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1.
J Interpers Violence ; : 8862605241234348, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38450674

RESUMEN

Despite the well-documented link between child maltreatment (CM) and mental health, evidence suggests substantial variability in the post-traumatic sequelae of CM across cultures. The perceived acceptability of CM in one's community might moderate the association between CM and mental health, but little research has been conducted on it so far. This study examined how the perceived acceptability of CM may influence the relationship between CM experiences and post-traumatic symptoms in individuals from four different continents and if the pattern of associations is the same across countries. We recruited a sample of 478 adults from Cameroon (n = 111), Canada (n = 137), Japan (n = 108), and Germany (n = 122). We administered online questionnaires and performed multiple group moderation analyses for total CM, neglect, physical abuse, emotional maltreatment, sexual abuse, and exposure to domestic violence (DV). A significant positive main effect of CM on post-traumatic symptoms was found in the overall sample and in Cameroon; in Germany, only neglect and emotional maltreatment were positively associated to post-traumatic symptoms. Moderation effects were identified; the perceived acceptability of neglect in Cameroon and Germany and of exposure to DV in Cameroon had a dampening effect on the relationship between CM experiences and post-traumatic symptoms. Our findings confirm that CM experiences entail long-term post-traumatic sequelae that can vary across cultures and CM subtypes and further our understanding of this issue by showing that the perceived acceptability of CM may be an understudied moderator.

2.
J Neurosci Methods ; 405: 110106, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38453060

RESUMEN

BACKGROUND: Single-pulse electrical stimulation (SPES) is an established technique used to map functional effective connectivity networks in treatment-refractory epilepsy patients undergoing intracranial-electroencephalography monitoring. While the connectivity path between stimulation and recording sites has been explored through the integration of structural connectivity, there are substantial gaps, such that new modeling approaches may advance our understanding of connectivity derived from SPES studies. NEW METHOD: Using intracranial electrophysiology data recorded from a single patient undergoing stereo-electroencephalography (sEEG) evaluation, we employ an automated detection method to identify early response components, C1, from pulse-evoked potentials (PEPs) induced by SPES. C1 components were utilized for a novel topology optimization method, modeling 3D electrical conductivity to infer neural pathways from stimulation sites. Additionally, PEP features were compared with tractography metrics, and model results were analyzed with respect to anatomical features. RESULTS: The proposed optimization model resolved conductivity paths with low error. Specific electrode contacts displaying high error correlated with anatomical complexities. The C1 component strongly correlated with additional PEP features and displayed stable, weak correlations with tractography measures. COMPARISON WITH EXISTING METHOD: Existing methods for estimating neural signal pathways are imaging-based and thus rely on anatomical inferences. CONCLUSIONS: These results demonstrate that informing topology optimization methods with human intracranial SPES data is a feasible method for generating 3D conductivity maps linking electrical pathways with functional neural ensembles. PEP-estimated effective connectivity is correlated with but distinguished from structural connectivity. Modeled conductivity resolves connectivity pathways in the absence of anatomical priors.


Asunto(s)
Electroencefalografía , Potenciales Evocados , Humanos , Potenciales Evocados/fisiología , Electroencefalografía/métodos , Electrocorticografía/métodos , Mapeo Encefálico/métodos , Estimulación Eléctrica/métodos , Encéfalo/diagnóstico por imagen
3.
Sci Rep ; 14(1): 2652, 2024 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-38332136

RESUMEN

Neuromodulation through implantable pulse generators (IPGs) represents an important treatment approach for neurological disorders. While the field has observed the success of state-of-the-art interventions, such as deep brain stimulation (DBS) or responsive neurostimulation (RNS), implantable systems face various technical challenges, including the restriction of recording from a limited number of brain sites, power management, and limited external access to the assessed neural data in a continuous fashion. To the best of our knowledge, for the first time in this study, we investigated the feasibility of recording human intracranial EEG (iEEG) using a benchtop version of the Brain Interchange (BIC) unit of CorTec, which is a portable, wireless, and externally powered implant with sensing and stimulation capabilities. We developed a MATLAB/SIMULINK-based rapid prototyping environment and a graphical user interface (GUI) to acquire and visualize the iEEG captured from all 32 channels of the BIC unit. We recorded prolonged iEEG (~ 24 h) from three human subjects with externalized depth leads using the BIC and commercially available clinical amplifiers simultaneously in the epilepsy monitoring unit (EMU). The iEEG signal quality of both streams was compared, and the results demonstrated a comparable power spectral density (PSD) in all the systems in the low-frequency band (< 80 Hz). However, notable differences were primarily observed above 100 Hz, where the clinical amplifiers were associated with lower noise floor (BIC-17 dB vs. clinical amplifiers < - 25 dB). We employed an established spike detector to assess and compare the spike rates in each iEEG stream. We observed over 90% conformity between the spikes rates and their spatial distribution captured with BIC and clinical systems. Additionally, we quantified the packet loss characteristic in the iEEG signal during the wireless data transfer and conducted a series of simulations to compare the performance of different interpolation methods for recovering the missing packets in signals at different frequency bands. We noted that simple linear interpolation has the potential to recover the signal and reduce the noise floor with modest packet loss levels reaching up to 10%. Overall, our results indicate that while tethered clinical amplifiers exhibited noticeably better noise floor above 80 Hz, epileptic spikes can still be detected successfully in the iEEG recorded with the externally powered wireless BIC unit opening the road for future closed-loop neuromodulation applications with continuous access to brain activity.


Asunto(s)
Electrocorticografía , Epilepsia , Humanos , Electrocorticografía/métodos , Benchmarking , Encéfalo/fisiología , Epilepsia/terapia , Mapeo Encefálico/métodos , Electroencefalografía/métodos
4.
Brain Stimul ; 16(6): 1792-1798, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38135358

RESUMEN

BACKGROUND: Deep brain stimulation (DBS) and other neuromodulatory techniques are being increasingly utilized to treat refractory neurologic and psychiatric disorders. OBJECTIVE: /Hypothesis: To better understand the circuit-level pathophysiology of treatment-resistant depression (TRD) and treat the network-level dysfunction inherent to this challenging disorder, we adopted an approach of inpatient intracranial monitoring borrowed from the epilepsy surgery field. METHODS: We implanted 3 patients with 4 DBS leads (bilateral pair in both the ventral capsule/ventral striatum and subcallosal cingulate) and 10 stereo-electroencephalography (sEEG) electrodes targeting depression-relevant network regions. For surgical planning, we used an interactive, holographic visualization platform to appreciate the 3D anatomy and connectivity. In the initial surgery, we placed the DBS leads and sEEG electrodes using robotic stereotaxy. Subjects were then admitted to an inpatient monitoring unit for depression-specific neurophysiological assessments. Following these investigations, subjects returned to the OR to remove the sEEG electrodes and internalize the DBS leads to implanted pulse generators. RESULTS: Intraoperative testing revealed positive valence responses in all 3 subjects that helped verify targeting. Given the importance of the network-based hypotheses we were testing, we required accurate adherence to the surgical plan (to engage DBS and sEEG targets) and stability of DBS lead rotational position (to ensure that stimulation field estimates of the directional leads used during inpatient monitoring were relevant chronically), both of which we confirmed (mean radial error 1.2±0.9 mm; mean rotation 3.6±2.6°). CONCLUSION: This novel hybrid sEEG-DBS approach allows detailed study of the neurophysiological substrates of complex neuropsychiatric disorders.


Asunto(s)
Estimulación Encefálica Profunda , Trastorno Depresivo Resistente al Tratamiento , Epilepsia , Humanos , Epilepsia/terapia , Electroencefalografía/métodos , Trastorno Depresivo Resistente al Tratamiento/terapia , Electrodos , Estimulación Encefálica Profunda/métodos , Electrodos Implantados
5.
bioRxiv ; 2023 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-37986830

RESUMEN

Background: Single-pulse electrical stimulation (SPES) is an established technique used to map functional effective connectivity networks in treatment-refractory epilepsy patients undergoing intracranial-electroencephalography monitoring. While the connectivity path between stimulation and recording sites has been explored through the integration of structural connectivity, there are substantial gaps, such that new modeling approaches may advance our understanding of connectivity derived from SPES studies. New Method: Using intracranial electrophysiology data recorded from a single patient undergoing sEEG evaluation, we employ an automated detection method to identify early response components, C1, from pulse-evoked potentials (PEPs) induced by SPES. C1 components were utilized for a novel topology optimization method, modeling 3D conductivity propagation from stimulation sites. Additionally, PEP features were compared with tractography metrics, and model results were analyzed with respect to anatomical features. Results: The proposed optimization model resolved conductivity paths with low error. Specific electrode contacts displaying high error correlated with anatomical complexities. The C1 component strongly correlates with additional PEP features and displayed stable, weak correlations with tractography measures. Comparison with existing methods: Existing methods for estimating conductivity propagation are imaging-based and thus rely on anatomical inferences. Conclusions: These results demonstrate that informing topology optimization methods with human intracranial SPES data is a feasible method for generating 3D conductivity maps linking electrical pathways with functional neural ensembles. PEP-estimated effective connectivity is correlated with but distinguished from structural connectivity. Modeled conductivity resolves connectivity pathways in the absence of anatomical priors.

6.
Eur J Psychotraumatol ; 14(2): 2264119, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37830143

RESUMEN

Background: Post-traumatic growth (PTG) and resilience, regarded as positive psychological change following a traumatic experience, are under-researched across cultures in people exposed to child maltreatment (CM).Objective: We investigated how experiences and the perceived acceptability of CM are related to resilience and PTG in countries with different cultures, living standards, and gross national income.Method: A total of 478 adults from Cameroon (n = 111), Canada (n = 137), Japan (n = 108), and Germany (n = 122) completed an online survey with self-reported questionnaires, including the Brief Resilience Scale and the Post Traumatic Growth Inventory-Short Form.Results: Across countries, self-reported male gender and age were positively associated with resilience, while experiences of physical abuse and emotional maltreatment were negatively associated with resilience. Experiences of emotional maltreatment were positively associated with PTG. Higher levels of PTG and resilience were found amongst Cameroonian participants as compared to other countries.Conclusion: Our results suggest that positive changes following CM can vary significantly across cultures and that experiences of specific CM subtypes, but not the perceived acceptability of CM, may be important for a deeper understanding of how individuals overcome trauma and develop salutogenic outcomes. Our findings may inform CM intervention programmes for an enhanced cultural sensitivity.


Across the four countries (Canada, Cameroon, Germany, Japan), more experiences of physical abuse and emotional maltreatment were associated with lower resilience; more experiences of emotional maltreatment were associated with greater post-traumatic growth.Higher levels of post-traumatic growth and resilience were found in Cameroon as compared to other countries.Positive changes following child maltreatment vary across cultures and experiences of specific child maltreatment subtypes, but the perceived acceptability of child maltreatment did not exert an influence on salutogenic post-traumatic outcomes.


Asunto(s)
Adultos Sobrevivientes del Maltrato a los Niños , Crecimiento Psicológico Postraumático , Resiliencia Psicológica , Adulto , Femenino , Humanos , Masculino , Adultos Sobrevivientes del Maltrato a los Niños/psicología , Comparación Transcultural
7.
bioRxiv ; 2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37693557

RESUMEN

Depression is associated with a cognitive bias towards negative information and away from positive information. This biased emotion processing may underlie core depression symptoms, including persistent feelings of sadness or low mood and a reduced capacity to experience pleasure. The neural mechanisms responsible for this biased emotion processing remain unknown. Here, we had a unique opportunity to record stereotactic electroencephalography (sEEG) signals in the amygdala and prefrontal cortex (PFC) from 5 treatment-resistant depression (TRD) patients and 12 epilepsy patients (as control) while they participated in an affective bias task in which happy and sad faces were rated. First, compared with the control group, patients with TRD showed increased amygdala responses to sad faces in the early stage (around 300 ms) and decreased amygdala responses to happy faces in the late stage (around 600 ms) following the onset of faces. Further, during the late stage of happy face processing, alpha-band activity in PFC as well as alpha-phase locking between the amygdala and PFC were significantly greater in TRD patients compared to the controls. Second, after deep brain stimulation (DBS) delivered to bilateral subcallosal cingulate (SCC) and ventral capsule/ventral striatum (VC/VS), atypical amygdala and PFC processing of happy faces in TRD patients remitted toward the normative pattern. The increased amygdala activation during the early stage of sad face processing suggests an overactive bottom-up processing system in TRD. Meanwhile, the reduced amygdala response during the late stage of happy face processing could be attributed to inhibition by PFC through alpha-band oscillation, which can be released by DBS in SCC and VC/VS.

8.
Child Abuse Negl ; 143: 106270, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37301113

RESUMEN

BACKGROUND: Acceptable parental behaviors and practices toward a child vary across countries and may impact the risk of exposure to maltreatment. Conversely, prior experiences of maltreatment as a child may influence the acceptability of child maltreatment (CM) behaviors. OBJECTIVE: This exploratory study examined the association between CM experiences and perceived acceptability of CM using data from four countries representing different cultures, living standards, and gross national income. PARTICIPANTS AND SETTING: We recruited a convenience sample of 478 adults from Cameroon (n = 111), Canada (n = 137), Japan (n = 108), and Germany (n = 122) through online postings on social media. METHODS: We administered questionnaires and conducted a three-stage hierarchical multiple regression with perceived acceptability of CM subscales as the dependent variable. RESULTS: In all countries, higher scores of childhood neglect were associated with greater perceived acceptability of neglect in one's community (p < .001). Equally, our results showed that higher scores of childhood neglect or sexual abuse were associated with greater perceived acceptability of sexual abuse (p < .044). However, we did not find a significant relationship between other forms of CM (i.e., physical abuse, emotional maltreatment, exposure to domestic violence), and their perceived acceptability. CONCLUSIONS: Our findings suggest that experiences of some CM types, namely neglect and sexual abuse, may be associated with the perception that these are more acceptable within one's community. Perceived acceptability of CM might be a driver that can either prevent or perpetuate CM. Therefore, intervention and prevention programs could incorporate a deeper cross-cultural understanding and assessment of these social norms in order to foster meaningful behavioral changes.


Asunto(s)
Maltrato a los Niños , Adulto , Humanos , Niño , Maltrato a los Niños/psicología , Comparación Transcultural , Abuso Físico , Emociones , Encuestas y Cuestionarios
9.
Elife ; 112022 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-36169132

RESUMEN

Posterior cingulate cortex (PCC) is an enigmatic region implicated in psychiatric and neurological disease, yet its role in cognition remains unclear. Human studies link PCC to episodic memory and default mode network (DMN), while findings from the non-human primate emphasize executive processes more associated with the cognitive control network (CCN) in humans. We hypothesized this difference reflects an important functional division between dorsal (executive) and ventral (episodic) PCC. To test this, we utilized human intracranial recordings of population and single unit activity targeting dorsal PCC during an alternated executive/episodic processing task. Dorsal PCC population responses were significantly enhanced for executive, compared to episodic, task conditions, consistent with the CCN. Single unit recordings, however, revealed four distinct functional types with unique executive (CCN) or episodic (DMN) response profiles. Our findings provide critical electrophysiological data from human PCC, bridging incongruent views within and across species, furthering our understanding of PCC function.


Asunto(s)
Giro del Cíngulo , Memoria Episódica , Encéfalo/fisiología , Mapeo Encefálico , Cognición/fisiología , Giro del Cíngulo/fisiología , Humanos , Imagen por Resonancia Magnética , Neuronas
10.
PLoS Biol ; 20(6): e3001701, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35763497

RESUMEN

New findings in PLOS Biology show that visual gamma oscillations are greatly attenuated by small spatial discontinuities in visual stimuli, suggesting that their genesis occurs in response to predictable regularities in the visual world.


Asunto(s)
Corteza Visual , Animales , Corteza Visual Primaria , Primates , Corteza Visual/fisiología
11.
Psychother Psychosom ; 91(4): 238-251, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35381589

RESUMEN

Childhood maltreatment (CM) is linked to impairments in various domains of social functioning. Here, we argue that it is critical to identify factors that underlie impaired social functioning as well as processes that mediate the beneficial health effects of positive relationships in individuals exposed to CM. Key research recommendations are presented, focusing on: (1) identifying attachment-related alterations in specific inter- and intrapersonal processes (e.g., regulation of closeness and distance) that underlie problems in broader domains of social functioning (e.g., lack of perceived social support) in individuals affected by CM; (2) identifying internal (e.g., current emotional state) and external situational factors (e.g., cultural factors, presence of close others) that modulate alterations in specific social processes; and (3) identifying mechanisms that explain the positive health effects of intact social functioning. Methodological recommendations include: (1) assessing social processes through interactive and (close to) real-life assessments inside and outside the laboratory; (2) adopting an interdisciplinary, lifespan perspective to assess social processes, using multi-method assessments; (3) establishing global research collaborations to account for cultural influences on social processes and enable replications across laboratories and countries. The proposed line of research will contribute to globally develop and refine interventions that prevent CM and further positive relationships, which - likely through buffering the effects of chronic stress and corresponding allostatic load - foster resilience and improve mental and physical health, thereby reducing personal suffering and the societal and economic costs of CM and its consequences. Interventions targeting euthymia and psychological well-being are promising therapeutic concepts in this context.


Asunto(s)
Interacción Social , Apoyo Social , Emociones , Humanos
12.
J Community Psychol ; 50(6): 2578-2596, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35143056

RESUMEN

AIMS: This study aims to: (1) explore the links between past exposure to potentially traumatic events, fear of contracting COVID-19 and perceived stress; (2) investigate how the exposure to traumagenic experiences affects one's locus of control over their health; and (3) examine fear, stress reactions and differences in health locus of control across three different sociocultural contexts. METHODS: A total of 524 adult participants were recruited from Egypt, Germany, and Italy through online channels. Self-reporting instruments were used to assess previous exposure to potentially traumatic events, PTSD symptoms, fear of COVID-19, perceived stress, and health locus of control. RESULTS: Our findings highlight differences in reaction to COVID-19 in relation to past exposure to potentially traumatic events and country of residence, both of which may inform tailored community-based intervention practices. CONCLUSION: The impact of COVID-19 might be particularly disruptive for people who survived potentially traumatic experiences. Nevertheless, the mass mental health impact of the COVID-19 pandemic varies across different sociocultural contexts.


Asunto(s)
COVID-19 , Trastornos por Estrés Postraumático , Adulto , Comparación Transcultural , Egipto/epidemiología , Alemania/epidemiología , Humanos , Italia/epidemiología , Pandemias , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/epidemiología
13.
J Neurosci ; 42(6): 1054-1067, 2022 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-34965979

RESUMEN

Narrowband γ oscillations (NBG: ∼20-60 Hz) in visual cortex reflect rhythmic fluctuations in population activity generated by underlying circuits tuned for stimulus location, orientation, and color. A variety of theories posit a specific role for NBG in encoding and communicating this information within visual cortex. However, recent findings suggest a more nuanced role for NBG, given its dependence on certain stimulus feature configurations, such as coherent-oriented edges and specific hues. Motivated by these factors, we sought to quantify the independent and joint tuning properties of NBG to oriented and color stimuli using intracranial recordings from the human visual cortex (male and female). NBG was shown to display a cardinal orientation bias (horizontal) and also an end- and mid-spectral color bias (red/blue and green). When jointly probed, the cardinal bias for orientation was attenuated and an end-spectral preference for red and blue predominated. This loss of mid-spectral tuning occurred even for recording sites showing large responses to uniform green stimuli. Our results demonstrate the close, yet complex, link between the population dynamics driving NBG oscillations and known feature selectivity biases for orientation and color within visual cortex. Such a bias in stimulus tuning imposes new constraints on the functional significance of the visual γ rhythm. More generally, these biases in population electrophysiology will need to be considered in experiments using orientation or color features to examine the role of visual cortex in other domains, such as working memory and decision-making.SIGNIFICANCE STATEMENT Oscillations in electrophysiological activity occur in visual cortex in response to stimuli that strongly drive the orientation or color selectivity of visual neurons. The significance of this induced "γ rhythm" to brain function remains unclear. Answering this question requires understanding how and why some stimuli can reliably generate oscillatory γ activity while others do not. We examined how different orientations and colors independently and jointly modulate γ oscillations in the human brain. Our data show that γ oscillations are greatest for certain orientations and colors that reflect known response biases in visual cortex. Such findings complicate the functional significance of γ oscillations but open new avenues for linking circuits to population dynamics in visual cortex.


Asunto(s)
Percepción de Color/fisiología , Ritmo Gamma/fisiología , Orientación Espacial/fisiología , Corteza Visual/fisiología , Adulto , Electrocorticografía , Femenino , Humanos , Masculino , Persona de Mediana Edad
14.
Cell Rep ; 35(13): 109304, 2021 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-34192546

RESUMEN

High-frequency activity bursts in the hippocampus, known as ripples, are thought to support memory consolidation during "offline" states, such as sleep. Recently, human hippocampal ripples have been observed during "online" episodic memory tasks. It remains unclear whether similar ripple activity occurs during other cognitive states, including different types of episodic memory. However, identifying genuine ripple events in the human hippocampus is challenging. To address these questions, spectro-temporal ripple identification was applied to human hippocampal recordings across a variety of cognitive tasks. Overall, ripple attributes were stable across tasks of visual perception and associative memory, with mean rates lower than offline states of rest and sleep. In contrast, while more complex visual attention tasks did not modulate ripple attributes, rates were enhanced for more complex autobiographical memory conditions. Therefore, hippocampal ripples reliably occur across cognitive states but are specifically enhanced during offline states and complex memory processes, consistent with a role in consolidation.


Asunto(s)
Potenciales de Acción/fisiología , Hipocampo/fisiología , Análisis y Desempeño de Tareas , Adulto , Artefactos , Cognición/fisiología , Electrodos , Femenino , Humanos , Masculino , Memoria Episódica , Persona de Mediana Edad , Sueño/fisiología , Factores de Tiempo , Adulto Joven
15.
Trends Cogn Sci ; 24(7): 501-503, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32336605

RESUMEN

Gamma oscillations have been argued to support visual perception by synchronizing the processing and transfer of information within and across areas of visual cortex. Here, we highlight recent findings implicating the influence of color on visual gamma oscillations and how these observations may relate to local cortical tuning and organization.


Asunto(s)
Corteza Visual , Humanos , Estimulación Luminosa , Visión Ocular , Percepción Visual
16.
Behav Brain Res ; 378: 112248, 2020 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-31614184

RESUMEN

Action execution is prone to errors and, while engaged in interaction, our brain is tuned to detect deviations from what one expects from other's action. Prior research has shown that Event-Related-Potentials (ERPs) are specifically modulated by the observation of action mistakes interfering with goal achievement. However, in complex and modular actions, embedded motor errors do not necessarily produce an immediate effect on the global goal. Here we dissociate embedded motor goals from global action goals by asking subjects to observe familiar but untrained knotting actions. During knotting an embedded motor error (i.e. the rope is inserted top-down instead of bottom-up during the formation of a loop) while not producing any immediate mistake, may strongly affect the final result. We found that embedded errors elicit in the observer specific early fronto-central negativity (120-180 ms). In a second experiment, we online administered exicitatory transcranial magnetic stimulation (TMS) over central (C3) or occipital (Oz) scalp locations, at the timing of the ERP components observed in the first experiment. C3 stimulation produced a significant improvement in embedded error discrimination performance. These results show that sensorimotor areas are instrumental in the early detection of embedded motor errors. We conclude that others' embedded errors provide fundamental cues which, inserted within a complex hierarchical action plan, might be used by the observer to anticipate whether an action will eventually fail.


Asunto(s)
Potenciales Evocados/fisiología , Objetivos , Actividad Motora/fisiología , Desempeño Psicomotor/fisiología , Corteza Sensoriomotora/fisiología , Percepción Visual/fisiología , Adulto , Anticipación Psicológica , Señales (Psicología) , Electroencefalografía , Femenino , Humanos , Masculino , Estimulación Magnética Transcraneal , Adulto Joven
17.
Curr Biol ; 29(20): 3345-3358.e7, 2019 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-31588003

RESUMEN

Neocortical gamma activity has long been hypothesized as a mechanism for synchronizing brain regions to support visual perception and cognition more broadly. Although early studies focused on narrowband gamma oscillations (∼20-60 Hz), recent work has emphasized a more broadband "high-gamma" response (∼70-150+ Hz). These responses are often conceptually or analytically treated as synonymous markers of gamma activity. Using high-density intracranial recordings from the human visual cortex, we challenge this view by showing distinct spectral, temporal, and functional properties of narrow and broadband gamma. Across four experiments, narrowband gamma was strongly selective for gratings and long-wavelength colors, displaying a delayed response onset, sustained temporal profile, and contrast-dependent peak frequency. In addition, induced narrowband gamma oscillations lacked phase consistency across stimulus repetitions and displayed highly focal inter-site synchronization. In contrast, broadband gamma was consistently observed for all presented stimuli, displaying a rapid response onset, transient temporal profile, and invariant spectral properties. We exploited stimulus tuning to highlight the functional dissociation of these distinct signals, reconciling prior inconsistencies across species and stimuli regarding the ubiquity of visual gamma oscillations during natural vision. The occurrence of visual narrowband gamma oscillations, unlike broadband high gamma, appears contingent on specific structural and chromatic stimulus attributes intersecting with the receptive field. Together, these findings have important implications for the study, analysis, and functional interpretation of neocortical gamma-range activity.


Asunto(s)
Ritmo Gamma/fisiología , Corteza Visual/fisiología , Percepción Visual/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
18.
Neuropsychologia ; 128: 290-296, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-29317325

RESUMEN

Listening to speech has been shown to activate motor regions, as measured by corticobulbar excitability. In this experiment, we explored if motor regions are also recruited during listening to non-native speech, for which we lack both sensory and motor experience. By administering Transcranial Magnetic Stimulation (TMS) over the left motor cortex we recorded corticobulbar excitability of the lip muscles when Italian participants listened to native-like and non-native German vowels. Results showed that lip corticobulbar excitability increased for a combination of lip use during articulation and non-nativeness of the vowels. Lip corticobulbar excitability was further related to measures obtained in perception and production tasks showing a negative relationship with nativeness ratings and a positive relationship with the uncertainty of lip movement during production of the vowels. These results suggest an active and compensatory role of the motor system during listening to perceptually/articulatory unfamiliar phonemes.


Asunto(s)
Percepción Auditiva/fisiología , Corteza Motora/fisiología , Percepción del Habla/fisiología , Adulto , Electromiografía , Potenciales Evocados Motores , Femenino , Humanos , Lenguaje , Labio/inervación , Labio/fisiología , Masculino , Medición de la Producción del Habla , Estimulación Magnética Transcraneal , Adulto Joven
19.
Integr Psychol Behav Sci ; 53(3): 374-396, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-29766475

RESUMEN

This paper discusses the problem of the role of language in autobiographical memory, that is barely considered in studies on autobiographical memories and narratives. As a matter of fact, most of the current studies on autobiographical memory confounded memory and narrative together. The present paper focuses on two main issues. Firstly, it debates how narratives contribute to the construction of autobiographical memories through self-other communication. Secondly, it reflects on how language and communication should be manipulated in studies about autobiographical memory. This paper is made of three sections: the first section discusses the role of language, particularly in the form of narrative, as a social tool by which autobiographical memories can be organised in a life story; the second section examines previous methods of investigation used in the study of autobiographical memories; finally, the third section proposes different methodological alternatives to overcome the problems emerging from our analysis of literature.


Asunto(s)
Lenguaje , Memoria Episódica , Memoria , Investigación Conductal/métodos , Señales (Psicología) , Humanos , Narración
20.
Hum Brain Mapp ; 39(1): 189-203, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29024235

RESUMEN

Stopping incipient action activates both the right inferior frontal cortex (rIFC) and the anterior insula (rAI). Controversy has arisen as to whether these comprise a unitary cortical cluster-the rIFC/rAI-or whether rIFC is the primary stopping locus. To address this, we recorded directly from these structures while taking advantage of the high spatiotemporal resolution of closely spaced stereo-electro-encephalographic (SEEG) electrodes. We studied 12 patients performing a stop-signal task. On each trial they initiated a motor response (Go) and tried to stop to an occasional stop signal. Both the rIFC and rAI exhibited an increase in broadband gamma activity (BGA) after the stop signal and within the time of stopping (stop signal reaction time, SSRT), regardless of the success of stopping. The proportion of electrodes with this response was significantly greater in the rIFC than the rAI. Also, the rIFC response preceded that in the rAI. Last, while the BGA increase in rIFC occurred mainly prior to SSRT, the rAI showed a sustained increase in the beta and low gamma bands after the SSRT. In summary, the rIFC was activated soon after the stop signal, prior to and more robustly than the rAI, which on the other hand, showed a more prolonged response after the onset of stopping. Our results are most compatible with the notion that the rIFC is involved in triggering outright stopping in concert with a wider network, while the rAI is likely engaged by other processes, such as arousal, saliency, or behavioral adjustments. Hum Brain Mapp 39:189-203, 2018. © 2017 Wiley Periodicals, Inc.


Asunto(s)
Lóbulo Frontal/fisiología , Inhibición Psicológica , Actividad Motora/fisiología , Adulto , Ondas Encefálicas , Epilepsia Refractaria/fisiopatología , Electrocorticografía , Femenino , Lóbulo Frontal/fisiopatología , Lateralidad Funcional/fisiología , Humanos , Masculino , Factores de Tiempo
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