19 research outputs found
La ansiedad estado en personas sanas puede aumentar su vulnerabilidad a la distracción neutra pero no a la desagradable en la memoria de trabajo
Se sabe que los hechos desagradables irrelevantes influyen negativamente en nuestra capacidad para mantener
en la memoria de trabajo información no emocional aunque importante para la tarea. Paralelamente,
la ansiedad sesga nuestras respuestas atencionales a aquellos estÃmulos potencialmente amenazadores
para, de este modo, mejorar adaptativamente su detección y valoración. En este trabajo hemos investigado
las diferencias entre voluntarios sanos y ansiosos mientras realizaban una tarea de memoria de trabajo en
la que se presentaban como distractores imágenes neutras y desagradables. Los resultados muestran que la
ansiedad estado puede aumentar el efecto de interferencia de los distractores neutros pero no de los desagradables.
Se comentan dichos resultados en relación a estudios anteriores que concluyen que la ansiedad
y el estrés agudo pueden disminuir el nivel de especificidad en el mecanismo de vigilancia que sirve para
optimizar la detección y evaluación de las amenazas
Early detection and late cognitive control of emotional distraction by the prefrontal cortex
Unpleasant emotional distraction can impair the retention of non-emotional information in working memory (WM). Research links the prefrontal cortex with the successful control of such biologically
relevant distractors, although the temporal changes in this brain mechanism remain unexplored. We
use magnetoencephalography to investigate the temporal dynamics of the cognitive control of both
unpleasant and pleasant distraction, in the millisecond (ms) scale. Behavioral results demonstrate
that pleasant events do not affect WM maintenance more than neutral ones. Neuroimaging results
show that prefrontal cortices are recruited for the rapid detection of emotional distraction, at early
latencies of the processing (70-130 ms). Later in the processing (360-450 ms), the dorsolateral, the
medial and the orbital sections of the prefrontal cortex mediate the effective control of emotional
distraction. In accordance with the behavioral performance, pleasant distractors do not require
higher prefrontal activity than neutral ones. These findings extend our knowledge about the brain
mechanisms of coping with emotional distraction in WM. In particular, they show for the first time
that overriding the attentional capture triggered by emotional distractors, while maintaining taskrelevant
elements in mind, is based on the early detection of such linked-to-survival information and
on its later cognitive control by the prefrontal cortex
Emotional interference-based forgetting in short-term memory. Cognitive inhibition of pleasant but not unpleasant biologically relevant distractors
Emotional stimuli automatically recruit attentional resources. Although this usually brings more adaptive responses, it may suppose a disadvantage when emotional information is task-irrelevant and should be ignored. Previous studies have shown how emotional stimuli with a negative content exert a greater interference than neutral stimuli during a concurrent working memory (WM) task. However, the impact of positively valenced stimuli as interference has not been addressed to date. In three experiments and one re-analysis we explore the impact of pleasant and unpleasant emotional distractors during WM maintenance. The results suggest that our cognitive control can cope with the interference posed by pleasant distractors as well as with the interference posed by neutral stimuli. However, unpleasant distractors are harder to control in the context of WM maintenance. As unpleasant stimuli usually convey relevant information that we should not to ignore, our executive control seems to be less able to reallocate cognitive resources after unpleasant distraction
MEG spectral analysis in subtypes of mild cognitive impairment
Mild cognitive impairment (MCI) has been described as an intermediate stage between normal aging and dementia. Previous studies characterized the alterations of brain oscillatory activity at this stage, but little is known about the differences between single and multidomain amnestic MCI patients. In order to study the patterns of oscillatory magnetic activity in amnestic MCI subtypes, a total of 105 subjects underwent an eyes-closed resting-state magnetoencephalographic recording: 36 healthy controls, 33 amnestic single domain MCIs (a-sd-MCI), and 36 amnestic multidomain MCIs (a-md-MCI). Relative power values were calculated and compared among groups. Subsequently, relative power values were correlated with neuropsychological tests scores and hippocampal volumes. Both MCI groups showed an increase in relative power in lower frequency bands (delta and theta frequency ranges) and a decrease in power values in higher frequency bands (alpha and beta frequency ranges), as compared with the control group. More importantly, clear differences emerged from the comparison between the two amnestic MCI subtypes. The a-md-MCI group showed a significant power increase within delta and theta ranges and reduced relative power within alpha and beta ranges. Such pattern correlated with the neuropsychological performance, indicating that the a-md-MCI subtype is associated not only with a "slowing" of the spectrum but also with a poorer cognitive status. These results suggest that a-md-MCI patients are characterized by a brain activity profile that is closer to that observed in Alzheimer disease. Therefore, it might be hypothesized that the likelihood of conversion to dementia would be higher within this subtype
Early prefrontal activation as a mechanism to prevent forgetting in the context of interference
Objective: Recent research has focused on interference resolution deficits as the main
cause of short-term memory decreases in aging. To determine whether activation of
brain compensatory mechanisms occur during the encoding process in older people.
Moreover, two different levels of interference (distraction and interruption) were presented
during the maintenance period to examine how they modulate brain activity
profiles. Design: A delayed match-to-sample task with two experimental conditions:
distraction and interruption. Participants: Twenty-seven young adults from Complutense
University of Madrid and 20 healthy older adults from Complutense Elderly
University of Madrid. Measurements: Magnetoencephalography scans were recorded
during the execution of a working memory interference task. Brain activity sources
from younger and older adults during the encoding stage were compared in each
condition using minimum norm estimation analyses. Results: The elderly showed
enhancement of prefrontal activity during early latencies of the encoding process in both
conditions. In the distraction condition, enhanced activity was located in left ventrolateral
prefrontal regions, whereas in the interruption condition, enhanced activity was
observed in the right ventral prefrontal areas and anterior cingulate cortex.
Conclusion: Increased recruitment of prefrontal regions in the elderly might be related
to the processing depth of information, encoding of new information and semantic
associations that are successfully recalled, and with interference resolution and preparatory
control when the level of interference becomes higher. These prefrontal modulations
during early latencies might reflect a higher top-down control of the encoding
process in normal aging to prevent forgetting
A Simple Artificial Life Model Explains Irrational Behavior in Human Decision-Making
Although praised for their rationality, humans often make poor decisions, even in simple situations. In the repeated binary choice experiment, an individual has to choose repeatedly between the same two alternatives, where a reward is assigned to one of them with fixed probability. The optimal strategy is to perseverate with choosing the alternative with the best expected return. Whereas many species perseverate, humans tend to match the frequencies of their choices to the frequencies of the alternatives, a sub-optimal strategy known as probability matching. Our goal was to find the primary cognitive constraints under which a set of simple evolutionary rules can lead to such contrasting behaviors. We simulated the evolution of artificial populations, wherein the fitness of each animat (artificial animal) depended on its ability to predict the next element of a sequence made up of a repeating binary string of varying size. When the string was short relative to the animats’ neural capacity, they could learn it and correctly predict the next element of the sequence. When it was long, they could not learn it, turning to the next best option: to perseverate. Animats from the last generation then performed the task of predicting the next element of a non-periodical binary sequence. We found that, whereas animats with smaller neural capacity kept perseverating with the best alternative as before, animats with larger neural capacity, which had previously been able to learn the pattern of repeating strings, adopted probability matching, being outperformed by the perseverating animats. Our results demonstrate how the ability to make predictions in an environment endowed with regular patterns may lead to probability matching under less structured conditions. They point to probability matching as a likely by-product of adaptive cognitive strategies that were crucial in human evolution, but may lead to sub-optimal performances in other environments
Taking the easy way out? Increasing implementation effort reduces probability maximizing under cognitive load
Desarrollo cognitivo tras un traumatisco craneoencefálico en la infancia
The occurrence of traumatic brain
injury (TBI) during childhood may disrupt ongoing brain development and,
consequently, the development of cognitive and behavioural skills.
However, cognitive and behavioural
outcome after TBI is variable, depending upon morbid and psychosocial factors. The interaction between these two
main groups of factors has been
labelled the double hazard hypothesis,
since it determines the adaptive post morbid outcome. Morbid factors include
severity of brain injury, age related variables, and the characteristics of the
damage. Psychosocial factors consist of
pre-TBI cognitive and behavioural functioning, socio-economic status, social
stress and the family resources.
Furthermore, the most frequent impairments after TBI during childhood are
slower processing speed and difficulties
in several cognitive processes, such as
attention, memory, language and executive functions. Among the latter, executive functions are especially vulnerable,
most likely due to the joint effect of several factors –high prevalence of focal
frontal lesion, disconnection effect
resulting from diffuse axonal injury,
slow maturation of frontal regions–.
Besides this high vulnerability, the
impairment of executive functions as a
consequence of TBI during childhood is
extremely relevant, since it might
underlie some of the observed deficits at
the cognitive, psychosocial and academic levels. An adequate outcome at
all these levels is critical to achieve an
adaptive behaviour.Un traumatismo craneoencefálico (TCE)
ocurrido durante la infancia puede incidir
notablemente en el proceso de desarrollo
cerebral del niño y, como consecuencia,
en su desarrollo cognitivo y conductual.
Sin embargo, la evolución de las capacidades cognitivas y conductuales tras un
TCE en la infancia no es siempre igual,
sino que depende de una serie de factores. Diversos estudios han revelado dos
grupos principales de factores que interaccionan fuertemente entre sÃ, factores mórbidos y psicosociales. Esta interacción ha sido denominada hipótesis de
doble riesgo, puesto que es la que determina el funcionamiento adaptativo postmórbido. Dentro del grupo de factores
mórbidos se incluyen la gravedad del
daño cerebral, las variables relacionadas
con la edad y las caracterÃsticas de la
lesión. Entre los factores psicosociales
destacan las caracterÃsticas cognitivas y
conductuales del niño previas al TCE y
los factores ambientales, tales como el
estatus socioeconómico, el estrés social y
los recursos y el modo de funcionamiento
de la familia.
Por otra parte, las alteraciones que más
frecuentemente se observan tras un TCE
en la infancia son el enlentecimiento de
la velocidad de procesamiento, asà como
dificultades en diversos procesos cognitivos, como la atención, la memoria, el lenguaje y las funciones ejecutivas. De entre
estos procesos, las funciones ejecutivas
son especialmente vulnerables, probablemente por el efecto conjunto de diversos
factores –elevada prevalencia de daño
focal frontal, efecto de desconexión como
resultado de la lesión axonal difusa, lenta
maduración de las regiones frontales–.
Además de su elevada vulnerabilidad, las
alteraciones en las funciones ejecutivas
como consecuencia de un TCE durante la
infancia son especialmente relevantes, ya
que podrÃan estar subyaciendo a algunos
de los déficits observados en los ámbitos
cognitivo, psicosocial y académico; y un
funcionamiento adecuado en todos estos
ámbitos es esencial para lograr un comportamiento adaptado al entorno
Aula-taller para el desarrollo de tecnologÃas básicas interdisciplinares del medio
Este proyecto propone la incorporación del aula-taller como una enseñanza práctica y dinámica frente al tradicional sistema educativo. Está dirigido principalmente al alumnado que presenta un escaso interés hacia la enseñanza reglada o al que, por sus caracterÃsticas especiales (ambiente familiar, conducta,...) necesita una actividad más dinámica en el centro. Por esto, el objetivo fundamental es facilitar el acceso a una formación de carácter más profesional, al mismo tiempo que se potencia su autoestima ante el fracaso escolar, haciéndoles sentir más útiles y capaces en otras áreas de aprendizaje. Las actividades que se plantean se desarrollan por proyectos según los diferentes talleres: construcción, pintura, campañas en defensa del medio ambiente, ornamentación del centro, etc. La evaluación mide el interés del alumnado hacia las aulas-taller y el grado de aprendizaje práctico adquirido..Madrid (Comunidad Autónoma). ConsejerÃa de Educación y CulturaMadridMadrid (Comunidad Autónoma). Subdirección General de Formación del Profesorado. CRIF Las Acacias; General Ricardos 179 - 28025 Madrid; Tel. + 34915250893ES
Understanding brain function in vascular cognitive impairment and dementia with EEG and MEG: A systematic review
CRUE-CSIC (Acuerdos Transformativos 2022)Vascular Cognitive Impairment (VCI) is the second most prevalent dementia after Alzheimer’s Disease (AD), and cerebrovascular disease (CBVD) is a major comorbid contributor to the progression of most neurodegenerative diseases. Early differentiation of cognitive impairment is critical given both the high prevalence of CBVD, and that its risk factors are modifiable. The ability for electroencephalogram (EEG) and magnetoencephalogram (MEG) to detect changes in brain functioning for other dementias suggests that they may also be promising biomarkers for early VCI. The present systematic review aims to summarize the literature regarding electrophysiological patterns of mild and major VCI. Despite considerable heterogeneity in clinical definition and electrophysiological methodology, common patterns exist when comparing patients with VCI to healthy controls (HC) and patients with AD, though there is a low specificity when comparing between VCI subgroups. Similar to other dementias, slowed frequency patterns and disrupted inter- and intra-hemispheric connectivity are repeatedly reported for VCI patients, as well as longer latencies and smaller amplitudes in evoked responses. Further study is needed to fully establish MEG and EEG as clinically useful biomarkers, including a clear definition of VCI and standardized methodology, allowing for comparison across groups and consolidation of multicenter efforts.Universidad Complutense de Madrid/Banco de SantanderMinisterio de Ciencia e Innovación (MICINN)Depto. de PsicologÃa Experimental, Procesos Cognitivos y LogopediaFac. de PsicologÃaTRUEpu