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1.
Elife ; 112022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35642599

RESUMO

Detection of objects that move in a scene is a fundamental computation performed by the visual system. This computation is greatly complicated by observer motion, which causes most objects to move across the retinal image. How the visual system detects scene-relative object motion during self-motion is poorly understood. Human behavioral studies suggest that the visual system may identify local conflicts between motion parallax and binocular disparity cues to depth and may use these signals to detect moving objects. We describe a novel mechanism for performing this computation based on neurons in macaque middle temporal (MT) area with incongruent depth tuning for binocular disparity and motion parallax cues. Neurons with incongruent tuning respond selectively to scene-relative object motion, and their responses are predictive of perceptual decisions when animals are trained to detect a moving object during self-motion. This finding establishes a novel functional role for neurons with incongruent tuning for multiple depth cues.


Assuntos
Percepção de Movimento , Animais , Sinais (Psicologia) , Movimento (Física) , Percepção de Movimento/fisiologia , Lobo Temporal/fisiologia , Disparidade Visual
2.
PLoS One ; 17(6): e0270592, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35749536

RESUMO

Episodic memory is supported by a distributed network of brain regions, and this complex network of regions does not operate in isolation. To date, neuroscience research in this area has typically focused on the activation levels in specific regions or pairwise connectivity between such regions. However, research has yet to investigate how the complex interactions of structural brain networks influence episodic memory abilities. We applied graph theory methods to diffusion-based anatomical networks in order to examine the structural architecture of the medial temporal lobe needed to support effective episodic memory functioning. We examined the relationship between performance on tests of verbal and non-verbal episodic memory with node strength, which indexes how well connected a brain region is in the network. Findings mapped onto the Posterior Medial memory system, subserved by the parahippocampal cortex and overlapped with findings of previous studies of episodic memory employing different methodologies. This expands our current understanding by providing independent evidence for the importance of identified regions and suggesting the particular manner in which these regions support episodic memory.


Assuntos
Memória Episódica , Encéfalo/fisiologia , Mapeamento Encefálico , Imageamento por Ressonância Magnética , Rememoração Mental/fisiologia , Lobo Temporal/fisiologia
3.
PLoS Comput Biol ; 18(6): e1009995, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35679333

RESUMO

To characterize the functional role of the left-ventral occipito-temporal cortex (lvOT) during reading in a quantitatively explicit and testable manner, we propose the lexical categorization model (LCM). The LCM assumes that lvOT optimizes linguistic processing by allowing fast meaning access when words are familiar and filtering out orthographic strings without meaning. The LCM successfully simulates benchmark results from functional brain imaging described in the literature. In a second evaluation, we empirically demonstrate that quantitative LCM simulations predict lvOT activation better than alternative models across three functional magnetic resonance imaging studies. We found that word-likeness, assumed as input into a lexical categorization process, is represented posteriorly to lvOT, whereas a dichotomous word/non-word output of the LCM could be localized to the downstream frontal brain regions. Finally, training the process of lexical categorization resulted in more efficient reading. In sum, we propose that word recognition in the ventral visual stream involves word-likeness extraction followed by lexical categorization before one can access word meaning.


Assuntos
Mapeamento Encefálico , Lobo Occipital , Simulação por Computador , Imageamento por Ressonância Magnética , Lobo Occipital/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Lobo Temporal/fisiologia
4.
Cortex ; 153: 55-65, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35597051

RESUMO

Previous brain functional specialization evidence has shown that both aware and unaware visual processing of manipulable objects activate left premotor, parietal, and posterior temporal cortices, which are thought to constitute object-directed action and object-function processing streams. An open question is whether, both under supraliminal and subliminal processing conditions, there is directional spread of activation along these functional streams, leading to causal inter-regional connectivity effects. In this study, we used Dynamic Causal Modelling to estimate the effective connectivity influences within the premotor-parieto-temporal network, as a function of factorial contrasts for Manipulability (manipulable vs non-manipulable objects) and Perceptual Awareness (above vs below perceptual threshold). We modeled forward and backward connections originating from visual area V4, as a region underlying object texture segregation, and spreading through the left premotor-parieto-temporal network. Both above and below perceptual threshold, the visual processing of manipulable objects was associated with a specific increase of reciprocal effective connectivity coupling among left premotor-parieto-temporal regions. Aware and unaware manipulable object processing differed from each other for their distinct patterns of top-down activation enhancement exerted, in the former case, by left premotor-parieto-temporal regions on area V4 and, in the latter case, by left premotor on temporal regions. Although it is only under aware processing conditions that effective connectivity in the action representation system may promote object visual contour segregation in area V4, our results suggest that the encoding of object-action and object-function information can occur through left-hemispheric premotor, parietal, and temporal causal interdependencies, even when the object is not consciously perceived.


Assuntos
Mapeamento Encefálico , Córtex Visual , Mapeamento Encefálico/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Lobo Temporal/fisiologia , Percepção Visual/fisiologia
5.
Hippocampus ; 32(7): 481-487, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35579307

RESUMO

A necessary condition for forming episodic memories is the construction of specific episodes demarcated from other episodes in space and time. Evidence from studies of episodic memory formation using rodent models suggest that the medial temporal lobe (MTL) supports the representation of boundary information. Building on recent work using human microelectrode recordings as well, we hypothesized of human MTL neurons with firing rates sensitive to episodic boundary information. We identified 27 episodic boundary neurons out of 736 single neurons recorded across 27 subjects. Firing of these neurons increased at the beginning and end of mnemonically relevant episodes in the free recall task. We distinguish episodic boundary neurons from a population of ramping neurons (n = 58), which are time-sensitive neurons whose activity provides complementary information during episodic representation. Episodic boundary neurons exhibited a U-shaped activity pattern demonstrating increased activity after both beginning and end boundaries of encoding and retrieval epochs. We also describe evidence that the firing of boundary neurons within episodic boundaries is organized by hippocampal theta oscillations, using spike-field coherence metrics.


Assuntos
Memória Episódica , Lobo Temporal , Hipocampo/fisiologia , Humanos , Rememoração Mental/fisiologia , Neurônios , Lobo Temporal/fisiologia
6.
J Neurosci ; 42(23): 4619-4628, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35508382

RESUMO

Speech is often degraded by environmental noise or hearing impairment. People can compensate for degradation, but this requires cognitive effort. Previous research has identified frontotemporal networks involved in effortful perception, but materials in these works were also less intelligible, and so it is not clear whether activity reflected effort or intelligibility differences. We used functional magnetic resonance imaging to assess the degree to which spoken sentences were processed under distraction and whether this depended on speech quality even when intelligibility of degraded speech was matched to that of clear speech (close to 100%). On each trial, male and female human participants either attended to a sentence or to a concurrent multiple object tracking (MOT) task that imposed parametric cognitive load. Activity in bilateral anterior insula reflected task demands; during the MOT task, activity increased as cognitive load increased, and during speech listening, activity increased as speech became more degraded. In marked contrast, activity in bilateral anterior temporal cortex was speech selective and gated by attention when speech was degraded. In this region, performance of the MOT task with a trivial load blocked processing of degraded speech, whereas processing of clear speech was unaffected. As load increased, responses to clear speech in these areas declined, consistent with reduced capacity to process it. This result dissociates cognitive control from speech processing; substantially less cognitive control is required to process clear speech than is required to understand even very mildly degraded, 100% intelligible speech. Perceptual and control systems clearly interact dynamically during real-world speech comprehension.SIGNIFICANCE STATEMENT Speech is often perfectly intelligible even when degraded, for example, by background sound, phone transmission, or hearing loss. How does degradation alter cognitive demands? Here, we use fMRI to demonstrate a novel and critical role for cognitive control in the processing of mildly degraded but perfectly intelligible speech. We compare speech that is matched for intelligibility but differs in putative control demands, dissociating cognitive control from speech processing. We also impose a parametric cognitive load during perception, dissociating processes that depend on tasks from those that depend on available capacity. Our findings distinguish between frontal and temporal contributions to speech perception and reveal a hidden cost to processing mildly degraded speech, underscoring the importance of cognitive control for everyday speech comprehension.


Assuntos
Perda Auditiva , Percepção da Fala , Cognição , Feminino , Humanos , Masculino , Ruído , Inteligibilidade da Fala/fisiologia , Percepção da Fala/fisiologia , Lobo Temporal/fisiologia
7.
Sci Rep ; 12(1): 8628, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35606516

RESUMO

Rapid categorization of visual objects is critical for comprehending our complex visual world. The role of individual cortical neurons and neural populations in categorizing visual objects during passive vision has previously been studied. However, it is unclear whether and how perceptually guided behaviors affect the encoding of stimulus categories by neural population activity in the higher visual cortex. Here we studied the activity of the inferior temporal (IT) cortical neurons in macaque monkeys during both passive viewing and categorization of ambiguous body and object images. We found enhanced category information in the IT neural population activity during the correct, but not wrong, trials of the categorization task compared to the passive task. This encoding enhancement was task difficulty dependent with progressively larger values in trials with more ambiguous stimuli. Enhancement of IT neural population information for behaviorally relevant stimulus features suggests IT neural networks' involvement in perceptual decision-making behavior.


Assuntos
Lobo Temporal , Córtex Visual , Animais , Macaca , Neurônios/fisiologia , Estimulação Luminosa/métodos , Lobo Temporal/fisiologia
8.
Neuropsychologia ; 171: 108239, 2022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35427602

RESUMO

Previous studies revealed a close relationship between retrieval ability and creative thinking; however, it is still unclear what processes of creative thinking are influenced by retrieval ability. This study applied a novel task paradigm to distinguish between different processes of creative thinking. We used functional near-infrared spectroscopy (fNIRS) to explore the differences of cortical activation and functional connectivity in the prefrontal cortex (PFC), temporoparietal junction (TPJ) and temporal cortex between high (HRA) and low (LRA) retrieval ability groups during creating original ideas (CO) and recalling original ideas (RO) tasks. The behaviour results revealed that in the CO task, the HRA group performed better than the LRA group on fluency, flexibility, and originality. Importantly, the fNIRS results further indicated that the HRA group exhibited higher activation of the l-TPJ, l-STG, l-MTG, r-FPC, r-DLPFC than the LRA group during the CO task. Moreover, the HRA group exhibited higher activation of the bilateral TPJ, l-STG, l-MTG, r-DLPFC, and r-FPC in the CO task than in the RO task, and the LRA group exhibited higher activation of the l-STG in the CO task than in the RO task. The functional connectivity between the PFC and IFG, TPJ, and MTG of the HRA group was significantly stronger than that of the LRA group in both the CO and RO tasks. The findings suggest that high retrieval ability could facilitate the generation of creative ideas by facilitating the retrieval of novel information and suppression of common information compared to low retrieval ability. This study provides neural evidence for the effect of different levels of retrieval ability on creative thinking.


Assuntos
Córtex Pré-Frontal , Lobo Temporal , Criatividade , Humanos , Rememoração Mental , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia
9.
Hum Brain Mapp ; 43(10): 3293-3305, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35384132

RESUMO

Enhanced visual cortex activation by negative compared to neutral stimuli is often attributed to modulating feedback from the amygdala, but evidence from lesion studies is scarce, particularly regarding differential effects of left and right amygdala lesions. Therefore, we compared visual cortex activation by negative and neutral complex scenes in an event-related fMRI study between 40 patients with unilateral temporal lobe resection (TLR; 19 left [lTLR], 21 right [rTLR]), including the amygdala, and 20 healthy controls. We found preserved hemodynamic emotion modulation of visual cortex in rTLR patients and only subtle reductions in lTLR patients. In contrast, rTLR patients showed a significant decrease in visual cortex activation irrespective of picture content. In line with this, healthy controls showed small emotional modulation of the left amygdala only, while their right amygdala was activated equally by negative and neutral pictures. Correlations of activation in amygdala and visual cortex were observed for both negative and neutral pictures in the controls. In both patient groups, this relationship was attenuated ipsilateral to the TLR. Our results support the notion of reentrant mechanisms between amygdala and visual cortex and suggest laterality differences in their emotion-specificity. While right medial temporal lobe structures including the amygdala seem to influence visual processing in general, the left medial temporal lobe appears to contribute specifically to emotion processing. Still, effects of left TLR on visual emotion processing were relatively subtle. Therefore, hemodynamic correlates of visual emotion processing are likely supported by a distributed cerebral network, challenging an amygdalocentric view of emotion processing.


Assuntos
Tonsila do Cerebelo , Lobo Temporal , Tonsila do Cerebelo/diagnóstico por imagem , Tonsila do Cerebelo/fisiologia , Tonsila do Cerebelo/cirurgia , Emoções/fisiologia , Hemodinâmica , Humanos , Imageamento por Ressonância Magnética/métodos , Estimulação Luminosa/métodos , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia , Lobo Temporal/cirurgia
10.
Neuroimage ; 255: 119204, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35427771

RESUMO

Visual working memory refers to the temporary maintenance and manipulation of task-related visual information. Recent debate on the underlying neural substrates of visual working memory has focused on the delay period of relevant tasks. Persistent neural activity throughout the delay period has been recognized as a correlate of working memory, yet regions demonstrating sustained hemodynamic responses show inconsistency across individual studies. To develop a more precise understanding of delay-period activations during visual working memory, we conducted a coordinate-based meta-analysis on 30 fMRI experiments involving 515 healthy adults with a mean age of 25.65 years. The main analysis revealed a widespread frontoparietal network associated with delay-period activity, as well as activation in the right inferior temporal cortex. These findings were replicated using different meta-analytical algorithms and were shown to be robust against between-study heterogeneity and publication bias. Further meta-analyses on different subgroups of experiments with specific task demands and stimulus types revealed similar delay-period networks, with activations distributed across the frontal and parietal cortices. The roles of prefrontal regions, posterior parietal regions, and inferior temporal areas are reviewed and discussed in the context of content-specific storage. We conclude that cognitive operations that occur during the unfilled delay period in visual working memory tasks can be flexibly expressed across a frontoparietal-temporal network depending on experimental parameters.


Assuntos
Imageamento por Ressonância Magnética , Memória de Curto Prazo , Adulto , Mapeamento Encefálico , Humanos , Memória de Curto Prazo/fisiologia , Lobo Parietal/fisiologia , Lobo Temporal/fisiologia
11.
Sci Rep ; 12(1): 5735, 2022 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-35388106

RESUMO

We often fail to recall another person's name. Proper names might be more difficult to memorize and retrieve than other pieces of knowledge, such as one's profession because they are processed differently in the brain. Neuroimaging and neuropsychological studies associate the bilateral anterior temporal lobes (ATL) in the retrieval of proper names and other person-related knowledge. Specifically, recalling a person's name is thought to be supported by the left ATL, whereas recalling specific information such as a person's occupation is suggested to be subserved by the right ATL. To clarify and further explore the causal relationship between both ATLs and proper name retrieval, we stimulated these regions with anodal, cathodal and sham transcranial direct current stimulation (tDCS) while the participants memorized surnames (e.g., Mr. Baker) and professions (e.g., baker) presented with a person's face. The participants were then later asked to recall the surname and the profession. Left ATL anodal stimulation resulted in higher intrusion errors for surnames than sham, whereas right ATL anodal stimulation resulted in higher overall intrusion errors, both, surnames and professions, compared to cathodal stimulation. Cathodal stimulation of the left and right ATL had no significant effect on surname and profession recall. The results indicate that the left ATL plays a role in recalling proper names. On the other hand, the specific role of the right ATL remaines to be explored.


Assuntos
Nomes , Estimulação Transcraniana por Corrente Contínua , Face , Humanos , Rememoração Mental/fisiologia , Lobo Temporal/fisiologia
12.
PLoS Biol ; 20(3): e3001565, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35239647

RESUMO

A change of mind in response to social influence could be driven by informational conformity to increase accuracy, or by normative conformity to comply with social norms such as reciprocity. Disentangling the behavioural, cognitive, and neurobiological underpinnings of informational and normative conformity have proven elusive. Here, participants underwent fMRI while performing a perceptual task that involved both advice-taking and advice-giving to human and computer partners. The concurrent inclusion of 2 different social roles and 2 different social partners revealed distinct behavioural and neural markers for informational and normative conformity. Dorsal anterior cingulate cortex (dACC) BOLD response tracked informational conformity towards both human and computer but tracked normative conformity only when interacting with humans. A network of brain areas (dorsomedial prefrontal cortex (dmPFC) and temporoparietal junction (TPJ)) that tracked normative conformity increased their functional coupling with the dACC when interacting with humans. These findings enable differentiating the neural mechanisms by which different types of conformity shape social changes of mind.


Assuntos
Giro do Cíngulo/fisiologia , Lobo Parietal/fisiologia , Córtex Pré-Frontal/fisiologia , Desempenho Psicomotor/fisiologia , Lobo Temporal/fisiologia , Adulto , Algoritmos , Tomada de Decisões/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Modelos Neurológicos , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiologia , Estimulação Luminosa/métodos , Conformidade Social , Adulto Jovem
13.
Science ; 375(6585): eabj5861, 2022 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-35271334

RESUMO

We present a unique, extensive, and open synaptic physiology analysis platform and dataset. Through its application, we reveal principles that relate cell type to synaptic properties and intralaminar circuit organization in the mouse and human cortex. The dynamics of excitatory synapses align with the postsynaptic cell subclass, whereas inhibitory synapse dynamics partly align with presynaptic cell subclass but with considerable overlap. Synaptic properties are heterogeneous in most subclass-to-subclass connections. The two main axes of heterogeneity are strength and variability. Cell subclasses divide along the variability axis, whereas the strength axis accounts for substantial heterogeneity within the subclass. In the human cortex, excitatory-to-excitatory synaptic dynamics are distinct from those in the mouse cortex and vary with depth across layers 2 and 3.


Assuntos
Neocórtex/fisiologia , Vias Neurais , Neurônios/fisiologia , Sinapses/fisiologia , Transmissão Sináptica , Adulto , Animais , Conjuntos de Dados como Assunto , Potenciais Pós-Sinápticos Excitadores , Feminino , Humanos , Potenciais Pós-Sinápticos Inibidores , Masculino , Camundongos , Camundongos Transgênicos , Modelos Neurológicos , Neocórtex/citologia , Lobo Temporal/citologia , Lobo Temporal/fisiologia , Córtex Visual/citologia , Córtex Visual/fisiologia
14.
Nat Neurosci ; 25(3): 358-368, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35260859

RESUMO

While experience is continuous, memories are organized as discrete events. Cognitive boundaries are thought to segment experience and structure memory, but how this process is implemented remains unclear. We recorded the activity of single neurons in the human medial temporal lobe (MTL) during the formation and retrieval of memories with complex narratives. Here, we show that neurons responded to abstract cognitive boundaries between different episodes. Boundary-induced neural state changes during encoding predicted subsequent recognition accuracy but impaired event order memory, mirroring a fundamental behavioral tradeoff between content and time memory. Furthermore, the neural state following boundaries was reinstated during both successful retrieval and false memories. These findings reveal a neuronal substrate for detecting cognitive boundaries that transform experience into mnemonic episodes and structure mental time travel during retrieval.


Assuntos
Memória Episódica , Cognição , Humanos , Imageamento por Ressonância Magnética , Transtornos da Memória , Rememoração Mental/fisiologia , Neurônios , Lobo Temporal/fisiologia
15.
Neuroimage ; 252: 119041, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35231630

RESUMO

Our mental representation of egocentric space is influenced by the disproportionate sensory perception of the body. Previous studies have focused on the neural architecture for egocentric representations within the visual field. However, the space representation underlying the body is still unclear. To address this problem, we applied both functional Magnitude Resonance Imaging (fMRI) and Magnetoencephalography (MEG) to a spatial-memory paradigm by using a virtual environment in which human participants remembered a target location left, right, or back relative to their own body. Both experiments showed larger involvement of the frontoparietal network in representing a retrieved target on the left/right side than on the back. Conversely, the medial temporal lobe (MTL)-parietal network was more involved in retrieving a target behind the participants. The MEG data showed an earlier activation of the MTL-parietal network than that of the frontoparietal network during retrieval of a target location. These findings suggest that the parietal cortex may represent the entire space around the self-body by coordinating two distinct brain networks.


Assuntos
Percepção Espacial , Campos Visuais , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Rememoração Mental/fisiologia , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/fisiologia , Percepção Espacial/fisiologia , Lobo Temporal/fisiologia
16.
Neuropsychologia ; 169: 108192, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35245528

RESUMO

Animate and inanimate objects elicit distinct response patterns in the human ventral temporal cortex (VTC), but the exact features driving this distinction are still poorly understood. One prominent feature that distinguishes typical animals from inanimate objects and that could potentially explain the animate-inanimate distinction in the VTC is the presence of a face. In the current fMRI study, we investigated this possibility by creating a stimulus set that included animals with faces, faceless animals, and inanimate objects, carefully matched in order to minimize other visual differences. We used both searchlight-based and ROI-based representational similarity analysis (RSA) to test whether the presence of a face explains the animate-inanimate distinction in the VTC. The searchlight analysis revealed that when animals with faces were removed from the analysis, the animate-inanimate distinction almost disappeared. The ROI-based RSA revealed a similar pattern of results, but also showed that, even in the absence of faces, information about agency (a combination of animal's ability to move and think) is present in parts of the VTC that are sensitive to animacy. Together, these analyses showed that animals with faces do elicit a stronger animate/inanimate response in the VTC, but that faces are not necessary in order to observe high-level animacy information (e.g., agency) in parts of the VTC. A possible explanation could be that this animacy-related activity is driven not by faces per se, or the visual features of faces, but by other factors that correlate with face presence, such as the capacity for self-movement and thought. In short, the VTC might treat the face as a proxy for agency, a ubiquitous feature of familiar animals.


Assuntos
Mapeamento Encefálico , Reconhecimento Visual de Modelos , Animais , Cabeça , Humanos , Imageamento por Ressonância Magnética/métodos , Reconhecimento Visual de Modelos/fisiologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia
17.
J Neurosci Methods ; 375: 109577, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35339507

RESUMO

BACKGROUND: Detecting dynamic targets from complex visual scenes is an important problem in real world. However, the cognitive mechanism accounting for dynamic visual target detection remains unclear. NEW METHOD: Herein, we aim to explore the cognitive process of dynamic visual target detection from searching to spotting and provide more concrete evidence for cognitive studies related to target detection. Cortical source responses with high spatiotemporal resolution were reconstructed from scalp EEG signals. Then, time-varying cortical networks were built using adaptive directed transfer function to explore the cognitive processes while detecting the dynamic visual target. RESULTS: The experimental results demonstrated that the dynamic visual target detection enhanced the activation in both the visual and attention networks. Specially, the information flow from the middle occipital gyrus (MOG) mainly contributed to the position function, whereas the activation of the prefrontal cortex (PFC) reflected spatial attention maintenance. CONCLUSION: The left "frontal-central-parietal" network played as a leading information source in dynamic target detection tasks. These findings provide new insights into cognitive processes of dynamic visual target detection.


Assuntos
Mapeamento Encefálico , Encéfalo , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Eletroencefalografia/métodos , Córtex Pré-Frontal/fisiologia , Lobo Temporal/fisiologia
18.
Hum Brain Mapp ; 43(9): 2782-2800, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35274789

RESUMO

Scanning young children while they watch short, engaging, commercially-produced movies has emerged as a promising approach for increasing data retention and quality. Movie stimuli also evoke a richer variety of cognitive processes than traditional experiments, allowing the study of multiple aspects of brain development simultaneously. However, because these stimuli are uncontrolled, it is unclear how effectively distinct profiles of brain activity can be distinguished from the resulting data. Here we develop an approach for identifying multiple distinct subject-specific Regions of Interest (ssROIs) using fMRI data collected during movie-viewing. We focused on the test case of higher-level visual regions selective for faces, scenes, and objects. Adults (N = 13) were scanned while viewing a 5.6-min child-friendly movie, as well as a traditional localizer experiment with blocks of faces, scenes, and objects. We found that just 2.7 min of movie data could identify subject-specific face, scene, and object regions. While successful, movie-defined ssROIS still showed weaker domain selectivity than traditional ssROIs. Having validated our approach in adults, we then used the same methods on movie data collected from 3 to 12-year-old children (N = 122). Movie response timecourses in 3-year-old children's face, scene, and object regions were already significantly and specifically predicted by timecourses from the corresponding regions in adults. We also found evidence of continued developmental change, particularly in the face-selective posterior superior temporal sulcus. Taken together, our results reveal both early maturity and functional change in face, scene, and object regions, and more broadly highlight the promise of short, child-friendly movies for developmental cognitive neuroscience.


Assuntos
Mapeamento Encefálico , Filmes Cinematográficos , Retenção Psicológica , Adulto , Mapeamento Encefálico/métodos , Criança , Pré-Escolar , Humanos , Imageamento por Ressonância Magnética/métodos , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia
19.
Neuroimage ; 254: 119123, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35321857

RESUMO

The involvement of the medial temporal lobe (MTL) in working memory is controversially discussed. Recent findings suggest that persistent neural firing in the hippocampus during maintenance in verbal working memory is associated with workload. Here, we recorded single neuron firing in 13 epilepsy patients (7 male) while they performed a visual working memory task. The number of colored squares in the stimulus set determined the workload of the trial. Performance was almost perfect for low workload (1 and 2 squares) and dropped at high workload (4 and 6 squares), suggesting that high workload exceeded working memory capacity. We identified maintenance neurons in MTL neurons that showed persistent firing during the maintenance period. More maintenance neurons were found in the hippocampus for trials with correct compared to incorrect performance. Maintenance neurons increased and decreased firing in the hippocampus and increased firing in the entorhinal cortex for high compared to low workload. Population firing predicted workload particularly during the maintenance period. Prediction accuracy of workload based on single-trial activity during maintenance was strongest for neurons in the entorhinal cortex and hippocampus. The data suggest that persistent neural firing in the MTL reflects a domain-general process of maintenance supporting performance and workload of multiple items in working memory below and beyond working memory capacity. Persistent neural firing during maintenance in the entorhinal cortex may be associated with its preference to process visual-spatial arrays.


Assuntos
Memória de Curto Prazo , Carga de Trabalho , Córtex Entorrinal/fisiologia , Feminino , Hipocampo/fisiologia , Humanos , Masculino , Memória de Curto Prazo/fisiologia , Neurônios/fisiologia , Lobo Temporal/fisiologia
20.
Curr Biol ; 32(7): 1457-1469.e4, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35172128

RESUMO

Understanding complex human brain functions is critically informed by studying such functions during development. Here, we addressed a major gap in models of human memory by leveraging rare direct electrophysiological recordings from children and adolescents. Specifically, memory relies on interactions between the medial temporal lobe (MTL) and prefrontal cortex (PFC), and the maturation of these interactions is posited to play a key role in supporting memory development. To understand the nature of MTL-PFC interactions, we examined subdural recordings from MTL and PFC in 21 neurosurgical patients aged 5.9-20.5 years as they performed an established scene memory task. We determined signatures of memory formation by comparing the study of subsequently recognized to forgotten scenes in single trials. Results establish that MTL and PFC interact via two distinct theta mechanisms, an ∼3-Hz oscillation that supports amplitude coupling and slows down with age and an ∼7-Hz oscillation that supports phase coupling and speeds up with age. Slow and fast theta interactions immediately preceding scene onset further explained age-related differences in recognition performance. Last, with additional diffusion imaging data, we linked both functional mechanisms to the structural maturation of the cingulum tract. Our findings establish system-level dynamics of memory formation and suggest that MTL and PFC interact via increasingly dissociable mechanisms as memory improves across development.


Assuntos
Córtex Pré-Frontal , Lobo Temporal , Adolescente , Criança , Humanos , Imageamento por Ressonância Magnética , Rede Nervosa/fisiologia , Córtex Pré-Frontal/fisiologia , Reconhecimento Psicológico , Lobo Temporal/fisiologia , Ritmo Teta/fisiologia
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