194 research outputs found
Feedback information transfer in the human brain reflects bistable perception in the absence of report
In the search for the neural basis of conscious experience, perception and the cognitive processes associated with reporting perception are typically confounded as neural activity is recorded while participants explicitly report what they experience. Here, we present a novel way to disentangle perception from report using eye movement analysis techniques based on convolutional neural networks and neurodynamical analyses based on information theory. We use a bistable visual stimulus that instantiates two well-known properties of conscious perception: integration and differentiation. At any given moment, observers either perceive the stimulus as one integrated unitary object or as two differentiated objects that are clearly distinct from each other. Using electroencephalography, we show that measures of integration and differentiation based on information theory closely follow participants' perceptual experience of those contents when switches were reported. We observed increased information integration between anterior to posterior electrodes (front to back) prior to a switch to the integrated percept, and higher information differentiation of anterior signals leading up to reporting the differentiated percept. Crucially, information integration was closely linked to perception and even observed in a no-report condition when perceptual transitions were inferred from eye movements alone. In contrast, the link between neural differentiation and perception was observed solely in the active report condition. Our results, therefore, suggest that perception and the processes associated with report require distinct amounts of anterior-posterior network communication and anterior information differentiation. While front-to-back directed information is associated with changes in the content of perception when viewing bistable visual stimuli, regardless of report, frontal information differentiation was absent in the no-report condition and therefore is not directly linked to perception per se.</p
OC-0160: Growth and oedema related shifts of brain metastasis treated with stereotactic radiosurgery
An academic survey on theoretical foundations, common assumptions and the current state of consciousness science
Preserved sensory processing but hampered conflict detection when stimulus input is task-irrelevant
Preserved sensory processing but hampered conflict detection when stimulus input is task-irrelevant
Decreased Alertness Reconfigures Cognitive Control Networks
Humans' remarkable capacity to flexibly adapt their behavior based on rapid situational changes is termed cognitive control. Intuitively, cognitive control is thought to be affected by the state of alertness; for example, when drowsy, we feel less capable of adequately implementing effortful cognitive tasks. Although scientific investigations have focused on the effects of sleep deprivation and circadian time, little is known about how natural daily fluctuations in alertness in the regular awake state affect cognitive control. Here we combined a conflict task in the auditory domain with EEG neurodynamics to test how neural and behavioral markers of conflict processing are affected by fluctuations in alertness. Using a novel computational method, we segregated alert and drowsy trials from two testing sessions and observed that, although participants (both sexes) were generally sluggish, the typical conflict effect reflected in slower responses to conflicting information compared with nonconflicting information, as well as the moderating effect of previous conflict (conflict adaptation), were still intact. However, the typical neural markers of cognitive control—local midfrontal theta-band power changes—that participants show during full alertness were no longer noticeable when alertness decreased. Instead, when drowsy, we found an increase in long-range information sharing (connectivity) between brain regions in the same frequency band. These results show the resilience of the human cognitive control system when affected by internal fluctuations of alertness and suggest that there are neural compensatory mechanisms at play in response to physiological pressure during diminished alertness
Do Surgical Interventions Influence Psychosexual and Cosmetic Outcomes in Women with Disorders of Sex Development?
Clinical practice developed to promote psychosexual well-being in DSD is under scrutiny. Although techniques for genital surgery have much improved lately, long-term studies on psychosexual functioning and cosmetic outcome on which to base treatment and counseling are scarce. We studied 91 women with a DSD. Feminizing surgery was performed in 64% of the women; in 60% of them, resurgery in puberty was needed after a single-stage procedure. Both patients and gynecologists were satisfied with the cosmetic appearance of the genitalia. However, forty percent of these females experienced sexuality-related distress and 66% was at risk for developing a sexual dysfunction, whether they had surgery or not. Recognizing the difficulty of accurate assessment, our data indicate that feminizing surgery does not seem to improve nor hamper psychosexual outcome, especially in patients with severe virilization
Female reproductive function after treatment of childhood acute lymphoblastic leukemia
Background The aim was to evaluate self-reported reproductive characteristics and markers of ovarian function in a nationwide cohort of female survivors of childhood acute lymphoblastic leukemia (ALL), because prior investigations have produced conflicting data. Procedure Self-reported reproductive characteristics were assessed by questionnaire among 357 adult 5-year survivors, treated between 1964 and 2002, and 836 controls. Ovarian function was assessed by serum levels of anti-Mullerian hormone (AMH), follicle-stimulating hormone (FSH), and inhibin B and by antral follicle count (AFC). Differences between controls and (subgroups of) survivors (total group, chemotherapy [CT]-only group, CT and radiotherapy [RT] group) were analyzed. Results Survivors treated with CT only do not differ from controls regarding timing of menarche, virginity status, desire for children, or pregnancy rates. Compared to controls, the CT+RT group was at significantly increased risk of a younger age at menarche (P < .01), virginity, an absent desire for children, and lower pregnancy rates (odds ratio [OR] [95% CI]: 0.3 [CI 0.1-0.6], 0.5 [0.3-0.9], and 0.4 [0.2-0.9], respectively). Survivors in the CT-only group were significantly younger at the birth of their first child. Pregnancy outcomes were not significantly different between any (sub)groups. Survivors treated with total body irradiation (TBI) or hematopoietic stem cell transplantation (HSCT) are at increased risk of abnormal markers of ovarian function. Conclusion Reproductive function of ALL survivors treated with CT only does not differ from controls. However, survivors additionally treated with RT seem to be at an increased risk of certain adverse reproductive outcomes. Providing personalized counseling about (future) reproductive health risks in this group is imperative
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