Sensory Memory Capacity and Duration

Capacity: Sensory memory is considered unlimited in capacity because it must hold all incoming sensory information.
Function: Maintains a large amount of information very briefly so the world is experienced as a continuous stream of information rather than discrete sensations (refer to Table 7.1).
Visual Continuity: Visual sensory memory "fills in" visual information for about one third of a second when blinking; closing eyes longer results in darkness because the blink duration exceeds sensory memory duration.

Whole Report Method: Three rows of four letters ( $12$ letters total) were flashed on a screen for one twentieth of a second (Figure 7.7a). Participants recalled only three or four letters, as the remaining eight or nine letters faded during recall.
Partial Report Method: Participants were asked to report just one row based on hearing a high-pitched, medium-pitched, or low-pitched sound played immediately after the letters disappeared (refer to Figure 7.7a).
Partial Report Results: Participants remembered almost all letters in the signaled row when the sound occurred immediately, but recalled fewer letters as the delay before the sound increased.
Duration Conclusion: Participants maintain many of the $12$ items in sensory storage for about one third of a second (Figure 7.7b, green line), after which the trace fades progressively until inaccessible.