CBSE Class 11 Psychology Chapter 7: Human Memory NCERT Solutions

Solution: Memory is understood as a process that involves three distinct, yet interconnected, stages. These stages are:

1. Encoding: This is the initial stage where incoming information is registered and processed so that it can be utilized by our memory system. During encoding, information is received, and some form of meaning is derived from it.
2. Storage: This is the second stage, crucial for retaining information over a period. Storage refers to the process by which encoded information is maintained and held for later use.
3. Retrieval: This is the third and final stage. Information can only be used when it is successfully recovered from memory. Retrieval involves bringing stored information back into conscious awareness to perform cognitive tasks.

Solution: The Atkinson and Shiffrin model, also known as the stage model of memory, proposes that information is processed through three sequential memory systems: sensory memory, short-term memory (STM), and long-term memory (LTM).

1. Sensory Memory: This system holds a very brief impression of sensory stimuli (like sights or sounds). It has a large capacity but a very short duration, typically less than a second. It acts as an initial buffer for incoming sensory information.

2. Short-Term Memory (STM): Information that is attended to from sensory memory moves to STM. It holds a limited amount of information for a brief period, usually less than 30 seconds, unless rehearsed. STM is primarily encoded acoustically and has a small capacity.

3. Long-Term Memory (LTM): Information from STM can be transferred to LTM through processes like elaborative rehearsal. LTM serves as a more permanent store for memories, with a virtually unlimited capacity and information encoded semantically. This is where memories are stored for later retrieval.

Each memory system differs in its information processing methods, capacity, and duration of storage.

Solution: Maintenance rehearsals and elaborative rehearsals are two distinct strategies for processing information in memory:

Maintenance Rehearsals: These are control processes primarily used in Short-Term Memory (STM) to retain information for a desired period. Maintenance rehearsal involves simple repetition, either silently or vocally. As the name suggests, it merely maintains the information in STM. If these repetitions stop, the information is typically lost. It does not involve deep processing or deriving meaning.

Elaborative Rehearsals: These rehearsals are crucial for transferring information from STM to Long-Term Memory (LTM). Elaborative rehearsal involves actively connecting the information to be remembered with existing knowledge already stored in LTM. This process requires deeper analysis, assigning meaning, and forming associations. Examples include organizing information logically, linking it to similar memories, or creating mental images. This method leads to more robust and lasting memories.

Solution: Declarative and procedural memories are two major types of long-term memory, differing in the nature of the information they store:

Declarative Memory: This type of memory stores explicit information about facts, concepts, events, and general knowledge. It includes information that can be easily verbalized or declared. Examples include knowing that a bicycle has two wheels, the date of India's independence, or the definition of a word. Facts stored in declarative memory are amenable to verbal description.

Procedural Memory: This type of memory stores implicit information related to skills, habits, and how to perform various tasks. It is often referred to as 'knowing how' rather than 'knowing that'. Examples include riding a bicycle, typing on a keyboard, or playing a musical instrument. These memories are typically acquired through practice and are often difficult to explain verbally but are demonstrated through performance.