A neutral cue facilitates detection of a visual target by modulating attention.

Twelve rats were trained to perform a two-choice visual detection task in which a right or left light was presented and the animals were required to press the lever located under the illuminated light for a food reward. In seventy percent of the trials the target light was preceded by presentation of a neutral cue (a central light). Relevance of the neutral cue for detection of the target was analyzed by comparing behavioral Indices of attention in its presence and absence. Accuracy was significantly higher in presence than in absence of the neutral cue, while mean response latencies were lower in presence than in absence of the neutral cue. These results indicate that the animals allocated attentional resources on the target detection during a high expectancy period after the onset of the neutral cue. This could facilitate target detection and improve the performance in the presence of the neutral cue.