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1.
Neuron ; 109(6): 1055-1066.e4, 2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33561399

RESUMO

Visual working memory (WM) storage is largely independent between the left and right visual hemifields/cerebral hemispheres, yet somehow WM feels seamless. We studied how WM is integrated across hemifields by recording neural activity bilaterally from lateral prefrontal cortex. An instructed saccade during the WM delay shifted the remembered location from one hemifield to the other. Before the shift, spike rates and oscillatory power showed clear signatures of memory laterality. After the shift, the lateralization inverted, consistent with transfer of the memory trace from one hemisphere to the other. Transferred traces initially used different neural ensembles from feedforward-induced ones, but they converged at the end of the delay. Around the time of transfer, synchrony between the two prefrontal hemispheres peaked in theta and beta frequencies, with a directionality consistent with memory trace transfer. This illustrates how dynamics between the two cortical hemispheres can stitch together WM traces across visual hemifields.


Assuntos
Lateralidade Funcional/fisiologia , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologia , Percepção Visual/fisiologia , Animais , Feminino , Macaca mulatta , Masculino
2.
Nat Commun ; 12(1): 894, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33563989

RESUMO

Prefrontal cortex is critical for cognition. Although much is known about the representation of cognitive variables in the prefrontal cortex, much less is known about the spatio-temporal neural dynamics that underlie cognitive operations. In the present study, we examined information timing and flow across the lateral prefrontal cortex (LPFC), while monkeys carried out a two-armed bandit reinforcement learning task in which they had to learn to select rewarding actions or rewarding objects. When we analyzed signals independently within subregions of the LPFC, we found a task-specific, caudo-rostral gradient in the strength and timing of signals related to chosen objects and chosen actions. In addition, when we characterized information flow among subregions, we found that information flow from action to object representations was stronger from the dorsal to ventral LPFC, and information flow from object to action representations was stronger from the ventral to dorsal LPFC. The object to action effects were more pronounced in object blocks, and also reflected learning specifically in these blocks. These results suggest anatomical segregation followed by the rapid integration of information within the LPFC.


Assuntos
Comportamento de Escolha/fisiologia , Córtex Pré-Frontal/fisiologia , Recompensa , Animais , Mapeamento Encefálico , Aprendizagem , Macaca , Modelos Neurológicos , Neurônios/fisiologia , Córtex Pré-Frontal/citologia , Tempo de Reação/fisiologia , Reforço Psicológico
3.
J Vis Exp ; (167)2021 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-33522512

RESUMO

Transcranial direct current stimulation (tDCS) is a form of non-invasive brain stimulation that changes the likelihood of neuronal firing through modulation of neural resting membranes. Compared to other techniques, tDCS is relatively safe, cost-effective, and can be administered while individuals are engaged in controlled, specific cognitive processes. This latter point is important as tDCS may predominantly affect intrinsically active neural regions. In an effort to test tDCS as a potential treatment for psychiatric illness, the protocol described here outlines a novel procedure that allows the simultaneous application of tDCS during exposure to trauma-related cues using virtual reality (tDCS+VR) for veterans with posttraumatic stress disorder (NCT03372460). In this double-blind protocol, participants are assigned to either receive 2 mA tDCS, or sham stimulation, for 25 minutes while passively watching three 8-minute standardized virtual reality drives through Iraq or Afghanistan, with virtual reality events increasing in intensity during each drive. Participants undergo six sessions of tDCS+VR over the course of 2-3 weeks, and psychophysiology (skin conductance reactivity) is measured throughout each session. This allows testing for within and between session changes in hyperarousal to virtual reality events and adjunctive effects of tDCS. Stimulation is delivered through a built-in rechargeable battery-driven tDCS device using a 1 (anode) x 1 (cathode) unilateral electrode set-up. Each electrode is placed in a 3 x 3 cm (current density 2.22 A/m2) reusable sponge pocket saturated with 0.9% normal saline. Sponges with electrodes are attached to the participant's skull using a rubber headband with the electrodes placed such that they target regions within the ventromedial prefrontal cortex. The virtual reality headset is placed over the tDCS montage in such a way as to avoid electrode interference.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Realidade Virtual , Adolescente , Adulto , Idoso , Método Duplo-Cego , Eletrodos , Feminino , Resposta Galvânica da Pele , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Pré-Frontal/fisiologia , Transtornos de Estresse Pós-Traumáticos/terapia , Estimulação Transcraniana por Corrente Contínua/psicologia
4.
Nat Commun ; 12(1): 1103, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33597516

RESUMO

Neurons in some sensory areas reflect the content of working memory (WM) in their spiking activity. However, this spiking activity is seldom related to behavioral performance. We studied the responses of inferotemporal (IT) neurons, which exhibit object-selective activity, along with Frontal Eye Field (FEF) neurons, which exhibit spatially selective activity, during the delay period of an object WM task. Unlike the spiking activity and local field potentials (LFPs) within these areas, which were poor predictors of behavioral performance, the phase-locking of IT spikes and LFPs with the beta band of FEF LFPs robustly predicted successful WM maintenance. In addition, IT neurons exhibited greater object-selective persistent activity when their spikes were locked to the phase of FEF LFPs. These results reveal that the coordination between prefrontal and temporal cortex predicts the successful maintenance of visual information during WM.


Assuntos
Macaca mulatta/fisiologia , Memória de Curto Prazo/fisiologia , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Lobo Temporal/fisiologia , Potenciais de Ação/fisiologia , Algoritmos , Animais , Lobo Frontal/citologia , Lobo Frontal/fisiologia , Masculino , Modelos Neurológicos , Estimulação Luminosa , Córtex Pré-Frontal/citologia , Lobo Temporal/citologia
5.
Nat Neurosci ; 24(2): 259-265, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33495637

RESUMO

Short-term memory is associated with persistent neural activity that is maintained by positive feedback between neurons. To explore the neural circuit motifs that produce memory-related persistent activity, we measured coupling between functionally characterized motor cortex neurons in mice performing a memory-guided response task. Targeted two-photon photostimulation of small (<10) groups of neurons produced sparse calcium responses in coupled neurons over approximately 100 µm. Neurons with similar task-related selectivity were preferentially coupled. Photostimulation of different groups of neurons modulated activity in different subpopulations of coupled neurons. Responses of stimulated and coupled neurons persisted for seconds, far outlasting the duration of the photostimuli. Photostimuli produced behavioral biases that were predictable based on the selectivity of the perturbed neuronal population, even though photostimulation preceded the behavioral response by seconds. Our results suggest that memory-related neural circuits contain intercalated, recurrently connected modules, which can independently maintain selective persistent activity.


Assuntos
Memória de Curto Prazo/fisiologia , Modelos Neurológicos , Atividade Motora/fisiologia , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Comportamento Animal/fisiologia , Cálcio/metabolismo , Aprendizagem por Discriminação/fisiologia , Camundongos , Vias Neurais/fisiologia
6.
Nature ; 591(7849): 270-274, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33408410

RESUMO

Neural mechanisms that mediate the ability to make value-guided decisions have received substantial attention in humans and animals1-6. Experiments in animals typically involve long training periods. By contrast, choices in the real world often need to be made between new options spontaneously. It is therefore possible that the neural mechanisms targeted in animal studies differ from those required for new decisions, which are typical of human imaging studies. Here we show that the primate medial frontal cortex (MFC)7 is involved in making new inferential choices when the options have not been previously experienced. Macaques spontaneously inferred the values of new options via similarities with the component parts of previously encountered options. Functional magnetic resonance imaging (fMRI) suggested that this ability was mediated by the MFC, which is rarely investigated in monkeys3; MFC activity reflected different processes of comparison for unfamiliar and familiar options. Multidimensional representations of options in the MFC used a coding scheme resembling that of grid cells, which is well known in spatial navigation8,9, to integrate dimensions in this non-physical space10 during novel decision-making. By contrast, the orbitofrontal cortex held specific object-based value representations1,11. In addition, minimally invasive ultrasonic disruption12 of MFC, but not adjacent tissue, altered the estimation of novel choice values.


Assuntos
Comportamento de Escolha/fisiologia , Lobo Frontal/citologia , Lobo Frontal/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Adulto , Animais , Feminino , Células de Grade/fisiologia , Humanos , Imagem por Ressonância Magnética , Masculino , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/fisiologia , Navegação Espacial/fisiologia , Adulto Jovem
7.
Int J Mol Sci ; 22(2)2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33467450

RESUMO

Fear extinction requires coordinated neural activity within the amygdala and medial prefrontal cortex (mPFC). Any behavior has a transcriptomic signature that is modified by environmental experiences, and specific genes are involved in functional plasticity and synaptic wiring during fear extinction. Here, we investigated the effects of optogenetic manipulations of prelimbic (PrL) pyramidal neurons and amygdala gene expression to analyze the specific transcriptional pathways associated to adaptive and maladaptive fear extinction. To this aim, transgenic mice were (or not) fear-conditioned and during the extinction phase they received optogenetic (or sham) stimulations over photo-activable PrL pyramidal neurons. At the end of behavioral testing, electrophysiological (neural cellular excitability and Excitatory Post-Synaptic Currents) and morphological (spinogenesis) correlates were evaluated in the PrL pyramidal neurons. Furthermore, transcriptomic cell-specific RNA-analyses (differential gene expression profiling and functional enrichment analyses) were performed in amygdala pyramidal neurons. Our results show that the optogenetic activation of PrL pyramidal neurons in fear-conditioned mice induces fear extinction deficits, reflected in an increase of cellular excitability, excitatory neurotransmission, and spinogenesis of PrL pyramidal neurons, and associated to strong modifications of the transcriptome of amygdala pyramidal neurons. Understanding the electrophysiological, morphological, and transcriptomic architecture of fear extinction may facilitate the comprehension of fear-related disorders.


Assuntos
Tonsila do Cerebelo/fisiologia , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Medo/fisiologia , Células Piramidais/fisiologia , Transcriptoma/genética , Tonsila do Cerebelo/citologia , Tonsila do Cerebelo/metabolismo , Animais , Fenômenos Eletrofisiológicos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Medo/psicologia , Masculino , Memória/fisiologia , Camundongos Transgênicos , Vias Neurais/citologia , Vias Neurais/metabolismo , Vias Neurais/fisiologia , Optogenética/métodos , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiologia , Células Piramidais/metabolismo , Transmissão Sináptica/fisiologia
8.
Neuron ; 109(5): 852-868.e8, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33482086

RESUMO

Human brain pathways supporting language and declarative memory are thought to have differentiated substantially during evolution. However, cross-species comparisons are missing on site-specific effective connectivity between regions important for cognition. We harnessed functional imaging to visualize the effects of direct electrical brain stimulation in macaque monkeys and human neurosurgery patients. We discovered comparable effective connectivity between caudal auditory cortex and both ventro-lateral prefrontal cortex (VLPFC, including area 44) and parahippocampal cortex in both species. Human-specific differences were clearest in the form of stronger hemispheric lateralization effects. In humans, electrical tractography revealed remarkably rapid evoked potentials in VLPFC following auditory cortex stimulation and speech sounds drove VLPFC, consistent with prior evidence in monkeys of direct auditory cortex projections to homologous vocalization-responsive regions. The results identify a common effective connectivity signature in human and nonhuman primates, which from auditory cortex appears equally direct to VLPFC and indirect to the hippocampus. VIDEO ABSTRACT.


Assuntos
Lobo Frontal/fisiologia , Lobo Temporal/fisiologia , Adolescente , Adulto , Animais , Córtex Auditivo/fisiologia , Mapeamento Encefálico , Estimulação Elétrica , Feminino , Humanos , Macaca mulatta , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiologia , Giro Para-Hipocampal/fisiologia , Córtex Pré-Frontal/fisiologia , Especificidade da Espécie , Adulto Jovem
9.
Neuroimage ; 227: 117655, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33333318

RESUMO

Different cortical regions respond with distinct rhythmic patterns of neural oscillations to Transcranial Magnetic Stimulation (TMS). We investigated natural frequencies induced by TMS in left and right homologous dorsolateral prefrontal cortices (DLPFC) and related hemispheric differences. In 12 healthy young adults, single-pulse TMS was delivered in different blocks close to F3 and F4 channels to target left and right DLPFC. An occipital site near PO3 was stimulated as control. TMS-related spectral perturbation analyses were performed on recorded EEG data. A widespread unspecific increase in theta power was observed for all stimulation sites. However, occipital TMS induced greater alpha activity and a 10.58 Hz natural frequency, while TMS over the left and right DLPFC resulted in similar beta band modulations and a natural frequency of 18.77 and 18.5 Hz, respectively. In particular, TMS-related specific increase in beta activity was stronger for the right than the left DLPFC. The right DLPFC is more specifically tuned to its natural beta frequency when it is directly stimulated by TMS than with TMS over the left counterpart (or a posterior region), while the left DLPFC increases its beta activity more similarly irrespective of whether it is directly stimulated or through right homologous stimulation. These results yield important implications for both basic neuroscience research on inter-hemispheric prefrontal interactions and clinical applications.


Assuntos
Córtex Pré-Frontal/fisiologia , Estimulação Magnética Transcraniana/métodos , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
10.
Neuron ; 109(4): 713-723.e7, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33357385

RESUMO

Knowledge of the structure of a problem, such as relationships between stimuli, enables rapid learning and flexible inference. Humans and other animals can abstract this structural knowledge and generalize it to solve new problems. For example, in spatial reasoning, shortest-path inferences are immediate in new environments. Spatial structural transfer is mediated by cells in entorhinal and (in humans) medial prefrontal cortices, which maintain their co-activation structure across different environments and behavioral states. Here, using fMRI, we show that entorhinal and ventromedial prefrontal cortex (vmPFC) representations perform a much broader role in generalizing the structure of problems. We introduce a task-remapping paradigm, where subjects solve multiple reinforcement learning (RL) problems differing in structural or sensory properties. We show that, as with space, entorhinal representations are preserved across different RL problems only if task structure is preserved. In vmPFC and ventral striatum, representations of prediction error also depend on task structure.


Assuntos
Córtex Entorrinal/fisiologia , Aprendizagem/fisiologia , Córtex Pré-Frontal/fisiologia , Desempenho Psicomotor/fisiologia , Reforço Psicológico , Adulto , Córtex Entorrinal/diagnóstico por imagem , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa/métodos , Córtex Pré-Frontal/diagnóstico por imagem , Distribuição Aleatória , Adulto Jovem
11.
Nature ; 590(7847): 606-611, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33361819

RESUMO

How do we learn about what to learn about? Specifically, how do the neural elements in our brain generalize what has been learned in one situation to recognize the common structure of-and speed learning in-other, similar situations? We know this happens because we become better at solving new problems-learning and deploying schemas1-5-through experience. However, we have little insight into this process. Here we show that using prior knowledge to facilitate learning is accompanied by the evolution of a neural schema in the orbitofrontal cortex. Single units were recorded from rats deploying a schema to learn a succession of odour-sequence problems. With learning, orbitofrontal cortex ensembles converged onto a low-dimensional neural code across both problems and subjects; this neural code represented the common structure of the problems and its evolution accelerated across their learning. These results demonstrate the formation and use of a schema in a prefrontal brain region to support a complex cognitive operation. Our results not only reveal a role for the orbitofrontal cortex in learning but also have implications for using ensemble analyses to tap into complex cognitive functions.


Assuntos
Aprendizagem/fisiologia , Modelos Neurológicos , Córtex Pré-Frontal/fisiologia , Aceleração , Animais , Cognição/fisiologia , Lógica , Masculino , Neurônios/fisiologia , Odorantes/análise , Córtex Pré-Frontal/citologia , Ratos , Ratos Long-Evans , Recompensa
12.
Elife ; 92020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33319747

RESUMO

In many cases of trauma, the same environmental stimuli that become associated with aversive events are experienced on other occasions without adverse consequence. We examined neural circuits underlying partially reinforced fear (PRF), whereby mice received tone-shock pairings on half of conditioning trials. Tone-elicited freezing was lower after PRF conditioning than fully reinforced fear (FRF) conditioning, despite an equivalent number of tone-shock pairings. PRF preferentially activated medial prefrontal cortex (mPFC) and bed nucleus of the stria terminalis (BNST). Chemogenetic inhibition of BNST-projecting mPFC neurons increased PRF, not FRF, freezing. Multiplexing chemogenetics with in vivo neuronal recordings showed elevated infralimbic cortex (IL) neuronal activity during CS onset and freezing cessation; these neural correlates were abolished by chemogenetic mPFC→BNST inhibition. These data suggest that mPFC→BNST neurons limit fear to threats with a history of partial association with an aversive stimulus, with potential implications for understanding the neural basis of trauma-related disorders.


Assuntos
Medo/fisiologia , Córtex Pré-Frontal/fisiologia , Núcleos Septais/fisiologia , Animais , Condicionamento Clássico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/fisiologia , Reforço Psicológico , Incerteza
13.
PLoS Biol ; 18(12): e3001019, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33347436

RESUMO

The mismatch negativity (MMN) is a key biomarker of automatic deviance detection thought to emerge from 2 cortical sources. First, the auditory cortex (AC) encodes spectral regularities and reports frequency-specific deviances. Then, more abstract representations in the prefrontal cortex (PFC) allow to detect contextual changes of potential behavioral relevance. However, the precise location and time asynchronies between neuronal correlates underlying this frontotemporal network remain unclear and elusive. Our study presented auditory oddball paradigms along with "no-repetition" controls to record mismatch responses in neuronal spiking activity and local field potentials at the rat medial PFC. Whereas mismatch responses in the auditory system are mainly induced by stimulus-dependent effects, we found that auditory responsiveness in the PFC was driven by unpredictability, yielding context-dependent, comparatively delayed, more robust and longer-lasting mismatch responses mostly comprised of prediction error signaling activity. This characteristically different composition discarded that mismatch responses in the PFC could be simply inherited or amplified downstream from the auditory system. Conversely, it is more plausible for the PFC to exert top-down influences on the AC, since the PFC exhibited flexible and potent predictive processing, capable of suppressing redundant input more efficiently than the AC. Remarkably, the time course of the mismatch responses we observed in the spiking activity and local field potentials of the AC and the PFC combined coincided with the time course of the large-scale MMN-like signals reported in the rat brain, thereby linking the microscopic, mesoscopic, and macroscopic levels of automatic deviance detection.


Assuntos
Córtex Auditivo/fisiologia , Potenciais Evocados Auditivos/fisiologia , Córtex Pré-Frontal/fisiologia , Estimulação Acústica , Animais , Córtex Auditivo/metabolismo , Percepção Auditiva/fisiologia , Eletroencefalografia/métodos , Feminino , Neurônios/fisiologia , Córtex Pré-Frontal/metabolismo , Ratos , Ratos Long-Evans , Tempo de Reação/fisiologia
14.
Elife ; 92020 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-33357380

RESUMO

The prefrontal cortex (PFC)'s functions are thought to include working memory, as its activity can reflect information that must be temporarily maintained to realize the current goal. We designed a flexible spatial working memory task that required rats to navigate - after distractions and a delay - to multiple possible goal locations from different starting points and via multiple routes. This made the current goal location the key variable to remember, instead of a particular direction or route to the goal. However, across a broad population of PFC neurons, we found no evidence of current-goal-specific memory in any previously reported form - that is differences in the rate, sequence, phase, or covariance of firing. This suggests that such patterns do not hold working memory in the PFC when information must be employed flexibly. Instead, the PFC grouped locations representing behaviorally equivalent task features together, consistent with a role in encoding long-term knowledge of task structure.


Assuntos
Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologia , Memória Espacial/fisiologia , Animais , Objetivos , Masculino , Aprendizagem em Labirinto/fisiologia , Plasticidade Neuronal/fisiologia , Ratos , Ratos Long-Evans
15.
PLoS One ; 15(10): e0229316, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33006966

RESUMO

The prevalence of criticism in everyday social situations, and its empirically demonstrated association with psychopathology, highlight the importance of understanding neural mechanisms underlying the perception and response of individuals to criticism. However, neuroimaging studies to date have been limited largely to maternal criticism. The present study aims to investigate neural responses to observing criticism occurring in the context of three different relationship types: romantic partners, friends, and parents-from a third-party perspective. 49 participants were recruited and asked to rate the perceived criticism for these relationships. Functional near-infrared spectroscopy was used to measure changes in oxygenated haemoglobin levels in the prefrontal cortex when participants read vignettes describing three different scenarios of criticism. Participants were randomly assigned to 3 groups where the given description of the relationship of the protagonist to the source of criticism for each vignette was randomised. A significant interaction between relationship type and perceived criticism ratings for mothers was found in the dorsolateral prefrontal cortex. Compared to low perceived criticism, high perceived criticism individuals showed increased activation reading vignettes describing criticism from romantic partners and parents but decreased activation for those from friends. Findings contribute to understanding neural responses to criticism as observed from a third-party perspective. Future studies can look into differentiating neural responses of personalised experiences of criticism and third-party observations.


Assuntos
Emoções/fisiologia , Amigos/psicologia , Pais/psicologia , Córtex Pré-Frontal/fisiologia , Parceiros Sexuais/psicologia , Adolescente , Adulto , Feminino , Hemoglobinas/metabolismo , Humanos , Relações Interpessoais , Masculino , Neuroimagem , Distribuição Aleatória , Adulto Jovem
16.
Behav Neurosci ; 134(5): 369-383, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33001679

RESUMO

This study investigated whether the application of high definition transcranial DC stimulation (HD-tDCS) to the dorsolateral prefrontal cortex reduces cue-induced food craving when combined with food-specific inhibitory control training. Using a within-subjects design, participants (N = 55) received both active and sham HD-tDCS across 2 sessions while completing a Go/No-Go task in which foods were either associated with response inhibition or response execution. Food craving was measured pre and post stimulation using a standardized questionnaire as well as desire to eat ratings for foods associated with both response inhibition and response execution in the training task. Results revealed no effect of HD-tDCS on reducing state food craving or desire to eat. Due to the COVID-19 pandemic, we were unable to achieve our maximum preplanned sample size or our minimum desired Bayesian evidence strength across all a priori hypotheses; however 6 of the 7 hypotheses converged with moderate or stronger evidence in favor of the null hypothesis over the alternative hypothesis. We discuss the importance of individual differences and provide recommendations for future studies with an emphasis on the importance of cognitive interventions. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Assuntos
Fissura/fisiologia , Preferências Alimentares/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Teorema de Bayes , Estudos Cross-Over , Sinais (Psicologia) , Feminino , Alimentos , Humanos , Masculino , Inquéritos e Questionários , Estimulação Transcraniana por Corrente Contínua/métodos
17.
Nat Commun ; 11(1): 5233, 2020 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-33067461

RESUMO

Decision-making via monitoring others' actions is a cornerstone of interpersonal exchanges. Although the ventral premotor cortex (PMv) and the medial prefrontal cortex (MPFC) are cortical nodes in social brain networks, the two areas are rarely concurrently active in neuroimaging, inviting the hypothesis that they are functionally independent. Here we show in macaques that the ability of the MPFC to monitor others' actions depends on input from the PMv. We found that delta-band coherence between the two areas emerged during action execution and action observation. Information flow especially in the delta band increased from the PMv to the MPFC as the biological nature of observed actions increased. Furthermore, selective blockade of the PMv-to-MPFC pathway using a double viral vector infection technique impaired the processing of observed, but not executed, actions. These findings demonstrate that coordinated activity in the PMv-to-MPFC pathway has a causal role in social action monitoring.


Assuntos
Macaca/fisiologia , Córtex Motor/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Mapeamento Encefálico , Tomada de Decisões , Macaca/psicologia , Masculino , Córtex Motor/química , Córtex Motor/diagnóstico por imagem , Vias Neurais , Córtex Pré-Frontal/química , Córtex Pré-Frontal/diagnóstico por imagem , Comportamento Social
18.
Nat Commun ; 11(1): 4669, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938940

RESUMO

The prefrontal cortex and striatum form a recurrent network whose spiking activity encodes multiple types of learning-relevant information. This spike-encoded information is evident in average firing rates, but finer temporal coding might allow multiplexing and enhanced readout across the connected network. We tested this hypothesis in the fronto-striatal network of nonhuman primates during reversal learning of feature values. We found that populations of neurons encoding choice outcomes, outcome prediction errors, and outcome history in their firing rates also carry significant information in their phase-of-firing at a 10-25 Hz band-limited beta frequency at which they synchronize across lateral prefrontal cortex, anterior cingulate cortex and anterior striatum when outcomes were processed. The phase-of-firing code exceeds information that can be obtained from firing rates alone and is evident for inter-areal connections between anterior cingulate cortex, lateral prefrontal cortex and anterior striatum. For the majority of connections, the phase-of-firing information gain is maximal at phases of the beta cycle that were offset from the preferred spiking phase of neurons. Taken together, these findings document enhanced information of three important learning variables at specific phases of firing in the beta cycle at an inter-areally shared beta oscillation frequency during goal-directed behavior.


Assuntos
Corpo Estriado/fisiologia , Giro do Cíngulo/fisiologia , Aprendizagem/fisiologia , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Análise por Conglomerados , Corpo Estriado/citologia , Sincronização de Fases em Eletroencefalografia , Eletrofisiologia/métodos , Eletrofisiologia/estatística & dados numéricos , Giro do Cíngulo/citologia , Macaca mulatta , Masculino , Rede Nervosa , Córtex Pré-Frontal/citologia , Recompensa
19.
Nat Commun ; 11(1): 4856, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978385

RESUMO

In humans and macaque monkeys, socially relevant face processing is accomplished via a distributed functional network that includes specialized patches in frontal cortex. It is unclear whether a similar network exists in New World primates, who diverged ~35 million years from Old World primates. The common marmoset is a New World primate species ideally placed to address this question given their complex social repertoire. Here, we demonstrate the existence of a putative high-level face processing network in marmosets. Like Old World primates, marmosets show differential activation in anterior cingulate and lateral prefrontal cortices while they view socially relevant videos of marmoset faces. We corroborate the locations of these frontal regions by demonstrating functional and structural connectivity between these regions and temporal lobe face patches. Given the evolutionary separation between macaques and marmosets, our results suggest this frontal network specialized for social face processing predates the separation between Platyrrhini and Catarrhini.


Assuntos
Callithrix/fisiologia , Face/fisiologia , Lobo Frontal/fisiologia , Animais , Mapeamento Encefálico , Feminino , Lobo Frontal/diagnóstico por imagem , Giro do Cíngulo , Humanos , Imagem por Ressonância Magnética , Córtex Pré-Frontal/fisiologia , Lobo Temporal
20.
Nat Commun ; 11(1): 4590, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929067

RESUMO

An adaptive memory system rarely learns information tabula rasa, but rather builds on prior knowledge to facilitate learning. How prior knowledge influences the neural representation of novel associations remains unknown. Here, participants associated pairs of faces in two conditions: a famous, highly familiar face with a novel face or two novel faces while undergoing fMRI. We examine multivoxel activity patterns corresponding to individual faces before and after learning. The activity patterns representing members of famous-novel pairs becomes separated in the hippocampus, that is, more distinct from one another through learning, in striking contrast to paired novel faces that become similar. In the left inferior frontal gyrus, however, prior knowledge leads to integration, and in a specific direction: the representation of the novel face becomes similar to that of the famous face after learning, suggesting assimilation of new into old memories. We propose that hippocampal separation might resolve interference between existing and newly learned information, allowing cortical assimilation. Thus, associative learning with versus without prior knowledge relies on radically different computations.


Assuntos
Giro do Cíngulo/fisiologia , Hipocampo/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Assimetria Facial/fisiopatologia , Feminino , Humanos , Masculino , Memória , Rede Nervosa/fisiologia , Adulto Jovem
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