Models of Executive Functions

Miyake, Baddeley, Norman & Shallice

1. Overview

Executive functions are a set of higher‑order control processes that regulate goal‑directed behavior. Three foundational frameworks dominate contemporary cognitive science: Miyake’s unity/diversity model, Baddeley’s working‑memory model, and Norman & Shallice’s supervisory system.

2. Miyake et al. (2000): Unity and Diversity

A data‑driven model identifying three separable but correlated executive components:

• Inhibition — suppressing dominant or automatic responses.
• Shifting — switching between mental sets or tasks.
• Updating — refreshing and replacing information in working memory.

The model shows that executive functions share a common core yet maintain distinct contributions to complex cognition.

3. Baddeley (1986–2012): Working‑Memory Architecture

Baddeley’s framework positions executive control as the central executive, supported by specialized storage systems:

• phonological loop — verbal information
• visuospatial sketchpad — spatial/visual information
• episodic buffer — integrated multimodal representations

The central executive handles attentional allocation, task coordination, and control of subordinate systems.

4. Norman & Shallice (1986): Supervisory Attentional System

A functional model describing how controlled processing overrides automatic routines:

• contention scheduling — manages routine, well‑learned actions
• supervisory attentional system (SAS) — intervenes when novel, conflicting, or high‑risk situations require deliberate control

This framework explains error correction, planning, and behavior under non‑routine conditions.

5. Distinctions Across Models

• Miyake — component‑based, empirical, factor‑analytic.
• Baddeley — structural, memory‑centric, architecture of control.
• Norman & Shallice — functional, mechanism‑oriented, focused on automatic vs controlled action.

Together, they form a multi‑level understanding of executive control: components → architecture → functional regulation.

6. Example

A person driving in heavy traffic must inhibit an impulsive lane change (Miyake: inhibition), update route information (Miyake: updating), coordinate visual and verbal inputs (Baddeley: central executive + buffers), and override habitual responses when an unexpected hazard appears (Norman & Shallice: SAS).