Search results for "Neurosciences. Biological psychiatry. Neuropsychiatry"
showing 10 items of 652 documents
EEG and MEG primers for tracking DBS network effects
2020
Deep brain stimulation (DBS) is an effective treatment method for a range of neurological and psychiatric disorders. It involves implantation of stimulating electrodes in a precisely guided fashion into subcortical structures and, at a later stage, chronic stimulation of these structures with an implantable pulse generator. While the DBS surgery makes it possible to both record brain activity and stimulate parts of the brain that are difficult to reach with non-invasive techniques, electroencephalography (EEG) and magnetoencephalography (MEG) provide complementary information from other brain areas, which can be used to characterize brain networks targeted through DBS. This requires, howeve…
Aproximación psicopatológica a El Quijote (según la nosología psiquiátrica actual)
2003
Se analiza la psicopatología de Don Quijote y se revisan los estudios previos sobre el personaje, tanto desde la perspectiva médica como la literaria. Considerando el enfoque de la nosología psiquiátrica actual, Don Quijote cumpliría criterios para un Trastorno Delirante y esto se argumenta en base a la génesis del delirio, la sintomatología y los rasgos formales del delirio. Asimismo, se propone el diagnóstico de Trastorno Psicótico Compartido para la pareja protagonista (Don Quijote y Sancho).
Chronic fluoxetine treatment in middle-aged rats induces changes in the expression of plasticity-related molecules and in neurogenesis
2012
Abstract Background Antidepressants promote neuronal structural plasticity in young-adult rodents, but little is known of their effects on older animals. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) may mediate these structural changes through its anti-adhesive properties. PSA-NCAM is expressed in immature neurons and in a subpopulation of mature interneurons and its expression is modulated by antidepressants in the telencephalon of young-adult rodents. Results We have analyzed the effects of 14 days of fluoxetine treatment on the density of puncta expressing PSA-NCAM and different presynaptic markers in the medial prefrontal cortex, hippocampus and amygdala of mi…
Up and Down States During Slow Oscillations in Slow-Wave Sleep and Different Levels of Anesthesia
2021
Slow oscillations are a pattern of synchronized network activity generated by the cerebral cortex. They consist of Up and Down states, which are periods of activity interspersed with periods of silence, respectively. However, even when this is a unique dynamic regime of transitions between Up and Down states, this pattern is not constant: there is a range of oscillatory frequencies (0.1–4 Hz), and the duration of Up vs. Down states during the cycles is variable. This opens many questions. Is there a constant relationship between the duration of Up and Down states? How much do they vary across conditions and oscillatory frequencies? Are there different sub regimes within the slow oscillation…
How Many Clocks, How Many Times? On the Sensory Basis and Computational Challenges of Circadian Systems
2018
A vital task for every organism is not only to decide what to do but also when to do it. For this reason, “circadian clocks” have evolved in virtually all forms of life. Conceptually, circadian clocks can be divided into two functional domains; an autonomous oscillator creates a ~24 h self-sustained rhythm and sensory machinery interprets external information to alter the phase of the autonomous oscillation. It is through this simple design that variations in external stimuli (for example, daylight) can alter our sense of time. However, the clock’s simplicity ends with its basic concept. In metazoan animals, multiple external and internal stimuli, from light to temperature and even metaboli…
Children at risk for dyslexia show deficient left-hemispheric memory representations for new spoken word forms
2021
Developmental dyslexia is a specific learning disorder with impairments in reading and spelling acquisition. Apart from literacy problems, dyslexics show inefficient speech encoding and deficient novel word learning, with underlying problems in phonological processing and learning. These problems have been suggested to be related to deficient specialization of the left hemisphere for language processing. To examine this possibility, we tracked with magnetoencephalography (MEG) the activation of the bilateral temporal cortices during formation of neural memory traces for new spoken word forms in 7–8-year-old children with high familial dyslexia risk and in controls. The at-risk children impr…
Event-Related Potentials (ERP) Indices of Motivation during the Effort Expenditure for Reward Task
2020
Dynamic and temporal facets of the various constructs that comprise motivation remain to be explored. Here, we adapted the Effort Expenditure for Reward Task, a well-known laboratory task used to evaluate motivation, to study the event-related potentials associated with reward processing. The Stimulus Preceding Negativity (SPN) and the P300 were utilized as motivation indicators with high density electroencephalography. The SPN was found to be more negative for difficult choices compared to easy choices, suggesting a greater level of motivation, at a neurophysiological level. The insula, a structure previously associated with both effort discounting and prediction error, was concomitantly a…
Behavioral and Neural Arguments of Motivational Influence on Decision Making During Uncertainty
2020
The scientific world is increasingly interested in motivation, primarily due to the suspected impact on decision-making abilities, particularly in uncertain conditions. To explore this plausible relationship, 28 healthy participants were included in the study and performed decision-making and motivational tasks while their neural activity was recorded. All participants performed the Iowa Gambling Task (IGT) and were split into two groups based on their score, one favorable group with 14 participants who performed advantageously and one undecided group with 14 participants who failed to develop the correct strategy on the IGT. In addition, all participants performed the Effort Expenditure fo…
Electrophysiological evidence for change detection in speech sound patterns by anesthetized rats
2014
Human infants are able to detect changes in grammatical rules in a speech sound stream. Here, we tested whether rats have a comparable ability by using an electrophysiological measure that has been shown to reflect higher order auditory cognition even before it becomes manifested in behavioral level. Urethane-anesthetized rats were presented with a stream of sequences consisting of three pseudowords carried out at a fast pace. Frequently presented “standard” sequences had 16 variants which all had the same structure. They were occasionally replaced by acoustically novel “deviant” sequences of two different types: structurally consistent and inconsistent sequences. Two stimulus conditions we…
Empirical evidence for musical syntax processing? Computer simulations reveal the contribution of auditory short-term memory
2014
During the last decade, it has been argued that (1) music processing involves syntactic representations similar to those observed in language, and (2) that music and language share similar syntactic-like processes and neural resources. This claim is important for understanding the origin of music and language abilities and, furthermore, it has clinical implications. The Western musical system, however, is rooted in psychoacoustic properties of sound, and this is not the case for linguistic syntax. Accordingly, musical syntax processing could be parsimoniously understood as an emergent property of auditory memory rather than a property of abstract processing similar to linguistic processing.…