Two neural mechanisms related to modes of selective attention.

The use of global- and focal-attention modes to select information from a visual display is related to two neural mechanisms, visual channels and differences in the cognitive strategies directed by the cerebral hemispheres. Latencies to detect the presence of a single disparate letter in a six-letter display were measured. The results of Experiment 1 support the position that the transient visual channel transmits information for the global-attention mode, and the sustained visual channel transmits information for the focal-attention mode. Results of Experiment 2 indicate that the focal-attention mode can utilize a serial strategy directed by the dominant hemisphere.