phrase closure. ERPs are a potentially valid measure of how language-like or uniquely musical the perception of phrase closure is. In our study, highly trained musicians (N= 16) judged whether or not novel musical phrases were closed (melodically or harmonically). Three stimulus series consisted of seven- note tunes with four possible endings: closed (tonic note or tonic chord), open/ diatonic (dominant chord or a member thereof), open/ chromatic (a chromatic note or chord outside the key of the melody), or open/white noise (a nonmusical control). One series included melodies alone, a second series included melodies harmonized, and a third series included melodies in which the melodic contexts were disrupted rather than the endings. In the recorded ERPs, a statistically significant negative drift in the waveforms occurred over the course of the context series, indicating anticipation of closure. The drift-corrected poststimulus waveforms for all series were subjected to a principal components analysis/analysis of variance. Two subject variables were also considered: sex and absolute pitch. All four stimulus types elicited identifiable responses. The waveform peaks for the four stimulus types are clearly differentiated by principal component analysis scores to two components: one with a maximum value at 273 ms and one with a maximum value at 471 ms. Taking the closed endings as the expected "standard," the waveforms for the two types of musical deviant endings were significantly below the standard at 273 ms and above the standard at 471 ms. The amount of negativity was proportional to the amount of deviance of the ending. The positive peak in the closed condition and the reduced peak in the open/diatonic condition are contrary to the normal inverse relationship between peak size and stimulus probability; the former agrees with peaks found in response to syntactic closure in language. Significant, though isolated, interactions involving both sex and absolute pitch also emerged.

2003 ◽  
Vol 20 (4) ◽  
pp. 357-382 ◽  
Author(s):  
Laura Bischoff Renninger ◽  
Roni I. Granot ◽  
Emanuel Donchin

Our primary goal has been to elucidate a model of pitch memory by examining the brain activity of musicians with and without absolute pitch during listening tasks. Subjects, screened for both absolute and relative pitch abilities, were presented with two auditory tasks and one visual task that served as a control. In the first auditory task (pitch memory task), subjects were asked to differentiate between diatonic and nondiatonic tones within a tonal framework. In the second auditory task (contour task), subjects were presented with the same pitch sequences but instead asked to differentiate between tones moving upward or downward. For the visual control task, subjects were presented again with the same pitch sequences and asked to determine whether each pitch was diatonic or nondiatonic, only this time the note names appeared visually on the computer screen. Our findings strongly suggest that there are various levels of absolute pitch ability. Some absolute pitch subjects have, in addition to this skill, strong relative pitch abilities, and these differences are reflected quite consistently by the behavior of the P300 component of the event-related potential. Our research also strengthens the idea that the memory system for pitch and interval distances is distinct from the memory system for contour (W. J. Dowling, 1978). Our results are discussed within the context of the current absolute pitch literature.


2001 ◽  
Vol 13 (7) ◽  
pp. 1019-1034 ◽  
Author(s):  
Bruno Rossion ◽  
Christine Schiltz ◽  
Laurence Robaye ◽  
David Pirenne ◽  
Marc Crommelinck

Where and how does the brain discriminate familiar and unfamiliar faces? This question has not been answered yet by neuroimaging studies partly because different tasks were performed on familiar and unfamiliar faces, or because familiar faces were associated with semantic and lexical information. Here eight subjects were trained during 3 days with a set of 30 faces. The familiarized faces were morphed with unfamiliar faces. Presented with continua of unfamiliar and familiar faces in a pilot experiment, a group of eight subjects presented a categorical perception of face familiarity: there was a sharp boundary in percentage of familiarity decisions between 40% and 60% faces. In the main experiment, subjects were scanned (PET) on the fourth day (after 3 days of training) in six conditions, all requiring a sex classification task. Completely novel faces (0%) were presented in Condition 1 and familiar faces (100%) in Condition 6, while faces of steps of 20% in the continuum of familiarity were presented in Conditions 2 to 5 (20% to 80%). A principal component analysis (PCA) indicated that most variations in neural responses were related to the dissociation between faces perceived as familiar (60% to 100%) and faces perceived as unfamiliar (0 to 40%). Subtraction analyses did not disclose any increase of activation for faces perceived as familiar while there were large relative increases for faces perceived as unfamiliar in several regions of the right occipito-temporal visual pathway. These changes were all categorical and were observed mainly in the right middle occipital gyrus, the right posterior fusiform gyrus, and the right inferotemporal cortex. These results show that (1) the discrimination between familiar and unfamiliar faces is related to relative increases in the right ventral pathway to unfamiliar/novel faces; (2) familiar and unfamiliar faces are discriminated in an all-or-none fashion rather than proportionally to their resemblance to stored representations; and (3) categorical perception of faces is associated with abrupt changes of brain activity in the regions that discriminate the two extremes of the multidimensional continuum.


2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Muhammad Naeem ◽  
Clemens Brunner ◽  
Gert Pfurtscheller

The performance of spatial filters based on independent components analysis (ICA) was evaluated by employing principal component analysis (PCA) preprocessing for dimensional reduction. The PCA preprocessing was not found to be a suitable method that could retain motor imagery information in a smaller set of components. In contrast, 6 ICA components selected on the basis of visual inspection performed comparably (61.9%) to the full range of 22 components (63.9%). An automated selection of ICA components based on a variance criterion was also carried out. Only 8 components chosen this way performed better (63.1%) than visually selected components. A similar analysis on the reduced set of electrodes over mid-central and centro-parietal regions of the brain revealed that common spatial patterns (CSPs) and Infomax were able to detect motor imagery activity with a satisfactory accuracy.


Author(s):  
Hamid Karimi-Rouzbahani ◽  
Mozhgan Shahmohammadi ◽  
Ehsan Vahab ◽  
Saeed Setayeshi ◽  
Thomas Carlson

AbstractHumans are remarkably efficent at recognizing objects. Understanding how the brain performs object recognition has been challenging. Our understanding has been advanced substantially in recent years with the development of multivariate decoding methods. Most start-of-the-art decoding procedures, make use of the ‘mean’ neural activation to extract object category information, which overlooks temporal variability in the signals. Here, we studied category-related information in 30 mathematically distinct features from electroencephalography (EEG) across three independent and highly-varied datasets using multivariate decoding. While the event-related potential (ERP) components of N1 and P2a were among the most informative features, the informative original signal samples and Wavelet coefficients, selected through principal component analysis, outperformed them. The four mentioned informative features showed more pronounced decoding in the Theta frequency band, which has been suggested to support feed-forward processing of visual information in the brain. Correlational analyses showed that the features, which were most informative about object categories, could predict participants’ behavioral performance (reaction time) more accurately than the less informative features. These results suggest a new approach for studying how the human brain encodes object category information and how we can read them out more optimally to investigate the temporal dynamics of the neural code. The codes are available online at https://osf.io/wbvpn/.


Author(s):  
Sally M. Essawy ◽  
Basil Kamel ◽  
Mohamed S. Elsawy

Some buildings hold certain qualities of space design similar to those originated from nature in harmony with its surroundings. These buildings, mostly associated with religious beliefs and practices, allow for human comfort and a unique state of mind. This paper aims to verify such effect on the human brain. It concentrates on measuring brain waves when the user is located in several spots (coordinates) in some of these buildings. Several experiments are conducted on selected case studies to identify whether certain buildings affect the brain wave frequencies of their users or not. These are measured in terms of Brain Wave Frequency Charts through EEG Device. The changes identified on the brain were then translated into a brain diagram that reflects the spiritual experience all through the trip inside the selected buildings. This could then be used in architecture to enhance such unique quality.


2020 ◽  
Author(s):  
Fernando Ferreira-Santos ◽  
Mariana R. Pereira ◽  
Tiago O. Paiva ◽  
Pedro R. Almeida ◽  
Eva C. Martins ◽  
...  

The behavioral and electrophysiological study of the emotional intensity of facial expressions of emotions has relied on image processing techniques termed ‘morphing’ to generate realistic facial stimuli in which emotional intensity can be manipulated. This is achieved by blending neutral and emotional facial displays and treating the percent of morphing between the two stimuli as an objective measure of emotional intensity. Here we argue that the percentage of morphing between stimuli does not provide an objective measure of emotional intensity and present supporting evidence from affective ratings and neural (event-related potential) responses. We show that 50% morphs created from high or moderate arousal stimuli differ in subjective and neural responses in a sensible way: 50% morphs are perceived as having approximately half of the emotional intensity of the original stimuli, but if the original stimuli differed in emotional intensity to begin with, then so will the morphs. We suggest a re-examination of previous studies that used percentage of morphing as a measure of emotional intensity and highlight the value of more careful experimental control of emotional stimuli and inclusion of proper manipulation checks.


Author(s):  
Pooja Prabhu ◽  
A. K. Karunakar ◽  
Sanjib Sinha ◽  
N. Mariyappa ◽  
G. K. Bhargava ◽  
...  

AbstractIn a general scenario, the brain images acquired from magnetic resonance imaging (MRI) may experience tilt, distorting brain MR images. The tilt experienced by the brain MR images may result in misalignment during image registration for medical applications. Manually correcting (or estimating) the tilt on a large scale is time-consuming, expensive, and needs brain anatomy expertise. Thus, there is a need for an automatic way of performing tilt correction in three orthogonal directions (X, Y, Z). The proposed work aims to correct the tilt automatically by measuring the pitch angle, yaw angle, and roll angle in X-axis, Z-axis, and Y-axis, respectively. For correction of the tilt around the Z-axis (pointing to the superior direction), image processing techniques, principal component analysis, and similarity measures are used. Also, for correction of the tilt around the X-axis (pointing to the right direction), morphological operations, and tilt correction around the Y-axis (pointing to the anterior direction), orthogonal regression is used. The proposed approach was applied to adjust the tilt observed in the T1- and T2-weighted MR images. The simulation study with the proposed algorithm yielded an error of 0.40 ± 0.09°, and it outperformed the other existing studies. The tilt angle (in degrees) obtained is ranged from 6.2 ± 3.94, 2.35 ± 2.61, and 5 ± 4.36 in X-, Z-, and Y-directions, respectively, by using the proposed algorithm. The proposed work corrects the tilt more accurately and robustly when compared with existing studies.


2021 ◽  
pp. 000370282098784
Author(s):  
James Renwick Beattie ◽  
Francis Esmonde-White

Spectroscopy rapidly captures a large amount of data that is not directly interpretable. Principal Components Analysis (PCA) is widely used to simplify complex spectral datasets into comprehensible information by identifying recurring patterns in the data with minimal loss of information. The linear algebra underpinning PCA is not well understood by many applied analytical scientists and spectroscopists who use PCA. The meaning of features identified through PCA are often unclear. This manuscript traces the journey of the spectra themselves through the operations behind PCA, with each step illustrated by simulated spectra. PCA relies solely on the information within the spectra, consequently the mathematical model is dependent on the nature of the data itself. The direct links between model and spectra allow concrete spectroscopic explanation of PCA, such the scores representing ‘concentration’ or ‘weights’. The principal components (loadings) are by definition hidden, repeated and uncorrelated spectral shapes that linearly combine to generate the observed spectra. They can be visualized as subtraction spectra between extreme differences within the dataset. Each PC is shown to be a successive refinement of the estimated spectra, improving the fit between PC reconstructed data and the original data. Understanding the data-led development of a PCA model shows how to interpret application specific chemical meaning of the PCA loadings and how to analyze scores. A critical benefit of PCA is its simplicity and the succinctness of its description of a dataset, making it powerful and flexible.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 585
Author(s):  
Alexander Burren ◽  
Constanze Pietsch

In this study, a stress trial was conducted with common carp, one of the most important species in aquaculture worldwide, to identify relevant gene regulation pathways in different areas of the brain. Acute distress due to exposure to air significantly activated the expression of the immediate early gene c-fos in the telencephalon. In addition, evidence for regulation of the two corticotropin-releasing factor (crf) genes in relation to their binding protein (corticotropin-releasing hormone-binding protein, crh-bp) is presented in this preliminary study. Inferences on the effects of due to exposure to air were obtained by using point estimation, which allows the prediction of a single value. This constitutes the best description to date of the previously generally unknown effects of stress in different brain regions in carp. Furthermore, principal component analyses were performed to reveal possible regulation patterns in the different regions of the fish brain. In conclusion, these preliminary studies on gene regulation in the carp brain that has been influenced by exposure to a stressor reveal that a number of genes may be successfully used as markers for exposure to unfavourable conditions.


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