1,722,169 research outputs found
De nalatenschap van Piet Vroon: Prutswerk? Review of Weg met Piet Vroon: Een biografie. V. Busato
No full text
Center-surround inhibition and facilitation as a function of size and contrast at multiple levels of visual motion processing
No full textA framework for targeting alternative brain regions with repetitive transcranial magnetic stimulation in the treatment of depression
Full text linkContains fulltext :
119672.pdf (Publisher’s version ) (Open Access)It has been argued that clinical depression is accompanied by reductions in cortical excitability of the left prefrontal cortex (PFC). In support of this, repetitive transcranial magnetic stimulation (rTMS), which is a method of enhancing cortical excitability, has shown antidepressant efficacy when applied over the left PFC, although the overall therapeutic effects remain inconclusive. The cerebral pathophysiology of depression is, however, not limited to dysfunctions in the PFC, thus, targeting alternative brain regions with rTMS may provide new therapeutic windows in the treatment of depression. Evidence from electroencephalography and lesion studies suggests that not only is the left PFC involved in depression but also the parietal cortex and cerebellum. Furthermore, rTMS over the parietal cortex and the cerebellum has been found to improve mood and emotional functioning, at least in healthy volunteers. We have integrated these findings in an rTMS-oriented theoretical framework for the neurobiology of low mood and depression. To establish the possible therapeutic efficacy of this model, whereby, for example, the application of slow rTMS over the right parietal cortex and fast rTMS over the cerebellum may be beneficial in different subtypes of depression, clinical rTMS studies that target the parietal cortex and cerebellum are warranted.7 p
Extending the global workspace theory to emotion: Phenomenality without access
No full textItem does not contain fulltextRecent accounts on the global workspace theory suggest that consciousness involves transient formations of functional connections in thalamo-cortico-cortical networks. The level of connectivity in these networks is argued to determine the state of consciousness. Emotions are suggested to play a role in shaping consciousness, but their involvement in the global workspace theory remains elusive. In the present study, the role of emotion in the neural workspace theory of consciousness was scrutinized by investigating, whether unconscious (masked) and conscious (unmasked) display of emotional compared to neutral facial expressions would differentially modulate EEG coherence. EEG coherence was measured by means of computing an average EEG coherence value between the frontal, parietal, and midline scalp sites. Objective awareness checks evidenced that conscious identification of the masked facial expressions was precluded. Analyses revealed reductions in EEG coherence in the lower frequency range for the masked as compared to unmasked neutral facial expressions. Crucially, a decline in EEG coherence was not observed for the emotional facial expressions. In other words, the level of EEG coherence did apparently vary as a function of awareness, but not when emotion was involved. The current finding suggests that EEG coherence is modulated by unconscious emotional processes, which extends common views on the global workspace architecture of consciousness
Administration of testosterone increases functional connectivity in a cortico-cortical depression circuit
No full textItem does not contain fulltextIncreasing evidence suggests that the steroid hormone testosterone (T) enhances libido and decreases depression. Even a single administration of T (0.5 mg sublingually) in healthy young women is sufficient to enhance physiological sexual responsiveness. Such physiological evidence is not yet available for the link between T and depression. Recent research has revealed that lowered functional connectivity in a specific cortico-cortical pathway may be a sensitive physiological index for depression. This pathway, comprised of the left prefrontal and right parietal cortex, has been named a cortical depression circuit. In the present study, a single dose of T was administered to healthy young women to investigate the effects on the functional connectivity in this cortico-cortical depression circuit. It was hypothesized that administration of T would lead to an increase of functional connectivity. In a double-blind placebo-controlled, crossover design, fourteen healthy females received (sublingually) a single dose of 0.5 mg T or placebo in a randomly assigned fashion. Three hours after drug administration the functional coupling between the left prefrontal and right parietal cortex was established by measuring the interhemispheric electroencephalogram (EEG) coherence for the different frequency bands. Compared to placebo, T administration significantly increased the functional connectivity in the σ (1—3 Hz) frequency range between the left prefrontal and right parietal cortex. Reductions in interhemispheric coherence in the σ frequency range have been observed in clinically depressed patients. Thus the present findings may provide a first insight into the neurobiological mechanism by which T decreases depression. The fact that only a single dose of T was able to induce the effect in healthy female subjects suggests that the mechanism is highly sensitive. A feasible application of T treatment in the struggle against depression is discussed
- …
