Abstract
Rationale: Spatial attention increases contrast sensitivity and spatial resolution at attended locations and decreases them at unattended locations. Temporal attention improves performance at a specific given moment and decreases it at unattended moments. Most psychophysical experiments study attentional mechanisms in isolation, but in everyday life, they work together to optimize behavior. Here we investigate whether and how spatial and temporal attention benefit performance together while maximizing their independent effects and measuring their combined effect all in the same task. Here we investigate how spatial and temporal attention interact. Methods: In a 2AFC task, observers (n = 12) reported the orientation of a tilted Gabor. We manipulated observers’ spatial and temporal attention with precues (valid, neutral, or invalid) that indicated the most likely side (lower left or right) and timing (time one or two) of the tested target. We measured performance (d′) and reaction times for every combination of spatial and temporal cue. We measured the isolated effects of temporal and spatial attention to establish a baseline for comparison with the conjoint effect. Results: Spatial attention has clear benefit and cost effects across temporal attention conditions. Temporal attention benefits on accuracy are small across spatial attention conditions, but decreases reaction times across all spatial attention conditions. We also fit a computational model to these data, which models attentional encoding of the stimulus and late noise on the perceptual decision. Conclusions: These results suggest that people rely more on spatial attention than on temporal attention.