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Rat Mothering:
An Example of the Interaction of Neuroscience
and Psychoanalysis
By Michael Jasnow, PhD
When the editors of the
Our second speaker is Siri Hustvedt. Our membership is, in all
likelihood, less familiar with her work. She is, however, like Dr. LeDoux,
eminent. Her reputation derives from her work as a novelist, poet, and
essayist. She has a deep interest in and knowledge of psychoanalysis and
neuroscience.
The third, and final, speaker is me.
Interest in, really, concern for, the relationship between psychoanalysis, neuroscience and the humanities dates to Freud himself. This is common knowledge. Freuds effort to understand the relationship amongst these several realms was a vital spring which nourished his intellectual efforts his entire life. Examination of the interplay between literature and psychoanalysis has been an ongoing enterprise with many practitioners and numerous branches throughout the course of the 20th century. However, meaningful investigation ( non-speculative and data based) of the relationship between neuroscience and psychoanalysis has had to wait. The latter third of the last century witnessed the birth of the broad spectrum discipline of cognitive neuroscience. This is a transcendent pursuit. It unites the combined efforts of many disciplines including: cognitive psychology, developmental psychology, neuropsychology, traditional neuroscience, genetics and molecular biology. It takes advantage of the new and terrifying powers of neuroimaging and genetics in order to capture and synthesize our understanding of the relationship between neural systems and the whole organism as it moves through its (socially embedded ) life.
Because cognitive neuroscience is now able to begin to address complex
questions concerning meaningful aspects of the organism in context (not
simply a stained preparation), it becomes a meaningful and non-trivial
undertaking to link up the findings of such a neuroscience with
psychoanalysis. There is now no
shortage of those workers trained in one or both disciplines who seek to
hunt out points of contact between these realms. One has only to pick up an
issue of Neuro-Psychoanalysis to see for oneself.
Psychoanalysts and scientists and scientists such as Solms, Bucci,
and Panksepp are, if not quite household names, certainly well known in
psychoanalytic circles.
In spite of this crowded field and the availability of many excellent
explorations of the relationship between neuroscience and psychoanalysis, I
did agree to write this brief note on the topic.
In spite of the energy with which points of contact between our field
and neuroscience are now being pursued there are many problems which hinder
a clear mapping out of the points of contact between the fields.
These are areas of potential difficulty which it will not be possible
to take up in such a brief excursion. For example, as analysts, we can call
on quite a few models of mind, even if we stay within a more-or-less
classical ego-psychological structure. There are also what might be called
epistemologic concerns that arise from coordinating data that arise from our
clinical enterprise with the findings of the laboratory. Our work is
confined in a necessarily exclusive manner to human beings, furthermore, and
dependent upon the verbal output
of human beings. There are many people, I am aware of them primarily from
the side of psychoanalysis, who vigorously object to any attempt to
coordinate the fruits of analytic theory and practice with the findings of
the biological sciences. Psychoanalysis lives at the convergence of the
subjective and the objective. As Freud well knew, it is this Janus-like
aspect of psychoanalysis that embodies its unique power and is, at the same
time, its Achilles heel.
Nevertheless, in spite of the difficulties such an undertaking
involves, it does seem supremely necessary to pay attention to the findings
of neuroscience, particularly those aspects of neuroscience that help us to
think more deeply about the template of the human organism. When we think as
analysts, we use clinically grounded templates to help us understand the
complex ways people engage the world. We think in terms of enduring mental
structure, the matrix of internal and external experience, the dynamic
unconscious, and conflict and response to internalized conflict as modes
that guide the organism through life.
In the several pages that follow, I will put forth not a technical
review of neuroscience; but, rather, I wish to bring forward a restricted
sampling of ideas emerging from neuroscience: findings, ideas, implications
that resonate with my own clinical experience; investigations and findings
that I find personally engaging. Thus, the sampling that follows is meant to
be evocative rather than instructive in a formal sense. No effort is made to
be academically rigorous. Rather, what follows serves an iconic function.
These iconic points of reference concern the impact of early mothering, the
roots of resilience, and the plasticity of the central nervous system.
As analysts, we are raised up with the notion that certain forms of
early experience exert a particular potency in determining human
possibilities and outcomes. These types of experiences (again, the word
templates comes to mind), in some non-trivial sense, go a long way in
determining the individuals degrees of freedom. If we seek, therefore, an
evocative correspondence, a sympathetic resonance, with neuroscience, we
would do well to begin such an investigation by examining findings that
emerge from the study of how variations in maternal behavior impact the
development of the offspring.
Thus, for example, it is now well established that differences in rat
mothering profoundly influence how rat progeny move through rat life. How
will mother rats children come to manage stress and strain? Will they be
resilient in the face of the challenges of life or will they be
anxiety-ridden? It is also clear that the nature of rats mothering will
influence, in a significant way, how clever or how dull her offspring will
be.
In this
literature, experimental outcomes are often induced through direct
manipulation by the experimenter. For example, paradigms have been developed
that involve separating the rat pup from the mother for varying intervals
over the course of the first several weeks of life. Other paradigms involve
examining outcomes related to subtle variations in naturally-occurring
maternal rat behavior; such behaviors as frequency of licking and grooming
and arched-back nursing.
What is among the most interesting of the outcomes of such studies is
the finding that the effects of good-enough or, conversely, not-good-enough
rat-mothering emerge along a number of dimensions when the rat has matured
to adulthood. That is, the protective and positive influence of early rat
mothering is seen once the offspring reach adulthood and face adult-size rat
challenges.
For those interested in exploring this work in more detail, I suggest
the work of Meaney et al. (1991), Yamazaki et al. (2005), and Weaver (2004).
In general, one sees that the effective presence of the rat mother during a
sensitive period encompassing the early days of rat life calibrates the rats
adreno-cortical response to stress. This involves systems such as the
hypothalamo-pituitary-adrenal (HPA) axis. Meaney (1991), for example,
demonstrated that variations in the separation of the rat pup and maternal
behavior upon reunion induced a series of alterations in adrenal-cortical-secretory
patterns, hippocampal, glucocorticoid receptor concentrations, and
hippocampal pathology and dysfunction.
As adults, those rats that received good enough handling as pups are
significantly more resilient in the face of stress and strain than their
non-handled brethren. Moreover, and no less important, these well-handled
rats have better memories and can navigate an environmental threat more
successfully than their less-handled rat brothers. It is well established
that over-exposure to glucocorticoids in the hippocampus (a target site of
glucocorticoids) has a corrosive effect upon hippocampal function. This, in
turn, degrades the ability of the not-handled rats memory function.
Good-enough rat mothering early in life, therefore, sets the stage for more
robust tolerance of stress and improved memory function.
It is the case, and quite remarkable, that Meaney and others are able
to establish an unbroken chain stretching from the observable event (the
caring behavior of the good-enough rat mother) to large-scale,
well-understood internal events (the workings of the HPA axis) and, thence,
all the way down to the level of the gene and the molecule.
How is that? It turns out that the kisses of mother rat (kisses being
broadly understood), affects the methylation status of a glucocorticoid
receptor gene promoter in the hippocampus (Weaver, 2004). In effect, when
mother rat licks her pup upon reunion, she not only makes contact with fur
and skin, her licking strikes more deeply than that. She licks all the way
down to the genome. In her good-enough mothering, she licks off the methyl
molecule sitting tightly-bound on the gene. In this way, she sets the
character, the reactivity, of this response system and, thus, the future
course of her offsprings adult response to stress B a chain stretching, in
some non-metaphoric fashion, from the mother to the molecule. This is also
evocative and this, too, kindles our imagination. It enlarges our view of
the power of a mothers kiss.
Here we find that we are witness to the workings, the gears and
wheels, of epigenetics, that which lies on top of the gene. The term
epigenetics refers to what we already know quite well; that is, that the
genetic compliment of the individual cannot be tell whole story. More and
more, we understand that to have a gene is one thing; but how the gene is
deployed is quite another and, indeed, is the key thing. It what way are a
given complement of genes turned on and turned off? What is the intensity
with which such activation takes place?
If we take to heart the image of mother rats kisses lifting off the methyl cap of the gluco-corticoid receptor gene, it serves as a powerful beacon for us in our own endeavors. These findings tell us more about the deep and mysterious connections between what occurs externally, in the surrounding world, and what we experience as our own subjective reality. In this research on epigenetic outcomes of maternal behavior on the rat, we can recognize the echo of Winnicotts good enough mother. These investigations touch upon, and deepen our understanding of, the meaning of the holding environment and the impact of the holding environment upon the developing organism; concerns that we, as analysts take up daily in our own work.
Furthermore, variations in the holding environment, which may appear
to the casual eye as subtle and immaterial, may exert a significant impact
on outcomes (cf. Yamazaki).
We know
very well from our clinical experience how variable people are in their
ability to manage stress and strain. Some people are surprisingly resilient,
others less so. In our consulting rooms, we tend mostly to see the latter;
that is, the less so. As analysts, we make use of a number of concepts to
help us understand the meaning of this less so state of affairs. In our own
thinking and in our discussions with colleagues, we make use of concepts
such as the ego strength, referring, generally, to the individuals ability
to bind up and manage complex psychological forces at the intersection of
the world and the individual. We explore how well able the person is to
accurately assess whatever state of affairs they find themselves contending
with. We wonder how well they can master the conscious and unconscious
factors stimulated by the expectable exigencies of daily life. We note the
range of automatically available defensive adaptations that the individual
can bring to bear to regulate their internal reality, to minimize
non-productive anxiety and dysphoric affect. In general, we expect that the
healthier the individual, the greater the ego strength; the greater the
individuals ability for flexible and adaptive encounters with what life
deals out to them.
These common analytic ideas, resonate with an article in Science
from July 31, 2009, wherein Eduardo Diaz-Ferreira and his colleagues
published findings on the effects of chronic stress on frontal striatal
structures in rats. It will be more efficient and undoubtedly an aid to
clarity if I simply present the abstract of their findings:
Chronic
Stress Causes Frontal Striatal Reorganization and Affects Decision-Making
The
ability to shift between different behavioral strategies is necessary for
appropriate decision-making. Here, we show that chronic stress biases
decision-making strategies affecting the ability of the stressed animal to
perform actions on the basis of their consequences. Using two different
operant tasks, we revealed that, in making choices, rats subjected to
chronic stress became insensitive to changes in outcome value and resistant
to change in action-outcome contingency. Furthermore, chronic stress caused
opposing structural changes in the associative and sensory-motor
corticostriatal circuits underlying these different behavioral strategies
with atrophy of medial prefrontal cortex and the associative striatum and
hypertrophy of the sensory-motor striatum. These data suggest that the
relative advantage of circuits coursing through sensory-motor striatum
observed after chronic stress leads to a bias in behavioral strategies
toward habit. (p. 621)
Diaz-Ferreira tells us two new and important
things. One of these new things is, for us, old and well-known. When rats
are not stressed, they are adaptable and clever. They pay attention to the
outcomes of their behavior. However, when rats are chronically stressed,
they turn stupid. They resort to habit to meet challenge. They cease to pay
attention to the efficacy of their own actions. They fall, in other words,
into a rut. As analysts, we know this state of affairs all too well
(however, not from rats, I presume). This is the new old thing that
Diaz-Ferreira tells us.
The second, and truly new, piece of knowledge
is found in the remarkable precision and specificity of these findings.
Diaz-Ferreira and his colleagues are able to demonstrate clearly and
elegantly that when chronically stressed, rat brains undergo significant
alteration. A specific portion of the rat brain that supports flexible and
adaptive problem-solving atrophies (the medial prefrontal cortex and the
associated striatum). At the same time, that portion of the rat brain that
supports habit expands (sensory motor striatum). It seems likely that those
brain regions that support mental flexibility in rats support something
similar in people.
The phenomena Diaz-Ferreira and his colleagues
describe have the potential to increase our empathic understanding of what
it means for a person to be less so. While it is, again, old news in our
line of work that people, when stressed, regressively revert to ineffective
modes of problem-solving, it is useful to understand that the neurological
underpinnings of this rigidity can be pin-pointed, at least partially, with
such a high degree of precision.
Taken to heart, such findings serve to support
us in our work with that range of individuals who have been terribly
traumatized by life; to use Scheingolds term, those who have suffered soul
murder. It can be especially useful if, in our work with such individuals,
we understand that we are undertaking a necessarily lengthy project that
must involve, among other things, the reprogramming of important parts of
neural architecture.
This leads us, finally, into thoughts
concerning the plasticity of the nervous system. Here, I quote from the
great Spanish neuro-scientist, Santiago Ramon y Cajal, from his treatise
Degeneration and Regeneration of the Nervous System:
In adult centres, the nerve paths are
something fixed, ended, immutable. Everything may die, nothing may be
regenerated.
This notion, of the immutability of the
nervous system, has met a fate identical to that of so many foundational
truths that have served to orient entire fields. That is, we now know it is
false. The human nervous system, it turns out, is neither fixed nor
immutable. It is surprisingly plastic and dynamic. For example, Lowenstein
and Parent (1999) described the persistence of dormant progenitor cells in
the central nervous system of adult mammals. Under the proper conditions,
these progenitor cells can develop into neurons and glia. They go on to
describe a range of conditions, such as injury and illness, that can prompt
neurogenesis.
Following this train of thought leads us to
Eric Kandel, the winner of the2000 Nobel prize in medicine and physiology
who published a special article in the American Journal of Psychiatry
in 1999. He titled his essay, Biology in the Future of Psychoanalysis: A New
Intellectual Framework for Psychiatry Revisited. (American Journal of
Psychiatry. 156: pp. 505-524, April 1999). In brief, Kandels life
work has investigated the alterations in the nervous system that underlie
learning and memory. In this pursuit, he and his colleagues have described
how the process of long-term potentiation modifies the strength of
connections between neurons in the brain. These alterations, governed by
essentially simple sets of rules, lay down the biological basis of learning
and individuality (Scientific American. September 1992, pp. 79-86).
Kandel described his work directly in this way
(quoting from his 1999 essay):
Long-lasting changes in mental functions
involve alterations in gene expressions. Thus, in studying the specific
changes that underlie specific mental states, normal as well as disturbed,
we should also look for altered gene expression ... Animal studies of
alterations in gene expression associated with learning indicate that such
alterations are followed by changes in the pattern of connections between
nerve cells, in some cases the growth and retraction of synaptic
connections. (p. 24)
Kandel then goes on to state (and, here, quite
to the point of our present excursion) that it is intriguing to think that,
in so far as psychoanalysis is successful in bringing about persistent
changes in attitudes, habits, and conscious and unconscious behavior, it
does so by producing alterations in gene expression that produce structural
changes in the brain. (p. 24)
I have described this essay only as an attempt at the evocative. No pretense is made to achieve a comprehensive view of the relationship between psychoanalysis and neuroscience nor do I lay any claim, in any strict sense, to academic rigor. But then, what is it that I mean to evoke in the reader? With this question in mind, it is perhaps useful to review what we have examined in the course of this brief survey. We have seen that the earliest forms of maternal care in a closely related species act to set the calibration for the major neuro-endocrine pathways responsible for the organisms management of stress and strain. We have seen that there is causal chain connecting good enough rat mothering with the lifting of the methyl molecule at the level of the gene. We have also looked into experiments detailing the neural consequences of chronic stress. These experiments demonstrate how stress leads the organism to favor habitual responses over adaptive responses to environmental challenge. Further, it is clear that there are associated alterations in brain structures underlying each type of behavioral bias. Those areas responsible for behavioral flexibility atrophy (shrink), while areas supporting a habit hypertrophy (enlarge).
Finally, we noted that the received wisdom of
the ages is, predictably, wrong. The mammalian nervous system is not
immutable but, rather, plastic and dynamic. It alters significantly in
response to experience. The biology of the nervous system is bidirectionally
attuned. Biology affects experience but, equally profound, experience exerts
its own influence over biology. Nature and nurture do not exist in separate
and static categories. There is only nature/nurture, the boundary is fluid
and this is not a metaphor.
So, once again, the question arises what do I
intend to evoke in the reader? To evoke has two major meanings. Both
meanings hinge on the idea of summoning or calling forth. In current usage
when we think of evocation, of evoking a response, we have in mind something
that summons up a set of particular feelings or experiences. There is,
however, a more ancient meaning, a meaning lying underneath this more modern
sense. In this older usage, evoke means to call forth a demon or a spirit.
As I muse over what we have just reviewed, I find that both senses of these
meanings are called forth.
On the one hand, there is the unalloyed
pleasure that comes with increased understanding. There can be no doubt the
little we have reviewed, which stands in for the broad range, the cascade,
of new knowledge that is the harvest of neuroscience, fills us with delight.
Knowledge is power, and most of us take delight in the expansion of our
sense of power (illusory or not).
On the other hand, I am also aware of darker
and more complicated feelings, mournful feelings, stimulated by our review,
feelings that are in tune with the antique meaning of evoke. While knowledge
is certainly power, it is also the case that new knowledge displaces older
wisdom. Our newfound understanding must, of necessity, shift the balance of
our present understanding. As Yeats said, the center does not hold. Our
reception of this new knowledge gleaned from neuroscience shifts
psychoanalysis from the conceptual center.
Now, it will be said by many that
psychoanalysis was long ago shoved out of the center of the sphere of
organized human knowledge. None of us can find it too novel an experience to
be pushed into an epistomological corner. But, as a psychoanalyst, a man
with a sympathetic, yet not uncritical, relationship with psychoanalysis, I
feel the shift in a not altogether welcome way. I find myself struggling to
capture, in summary form, the more disquieting thoughts that have been
evoked by our review.
It is certainly the case, in this 150th
year of the publication of The Origin of Species, that there is no
room left in any activity that aspires to remain in contact with science for
special creation. The thread that plays out from mother rats kiss to the
methyl molecule sitting on top of the gene will not permit it. We are
compelled to continuity in our theories. All nontrivial aspects of our
theory must fit within and be consistent with the findings of neuroscience.
At the very least, they cannot contravene such findings. In some fashion it
is metaphorical, yet nontrivial, that we are forced to obey a series of
laws. Our understanding of the causes of human action and the nature of what
is therapeutically mutative must obey these laws. But what laws? As an
imaginative exercise I suggest that neuroscience compels us to acknowledge a
law of primates. We are all primates, and this cannot count as too
disturbing. But, as we can also see, we are also very like rats; so, we
need, at least metaphorically, a law of rats. This, however, is not likely
the endpoint and we probably also require a dizzying regress of such laws: a
law of sea slugs, of corn, and, perhaps, of yeast.
These laws require us to acknowledge that any
theory that seeks to make sense of humanity, of how we move through this
world and how we experience the world we move through, cannot be
anthropocentirc. Our theory cannot be constrained to the consulting room. In
that case, it becomes simply another type of hermetic art.
In Beyond the Pleasure Principle, Freud
(1920) wrote:
The deficiencies in our description would
probably vanish if we were already in a position to replace the
psychological terms with physiological or chemical ones... We may expect
[physiology and chemistry] to give the most surprising information and we
cannot guess what answers it will return in a few dozen a years of questions
we have put to it. They may be of a kind that will blow away the whole of
our artificial structure of hypothesis.
Freud was, of course, correct in his sense of
what was to come. Any serious attempt to understand the implications of the
findings of neuroscience (broadly understood) leads us to the point where
the whole of our artificial structure of hypothesis is, indeed, blown
away.Any attempt to construct psychoanalytic
theory that relies over much, too exclusively, on symbolic processes,
on language, on meaning, as alone cannot, ultimately, meet the demands of
the Law of Corn, Primates and Sea Slugs.
Yet, we also know and acknowledge that even
after the whirlwind something survives. There is no time left to touch upon
the handling of what survives, how psychoanalysis can address the questions
put to it by neuroscience. It does seem to me, however, that, paradoxically,
our understanding of language as an extra cortical organizer (to use Lurias
term) and our understanding of the cognitive and neural aspects of the
executive functions offers a useful pathway that can forge at least one of
the necessary links to usefully anchor psychoanalysis to neuroscience. For
example, Paul Grays close process approach lends itself to such an
investigation. However, these musing have already gone on far too long and
any further thoughts must await another occasion.
Citations to Neuroscience and Psychoanalysis Article for LOOP
Michael D. Jasnow, Ph.D.
Diaz-Ferreira, E., Sousa, J. C., Melo, I., Morgado, P., Mesquita, A. R.,
Cerqueira, J. J., Costa, R. M., Sousa, N. (July 2009) Chronic stress causes
frontostriatal reorganization and affects decision-making. Science.
325 (5940), 621-625.
Freud, S. Beyond the Pleasure Principle. 1920. In Complete
Psychological Works. Standard Edition. Volume 18. London, Hogarth Press.
1955. pp. 7-64.
Kandel, M.D., E. R. (1999).
Biology and the future of psychoanalysis: A new intellectual framework for
psychiatry revisited. American Journal of Psychiatry. 156,
505-524. (8
1999 American Psychiatric Association)
Kandel, E. R., Hawkins, R.D. (1992) The biological basis of learning and
individuality. Scientific American. 267 (3), 52-61.
Meaney, M. J., Mitchell, J. B., Aitken, D. H., Bhatnagar, S.,
Bodnoff, S. R., Iny, L.
J., Sarrieau, A. The effects of neo-natal handling on the development of the
adrenocortical response to stress: Implications for neuropathology and
cognitive deficits in later life. Psychoneuroendrocinology. 16
(1-3), 85-103.
Weaver, I.C., Cervoni, N., Champagne, F.A., D-Alessio), A.C., et al. (2004)
Epigenetic programming by maternal behavior. Nature Neuroscience.
7 (8), 847-865.
Yamazaki, A., Ohtsuki, Y., Yoshihara, T., Homa, S., Honma, K-I. (2005).
Maternal deprivation in neo-natal rats of different conditions affects
growth rate, circadia clock, and stress responsiveness differentially.
Physiology and Behavior. 86, 136-144.
y Cajal, S.R., & May, R.T. (Eds.). (1959) Degeneration and Regeneration of the Nervous System. (Vol. 11). New York: Hafner. (p. 750).