Final answer:
15 seconds, Short-term memory, as defined by cognitive psychology, has a limited duration unless actively rehearsed. Research indicates that, on average, information placed in short-term memory tends to be lost within approximately 15 seconds if not repeated. This phenomenon is known as the decay of short-term memory.
Step-by-step explanation:
Short-term memory has a limited capacity and duration. According to research, unless information is actively rehearsed or repeated, it tends to fade away within about 15 seconds. This phenomenon is known as the decay of short-term memory. The decay theory suggests that memories not being used or reinforced gradually disappear. In the context of this question, the correct option is 15 seconds, as it aligns with the general understanding of the limited retention span of information in short-term memory.
Short-term memory is a temporary storage system for information that is being actively processed. The capacity of short-term memory is estimated to be around 7 items, plus or minus 2, according to George A. Miller's classic study. The duration of information in short-term memory is influenced by factors such as rehearsal and interference. Rehearsal, or the process of repeating information, helps to maintain it in short-term memory for a longer duration.
In this case, the correct answer, option b (15 seconds), is derived from the understanding that without active repetition or rehearsal, information in short-term memory tends to dissipate within this timeframe. It emphasizes the importance of consciously reinforcing information to retain it beyond the typical short-term memory duration.