Ribeiro, Maria
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Credit Name
Ribeiro, Maria
Variants
Ribeiro, Maria J.
Ribeiro, M. J.
Ribeiro, M. J.
Unidade de I&D
Scopus Author ID
Researcher ID
Status
UC Researcher
Biography
Biography
One of the great mysteries is how the human brain creates and controls our thoughts, emotions and behaviour.
My research contributes towards unveiling the neural mechanisms behind perception, decision and action in humans using non-invasive neuroimaging techniques and physiological recordings.
Underneath is a summary of some of the projects in which I have been involved.
ASCENDING BRAINSTEM AROUSAL SYSTEMS AND AGE-RELATED COGNITIVE DECLINE
I am interested in understanding the neural changes that occur in ageing, are causal to cognitive decline and contribute for the onset of neurodegenerative diseases associated with the ageing process. In particular, I am studying the impact of changes in the ascending arousal systems of the brainstem. Neuromodulators with brainstem origin, like noradrenaline, dopamine and serotonin, can have a protective effect in the brain, keeping cognitive decline at bay. Yet, how these systems change with ageing and if we are able to modulate them to our benefit remains to be determined.
In previous studies, we have analysed the pupilogram and electrocardiogram (ECG) as indirect measures of activity in the arousal systems (Ribeiro and Castelo-Branco 2019a; Ribeiro and Castelo-Branco, 2019 b). These studies suggested reduced arousal modulation during perceptual decision-making in older people. In particular, task-related modulation of heart rate was reduced in older participants and correlated with reduced processing speed, suggesting that activity in these systems is directly associated with the cognitive abilities of older individuals.
ATTENTIONAL FLUCTUATIONS AND THE TIME OF NEURAL RESPONSES
In this study, we took advantage of the high temporal resolution of the electroencephalogram (EEG) to demonstrate that moment-to-moment fluctuations in the timing (and not amplitude) of neural responses in the visual cortex correlate with fluctuations in behavioural responses. Neuronal timing emerges as an important indicator of brain state fluctuations (Ribeiro et al., 2016).
BRAIN STRUCTURAL, FUNCTIONAL AND MOLECULAR CHANGES IN A NEURODEVELOPMENTAL DISORDER
We combined structural and functional magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS) and electroencephalography (EEG) to elucidate the neural mechanisms behind the cognitive deficits observed in individuals with the monogenic disorder, neurofibromatosis type 1 (NF1).
Individuals with NF1 presented impaired cognitive control associated with deficient frontal activation and abnormal GABAergic transmission (Ribeiro et al., 2015; Violante et al., 2013). Brain structural differences were particularly pronounced in the white-matter. Using multivariate pattern analysis we were able to successfully classify patients from controls using brain imaging parameters (Duarte et al., 2014).
One of the great mysteries is how the human brain creates and controls our thoughts, emotions and behaviour.
My research contributes towards unveiling the neural mechanisms behind perception, decision and action in humans using non-invasive neuroimaging techniques and physiological recordings.
Underneath is a summary of some of the projects in which I have been involved.
ASCENDING BRAINSTEM AROUSAL SYSTEMS AND AGE-RELATED COGNITIVE DECLINE
I am interested in understanding the neural changes that occur in ageing, are causal to cognitive decline and contribute for the onset of neurodegenerative diseases associated with the ageing process. In particular, I am studying the impact of changes in the ascending arousal systems of the brainstem. Neuromodulators with brainstem origin, like noradrenaline, dopamine and serotonin, can have a protective effect in the brain, keeping cognitive decline at bay. Yet, how these systems change with ageing and if we are able to modulate them to our benefit remains to be determined.
In previous studies, we have analysed the pupilogram and electrocardiogram (ECG) as indirect measures of activity in the arousal systems (Ribeiro and Castelo-Branco 2019a; Ribeiro and Castelo-Branco, 2019 b). These studies suggested reduced arousal modulation during perceptual decision-making in older people. In particular, task-related modulation of heart rate was reduced in older participants and correlated with reduced processing speed, suggesting that activity in these systems is directly associated with the cognitive abilities of older individuals.
ATTENTIONAL FLUCTUATIONS AND THE TIME OF NEURAL RESPONSES
In this study, we took advantage of the high temporal resolution of the electroencephalogram (EEG) to demonstrate that moment-to-moment fluctuations in the timing (and not amplitude) of neural responses in the visual cortex correlate with fluctuations in behavioural responses. Neuronal timing emerges as an important indicator of brain state fluctuations (Ribeiro et al., 2016).
BRAIN STRUCTURAL, FUNCTIONAL AND MOLECULAR CHANGES IN A NEURODEVELOPMENTAL DISORDER
We combined structural and functional magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS) and electroencephalography (EEG) to elucidate the neural mechanisms behind the cognitive deficits observed in individuals with the monogenic disorder, neurofibromatosis type 1 (NF1).
Individuals with NF1 presented impaired cognitive control associated with deficient frontal activation and abnormal GABAergic transmission (Ribeiro et al., 2015; Violante et al., 2013). Brain structural differences were particularly pronounced in the white-matter. Using multivariate pattern analysis we were able to successfully classify patients from controls using brain imaging parameters (Duarte et al., 2014).
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Results 1-3 of 3 (Search time: 0.003 seconds).
| Issue Date | Title | Author(s) | Type | Access | |
|---|---|---|---|---|---|
| 1 | 25-Jan-2012 | Abnormal achromatic and chromatic contrast sensitivity in neurofibromatosis type 1 | Ribeiro, Maria José ; Violante, Inês R ; Bernardino, Inês ; Ramos, Fabiana ; Saraiva, Jorge ; Reviriego, Pablo ; Upadhyaya, Meena ; Silva, Eduardo D. ; Castelo-Branco, Miguel | article | openAccess |
| 2 | 2012 | Abnormal brain activation in neurofibromatosis type 1: a link between visual processing and the default mode network | Violante, Inês R. ; Ribeiro, Maria J. ; Cunha, Gil ; Bernardino, Inês ; Duarte, João V. ; Ramos, Fabiana ; Saraiva, Jorge ; Silva, Eduardo ; Castelo-Branco, Miguel | article | openAccess |
| 3 | Mar-2015 | Abnormal relationship between GABA, neurophysiology and impulsive behavior in neurofibromatosis type 1 | Ribeiro, Maria J. ; Violante, Inês R ; Bernardino, Inês ; Edden, Richard A E ; Castelo-Branco, Miguel | article | closedAccess |