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1.
Am J Obstet Gynecol ; 229(3): 294.e1-294.e14, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36863645

RESUMO

BACKGROUND: Preeclampsia, a hypertensive pregnancy disorder, is a leading cause of maternal and fetal morbidity and mortality, with remote cardio- and cerebrovascular implications. After preeclampsia, women may report serious disabling cognitive complaints, especially involving executive function, but the extent and time course of these complaints are unknown. OBJECTIVE: This study aimed to determine the impact of preeclampsia on perceived maternal cognitive functioning decades after pregnancy. STUDY DESIGN: This study is part of a cross-sectional case-control study named Queen of Hearts (ClinicalTrials.gov Identifier: NCT02347540), a collaboration study of 5 tertiary referral centers within the Netherlands investigating long-term effects of preeclampsia. Eligible participants were female patients aged ≥18 years after preeclampsia and after normotensive pregnancy between 6 months and 30 years after their first (complicated) pregnancy. Preeclampsia was defined as new-onset hypertension after 20 weeks of gestation along with proteinuria, fetal growth restriction, or other maternal organ dysfunction. Women with a history of hypertension, autoimmune disease, or kidney disease before their first pregnancy were excluded. Attenuation of higher-order cognitive functions, that is, executive function, was measured with the Behavior Rating Inventory of Executive Function for Adults. Crude and covariate-adjusted absolute and relative risks of clinical attenuation over time after (complicated) pregnancy were determined with moderated logistic and log-binomial regression. RESULTS: This study included 1036 women with a history of preeclampsia and 527 women with normotensive pregnancies. Regarding overall executive function, 23.2% (95% confidence interval, 19.0-28.1) of women experienced clinically relevant attenuation after preeclampsia, as opposed to 2.2% (95% confidence interval, 0.8-6.0) of controls immediately after childbirth (adjusted relative risk, 9.20 [95% confidence interval, 3.33-25.38]). Group differences diminished yet remained statistically significant (P < .05) at least 19 years postpartum. Regardless of history of preeclampsia, women with lower educational attainment, mood or anxiety disorders, or obesity were especially at risk. Neither severity of preeclampsia, multiple gestation, method of delivery, preterm birth, nor perinatal death was related to overall executive function. CONCLUSION: After preeclampsia, women were 9 times more likely to experience clinical attenuation of higher-order cognitive functions as opposed to after normotensive pregnancy. Despite overall steady improvement, elevated risks persisted over decades after childbirth.


Assuntos
Hipertensão , Pré-Eclâmpsia , Nascimento Prematuro , Adulto , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Estudos de Casos e Controles , Cognição , Estudos Transversais , Pré-Eclâmpsia/epidemiologia , Adolescente
2.
Psychol Res ; 87(2): 583-597, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35482089

RESUMO

We memorize our daily life experiences, which are often multisensory in nature, by segmenting them into distinct event models, in accordance with perceived contextual or situational changes. However, very little is known about how multisensory boundaries affect segmentation, as most studies have focused on unisensory (visual or audio) segmentation. In three experiments, we investigated the effect of multisensory boundaries on segmentation in memory and perception. In Experiment 1, participants encoded lists of pictures while audio and visual contexts changed synchronously or asynchronously. After each list, we tested recognition and temporal associative memory for pictures that were encoded in the same audio-visual context or that crossed a synchronous or an asynchronous multisensory change. We found no effect of multisensory synchrony for recognition memory: synchronous and asynchronous changes similarly impaired recognition for pictures encoded at those changes, compared to pictures encoded further away from those changes. Multisensory synchrony did affect temporal associative memory, which was worse for pictures encoded at synchronous than at asynchronous changes. Follow up experiments showed that this effect was not due to the higher dimensionality of multisensory over unisensory contexts (Experiment 2), nor that it was due to the temporal unpredictability of contextual changes inherent to Experiment 1 (Experiment 3). We argue that participants formed situational expectations through multisensory synchronicity, such that synchronous multisensory changes deviated more strongly from those expectations than asynchronous changes. We discuss our findings in light of supportive and conflicting findings of uni- and multi-sensory segmentation.


Assuntos
Percepção Auditiva , Percepção Visual , Humanos , Estimulação Acústica , Estimulação Luminosa , Reconhecimento Psicológico
3.
Neurobiol Learn Mem ; 182: 107444, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33895350

RESUMO

Neural oscillations in the theta range (4-8 Hz) are thought to underlie associative memory function in the hippocampal-cortical network. While there is ample evidence supporting a role of theta oscillations in animal and human memory, most evidence is correlational. Non-invasive brain stimulation (NIBS) can be employed to modulate cortical oscillatory activity to influence brain activity, and possibly modulate deeper brain regions, such as hippocampus, through strong and reliable cortico-hippocampal functional connections. We applied focal transcranial alternating current stimulation (tACS) at 6 Hz over left parietal cortex to modulate brain activity in the putative cortico-hippocampal network to influence associative memory encoding. After encoding and brain stimulation, participants completed an associative memory and a perceptual recognition task. Results showed that theta tACS significantly decreased associative memory performance but did not affect perceptual memory performance. These results show that parietal theta tACS modulates associative processing separately from perceptual processing, and further substantiate the hypothesis that theta oscillations are implicated in the cortico-hippocampal network and associative encoding.


Assuntos
Aprendizagem por Associação/fisiologia , Hipocampo/fisiologia , Memória/fisiologia , Lobo Parietal/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Percepção Visual/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Vias Neurais/fisiologia , Percepção/fisiologia , Ritmo Teta , Adulto Jovem
4.
Neuroimage ; 223: 117319, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32882376

RESUMO

There is increasing evidence that the hippocampus is involved in language production and verbal communication, although little is known about its possible role. According to one view, hippocampus contributes semantic memory to spoken language. Alternatively, hippocampus is involved in the processing the (mis)match between expected sensory consequences of speaking and the perceived speech feedback. In the current study, we re-analysed functional magnetic resonance (fMRI) data of two overt picture-naming studies to test whether hippocampus is involved in speech production and, if so, whether the results can distinguish between a "pure memory" versus a "prediction" account of hippocampal involvement. In both studies, participants overtly named pictures during scanning while hearing their own speech feedback unimpededly or impaired by a superimposed noise mask. Results showed decreased hippocampal activity when speech feedback was impaired, compared to when feedback was unimpeded. Further, we found increased functional coupling between auditory cortex and hippocampus during unimpeded speech feedback, compared to impaired feedback. Finally, we found significant functional coupling between a hippocampal/supplementary motor area (SMA) interaction term and auditory cortex, anterior cingulate cortex and cerebellum during overt picture naming, but not during listening to one's own pre-recorded voice. These findings indicate that hippocampus plays a role in speech production that is in accordance with a "prediction" view of hippocampal functioning.


Assuntos
Hipocampo/fisiologia , Percepção da Fala/fisiologia , Estimulação Acústica , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Mascaramento Perceptivo/fisiologia , Fala
5.
Hippocampus ; 30(9): 926-937, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32275344

RESUMO

The hippocampus and dorsal striatum are both associated with temporal processing, but they are thought to play distinct roles. The hippocampus has been reported to contribute to storing temporal structure of events in memory, whereas the striatum contributes to temporal motor preparation and reward anticipation. Here, we asked whether the striatum cooperates with the hippocampus in processing the temporal context of memorized visual associations. In our task, participants were trained to implicitly form temporal expectations for one of two possible time intervals associated to specific cue-target associations, and subsequently were scanned using ultra-high-field 7T functional magnetic resonance imaging. During scanning, learned temporal expectations could be violated when the pairs were presented at either the associated or not-associated time intervals. When temporal expectations were met during testing trials, activity in left and right hippocampal subfields and right putamen decreased, compared to when temporal expectations were not met. Further, psycho-physiological interactions showed that functional connectivity between left hippocampal subfields and caudate decreased when temporal expectations were not met. Our results indicate that the hippocampus and striatum cooperate to process implicit temporal expectation from mnemonic associations. Our findings provide further support for a hippocampal-striatal network in temporal associative processing.


Assuntos
Aprendizagem por Associação/fisiologia , Corpo Estriado/fisiologia , Hipocampo/fisiologia , Memória/fisiologia , Motivação/fisiologia , Rede Nervosa/fisiologia , Adulto , Corpo Estriado/diagnóstico por imagem , Feminino , Hipocampo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/diagnóstico por imagem , Fatores de Tempo , Adulto Jovem
6.
Mem Cognit ; 48(5): 691-703, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32103427

RESUMO

Associative memory has been increasingly investigated in immersive virtual reality (VR) environments, but conditions that enable physical exploration remain heavily under-investigated. To address this issue, we designed two museum rooms in VR throughout which participants could physically walk (i.e., high immersive and interactive fidelity). Participants were instructed to memorize all room details, which each contained nine paintings and two stone sculptures. On a subsequent old/new recognition task, we examined to what extent shared associated context (i.e., spatial boundaries, ordinal proximity) and physically travelled distance between paintings facilitated recognition of paintings from the museum rooms. Participants more often correctly recognized a sequentially probed old painting when the directly preceding painting was encoded within the same room or in a proximal position, relative to those encoded across rooms or in a distal position. A novel finding was that sequentially probed paintings from the same room were also recognized better when the physically travelled spatial or temporal distance between the probed paintings was shorter, as compared with longer distances. Taken together, our results in highly immersive VR support the notion that spatiotemporal context facilitates recognition of associated event content.


Assuntos
Memória Episódica , Realidade Virtual , Adolescente , Adulto , Simulação por Computador , Feminino , Humanos , Masculino , Reconhecimento Psicológico , Adulto Jovem
7.
J Cogn Neurosci ; 31(5): 625-638, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30240311

RESUMO

The dorsal attention network (DAN) is known to be involved in shifts of spatial attention or in orienting. However, the involvement of each hemisphere in shifts to either hemifield is still a matter of debate. In this study, interindividual hemifield-specific attentional benefits in RTs were correlated with cue-related BOLD responses specific to directive cues in the left and right frontal and posterior nodes of the DAN, measured in a Spatial Orienting Paradigm. The pattern of correlations was analyzed with respect to its fit with three existing hypotheses of spatial attention control: the contralateral, right dominance, and hybrid hypotheses. Results showed that activation in frontal and parietal nodes of the DAN could explain a significant proportion of the interindividual variance in attentional benefits. Although we found that benefits in the right hemifield correlated with cue-related activity in the left, as well as the right, DAN and that the pattern of correlations fit best with the right dominance hypothesis, there were no significant correlations between left benefits and activation in the right (as well as left) DAN, which precludes the conclusion that our data support the right dominance hypothesis and might instead point toward a potential qualitative difference between leftward and rightward shifts of attention. In conclusion, this study demonstrates that behavioral effects of orienting can be linked to activation changes in the DAN, and it raises new questions with respect to the involvement of the frontal and parietal nodes in each hemisphere in hemifield-specific orienting.


Assuntos
Atenção/fisiologia , Sinais (Psicologia) , Lobo Frontal/fisiologia , Lateralidade Funcional , Lobo Parietal/fisiologia , Processamento Espacial/fisiologia , Adolescente , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiologia , Tempo de Reação , Adulto Jovem
8.
Eur J Neurosci ; 48(7): 2585-2598, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29389039

RESUMO

The appropriate definition and scaling of the magnitude of electroencephalogram (EEG) oscillations is an underdeveloped area. The aim of this study was to optimize the analysis of resting EEG alpha magnitude, focusing on alpha peak frequency and nonlinear transformation of alpha power. A family of nonlinear transforms, Box-Cox transforms, were applied to find the transform that (a) maximized a non-disputed effect: the increase in alpha magnitude when the eyes are closed (Berger effect), and (b) made the distribution of alpha magnitude closest to normal across epochs within each participant, or across participants. The transformations were performed either at the single epoch level or at the epoch-average level. Alpha peak frequency showed large individual differences, yet good correspondence between various ways to estimate it in 2 min of eyes-closed and 2 min of eyes-open resting EEG data. Both alpha magnitude and the Berger effect were larger for individual alpha than for a generic (8-12 Hz) alpha band. The log-transform on single epochs (a) maximized the t-value of the contrast between the eyes-open and eyes-closed conditions when tested within each participant, and (b) rendered near-normally distributed alpha power across epochs and participants, thereby making further transformation of epoch averages superfluous. The results suggest that the log-normal distribution is a fundamental property of variations in alpha power across time in the order of seconds. Moreover, effects on alpha power appear to be multiplicative rather than additive. These findings support the use of the log-transform on single epochs to achieve appropriate scaling of alpha magnitude.


Assuntos
Ritmo alfa/fisiologia , Encéfalo/fisiologia , Eletroencefalografia , Movimentos Oculares/fisiologia , Adulto , Análise de Dados , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Descanso/fisiologia
9.
Learn Mem ; 24(4): 158-161, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28298554

RESUMO

The extent to which time is represented in memory remains underinvestigated. We designed a time paired associate task (TPAT) in which participants implicitly learned cue-time-target associations between cue-target pairs and specific cue-target intervals. During subsequent memory testing, participants showed increased accuracy of identifying matching cue-target pairs if the time interval during testing matched the implicitly learned interval. A control experiment showed that participants had no explicit knowledge about the cue-time associations. We suggest that "elapsed time" can act as a temporal mnemonic associate that can facilitate retrieval of events associated in memory.


Assuntos
Aprendizagem por Associação/fisiologia , Rememoração Mental/fisiologia , Tempo de Reação/fisiologia , Sinais (Psicologia) , Feminino , Humanos , Masculino , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa , Fatores de Tempo , Adulto Jovem
10.
Eur Arch Psychiatry Clin Neurosci ; 267(6): 551-565, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28039553

RESUMO

Emotion instability in borderline personality disorder (BPD) has been associated with an impaired fronto-limbic inhibitory network. However, functional connectivity (FC) underlying altered emotion regulation in BPD has yet to be established. Here, we used resting-state fMRI to investigate enduring effects of effortful emotion regulation on the amygdala intrinsic FC in BPD. In this multicenter study, resting-state fMRI was acquired before and after an emotion regulation task in 48 BPD patients and 39 non-patient comparison individuals. The bilateral amygdalae were used as a seed in the whole-brain FC analysis and two-way mixed ANOVA to test whether BPD patients exhibited weaker post-task increase in the amygdala intrinsic FC with the prefrontal cortex (PFC), compared to non-patients. Subsequently, we explored whether the results are common for personality disorders characterized by emotional problems, using additional data of 21 cluster-C personality disorder patients. In contrast to non-patients, BPD patients failed to show increased post-task amygdala resting-state FC with the medial, dorsolateral, ventrolateral PFC, and superior temporal gyrus, but surprisingly exhibited decreased FC with the posterior cingulate cortex and increased FC with the superior parietal lobule. In BPD patients, the emotion regulation task failed to increase resting-state amygdala FC with brain regions essential for effortful emotion regulation, which suggests: (a) altered cognitive control typically used to indirectly alleviate distress by reinterpreting the meaning of emotional stimuli; (b) impaired direct regulation of emotional responses, which might be common for personality disorders;


Assuntos
Tonsila do Cerebelo/fisiopatologia , Transtorno da Personalidade Borderline/fisiopatologia , Conectoma/métodos , Emoções/fisiologia , Córtex Pré-Frontal/fisiopatologia , Autocontrole , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Transtorno da Personalidade Borderline/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Córtex Pré-Frontal/diagnóstico por imagem , Adulto Jovem
11.
Eur J Neurosci ; 40(7): 3128-35, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24989884

RESUMO

The apolipoprotein E ε4 (ApoE ε4) allele not only represents the strongest single genetic risk factor for sporadic Alzheimer's disease, but also imposes independent effects on brain function in healthy individuals where it has been shown to promote subtle memory deficits and altered intrinsic functional brain network connectivity. Based on previous work showing a potential relevance of the default mode network (DMN) functional connectivity for episodic memory function, we hypothesized that the ApoE ε4 genotype would affect memory performance via modulation of the DMN. We assessed 63 healthy individuals (50-80 years old), of which 20 carried the ε4 allele. All participants underwent resting-state functional magnetic resonance imaging (fMRI), high-resolution 3D anatomical MRI imaging and neuropsychological assessment. Functional connectivity analysis of resting-state activity was performed with a predefined seed region located in the left posterior cingulate cortex (PCC), a core region of the DMN. ApoE ε4 carriers performed significantly poorer than non-carriers in wordlist recognition and cued recall. Furthermore, ε4 carriers showed increased connectivity relative to ε4 non-carriers between the PCC seed region and left-hemispheric middle temporal gyrus (MTG). There was a positive correlation between recognition memory scores and resting-state connectivity in the left MTG in ε4 carriers. These results can be interpreted as compensatory mechanisms strengthening the cross-links between DMN core areas and cortical areas involved in memory processing.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Giro do Cíngulo/fisiologia , Reconhecimento Psicológico/fisiologia , Lobo Temporal/fisiologia , Idoso , Encéfalo/fisiologia , Mapeamento Encefálico , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Rede Nervosa/fisiologia , Testes Neuropsicológicos , Descanso , Fatores de Risco
12.
BMJ Open ; 14(3): e077534, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38443087

RESUMO

INTRODUCTION: Pre-eclampsia is a hypertensive disorder affecting up to 8% of pregnancies. After pre-eclampsia, women are at increased risk of cognitive problems, and cerebrovascular and cardiovascular disorders. These sequelae could result from microvascular dysfunction persisting after pre-eclampsia. This study will explore differences in cerebral and myocardial microvascular function between women after pre-eclampsia and women after normotensive gestation. We hypothesise that pre-eclampsia alters cerebral and myocardial microvascular functions, which in turn are related to diminished cognitive and cardiac performance. METHODS AND ANALYSIS: The cross-sectional 'DEcreased Cognitive functiON, NEurovascular CorrelaTes and myocardial changes in women with a history of pre-eclampsia' (DECONNECT) pilot study includes women after pre-eclampsia and controls after normotensive pregnancy between 6 months and 20 years after gestation. We recruit women from the Queen of Hearts study, a study investigating subclinical heart failure after pre-eclampsia. Neuropsychological tests are employed to assess different cognitive domains, including attention, processing speed, and cognitive control. Cerebral images are recorded using a 7 Tesla MRI to assess blood-brain barrier integrity, perfusion, blood flow, functional and structural networks, and anatomical dimensions. Cardiac images are recorded using a 3 Tesla MRI to assess cardiac perfusion, strain, dimensions, mass, and degree of fibrosis. We assess the effect of a history of pre-eclampsia using multivariable regression analyses. ETHICS AND DISSEMINATION: This study is approved by the Ethics Committee of Maastricht University Medical Centre (METC azM/UM, NL47252.068.14). Knowledge dissemination will include scientific publications, presentations at conferences and public forums, and social media. TRIAL REGISTRATION NUMBER: NCT02347540.


Assuntos
Pré-Eclâmpsia , Feminino , Humanos , Gravidez , Cognição , Estudos Transversais , Miocárdio , Projetos Piloto
13.
J Neurosci ; 32(1): 4-11, 2012 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-22219265

RESUMO

The neural correlates for retention of visual information in visual short-term memory are considered separate from those of sensory encoding. However, recent findings suggest that sensory areas may play a role also in short-term memory. We investigated the functional relevance, spatial specificity, and temporal characteristics of human early visual cortex in the consolidation of capacity-limited topographic visual memory using transcranial magnetic stimulation (TMS). Topographically specific TMS pulses were delivered over lateralized occipital cortex at 100, 200, or 400 ms into the retention phase of a modified change detection task with low or high memory loads. For the high but not the low memory load, we found decreased memory performance for memory trials in the visual field contralateral, but not ipsilateral to the side of TMS, when pulses were delivered at 200 ms into the retention interval. A behavioral version of the TMS experiment, in which a distractor stimulus (memory mask) replaced the TMS pulses, further corroborated these findings. Our findings suggest that retinotopic visual cortex contributes to the short-term consolidation of topographic visual memory during early stages of the retention of visual information. Further, TMS-induced interference decreased the strength (amplitude) of the memory representation, which most strongly affected the high memory load trials.


Assuntos
Aprendizagem/fisiologia , Memória de Curto Prazo/fisiologia , Estimulação Magnética Transcraniana/métodos , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Córtex Visual/anatomia & histologia , Campos Visuais/fisiologia , Adulto Jovem
14.
J Neurosci ; 32(6): 1981-8, 2012 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-22323712

RESUMO

Practice-induced improvements in skilled performance reflect "offline " consolidation processes extending beyond daily training sessions. According to visual learning theories, an early, fast learning phase driven by high-level areas is followed by a late, asymptotic learning phase driven by low-level, retinotopic areas when higher resolution is required. Thus, low-level areas would not contribute to learning and offline consolidation until late learning. Recent studies have challenged this notion, demonstrating modified responses to trained stimuli in primary visual cortex (V1) and offline activity after very limited training. However, the behavioral relevance of modified V1 activity for offline consolidation of visual skill memory in V1 after early training sessions remains unclear. Here, we used neuronavigated transcranial magnetic stimulation (TMS) directed to a trained retinotopic V1 location to test for behaviorally relevant consolidation in human low-level visual cortex. Applying TMS to the trained V1 location within 45 min of the first or second training session strongly interfered with learning, as measured by impaired performance the next day. The interference was conditional on task context and occurred only when training in the location targeted by TMS was followed by training in a second location before TMS. In this condition, high-level areas may become coupled to the second location and uncoupled from the previously trained low-level representation, thereby rendering consolidation vulnerable to interference. Our data show that, during the earliest phases of skill learning in the lowest-level visual areas, a behaviorally relevant form of consolidation exists of which the robustness is controlled by high-level, contextual factors.


Assuntos
Aprendizagem por Discriminação/fisiologia , Destreza Motora/fisiologia , Estimulação Luminosa/métodos , Estimulação Magnética Transcraniana/métodos , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Aprendizagem/fisiologia , Masculino , Plasticidade Neuronal/fisiologia , Orientação/fisiologia , Tempo de Reação , Fatores de Tempo , Adulto Jovem
15.
Exp Brain Res ; 224(3): 477-88, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23161157

RESUMO

Tactile perceptual learning has been shown to improve performance on tactile tasks, but there is no agreement about the extent of transfer to untrained skin locations. The lack of such transfer is often seen as a behavioral index of the contribution of early somatosensory brain regions. Moreover, the time course of improvements has never been described explicitly. Sixteen subjects were trained on the Ludvigh task (a tactile vernier task) on four subsequent days. On the fifth day, transfer of learning to the non-trained contralateral hand was tested. In five subjects, we explored to what extent training effects were retained approximately 1.5 years after the final training session, expecting to find long-term retention of learning effects after training. Results showed that tactile perceptual learning mainly occurred offline, between sessions. Training effects did not transfer initially, but became fully available to the untrained contralateral hand after a few additional training runs. After 1.5 years, training effects were not fully washed out and could be recuperated within a single training session. Interpreted in the light of theories of visual perceptual learning, these results suggest that tactile perceptual learning is not fundamentally different from visual perceptual learning, but might proceed at a slower pace due to procedural and task differences, thus explaining the apparent divergence in the amount of transfer and long-term retention.


Assuntos
Aprendizagem/fisiologia , Percepção do Tato/fisiologia , Tato/fisiologia , Transferência de Experiência/fisiologia , Adulto , Feminino , Dedos/fisiologia , Humanos , Curva de Aprendizado , Masculino
16.
J Oral Facial Pain Headache ; 37(2): 139-148, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37389840

RESUMO

AIMS: To measure brain activity in patients with bruxism and temporomandibular disorder (TMD)-related pain in comparison to controls using functional magnetic resonance imaging (fMRI) and to investigate whether modulations in jaw clenching led to different pain reports and/or changes in neural activity in motor and pain processing areas within and between both groups. METHODS: A total of 40 participants (21 patients with bruxism and TMD-related pain and 19 healthy controls) performed a tooth-clenching task while lying inside a 3T MRI scanner. Participants were instructed to mildly or strongly clench their teeth for brief periods of 12 seconds and to subsequently rate their clenching intensity and pain experience after each clenching period. RESULTS: Patients reported significantly more pain during strong clenching compared to mild clenching. Further results showed significant differences between patients and controls in activity in areas of brain networks commonly associated with pain processing, which were also correlated with reported pain intensity. There was no evidence for differences in activity in motor-related areas between groups, which contrasts with findings of previous research. CONCLUSIONS: Brain activity in patients with bruxism and TMD-related pain is correlated more with pain processing than with motoric differences.


Assuntos
Bruxismo , Transtornos da Articulação Temporomandibular , Humanos , Dor , Encéfalo , Meios de Contraste , Transtornos da Articulação Temporomandibular/diagnóstico por imagem
17.
J Cogn Neurosci ; 24(2): 367-77, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21861682

RESUMO

Visual scene perception owes greatly to surface features such as color and brightness. Yet, early visual cortical areas predominantly encode surface boundaries rather than surface interiors. Whether human early visual cortex may nevertheless carry a small signal relevant for surface perception is a topic of debate. We induced brightness changes in a physically constant surface by temporally modulating the luminance of surrounding surfaces in seven human participants. We found that fMRI activity in the V2 representation of the constant surface was in antiphase to luminance changes of surrounding surfaces (i.e., activity was in-phase with perceived brightness changes). Moreover, the amplitude of the antiphase fMRI activity in V2 predicted the strength of illusory brightness perception. We interpret our findings as evidence for a surface-related signal in early visual cortex and discuss the neural mechanisms that may underlie that signal in concurrence with its possible interaction with the properties of the fMRI signal.


Assuntos
Sensibilidades de Contraste/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Estimulação Luminosa
18.
Neuroimage ; 59(2): 926-34, 2012 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-21964509

RESUMO

Changes in hemispheric asymmetry and inter-hemispheric connectivity have been reported in schizophrenia. However, the genetic contribution to these alterations is still unclear. In the current study, we applied an automatic segmentation method to structural MRI and diffusion tensor imaging (DTI) data and examined volume and fiber integrity of the corpus callosum (CC), the main interhemispheric fiber tract, in 16 chronic schizophrenia (SZ) patients, matched first degree relatives and controls. SZ patients and relatives had smaller CC volumes than controls, particularly in the posterior genu, isthmus and splenium. Fractional anisotropy (FA), an indicator of fiber integrity, was reduced in patients and relatives in the whole CC, the inferior genu, the superior genu and the isthmus. Correspondingly, the mean diffusivity (MD) values of the whole CC and the isthmus were higher in patients and their unaffected relatives, indicating decreased compactness and increased intercellular space. Relatives had intermediate values in the volumetric and fiber integrity measurements between patients and controls. Lower CC volume and fiber integrity in SZ patients were associated with more severe auditory hallucinations. These results support the connectivity hypothesis of SZ (Friston, 1998) and particularly highlight the altered interhemispheric connectivity, which appears to be a genetic feature of SZ risk.


Assuntos
Cérebro/patologia , Corpo Caloso/patologia , Imagem de Tensor de Difusão/métodos , Predisposição Genética para Doença/genética , Fibras Nervosas Mielinizadas/patologia , Esquizofrenia/genética , Esquizofrenia/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Vias Neurais/patologia , Tamanho do Órgão , Medição de Risco
19.
Cereb Cortex ; 21(2): 330-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20530219

RESUMO

Although auditory verbal hallucinations are often thought to denote mental illness, the majority of voice hearers do not satisfy the criteria for a psychiatric disorder. Here, we report the first functional imaging study of such nonclinical hallucinations in 7 healthy voice hearers comparing them with auditory imagery. The human voice area in the superior temporal sulcus was activated during both hallucinations and imagery. Other brain areas supporting both hallucinations and imagery included fronto temporal language areas in the left hemisphere and their contralateral homologues and the supplementary motor area (SMA). Hallucinations are critically distinguished from imagery by lack of voluntary control. We expected this difference to be reflected in the relative timing of prefrontal and sensory areas. Activity of the SMA indeed preceded that of auditory areas during imagery, whereas during hallucinations, the 2 processes occurred instantaneously. Voluntary control was thus represented in the relative timing of prefrontal and sensory activation, whereas the sense of reality of the sensory experience may be a product of the voice area activation. Our results reveal mechanisms of the generation of sensory experience in the absence of external stimulation and suggest new approaches to the investigation of the neurobiology of psychopathology.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Alucinações/patologia , Alucinações/fisiopatologia , Imaginação/fisiologia , Voz , Estimulação Acústica/métodos , Adulto , Córtex Cerebral/irrigação sanguínea , Sinais (Psicologia) , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Oxigênio/sangue , Tempo de Reação/fisiologia , Fatores de Tempo , Adulto Jovem
20.
Psychon Bull Rev ; 29(2): 568-580, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34647275

RESUMO

We tend to mentally segment a series of events according to perceptual contextual changes, such that items from a shared context are more strongly associated in memory than items from different contexts. It is also known that timing context provides a scaffold to structure experiences in memory, but its role in event segmentation has not been investigated. We adapted a previous paradigm, which was used to investigate event segmentation using visual contexts, to study the effects of changes in timing contexts on event segmentation in associative memory. In two experiments, we presented lists of 36 items in which the interstimulus intervals (ISIs) changed after a series of six items ranging between 0.5 and 4 s in 0.5 s steps. After each list, participants judged which one of two test items were shown first (temporal order judgment) for items that were either drawn from the same context (within an ISI) or from consecutive contexts (across ISIs). Further, participants judged from memory whether the ISI associated to an item lasted longer than a standard interval (2.25 s) that was not previously shown (temporal source memory). Experiment 2 further included a time-item encoding task. Results revealed an effect of timing context changes in temporal order judgments, with faster responses (Experiment 1) or higher accuracy (Experiment 2) when items were drawn from the same context, as opposed to items drawn from across contexts. Further, in both experiments, we found that participants were well able to provide temporal source memory judgments based on recalled durations. Finally, replicated across experiments, we found subjective duration bias, as estimated by psychometric curve fitting parameters of the recalled durations, correlated negatively with within-context temporal order judgments. These findings show that changes in timing context support event segmentation in associative memory.


Assuntos
Julgamento , Rememoração Mental , Humanos
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