Exposure to traumatic events and perceptual priming in forcedly displaced Colombian population in Ecuador

Los recientes estudios en priming perceptivo se han centrado en identificar las diferencias entre población con y sin Trastorno por Estrés Postraumático (TEPT) confirmando la hipótesis que el TEPT representa un trastorno de la memoria. En este trabajo, se pretende abordar el priming en personas que han estado expuestas a diversas experiencias traumáticas relacionadas con el desplazamiento forzado. Para ello se diseñaron tres categorías de palabras “trauma” (i.e., de amenaza, emocional y judicial) y una categoría de palabras “neutra”, las cuales compartían su raíz de tres letras en 44 colombianos refugiados y solicitantes de asilo que residen en Ecuador con presencia o ausencia de TEPT. Los resultados confirman que las personas con TEPT presentan mayor priming perceptivo en las categorías de amenaza y emociones y los solicitantes de asilo en la categoría judicial. Se discuten las implicaciones para los estudios que abordan el impacto de violencia política. In line with the hypothesis that PTSD is a memory disorder, recent studies on perceptual priming have focused on identifying the differences between population with and without Post-Traumatic Stress Disorder (PTSD). This study addresses priming in people who have been exposed to traumatic experiences of forced displacement. To that end, three categories of the word “trauma” (i.e., of threat, emotional and judicial) and a category of “neutral” words, which shared their three-letter root were chosen. The participants were 44 Colombian refugees and asylum seekers living in Ecuador with or without PTSD. The results of our study point that people with PTSD have higher perceptual priming in the threat and emotional categories, and asylum seekers show higher priming in the judicial category. The implications for studies that address the impact of political violence are discussed.

Bistable Perception Is Biased by Search Items but Not by Search Priming

During visual search, selecting a target facilitates search for similar targets in the future, known as search priming. During bistable perception, in turn, perceiving one interpretation facilitates perception of the same interpretation in the future, a form of sensory memory. Previously, we investigated the relation between these history effects by asking: can visual search influence perception of a subsequent ambiguous display and can perception of an ambiguous display influence subsequent visual search? We found no evidence for such influences, however. Here, we investigated one potential factor that might have prevented such influences from arising: lack of retinal overlap between the ambiguous stimulus and the search array items. In the present work, we therefore interleaved presentations of an ambiguous stimulus with search trials in which the target or distractor occupied the same retinal location as the ambiguous stimulus. Nevertheless, we again found no evidence for influences of visual search on bistable perception, thus demonstrating no close relation between search priming and sensory memory. We did, however, find that visual search items primed perception of a subsequent ambiguous stimulus at the same retinal location, regardless of whether they were a target or a distractor item: a form of perceptual priming. Interestingly, the strengths of search priming and this perceptual priming were correlated on a trial-to-trial basis, suggesting that a common underlying factor influences both.