Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20.854
Filtrar
1.
Behav Brain Res ; 438: 114165, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36270464

RESUMO

Although the use of transcranial electrical stimulation (tES) techniques on healthy population has been linked to facilitating language learning, studies on their effects on foreign language learning processes are scarce and results remain unclear. The objective of this study was to analyze whether tES enhances foreign language learning processes. Sixty-four healthy native Spanish-speaking participants were randomly assigned to four groups (transcranial direct current, transcranial random noise, tDCS-tRNS stimulation, or sham). They completed two intervention sessions with a two-week gap in between. During the first session the participants received stimulation (1.5 mA) while learning new English words and then performed recall and recognition tasks. Learning was assessed at follow-up, two weeks later. No differences in learning between groups were observed in the first session (F(1,61)= .86; p = .36). At follow-up, significantly higher learning accuracy was observed after tRNS compared to sham (p = .037). These results suggest that tRNS could be helpful in improving the processes involved in foreign language vocabulary learning.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Humanos , Estimulação Transcraniana por Corrente Contínua/métodos , Vocabulário , Aprendizagem/fisiologia , Rememoração Mental/fisiologia
2.
Neuropsychopharmacology ; 48(1): 168-185, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36180784

RESUMO

Emerging research on neuroplasticity processes in psychosis spectrum illnesses-from the synaptic to the macrocircuit levels-fill key gaps in our models of pathophysiology and open up important treatment considerations. In this selective narrative review, we focus on three themes, emphasizing alterations in spike-timing dependent and Hebbian plasticity that occur during adolescence, the critical period for prefrontal system development: (1) Experience-dependent dysplasticity in psychosis emerges from activity decorrelation within neuronal ensembles. (2) Plasticity processes operate bidirectionally: deleterious environmental and experiential inputs shape microcircuits. (3) Dysregulated plasticity processes interact across levels of scale and time and include compensatory mechanisms that have pathogenic importance. We present evidence that-given the centrality of progressive dysplastic changes, especially in prefrontal cortex-pharmacologic or neuromodulatory interventions will need to be supplemented by corrective learning experiences for the brain if we are to help people living with these illnesses to fully thrive.


Assuntos
Período Crítico Psicológico , Transtornos Psicóticos , Adolescente , Humanos , Plasticidade Neuronal/fisiologia , Aprendizagem/fisiologia , Neurônios/fisiologia
3.
Cognition ; 230: 105290, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36240613

RESUMO

Statistical learning relies on detecting the frequency of co-occurrences of items and has been proposed to be crucial for a variety of learning problems, notably to learn and memorize words from fluent speech. Endress and Johnson (2021) (hereafter EJ) recently showed that such results can be explained based on simple memory-less correlational learning mechanisms such as Hebbian Learning. Tovar and Westermann (2022) (hereafter TW) reproduced these results with a different Hebbian model. We show that the main differences between the models are whether temporal decay acts on both the connection weights and the activations (in TW) or only on the activations (in EJ), and whether interference affects weights (in TW) or activations (in EJ). Given that weights and activations are linked through the Hebbian learning rule, the networks behave similarly. However, in contrast to TW, we do not believe that neurophysiological data are relevant to adjudicate between abstract psychological models with little biological detail. Taken together, both models show that different memory-less correlational learning mechanisms provide a parsimonious account of Statistical Learning results. They are consistent with evidence that Statistical Learning might not allow learners to learn and retain words, and Statistical Learning might support predictive processing instead.


Assuntos
Aprendizagem , Fala , Humanos , Aprendizagem/fisiologia
4.
Neuropsychopharmacology ; 48(1): 113-120, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35810199

RESUMO

Activity-dependent synaptic plasticity is a ubiquitous property of the nervous system that allows neurons to communicate and change their connections as a function of past experiences. Through reweighting of synaptic strengths, the nervous system can remodel itself, giving rise to durable memories that create the biological basis for mental function. In healthy individuals, synaptic plasticity undergoes characteristic developmental and aging trajectories. Dysfunctional plasticity, in turn, underlies a wide spectrum of neuropsychiatric disorders including depression, schizophrenia, addiction, and posttraumatic stress disorder. From a mechanistic standpoint, synaptic plasticity spans the gamut of spatial and temporal scales, from microseconds to the lifespan, from microns to the entire nervous system. With the numbers and strengths of synapses changing on such wide scales, there is an important need to develop measurement techniques with complimentary sensitivities and a growing number of approaches are now being harnessed for this purpose. Through hemodynamic measures, structural and tracer imaging, and noninvasive neuromodulation, it is possible to image structural and functional changes that underlie synaptic plasticity and associated behavioral learning. Here we review the mechanisms of neural plasticity and the historical and future trends in techniques that allow imaging of synaptic changes that accompany psychiatric disorders, highlighting emerging therapeutics and the challenges and opportunities accompanying this burgeoning area of study.


Assuntos
Saúde Mental , Plasticidade Neuronal , Humanos , Plasticidade Neuronal/fisiologia , Sinapses/fisiologia , Neurônios/fisiologia , Aprendizagem/fisiologia
5.
Artigo em Inglês | MEDLINE | ID: mdl-36181957

RESUMO

Humans gain knowledge about threats not only from their own experiences but also from observing others' behavior. A neutral stimulus is associated with a threat stimulus for several times and the neutral stimulus will evoke fear responses, which is known as fear conditioning. When encountering a new event that is similar to one previously associated with a threat, one may feel afraid and produce fear responses. This is called fear generalization. Previous studies have mostly focused on fear conditioning and generalization based on direct learning, but few have explored how observational fear learning affects fear conditioning and generalization. To the best of our knowledge, no previous study has focused on the neural correlations of fear conditioning and generalization based on observational learning. In the present study, 58 participants performed a differential conditioning paradigm in which they learned the associations between neutral cues (i.e., geometric figures) and threat stimuli (i.e., electric shock). The learning occurred on their own (i.e., direct learning) and by observing other participant's responses (i.e., observational learning); the study used a within-subjects design. After each learning condition, a fear generalization paradigm was conducted by each participant independently while their behavioral responses (i.e., expectation of a shock) and electroencephalography (EEG) recordings or responses were recorded. The shock expectancy ratings showed that observational learning, compared to direct learning, reduced the differentiation between the conditioned threatening stimuli and safety stimuli and the increased shock expectancy to the generalization stimuli. The EEG indicated that in fear learning, threatening conditioned stimuli in observational and direct learning increased early discrimination (P1) and late motivated attention (late positive potential [LPP]), compared with safety conditioned stimuli. In fear generalization, early discrimination, late motivated attention, and orienting attention (alpha-event-related desynchronization [alpha-ERD]) to generalization stimuli were reduced in the observational learning condition. These findings suggest that compared to direct learning, observational learning reduces differential fear learning and increases the generalization of fear, and this might be associated with reduced discrimination and attentional function related to generalization stimuli.


Assuntos
Medo , Generalização Psicológica , Humanos , Medo/fisiologia , Generalização Psicológica/fisiologia , Condicionamento Clássico/fisiologia , Aprendizagem/fisiologia , Atenção
6.
J Exp Child Psychol ; 226: 105553, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36202012

RESUMO

Observational fear learning is common in children as they learn to fear by observing their parents. Although adaptive, it can also contribute to the development of fear-related psychopathologies such as anxiety disorders. Therefore, it is important to identify and study the factors that modulate children's sensitivity to observational fear learning. For instance, observational fear learning can be facilitated by the synchronization of biological systems between two people. In parent-child dyads, physiological concordance is important and varies according to the attachment relationship, among others. We investigated the joint effect of parent-child physiological concordance and attachment on observational fear learning in children. A total of 84 parent-child dyads participated in this study. Parents were filmed while exposed to a fear-conditioning protocol, where one stimulus was associated with a shock (CS+) and the other was not (CS-). This recording was then shown to the children (observational learning). Thereafter, both stimuli (CS+ and CS-) were presented to the children without any shock (direct expression test). For both the parent and child, skin conductance activity was recorded throughout the entire procedure. We measured physiological concordance between the parent's phasic skin conductance signal during conditioning and the child's signal during the observational learning stage. Children showing stronger concordance and a less secure relationship with their parent exhibited higher levels of fear to the CS+, as indicated by a heightened skin conductance response during the direct expression test. Thus, when children have an insecure relationship with their parent, strong physiological concordance may increase their sensitivity to observational fear learning.


Assuntos
Medo , Aprendizagem , Humanos , Medo/fisiologia , Aprendizagem/fisiologia , Pais , Relações Pais-Filho
7.
Behav Res Ther ; 159: 104223, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36327523

RESUMO

Insomnia is a common and impairing consequence of military deployment, but little is known about pre-deployment risk factors for post-deployment insomnia. Abnormal threat learning tendencies are commonly observed in individuals with insomnia and maladaptive responses to stress have been implicated in the development of insomnia, suggesting that threat learning could be an important risk factor for post-deployment insomnia. Here, we examined pre-deployment threat learning as a predictor of post-deployment insomnia and the potential mechanisms underlying this effect. Male servicemembers (N = 814) completed measures of insomnia, psychiatric symptoms, and a threat learning task before and after military deployment. Threat learning indices that differentiated participants with versus withoutinsomnia at post-deployment were tested as pre-deployment predictors of post-deployment insomnia. Post-deployment insomnia was linked to elevations on several threat learning indices at post-deployment, but only higher threat conditioning, as indexed by higher threat expectancy ratings to the danger cue, emerged as a pre-deployment predictor of post-deployment insomnia. This effect was independent of combat exposure levels and partially mediated by greater post-deployment nightmares. The tendency to acquire stronger expectations of aversive events following encounters with danger cues may increase risk for post-deployment insomnia, in part due to the development of more severe nightmares.


Assuntos
Militares , Distúrbios do Início e da Manutenção do Sono , Transtornos de Estresse Pós-Traumáticos , Masculino , Humanos , Distúrbios do Início e da Manutenção do Sono/complicações , Transtornos de Estresse Pós-Traumáticos/psicologia , Militares/psicologia , Sonhos , Aprendizagem/fisiologia
8.
Nature ; 611(7936): 554-562, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36323779

RESUMO

Learning-related changes in brain activity are thought to underlie adaptive behaviours1,2. For instance, the learning of a reward site by rodents requires the development of an over-representation of that location in the hippocampus3-6. How this learning-related change occurs remains unknown. Here we recorded hippocampal CA1 population activity as mice learned a reward location on a linear treadmill. Physiological and pharmacological evidence suggests that the adaptive over-representation required behavioural timescale synaptic plasticity (BTSP)7. BTSP is known to be driven by dendritic voltage signals that we proposed were initiated by input from entorhinal cortex layer 3 (EC3). Accordingly, the CA1 over-representation was largely removed by optogenetic inhibition of EC3 activity. Recordings from EC3 neurons revealed an activity pattern that could provide an instructive signal directing BTSP to generate the over-representation. Consistent with this function, our observations show that exposure to a second environment possessing a prominent reward-predictive cue resulted in both EC3 activity and CA1 place field density that were more elevated at the cue than at the reward. These data indicate that learning-related changes in the hippocampus are produced by synaptic plasticity directed by an instructive signal from the EC3 that seems to be specifically adapted to the behaviourally relevant features of the environment.


Assuntos
Região CA1 Hipocampal , Córtex Entorrinal , Aprendizagem , Neurônios , Animais , Camundongos , Região CA1 Hipocampal/citologia , Região CA1 Hipocampal/fisiologia , Córtex Entorrinal/fisiologia , Aprendizagem/fisiologia , Neurônios/fisiologia , Recompensa , Dendritos/fisiologia , Plasticidade Neuronal , Optogenética , Sinais (Psicologia) , Modelos Neurológicos
9.
J Neurosci ; 42(48): 9053-9068, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36344264

RESUMO

The function of long-term memory is not just to reminisce about the past, but also to make predictions that help us behave appropriately and efficiently in the future. This predictive function of memory provides a new perspective on the classic question from memory research of why we remember some things but not others. If prediction is a key outcome of memory, then the extent to which an item generates a prediction signifies that this information already exists in memory and need not be encoded. We tested this principle using human intracranial EEG as a time-resolved method to quantify prediction in visual cortex during a statistical learning task and link the strength of these predictions to subsequent episodic memory behavior. Epilepsy patients of both sexes viewed rapid streams of scenes, some of which contained regularities that allowed the category of the next scene to be predicted. We verified that statistical learning occurred using neural frequency tagging and measured category prediction with multivariate pattern analysis. Although neural prediction was robust overall, this was driven entirely by predictive items that were subsequently forgotten. Such interference provides a mechanism by which prediction can regulate memory formation to prioritize encoding of information that could help learn new predictive relationships.SIGNIFICANCE STATEMENT When faced with a new experience, we are rarely at a loss for what to do. Rather, because many aspects of the world are stable over time, we rely on past experiences to generate expectations that guide behavior. Here we show that these expectations during a new experience come at the expense of memory for that experience. From intracranial recordings of visual cortex, we decoded what humans expected to see next in a series of photographs based on patterns of neural activity. Photographs that generated strong neural expectations were more likely to be forgotten in a later behavioral memory test. Prioritizing the storage of experiences that currently lead to weak expectations could help improve these expectations in future encounters.


Assuntos
Memória Episódica , Córtex Visual , Masculino , Feminino , Humanos , Aprendizagem/fisiologia , Córtex Visual/fisiologia , Rememoração Mental/fisiologia , Memória de Longo Prazo
10.
PLoS One ; 17(11): e0277793, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36399451

RESUMO

Vicarious learning, i.e. learning through observing others rather than through one's own experiences, is an integral skill of social species. The aim of this study was to assess the causal role of affect sharing, an important aspect of empathy, in vicarious fear learning. N = 39 participants completed a vicarious Pavlovian fear conditioning paradigm. In the learning stage, they watched another person-the demonstrator-responding with distress when receiving electric shocks to a color cue (conditioned stimulus; CS+; a different color served as CS-). In the subsequent test stage, an increased skin conductance response (SCR) to the CS+ presented in the absence of the demonstrator indexed vicarious fear learning. Each participant completed this paradigm under two different hypnotic suggestions, which were administered to induce high or low affect sharing with the demonstrator in the learning stage, following a counterbalanced within-subject design. In the learning stage, high affect sharing resulted in stronger unconditioned SCR, increased eye gaze toward the demonstrator's face, and higher self-reported unpleasantness while witnessing the demonstrator's distress. In the test stage, participants showed a stronger conditioned fear response (SCR) when they had learned under high, compared to low, affect sharing. In contrast, participants' declarative memory of how many shocks the demonstrator had received with each cue was not influenced by the affect sharing manipulation. These findings demonstrate that affect sharing is involved in enhancing vicarious fear learning, and thus advance our understanding of the role of empathy, and more generally emotion, in social observational learning.


Assuntos
Condicionamento Clássico , Medo , Humanos , Medo/psicologia , Condicionamento Clássico/fisiologia , Aprendizagem/fisiologia , Empatia , Fixação Ocular
11.
Elife ; 112022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36373657

RESUMO

How dynamic interactions between nervous system regions in mammals performs online motor control remains an unsolved problem. In this paper, we show that feedback control is a simple, yet powerful way to understand the neural dynamics of sensorimotor control. We make our case using a minimal model comprising spinal cord, sensory and motor cortex, coupled by long connections that are plastic. It succeeds in learning how to perform reaching movements of a planar arm with 6 muscles in several directions from scratch. The model satisfies biological plausibility constraints, like neural implementation, transmission delays, local synaptic learning and continuous online learning. Using differential Hebbian plasticity the model can go from motor babbling to reaching arbitrary targets in less than 10 min of in silico time. Moreover, independently of the learning mechanism, properly configured feedback control has many emergent properties: neural populations in motor cortex show directional tuning and oscillatory dynamics, the spinal cord creates convergent force fields that add linearly, and movements are ataxic (as in a motor system without a cerebellum).


Assuntos
Modelos Neurológicos , Movimento , Animais , Retroalimentação , Movimento/fisiologia , Aprendizagem/fisiologia , Cerebelo/fisiologia , Mamíferos
12.
PLoS Comput Biol ; 18(11): e1010628, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36399437

RESUMO

Artificial neural networks overwrite previously learned tasks when trained sequentially, a phenomenon known as catastrophic forgetting. In contrast, the brain learns continuously, and typically learns best when new training is interleaved with periods of sleep for memory consolidation. Here we used spiking network to study mechanisms behind catastrophic forgetting and the role of sleep in preventing it. The network could be trained to learn a complex foraging task but exhibited catastrophic forgetting when trained sequentially on different tasks. In synaptic weight space, new task training moved the synaptic weight configuration away from the manifold representing old task leading to forgetting. Interleaving new task training with periods of off-line reactivation, mimicking biological sleep, mitigated catastrophic forgetting by constraining the network synaptic weight state to the previously learned manifold, while allowing the weight configuration to converge towards the intersection of the manifolds representing old and new tasks. The study reveals a possible strategy of synaptic weights dynamics the brain applies during sleep to prevent forgetting and optimize learning.


Assuntos
Aprendizagem , Redes Neurais de Computação , Aprendizagem/fisiologia , Sono , Encéfalo
13.
Int J Psychophysiol ; 182: 240-247, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36372210

RESUMO

Observational threat learning is an indirect pathway to learn about what is safe versus dangerous. Visual gaze patterns may be an important measure to understand the underlying mechanisms of social threat learning. However, little research has considered this type of learning or attention allocation during observational learning, and even less has examined it across development. The study examined visual gaze patterns during observational threat acquisition amongst adolescents and adults. Ninety-three adolescents (13-17 years) and 78 adults (18-34 years) underwent a differential observational acquisition task by watching a video wherein a learning model was presented with colored bells. One bell (conditioned stimulus, CS+) was associated with an electric stimulation to the learning model's arm (social unconditioned stimulus, social US), while the other bell was not (CS-). Eye tracking was used during each trial. First, all participants, regardless of age, fixated longer on the face of the learning model when the CS+ was presented than when the CS- was presented. Second, adolescents averted their gaze from the learning model's face when the learning model received an electrical stimulation, whereas adults fixated more on the learning model's face when the stimulation was administered. Finally, adolescents understood the CS+-US contingency less than adults, stemming from the different gaze pattern for the age groups to the social US. Results replicate previous findings in adults and extend them to adolescents, emphasizing the importance of the learning model's facial expressions in conveying information on what is safe versus dangerous in the environment. Moreover, results showed developmental differences in gaze patterns during observational threat learning; this translated into poorer understanding of the CS+-US association amongst adolescents.


Assuntos
Condicionamento Clássico , Medo , Adolescente , Adulto , Humanos , Atenção/fisiologia , Condicionamento Clássico/fisiologia , Expressão Facial , Medo/fisiologia , Aprendizagem/fisiologia , Adulto Jovem
14.
Trends Neurosci ; 45(12): 884-898, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36404455

RESUMO

Diverse inhibitory neurons in the mammalian brain shape circuit connectivity and dynamics through mechanisms of synaptic plasticity. Inhibitory plasticity can establish excitation/inhibition (E/I) balance, control neuronal firing, and affect local calcium concentration, hence regulating neuronal activity at the network, single neuron, and dendritic level. Computational models can synthesize multiple experimental results and provide insight into how inhibitory plasticity controls circuit dynamics and sculpts connectivity by identifying phenomenological learning rules amenable to mathematical analysis. We highlight recent studies on the role of inhibitory plasticity in modulating excitatory plasticity, forming structured networks underlying memory formation and recall, and implementing adaptive phenomena and novelty detection. We conclude with experimental and modeling progress on the role of interneuron-specific plasticity in circuit computation and context-dependent learning.


Assuntos
Plasticidade Neuronal , Neurônios , Humanos , Animais , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Aprendizagem/fisiologia , Mamíferos
15.
Elife ; 112022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36374181

RESUMO

To adapt to a changing world, we must be able to switch between rules already learned and, at other times, learn rules anew. Often we must do both at the same time, switching between known rules while also constantly re-estimating them. Here, we show these two processes, rule switching and rule learning, rely on distinct but intertwined computations, namely fast inference and slower incremental learning. To this end, we studied how monkeys switched between three rules. Each rule was compositional, requiring the animal to discriminate one of two features of a stimulus and then respond with an associated eye movement along one of two different response axes. By modeling behavior, we found the animals learned the axis of response using fast inference (rule switching) while continuously re-estimating the stimulus-response associations within an axis (rule learning). Our results shed light on the computational interactions between rule switching and rule learning, and make testable neural predictions for these interactions.


Assuntos
Aprendizagem , Animais , Aprendizagem/fisiologia
16.
Nat Commun ; 13(1): 6729, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36344524

RESUMO

The hippocampus has been a focus of memory research since H.M's surgery abolished his ability to form new memories, yet its mechanistic role in memory remains debated. Here, we identify a candidate memory mechanism: an anticipatory hippocampal "convergence state", observed while awaiting valuable information, and which predicts subsequent learning. During fMRI, participants viewed trivia questions eliciting high or low curiosity, followed seconds later by its answer. We reasoned that encoding success requires a confluence of conditions, so that hippocampal states more conducive to memory formation should converge in state space. To operationalize convergence of neural states, we quantified the typicality of multivoxel patterns in the medial temporal lobes during anticipation and encoding of trivia answers. We found that the typicality of anticipatory hippocampal patterns increased during high curiosity. Crucially, anticipatory hippocampal pattern typicality increased with dopaminergic midbrain activation and uniquely accounted for the association between midbrain activation and subsequent recall. We propose that hippocampal convergence states may complete a cascade from motivation and midbrain activation to memory enhancement, and may be a general predictor of memory formation.


Assuntos
Hipocampo , Mesencéfalo , Humanos , Hipocampo/fisiologia , Mesencéfalo/fisiologia , Aprendizagem/fisiologia , Lobo Temporal/fisiologia , Rememoração Mental , Imageamento por Ressonância Magnética
17.
Commun Biol ; 5(1): 1241, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376497

RESUMO

The feedback people receive on their behavior shapes the process of belief formation and self-efficacy in mastering a particular task. However, the neural and computational mechanisms of how the subjective value of self-efficacy beliefs, and the corresponding affect, influence the learning process remain unclear. We investigated these mechanisms during self-efficacy belief formation using fMRI, pupillometry, and computational modeling, and by analyzing individual differences in affective experience. Biases in the formation of self-efficacy beliefs were associated with affect, pupil dilation, and neural activity within the anterior insula, amygdala, ventral tegmental area/ substantia nigra, and mPFC. Specifically, neural and pupil responses mapped the valence of the prediction errors in correspondence with individuals' experienced affective states and learning biases during self-efficacy belief formation. Together with the functional connectivity dynamics of the anterior insula within this network, our results provide evidence for neural and computational mechanisms of how we arrive at affected beliefs.


Assuntos
Mapeamento Encefálico , Imageamento por Ressonância Magnética , Humanos , Mapeamento Encefálico/métodos , Aprendizagem/fisiologia , Emoções , Substância Negra
18.
Cell Rep ; 41(8): 111700, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36417882

RESUMO

Decades of work propose that hippocampal activity supports internal representation of learned experiences and contexts, allowing individuals to form long-term memories and quickly adapt behavior to changing environments. However, recent studies insinuate hippocampal representations can drift over time, raising the question: how could the hippocampus hold stable memories when activity of its neuronal maps fluctuates? We hypothesized that task-dependent hippocampal maps set by learning rules and structured attention stabilize as a function of behavioral performance. To test this, we imaged hippocampal CA1 pyramidal neurons during learning and memory recall phases of a new task where mice use odor cues to navigate between two reward zones. Across learning, both orthogonal and overlapping task-dependent place maps form rapidly, discriminating trial context with strong correlation to behavioral performance. Once formed, task-selective place maps show increased long-term stability during memory recall phases. We conclude that memory demand and attention stabilize hippocampal activity to maintain contextually rich spatial representations.


Assuntos
Células de Lugar , Camundongos , Animais , Memória/fisiologia , Aprendizagem/fisiologia , Hipocampo/fisiologia , Células Piramidais/fisiologia
19.
J Cogn Neurosci ; 35(1): 74-89, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36306242

RESUMO

Prior animal and human studies have shown that post-encoding reinstatement plays an important role in organizing the temporal sequence of unfolding episodes in memory. Here, we investigated whether post-encoding reinstatement serves to promote the encoding of "one-shot" episodic learning beyond the temporal structure in humans. In Experiment 1, participants encoded sequences of pictures depicting unique and meaningful episodic-like events. We used representational similarity analysis on scalp EEG recordings during encoding and found evidence of rapid picture-elicited EEG pattern reinstatement at episodic offset (around 500 msec post-episode). Memory reinstatement was not observed between successive elements within an episode, and the degree of memory reinstatement at episodic offset predicted later recall for that episode. In Experiment 2, participants encoded a shuffled version of the picture sequences from Experiment 1, rendering each episode meaningless to the participant but temporally structured as in Experiment 1, and we found no evidence of memory reinstatement at episodic offset. These results suggest that post-encoding memory reinstatement is akin to the rapid formation of unique and meaningful episodes that unfold over time.


Assuntos
Memória Episódica , Humanos , Rememoração Mental/fisiologia , Aprendizagem/fisiologia , Eletroencefalografia/métodos
20.
Exp Brain Res ; 240(12): 3141-3152, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36241746

RESUMO

Existing methods for measuring implicit sequence-learning consciousness are conducted offline. Based on the traditional measurement of cued-generation task, this study implemented an online measurement method by converting a generation task into a forced-choice task to observe the dynamic changes of consciousness in the implicit sequence-learning process. In this study, we compared the performance of online measurement task and traditional sequence-learning tasks in 31 university students. The results revealed that the online indicators were significantly correlated with classic consciousness indicators and typical ERP components of consciousness. Without affecting the development of consciousness, the online measurement indicators were found to promptly and effectively reflect the gradually changing progression of consciousness in implicit sequence learning.


Assuntos
Estado de Consciência , Aprendizagem Seriada , Análise e Desempenho de Tarefas , Humanos , Estado de Consciência/fisiologia , Sinais (Psicologia) , Aprendizagem/fisiologia , Tempo de Reação/fisiologia , Aprendizagem Seriada/fisiologia , Internet , Estudantes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...