Human Memory

Written and reviewed by Subhra Gupta, Humanities faculty at UniDrill (M.A. Sociology, University of Delhi · 7 years teaching Humanities). Based on NCERT Psychology Class XI (Introduction to Psychology), Chapter 6.

Why can you sing a song from Class 2 but not remember a name you heard a minute ago?

You have felt both. The name of the person you were just introduced to is gone, yet the lines of a poem you learnt as a child roll out without effort. Memory is not one box that keeps everything. It is a system with stages, stores and failure points, and this chapter shows you where each failure happens. That is also exactly how CUET frames its questions: a short everyday situation, then "which concept is this?"

Memory has three stages, and it can fail at each

Memory is the retaining and recalling of information over a period of time. It works through three connected stages, and everything you learn must pass through all of them in this order.

Pause and predict: a student says "I studied the whole chapter but my mind went blank in the exam." Which stage has probably failed?

Check your answer: most likely retrieval. If she could recall the material the next day, it was encoded and stored. The cues that would bring it back were missing under exam pressure. Memory failure can happen at any stage, so always ask "was it never learnt, never kept, or not reachable?"

The Stage Model: memory as a computer

In 1968 Atkinson and Shiffrin compared the mind to a computer, which has a temporary memory (RAM) and a permanent one (hard disk). Their Stage Model says information passes through three stores in a fixed order.

Sensory memory has separate registers for each sense. The iconic register holds visual information and the echoic register holds sounds. The trail left by a sparkler is iconic. The reverberation after a bell has stopped is echoic.

Control processes decide what travels from one store to the next and what stays.

Chunking at work. The string 194719492004 is twelve digits, too long for STM. Split it into 1947, 1949 and 2004 and it becomes three chunks that most students already know. The same trick turns a 10 digit mobile number into 98765 43210.

Maintenance versus elaborative. Repeating "humanity, humanity, humanity" only keeps the word alive for a moment. Connecting it to compassion, truth and benevolence, which you already understand, is what sends it into LTM. The more associations you build, the more permanent the memory.

Why LTM forgetting is really retrieval failure. According to the model, once information enters LTM it is never lost, because it is stored by meaning. What feels like forgetting is a failure to get at it. This idea comes back in the forgetting section.

Beyond the textbook. For the exam: STM capacity is 7 ± 2 items. In reality: the number 7 comes from early work and later studies suggest that when items are unrelated and rehearsal is blocked, people hold closer to four chunks. Chunking is what makes bigger spans possible. Why it matters: if a question asks for the textbook figure, write 7 ± 2, and use the idea that capacity is limited and chunking stretches it.

Working Memory: STM as a workbench

Baddeley (1986) argued that STM is not a passive shelf but a workbench where information is held and worked on, as when you do mental arithmetic. He split it into three parts.

Two models, one argument: Stage Model versus Levels of Processing

The Stage Model has a weak spot. It says information must travel through STM to reach LTM. Shallice and Warrington (1970) described a patient known as KF who damaged a part of the left side of his cerebral hemisphere in an accident. His LTM stayed intact while his STM was seriously affected. If STM is a compulsory gateway, how could his LTM work normally?

Evidence like this, and later findings that STM can also encode by meaning and LTM by sound, led Craik and Lockhart (1972) to a different view. They said memory depends less on which store information sits in and more on how deeply it was processed when it came in.

The practical lesson is that rote repetition is shallow processing. Asking yourself "what does this mean and how does it connect to what I know?" is deep processing.

Two views. For the exam: the Stage Model describes memory as three separate stores, and the Levels of Processing view is a second model that explains retention through depth of encoding. Another reading: many memory researchers see the two as answering different questions. The Stage Model describes structure, while Levels of Processing describes the quality of encoding, and later versions of both models have borrowed ideas from each other.

Types of long term memory

LTM is not a single store. It is divided in two overlapping ways.

You can explain how cricket is played, but try describing exactly how you balance on a bicycle. That gap is the declarative and procedural difference.

Tulving then divided declarative memory into two parts.

Ask yourself when you learnt that Bengaluru is the capital of Karnataka. You cannot say, and that is exactly why it is semantic.

Special kinds of memory

Beyond the textbook. For the exam: flashbulb memories are very detailed, like a frozen photograph. In reality: studies that tracked people after major public events found that their confidence in these memories stayed high while the details they gave changed over time. Vividness is not the same as accuracy. Why it matters: if an option says "flashbulb memories are always accurate", reject it.

How psychologists measure each memory. The method has to match the type of memory.

Why we forget

The first systematic study of forgetting was by Hermann Ebbinghaus (1885). He memorised lists of nonsense syllables of the consonant, vowel, consonant kind (such as NOK or SEP), then measured how many trials he needed to relearn them after different gaps. Meaningless syllables were used so that earlier associations would not help. His curve of forgetting drops sharply in the first nine hours, especially the first hour, then flattens. Not much more is lost even after many days.

Why this matters to you: revise within the first hours after a class, not a week later.

Three theories explain why forgetting happens.

Proactive versus retroactive interference. Interference is the most-tested idea here. Look at which direction the damage moves.

A quick way to remember it: proactive, the problem comes from the past, and retroactive, the new learning pushes back retrospectively.

Pause and predict: a person uses the same locker code for four years. When it is changed, she keeps trying the old code. Is this proactive or retroactive interference?

Check your answer: proactive. The earlier learning (old code) interferes with the recall of the new one. If instead she had forgotten the old code after learning the new one, it would be retroactive.

Retrieval cues. Retrieval cues are aids that help us recover stored information, such as category names or the physical setting in which you learnt something. Without them, information may exist yet be unreachable. This is why recognition is easier than recall: the options act as cues.

Two views. For the exam: Freud proposed that painful experiences are repressed into the unconscious and kept out of awareness, and that extreme repression can produce a fugue state in which a person assumes a new identity, name and address. Another reading: many memory researchers question how often repression actually occurs. They argue that deeply distressing events are often remembered all too well, and that the scientific status of repressed memories is still debated.

Beyond the textbook. For the exam: forgetting is explained as decay, interference or retrieval failure. In reality: Bartlett's classic studies in which people retold a story again and again showed that memory is also reconstructive. Retellings became shorter and more conventional and details changed to fit the person's own expectations. Why it matters: it explains why two people honestly remember the same event differently, and why serial reproduction is among the chapter's key terms.

Improving memory

Mnemonics are strategies to improve memory. Some use images, others use organisation.

Mnemonics alone are too simple for the complexity of real learning. The wider advice is to use what you now know about memory.

Who said what

Exam traps

60-second revision

Where this chapter connects

• Earlier chapter: Sensory, Attentional and Perceptual Processes explains selective attention, the first control process that decides what enters STM.
• Earlier chapter: Learning covers how experience changes behaviour, which memory then retains.
• Next chapter: Thinking shows memory at work in problem solving, reasoning and decision making.
• Class XII link: Psychological Disorders returns to dissociative conditions such as the fugue state met here in the repression discussion.