scholarly journals Functional and Neural Mechanisms of Out-of-Body Experiences: Importance of Retinogeniculo-Cortical Oscillations

2016 ◽  
Vol 06 (04) ◽  
pp. 287-302 ◽  
Author(s):  
Ravinder Jerath ◽  
Shannon M. Cearley ◽  
Vernon A. Barnes ◽  
Mike Jensen
2013 ◽  
Vol 109 (12) ◽  
pp. 3082-3093 ◽  
Author(s):  
Cort Horton ◽  
Michael D'Zmura ◽  
Ramesh Srinivasan

People are highly skilled at attending to one speaker in the presence of competitors, but the neural mechanisms supporting this remain unclear. Recent studies have argued that the auditory system enhances the gain of a speech stream relative to competitors by entraining (or “phase-locking”) to the rhythmic structure in its acoustic envelope, thus ensuring that syllables arrive during periods of high neuronal excitability. We hypothesized that such a mechanism could also suppress a competing speech stream by ensuring that syllables arrive during periods of low neuronal excitability. To test this, we analyzed high-density EEG recorded from human adults while they attended to one of two competing, naturalistic speech streams. By calculating the cross-correlation between the EEG channels and the speech envelopes, we found evidence of entrainment to the attended speech's acoustic envelope as well as weaker yet significant entrainment to the unattended speech's envelope. An independent component analysis (ICA) decomposition of the data revealed sources in the posterior temporal cortices that displayed robust correlations to both the attended and unattended envelopes. Critically, in these components the signs of the correlations when attended were opposite those when unattended, consistent with the hypothesized entrainment-based suppressive mechanism.


2021 ◽  
Author(s):  
Daniel J. Cameron ◽  
Jessica A. Grahn

AbstractPerception of a regular beat is essential to our ability to synchronize movements to music in an anticipatory fashion. Beat perception requires multiple, distinct neural functions, corresponding to the perceptual stages that occur over time, including 1) detection that regularity is present (beat finding), 2) prediction of future regular events to enable anticipation (beat continuation), and 3) dynamic adjustment of predictions as the rhythmic stimulus changes (beat adjustment). The striatum has been shown to be crucial for beat perception generally, although it is unclear how, or whether, distinct regions of the striatum contribute to these different stages of beat perception. Here, we used fMRI to investigate the activity of striatal subregions during the different stages of beat perception. Participants listened to pairs of rhythms (polyrhythms) whose temporal structure induced distinct perceptual stages—finding, continuation, and adjustment of the beat. Dorsal putamen was preferentially active during beat finding, whereas the ventral putamen was preferentially active during beat adjustment. We also observed that anterior insula activity was sensitive to metrical structure (greater when polyrhythms were metrically incongruent than when they were congruent). These data implicate the dorsal putamen in the detection of regularity, possibly by detection of coincidences between cortical oscillations, and the ventral putamen in the adjustment of regularity perception, possibly by integration of prediction errors in ongoing beat predictions. Additionally, activity in the supramarginal and superior temporal gyri correlated with beat tapping performance, and activity in the superior temporal gyrus correlated with beat perception (performance on the Beat Alignment Test).


2015 ◽  
Vol 15 (1-2) ◽  
pp. 13-31 ◽  
Author(s):  
Pieter F. Craffert

In recent years there has been an increased interest in the study of out-of-body experiences (obes) by cognitive and neuro-scientists. Nowadays, far-reaching claims regarding the uncovering of the neural mechanisms and pathways, as well as the mystery ofobes in the anthropological and historical record are on offer. In this article the implicit assumption thatobes are much better understood and that real progress has been made are questioned on the basis of the definitional and conceptual problems that still haunt this area of research. It is suggested that progress will only be registered once the spectrum of out-of-body phenomena (obp) is recognized and attention is paid to the neurocultural complexity of distinct instances ofobes.


2014 ◽  
Author(s):  
Jennifer T. Kubota ◽  
Tobias Brosch ◽  
Rachel Mojdehbakhsh ◽  
James S. Uleman ◽  
Elizabeth Phelps
Keyword(s):  

2011 ◽  
Author(s):  
Wouter van den Bos ◽  
Arjun Talwar ◽  
Samuel McClure

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