[Models of executive control and functions. II].
BACKGROUND
Current models of the executive functions enable us to state that this construct embraces a large number of processes and sub processes that are in turn linked to different regions of the brain, and more specifically to the prefrontal cortex. Recent data suggest that different areas of the prefrontal cortex may be involved in a number of aspects related to executive functioning.


METHODS
The aim of this article is to review the most important models of executive functioning in order to shed light on this controversial construct. The models put forward to date approach the same reality from a number of different perspectives, although in some cases they neglect certain parts of that reality. In this second part of our paper, we review the dynamic filter theory, the differential axes model, the theory of cognitive complexity and control, the theory of hierarchical representation, the attentional control model, the supervisory attentional system and the input hypothesis.


CONCLUSIONS
From the results obtained in the studies that were reviewed we can state that it is possible to divide the 'executive functions' construct into sub processes in order to make understanding, assessment and intervention easier. Each of these sub processes seems to be related to a specific area in the prefrontal cortex, although a particular region can be involved in different aspects of executive functioning at different moments in time.
Tirapu-Ustárroz
J
J
Unidad de Rehabilitación Neurológica, Clínica Ubarmin, E-31486 Elcano, Navarra, España. jtirapuu@cfnavarra.es
García-Molina
A
A
Luna-Lario
P
P
Roig-Rovira
T
T
Pelegrín-Valero
C
C
D001288:Attention / Q000502:physiology; D006801:Humans; D008606:Mental Processes / Q000502:physiology*; D008954:Models, Biological; D017397:Prefrontal Cortex / Q000502:physiology*