scholarly journals Pubertal Testosterone Tracks the Developmental Trajectory of Neural Oscillatory Activity Serving Visuospatial Processing

2020 ◽  
Vol 30 (11) ◽  
pp. 5960-5971 ◽  
Author(s):  
Madison H Fung ◽  
Brittany K Taylor ◽  
Michaela R Frenzel ◽  
Jacob A Eastman ◽  
Yu-Ping Wang ◽  
...  

Abstract Puberty is a period of substantial hormonal fluctuations that induce dramatic physical, neurological, and behavioral changes. Previous research has demonstrated that pubertal hormones modulate cortical development, as well as sex- and age-specific patterns of cognitive development during childhood and adolescence. However, the influence of pubertal hormones on the brain’s functional development, specifically neural oscillatory dynamics, has yet to be fully examined. Thus, in the current study, we used magnetoencephalography to investigate the oscillatory dynamics serving visuospatial perception and attention, and testosterone levels and chronological age as measures of development. Within a sample of typically developing youth, age was associated with changes in alpha, theta, and gamma oscillatory activity. Novel testosterone-by-sex interactions in the gamma range were identified in critical areas of the visual and attention networks. Females had increased gamma activity with increasing testosterone in the right temporal-parietal junction and occipital cortices, while males showed increased gamma activity in the right insula with increasing testosterone. These findings reveal robust developmental alterations in the oscillatory dynamics serving visuospatial processing during childhood and adolescence and provide novel insight into the hormonal basis of sexually dimorphic patterns of functional brain development during the pubertal transition that is at least partially mediated by endogenous testosterone.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jelena Trajkovic ◽  
Francesco Di Gregorio ◽  
Francesca Ferri ◽  
Chiara Marzi ◽  
Stefano Diciotti ◽  
...  

AbstractSchizophrenia is among the most debilitating neuropsychiatric disorders. However, clear neurophysiological markers that would identify at-risk individuals represent still an unknown. The aim of this study was to investigate possible alterations in the resting alpha oscillatory activity in normal population high on schizotypy trait, a physiological condition known to be severely altered in patients with schizophrenia. Direct comparison of resting-state EEG oscillatory activity between Low and High Schizotypy Group (LSG and HSG) has revealed a clear right hemisphere alteration in alpha activity of the HSG. Specifically, HSG shows a significant slowing down of right hemisphere posterior alpha frequency and an altered distribution of its amplitude, with a tendency towards a reduction in the right hemisphere in comparison to LSG. Furthermore, altered and reduced connectivity in the right fronto-parietal network within the alpha range was found in the HSG. Crucially, a trained pattern classifier based on these indices of alpha activity was able to successfully differentiate HSG from LSG on tested participants further confirming the specific importance of right hemispheric alpha activity and intrahemispheric functional connectivity. By combining alpha activity and connectivity measures with a machine learning predictive model optimized in a nested stratified cross-validation loop, current research offers a promising clinical tool able to identify individuals at-risk of developing psychosis (i.e., high schizotypy individuals).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chloé Stengel ◽  
Marine Vernet ◽  
Julià L. Amengual ◽  
Antoni Valero-Cabré

AbstractCorrelational evidence in non-human primates has reported increases of fronto-parietal high-beta (22–30 Hz) synchrony during the top-down allocation of visuo-spatial attention. But may inter-regional synchronization at this specific frequency band provide a causal mechanism by which top-down attentional processes facilitate conscious visual perception? To address this question, we analyzed electroencephalographic (EEG) signals from a group of healthy participants who performed a conscious visual detection task while we delivered brief (4 pulses) rhythmic (30 Hz) or random bursts of Transcranial Magnetic Stimulation (TMS) to the right Frontal Eye Field (FEF) prior to the onset of a lateralized target. We report increases of inter-regional synchronization in the high-beta band (25–35 Hz) between the electrode closest to the stimulated region (the right FEF) and right parietal EEG leads, and increases of local inter-trial coherence within the same frequency band over bilateral parietal EEG contacts, both driven by rhythmic but not random TMS patterns. Such increases were accompained by improvements of conscious visual sensitivity for left visual targets in the rhythmic but not the random TMS condition. These outcomes suggest that high-beta inter-regional synchrony can be modulated non-invasively and that high-beta oscillatory activity across the right dorsal fronto-parietal network may contribute to the facilitation of conscious visual perception. Our work supports future applications of non-invasive brain stimulation to restore impaired visually-guided behaviors by operating on top-down attentional modulatory mechanisms.


2012 ◽  
Vol 24 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Frank Oppermann ◽  
Uwe Hassler ◽  
Jörg D. Jescheniak ◽  
Thomas Gruber

The human cognitive system is highly efficient in extracting information from our visual environment. This efficiency is based on acquired knowledge that guides our attention toward relevant events and promotes the recognition of individual objects as they appear in visual scenes. The experience-based representation of such knowledge contains not only information about the individual objects but also about relations between them, such as the typical context in which individual objects co-occur. The present EEG study aimed at exploring the availability of such relational knowledge in the time course of visual scene processing, using oscillatory evoked gamma-band responses as a neural correlate for a currently activated cortical stimulus representation. Participants decided whether two simultaneously presented objects were conceptually coherent (e.g., mouse–cheese) or not (e.g., crown–mushroom). We obtained increased evoked gamma-band responses for coherent scenes compared with incoherent scenes beginning as early as 70 msec after stimulus onset within a distributed cortical network, including the right temporal, the right frontal, and the bilateral occipital cortex. This finding provides empirical evidence for the functional importance of evoked oscillatory activity in high-level vision beyond the visual cortex and, thus, gives new insights into the functional relevance of neuronal interactions. It also indicates the very early availability of experience-based knowledge that might be regarded as a fundamental mechanism for the rapid extraction of the gist of a scene.


Author(s):  
Asawari Deshpande ◽  
Shashikala Gurpur ◽  
Sujata Arya ◽  
Shireshi Shambhulinganand

The 2020 Amendment Act, of Medical Termination of Pregnancy has reinvigorated the discussion with regards to bodily autonomy and reproductive rights in India. This comes at a juncture of time, where the discussion regarding reproductive rights is an important part of the global socio-political narrative. The aim of this paper is to study the developmental trajectory of reproductive rights by gauging how the right to abortion has fared in various countries across the world by analysing specific legislations, judicial precedents and statistical data. We examine how one may secure the reproductive health rights of a woman better by analysing the two functional methods adopted thus far - either through liberal legislations that guarantee full autonomy to the woman or more restrictive laws that permit abortions only in certain circumstances - a major. The second half of this paper focuses on India, a country whose culture is traditionally perceived to be deeply rooted in orthodoxy and conservatives. The Medical Termination of Pregnancy Act was enacted in 1971, and the 2020 Amendment has garnered acclaim for its more progressive outlook and direction. Even though the amendment has addressed some of the major concerns voiced out by reproductive rights’ activists, there are still a few systemic and practical dogmas that are still pervasive in the reproductive rights domain. The paper discusses these prevalent lacunae at play at length and emphasizes on the need for comprehensive and quick solutions. These will contribute to the prevention of unwanted pregnancies while simultaneously reducing the physical and psychological harm that is caused to vulnerable women across the country.


2019 ◽  
Author(s):  
S. A. Herff ◽  
C. Herff ◽  
A. J. Milne ◽  
G. D. Johnson ◽  
J. J. Shih ◽  
...  

AbstractRhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope-tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners, to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in the musical rhythms, we compute the correlation between the autocorrelations (ACC) of both the musical rhythms and the neural signals. A condition in which participants listened to white noise was used to establish a baseline. High-gamma autocorrelations in auditory areas in the superior temporal gyrus and in frontal areas on both hemispheres significantly matched the autocorrelation of the musical rhythms. Overall, numerous significant electrodes are observed on the right hemisphere. Of particular interest is a large cluster of electrodes in the right prefrontal cortex that is active during both rhythm perception and imagination. This indicates conscious processing of the rhythms’ structure as opposed to mere auditory phenomena. The ACC approach clearly highlights that high-gamma activity measured from cortical electrodes tracks both attended and imagined rhythms.


2010 ◽  
Vol 103 (3) ◽  
pp. 1658-1672 ◽  
Author(s):  
Tobias Kalenscher ◽  
Carien S. Lansink ◽  
Jan V. Lankelma ◽  
Cyriel M. A. Pennartz

Oscillations of local field potentials (LFPs) in the gamma range are found in many brain regions and are supposed to support the temporal organization of cognitive, perceptual, and motor functions. Even though gamma oscillations have also been observed in ventral striatum, one of the brain's most important structures for motivated behavior and reward processing, their specific function during ongoing behavior is unknown. Using a movable tetrode array, we recorded LFPs and activity of neural ensembles in the ventral striatum of rats performing a reward-collection task. Rats were running along a triangle track and in each round collected one of three different types of rewards. The gamma power of LFPs on subsets of tetrodes was modulated by reward-site visits, discriminated between reward types, between baitedness of reward locations and was different before versus after arrival at a reward site. Many single units in ventral striatum phase-locked their discharge pattern to the gamma oscillations of the LFPs. Phase-locking occurred more often in reward-related than in reward-unrelated neurons and LFPs. A substantial number of simultaneously recorded LFPs correlated poorly with each other in terms of gamma rhythmicity, indicating that the expression of gamma activity was heterogeneous and regionally differentiated. The orchestration of LFPs and single-unit activity by way of gamma rhythmicity sheds light on the functional architecture of the ventral striatum and the temporal coordination of ventral striatal activity for modulating downstream areas and regulating synaptic plasticity.


2002 ◽  
Vol 36 (1) ◽  
pp. 9-30 ◽  
Author(s):  
Allan N Schore

Objective: This review integrates recent advances in attachment theory, affective neuroscience, developmental stress research, and infant psychiatry in order to delineate the developmental precursors of posttraumatic stress disorder. Method: Existing attachment, stress physiology, trauma, and neuroscience literatures were collected using Index Medicus/Medline and Psychological Abstracts. This converging interdisciplinary data was used as a theoretical base for modelling the effects of early relational trauma on the developing central and autonomic nervous system activities that drive attachment functions. Results: Current trends that integrate neuropsychiatry, infant psychiatry, and clinical psychiatry are generating more powerful models of the early genesis of a predisposition to psychiatric disorders, including PTSD. Data are presented which suggest that traumatic attachments, expressed in episodes of hyperarousal and dissociation, are imprinted into the developing limbic and autonomic nervous systems of the early maturing right brain. These enduring structural changes lead to the inefficient stress coping mechanisms that lie at the core of infant, child, and adult posttraumatic stress disorders. Conclusions: Disorganised-disoriented insecure attachment, a pattern common in infants abused in the first 2 years of life, is psychologically manifest as an inability to generate a coherent strategy for coping with relational stress. Early abuse negatively impacts the developmental trajectory of the right brain, dominant for attachment, affect regulation, and stress modulation, thereby setting a template for the coping deficits of both mind and body that characterise PTSD symptomatology. These data suggest that early intervention programs can significantly alter the intergenerational transmission of posttraumatic stress disorders.


1999 ◽  
Vol 82 (5) ◽  
pp. 2441-2450 ◽  
Author(s):  
Solange van der Linden ◽  
Ferruccio Panzica ◽  
Marco de Curtis

Fast oscillations at 25–80 Hz (gamma activity) have been proposed to play a role in attention-related mechanisms and synaptic plasticity in cortical structures. Recently, it has been demonstrated that the preservation of the entorhinal cortex is necessary to maintain gamma oscillations in the hippocampus. Because gamma activity can be reproduced in vitro by cholinergic activation, this study examined the characteristics of gamma oscillations induced by arterial perfusion or local intracortical injections of carbachol in the entorhinal cortex of the in vitro isolated guinea pig brain preparation. Shortly after carbachol administration, fast oscillatory activity at 25.2–28.2 Hz was observed in the medial but not in the lateral entorhinal cortex. Such activity was transiently associated with oscillations in the theta range that showed a variable pattern of distribution in the entorhinal cortex. No oscillatory activity was observed when carbachol was injected in the lateral entorhinal cortex. Gamma activity in the medial entorhinal cortex showed a phase reversal at 200–400 μm, had maximal amplitude at 400–500 μm depth, and was abolished by arterial perfusion of atropine (5 μM). Local carbachol application in the medial entorhinal cortex induced gamma oscillations in the hippocampus, whereas no oscillations were observed in the amygdala and in the piriform, periamygdaloid, and perirhinal cortices ipsilateral and contralateral to the carbachol injection. Hippocampal oscillations had higher frequency than the gamma activity recorded in the entorhinal cortex, suggesting the presence of independent generators in the two structures. The selective ability of the medial but not the lateral entorhinal cortex to generate gamma activity in response to cholinergic activation suggests a differential mode of signal processing in entorhinal cortex subregions.


2019 ◽  
Vol 122 (4) ◽  
pp. 1735-1744 ◽  
Author(s):  
Peter H. Donaldson ◽  
Melissa Kirkovski ◽  
Joel S. Yang ◽  
Soukayna Bekkali ◽  
Peter G. Enticott

The right temporoparietal junction (rTPJ) is a multisensory integration hub that is increasingly utilized as a target of stimulation studies exploring its rich functional network roles and potential clinical applications. While transcranial direct current stimulation (tDCS) is frequently employed in such studies, there is still relatively little known regarding its local and network neurophysiological effects, particularly at important nonmotor sites such as the rTPJ. The current study applied either anodal, cathodal, or sham high-definition tDCS to the rTPJ of 53 healthy participants and used offline EEG to assess the impacts of stimulation on resting state (eyes open and eyes closed) band power and coherence. Temporoparietal and central region delta power was increased after anodal stimulation (the latter trend only), whereas cathodal stimulation increased frontal region delta and theta power. Increased coherence between right and left temporoparietal regions was also observed after anodal stimulation. All significant effects occurred in the eyes open condition. These findings are discussed with reference to domain general and mechanistic theories of rTPJ function. Low-frequency oscillatory activity may exert long-range inhibitory network influences that enable switching between and integration of endogenous/exogenous processing streams. NEW & NOTEWORTHY Through the novel use of high-definition transcranial direct current stimulation (tDCS) and EEG, we provide evidence that both anodal and cathodal stimulation of the right temporoparietal junction selectively modulate slow-wave power and coherence in distributed network regions of known relevance to proposed temporoparietal junction functionality. These results also provide direct evidence of the ability of tDCS to modulate oscillatory activity at a long-range network level, which may have explanatory power in terms of both neurophysiological and behavioral effects.


2020 ◽  
Vol 42 ◽  
pp. e44453
Author(s):  
Mariucha Ramella Marcon Nemer ◽  
Bruna de Souza Nogueira ◽  
Fernanda do Nascimento de Lemos Campos ◽  
Márcia Cristina da Silva ◽  
Morgana Ducatti Alves ◽  
...  

The rights of children and adolescents are provided by law and it is the duty of the State, family and society to care for them. Health and education professionals are responsible for reporting suspected or confirmed cases of rights violation. This study aimed to investigate the prevalence and qualification of violation of children’s and adolescents’ rights in the State of Paraná between 2009 and 2014. A descriptive and observational quantitative study was carried out based on the records of the Child Protective Services in Paraná, accessed through the Information System for Childhood and Adolescence (SIPIA). A total of 129.123 violations of rights were found. Among those cases, the right to familiar and communitarian companionship stands out with the greatest number of violations, followed by the right to education, culture, sports and leisure. Mothers were found to be the main aggressors, followed by fathers, and sexual violence/abuse was the most prevalent type of violence. In conclusion, there was a significant amount of violation of children’s and adolescents’ rights in the State of Paraná during the period covered by this research, and it has increased over the years. Besides, we found out that there is a predisposition of gender and age group for each variable analyzed.


Sign in / Sign up

Export Citation Format

Share Document