Sistemas neurales de relevancia en el contexto de la psicobiología de la ansiedad: una revisión

Resumen

La ansiedad es un estado emocional central de características muy complejas que, al menos en términos de respuesta, se asemeja en gran medida al miedo. En las ültimas décadas, estudios neurobiológicos y psicobiológicos han identificado numerosas estructuras y circuitos cerebrales estrechamente relacionados con este tipo de respuestas, así como con el estado central característico. Destacan, por su especial relevancia, el sistema límbico (incluyendo el sistema septohipocampal, la amígdala y el hipotálamo posterior) y los sistemas monoaminérgicos ascendentes (principalmente de serotonina y norepinefrina), lugares donde, además, las sustancias ansiolíticas podrían ejercer su efecto terapéutico. El principal objetivo del presente trabajo es revisar la precisa implicación de estos sistemas neurales en la modulación de ese estado emocional definido como ansiedad.     

Esfuerzo y decremento de vigilancia en tareas de discriminación sucesiva y simultánea

Resumen

El objetivo del experimento presentado en este artículo fue probar la hipótesis de que el decremento de sensibilidad en tareas de atención sostenida, ocurre porque los recursos atencionales o esfuerzo que demanda la tarea no pueden matenerse durante un tiempo prolongado. Comparamos dos tareas que diferían en carga de memoria y registramos tres grupos de índices de esfuerzo o gasto atencional: rendimiento en una tarea secundaria concurrente, esfuerzo subjetivo y actividad cardiovascular (IBI medio y amplitud espectral del componente 0.10 Hz). En ambas tareas observamos un declive significativo a lo largo del tiempo en eficiencia o ritmo de procesamiento, indicado por la razón entre la precisión y la velocidad. Los datos acerca del esfuerzo subjetivo y el rendimiento en la tarea secundaria no parecen apoyar la hipótesis original. El principal hallazgo fue que la actividad cardiovascular al comienzo de la tarea, medida por la amplitud del componente 0.1 Hz, era un predictor significativo del decremento de eficiencia en ambas tareas de vigilancia. Si esta amplitud es un índice fisiológico fiable de atención, nuestro resultado sugiere que un procesamiento controlado, con esfuerzo, al comienzo de la tarea previene el decremento de vigilancia.     

Selective interpretation in anxiety: Uncertainty for threatening events

The role of event uncertainty on inferences predictive of threat was investigated in high and low trait anxious individuals. Participants read context sentences predicting threat or nonthreat outcomes. They subsequently named target words that were consistent with or unrelated to prediction. In Experiment 1, with predictability relatively low, anxious participants showed clear threat bias in their inferences: Although nonthreat targets were unaffected by context, shorter naming latencies were found for threat target words that followed a threat predicting context. A low anxiety group showed an opposite effect, that is, facilitation only for nonthreat words, suggesting an avoidance (of threat) bias. In Experiment 2, under higher predictability, this bias disappeared, as both high and low anxious groups performed similarly. The relevance of these data for different models of selective processing in anxiety is discussed. Of particular pertinence is the finding that, with increasing stimulus threat, low anxious participants no longer show avoidance; instead, they infer threat in a way similar to the high anxious. This suggests that the difference between the high and the low anxious persons resides in the threshold at which stimulus threat input is processed.     

Reconsidering the Use of Autoregressive Latent Trajectory (ALT) Models

The simultaneous estimation of autoregressive (simplex) structures and latent trajectories, so called ALT (autoregressive latent trajectory) models, is becoming an increasingly popular approach to the analysis of change. Although historically autoregressive (AR) and latent growth curve (LGC) models have been developed quite independently from each other, the underlying pattern of change is often highly similar. In this article it is shown that their integration rests on the strong assumption that neither the AR part nor the LGC part contains any misspecification. In practice, however, this assumption is often violated due to nonlinearity in the LGC part. As a consequence, the autoregressive (simplex) process incorrectly accounts for part of this nonlinearity, thus rendering any substantive interpretation of parameter estimates virtually impossible. Accordingly, researchers are advised to exercise extreme caution when using ALT models in practice. All arguments are illustrated by empirical data on skill acquisition, and a simulation study is provided to investigate the conditions and consequences of mistaking nonlinear growth curve patterns as autoregressive processes.     

Are emotional intelligent workers also more empathic?

This paper analyzes whether emotional intelligence and self‐monitoring are related to empathy among a sample of workers in both the public and private employment sectors. Two hundred and forty‐two employees (42.5% men and 57.5% women) with a mean age of 35.21 years (SD = 10.07, range 18–61) completed a questionnaire that measured the variables of interest. The results showed that emotion regulation, a dimension of emotional intelligence, accounts for most of the variance of empathy, followed by the ability to understand emotions and the management of others' emotions. Furthermore, gender did not yield any moderator effect on the relations among emotional intelligence, self‐monitoring and empathy. We conclude that the intrapersonal aspects of emotional intelligence, in particular, emotion regulation, help explain the empathy of workers. The implications of these findings are discussed herein.     

Can the eyes reveal a person’s emotions? Biasing role of the mouth expression

In this study we investigated how perception of the eye expression in a face is influenced by the mouth expression, even when only the eyes are directly looked at. The same eyes appeared in a face with either an incongruent smiling, angry, or sad mouth, a congruent mouth, or no mouth. Attention was directed to the eyes by means of cueing and there were no fixations on the mouth. Participants evaluated whether the eyes were happy (or angry, or sad) or not. Results indicated that the smile biased the evaluation of the eyes towards happiness to a greater extent than an angry or a sad mouth did towards anger or sadness. The smiling mouth was also more visually salient than the angry and the sad mouths. We conclude that the role of the eyes as a “window” to a person’s emotional and motivational state is constrained and distorted by the configural projection of an expressive mouth, and that this effect is enhanced by the high visual saliency of the smile.     

Environmental sound recognition by timbre in children with Williams syndrome

Anecdotal reports have described children with Williams syndrome (WS) as presenting outstanding skills for recognizing environmental sounds by their timbre. This has led to suggest that the skills for environmental sound recognition by timbre are highly developed in WS. Furthermore, the term hypertimbria has been proposed to refer to this feature. However, no academic research has assessed these skills in WS. This study therefore aimed to contrast the reports on the highly developed skills for environmental sound recognition by timbre in children with WS. An environmental sound recognition task was administered to children with WS, children with Down syndrome of the same chronological age and cognitive level, and chronological age-matched typically developing children. Participants with WS performed significantly lower than their typically developing peers and no significant differences were found between the WS and Down syndrome groups. Unlike previous reports, this study points out that in WS environmental sound recognition by timbre does not constitute a phenotypic strength either in absolute or relative terms. Results suggest that children with WS do not present hypertimbria or preserved skills for timbre recognition. We discuss the implications of these results for theories of cognitive modularity.     

Test anxiety and comprehension efficiency: The role of prior knowledge and working memory deficits

The hypotheses that test anxiety is associated with a deficit in prior knowledge and/or working memory capacity, that anxiety impairs comprehension efficiency, and that deficits in knowledge and capacity underlie the efficiency impairment, were tested. In Study 1, high-anxiety students were characterized by lower scores in several vocabulary measures, compared with low-anxiety students. In Study 2, high-anxiety individuals showed inferior working memory capacity to low-anxiety individuals under evaluative stress conditions, but not under non-stress conditions. In Study 3 high-anxiety subjects exhibited lower efficiency scores than low-anxiety subjects in expository texts without a summary: The former employed a greater amount of reading time than the latter to acquire an equivalent amount of information. In addition, the disadvantage in efficiency associated with anxiety was removed when differences in vocabulary knowledge were partialled out statistically. Instead, that disadvantage was only reduced, but not eliminated, when differences in transitory working memory capacity were partialled out. Therefore, the prior knowledge deficit hypothesis accounts for the impairment in reading efficiency associated with high anxiety better than the transitory working memory reduction hypothesis.     

Recognition memory deficits in mild cognitive impairment

ABSTRACT

There is no agreement on the pattern of recognition memory deficits characteristic of patients diagnosed with mild cognitive impairment (MCI). Whereas lower performance in recollection is the hallmark of MCI, there is a strong controversy about possible deficits in familiarity estimates when using recognition memory tasks. The aim of this research is to shed light on the pattern of responding in recollection and familiarity in MCI. Five groups of participants were tested. The main participant samples were those formed by two MCI groups differing in age and an Alzheimer's disease group (AD), which were compared with two control groups. Whereas one of the control groups served to assess the performance of the MCI and AD people, the other one, composed of young healthy participants, served the purpose of evaluating the adequacy of the experimental tasks used in the evaluation of the different components of recognition memory. We used an associative recognition task as a direct index of recollection and a choice task on a pair of stimuli, one of which was perceptually similar to those studied in the associative recognition phase, as an index of familiarity. Our results indicate that recollection decreases with age and neurological status, and familiarity remains stable in the elderly control sample but it is deficient in MCI. This research shows that a unique encoding situation generated deficits in recollective and familiarity mechanisms in mild cognitive impaired individuals, providing evidence for the existence of deficits in both retrieval processes in recognition memory in a MCI stage.