Final answer:
George Sperling's partial report experiments demonstrated that people can recall more information from a single glance than previously thought, showing a larger capacity of sensory memory. This information fades unless transferred to short-term memory, challenging the understanding of sensory memory's limitations at the time.
Step-by-step explanation:
George Sperling's experiments with the partial report paradigm were critical in enhancing our understanding of sensory memory, particularly iconic memory. His findings primarily indicated that people can recall more information from a single glance than was previously thought. This contradicts the common belief that our sensory memory's storage is very limited and falls into decay quickly.
During Sperling's experiments, he flashed a grid of letters for a very short period and asked participants to recall as many letters as possible. The full report condition, where participants were asked to recall all the letters, yielded fewer recalled letters compared to the partial report condition, where only a random row of letters was requested immediately after the display vanished. This demonstrated that a large amount of visual information is temporarily available in the sensory memory and can be retrieved if cued promptly.
The partial report technique led to the conclusion that the complete grid of letters was available in sensory memory but that this information fades very rapidly, within a second or two. Hence, Sperling was able to prove that the capacity of sensory memory was larger than previously thought but that this information decays quickly unless attended to and transferred to short-term memory (STM).
While memory trace decay over time is a known phenomenon, as shown in Ebbinghaus's forgetting curve and Peterson and Peterson's work on trigrams, Sperling's work specifically illustrated the previously unrecognized capacity of sensory memory. He did not, however, find that iconic memory is longer-lasting than echoic memory (sensory memory for sounds) or directly address the effects of interference on sensory memory.