Biomedical subjects

Valia Rodríguez

Publications and source records attributed to Valia Rodríguez.

3 recordsLinked to original sources

PubMed2006

Sensory suppression during shifts of attention between surfaces in transparent motion.

During transparent motion, attention to changes in the direction of one illusory surface will impede recognition of a similar event affecting the other surface if both are close together in time. This is a form of object-based attentional blink (AB). Here, we show that this AB is related to a smaller N200 response to the change in direction and that the response is even smaller for trials on which the subject makes mistakes compared to those with correct responses consistent with signal detection theory models. The variation of N200 associated with the AB can be modeled by an attenuation of current sources estimated in visual extrastriate cortex. These results suggest that the AB in the transparent motion paradigm is due to the suppression of sensory signals in early visual areas.

Adult↗

PubMed2004

Two-object attentional interference depends on attentional set.

In this study, we explored the influence of an irrelevant translational event on the automatic capture of attention to one of two superimposed surfaces defined by transparent motion. The results showed that an irrelevant translation on one surface did not automatically capture the subjects' attention if the attentional resources have been endogenously allocated on the other surface. Moreover, the reduction in the motion-onset component of the event-related potential observed in trials where the irrelevant event affected the uncued surface supports the existence of a top-down control of early sensorial processing in this paradigm. This study provides further evidence of the interaction of stimulus-driven and goal-directed mechanisms in the control of visual attention.

Adult↗

PubMed2002

Dividing attention between form and motion during transparent surface perception.

Attending to objects implies the concurrent process of features that are analyzed in different visual subsystems or domains. Previous works have shown that attention cannot be simultaneously directed to the components of motion present in two transparent surfaces [M. Valdés et al., Cognition 66 (1998) B13-B23], even though they occupy overlapping regions of space. In this paper, possible across-domain effects in object-based attention were examined using a conjunction of form and motion in transparent superimposed surfaces. After directing attention to one surface, different combinations of motion and form judgements were performed. If both attributes belonged to the same surface, no interference was found. If the two judgements concerned features from different surfaces, a large performance cost was present for the attribute belonging to the uncued surface. The fact that these effects cut across feature domains supports the integrated competition hypothesis [J. Duncan, Attention and Performance XVI, The MIT Press, 1996, pp. 549-578].

Adult↗