Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
Chapter 10 Thinking and Problem Solving
“Recruitment
of executive attention is normally associated with a subjective feeling
of mental effort.”
Lionel Naccache, Stanislas Dehaene, Laurent Cohen, Marie-Odile Habert, Elodie
Guichart-Gomez, Damien Galanaud, and Jean-Claude Willer, 2004
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
Chapter Outline
1.0 Working memory
2.0 Explicit problem solving
3.0 Mental workload and cortical activity
4.0 Using existing knowledge
5.0 Implicit thinking
6.0 Summary
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
Chapter 10 Thinking and Problem Solving
Human problem-solving comes in
two varieties: explicit and implicit.
These two modes differ sharply:
explicit problem-solving has clear,
conscious goals and clearly defined
steps for getting from a starting
point to a solution.
Mental arithmetic is an example of
explicit problem-solving.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
Chapter 10 Thinking and Problem Solving
Human problem-solving comes in two varieties: explicit and implicit.
Implicit problem-solving may be more common than explicit since we learn and
practice many kinds of skills from early on in life. These problem-solving skills
become more proficient, implicit (unconscious), and automatic with practice.
Infants acquiring language is an example of implicit problem-solving.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
Chapter 10 Thinking and Problem Solving
Explicit problem-solving involves greater executive control, higher mental workload,
more frequent conscious access, and wider recruitment of cortical regions in
pursuit of explicit goals.
Implicit problem-solving takes less executive control than the explicit kind, less
conscious access, lower cognitive load, and less cortical involvement.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
1.0 Working Memory
Working memory in the
functional framework
Working memory is constantly
involved in problem-solving,
however working memory
functions also make use of
stored information shown in the
gray boxes at the bottom of the
functional framework diagram.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
1.0 Working Memory
A schematic of brain areas in
the frontal and parietal lobes
that support working memory
processes.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
1.0 Working Memory
Brain regions supporting working memory overlap with those supporting attention,
conscious events, and episodic recall. This widespread activation primarily includes
frontal and parietal cortex.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
2.0 Explicit Problem Solving
Problem-solving can be thought of as finding a path through a maze of choice-points
between possible sub-goals toward a final goal.
A puzzle called the Towers of Hanoi is frequently used to investigate brain areas
involved in explicit problem-solving. The task is to move the disks between the rods,
one step at a time, until that they match the goal.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
2.0 Explicit Problem Solving
Brain areas activated during solving of the Towers of Hanoi include the dorsolateral
prefrontal cortex.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
2.0 Explicit Problem Solving
Flexibility is an important aspect of successful explicit problem-solving. People may get
‘fixed’ in problem-solving strategies: a standard task used to investigate flexibility in
problem-solving strategies is the Wisconsin Card Sorting Task (WCS).
The basic task is for the subject to sort cards, however they are not instructed as to
what the rules are for sorting -- they must extract the rules based on experimenter
feedback regarding whether their sorting is correct or not.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
2.0 Explicit Problem Solving
WCS: possible rules are to sort by color, number, or shape. To be successful, the
subject must be ready to switch his task from, for example, sorting by color to sorting
by shape based on feedback from the experimenter.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
2.0 Explicit Problem Solving
Brain areas involved in adapting to new rules -- or task switching -- overlap with areas
active for other executive tasks in frontal and parietal lobes.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
2.0 Explicit Problem Solving
A current model for brain areas
involved in explicit problem-solving:
on the outer surface of each
hemisphere, peak activity during
problem-solving appears in the
dorsolateral prefrontal cortex
(DLPFC).
During task conflict or errors, we find
high activity in the forward (anterior)
part of cingulate cortex (ACC).
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
3.0 Mental Workload and Cortical Activity
Effortful tasks show a wide spread of
brain activity, even beyond the executive
regions of the frontal cortex.
In a classic fMRI study by Smith and
Jonides, memory load was varied using
an n-back task. In this task, the subject
must hold in mind several trials in order to
report the item that was presented in the
n-preceding trials.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
3.0 Mental Workload and Cortical Activity
Effortful tasks show a wide spread of brain activity, even
beyond the executive regions of the frontal cortex
Results showed a dramatically expanded cortical activity
as a function of memory load.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
4.0 Using Existing Knowledge
Interactivity of short- and long-term
stores
While working memory functions
are typically thought of as dealing
with inputs to the cognitive system,
it is important to note that working
memory systems interact
constantly with long-term stores as
well as with incoming information.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
4.0 Using Existing Knowledge
Working memory constantly activates long-term storage
Cowan (2001) suggests that working memory may be thought of as active and timelimited neuronal activity playing on long-term patterns of structural connectivity.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
4.0 Using Existing Knowledge
Semantic memory plays a key role in
problem-solving. How and where are
concepts represented in the brain?
A recent summary of semantic memory
location in the left hemisphere provides
evidence that semantic working memory
involves constantly looping activity
between the temporal and frontal lobes.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
4.0 Using Existing Knowledge
Abstract concepts, prototypes, and networks
How is semantic knowledge represented in the brain? Do we carry pictures in
our heads that represent the perceptual world around us? Evidence suggests
that we tend to use visual images that are prototypical reminders of categories
like chair or movie star.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
4.0 Using Existing Knowledge
Knowledge comes in networks
Mental representations, including
words, concepts, and images, are
thought to be organized in the brain in
elaborate networks of knowledge.
Ideas appear to be represented in the
cortex in terms of complex webs of
learned connectivities, rather than
localized filing systems with neatly
arranged conceptual categories.
Overlapping semantic networks for
concepts ‘tiger’ and ‘elephant’.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
4.0 Using Existing Knowledge
Conceptual deficits
Some of what we have learned about
cortical representation of concepts comes
from patients with brain damage in regions
that are involved in semantic memory and
conceptual representation.
The specific deficits that these patients
have following brain damage informs us as
to the role of those brain regions in
semantic memory.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
4.0 Using Existing Knowledge
Conceptual deficits
Patient EW had a deficit in naming animals but not in
naming members of other categories, such as faces.
Her deficits were not only in recognizing pictures of
animals, but also in recognizing spoken animal names,
indicating that visual and sound representations of
animals might be located in the same brain areas.
The fact that her deficit was limited to the animal
category indicates that different semantic categories -like animals and faces -- may be stored in differing
brain regions.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
4.0 Using Existing Knowledge
Judgments of quantity and number
Is there a network for number judgment?
To the surprise of many, good evidence
has emerged recently for specific areas
of parietal cortex for number naming and
number judgments.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
5.0 Implicit Thinking
Most human problem-solving is a mixture of
explicit and implicit ingredients. We tend to
underestimate the complexity of implicit
cognition -- precisely because it is unconscious.
In fact, it is our highly expert, overlearned habits
that may be the most efficient tools for solving
problems.
Sudden insight in problem-solving is likely due
to implicit processes at work at the task. EEG
studies have shown that just before making a
correct response, alpha density decreases and
gamma increases. Gamma activity is thought to
reflect active and synchronized processing in
neural networks across the brain.
Cognition, Brain and Consciousness: An Introduction to Cognitive Neuroscience
Edited by Bernard J. Baars and Nicole M. Gage
2007 Academic Press
6.0 Summary
Working memory is the domain of problem-solving
Completely explicit problem-solving is probably rare in the natural
world
Explicit puzzles like the Tower of Hanoi are quite sensitive to frontal
lobe damage; the WSC task can be used to test for mental flexibility in
problem-solving
Effective problem-solving likely entails a mixture of explicit and implicit
processes along with a high degree of mental flexibility