Facultad de Psicologia

Este artículo presenta resultados de una investigación en torno a la experiencia de la niñez en la última dictadura cívico-militar en Chile (1973-1990). Se discute el lugar que han ocupado los recuerdos de infancia en los estudios de memoria respecto a este periodo. Se acude a la perspectiva de los nuevos estudios de infancia para dirigir la mirada sobre aspectos poco visibles de la vida cotidiana. Se realizaron 24 entrevistas abiertas a personas que vivieron la niñez en dictadura. La entrevista fue concertada a propósito de un objeto (carta, diario de vida, tarjetas postales, grabaciones, etc.) producido o adquirido por el participante entre 1973-1990. En las conclusiones se reflexiona respecto al papel de la reconstrucción de los recuerdos de infancia mediante el uso de objetos ayuda-memoria y los aspectos universales de la experiencia de niñez en dictadura.

En este artículo de investigación recuperamos la voz de los hijos-niños e hijas-niñas de la gente militante de la izquierda de Chile, a partir del análisis de sus producciones simbólicas y registros de la vida cotidiana tales como cartas, dibujos, objetos realizados entre 1973 y 1989, y entrevistas registradas en documentales de la época que se encuentran actualmente en el Museo de la Memoria y los Derechos Humanos de Santiago de Chile, analizadas desde la perspectiva de los nuevos estudios de la infancia. Reflexionamos respecto al modo en que los niños y niñas elaboran su juicio y sentido de la realidad y construyen un sentido ético que dialoga con la herencia intergeneracional, pero la excede, reflejando su activa participación en la construcción de una comunidad afectiva que trasciende los vínculos consanguíneos.

El presente trabajo de investigación tiene como objetivo exponer los problemas conceptuales y terminológicos observados en la regulación del término “trastorno mental” en el Código Penal chileno, en especial, aquellos derivados del artículo 10.1, referido a las conductas exentas de responsabilidad penal. La problemática radica tanto a nivel dogmático, como en su relación con la realidad social que se pretende regular.
Con este objeto, los autores realizan un examen dogmático-jurídico y desde las disciplinas abocadas a la salud mental del concepto de “trastorno mental”, revisando los pronunciamientos de los documentos
institucionales internacionales más importantes, señalando el estado
de la cuestión y alcanzando la respuesta científica a esta cuestión jurídica. Finalmente, y a modo de conclusión, brindan una propuesta de lege ferenda orientada a la redacción del tenor de una disposición
normativa que regule las conductas que eximen de responsabilidad penal por trastorno mental.

Oscillatory phenomena have been a focus of dynamical systems research since the time of the classical studies on the pendulum by Galileo. Fast cortical oscillations also have a long and storied history in neurophysiology, and olfactory oscillations have led the way with a depth of explanation not present in the literature of most other cortical systems. From the earliest studies of odor-evoked oscillations by Adrian, many reports have focused on mechanisms and functional associations of these oscillations, in particular for the so-called gamma oscillations. As a result, much information is now available regarding the biophysical mechanisms that underlie the oscillations in the mammalian olfactory system. Recent studies have expanded on these and addressed functionality directly in mammals and in the analogous insect system. Sub-bands within the rodent gamma oscillatory band associated with specific behavioral and cognitive states have also been identified. All this makes oscillatory neuronal networks a unique interdisciplinary platform from which to study neurocognitive and dynamical phenomena in intact, freely behaving animals. We present here a summary of what has been learned about the functional role and mechanisms of gamma oscillations in the olfactory system as a guide for similar studies in other cortical systems.

Olfactory system oscillations play out with beautiful temporal and behavioral regularity on the oscilloscope and seem to scream 'meaning'. Always there is the fear that, although attractive, these symbols of dynamic regularity might be just seductive epiphenomena. There are now many studies that have isolated some of the neural mechanisms involved in these oscillations, and recent work argues that they are functional and even necessary at the physiological and cognitive levels. However, much remains to be done for a full understanding of their functions.

Background/Aims-Endothelial nitric oxide synthase (eNOS) is associated with caveolin-1 (Cav-1) in plasma membrane. We tested the hypothesis that eNOS activation by shear stress in resistance vessels depends on synchronized phosphorylation, dissociation from Cav-1 and translocation of the membrane-bound enzyme to Golgi and cytosol.

Sensory-motor relationships are part of the normal operation of sensory systems. Sensing occurs in the context of active sensor movement, which in turn influences sensory processing. We address such a process in the rat olfactory system. Through recordings of the diaphragm electromyogram (EMG), we monitored the motor output of the respiratory circuit involved in sniffing behavior, simultaneously with the local field potential (LFP) of the olfactory bulb (OB) in rats moving freely in a familiar environment, where they display a wide range of respiratory frequencies. We show that the OB LFP represents the sniff cycle with high reliability at every sniff frequency and can therefore be used to study the neural representation of motor drive in a sensory cortex.

Although there is extensive literature about the effects of stimulants on sustained attention tasks in attentional deficit/hyperactivity disorder (ADHD), little is known about the effect of these drugs on other attentional tasks involving different neural systems. In this study we measured the effect of stimulants on ADHD children, both in the electroencephalographic (EEG) activity during sustained attentional tasks and in psychometric performance during selective attentional tasks. These tasks are known to rely on different cortical networks. Our results in children medicated with 10 mg of d-amphetamine administered 60 min before the study indicate (i) a significant increase in amplitude but not latency of the P300 component of the event-related potential (ERP) during the sustained attentional task and (ii) a significant improvement in the reaction times and correct responses in the selective attentional task. In addition to supporting the use of stimulants in children with attentional deficit/hyperactivity disorder, these results show a multifocal activity improvement of cortical structures linked to dopamine, and interestingly, to attention. All these analyses are framed in a wider study of diverse attentional functions in this syndrome.

To elucidate the cognitive structures of animals, neuroscientists use several behavioral tasks. Therefore, it is imperative to have a firm understanding of each task's behavioral parameters in order to parse out possible task effects. We compare two operant discrimination tasks (Go/No-Go: GNG; Two-Alternative Choice: TAC) that are commonly used in olfactory research. Past research has suggested that solving the two tasks requires divergent cognitive strategies. One hypothesis is that the two tasks differ in how an animal optimizes reward rate by means of a speed-accuracy trade-off (SAT). If this is true, then changing tasks could give researchers an additional tool to understand animal cognition. However, no study has systematically analyzed the two tasks in parallel using odor stimuli. Using standardized training protocols, we test GNG and TAC in parallel. Our protocols allow us to isolate the stimulus sampling period from a general reaction time period. We find that the two tasks do not differ with regard to the stimulus sampling period and conclude that the two tasks do not differ in the amount of time it takes an animal to perform a discrimination. Instead, tasks differ in the time it takes to make an overt behavioral response, with GNG showing shorter periods than TAC. We also find no evidence of rats using either task-specific or intertrial interval-dependent SAT schema in order to optimize reward rate. We show that similarities between dependent variables, with the possible exception of response delay, appear to be under experimenter control.

Attention-deficit/hyperactivity disorder (ADHD) diagnosis is based on reported symptoms, which carries the potential risk of over-or under-diagnosis. A biological marker that helps to objectively define the disorder, providing information about its pathophysiology, is needed. A promising marker of cognitive states in humans is pupil size, which reflects the activity of an 'arousal' network, related to the norepinephrine system. We monitored pupil size from ADHD and control subjects, during a visuo-spatial working memory task. A sub group of ADHD children performed the task twice, with and without methylphenidate, a norepinephrine–dopamine reuptake inhibitor. Off-medication patients showed a decreased pupil diameter during the task. This difference was no longer present when patients were on-medication. Pupil size correlated with the subjects' performance and reaction time variability, two vastly studied indicators of attention. Furthermore, this effect was modulated by medication. Through pupil size, we provide evidence of an involvement of the noradrenergic system during an attentional task. Our results suggest that pupil size could serve as a biomarker in ADHD. Attention-deficit/hyperactivity disorder (ADHD) is the most prevalent childhood neuropsychiatric disorder 1, 2. This condition is characterized by inattention, impulsiveness and hyperactivity, and is becoming increasingly recognized that many patients continue having these types of difficulties in adulthood 3. Most of ADHD symptoms are related to problems in behavioral and cognitive control, and have been attributed to a deficient dopaminergic signaling 2, 4, 5. First-line treatment for ADHD is given by stimulants, mainly methylphenidate, and the usual second-line treatment is atomoxetine, a noradrenaline reuptake inhibitor 2, 6. Both kinds of drugs increase the catecholamine availability at synapses. This, together with evidence of a weak but consistent link between genetic polymorphisms associated to the catecholaminergic system and ADHD, prompted the widely accepted hypothesis that in this condition there is an underlying deficit in catecholaminergic neurotransmission 1, 7. Currently, diagnosis is being performed solely on the basis of observed behavior and reported symptoms, which carries the potential risk of over-diagnosis or under-diagnosis 6, 8. Like any complex disorder, ADHD patients display clear heterogeneities at the clinical and biological levels. These differences probably explain why some patients do not respond to medication 6–9. A biological marker that helps to objectively define the disorder, providing information about its pathophysiology and potential responses to medication, is needed 9, 10. A promising potential marker of cognitive states in humans is pupil size 11–15. After controlling for stimulus luminance, pupil size correlates with task difficulty, emotional valence, physical effort, motor output and arousal states 11, 16–21. Independent findings suggest that these fluctuations in pupil size reflect the state of the brain nor-epinephrine (NE) system 11, 22–26. This system originates in the locus-coeruleus (LC) and projects throughout the cerebral cortex, hippocampus, thalamus and midbrain, among others 22–24, 27–29. Brain areas associated with atten-tional processing (e.g., parietal cortex, pulvinar nucleus, superior colliculus) receive particularly dense LC-NE innervations 12, 25. Data from animal models, both rodents and non-human primates, have shown a central role for the LC in selective attention 11, 23–25. Published: xx xx xxxx OPEN