NCERT Solutions for Class 11 Psychology Chapter 6: Human Memory (NCERT 2026–27)
These Class 11 Psychology Chapter 6 solutions cover Human Memory from the NCERT Psychology textbook for the 2026–27 session. The chapter explains the nature of memory as a three-stage process of encoding, storage and retrieval; the Stage Model of Atkinson and Shiffrin with its sensory, short-term and long-term memory systems; the levels of processing view; types of long-term memory (declarative/procedural and episodic/semantic); the nature and causes of forgetting (trace decay, interference and retrieval failure); and strategies for enhancing memory (mnemonics using images and organisation). Below you get step-by-step answers to all seven Review Questions, plus key terms, extra practice, MCQs, Assertion–Reason questions and FAQs.
Class: 11Subject: PsychologyChapter: 6Chapter Name: Human MemoryExercise: Review QuestionsSession: 2026–27
Chapter 6, Human Memory, studies how information is committed to memory, retained over time, lost and improved. Memory is defined as the retaining and recalling of information and is conceptualised as a process of three interrelated stages — encoding (recording and registering information), storage (holding it over time) and retrieval (bringing it back to awareness). The first model, the Stage Model (Atkinson and Shiffrin, 1968), compares memory to a computer and proposes three stores: a large but very brief sensory memory, a fragile short-term memory (STM, capacity 7±2, duration under 30 seconds), and a permanent long-term memory (LTM). Control processes such as selective attention, maintenance rehearsal, chunking and elaborative rehearsal move information between stores. The levels of processing view (Craik and Lockhart, 1972) argues that the deeper (more semantic) the encoding, the better the retention. LTM is classified into declarative/procedural and episodic/semantic memory. Forgetting is explained by trace decay, interference (proactive and retroactive) and retrieval failure. Finally, the chapter offers memory-enhancing mnemonics — the keyword method, method of loci, chunking, first-letter technique and deep processing.
Key Terms & Concepts
Memory: the process of retaining and recalling information over a period of time; central to perception, thinking and problem solving.
Encoding, storage, retrieval: the three stages of memory — recording information so it is usable, holding it over time, and bringing it back to awareness. Memory failure can occur at any stage.
Stage Model: proposed by Atkinson and Shiffrin (1968); treats memory like a computer with three stores — sensory memory, short-term memory and long-term memory.
Sensory memory (sensory register): large-capacity store of very short duration (less than a second) that registers exact replicas of stimuli — e.g. iconic (visual) and echoic (auditory) registers.
Short-term memory (STM): holds a small amount of attended information for about 30 seconds, encoded mainly acoustically; capacity 7±2 items, expandable by chunking.
Long-term memory (LTM): a permanent store of vast (unlimited) capacity; information is encoded semantically and is said to be never lost — what we call forgetting is largely retrieval failure.
Working memory (Baddeley, 1986): view of STM as an active ‘work bench’ with a phonological loop, a visuospatial sketchpad and a central executive.
Control processes: selective attention, maintenance rehearsal, chunking and elaborative rehearsal — mechanisms that move information between stores.
Levels of processing (Craik and Lockhart, 1972): retention depends on the depth of processing — structural (shallowest), phonetic (intermediate) and semantic (deepest, best retained).
Declarative vs procedural memory: declarative holds facts, names and dates (verbally describable); procedural holds skills like riding a bicycle (hard to describe in words).
Episodic vs semantic memory: episodic stores personal, dated, often emotional life events; semantic stores general knowledge, concepts and rules — affect-neutral and not dated.
Forgetting — trace decay, interference, retrieval failure: traces fading through disuse; proactive (forward) and retroactive (backward) interference between associations; and the absence or inappropriateness of retrieval cues.
Mnemonics: strategies for improving memory — keyword method, method of loci, chunking, first-letter technique (e.g. VIBGYOR), deep-level processing and the PQRST method.
“Review Questions” — Full Solutions
All questions below are reproduced verbatim from the NCERT textbook’s end-of-chapter Review Questions section. Answers are original, written in exam-ready style.
1. What is the meaning of the terms ‘encoding’, ‘storage’ and ‘retrieval’?
ANSWERMemory is conceptualised as a process made up of three independent yet interrelated stages, and these three terms name those stages.Encoding is the first stage. It is the process by which information is recorded and registered for the first time so that it becomes usable by the memory system. When a stimulus impinges on our sense organs, it generates neural impulses; in encoding this incoming information is received, given some meaning and represented in a form that can be processed further.Storage is the second stage. Information that has been encoded must be held so that it can be used later. Storage therefore refers to the process through which information is retained and maintained over a period of time.Retrieval is the third stage. It refers to bringing the stored information back into one’s awareness so that it can be used to perform cognitive tasks such as problem solving or decision-making. Memory failure can occur at any of these three stages — faulty encoding, weak storage, or an inability to retrieve.
2. How is information processed through sensory, short-term and long-term memory systems?
ANSWERAccording to the Stage Model of Atkinson and Shiffrin, information flows through three stores, each with different capacity and duration.Sensory memory: incoming information first enters the sensory register, which has a very large capacity but an extremely short duration (less than a second). It holds an exact replica of the stimulus — for example iconic (visual) and echoic (auditory) traces — which decay automatically unless attended to.Short-term memory (STM): information that receives selective attention passes from the sensory register into the STM, which holds a small amount of information (about 7±2 items) for roughly 30 seconds, encoded mainly acoustically. Through maintenance rehearsal the information is retained for as long as needed, and through chunking its limited capacity can be expanded.Long-term memory (LTM): material that survives the capacity and duration limits of STM enters the LTM through elaborative rehearsal, which connects the new information to existing knowledge. The LTM is a permanent store of unlimited capacity in which information is encoded semantically. Thus information travels sensory register → STM → LTM, with attention and the various rehearsals acting as control processes that govern the flow.
3. How are maintenance rehearsals different from elaborative rehearsals?
ANSWERMaintenance rehearsal simply retains information in the short-term memory by repeating it through silent or vocal repetition. It does not add meaning; the information is kept alive only as long as the repetition continues, and once repetition stops the information is lost. It helps hold material in STM for a brief period.Elaborative rehearsal, on the other hand, transfers information from the STM into the long-term memory. Instead of mere repetition, it attempts to connect the ‘to be retained’ information to information already present in the LTM — by expanding it in a logical framework, linking it to similar memories or forming a mental image. The greater the number of associations created, the more permanent the memory.In short, maintenance rehearsal keeps information in STM through repetition, whereas elaborative rehearsal deepens and organises the information by association and moves it into long-term, durable storage.
4. Differenciate between declarative and procedural memories?
ANSWERDeclarative and procedural memory are two major types of long-term memory.Declarative memory contains all the information pertaining to facts, names and dates — for example that a rickshaw has three wheels, that India became independent on 15 August 1947, or that a frog is an amphibian. Such facts are amenable to verbal description; we can state them in words.Procedural memory (sometimes called non-declarative memory) refers to memories of procedures and skills for accomplishing tasks — such as how to ride a bicycle, make tea or play basketball. The contents of procedural memory cannot be described easily in words; for instance, you can describe how cricket is played, but you would find it difficult to put into words exactly how you balance and ride a bicycle.Thus the key difference is that declarative memory is ‘knowing that’ (verbally expressible facts) while procedural memory is ‘knowing how’ (skills that are hard to verbalise).
5. Why does forgetting take place?
ANSWERForgetting is the loss of stored information over a period of time. Ebbinghaus showed that after learning there is a sharp initial drop in memory, after which the decline is very gradual. Psychologists explain forgetting mainly through three theories:(i) Trace decay (disuse theory): learning creates memory traces (physical changes) in the nervous system; when these traces are not used for a long time, they fade away and become unavailable. (This theory was found inadequate, since people who sleep after learning — and so cannot ‘use’ the trace — actually forget less than those who stay awake.)(ii) Interference: forgetting occurs because different sets of associations stored in memory compete with one another at the time of retrieval. Interference may be proactive (earlier learning interferes with the recall of later learning) or retroactive (later learning interferes with the recall of earlier learning).(iii) Retrieval failure: forgetting can also occur when, at the time of recall, the retrieval cues are absent or inappropriate. Information that is stored may become inaccessible without the right cues, even though it has not been lost from the store.
6. How is retrieval related forgetting different from forgetting due to interference?
ANSWERForgetting due to interference assumes that learning forms associations between items, and these associations remain in the memory store. Forgetting happens because, at the time of retrieval, the various sets of associations compete with one another. This may be proactive (past learning hampers recall of new learning) or retroactive (new learning hampers recall of old learning). Here the cause of forgetting lies in the mutual conflict between stored memories.Retrieval-related forgetting, advanced by Tulving and associates, holds that information may become inaccessible not because traces have decayed or because associations compete, but because the retrieval cues are absent or inappropriate at the time of recall. Retrieval cues are aids that help recover stored information; when category names or the physical context of learning are provided as cues, recall improves dramatically.The key difference: in interference theory the stored memories actively conflict and block one another, whereas in retrieval-failure the memory is intact but cannot be reached because the proper cues to access it are missing.
7. Define mnemonics? Suggest a plan to improve your own memory.
ANSWERMnemonics (pronounced ni-mo-nicks) are strategies or techniques used for improving memory. Some mnemonics make use of mental images, while others emphasise the self-induced organisation of the material to be learned.Mnemonics using images: (a) the keyword method — choosing a familiar word that sounds like the new (e.g. foreign) word and forming an interacting image of the two (e.g. imagining a duck in a ‘pot’ to remember the Spanish word ‘Pato’); (b) the method of loci — placing the items to be remembered as images at familiar physical locations in a sequence, then taking a mental walk to recall them in order.Mnemonics using organisation: (a) chunking — combining smaller units into larger meaningful chunks; (b) the first-letter technique — forming a word or sentence from the first letters of items, e.g. VIBGYOR for the colours of the rainbow.A plan to improve my own memory: (i) engage in deep-level (semantic) processing by asking questions about the meaning of what I study and relating it to what I already know; (ii) minimise interference by not studying very similar subjects one after another and by taking intermittent rest periods (distributed practice); (iii) give myself enough retrieval cues by linking parts of the material to memorable cues; and (iv) use the PQRST method (Preview, Question, Read, Self-recitation, Test). I would also attend to health, interest and motivation, since no single technique improves memory overnight.
Extra Practice Questions
Short Answer Type Questions
Q1. What is sensory memory, and name its two well-known types.
ANSWERSensory memory is the first memory store that registers incoming information from the senses as an exact replica of the stimulus. It has a very large capacity but an extremely short duration of less than one second. Its two well-known types are the iconic (visual) register and the echoic (auditory) register.
Q2. What is chunking, and how does it help memory?
ANSWERChunking is a control process in which several smaller units are combined into larger meaningful units called chunks. It expands the limited capacity of the short-term memory (otherwise 7±2). For example, the long string 194719492004 can be chunked into 1947, 1949 and 2004, making it far easier to remember.
Q3. State the contribution of Hermann Ebbinghaus to the study of memory.
ANSWERHermann Ebbinghaus carried out the first systematic study of memory and forgetting (1885), experimenting on himself using lists of nonsense syllables (CVC trigrams such as NOK). His ‘curve of forgetting’ showed that forgetting is fastest in the first nine hours, especially the first hour, after which it slows greatly — we do not forget at an even pace.
Q4. Differentiate between episodic and semantic memory.
ANSWERBoth are types of declarative memory. Episodic memory holds the biographical, dated and often emotional events of our personal lives (e.g. how we felt on standing first in class). Semantic memory holds general knowledge, concepts and rules of logic (e.g. that 2+6=8 or the meaning of ‘non-violence’); it is not dated and is affect-neutral.
Q5. What are the three levels of processing proposed by Craik and Lockhart?
ANSWERThe three levels are the structural (physical features, the shallowest), the phonetic (the sounds attached to letters, an intermediate level), and the semantic (the meaning of the information, the deepest level). The deeper the level of processing, the better and longer the information is retained.
Long Answer Type Questions
Q1. Describe the Stage Model of memory proposed by Atkinson and Shiffrin.
ANSWERThe Stage Model, proposed by Atkinson and Shiffrin in 1968, drew on the analogy of the computer and is the first model of memory. It holds that there are three memory systems through which information is processed. The sensory memory registers information from the senses with large capacity but a duration of less than a second; unattended impressions fade away. Information that receives selective attention enters the short-term memory, which holds about 7±2 items for around 30 seconds, encoded acoustically; maintenance rehearsal keeps it alive and chunking expands its capacity. Through elaborative rehearsal, information passes into the long-term memory, a permanent store of unlimited capacity in which encoding is semantic. The flow between stores is governed by control processes — selective attention, maintenance rehearsal, chunking and elaborative rehearsal. While many experiments support the distinctiveness of STM and LTM (such as the case of patient KF), later evidence questioned a rigid separation, since information can be encoded semantically in STM and acoustically in LTM.
Q2. Explain the interference theory of forgetting with its two types.
ANSWERThe interference theory is one of the most influential explanations of forgetting. It assumes that learning and memorising involve forming associations between items, and that these associations remain in the memory store, each resting independently. Forgetting, however, comes about at the time of retrieval, when different sets of associations compete with one another for recall. There are two kinds of interference. In proactive interference (forward moving), what was learned earlier interferes with the recall of later learning — for example, knowing English may make it harder to learn French. In retroactive interference (backward moving), later learning interferes with the recall of earlier learning — for example, after memorising French equivalents, one may fail to recall the English words learned before. The classic demonstration uses two lists (A and B): for retroactive interference, participants learn A, then B, then recall A; for proactive interference, they learn A, then B, then recall B. The theory shows that forgetting is often caused by conflict among stored memories rather than by the simple decay of traces.
Q3. Discuss the strategies suggested by psychologists for enhancing memory.
ANSWERPsychologists suggest both mnemonic techniques and broader, comprehensive strategies for improving memory. Mnemonics using images include the keyword method, in which a familiar word that sounds like the target word is chosen and the two are imagined interacting (e.g. a duck in a ‘pot’ for the Spanish ‘Pato’), and the method of loci, in which items are placed as images at familiar locations and recalled by a mental walk. Mnemonics using organisation include chunking (combining small units into larger meaningful chunks) and the first-letter technique (e.g. VIBGYOR for the rainbow’s colours). Because mnemonics can be too simplistic, a more comprehensive approach is also advised: engage in deep-level processing by attending to meaning rather than surface features; minimise interference by avoiding the learning of similar subjects in sequence and by distributing practice with rest periods; and give yourself enough retrieval cues by linking material to memorable cues. The PQRST method (Preview, Question, Read, Self-recitation, Test) helps students remember more. Finally, factors such as health, interest, motivation and familiarity must also be attended to, as no single method brings overnight improvement.
MCQs & Assertion–Reason
1. The process by which information is recorded and registered for the first time is called:
For each Assertion–Reason question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.
A-R 1. Assertion: Sensory memory has a very short duration.
Reason: The sensory register holds an exact replica of the stimulus that decays automatically in less than a second.
A-R 2. Assertion: Maintenance rehearsal alone transfers information into long-term memory.
Reason: Maintenance rehearsal retains information through simple repetition and the material is lost when repetition stops.
A-R 3. Assertion: Semantic memory is generally affect-neutral and not dated.
Reason: Semantic memory stores facts, concepts and general knowledge rather than personal life events.
A-R 4. Assertion: Retrieval failure can cause forgetting even when information is still stored.
Reason: Stored information may become inaccessible when retrieval cues are absent or inappropriate at the time of recall.
A-R 5. Assertion: Deeper processing of information leads to better retention.
Reason: Encoding information in terms of its meaning resists forgetting more than attending to its structural or phonetic features.
Answer key: 1-(A), 2-(D), 3-(A), 4-(A), 5-(A).
Exam Tips & Common Mistakes
How to score full marks in this chapter
Memorise the three stages (encoding, storage, retrieval) and the three stores with their capacity and duration (sensory < 1 sec; STM 7±2 items, ~30 sec; LTM unlimited, lifetime). For ‘differentiate’ questions (maintenance vs elaborative rehearsal; declarative vs procedural; episodic vs semantic; proactive vs retroactive interference) use a clear two-sided structure with one example each. Always attach the right researcher to the right idea — Atkinson & Shiffrin (Stage Model), Craik & Lockhart (levels of processing), Baddeley (working memory), Tulving (retrieval cues, episodic/semantic), Ebbinghaus (forgetting curve). Use textbook examples (the 194719492004 chunking example, VIBGYOR, the ‘Pato’/‘pot’ keyword, patient KF) to show depth.
Common mistakes to avoid
Saying STM stores information “permanently” — its duration is only about 30 seconds.
Confusing maintenance rehearsal (mere repetition in STM) with elaborative rehearsal (meaningful association into LTM).
Mixing up proactive (old interferes with new) and retroactive (new interferes with old) interference.
Confusing declarative (facts) with procedural (skills) memory, or episodic (personal events) with semantic (general knowledge) memory.
Treating trace decay as a fully accepted theory — it was found inadequate (sleep vs waking results).
Forgetting that retrieval-failure means the memory is intact but inaccessible due to missing cues.
Frequently Asked Questions
What is Chapter 6 of Class 11 Psychology about?
Chapter 6, Human Memory, explains memory as a process of encoding, storage and retrieval; the Stage Model with sensory, short-term and long-term memory; the levels of processing view; types of long-term memory (declarative/procedural and episodic/semantic); the causes of forgetting (trace decay, interference and retrieval failure); and mnemonic strategies for enhancing memory.
What is the difference between short-term and long-term memory?
Short-term memory holds a small amount of attended information (about 7±2 items) for roughly 30 seconds, encoded acoustically, and is fragile. Long-term memory is a permanent store of unlimited capacity in which information is encoded semantically and can last a lifetime; material moves from STM to LTM through elaborative rehearsal.
What is the exercise heading for Chapter 6 of Class 11 Psychology?
The end-of-chapter exercise in NCERT Class 11 Psychology Chapter 6 is headed Review Questions and contains 7 numbered questions, all answered step by step on this page.
