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1.
Neuropsychobiology ; : 1-12, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38574476

RESUMO

INTRODUCTION: Neurobiological dysfunction is associated with depression in children and adolescents. While research in adult depression suggests that inflammation may underlie the association between depression and brain alterations, it is unclear if altered levels of inflammatory markers provoke neurobiological dysfunction in early-onset depression. The aim of this scoping review was to provide an overview of existing literature investigating the potential interaction between neurobiological function and inflammation in depressed children and adolescents. METHODS: Systematic searches were conducted in six databases. Primary research studies that included measures of both neurobiological functioning and inflammation among children (≤18 years) with a diagnosis of depression were included. RESULTS: Four studies (240 participants; mean age 16.0 ± 0.6 years, 62% female) meeting inclusion criteria were identified. Studies primarily examined the inflammatory markers interleukin 6, tumor necrosis factor alpha, C-reactive protein, and interleukin 1 beta. Exploratory whole brain imaging and analysis as well as region of interest approaches focused on the anterior cingulate cortex, basal ganglia, and white matter tracts were conducted. Most studies found correlations between neurobiological function and inflammatory markers; however, depressive symptoms were not observed to moderate these effects. CONCLUSIONS: A small number of highly heterogeneous studies indicate that depression may not modulate the association between altered inflammation and neurobiological dysfunction in children and adolescents. Replication in larger samples using consistent methodological approaches (focus on specific inflammatory markers, examine certain brain areas) is needed to advance the knowledge of potential neuro-immune interactions early in the course of depression.

2.
Cognition ; 245: 105724, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38266352

RESUMO

Personality traits and affective states are associated with biases in facial emotion perception. However, the precise personality impairments and affective states that underlie these biases remain largely unknown. To investigate how relevant factors influence facial emotion perception and recollection, Experiment 1 employed an image reconstruction approach in which community-dwelling adults (N = 89) rated the similarity of pairs of facial expressions, including those recalled from memory. Subsequently, perception- and memory-based expression representations derived from such ratings were assessed across participants and related to measures of personality impairment, state affect, and visual recognition abilities. Impairment in self-direction and level of positive affect accounted for the largest components of individual variability in perception and memory representations, respectively. Additionally, individual differences in these representations were impacted by face recognition ability. In Experiment 2, adult participants (N = 81) rated facial image reconstructions derived in Experiment 1, revealing that individual variability was associated with specific visual face properties, such as expressiveness, representation accuracy, and positivity/negativity. These findings highlight and clarify the influence of personality, affective state, and recognition abilities on individual differences in the perception and recollection of facial expressions.


Assuntos
Emoções , Reconhecimento Facial , Adulto , Humanos , Personalidade , Reconhecimento Psicológico , Individualidade , Expressão Facial
3.
Artigo em Inglês | MEDLINE | ID: mdl-36703496

RESUMO

Associative memory deficits in aging are frequently characterized by false recognition of novel stimulus associations, particularly when stimuli are similar. Introducing distinctive stimuli, therefore, can help guide item differentiation in memory and can further our understanding of how age-related brain changes impact behavior. How older adults use different types of distinctive information to distinguish overlapping events in memory and to avoid false associative recognition is still unknown. To test this, we manipulated the distinctiveness of items from two stimulus categories, scenes and objects, across three conditions: (1) distinct scenes paired with similar objects, (2) similar scenes paired with distinct objects, and (3) similar scenes paired with similar objects. Young and older adults studied scene-object pairs and then made both remember/know judgments toward single items as well as associative memory judgments to old and novel scene-object pairs ("Were these paired together?"). Older adults showed intact single item recognition of scenes and objects, regardless of whether those objects and scenes were similar or distinct. In contrast, relative to younger adults, older adults showed elevated false recognition for scene-object pairs, even when the scenes were distinct. These age-related associative memory deficits, however, disappeared if the pair contained an object that was visually distinct. In line with neural evidence that hippocampal functioning and scene processing decline with age, these results suggest that older adults can rely on memory for distinct objects, but not for distinct scenes, to distinguish between memories with overlapping features.


Assuntos
Rememoração Mental , Reconhecimento Psicológico , Humanos , Idoso , Transtornos da Memória , Encéfalo , Envelhecimento
4.
Elife ; 122023 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-37313833

RESUMO

Neural models of approach-avoidance (AA) conflict behavior and its dysfunction have focused traditionally on the hippocampus, with the assumption that this medial temporal lobe (MTL) structure plays a ubiquitous role in arbitrating AA conflict. We challenge this perspective by using three different AA behavioral tasks in conjunction with optogenetics, to demonstrate that a neighboring region in male rats, perirhinal cortex, is also critically involved but only when conflicting motivational values are associated with objects and not contextual information. The ventral hippocampus, in contrast, was found not to be essential for object-associated AA conflict, suggesting its preferential involvement in context-associated conflict. We propose that stimulus type can impact MTL involvement during AA conflict and that a more nuanced understanding of MTL contributions to impaired AA behavior (e.g., anxiety) is required. These findings serve to expand upon the established functions of the perirhinal cortex while concurrently presenting innovative behavioral paradigms that permit the assessment of different facets of AA conflict behavior.


Assuntos
Córtex Perirrinal , Masculino , Ratos , Animais , Córtex Perirrinal/fisiologia , Roedores , Hipocampo/fisiologia , Lobo Temporal/fisiologia , Motivação
5.
J Cardiothorac Surg ; 18(1): 117, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37038197

RESUMO

BACKGROUND: While the pledget suture technique has been the standard for surgical aortic. valve replacement (AVR), discussion continues regarding the possibility of the nonpledget suture technique to produce superior structural and hemodynamic parameters. This study aims to assess the effectiveness of the figure-of-eight suture technique in AVR, as determined by the incidence of prosthesis-patient mismatch (PPM). METHODS: We reviewed records of patients (N = 629) who underwent a surgical AVR procedure between January 2011 and July 2018 at a single institution. Indexed effective orifice area values and PPM incidence were calculated from implanted valve size and patient body surface area. Incidence of none, moderate, and severe PPM was compared across AVR suture techniques. RESULTS: A total of 570 pledget and 59 figure-of-eight patients were compared for incidence of PPM. Patients who received AVR with the pledget suture technique had significantly lower echocardiographic measurements of baseline ejection fraction than patients who had received AVR with the figure-of-eight suture technique (p = 0.003). Patients who received the figure-of eight suture had a 14% decrease in moderate PPM compared to patients who received the pledget suture (p = 0.022). Patients who received the figure-of-eight suture also had a significantly higher rate of no PPM (p = 0.044). CONCLUSIONS: The use of the figure-of-eight suture technique in AVR can reduce the incidence of moderate PPM. While the pledget suture is the standard technique in AVR, the figure-of-eight suture technique may offer better structural and hemodynamic outcomes, especially for patients with a smaller aortic annulus.


Assuntos
Estenose da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Humanos , Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Estenose da Valva Aórtica/cirurgia , Resultado do Tratamento , Desenho de Prótese , Técnicas de Sutura
6.
Neuropsychologia ; 185: 108573, 2023 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-37119985

RESUMO

Damage to the medial temporal lobe (MTL), which is traditionally considered to subserve memory exclusively, has been reported to contribute to impaired face perception. However, it remains unknown how exactly such brain lesions may impact face representations and in particular facial shape and surface information, both of which are crucial for face perception. The present study employed a behavioral-based image reconstruction approach to reveal the pictorial representations of face perception in two amnesic patients: DA, who has an extensive bilateral MTL lesion that extends beyond the MTL in the right hemisphere, and BL, who has damage to the hippocampal dentate gyrus (DG). Both patients and their respective matched controls completed similarity judgments for pairs of faces, from which facial shape and surface features were subsequently derived and synthesized to create images of reconstructed facial appearance. Participants also completed a face oddity judgment task (FOJT) that has previously been shown to be sensitive to MTL cortical damage. While BL exhibited an impaired pattern of performance on the FOJT, DA demonstrated intact performance accuracy. Notably, the recovered pictorial content of faces was comparable between both patients and controls, although there was evidence for atypical face representations in BL particularly with regards to color. Our work provides novel insight into the face representations underlying face perception in two well-studied amnesic patients in the literature and demonstrates the applicability of the image reconstruction approach to individuals with brain damage.


Assuntos
Reconhecimento Facial , Humanos , Amnésia/diagnóstico por imagem , Amnésia/patologia , Lobo Temporal/patologia , Giro Para-Hipocampal , Processamento de Imagem Assistida por Computador
7.
Cereb Cortex ; 33(12): 7797-7815, 2023 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-36944537

RESUMO

The prefrontal cortex (PFC) has long been associated with arbitrating between approach and avoidance in the face of conflicting and uncertain motivational information, but recent work has also highlighted medial temporal lobe (MTL) involvement. It remains unclear, however, how the contributions of these regions differ in their resolution of conflict information and uncertainty. We designed an fMRI paradigm in which participants approached or avoided object pairs that differed by motivational conflict and outcome uncertainty (complete certainty vs. complete uncertainty). Behavioral data and decision-making parameters estimated using the hierarchical drift diffusion model revealed that participants' responding was driven by conflict rather than uncertainty. Our neural data suggest that PFC areas contribute to cognitive control during approach-avoidance conflict by potentially adjusting response caution and the strength of evidence generated towards either choice, with differential involvement of anterior cingulate cortex and dorsolateral prefrontal cortex. The MTL, on the other hand, appears to contribute to evidence generation, with the hippocampus linked to evidence accumulation for stimuli. Although findings within perirhinal cortex were comparatively equivocal, some evidence suggests contributions to perceptual representations, particularly under conditions of threat. Our findings provide evidence that MTL and PFC regions may contribute uniquely to arbitrating approach-avoidance conflict.


Assuntos
Hipocampo , Lobo Temporal , Humanos , Hipocampo/fisiologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Imageamento por Ressonância Magnética , Motivação
8.
PLoS One ; 18(1): e0280215, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36608051

RESUMO

Cognitive control is associated with impulsive and harmful behaviours, such as substance abuse and suicidal behaviours, as well as major depressive disorder (MDD) and borderline personality disorder (BPD). The association between MDD and BPD is partially explained by shared pathological personality traits, which may be underpinned by aspects of cognitive control, such as response inhibition. The neural basis of response inhibition in MDD and BPD is not fully understood and could illuminate factors that differentiate between the disorders and that underlie individual differences in cross-cutting pathological traits. In this study, we sought to explore the neural correlates of response inhibition in MDD and BPD, as well as the pathological personality trait domains contained in the ICD-11 personality disorder model. We measured functional brain activity underlying response inhibition on a Go/No-Go task using functional magnetic resonance imaging in 55 female participants recruited into three groups: MDD without comorbid BPD (n = 16), MDD and comorbid BPD (n = 18), and controls with neither disorder (n = 21). Whereas response-inhibition-related activation was observed bilaterally in frontoparietal cognitive control regions across groups, there were no group differences in activation or significant associations between activation in regions-of-interest and pathological personality traits. The findings highlight potential shared neurobiological substrates across diagnoses and suggest that the associations between individual differences in neural activation and pathological personality traits may be small in magnitude. Sufficiently powered studies are needed to elucidate the associations between the functional neural correlates of response inhibition and pathological personality trait domains.


Assuntos
Transtorno da Personalidade Borderline , Transtorno Depressivo Maior , Humanos , Feminino , Transtorno Depressivo Maior/psicologia , Transtorno da Personalidade Borderline/psicologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Transtornos da Personalidade/complicações , Comportamento Impulsivo
9.
J Psychiatr Res ; 155: 483-492, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36183602

RESUMO

Stress has a detrimental impact on memory, the hippocampus, and psychological health. Psychopathology research on stress has centered mainly on psychiatric diagnoses rather than symptom dimensions, and less attention has been given to the neurobiological factors through which stress might be translated into psychopathology. The present work investigates the transdiagnostic relationship of cumulative stress with episodic memory and the hippocampus (both structure and function) and explores the extent to which stress mediates the relationship between personality psychopathology and hippocampal size and activation. Cumulative lifetime stress was assessed in a sample of females recruited to vary in stress exposure and severity of personality psychopathology. Fifty-six participants completed subjective and objective tests of episodic memory, a T2-weighted high-resolution magnetic resonance imaging (MRI) scan of the medial-temporal lobe, and functional MRI (fMRI) scanning during a learning and recognition memory task. Higher cumulative stress was significantly related to memory complaints (but not episodic memory performance), lower bilateral hippocampal volume, and greater encoding-related hippocampal activation during the presentation of novel stimuli. Furthermore, cumulative stress significantly mediated the relationship between personality psychopathology and both hippocampal volume and activation, whereas alternative mediation models were not supported. The findings suggest that structural and functional activation differences in the hippocampus observed in case-control studies of psychiatric diagnoses may share cumulative stress as a common factor, which may mediate broadly reported relationships between psychopathology and hippocampal structure and function.


Assuntos
Hipocampo , Memória Episódica , Feminino , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Testes Neuropsicológicos , Personalidade , Transtornos da Personalidade/diagnóstico por imagem , Transtornos da Personalidade/etiologia , Lobo Temporal
10.
Artigo em Inglês | MEDLINE | ID: mdl-36082443

RESUMO

Temporal information, including information about temporal order and duration, is a fundamental component of event sequence memory. While previous research has demonstrated that aging can have a detrimental effect on memory for temporal order, there has been limited insight into the effect of aging on memory for durations, particularly within the context of sequences. In the current study, neurologically healthy young and older participants were administered two temporal match-mismatch tasks: one in which they were instructed on each trial to compare the temporal order or duration information of stimulus sequences presented first in a study phase and then, after a short delay, in a test phase (event sequence task); and a second in which participants were required to compare single durations or sequences of durations across study and test phases of each trial (pinwheel task). Consistent with the literature, the older participants were significantly poorer compared to their younger counterparts at making temporal order match-mismatch judgments in the event sequence task. In addition to this, data from both tasks suggested that the older adults were also less accurate at match-mismatch judgments based on duration information, with tentative evidence from the pinwheel task to suggest that this age-related effect was most prominent when the duration information was presented within a sequence. We suggest that age-related changes to medial temporal and frontal lobe function may contribute to changes in memory for temporal information in older adults, given the importance of these regions to event sequence memory.

11.
Nat Commun ; 13(1): 3349, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688838

RESUMO

The ability to resolve an approach-avoidance conflict is critical to adaptive behavior. The ventral CA3 (vCA3) and CA1 (vCA1) subfields of the ventral hippocampus (vHPC) have been shown to facilitate avoidance and approach behavior, respectively, in the face of motivational conflict, but the neural circuits by which this subfield-specific regulation is implemented is unknown. We demonstrate that two distinct pathways from these subfields to lateral septum (LS) contribute to this divergent control. In Long-Evans rats, chemogenetic inhibition of the vCA3- LS caudodorsal (cd) pathway potentiated approach towards a learned conflict-eliciting stimulus, while inhibition of the vCA1-LS rostroventral (rv) pathway potentiated approach non-specifically. Additionally, vCA3-LScd inhibited animals were less hesitant to explore food during environmental uncertainty, while the vCA1- LSrv inhibited animals took longer to initiate food exploration. These findings suggest that the vHPC influences multiple behavioral systems via differential projections to the LS, which in turn send inhibitory projections to motivational centres of the brain.


Assuntos
Hipocampo , Inibição Psicológica , Animais , Hipocampo/fisiologia , Vias Neurais/fisiologia , Ratos , Ratos Long-Evans
12.
Front Neurol ; 12: 674275, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34912281

RESUMO

Important information from the environment often arrives to the brain in temporally extended sequences. Language, music, actions, and complex events generally unfold over time. When such informational sequences exceed the limited capacity of working memory, the human brain relies on its ability to accumulate information in long-term memory over several encounters with a complex stimulus. A longstanding question in psychology and neuroscience is whether the neural structures associated with working memory storage-often viewed as capacity limited and temporary-have any builtin ability to store information across longer temporal delays. According to the classic Hebbian dual memory theory, temporally local "activity traces" underlie immediate perception and working memory, whereas "structural traces" undergird long-term learning. Here we examine whether brain structures known to be involved in working maintenance of auditory sequences, such as area Spt, also show evidence of memory persistence across trials. We used representational similarity analysis (RSA) and the Hebb repetition paradigm with supracapacity tonal sequences to test whether repeated sequences have distinguishable multivoxel activity patterns in the auditory-motor networks of the brain. We found that, indeed, area Spt and other nodes of the auditory dorsal stream show multivoxel patterns for tone sequences that become gradually more distinct with repetition during working memory for supracapacity tone-sequences. The findings suggest that the structures are important for working memory are not "blank slates," wiped clean from moment to moment, but rather encode information in a way can lead to cross-trial persistence.

13.
Neuron ; 109(17): 2643-2645, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34473951

RESUMO

In this issue of Neuron, Bonnen et al. (2021) use artificial neural networks to resolve a long-standing controversy surrounding the neurocognitive dichotomy between memory and perception. They show that the perirhinal cortex supports performance on tasks that cannot be solved by the ventral visual stream.


Assuntos
Aprendizado Profundo , Memória , Neurônios , Percepção , Lobo Temporal
14.
J Exp Psychol Hum Percept Perform ; 47(7): 977-991, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34323579

RESUMO

Extensive work has demonstrated an age-related decline in face recognition, but the nature and the extent of aging-related alterations in face representations remain unclear. Here, we address these issues using an image reconstruction approach to reveal the content of visual representations. Healthy young and older adults provided similarity judgments for pairs of face images. Facial shape and surface features were subsequently derived and combined into image reconstructions of facial appearance. Both objective and experimental evaluations revealed that reconstructions were successful for every participant. Critically, shape and surface properties, such as eye shape and skin tone, were less accurately represented in older than young individuals. Yet, age-related differences in face representations, though significant, were less pronounced than those due to individual variability. Our results provide novel insights into age-related changes in visual perception and demonstrate the utility of image reconstruction to uncovering internal representations across a variety of populations. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Reconhecimento Facial , Idoso , Envelhecimento , Face , Humanos , Processamento de Imagem Assistida por Computador , Percepção Visual
15.
J Affect Disord ; 284: 126-135, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592431

RESUMO

BACKGROUND: Many individuals with borderline personality disorder (BPD) perceive emotional expressions in faces intended to convey no emotion and display a heightened sensitivity to facial expressions conveying threat, such as fear. In BPD, the amygdala activates in response to ambiguous and threatening facial expressions, although the differential sensitivity of this brain region to higher and lower intensities of fearful expressions and the relationship of this neural activity to personality impairments have not yet been investigated. METHODS: In the present study, we examined brain activation during an implicit facial emotion task with neutral faces and fearful expressions displayed at 50% and 100% intensity in patients with BPD (n=45) and healthy controls (HC; n=25). RESULTS: On neutral faces, higher brain activation was found in BPD compared to HC in the right temporal pole, amygdala, hippocampus, pallidum, and orbitofrontal cortex, whereas no significant whole-brain group differences were observed for either intensity of fearful expressions. A region-of-interest analysis focused on the amygdala-hippocampal complex showed greater activation for neutral and 50%-intensity fearful faces in BPD. Severity of personality impairment in the domains of empathy and identity were associated with higher precuneus activity during neutral and 100%-fearful face processing. LIMITATIONS: Brain activation differences of this naturalistic severely ill inpatient sample may be influenced by comorbid Axis-I disorders often seen in samples of BPD. CONCLUSIONS: These findings suggest a heightened amygdala-hippocampal response to neutral faces and moderate-intensity fearful expressions in BPD, while self and interpersonal impairments are associated with task-based activations in regions implicated in self-referential processes.


Assuntos
Transtorno da Personalidade Borderline , Tonsila do Cerebelo , Emoções , Expressão Facial , Medo , Humanos , Imageamento por Ressonância Magnética
16.
Cereb Cortex ; 31(5): 2701-2719, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33429427

RESUMO

The rodent ventral and primate anterior hippocampus have been implicated in approach-avoidance (AA) conflict processing. It is unclear, however, whether this structure contributes to AA conflict detection and/or resolution, and if its involvement extends to conditions of AA conflict devoid of spatial/contextual information. To investigate this, neurologically healthy human participants first learned to approach or avoid single novel visual objects with the goal of maximizing earned points. Approaching led to point gain and loss for positive and negative objects, respectively, whereas avoidance had no impact on score. Pairs of these objects, each possessing nonconflicting (positive-positive/negative-negative) or conflicting (positive-negative) valences, were then presented during functional magnetic resonance imaging. Participants either made an AA decision to score points (Decision task), indicated whether the objects had identical or differing valences (Memory task), or followed a visual instruction to approach or avoid (Action task). Converging multivariate and univariate results revealed that within the medial temporal lobe, perirhinal cortex, rather than the anterior hippocampus, was predominantly associated with object-based AA conflict resolution. We suggest the anterior hippocampus may not contribute equally to all learned AA conflict scenarios and that stimulus information type may be a critical and overlooked determinant of the neural mechanisms underlying AA conflict behavior.


Assuntos
Aprendizagem da Esquiva , Comportamento de Escolha , Conflito Psicológico , Hipocampo/diagnóstico por imagem , Memória/fisiologia , Motivação , Córtex Perirrinal/diagnóstico por imagem , Lobo Temporal/diagnóstico por imagem , Adolescente , Adulto , Tomada de Decisões , Feminino , Neuroimagem Funcional , Hipocampo/fisiologia , Humanos , Aprendizagem/fisiologia , Imageamento por Ressonância Magnética , Masculino , Córtex Perirrinal/fisiologia , Lobo Temporal/fisiologia , Adulto Jovem
17.
Neuropsychopharmacology ; 46(3): 632-642, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33154580

RESUMO

Approach-avoidance conflict is induced when an organism encounters a stimulus that carries both positive and negative attributes. Accumulating evidence implicates the ventral hippocampus (VH) in the detection and resolution of approach-avoidance conflict, largely on the basis of maze-based tasks assaying innate and conditioned responses to situations of conflict. However, its role in discrete trial approach-avoidance decision-making has yet to be elucidated. In this study, we designed a novel cued operant conflict decision-making task in which rats were required to choose and respond for a low reward option or high reward option paired with varying shock intensities on a differential reinforcement of low rates of responding schedule. Post training, the VH was chemogenetically inhibited while animals performed the task with the usual outcomes delivered, and with the presentation of cues associated with the reward vs. conflict options only (extinction condition). We found that VH inhibition led to an avoidance of the conflict option and longer latency to choose this option when decision-making was being made on the basis of cues alone with no outcomes. Consistent with these findings, VH-inhibited animals spent more time in the central component of the elevated plus maze (EPM), indicating a potential deficit in decision-making under innate forms of approach-avoidance conflict. Taken together, these findings implicate the VH in cue-driven approach-avoidance decisions in the face of motivational conflict.


Assuntos
Aprendizagem da Esquiva , Sinais (Psicologia) , Animais , Tomada de Decisões , Hipocampo , Ratos , Recompensa
18.
J Neurosci ; 40(41): 7887-7901, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-32900835

RESUMO

The frontal cortex and temporal lobes together regulate complex learning and memory capabilities. Here, we collected resting-state functional and diffusion-weighted MRI data before and after male rhesus macaque monkeys received extensive training to learn novel visuospatial discriminations (reward-guided learning). We found functional connectivity changes in orbitofrontal, ventromedial prefrontal, inferotemporal, entorhinal, retrosplenial, and anterior cingulate cortices, the subicular complex, and the dorsal, medial thalamus. These corticocortical and thalamocortical changes in functional connectivity were accompanied by related white matter structural alterations in the uncinate fasciculus, fornix, and ventral prefrontal tract: tracts that connect (sub)cortical networks and are implicated in learning and memory processes in monkeys and humans. After the well-trained monkeys received fornix transection, they were impaired in learning new visuospatial discriminations. In addition, the functional connectivity profile that was observed after the training was altered. These changes were accompanied by white matter changes in the ventral prefrontal tract, although the integrity of the uncinate fasciculus remained unchanged. Our experiments highlight the importance of different communication relayed among corticocortical and thalamocortical circuitry for the ability to learn new visuospatial associations (learning-to-learn) and to make reward-guided decisions.SIGNIFICANCE STATEMENT Frontal neural networks and the temporal lobes contribute to reward-guided learning in mammals. Here, we provide novel insight by showing that specific corticocortical and thalamocortical functional connectivity is altered after rhesus monkeys received extensive training to learn novel visuospatial discriminations. Contiguous white matter fiber pathways linking these gray matter structures, namely, the uncinate fasciculus, fornix, and ventral prefrontal tract, showed structural changes after completing training in the visuospatial task. Additionally, different patterns of functional and structural connectivity are reported after removal of subcortical connections within the extended hippocampal system, via fornix transection. These results highlight the importance of both corticocortical and thalamocortical interactions in reward-guided learning in the normal brain and identify brain structures important for memory capabilities after injury.


Assuntos
Córtex Cerebral/fisiologia , Condicionamento Operante/fisiologia , Discriminação Psicológica/fisiologia , Vias Neurais/fisiologia , Tálamo/fisiologia , Substância Branca/fisiologia , Animais , Mapeamento Encefálico , Córtex Cerebral/diagnóstico por imagem , Fórnice/fisiologia , Macaca mulatta , Imageamento por Ressonância Magnética , Masculino , Memória/fisiologia , Vias Neurais/diagnóstico por imagem , Recompensa , Percepção Espacial/fisiologia , Tálamo/diagnóstico por imagem , Percepção Visual/fisiologia , Substância Branca/diagnóstico por imagem
19.
Trends Cogn Sci ; 24(9): 747-759, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32674958

RESUMO

Recent research has demonstrated that neural and behavioral data acquired in response to viewing face images can be used to reconstruct the images themselves. However, the theoretical implications, promises, and challenges of this direction of research remain unclear. We evaluate the potential of this research for elucidating the visual representations underlying face recognition. Specifically, we outline complementary and converging accounts of the visual content, the representational structure, and the neural dynamics of face processing. We illustrate how this research addresses fundamental questions in the study of normal and impaired face recognition, and how image reconstruction provides a powerful framework for uncovering face representations, for unifying multiple types of empirical data, and for facilitating both theoretical and methodological progress.


Assuntos
Reconhecimento Facial , Processamento de Imagem Assistida por Computador , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Reconhecimento Visual de Modelos
20.
J Affect Disord ; 274: 1041-1048, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663930

RESUMO

BACKGROUND: Borderline personality disorder (BPD) is associated with subjective reports of forgetfulness and deficits on tests of memory performance. However, it is not yet known whether individuals with BPD show different patterns of activation in the hippocampus during episodic memory encoding, especially for materials that are not emotionally-valenced. METHODS: Participants with BPD (n = 20) and non-psychiatric controls (n = 21) completed a memory encoding task in which they viewed scenes without emotional content during functional magnetic resonance imaging scans. Subsequently, they completed a recognition memory test outside of the scanner and neural activation during the presentation of successfully remembered scenes was contrasted with scenes that were subsequently forgotten. RESULTS: Controls exhibited significant left hippocampal activation during successful memory encoding, displaying greater activity during the presentation of subsequently remembered versus forgotten scenes, and the strength of this activation was related to their recognition memory performance. Although hippocampal activation was observed for the BPD group during successful memory encoding, it did not reach significance when implementing a non-parametric statistical approach. Additionally, individual hippocampal recruitment was not significantly correlated with recognition memory performance in the BPD group. The strength of this correlation, but not the overall magnitude of hippocampal activation, was significantly different between the groups. LIMITATIONS: Participants with BPD had comorbid psychiatric diagnoses and varied treatment histories. Whether patients and controls differentially perceived emotional content in the neutral scene memoranda was not tested. CONCLUSIONS: Memory problems in BPD may be partially explained by a disrupted relationship between hippocampal activation and successful memory encoding.


Assuntos
Transtorno da Personalidade Borderline , Cognição , Emoções , Hipocampo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética
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