Executive functions are cognitive functions needed to deal
with new and unfamiliar tasks. Examples
of executive functions would be identifying a goal or a problem, planning how
to reach that goal or how to solve that problem, choosing an action plan among
alternatives, initiating the plan, monitoring the plan's execution, responding
flexibly when problems arise, and inhibiting automatic responses that are not conducive to reaching the solution.
In Adele Diamond's conceptualization (4), executive functions
are composed of three components:
Inhibition: behavioral inhibition (self control and the
ability to resist temptation) and cognitive inhibition (controlling internal
and external distractions and inhibiting automatic responses).
Working memory – which enables
planning and monitoring progress towards goal
attainment.
Flexible thinking – which enables
us to think about new solutions and to change strategy if the chosen one
doesn't lead to the preferred
results.
.
Where do executive functions fit within
CHC terminology?
When we speak about "executive
functions" and about "CHC abilities" we use two different languages. The concept "Executive functions" belongs to neuropsychological theories. CHC abilities are concepts belonging to
psychometric theory. Thus, asking "Where
do executive functions fit within CHC terminology?" is like asking "How
do you say "caucus" in French"?
There probably is no French concept which exactly parallels the meaning
of "caucus" in American English.
Nevertheless, executive functions can be placed between Fluid Ability
and Short Term Memory. The relations
between them are presented in the slide below:
The relation between Executive
Functions and Fluid Ability:
Flanagan and her colleagues (1) define Fluid Ability as
"mental operations that an individual may use when faced with a relatively
novel task that cannot be performed automatically". These thinking processes include identifying
and constructing concepts and relations, deriving conclusions, understanding
consequences, abstract thinking, problem solving, reorganizing or restructuring
information, inductive and deductive reasoning, classifying, creating
hypotheses and quantitative reasoning.
According to this conceptualization,
the common element of Fluid Ability and Executive Functions is the Flexibility
in reasoning.
McGrew, in the CHC version 2 definitions, defines Fluid Ability like
this: "The deliberate but flexible control of attention to solve novel
“on the spot” problems that cannot be performed by relying exclusively on
previously learned habits, schemas, and scripts".
This conceptualization emphasizes
the control of attention, and through it, the inhibition component, as a common
component of Fluid Ability and Executive Functions, along with the Flexibility
component.
Thus, this conceptualization brings Fluid Ability and Executive
Functions closer together. According to
this conceptualization, in order to solve new problems successfully, we must
recruit attentional resources and inhibit automatic and well practiced
responses.
Salthouse writes: "Contextual analyses have
… revealed very strong relations of fluid cognitive ability (Gf) to constructs
hypothesized to represent executive functioning
and to assorted variables postulated to represent specific aspects of
executive functioning. These patterns
suggest that Gf may reflect nearly the same dimension of individual differences
as executive functioning".
What about the relation between
Executive Functions and Short Term Memory?
Short Term Memory is "the ability to apprehend and hold
information in immediate awareness and then use it within a few seconds"
(1). The broad ability Short Term Memory
contains two narrow abilities: Memory
Span (the ability to attend to and immediately recall temporally ordered
elements in the correct order after a single presentation) and Working Memory
(the ability to temporarily store and perform a set of cognitive operations on
information that requires divided attention and the management of the limited
capacity of short term memory".
Thus, the common element of
Executive functions and Short Term Memory is the Working Memory component (by
Adele Diamond's conceptualization, according to which one of the components of
Executive Functions is Working Memory).
"Executive function deficits may be most noticeable in the
capacity of the individual to allocate and sustain attentional resources…Attentional
capacity, and to some extent divided attention, are characteristic of working
memory tasks that require an individual to keep two or more sets of elements
"alive" in short term memory and alternate between performing
operations on the two sets of information" (5).
We've
discussed the relations between Executive Functions and Fluid Ability, and
between Executive Functions and Short Term Memory. Now we can come full circle and discuss the
relations between Fluid Ability and Short Term Memory.
Researchers find high correlations
(0.8-0.88) between measures of working memory and measures of Fluid Ability (2).
Lohman and his colleagues (2) note that "critics
complained that some tasks used to estimate working memory in … studies were
indistinguishable from tasks used to estimate reasoning" (2).
"In part, this is a problem of
words. The term working memory connotes too small a construct; reasoning connotes
too large a construct—especially given the way each is typically measured.
Consider first the reasoning construct. In the best of these studies, reasoning
is estimated by performance on a series of short, puzzle-like tasks. More
commonly, it is estimated by a single test such as the Raven Progressive
Matrices that uses a single item format.
Indeed, figural reasoning tests such as the Raven are typically much
poorer predictors of both real-world learning and academic achievement than
measures of verbal and quantitative reasoning. Whether measured by one task or
several short tasks, the reasoning construct is usually underrepresented.
On the other hand, the construct measured
by the series of working memory tests is much more complex than its label
suggests. These tasks generally require participants to understand and follow a
sometimes complex set of directions; to assemble and then revise a strategy for
performing a difficult, attention-demanding task; to maintain a high level of
effort across a substantial number of trials; and then to repeat the process
for a new task with a new set of directions. In addition, many working memory
tasks require individuals to process simultaneously one set of ideas while remembering
another set. Although the individual tasks are generally thought to be easy,
they are certainly not trivial, especially when performed under memory load.
These tasks elicit executive functions such as the monitoring of processes,
controlling their rate and sequence of operation, inhibiting inappropriate
response processes, coordinating information from different domains, and
integrating ideas into a coherent mental model. Such executive functions
clearly overlap with many researchers’ conception of reasoning or even of
general intelligence" (2).
This is quite convincing, but studiesshow that even tasks that measure only Memory Span, without any manipulation,
correlate significantly with Fluid Ability (3).
To summarize, from the point of view of
CHC abilities, we see a great closeness between Fluid Ability and Short Term
Memory. We also see a great closeness
between Executive functions, Fluid
Ability and Short Term Memory.
It may be that these three concepts will
merge in the future to form one psychometric ability. Maybe this ability will be named
"Executive Functions", and Fluid Ability and Short Term Memory will
be narrow abilities within it.
References:
1.
Flanagan, Dawn p., Ortiz, Samuel O. and Alfonso, Vincent C. Essentials of cross battery assessment. Second edition, 2007, Wiley and sons
2. Lohman, D. F., Lakin, J. M., Sternberg, R.
J., & Kaufman, S. B. (2009).Reasoning and intelligence. Handbook of intelligence, 419-441.
3. Fukuda, K., Vogel, E.,
Mayr, U., & Awh, E. (2010). Quantity, not quality: The relationship between
fluid intelligence and working memory capacity.Psychonomic bulletin &
review, 17(5),
673-679.
4.
Diamond, Adele. Executive functions. Annu. Rev. Psychol.
2013. 64:135–68
5.
WJ3COG examiner's manual.
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