Theory

Working memory is a cognitive system that enables us to temporarily hold, process, and manipulate information while performing complex tasks. It acts as a mental workspace, supporting essential functions like problem-solving, decision-making, reasoning, and language comprehension. Working memory has a limited capacity. The famous theory by Miller (1956) suggests that the typical capacity of working memory is 7 items, plus or minus 2. This means that most people can hold between 5 and 9 pieces of information in working memory at a given time.

Working memory is made up of three key components:

• Central Executive:
  This is the control center of working memory. It directs attention, manages the flow of information, and coordinates cognitive activities. The central executive also allocates mental resources to focus on tasks and strategies, making it crucial for multitasking and decision-making.

• Phonological Loop:
  The phonological loop deals with auditory and verbal information, such as spoken words or numbers. It allows us to rehearse and maintain information through mental repetition, like remembering a phone number by repeating it to ourselves.

• Visuospatial Sketchpad:
  This component processes visual and spatial information, such as mentally visualizing an object or remembering the layout of a room. It helps us track positions, recognize shapes, and mentally "see" information.

The N-Back Task

The N-Back task is a widely used method to assess working memory capacity, specifically targeting the central executive.

In this task, participants are shown a sequence of stimuli—like letters, numbers, or shapes—one at a time. The goal is to identify when the current stimulus matches the one presented N steps earlier.

For example, in a 2-Back task, participants respond when the current stimulus matches the one presented two positions earlier.

• Example Sequence: A → B → A → C → A
• Task: Identify that the current "A" matches the "A" shown two steps back.

As the value of N increases (e.g., 3-Back, 4-Back), the task becomes more challenging. Participants must hold and update a longer sequence of items in working memory, which places greater demands on the central executive.

Purpose and Importance

The N-Back task serves two major purposes:

• Measuring Working Memory:
  It evaluates accuracy (how well participants identify matches) and reaction time (how quickly they respond). These metrics provide insights into the limits and capabilities of working memory.

• Training Working Memory:
  Regular practice with the N-Back task can improve working memory capacity and enhance fluid intelligence, which is the ability to solve new, unfamiliar problems.
  Studies suggest that training with this task helps the brain become better at updating and managing information efficiently.

Summary

The N-Back task is a powerful tool for understanding the strengths and limitations of working memory. It challenges participants to actively hold, process, and update information, providing valuable insights into cognitive performance and training.