EXPRESS: Can arrows change the subjective perception of space? Exploring symbolic attention repulsion

The attention repulsion effect (ARE) refers to distortions in the perception of space for areas nearby the focus of attention. For instance, when attending to the right-hand side of the visual field, objects in central vision may appear as though they are shifted to the left. The phenomenon is likely caused by changes in visual cell functioning. To date, research on the ARE has almost exclusively used exogenous manipulations of attention. In contrast, research exploring endogenous attention repulsion has been mixed, and no research has explored the effects of non-predictive arrow cues on this phenomenon. This gap in the literature is unexpected, as symbolic attention appears to be a unique form of attentional orienting compared to endogenous and exogenous attention. Therefore, the current study explored the effects of symbolic orienting on spatial repulsion and compared it to an exogenously generated ARE. Across four experiments, both exogenous and symbolic orienting resulted in AREs; however, the magnitude of the symbolic ARE was smaller than the exogenous ARE. This difference in magnitude persisted, even after testing both phenomena using stimulus timing parameters known to produce optimal effects in traditional attentional cueing paradigms. Therefore, compared to symbolic attention, it appears that exogenous manipulations may tightly constrict attention resources on the cued location, in turn potentially influencing the functioning of visual cells for enhanced perceptual processing.

Disrupted Spatial Organization of Cued Exogenous Attention Persists Into Adulthood in Developmental Dyslexia

Purpose: Abnormal exogenous attention orienting and diffused spatial distribution of attention have been associated with reading impairment in children with developmental dyslexia. However, studies in adults have failed to replicate such relationships. The goal of the present study was to address this issue by assessing exogenous visual attention and its peripheral spatial distribution in adults with developmental dyslexia.Methods: We measured response times, accuracy and eye movements of 18 dyslexics and 19 typical readers in a cued discrimination paradigm, in which stimuli were presented at different peripheral eccentricities.Results: Results showed that adults with developmental dyslexia were slower that controls in using their mechanisms of exogenous attention orienting. Moreover, we found that while controls became slower with the increase of eccentricity, dyslexics showed an abnormal inflection at 10° as well as similar response times at the most distant eccentricities. Finally, dyslexics show attentional facilitation deficits above 12° of eccentricity, suggesting an attentional engagement deficit at far periphery.Conclusion: Taken together, our findings indicate that, in dyslexia, the temporal deficits in orientation of attention and its abnormal peripheral spatial distribution are not restricted to childhood and persist into adulthood. Our results are, therefore, consistent with the hypothesis that the neural network underlying selective spatial attention is disrupted in dyslexia.

An image-computable model of how endogenous and exogenous attention differentially alter visual perception

Attention alters perception across the visual field. Typically, endogenous (voluntary) and exogenous (involuntary) attention similarly improve performance in many visual tasks, but they have differential effects in some tasks. Extant models of visual attention assume that the effects of these two types of attention are identical and consequently do not explain differences between them. Here, we develop a model of spatial resolution and attention that distinguishes between endogenous and exogenous attention. We focus on texture-based segmentation as a model system because it has revealed a clear dissociation between both attention types. For a texture for which performance peaks at parafoveal locations, endogenous attention improves performance across eccentricity, whereas exogenous attention improves performance where the resolution is low (peripheral locations) but impairs it where the resolution is high (foveal locations) for the scale of the texture. Our model emulates sensory encoding to segment figures from their background and predict behavioral performance. To explain attentional effects, endogenous and exogenous attention require separate operating regimes across visual detail (spatial frequency). Our model reproduces behavioral performance across several experiments and simultaneously resolves three unexplained phenomena: 1) the parafoveal advantage in segmentation, 2) the uniform improvements across eccentricity by endogenous attention, and 3) the peripheral improvements and foveal impairments by exogenous attention. Overall, we unveil a computational dissociation between each attention type and provide a generalizable framework for predicting their effects on perception across the visual field.

Señales de amenaza y sesgo atencional en lafobia a la sangre, inyecciones y heridasy en la fobia a las serpientes

El objetivo de esta investigación fue estudiar el efecto de una señal que indica la aparición de una imagen fóbica sobre la actividad electrocortical provocada por el estímulo relevante para el trastorno en la fobia a la sangre por lesión en inyección (BII) y la fobia a las serpientes. Una muestra de 13 participantes con fobia BII, 12 individuos con fobia a las serpientes y 14 controles no fóbicos se sometieron a una tarea S1-S2, donde S1 era una palabra que describía el contenido de una imagen posterior (relacionada con la sangre, serpiente y neutral) que apareció 2 segundos después (S2). Obtuvimos las amplitudes ERP P200 y P300 provocadas por las imágenes. Nuestros resultados revelan que P200 no diferenciaba entre el contenido de las imágenes en la fobia BII mientras que, por el contrario, las imágenes relacionadas con la serpiente y la sangre provocaron las respuestas más grandes en los participantes con fobia a las serpientes. Tanto las imágenes relacionadas con la sangre como las de serpientes provocaron amplitudes de P300 mayores que las imágenes neutrales en todos los grupos. Las señales de amenaza redujeron la reacción electrocortical del BII, posiblemente por la provocación de respuestas anticipatorias o reguladoras. Estos resultados son indicativos de una baja atención automática exógena hacia los estímulos temidos en la fobia BII, como lo revela P200, probablemente relacionado con una falta de sesgo de atención al objeto fóbico. The aim of this research was to study the effect of a cue signalling the upcoming of a phobic picture on the electrocortical activity provoked by the disorder-relevant stimulus in in blood-injection-injury (BII) phobia and snake phobia. A sample of 13 BII phobia participants, 12 snake phobia individuals and 14 non-phobic controls underwent an S1-S2 task, where S1 was a word that described the content of a subsequent picture (blood-related, snake and neutral) that appeared 2 seconds later (S2). We obtained the P200 and P300 ERP amplitudes provoked by the pictures. Our results reveal that P200 did not differentiate between picture contents in BII phobia while, in contrast, snake and blood-related pictures provoked the largest responses in snake phobia participants. Both blood-related and snake pictures provoked greater P300 amplitudes than neutral pictures in all the groups. Threat cues reduced the electrocortical reaction of the BII, possibly by the elicitation of anticipatory or regulatory responses. These results are indicative of a low automatic, exogenous attention towards the feared stimuli in BII phobia, as revealed by P200, probably related to a lack of attentional bias to the phobic object.