=Paper=
{{Paper
|id=Vol-2384/paper13
|storemode=property
|title=Adding Intelligence to a Textbook for Human Anatomy with a Causal Concept Map Based ITS
|pdfUrl=https://ceur-ws.org/Vol-2384/paper13.pdf
|volume=Vol-2384
|authors=Ben Kluga,Manohar Sai Jasti,Virginia Naples,Reva Freedman
|dblpUrl=https://dblp.org/rec/conf/aied/KlugaJNF19
}}
==Adding Intelligence to a Textbook for Human Anatomy with a Causal Concept Map Based ITS==
https://ceur-ws.org/Vol-2384/paper13.pdf
Adding Intelligence to a Textbook for Human Anatomy
with a Causal Concept Map Based ITS
Ben Kluga1, Manohar Sai Jasti1, Virginia Naples2, and Reva Freedman1
1 Department of Computer Science, Northern Illinois University
benkluga@gmail.com, {mjasti, rfreedman}@niu.edu
2 Department of Biological Sciences, Northern Illinois University
vlnaples@niu.edu
Abstract. The need for intelligent textbooks is keenly felt in the field of anatomy
where students find the breadth and depth of the material challenging. To
properly handle the complexity of the subject, a hierarchical causal concept map
based ITS platform was developed. This system features a general purpose archi-
tecture which takes as input a specific instance of a concept map, allowing au-
thors to build multiple ITSs for different topics. This system improves on its pre-
decessors by introducing additional components to the concept map as well as
multiple types of relationships. These improvements allow students the oppor-
tunity to interact with the topics at a deeper level than required by traditional
textbooks.
Keywords: intelligent tutoring systems, biology education, teaching anatomy
and physiology
1 Introduction
Human anatomy is required for both undergraduate and graduate students in health re-
lated disciplines. This subject is a significant part of the early curricular foundation in
these fields. Anatomy is complex, rich in both fact and concept, and emphasizes inte-
gration of many levels of understanding. Undergraduates studying anatomy at Northern
Illinois University include majors in the health related professions, from pre-physical
therapy, premed and predental to nursing and med tech. Other students taking anatomy
include physical education and biological sciences majors. Graduate programs requir-
ing anatomical study include physical therapy and graduate students in biological sci-
ences. Other universities with medical and dental schools also teach this subject.
The Northern Illinois University anatomy curriculum is divided into lower level un-
dergraduate courses in functional human anatomy and anatomy and physiology (junior-
senior 300 level). Upper level courses are for graduate biology students and physical
therapy majors (400-500 level). This is a typical distribution of course types and levels
across universities. Regardless of major or course level, students find anatomic topics
difficult because they require simultaneous understanding of many disparate bodies of
2
fact. The demand for high informational integration from many subfields of biology is
the crux of the difficulty that students face in learning human anatomy.
There are two traditional ways to teach anatomy. The first is the systemic approach,
where the components of each anatomic system are described and discussed inde-
pendently. While this approach provides an understanding of all aspects of each ana-
tomic unit, it neglects the interrelatedness that allows all body systems to function to-
gether. The second method is the regional approach, in which all anatomic systems in
each region are studied simultaneously. This permits understanding of the interrelation-
ships among different systems, but fails to demonstrate how these components relate to
their native system in all other body regions.
Another problematic aspect in anatomy teaching is the requirement to increase the
depth of understanding students achieve of each anatomic system. For example, one
level at which the muscular system must be understood is identification of all muscles
that move body parts. However, a deeper level requires assimilation of the details of
muscle structure as a tissue, i.e., the ability to differentiate skeletal (= voluntary) and
autonomic (= involuntary) muscles. An even more detailed level is the mechanism by
which muscles move (the sliding filament theory of muscular contraction). The role of
muscle as a body tissue can be understood at the cellular, and molecular and biochem-
ical, levels as well.
All of these concerns relate to structure as well as function, which is also often de-
scribed as physiology, and to understanding the muscular system in the human body.
Muscles move bones, but this fact reveals little of the story until an understanding of
how each muscle or muscle group moves the bone or bones to which it or they attach
or attaches. Assembling all of these levels of knowledge nevertheless falls short of a
full understanding of this system, because functional interpretations are required to
know the results of the movement of each muscle or muscle group. A specific example
of the complexities relating structure to function is exemplified by the diaphragm. It is
the main muscle that controls intrathoracic volume, but increasing respiratory demand
stimulates sequential contraction of additional muscles. These changes are mediated by
the nervous system, but are also correlated with body movements determined by gait.
Anatomy teaching methods can explore these different depths and breadths of study,
but the high degree of integration of understanding of structure and function at all levels
of detail simultaneously requires a clear plan. Many attempts have been made to pro-
vide facts and concepts integrated with the functions of anatomical systems, but be-
cause of the complexity of these interrelationships, anatomic study would benefit from
a new approach, using Artificial Intelligence (AI). The purpose of this research project
is to provide a new model for the teaching of anatomical information in an integrated
manner at a consistent level of complexity.
Students face three main challenges in learning anatomy. First, this subdiscipline of
the biological sciences requires mastering many different detail heavy explanations to
understand each topic. Students find that learning the amount of detailed knowledge
required is overwhelming. This is not only because of the discreet nature of each body
of fact that they must know, but also because the effects of many highly detailed expla-
nations of structures or functions upon each another are all essential to comprehend the
larger conceptual framework.
3
The second problem is to understand the timing of anatomical and functional activ-
ities in the body. Inconveniently, many of these occur simultaneously. Each student
must engage in the mental juggling of ideas to follow the anatomical pathways they
must comprehend for each topic.
The third requirement of students seeking to master the topic is to learn to build a
hierarchy of ideas to know when each component of the matrix comes into play. This
failing is exacerbated by the No Child Left Behind philosophy of “teaching to the test”
(see, e.g., [8]). This teaching method is defined as students memorizing by rote an an-
swer to a specific question. There is no overlap of ideas which would provide context
for the information. Equally significant, the relative contribution to the entire picture of
events as a summation of these ideas, concepts or processes is not defined. Therefore,
all idea complexes have equal importance and no specific relationship can be discerned
among them. As a result, students are overwhelmed with what they consider to be dis-
parate unrelated bits of information.
Standard textbooks for these courses, e.g., the popular ones by Tortora and Nielsen
[10] for lower-level courses or Moore et al. [6] for upper-level courses, do not help
students overcome these challenges. Even the available supplements to the most com-
monly used texts merely reiterate the same information. The forms of the exercises may
differ, but the manner in which the content is presented remains the same. In some
cases, supplement and test bank questions and answers, even with novel accompanying
diagrams or other illustration forms, repeat the information already presented. While
repetition is an aid to learning, it fails to generate a deeper understanding of the material
inherent in the course.
2 Causal Concept Maps
The term “concept map” can refer to a large number of diagrammatic approaches to
human knowledge [7]. Because causality is one of the main concepts underlying the
material students need to learn, we were specifically interested in concept maps that
could represent several different forms of causality. We named our approach causal
concept maps. Since an understanding of hierarchical levels is another core concept that
students have trouble learning from conventional textbooks, our concept maps are hi-
erarchical, i.e., each item can be considered as a process which could have its own
lower-level causal concept map, similar to the decomposition of activities in UML ac-
tivity diagrams [3, ch. 11]. These aspects of the system are important for different rea-
sons; while causality is fundamental to the biological processes, hierarchy is more im-
portant for teaching as students have difficulty connecting seemingly disparate pieces
of information.
In order to design a system that could process these causal concept maps, we needed
to develop a rigorous definition. A causal concept map is composed of rectangles and
arrows, with rectangles representing components of the system and arrows representing
relationships between those components. There are two kinds of rectangles: simple rec-
tangles and those with double bars. A simple rectangle represents a single component
relevant to an anatomical model of the cardiovascular and respiratory systems. The
4
double bars indicate that a significant summary of components and relationships has
been made and is contained within the double-barred box. There are also four kinds of
arrows in the diagram: a plain, black arrow; a white, hyphenated arrow; a white, equiv-
alency arrow; a curved, black arrow. A plain, black arrow represents a causal relation-
ship. A white, hyphenated arrow represents that one component permits another to oc-
cur. A white, equivalency arrow indicates a mathematical equation; the components
involved form the expressions. Finally, a curved, black arrow means “is sensed by,”
indicating a causal relationship of a different variety: a chemical relationship noticed in
the blood.
Rectangles contain information related to the component they describe. Names of
the components appear in lowercase letters unless they are abbreviated. Within this
description, components referred to by name will be italicized. Additionally, there are
potentially two pieces of information within parentheses inside a rectangle. The type of
relationship a component has with the component that preceded it, direct or inverse
respectively, is indicated by a capital I for increasing or a capital D for decreasing.
There may also be a synonym or abbreviation contained within parentheses inside a
rectangle, e.g., intercostal muscle contraction amount may also be known as “muscle
recruitment.” The small, circled numbers next to some of the rectangles indicate the
number of components with which a particular rectangle has a causal relationship. This
is only done when the number affected is greater than one.
The choice to summarize some of the components with the double-barred box nota-
tion can be explained as follows: by focusing on components relevant to an anatomical
study of the cardiovascular and respiratory systems, cognitive load on students could
be reduced and a consistency of scale achieved across the diagram. Additionally, there
is a time constraint to consider: as other topics must be covered in the course as well,
only the content which is necessary appears. As introductory undergraduate anatomy
courses provide an anatomical overview of the cardiovascular and respiratory systems
instead of a physiological one, cellular metabolism is contained within a single, double-
barred box as the elements within constitute the field of histology. On the other hand,
respiratory volume, another double-barred box, is expanded as its composite elements
fit properly within the field of anatomy. One may see the five components which com-
prise respiratory volume expanded along the bottom of the diagram.
Entry to the concept map is through oxygen demand/oxygen supply at the top of the
diagram. The concept map both begins and ends with oxygen demand/oxygen supply as
the body is a homeostatic loop, in other words tending towards stability. In general, the
concept map may be read top-to-bottom, until the point at which it loops back to the
beginning with the arterial system carrying capacity box on the left side of the diagram
and the respiration box on the right side of the diagram.
5
Fig. 1. Causal concept map for our system.
3 An ITS Based on a Causal Concept Map
We are developing an ITS platform that can be used as a basis for any ITS based on a
causal concept map of the style described above. We are building an ITS for the cardi-
ovascular and respiratory systems using this platform to see how well it does as an
intelligent adjunct to a conventional textbook. We plan to test it on students taking
6
Table 1. Sample problems from our ITS.
Scenario:
Mr. C. is walking to the bus stop when he sees the bus. He starts running to catch
it, but feels short of breath and has to stop and rest.
Question 1: (multiple choice)
What is the first event represented in the model in Mr. C’s physiology that caused
him to feel short of breath?
Question 2: (via GUI)
List all of the events in the model, in the order in which they occur, that explain why
Mr. C felt short of breath.
Functional Human Anatomy in Fall 2019. Our ITS is based on the conceptual architec-
ture outlined by VanLehn [11] and used in earlier causal concept map based ITSs such
as Circsim-Tutor [2]. Circsim-Tutor is simpler than the current system in multiple ways.
Its concept map only contains about 10 items at a single level with one type of causality.
All of the relationships it covers are within cardiovascular physiology, and the system
can only ask the user a small number of distinct questions.
Our system is based on a set of scenarios based on the topics covered by the causal
concept map in Figure 1. A sample scenario is shown in Table 1. Each scenario comes
with a set of questions; two sample questions are shown in Table 1. The system is cloud-
based and uses a GUI. Some questions rely on the GUI for complex answer handling,
such as sorting a list of items, while others allow students to type single words or short
answers. When a student gets a question wrong, the system can choose one of several
kinds of hints. The system identifies the correct answer by tracing the scenario in the
concept map just as it is asking the student to. Similarly, the concept map can be used
to generate hints, using algorithms similar to those suggested by Hume et al. [4] and
Zhou et al. [12].
4 Content
Compared to traditional textbooks, the use of a causal concept map based ITS provides
three obvious benefits to students of anatomy. Causal concept map based ITSs provide
students with opportunities to connect facts and concepts learned separately, require
students to build hierarchies among these same elements, and finally emphasize to stu-
dents the simultaneously occurring nature of the processes detailed.
Returning to the example of the diaphragm, one might imagine a student reading
about its role in the cardiovascular and respiratory systems from the glossary of a text-
book: diaphragmatic contraction amount is the amount of contraction in the parachute-
shaped muscle which encircles the base of the lungs and comprises the major muscle
involved in breathing. While there are several important pieces of information here, it
7
is hardly a complete picture. The diaphragm is the major muscle involved in breathing,
but there are others. The process of breathing is mentioned, but its mechanics are not
detailed. Furthermore, the system which controls the muscles themselves is omitted
entirely. Without a method for integrating so many pieces studied in isolation, the
higher levels of Bloom’s taxonomy [1] will often be unreachable.
A causal concept map based ITS provides students with the same facts and concepts
as a textbook, but with an opportunity to make enhanced connections among these ele-
ments through testing (see, e.g., [9]). Students answer questions, receive hints, and in-
terpret materials, which allows not only flexible retrieval of knowledge but organiza-
tion as well. Rather than simply memorizing that a chain of events in the nervous system
exerts sympathetic, or unconscious, control over the lungs, students are able to see how
structure relates to function by connecting the different components through the inter-
active questioning provided by the ITS. Consulting the expansion of respiratory volume
box in the diagram, diaphragmatic muscle contraction amount can be seen to affect
intercostal muscle contraction amount, allowing breathing to take place passively as
the increase in thoracic space lowers interior pressure relative to the atmosphere, all of
which is permitted by a chain of events in the nervous system. This increased grasp of
the material allows students to evaluate information and see the connections between
situations, for example, a change in altitude, an increase in activity level, or a faulty
pacemaker.
In this way the ITS requires students to form hierarchies among these facts and con-
cepts by answering questions related to the relationships among the elements, thereby
connecting pieces of knowledge. Within the hierarchy of the cardiovascular and respir-
atory systems, diaphragmatic muscle contraction amount can be seen to be a part of
the respiratory volume box, which itself composes half of the respiration box. All three
of these components are permitted by the chain of events in the nervous system box,
which can itself be seen to be the eventual result of an increase in oxygen demand/oxy-
gen supply which the increase in respiration permits. There are so many processes
within processes that their interaction and simultaneous occurrence resist simple, linear
description. This issue is exacerbated by the regional versus systemic approaches to
anatomy.
With a systemic approach, students come to understand deeply the innerworkings of
a single system throughout the entire body. To achieve this understanding however,
much of the rest of the body of knowledge must be sacrificed. With a regional approach,
students study the components which comprise a particular region of the body. While
the interaction of the various components in the region of the chest, for example, might
be well understood, how these components fit into the larger systems which comprise
the body remains elusive. The causal concept map based ITS requires students to absorb
both types of information through discussion on which series of components are en-
compassed by respiratory volume, on whether a chain of events in the nervous system
caused respiratory volume to change and on what type of relationship respiratory vol-
ume has with respiration.
This leads to the final benefit: the system emphasizes to students the simultaneity of
these processes. While breathing continues on the right side of the diagram through
respiration, the heart continues to pump blood on the left via cardiac output, the
8
concurrency all the more apparent when the pieces are placed side by side. The process
of breathing forms a continuous loop, air flowing into the space of lower pressure, into
the expanded lungs, or out of the compressed lungs and into the atmosphere. The heart
continuously beats, the blood flowing away through the arteries and back through the
veins. It is only where these two loops overlap that gas exchange occurs, carbon dioxide
is expelled as waste as the blood is reoxygenated, the vital process of cellular metabo-
lism allowed to continue and the body permitted to handle the increase in activity level,
the increase in altitude, or more abstractly, the increased oxygen demand.
The following is a description of the components themselves.
• % Carbon Dioxide Saturation. Percentage of carbon dioxide saturation refers to
the amount of carbon dioxide saturated blood relative to total blood that can be meas-
ured in one’s arteries. An increase in carbon dioxide saturation is caused by both cellu-
lar metabolism as well as an increase in oxygen demand/oxygen supply as the muscular
system produces carbon dioxide as a byproduct via cellular metabolism. Changes in
carbon dioxide saturation are sensed by the carotid body, a small cluster of chemore-
ceptors near the carotid artery in the neck.
• % Oxygen Saturation. Percentage of oxygen saturation refers to the amount of
oxygen saturated hemoglobin relative to total hemoglobin that can be measured in one’s
arteries, a normal range being 94 to 99 percent. A decrease in oxygen saturation is
caused by increases in oxygen demand/oxygen supply as well as cellular metabolism as
energy is produced at the cellular level with oxygen as a reactant.
• Arterial System Carrying Capacity. This refers to the ability of the arteries to ex-
pand in response to increased blood pressure as cardiac output increases. As blood
circulation increases in the lungs, arterial system carrying capacity increases in re-
sponse to accommodate. A chain of events in the nervous system also permits this in-
crease in arterial system carrying capacity by regulating blood pressure via the medulla
oblongata. An increase in arterial system carrying capacity permits an increase in ox-
ygen demand/oxygen supply as more oxygen-rich blood is carried away from the heart
and back to the body.
• Blood Circulation in Lungs. Blood circulation in the lungs is the flow of blood
through the pulmonary arteries and pulmonary capillary beds where gas exchange oc-
curs. An increase in blood circulation in the lungs is produced by an increase in cardiac
output as the heart pumps more blood through the pulmonary arteries. An increase in
blood circulation in the lungs causes an increase in arterial system carrying capacity
as the increased amount of blood being pumped out of the heart and into the lungs
causes an increase in blood pressure in the arterial system.
• Cardiac Output (HR*SV). Cardiac output is equivalent to the expression heart
rate multiplied by stroke volume. An increase in cardiac output results in an increase
in blood circulation in the lungs and correlates with increases in respiratory rate and
respiratory volume. An increase in cardiac output causes an increase in blood circula-
tion in the lungs as additional blood is pumped out of the heart and through the pulmo-
nary arteries. This increase in cardiac output also correlates with increases in respira-
tory rate as well as respiratory volume as additional oxygen and carbon dioxide are
able to be exchanged due to the increased blood flow through the pulmonary capillary
beds. Increases in either heart rate or stroke volume or both cause increases in cardiac
9
output as cardiac output is equivalent to the product of heart rate multiplied by stroke
volume.
• Carotid Body. The carotid body is a small cluster of chemoreceptors in the neck
near the carotid artery which sense changes in carbon dioxide saturation in the blood.
Sensing a change in carbon dioxide saturation, the carotid body causes a chain of events
in the nervous system which regulates both breathing and blood pressure.
• Cellular Metabolism. This refers to the complex set of chemical changes involved
in energy production which require oxygen and produce carbon dioxide as a byproduct.
Cellular metabolism causes decreases in oxygen saturation and increases in carbon di-
oxide saturation.
• Chain of Events in Nervous System. The events which take place in the nervous
system that relay messages from the carotid body to the brain stem (medulla oblongata)
and then to the appropriate sites within the body. The chain of events in the nervous
system is caused by the carotid body as it senses changes in levels of carbon dioxide
within the blood. The chain of events within the nervous system permits four events
which also impact the chain of events in the nervous system: increases in heart rate,
stroke volume, respiratory rate, and respiratory volume. This is because this chain of
events includes the vagus nerve which exerts sympathetic, or unconscious, control over
the heart and lungs but also receives feedback reflecting the anatomical changes. The
chain of events in the nervous system also permits an increase in arterial system carry-
ing capacity.
• Diaphragmatic Muscle Contraction Amount. The amount of contraction in the
parachute-shaped muscle which encircles the base of the lungs and comprises the major
muscle involved in breathing. Increases in contraction of the diaphragm causes recruit-
ment of the intercostal muscles to assist with breathing, increasing thoracic space and
the volume of air inhaled. Relaxation of the diaphragm increases pressure which causes
expiration (exhalation of air).
• Heart Rate (HR). Heart rate, or pulse, is the number of times one’s heart beats
per minute. Increases in heart rate are permitted by a chain of events within the nervous
system and are caused by increases in oxygen demand/oxygen supply. Along with stroke
volume, increases in heart rate are equivalent to increases in cardiac output.
• Intercostal Muscle Contraction Amount. The amount of contraction in the
muscles situated between the ribs. Intercostal muscles are recruited by the diaphragm
to assist with breathing. Contraction of the intercostal muscles increases thoracic space
and decreases the pressure within, causing inhalation.
• Oxygen Demand/Oxygen Supply. Equivalent to a change in altitude, a change in
activity level, or muscle contraction among other things, the ratio of oxygen demand to
oxygen supply refers to the amount of oxygen required by the body to perform an action
or movement, with the condition of being at rest considered the baseline. For example,
an increase in activity level is equivalent to more, faster and harder muscle contraction,
and itself causes six things to occur within the system: a decrease in the percentage of
oxygen saturation, an increase in the percentage of carbon dioxide saturation, an in-
crease in heart rate, an increase in stroke volume, an increase in respiratory rate, and
an increase in respiratory volume.
10
Increases in oxygen demand/oxygen supply cause changes in levels of oxygen and
carbon dioxide as these resources are consumed and produced via cellular metabolism.
Increases in oxygen demand/oxygen supply cause increases in heart rate and stroke
volume to increase blood flow to the muscles to provide the oxygen necessary to support
the additional activity. Increases in respiration and arterial system carrying capacity
permit an increase in oxygen demand/oxygen supply because increases in arterial sys-
tem carrying capacity allow more blood to be transported back to the lungs where in-
creases in respiratory rate and respiratory rate contribute to oxygenation.
• Respiration. The act of breathing. Increases in respiration are equivalent to
increases in either respiratory rate or respiratory volume or both. Increases in respira-
tion permit increases in oxygen demand/oxygen supply as additional gas exchange oc-
curs, delivering oxygenated blood via the arterial system.
• Respiratory Rate. The number of breaths that one takes per minute. An increase
in respiratory rate, along with respiratory volume, is equivalent to an increase in res-
piration. Increases in respiratory rate are permitted by a chain of events within the
nervous system and correlate with increases in cardiac output as additional blood flow-
ing through the pulmonary capillary beds allows for increased gas exchange. Increases
in oxygen demand/oxygen supply cause increases in respiratory rate.
• Respiratory Volume. The total amount of air within a single cycle of inspiration
(inhalation) and expiration (exhalation). An increase in respiratory volume, along with
increases in respiratory rate, are equivalent to increases in respiration. Increases in the
volume of air in the respiratory cycle are permitted by a chain of events in the nervous
system and caused by increases in oxygen demand/oxygen supply.
• Stroke volume (SV). Stroke Volume is the amount of blood pumped by the heart
in one stroke, or beat. Increases in stroke volume are permitted by a chain of events
within the nervous system and caused by increases in oxygen demand/oxygen supply.
Along with heart rate, increases in stroke volume are equivalent to increases in cardiac
output.
• Thoracic Space. The amount of space within the cavity of the chest. An increase
in thoracic space causes an increase in the volume of air inhaled as pressure within the
lungs decreases. An increase in thoracic space is caused by an increase in intercostal
muscle contraction amount.
• Volume of Air Exhaled. Similar to Volume of Air Inhaled.
• Volume of Air Inhaled. The amount of air inhaled in a single breath. The volume
of air inhaled increases as thoracic space increases. This is because pressure within the
lungs decreases due to the increased space. An increase in the volume of air inhaled
causes an increase in the volume of air exhaled. This is due to changes in pressure
within the lungs, air flowing into the area of lower pressure. During exhalation, pressure
within the lungs is greater than the atmosphere so air flows out. After exhalation, pres-
sure within the lungs is less than the atmosphere so air flows back in, increasing the
volume of air inhaled.
11
5 Conclusions and Future Work
Using an intelligent tutoring system which utilizes hierarchical causal concept maps is
a novel approach to solving a problem that has been resistant to previous standard meth-
ods within the field of anatomy. Undergraduate anatomy students have trouble connect-
ing facts and concepts learned separately, building hierarchies among those concepts,
and understanding that the causal relations between these concepts happen simultane-
ously.
After formalizing the notion of hierarchical causal concept maps, we have developed
ITS software that can process multiple scenarios using a causal concept map for the
cardiovascular and respiratory systems. We have written a simulator for this system [5]
and are also planning to test the system with students taking a variety of anatomy and
physiology classes.
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