Biomedical subjects

Manuel J Blanco

Publications and source records attributed to Manuel J Blanco.

3 recordsLinked to original sources

PubMed2005

Early, involuntary top-down guidance of attention from working memory.

Four experiments explored the interrelations between working memory, attention, and eye movements. Observers had to identify a tilted line amongst vertical distractors. Each line was surrounded by a colored shape that could be precued by a matching item held in memory. Relative to a neutral baseline, in which no shapes matched the memory item, search was more efficient when the memory cue matched the shape containing the target, and it was less efficient when the cued stimulus contained a distractor. Cuing affected the shortest reaction times and the first saccade in search. The effect occurred even when the memory cue was always invalid but not when the cue did not have to be held in memory. There was also no evidence for priming effects between consecutive trials. The results suggest that there can be early, involuntary top-down directing of attention to a stimulus matching the contents of working memory.

Adolescent↗

PubMed2004

Spatial attention and object-based attention: a comparison within a single task.

There is now much experimental evidence supporting the idea that visual attention can be deployed in at least two ways: one space-based and other object-based. However, it is not clear whether space- and object-based attention work in an integrated way within the visual system. In this article, we present two experiments in which we compare both components of attention within a cueing paradigm. Participants had to discriminate the orientation of a line that appeared within one of four moving circles, differing in colour. A cue appearing close to one of the four circles indicated the location or circle where the target stimulus was likely to appear. Spatial and object cueing effects were observed: responses were faster when target appeared either at the precued location or within the precued object. In addition, the object-cueing effect occurred only when the cue was spatially invalid and not when it was spatially valid. These results suggest that object- and space-based attention interact, with selection by location being primary over object-based selection.

Adult↗

PubMed2002

Effects of spatial attention on detection and identification of oriented lines.

In this paper, we study the effects of spatial attention on detection and identification of oriented lines presented at near-threshold luminance. In the first experiment, we found that the cuing effect was greater when observers had to discriminate between two close orientations than when they had to discriminate between two far-apart orientations. In the second experiment, we examined the effects of peripheral cues on summation of low-contrast oriented lines. We found that the range of orientations within which summation occurred was greater when the cues were invalid than when they were valid. Our results suggest that attention to a specific location in the visual field modulates the neural channels which code orientation in at least two different ways: (a) spatial attention increases the responsivity of these channels to stimuli presented at this location, and (b) it reduces the bandwidths or ranges of orientations to which these channels are sensitive. These results suggest that the properties of the orientation-tuned channels, including those that seem to exert their effects at early stages of orientation processing (e.g., tuning function), may not be fixed, but rather vary according to the attention being paid to the spatial region within which the target stimulus is presented.

Adult↗