Spatial ranking strategy and enhanced peripheral vision discrimination optimize performance and efficiency of visual sequential search

Abstract

Visual sequential search might use a peripheral spatial ranking of the scene to put the next target of the sequence in the correct order. This strategy, indeed, might enhance the discriminative capacity of the human peripheral vision and spare neural resources associated with foveation. However, it is not known how exactly the peripheral vision sustains sequential search and whether the sparing of neural resources has a cost in terms of performance. To elucidate these issues, we compared strategy and performance during an alpha-numeric sequential task where peripheral vision was modulated in three different conditions: normal, blurred, or obscured. If spatial ranking is applied to increase the peripheral discrimination, its use as a strategy in visual sequencing should differ according to the degree of discriminative information that can be obtained from the periphery. Moreover, if this strategy spares neural resources without impairing the performance, its use should be associated with better performance. We found that spatial ranking was applied when peripheral vision was fully available, reducing the number and time of explorative fixations. When the periphery was obscured, explorative fixations were numerous and sparse; when the periphery was blurred, explorative fixations were longer and often located close to the items. Performance was significantly improved by this strategy. Our results demonstrated that spatial ranking is an efficient strategy adopted by the brain in visual sequencing to highlight peripheral detection and discrimination; it reduces the neural cost by avoiding unnecessary foveations, and promotes sequential search by facilitating the onset of a new saccade.

A Mixed Statistical and Machine Learning Approach for the Analysis of Multimodal Trail Making Test Data

“…In the VSST setting, the patients are required to carry on the same task based only on eye movements. Human visual search [20,21] is, in fact, a common activity that enables humans to explore the external environment to take everyday life decisions. Indeed, sequential visual search should use a peripheral spatial scene classification technique to put the next target in the sequence in the correct order, a strategy which, as a byproduct, could also improve the discriminatory ability of human peripheral vision and save neural resources associated with foveation.…”

Contribuciones del Rastreo Ocular al Test de Percepción de Diferencias: Un Estudio en Población Universitaria

“…Desde ese momento y hasta la actualidad se produce un gran incremento en las investigaciones y publicaciones, gracias a la comodidad de estas herramientas y a su accesibilidad, en las cuales se utilizan muchas y variadas técnicas de seguimiento ocular, la mayoría no invasivas para el sujeto y de fácil implementación (Blascheck et al, 2014;Duchowski, 2002;Eckstein et al, 2017;Kowler, 2011). Por estos motivos, el ET se ha transformado en un dispositivo valioso en el diagnóstico y evaluación de muchas patologías neurológicas (Armstrong & Olatunji, 2012;Buedo et al, 2018;Rosa et al, 2018) y neuropsicológicas (Antoniades & Kennard, 2015;Crutcher et al, 2009;Cuesta-Cambra et al, 2017;Goldberg & Wichansky, 2003;Hicks et al, 2013;Lencer et al, 2017;Poletti et al, 2017;Veneri et al, 2014) Hoy en día la tecnología de ET permite y facilita la realización de variados y precisos estudios, aun bajo situaciones en las que se permite una considerable libertad de movimiento al sujeto evaluado. Asimismo, los datos obtenidos proporcionan una gran precisión en el análisis de los elementos que caracterizan la mirada.…”