Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add more filters










Database
Language
Publication year range
1.
Article in English | MEDLINE | ID: mdl-33857639

ABSTRACT

BACKGROUND: Affective dysregulation (AD), or synonymously "irritability," is a transdiagnostic construct that serves as a diagnostic criterion in various childhood mental disorders. It is characterized by severe or persistent outbursts of anger and aggression. Emotional self-regulation is highly dependent on the ability to process relevant and ignore conflicting emotional information. Understanding neurophysiological mechanisms underlying impairment in AD may provide a starting point for research on pharmacological treatment options and evaluation of psychotherapeutic intervention. METHODS: A total of 120 children 8 to 12 years of age (63 with AD and 57 typically developing) were examined using an emotional Stroop task. Signal-decomposed electroencephalographic recordings providing information about the affected sensory-perceptual, response selection, or motor information processing stage were combined with source localization. RESULTS: Behavioral performance revealed dysfunctional cognitive-emotional conflict monitoring in children with AD, suggesting difficulties in differentiating between conflicting and nonconflicting cognitive-emotional information. This was confirmed by the electroencephalographic data showing that they cannot intensify response selection processes during conflicting cognitive-emotional situations. Typically developing children were able to do so and activated a functional-neuroanatomical network comprising the left inferior parietal cortex (Brodmann area 40), right middle frontal (Brodmann area 10), and right inferior/orbitofrontal (Brodmann area 47) regions. Purely sensory-perceptual selection and motor execution processes were not modulated in AD, as evidenced by Bayesian analyses. CONCLUSIONS: Behavioral and electroencephalogram data suggest that children with AD cannot adequately modulate controlled response selection processes given emotionally ambiguous information. Which neurotransmitter systems underlie these deficits and how they can be improved are important questions for future research.


Subject(s)
Cognition , Emotions , Bayes Theorem , Child , Cognition/physiology , Electroencephalography , Emotions/physiology , Humans , Stroop Test
2.
Cortex ; 132: 15-28, 2020 11.
Article in English | MEDLINE | ID: mdl-32911231

ABSTRACT

Consciously and subliminally processed information can both lead to conflicts that hinder goal-directed behaviour. Conflict monitoring processes are required to cope with situations where one or multiple conflicts occur. It has been suggested, that medial-frontal theta oscillations are associated with the implementation of cognitive control and that conflicts increase theta band activity. Still, a causal mechanistic understanding of theta oscillations during the resolution of combined subliminal and conscious conflicts is missing. To investigate this, we combined EEG signal decomposition methods with EEG beamforming approaches and used the obtained information to modulate theta oscillations with tACS in a second experiment. This showed that theta oscillations in the superior frontal cortex (BA6) and the left paracentral lobule encoded stimulus-related processes during the resolution of conflicts arising from both conscious and subliminal information processing. Response selection and motor-related processes encoded by theta oscillations were not similarly modulated. Thus, the joint modulation of conflicts by conscious and subliminal information affects very specific aspects of the information coded in theta oscillations. Results indicate, that entraining theta-oscillations using tACS modulates conflict resolution depending on the already existing theta activity level. In summary, the study provides further evidence that frontal theta oscillations play a crucial role in conflict monitoring and control.


Subject(s)
Frontal Lobe , Theta Rhythm , Cognition , Consciousness , Electroencephalography , Humans
3.
Cortex ; 128: 22-34, 2020 07.
Article in English | MEDLINE | ID: mdl-32311545

ABSTRACT

Sequential cognitive flexibility is a major requirement for goal-directed behavior. Recent findings show that inhibitory control processes are crucial for sequential cognitive flexibility. These processes are indicated by the 'backward inhibition (BI) effect' which emerges when a mental representation that has recently been suppressed in favour of another task has to be re-activated. Alterations in the catecholaminergic neural transmission including the norepinephrine (NE) system have been shown to modulate inhibitory processes. However, a possible role of the NE system in sequential cognitive flexibility is elusive. The present study examines the relevance of the NE system for sequential cognitive flexibility by integrating pupil diameter data and electrophysiological (EEG) data applying signal decomposition techniques and source localization. We show that the BI effects modulated amplitudes in the P1/N1 time window, as well as in the N2 time window. Correlating this data with the pupil diameter data only revealed substantial correlations in the P1/N1 time window. Moreover, it is shown that regions in the right inferior frontal gyrus are activated during modulations in the P1 time window, in which correlations with the pupil diameter data were also evident. The results are interpreted that sequential cognitive flexibility modulates early inhibitory gating processes (P1) which are related to the suppression of task-irrelevant information in inferior frontal regions. These processes are likely modulated by the NE system.


Subject(s)
Norepinephrine , Pupil , Cognition , Electroencephalography , Humans , Inhibition, Psychological
5.
Brain Struct Funct ; 224(7): 2343-2355, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31218393

ABSTRACT

Albeit cognitive flexibility is well known to decline in aging, it has not been considered that this ability often requires sequential task control. That is, one may re-use tasks that have previously been abandoned in favor of another task. It is unclear whether sequential cognitive flexibility is affected in aging and what neurophysiological mechanisms and functional neuroanatomical structures are associated with these effects. We examined this question in a system neurophysiological study using EEG and source localization in healthy and elderly adults. We show that elderly people reveal deficient sequential cognitive flexibility. Elderly people encounter increased costs to overcome the inhibition of the lately abandoned task set that becomes relevant again and needs to be re-used. The neurophysiological (EEG) data show that differences in sequential cognitive flexibility between young and elderly people emerge as a consequence of two independent, dysfunctional processes: (i) the ability to suppress task-irrelevant information and (ii) the ability to re-implement a previously abandoned task set during response selection. These independent processes were associated with activation differences in inferior frontal and inferior parietal regions. The study reveals a new facet of cognitive flexibility dysfunctions in healthy elderlies.


Subject(s)
Aging/physiology , Attention/physiology , Brain/physiology , Cognition/physiology , Adult , Aged , Electroencephalography/methods , Female , Humans , Inhibition, Psychological , Male , Middle Aged , Neural Pathways/physiology , Neuropsychological Tests , Reaction Time/physiology , Young Adult
6.
Hum Brain Mapp ; 40(2): 552-565, 2019 02 01.
Article in English | MEDLINE | ID: mdl-30240511

ABSTRACT

Cognitive flexibility is a major facet of executive functions and often refers to sequential task control; that is, it is very likely that one may re-encounter a task that has previously been abandoned to carry out a different task. In the context of sequential cognitive flexibility, the "backward inhibition (BI) effect" has been studied quite extensively. Here we ask whether there are age-related differences between adolescents and adults to overcome BI and what system-neurophysiological mechanisms underlie these modulations. This was examined using a system neurophysiological study procedure combining event-related potentials data with source localization and EEG signal decomposition methods. We show that sequential cognitive flexibility, and the ability overcome backward inhibition, is inferior in adolescents compared with adults. Accounting for intra-individual variability in the neurophysiological data, this data suggest that two partly inter-related processes underlie the differences between adolescents than adults to overcome backward inhibition: One process refers to the suppression of the inhibitory effect of the n-1 trial on the n-2 trial during perceptual categorization of incoming information that is associated with right inferior frontal regions. The other process refers to immature response selection and conflict monitoring mechanisms associated with regions in the medial frontal cortex.


Subject(s)
Adolescent Development/physiology , Electroencephalography/methods , Evoked Potentials/physiology , Executive Function/physiology , Inhibition, Psychological , Prefrontal Cortex/physiology , Psychomotor Performance/physiology , Adolescent , Adult , Conflict, Psychological , Female , Humans , Male , Prefrontal Cortex/growth & development , Young Adult
7.
J Child Psychol Psychiatry ; 59(9): 1024-1032, 2018 09.
Article in English | MEDLINE | ID: mdl-29603217

ABSTRACT

BACKGROUND: A major facet of obsessive-compulsive disorder (OCD) is cognitive inflexibility. However, sometimes, cognitive flexibility can be needed to reuse recently abandoned mental sets. Therefore, cognitive flexibility can in certain cases be useful to reinstate some form of rigid, repetitive behavior characterizing OCD. We test the counterintuitive hypothesis that under such circumstances, cognitive flexibility is better in OCD patients than controls. METHODS: We examined N = 20 adolescent OCD patients and N = 22 controls in a backward inhibition (BI) paradigm. This was combined with event-related potential (ERP) recordings and source localization. The BI effect describes the cost of overcoming the inhibition of a recently abandoned mental set that is relevant again. Therefore, a strong BI effect is disadvantageous for cognitive flexibility. RESULTS: Compared to controls, OCD patients revealed a smaller backward inhibition effect. The EEG data revealed larger P1 amplitudes in backward inhibition trials in the OCD group, which was due to activation differences in the inferior frontal gyrus (BA47). The severity of clinical symptoms predicted these neurophysiological modulations. The power of the observed effects was about 95%. CONCLUSIONS: The study shows that cognitive flexibility can be better in OCD than controls. This may be the case in situations where superior abilities in the reactivation of repeating mental sets and difficulties to process new ones coincide. This may be accomplished by intensified inhibitory control mechanisms. The results challenge the view on OCD, since OCD is not generally associated with cognitive inflexibility.


Subject(s)
Evoked Potentials/physiology , Executive Function/physiology , Inhibition, Psychological , Obsessive-Compulsive Disorder/physiopathology , Psychomotor Performance/physiology , Adolescent , Electroencephalography , Humans
SELECTION OF CITATIONS
SEARCH DETAIL
...