Paul
D. Heideman--Research
Curriculum vita (pdf file)
COPIES
OF PUBLICATIONS (1990 & after)
Copies of
Publications (1981-1989)
Materials
for Evolutionary Physiology Lab Research Students
Research Topic Outline
I. Research on Learning and Studying
II. Research on Neuroendocrine Physiology
CURRENT
RESEARCH
I. ON LEARNING
What methods help students learn,
particularly in mathematics and the sciences?
1.
What are our questions?
Researchers in neuroscience, cognitive psychology,
and education have learned a tremendous amount about how learning works and
how learning happens. That knowledge
is changing how teachers teach. More
and more, instructors from the K-12 through college level are trying to apply
that knowledge to transform teaching.
It is proving surprisingly difficult – our classes are often not very
different from how they were 20 years ago.
One possible problem is that almost all of our attention is focused on
changing teachers and teaching, not on changing students and their choices to
learn.
In the newest research area in my lab, we
focus on changing students. Even
though researchers have learned a great deal about how to study effectively,
we don’t seem to give this information to students. The most common way that most students
study is rereading text or notes, rewatching
videos, or visually reviewing images and PowerPoints. Research tells us that this is a study
method of low effectiveness: visual review makes it take longer to master and
retain information than some other methods, such as ‘retrieval practice’. A problem for students, though, is that
these other methods take time and coaching to apply. Once learned, students find these other
methods to be faster, easier, and more interesting. Researchers know all of
this, but we don’t tell students. We
know all of this, but we don’t teach students how to apply these faster,
better methods.
In my lab, my students and I are testing
ways to help students manage their own learning. We want students to know how to use
effective methods for particular tasks.
We are studying how to help students gain accurate information about
their own learning, learn how to use new study methods quickly and easily,
and in the end, learn more in less time.
This isn’t easy: it takes effort and practice to master better ways to
learn. We’re trying to make that
process faster.
2.
Is drawing and imagining valuable?
In the sciences, it is essential to be
able to perceive structures and events in our imagination. It doesn’t have to be with our eyes: I
argue that it is just as important to be able to imagine those structures and
events as if they were floating in front of us. Every scientist does this, as far as I can
see, often without thinking. If I tell
a fellow scientist to close their eyes when describing their research, they
first look at me oddly. As they close
their eyes and begin to talk, nearly always their hands begin to move in the
air, shaping what they are describing. When I know their topic, especially in
neuroscience, I recognize what they shape: brain areas, cells, or signaling
pathways. It is as if their topic is
floating in the air between us. If I
stop them abruptly to ask, “what’s in your mind right now?” they always say “I
have an image of X in my head.” This
is clearly a skill that scientists develop.
It seems that all the scientists I know develop it. There is some research showing that this
kind of skill can be critical for success in some fields (engineering, for
example). So why don’t we tell our
students about this skill? Why don’t
we teach students how to develop that skill for themselves?
3.
Teaching students to draw and visualize.
Both drawing and visualizing seem to be
useful. When I meet former students
who have continued their education for advanced degrees (graduate school,
medical school, or veterinary school), I ask them how they study, and I ask
them if there is anything they learned in college that they still use for
studying. The most common answer is “I
still draw”. (The second most common
answer is, “I make concept maps”.) Often I hear, “I couldn’t learn all this
without drawing”. Students who learn
how to draw as part of studying often feel that drawing is essential for
their higher-level learning.
Research shows that drawing improves
recall: what we draw we remember better than when we spend the same amount of
time in visual review. That alone is a
benefit of spending some of our study time drawing. But drawing has more uses. Drawing also helps us explain things to
others. Drawing helps us think through
complex problems, in the same way that writing down a math problem on paper
helps us solve it. Complex structures
or events have too many pieces to hold in memory. Drawing them allows us to focus on different
parts of the problem and break the problem into steps, just as we do when
solving a math problem on paper. Done well, drawing students can master
material better and remember it longer.
My lab studies the process of learning to use drawing and
visualization to learn.
Some students draw easily and naturally,
but they spend too much time on each drawing, so it takes too long. Some students make simple drawings, but
they don’t yet know how to turn words or a textbook image into a useful
drawing. To use drawing effectively as
a study method, students need information and practice. They need to know why drawing can
help. They need to learn what aspects
of drawing are most useful. They need
practice and feedback as they apply drawing to their studying.
And many students need to be pushed to
keep practicing. I’ve had many
students tell me, “I hated it at first, but because you made me keep going,
now I see how useful it is, and I’ve kept on drawing ever since.” Those comments tell me that we need methods
that will give students information, practice, and feedback for a long enough
time for them to get good enough to draw effectively. It’s like learning to ride a bike. It would be easy to quit because, “This is
stupid! I keep falling down and
getting hurt. Look at all my scrapes
and bruises! A bicycle is an idiotic machine.” That’s true. Until we’ve practiced enough to discover
how fast and far we can go.
4.
Our research.
We study methods to give students
information about learning combined with ways to improve their studying. Our current focus is on drawing, because
that’s where we see the most need and the most benefit. Our first paper is listed in my publications:
“Effectiveness
and Adoption of a Drawing-to-Learn Study Tool for Recall and Problem Solving:
Minute Sketches with Folded Lists” with my student coauthors K. Adryan Flores, Lu Sevier, and Kelsey Trouton. You can find it at http://www.lifescied.org/content/16/2/ar28.full
We have new projects to explore ways to
assess drawing and help students learn how to use drawing to learn in science
and mathematics. Nearly all of these
projects involve student coresearchers.
Finally, we have been developing projects
on a few other aspects of learning.
One current project is designed to help students discover, for
themselves, whether it matters for their learning or on exams if they get
enough sleep. Most students are
sleep-deprived; most students are hurting their learning more than they
realize.
II. ON NEUROENDOCRINE PHYSIOLOGY – my older
projects
Natural Variation in how the
Neuroendocrine System (Brain and Hormones) control the Body
We
are still doing research projects in neuroendocrine physiology, but
increasingly my students and I are focusing on learning – on how humans best
study and learn to master and retain new information and new skills. We are starting very few new projects on
the topics below.
1. What are our questions?
Do human brains function optimally, or are our brains riddled with
poorly functioning parts and connections? No one knows the
answer. This specific question is at the heart of a major question in
biology. To what extent does natural selection optimize complex systems
such as brains?
The big questions in my
research arise from this question on optimality of complex systems.
First, how much variability is there in complex brain pathways, and, second,
how do complex brain pathways evolve? The complex brain pathway we
study is the neuroendocrine pathway that uses seasonal changes in photoperiod
and other cues to regulate fertility. We study the nature and amount of
variability within species, and try to understand the importance of that
variability. Why does this matter? This is fundamental basic
science research into the aspects of brain function that make individuals
physiologically unique. Understanding this variation is important in ecology, in evolutionary biology, and in
medicine. (How
and why is this important? Click here.)
2. What are our study systems, or
'models'?
My laboratory uses two different study animals (or
'models') in order to get at questions on variability in two different ways.
To understand why we need two different models, consider this problem: in
natural populations of humans or other mammals, every individual is different
both in their genes and in their environment during life. Thus, when we
measure physiological variation in natural populations, it is very hard to
determine how much of the difference is due to genes, to environment, and to
measurement error. (This problem is the reason we know so little about
the sources of natural physiological variation, despite it's
importance.) Laboratory rats and mice have been inbred to the point
that many laboratory strains, such as the Sprague Dawley
strain of rat, have relatively low levels of genetic variation when compared
to wild populations of mammals. Biomedical researchers also have
created 'inbred' strains in which all individuals are (very nearly)
genetically identical by brother-sister mating for at least 25 successive
generations. This makes it possible to study genetically identical
individuals within a strain, but these strains no longer contain normal variation!
Even if we compare different inbred strains, we know that none of the strains
is quite natural in genetic terms. For one thing, these inbred strains
are homozygous at all loci (which is not normal in itself), and therefore
typical inbred rats are homozygous for one or more deleterious recessives
that would very rarely be homozygous in a wild population. In addition,
no strain carries alleles that are lethal as homozygotes but have slight
effects, potentially even beneficial effects, as heterozygotes. As a
result, we've chosen to study a wild rodent species as a model that contains
natural variation, and also a laboratory rat model to let us isolate known
genetic differences. (Click here for more on
how we use these two models.)
Our goal is to
use these two species as model systems for natural variability in complex
brain pathways. We would like to be able to predict the kinds of
complex brain variation in humans and other mammals, to be able to predict
how natural populations of mammals will react to particular kinds of
selection pressures (such as climate change), and even to be able to use this
information to solve questions in clinical human and veterinary medicine.
What do we do, and what kind of results
do we get?
Our research has included ecological field work,
artificial selection, quantitative and classical genetic analyses,
photoperiod manipulations to test daily and seasonal rhythms, hormone
measurements or hormone manipulation, brain manipulation by such things as
neurotransmitter agonists or antagonists to stimulate or inhibit particular
neural pathways, and the use of immunocytochemical
techniques and autoradiography with computer image analysis systems to
identify particular neurons in the brain. I have three current research
areas. The first project examines variation in the neural pathways that
regulate seasonal reproduction in field mice, Peromyscus leucopus (the
"white-footed mouse"). We have tested the heritability of
seasonal responses (and continue to study their genetics), and have been
examining variation in the neuroendocrine components of this brain pathway.
We have found variation in daily rhythms (the biological clock), variation in
the abundance of melatonin receptors, in the number and location of
immunoreactive GnRH neurons, in food intake, and in the way some individuals
respond to food (but not leptin, the 'fat' hormone discovered
recently). The second project is a similar series of studies on several
strains of laboratory rats, most of which are seasonal, and one is not.
Some of our results here have implications for studies on aging as well as on
reproduction. Finally, a third research area involves mathematical
analysis and modeling of populations that contain genetic variation in winter
reproduction and in neuroendocrine physiology. The latter project is
conducted with collaborators in biological mathematics.
What do students do?
Almost all of my research involves undergraduates and masters
students. Many, perhaps most, of these are true collaborations in which
students develop ideas, do experiments, and write manuscripts. In all
cases, students work on at least one of these
elements, though not everyone actually contributes something we can report as
new findings. At any given time there are 8-15 undergraduates and 0-2
master's students in the lab, some just beginning and others finishing up
their experiments, working in my laboratory. Usually we have a research
technician who assists with some student projects and also carries out
her/his own projects with me. We have
had several postdoctoral fellows (recent Ph.D.'s) who helps me run the
laboratory and also teaches in one semester, though we do not have a postdoc
as I am revising this section in 2012. I like to stay in touch
with former students, and I love updates, but I'm not very good at posting
updates to the web! [A badly out-of-date file: (Click here for a list
of students and where they are now--updates or corrections will be
appreciated!)]
Finally, what can
we say about our big questions to date?
First, there are high levels of selectable variation in the
photoperiod pathway in this single population of mice. There is
variation in so many traits that I infer the variation exists in multiple
genes, and probably many genes. There are hints that variation in one
trait may not always match variation in another. For example, at least
occasionally it appears that mice with no sperm in the winter may,
nevertheless, attempt to mate, suggesting that they shut down spermatogenesis
without shutting down the behaviorally expensive and risky behaviors
associated with mating. In addition, it appears that maintaining the
ability to breed in the winter may require higher food intake (a 'cost of
reproduction'), but mice with that ability eat more even in summer
photoperiods! That high food intake in summer suggests that the
potential for winter mating also carries with it a higher cost of
reproduction in the summer. We have also found a large amount of
genetic variation in the number of GnRH neurons we can detect with labeling,
and significant heritability for number of GnRH neurons; recent unpublished
data indicates heritable variation in other types of neurons as well.
The story isn't complete yet. However, putting this all together
suggests that this pathway is not 'optimized'. Rather, the population
carries variation at multiple alleles. Different combinations of those
alleles are probably successful at some times and in some microenvironements,
but not others. However, because the environment is highly variable
from year to year, and from place to place, selection never consistently favors
any single combination of alleles. The result appears to be a highly
variable population, some of which have combinations of alleles that may be
badly matched to where they happen to be born, and others have combinations
of alleles that just happen to be well matched to where they happen to be
born. Probably few or none of these variable alleles are strictly
deleterious--they're just different, and good or bad for an individual
depending upon individual context and environment.
How might this apply to humans?
If human populations are similar, then we might expect high
variability in the details of how our brains regulate such things as
reproduction, feeding, stress, behavior, and biological rhythms.
Further, we might expect specific combinations of alleles for these
neurophysiological control mechanisms to be effective in some situations, but
not others. Humans may have combinations of alleles that may be badly
or well matched to where and how we live. Probably few or none of these
variable alleles are strictly deleterious--they're just different, and good
or bad for an individual depending upon individual context and environment.
Publications
68 research and
review papers
Publications: 1990 & after
Publications:
1981-1989
[Heideman
Home Page]
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Last updated 6/1/17
College of William and Mary, Department of
Biology
pdheid@wm.edu
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