The working memory, also known as “operational” , is a cognitive system that retains information in the short term and manipulates it, thus allowing the execution of complex psychological behaviours and processes such as decision making or mathematical calculation.

The original theory that described working memory was the work of psychologists Baddeley and Hitch. In this article we will analyze the components of working memory according to this model and the functions that correspond to each of them.

Working and short-term memory

During the 50s and 60s of the last century, different theories about memory emerged within the framework of the cognitivist paradigm. First there was talk of sensory memory, which included iconic or visual and echoic or auditory memory, and later the distinction between short-term and long-term memory predominated.

The concept of short-term memory has been progressively replaced by that of operational or working memory. This change is due to the fact that, since the contributions of Alan Baddeley and Graham Hitch in the 1970s, this type of report is considered not only to be a passive store of information but also to operate on it.

According to Baddeley and Hitch the working memory is composed of a set of components that interact with each other. These systems work with “items” of verbal , visual or other types of information ; an item is understood as any unit of information with meaning for the person.

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The Baddeley and Hitch multi-component model

The classical model of working memory was composed of three components: the central executive, which manages the use of cognitive and attentional resources, and two subordinate systems that process unimodal information, the phonological loop and the articulatory loop.

Later, Baddeley added a fourth component, the episodic buffer.

1. Central Executive

Baddeley and Hitch described the existence of an attention control system that they called “central executive”. The main function of this component is to assign the attentional resources to the tasks we are performing at a given time, so that the rest of the mnemonic systems are directed by the central executive.

This system also stores information but its capacity is limited; when demand exceeds the resources of the central executive, the latter resorts to the phonological loop and the visuospatial agenda , which Baddeley and Hitch described as “slave subsystems”.

2. Phonological loop or articulatory loop

The phonological loop is a system that retains verbal information in acoustic format temporarily . Depending on the model, the articulatory loop can passively hold a maximum of 3 items for 2 seconds; if we perform a “subvocal review” operation by repeating the information through internal speech, the capacity increases to 7 items.

If we focus on the passive side of the phonological loop, this component is close to the concept of echoic memory , described by George Sperling and Ulric Neisser as a brief mental representation of acoustic information.

3. Visospatial Agenda

Baddeley and Hitch described a second slave subsystem that works with images: the visospatial agenda. Its characteristics are similar to those of the phonological loop, differing basically in that it handles visual rather than sound information.

The visuospatial agenda has not been investigated as much as the articulatory link and its characteristics have not been fully confirmed. Research suggests that the brain could process visual information (perception of details, colour, etc.) and spatial information, including the location and movement of stimuli, separately.

4. Episodic buffer

The episodic buffer is the fourth and final component of the classic working memory model, which was added by Baddeley in 1991 to its original formulation. From a theoretical point of view it is associated with the executive functions of the frontal lobe of the brain.

According to Baddeley, it is a temporary warehouse with restricted capacity, such as the articulatory link and the visospatial agenda. However, works with multimodal information instead of just words or images. Its other fundamental characteristic is that it allows the exchange of information between long-term memory and operational memory.

TM functions: control operations

As we have said, the main difference between the concept of short-term memory and that of working memory is that the former was understood as a passive store, while active functions related to the handling of available information are also attributed to working memory .

Let’s see what these control operations consist of.

1. Repetition

The repetition of the information stored in the operating memory allows it to be retained for longer, which, in turn, gives time for other control operations to take place . When this occurs, the probability of short-term memory being transferred to long-term memory increases.

2. Recoding, grouping or “chunking”

Recoding consists of creating complex segments of information (“chunks”) from simpler items. In addition to working memory, this operation involves long-term memory , since the rules and strategies that guide recoding are stored in it.

3. Execution of complex cognitive tasks

Working memory deals with tasks such as listening and reading comprehension , problem solving, e.g. mathematics, and decision making . These processes are related to the higher cognitive functions and depend on the interaction between the stimulation received and the information stored in the long-term memory.

Is it related to intelligence?

Working memory is considered to be very closely related to intelligence, in the sense that greater capacity in this type of memory is reflected in better IQ scores. However, little is known yet about how the two constructs fit together.