Baddeley and Hitch (1974) replaced Atkinson and Shiffrin's unitary short-term store with a multicomponent working memory model. What was the primary motivation for this revision?
A: Short-term memory was found to be unlimited in capacity, making a single-store model unnecessary
B: Dual-task studies and neuropsychological cases showed that STM is not a single unitary system — tasks using different types of information can proceed simultaneously without mutual interference
C: Brain imaging revealed that short-term memory is localised in a single brain region, which contradicted the multi-store model
D: The multi-store model had already been discredited by Peterson and Peterson's (1959) research
Correct: Dual-task studies and neuropsychological cases showed that STM is not a single unitary system — tasks using different types of information can proceed simultaneously without mutual interference
Baddeley and Hitch conducted a series of dual-task experiments: participants performed a reasoning task while simultaneously holding digit strings in memory. If STM were a single gateway to cognition, holding several digits should have severely disrupted reasoning. In fact, disruption was modest — suggesting that different subsystems handle verbal storage and reasoning in parallel. Combined with neuropsychological evidence from patients like K.F. (who had impaired digit span but intact long-term learning), this motivated replacing the single STM store with a multicomponent working memory system.
What is the function of the central executive in Baddeley's working memory model?
A: It stores phonological (sound-based) information for up to 2 seconds
B: It is a passive buffer that integrates information from long-term memory with sensory input
C: It is the attentional control system that coordinates the slave systems, switches and divides attention, and links working memory to long-term memory
D: It maintains visuospatial representations during spatial navigation
Correct: It is the attentional control system that coordinates the slave systems, switches and divides attention, and links working memory to long-term memory
The central executive is the most important but least understood component of the model. It functions as an attentional controller — allocating resources between the phonological loop and visuospatial sketchpad, switching attention between tasks, and connecting working memory processes to long-term memory. It is involved in planning, reasoning, and inhibiting irrelevant information. Baddeley acknowledged that the central executive is underspecified; Miyake et al. (2000) later proposed that it consists of three separable functions: inhibition, updating, and shifting.
The phonological loop consists of two sub-components. What are they and what are their respective roles?
A: The phonological store (passive acoustic trace lasting ~2 seconds) and the articulatory rehearsal process (inner voice that refreshes traces)
B: The visual buffer (stores visual images) and the spatial planner (plans movements)
C: The semantic store (holds word meanings) and the phonological rehearsal loop (refreshes sounds)
D: The episodic buffer (integrates information) and the executive controller (directs attention)
Correct: The phonological store (passive acoustic trace lasting ~2 seconds) and the articulatory rehearsal process (inner voice that refreshes traces)
The phonological loop has two components: (1) the phonological store — a passive auditory memory that holds sound-based information for about 1.5–2 seconds before it decays; and (2) the articulatory rehearsal process — the "inner voice" that refreshes decaying traces by sub-vocal rehearsal, much like muttering items to yourself. Evidence includes the phonological similarity effect (acoustically similar items are harder to recall), the word length effect (shorter words are recalled better than longer ones — because rehearsal can cycle through more short words per unit time), and the irrelevant speech effect (background speech disrupts phonological loop tasks even when it is semantically irrelevant).
The word length effect is a key piece of evidence for the phonological loop. What does it demonstrate?
A: Long words have more semantic meaning and are therefore better encoded into long-term memory
B: People can recall as many words as they can rehearse in approximately 1.5–2 seconds, regardless of the number of syllables
C: The phonological store holds exactly 7 words of any length
D: Word length affects encoding into the visuospatial sketchpad, not the phonological loop
Correct: People can recall as many words as they can rehearse in approximately 1.5–2 seconds, regardless of the number of syllables
The word length effect shows that people recall more short words than long words from immediate verbal memory (e.g., "cat, dog, hat" vs. "opportunity, university, refrigerator"). Baddeley et al. (1975) found that memory span is approximately equal to the number of words that can be articulated in about 1.5–2 seconds — regardless of absolute word count. This supports the articulatory rehearsal process: the inner voice refreshes traces by cycling through them, so fewer long words fit within one rehearsal cycle and more of them decay. Articulatory suppression (saying "the the the" aloud) abolishes the word length effect, confirming it depends on the rehearsal mechanism.
The visuospatial sketchpad is the component of working memory dedicated to visual and spatial information. Which finding best demonstrates its independence from the phonological loop?
A: Performing a spatial tracking task (following a moving dot) interferes with a simultaneous verbal digit span task, suggesting the two systems share resources
B: A spatial tracking task interferes specifically with other spatial tasks but not with verbal memory tasks, demonstrating a separate visual/spatial resource
C: Visual imagery tasks are stored in the phonological loop because mental images are typically described using words
D: The visuospatial sketchpad and phonological loop are the same system — they differ only in the modality of input
Correct: A spatial tracking task interferes specifically with other spatial tasks but not with verbal memory tasks, demonstrating a separate visual/spatial resource
Dual-task studies by Baddeley and Lieberman (1980) and others demonstrated a clear double dissociation: a spatial tracking task (tapping a moving target while blindfolded) interfered with visualisation tasks (like Brookes' matrix task) but not with verbal digit span; conversely, articulatory suppression disrupted digit span but not visualisation. This dissociation confirms that verbal and visuospatial working memory draw on separate, limited resources. The sketchpad supports mental imagery, spatial navigation, and tasks like reading maps or mentally rotating objects.
Baddeley (2000) added a fourth component to the original three-part model. What is the episodic buffer and what does it do?
A: A fourth slave system that stores emotional memories for up to one hour
B: A limited-capacity, multimodal store that integrates information from the phonological loop, visuospatial sketchpad, and long-term memory into coherent episodic representations
C: An upgraded version of the phonological loop that can handle both auditory and visual input
D: A system dedicated to storing autobiographical memories from childhood
Correct: A limited-capacity, multimodal store that integrates information from the phonological loop, visuospatial sketchpad, and long-term memory into coherent episodic representations
The episodic buffer was added to address a gap in the 1974 model: how are verbal and visual information integrated with each other and with long-term memory? The episodic buffer is a limited-capacity store (roughly 4 chunks) that holds integrated, multimodal representations — "episodes" binding information across space, time, and modality. For example, remembering a sentence requires integrating phonological sequences with semantic knowledge — a task that neither the phonological loop nor the visuospatial sketchpad alone can accomplish. The buffer is thought to be controlled by the central executive and is accessible to conscious awareness.
Individual differences in working memory capacity are strongly correlated with which outcomes?
A: Reaction time in simple motor tasks but not with higher cognitive abilities
B: Fluid intelligence, reading comprehension, and mathematical ability; and are associated with learning difficulties such as dyslexia and ADHD
C: Only long-term memory retrieval; there is no relation between working memory and real-world cognitive performance
D: Crystallised intelligence (acquired knowledge) but not fluid intelligence (novel reasoning)
Correct: Fluid intelligence, reading comprehension, and mathematical ability; and are associated with learning difficulties such as dyslexia and ADHD
Working memory capacity is one of the strongest predictors of individual differences in cognitive ability. Daneman and Carpenter (1980) demonstrated that working memory span (measured by tasks that combine storage and processing) predicts reading comprehension much better than simple digit span. Subsequent research has linked working memory capacity to fluid intelligence, mathematical reasoning, and language comprehension. Children with dyslexia, dyscalculia, and ADHD consistently show reduced working memory — particularly in the phonological loop. These associations have made working memory assessment a clinically useful tool for identifying learning difficulties.
Which of the following is a well-supported criticism of Baddeley's working memory model?
A: The model has no empirical support; it was proposed as a purely theoretical framework
B: The central executive is inadequately specified — it is described by what it does rather than what it is, making it difficult to test empirically
C: The model cannot account for verbal memory; all evidence comes from visuospatial tasks
D: The model predicts that people cannot perform two cognitive tasks simultaneously, which is clearly false
Correct: The central executive is inadequately specified — it is described by what it does rather than what it is, making it difficult to test empirically
The working memory model's most acknowledged weakness is the underspecification of the central executive. Baddeley himself described it as a "ragbag" — a catch-all for attentional processes that could not be assigned to the slave systems. It lacks detailed structural specification and therefore generates fewer testable predictions than the slave systems. Attempts to resolve this include Norman and Shallice's Supervisory Attentional System (SAS) and Miyake et al.'s (2000) three-factor model of executive functions (inhibition, updating, shifting). Nevertheless, the overall model has proven extremely fruitful and is the dominant framework for working memory research.
The Working Memory Model
Baddeley and Hitch (1974) replaced Atkinson and Shiffrin's unitary short-term store with a multicomponent working memory model. What was the primary motivation for this revision?
About this quiz
Baddeley and Hitch (1974) replaced the unitary concept of "short-term memory" with a multicomponent working memory system — an active workspace for holding and manipulating information during cognition. The model was extended in 2000 with the addition of the episodic buffer.
This quiz covers each component of the model, the evidence from dual-task studies and neuropsychological cases, and the model's strengths and limitations. Key sources include Baddeley & Hitch (1974), Baddeley (2000), and supporting experimental research.