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John Bruer Presentation to The Uses and Abuses of Biology: Neuroscience, Parenting and British Family Policy.

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Presentation by Professor John T. Bruer, entitled 'Distortions of Neuroscience', to the conference The Uses and Abuses of Biology: Neuroscience, Parenting and British Family Policy, Friday 28 March …

Presentation by Professor John T. Bruer, entitled 'Distortions of Neuroscience', to the conference The Uses and Abuses of Biology: Neuroscience, Parenting and British Family Policy, Friday 28 March 2014, Birkbeck, London University. Event organised by the Centre for Parenting Culture Studies, the University of Kent.

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  • The Decade of the Brain was a designation for 1990-1999 by U.S. president George H. W. Bush as part of a larger effort involving the Library of Congress and the National Institute of Mental Health of the National Institutes of Health "to enhance public awareness of the benefits to be derived from brainresearch".
  • This first wave expounded and popularized what I characterized as The Myth of the First Three Years and which I criticized .I go into greater detail about how the cited neuroscience does not support in the myth in the paper posted on the conference web site. But that argument is summarized here.Rapid synapse formation occurs in various parts of the human brain at various times earlyin development. Synaptic densities far exceed adult levelsuntil the age of puberty, when synapse elimination occurs. This process is much more under genetic than environmental controlThis period of high synpatic density does not coincide with any critical period we know about. Certainly learning, in general, is not more efficient or easy at the time of high synpatic density.There are numerous critical periods in development – many such periods within the visual system alone – associated with specific visual functions. The specific neural circuits underlying these critical periods and visual functions are not known in any detail.Environmental enrichment on rats is actually raising rats in laboratory analogs of natural environments rather than under usual laboratory conditions. Such natural environments have effects on rodent brain structure throughout life. We should not generalize from these rodent experiments to humans and conditions of child rearing.
  • This first wave expounded and popularized what I characterized as The Myth of the First Three Years and which I criticized .I go into greater detail about how the cited neuroscience does not support in the myth in the paper posted on the conference web site. But that argument is summarized here.Rapid synapse formation occurs in various parts of the human brain at various times earlyin development. Synaptic densities far exceed adult levelsuntil the age of puberty, when synapse elimination occurs. This process is much more under genetic than environmental controlThis period of high synpatic density does not coincide with any critical period we know about. Certainly learning, in general, is not more efficient or easy at the time of high synpatic density.There are numerous critical periods in development – many such periods within the visual system alone – associated with specific visual functions. The specific neural circuits underlying these critical periods and visual functions are not known in any detail.Environmental enrichment on rats is actually raising rats in laboratory analogs of natural environments rather than under usual laboratory conditions. Such natural environments have effects on rodent brain structure throughout life. We should not generalize from these rodent experiments to humans and conditions of child rearing.
  • The Myth provides a basis for critical appraisal of the brain and early intervention literature that is still relevant.
  • Authors acknowledged over generalization.
  • One characteristic of the brain and early intervention literature is that it tends to make similar claims over and over, usually relying on First Wave documents and commentaries. Also, in some of these policy reports there is a carelessness about or looseness with facts about brain development.For example, the Allen-Duncan Smith report claims that the brain has developed to 85% of its potential by age 3; the Field report says the baby’s brain is 80% formed by age 3; and the Allen report says that be age 3 children’s brains are 80 percent developed. The fact about brain growth is shown in the graph on the right. Mature brain weight is approx. 1.5 kilos. At age 3 average brain weight is around 1.25 kilos (as indicated by the red arrow) and 1.25 is 83 percent of 1.5.However, brain weight or volume present at best physical measurements of the brain. Such measurements say nothing about the state of brain structure or brain function. From this fact, nothing follows about the brain’s potential and functional development, unless one can tell a story about how brain weight correlates or causes brain function or development.
  • This slide appears in Allen & Duncan Smith (2008): Early intervention: Good Parents, Great Kids, Better Citizens. I found around a dozen lectures posted on the web that used this slide. The original source for the slide is Dr. Bruce Perry and can be found on the Child Trauma Academy website. It shows a purported mismatch between public spending over the first 20 years (black line) and brain’s capacity for change over the first 20 years (red line). The red line showing the brain’s capacity for change is not based on any scientific measurement. There is nothing one could measure to get this curve (well one thing brain weight/body weight x 100).Rather the red line expresses a conviction that brain plasticity decreases following a negative exponential over the life span. As an image, it makes a compelling rhetorical point. However, it does not report a scientific finding, supported by data. This slide is not based on data; it is a cartoon. Will see it again later.I asked a neuroscientist who used this slide in one of his talks what the red line was. The answer: “As for the slide, as you know, there would not be one single measure of brain change; it is a conceptual summary to indicate that based on critical and sensitive period data in sensory systems, language, fetal programming, epigenetic influences shown in specific systems, experience-dependent plasticity goes down over a lifetime.”Second wave literature is a little further away from the original science that was First wave literature
  • No citations.
  • Many of the criticisms of The Myth still apply.The article tells a story about how selected neuroscience might support a policy end.Recognizes multiple sensitive periodsNo clear distinction between experience expectant and experience dependent plasticity.Article leads with school based projectsTransitions to attachment theory, then second language learning, then visual deprivation.Minimizes behavioral and neural plasticity over the life spanHighly simplistic (Skills beget skills)Highly reductive , overstating what we know about how circuits and synapses support behavior and confident in the relevance of animal models to human development and learningDevoid of cognitive psychology, developmental psychologyConcerned with when rather than what
  • Source of the metaphorsThis article describes a seven year collaboration between academic scientists and communications experts to “frame” a story based on neuroscience that would help advance applications of neuroscience and psychology to early childhood programs, but more importantly to elicit and facilitate political action to a establish these programs.The scientists, the article says, are committed to developing a message that is true to the science (at least as they interpret it).The process began with scientists involved the MacArthur Research Network on Early Experience and Brain Development. This self-selected group became the National Scientific Council on the Developing Child. Building on the Council’s translation of basic developmental concepts (e.g., notions of sensitive periods and decreasing neuroplasticity over time) to explain why investments in vulnerable young children can generate strong returns to society, the Forum was designed to answer the what, when, and for whom questions about effective programs.This group was committed to incorporating communications expertise and established a partnership with the Frameworks Institute a Washington based think tank that studies the cultural models that people bring to their understanding of science.Strategic Frame Analysis, as developed by the FrameWorks Institute, integrates essential constructs from the cognitive and social sciences intothe study and practice of communications. It relies upon an iterative, multimethod, empirical process to: (a) identify cultural models that people use consistently to reason about a particular issue, (b) compare and contrast these models to the content of expert thinking on that issue, and (c) develop and empirically test powerful frame cues (such as values and metaphors) for their ability to align lay judgments and solutions more closely with expert thinking (Bales & Gilliam, 2004, 2009; Gilliam & Bales, 2001).
  • Clearly in the realm of policy advocacy – framing or spinning?
  • /)
  • Third wave documents turn directly to academic institutions for the source of their material and science.Most prominent of these is the Center on the Developing Child, Harvard University.
  • Characteristics – strength of first wave claims
  • Cover includes iconic brain images produced by Bruce Perry, presented by Perry & Reiner to National Association of Governors in the 1990s (These reports rely heavily on Perry’s materialOutlier in Perry’s data)Little direct academic involvement in preparation of report – rewrite and rehash of 1st wave documents
  • As much about psychiatry as they are about neuroscience. Trend to over-estimate what is known about relationship of psychiatry and brain science.
  • Accompanied by increased scholarly-scientific activity.Integrate economics with neuroscience and child development – James Heckman and colleaguesAbove slide highly reminiscent of Bruce Perry slide showing decay of brain plasticity, but now rate of return to human capital investment.Claimed that this graph summarizes the empirical literature on effectiveness/ cost effectiveness of early vs later intervention. Cunha-Heckman model assumes this summary is accurate. Does not provide independent theory to account for success of early intervention.

Transcript

  • 1. New Scientist January 11, 2014
  • 2. Structure • Early intervention before neuroscience (1960 – 1994) • The allure of brain science (1994 – 2000) • Translating neuroscience into policy (1998 – ) • Some issues and questions
  • 3. Before neuroscience Early intervention 1960 - 1990
  • 4. “In this respect, the ‘cause’ – intervening in the early years to influence ‘parenting’– can be said to have manifestly established itself in policy thinking before the ‘argument’ – neuroscientific evidence that the early years are ‘critical’ – was made by policy-makers.” The Uses and Abuses of Biology: Neuroscience, Parenting and Family Policy in Britain A ‘Key Findings’ Report Ellie Lee, Jan Macvarish, and Pam Lowe
  • 5. This means that nearly half the preschool children of poverty will get a head start on their future. These children will receive preschool training to prepare them for regular school in September. They will get medical and dental attention that they badly need, and parents will receive counseling on improving the home environment. Lyndon Baines Johnson, Rose Garden at the White House May 18, 1965
  • 6. "There is considerable evidence that the early years of childhood are the most critical point in the poverty cycle. During those years, the creation of learning patterns, emotional development, and the formation of individual expectations and aspirations take place at a very rapid pace. For the child of poverty, there are clearly observable deficiencies in these processes, which lay the foundation for a pattern of failure, and thus a pattern of poverty throughout the child's entire life." Recommendations for a Head Start Program by Panel of Experts, Dr. Robert Cooke, Chief Pediatrician, Johns Hopkins Hospital, Chair, February 16, 1965
  • 7. The Evidence “The overwhelming import of this work, which is the tremendous changes that take place in the very early years of childhood and the -- at least as far as our present methods are concerned – smaller changes that take place in later years. … We have come to the viewpoint that, while much can be done for culturally deprived children at various ages, by far the greatest effect can be produced in 1 to 2 years of preschool experiences in the period of 3 to 5.” Benjamin Bloom (1965), Congressional testimony on Aid to Elementary and Secondary Schools Act.
  • 8. Early Intervention ≠ Inoculation In the 1960s, a number of theorists suggested that the first years of life were of extraordinary importance in remediating the academic disadvantages often observed among poor and ethnic-minority children. Moreover, in some cases a more radical suggestion was made: that disadvantaged children could possibly be "inoculated" against their disadvantages by providing them with enrichment experiences in the first years of life. It was implied that, like inoculations against infectious diseases, these enrichments might provide long-lasting protection. The results of the IHDP call into question the notion that providing enrichment experiences in the first few years of life can protect children against biological disadvantages over extended periods of time. Brooks-Gunn et al. (1994), Early Intervention in Low-Birth-Weight Premature Infants Results Through Age 5 Years From the Infant Health and Development Program. JAMA.
  • 9. Head Start Enters Adulthood (1990) • Many educators assume that “quality preschool programs trigger a process that creates a lasting positive effect on young lives. But is the evidence there to support these grand claims? Examination of the research that has been done on early intervention programs since Head Start began in Lyndon Johnson's Great Society suggests it is not.” • “… dozens of studies have confirmed its finding that the intellectual effects of Head Start and similar efforts are short-lived.” (fade out) • “One rarely questioned assumption, says developmental psychologist Sandra Scarr of the University of Virginia, is that "earlier is better" for getting children on the right track. There is quite a mystique in our culture about the importance of early intervention,” Scarr says, yet "there is no evidence [for it] whatever.“” • “ … the latest research on educational intervention suggests that such programs ought to be extended – to the third grade, say – in order to have maximum impact.” • “… the evidence remains shaky enough that few researchers are willing to offer overall policy conclusions.” Constance Holden, Science, 23 March 1990, pp. 1400 - 02
  • 10. The Allure of Neuroscience Early intervention 1990 - 2000
  • 11. • “How individuals function from the preschool years through adolescence and even adulthood hinges, to a significant extent on their experiences before the age of three.” (Starting Points, p.3) • *Starting Points+ “focused on the strong evidence from research on brain and behavior development, indicating long term effects of early experience.” (Dr. David Hamburg, President, Carnegie Corporation) • Discussion of brain science is confined to 2 ½ pages early in SP, added in a later draft to present neuroscience relevant to early childhood (0 to 3 years) policy.
  • 12. • By the age of two, toddlers’ brains are as active as those of adults. By the age of three, the brains of children are two and a half times more active than the brains of adults—they stay that way throughout the first decade of life.” (p. 21) • 85 percent of a child’s brain development takes place by the age of 5. Synapses are created with astonishing speed in the first three years of life. For the rest of the first decade, a child’s brain has twice as many synapses as an adult’s brain. This means that a child’s environment during the first five years of life can greatly impact the brains’ ability to develop.”
  • 13. Why the first three years? Attachment theory • Theory about the dynamics of long-term relationships. • Infants need to develop a relationship with a primary care giver, if social and emotional development is to occur normally. • Infant attachment categorized using Strange Situation Paradigm • ~ 20 minute procedure • Infant behavior when reunited with caregiver • Correlations between attachment category and subsequent development/behaviors extending into adulthood. • [Good mothering+ “is almost useless if delayed until the age of 2 ½ years. In actual fact this upper age limit for most babies is probably before 12 months.” (Bowlby, 1951)
  • 14. “The Myth of the First Three Years”  The first three years of life is a period of rapid synapse formation.  This is the critical period in brain development, during which learning is easiest and most efficient.  During the critical period, environmental enrichment has profound, irreversible effects on the brain.
  • 15. Countering the Myth  The first three years of life is a period of rapid synapse formation, but what these changes in brain structure imply for changes in brain function and behavior is only asserted, not demonstrated. (e.g. Huttenlocher, Chugani, Perry).  Critical (better, sensitive periods) do occur in development but they do not map neatly onto periods of rapid synapse formation, nor is learning easiest and most efficient during this period.  In rodent studies, environmental enrichment increases the number of synapses per neuron in visual areas, but this effect occurs throughout the life span (of rodents).
  • 16. • “ … the recent embracement of “research” documenting the critical nature of the first 3 years of life for brain development although well intentioned greatly exaggerates the actual scientific data on which policy recommendations have been based and actually may undermine policies for vulnerable populations.” (Cichetti & Toth, 2002) • “There has been a misleading extrapolation of the findings on experience- expectant development to the entirely different notion that higher quality psychosocial experiences in the first 2 or 3 years of life will have a much greater effect than similar experiences later, because the early experiences bring about a lasting change in brain from people outside the field of neuroscience research) are misleading and fallacious for several different reasons (Bruer, 1999).” (Rutter, 2002) • Books on early childhood development like The Myth and Scientist in the Crib (Gopnik et al., 1999) take no account of the effects of early trauma, abuse, and neglect on developing brain anatomy. (Schore, 2001) Reactions from the Academic Community http://blogs.kent.ac.uk/parentingculturestudies/files/2011/09/Special-briefing-on-The-Myth.pdf
  • 17. Recognition of over generalization • “ The success of preschool programs and critical periods for first language learning have been used – and misused – to suggest that early experience in general is critical to brain development. (C.A. Nelson, 1999) • “One example was the over generalization of research on critical periods that fueled the erroneous conclusion that human brain development is effectively solidified by the age of 3 years, despite the fact that critical (vs. sensitive periods) in the maturation of the human brain are the exception rather than the rule.” (J. Shonkoff 2000)
  • 18. A Sensitive Period for Attachment? “Sensitive periods can be defined as unique episodes in development when specific structures or functions be come especially susceptible to particular experiences in ways that alter their future structure or function.” “It is doubtful that early attachment security or insecurity influences subsequent development in a manner resembling a sensitive period.” “ … initial attachment provides a provisional foundation for the growth of later psychosocial competencies in the years to come. Subsequent experiences may build on, or alter, this initial developmental pathway.” Ross Thompson (2001)
  • 19. Brain Size versus Brain Development … the human brain has developed to 85 per cent of its potential at age three (and 90 per cent at age four). (Allen and Duncan Smith 2008) By the age of three, a baby’s brain is 80% formed and his or her experiences before then shape the way the brain has grown and developed. (Field, 2010) A key finding is that babies are born with 25 per cent of their brains developed, and there is then a rapid period of development so that by the age of 3 their brains are 80 per cent developed. (Allen,2011) • Fact: By age 3 the human brain has reached around 85 per cent of its mature weight (or volume). 1.25/1.5 X 100 = 83
  • 20. Republished in New Scientist 11 January 2014 p.7, where vertical axis is labeled “Sensitivity to learning.”
  • 21. Translating Neuroscience into Policy Early intervention 1998 - present
  • 22. Economic, neurobiological, and behavioral perspectives on building America’s future workforce Eric I. Knudsen*†, James J. Heckman‡, Judy L. Cameron§, and Jack P. Shonkoff¶ • Central to these principles are the findings • that early experiences have a uniquely powerful influence on the development of cognitive and social skills and on brain architecture and neurochemistry, • that both skill development and brain maturation are hierarchical processes in which higher level functions depend on, and build on, lower level functions, • and that the capacity for change in the foundations of human skill development and neural circuitry is highest earlier in life and decreases over time. • These findings lead to the conclusion that the most efficient strategy for strengthening the future workforce, both economically and neurobiologically, and improving its quality of life is to invest in the environments of disadvantaged children during the early childhood years. PNAS July 5, 2006 vol. 103 no. 27 10155–10162
  • 23. Sensitive Periods in the Development of the Brain and Behavior Eric I. Knudsen (2004) JCNS 16(8):1412 - 1425 • A sensitive period is a time during development during which the effect of experience on the brain is particularly strong. • A sensitive period during which experience is essential for normal development and alters performance permanently is a critical period. • “Although sensitive periods are reflected in behavior, they are actually a property of neural circuits.” • Behavioral analysis tends to underestimate the occurrence of critical periods.
  • 24. Child Development, January/February 2011, Volume 82, Number 1, Pages 17–32 Science Does Not Speak for Itself: Translating Child Development Research for the Public and Its Policymakers Jack P. Shonkoff Susan Nall Bales Harvard University FrameWorks Institute “Science has an important role to play in advising policymakers on crafting effective responses to social problems that affect the development of children. This article describes lessons learned from a multiyear, working collaboration among neuroscientists, developmental psychologists, pediatricians, economists, and communications researchers who are engaged in the iterative construction of a core story of development, using simplifying models (i.e., metaphors) such as ‘‘brain architecture,’’ ‘‘toxic stress,’’ and ‘‘serve and return’’ to explain complex scientific concepts to nonscientists.”* *My italics.
  • 25. FrameWorks Institute • “The mission of the FrameWorks Institute is to advance the nonprofit sector's communications capacity by identifying, translating and modeling relevant scholarly research for framing the public discourse about social problems.” • “Understanding which frames serve to advance which policy options with which groups becomes central to any movement’s strategy. The literature of social movements suggests that the prudent choice of frames, and the ability to effectively contest the opposition’s frames, lie at the heart of successful policy advocacy.” http://www.frameworksinstitute.org/mission.html
  • 26. FrameWorks Original Simplifying Models In the course of harvesting research findings from FrameWorks’ work with the National Scientific Council on the Developing Child (now at Harvard University’s Center on the Developing Child), we recommended a set of “Simplifying Models” to help plug these cognitive holes: • Brain Architecture as a way to capture the material nature of the developmental foundation; • Interaction, as a way to elevate the dynamic process between child and environment; and • Stress-Related Chemicals in the Brain, as a way to make vivid the damaging effects of exposure to stress.
  • 27. Since this research was conducted for PCA America in 2003, FrameWorks has tested all three Simplifying Models in both qualitative and quantitative research and has improved the latter two models: Interaction has been updated to Serve and Return, in which the interactive nature of the child and his environment is equated with a game of tennis. Stress-Related Chemicals in the Brain has been expanded to differentiate between positive, tolerable and toxic stress in order to help people understand the buffering effects of caring adults and the deleterious effects of unrelieved exposure. http://www.frameworksinstitute.org/mission.html FrameWorks Revised Simplifying Models
  • 28. Science of Early Childhood Development Parenting Matters (2011), C. Paterson, Centre:Forum Both brain architecture and developing abilities are built “from the bottom up,” with simple circuits and skills providing the scaffolding for more advanced circuits and skills over time. Brain architecture and developing abilities are built from the bottom up over time. The interactive influences of genes and experience literally shape the architecture of the developing brain, and the active ingredient is the “serve and return” nature of children’s engagement in relationships with their parents and other caregivers in their family or community. The interactive influences of genes and experience shape the developing brain. (serve and return) Toxic stress in early childhood is associated with persistent effects on the nervous system and stress hormone systems that can damage developing brain architecture and lead to lifelong problems in learning, behavior, and both physical and mental health. Toxic stress damages developing brain architecture. Plasticity is maximal in early childhood and decreases with age The brain’s capacity for change decreases with age.
  • 29. Criticisms Raised in “The Myth” Still Apply • Equivocation on “early intervention” • Examples Perry Preschool Project and Abcedarian Project • Interventions prior to formal schooling enhance benefits of school attendance • Interventions are “early” because schooling starts early • Not evidence for biologically privileged sensitive period • Higher-level functions build on lower-level functions • Higher-level = later in development, lower-level = earlier? • “Skills beget skills”, but (most) skill learning is not developmentally constrained • Speed and ease of learning depends on prior experience, not necessarily early experience • Relations between synaptogenesis, pruning, and skill development remains unclear
  • 30. Experience-expectant vs Experience-dependent • Two kinds of brain plasticity (Greenough, Black & Wallace, 1987) • Experience-expectant • Limited to developing skills and neural systems that are characteristic of a species (E.g. vision, audition, first-language learning) • Stimulation required for normal development are reliably present in any typical species environment • Subject to critical or sensitive period constraints (loss of pre-existing synapses?) • Experience-dependent • Driven by experiences unique to the individuals and their particular physical, social and cultural environment • Allows us to learn from personal experience and store information to guide behavior • Not subject to critical or sensitive period constraints (formation of new synapses?)
  • 31. 37 MYTH - II There is only one sort of biological effect Wrong because there are at least 3 different varieties i. Experience-expectant effects (cf Hubel & Weisel expts on binocular vision & development of the visual cortex) Termed 'expectant' because in all ordinary circumstances the necessary experiences will always be available ii. Experience-adaptive effects (cf Barker hypothesis re long-term effects of restrictions in early growth) Unlike experience-expectant effects, these concern variations within, as well as outside, the normal range. Termed „adaptive‟ because the body is adapting to the nature of early experience iii. Experience-dependent effects (cf the adult experience examples) Unlike the first two varieties, these are not restricted to any kind of sensitive period restrictions epge.fgv.br/childhood/presentations/MICHAEL%20RUTTER.ppt
  • 32. Nature, Nurture, and Development: From Evangelism through Science toward Policy and Practice Michael Rutter, Child Development, January/February 2002, Volume 73, Number 1, Pages 1–21 “The last decade or so has been accompanied by a different type of evangelism—namely, claims on the extent to which early experiences determine brain development (see, e.g., Kotulak, 1996). There has been a misleading extrapolation of the findings on experience- expectant development to the entirely different notion that higher quality psychosocial experiences in the first 2 or 3 years of life will have a much greater effect than similar experiences later on, because the early experiences bring about a lasting change in brain structure.”
  • 33. Issues and Questions Early intervention 2014
  • 34. Neuroscientists also point to the importance of early parenting in the development of the infant brain.35 The prefrontal cortex, and specifically the orbitofrontal cortex, in the brain is thought to be especially important in emotional regulation, processing and expressing feelings, reading social cues and behaviour, and working memory, attention and decision making. Almost all of this area develops after birth. In the first year, a baby’s brain doubles in weight. Between six and twelve months in particular, there is a burst of brain development when attachment bonds are made.36 Research suggests that ‘toxic’ levels of stress – defined as ‘prolonged activation of stress response in the absence of protective relationships’ – can affect the infant’s developing brain.37 While the first years of brain development are not make-or-break, they have been found to affect the child’s ongoing brain development in important ways, shaping both their social-emotional, and cognitive development
  • 35. The foundations of brain architecture, and subsequent lifelong developmental potential, are laid down in a child’s early years through a process that is exquisitely sensitive to external influence. Early experiences in the home, in other care settings, and in communities interact with genes to shape the developing nature and quality of the brain’s architecture. The growth and then environmentally based pruning of neuronal systems in the first years support a range of early skills, including cognitive (early language, literacy, math), social (theory of mind, empathy, prosocial), persistence, attention, a nd self-regulation and executive function skills (the voluntary control of attention and behavior).2 Later skills— in schooling and employment—build cumulatively upon these early skills. Therefore investment in early learning and development is more efficient and can generate more benefits than costs relative to investment later in the life cycle.3
  • 36. Neuroscience as Background, Behavior as Ground • Both documents cite the neuroscience of child development in their opening paragraphs • No mention or citation of brain science thereafter • Policy debate on these issues will be about the validity and generalization of behavioral research – notoriously difficult • Neuroscience can eventually contribute only after behaviors and effects of interventions on behaviors are well-defined. • Neuroscience cannot yield reductive explanations of “non- phenomena.” • Neuroscience as background has rhetorical value only.
  • 37. Questions • Do we persist in extrapolating findings about experience-expectant plasticity to areas where these results are inapplicable? • Once we leave the realm of experience-expectant plasticity, what is normal? • Are we translating sound science to the public? • Is framing an appropriate mechanism by which to execute this translation? • What is the appropriate role of scientists, scholars, and academic institutions in this translation process? • If, and when, do the roles of scholar-scientist and advocate conflict? • What can be done to better integrate development psychology (study of normal development) with psychiatry (causes of psychopathology)?
  • 38. The Santiago Declaration www.SantiagoDeclaration.org We also recognize the limitations of our own scientific disciplines. Our research can provide guides in designing the most efficient means to a policy ends, but cannot dictate those ends, which must arise out of political debate and social consensus. Our research can also be abused in attempts to rationalize pre-conceived policies and popular notions about early childhood, putting science to a rhetorical and selective, rather than rational use.
  • 39. New Scientist January 11, 2014 Too late … The old man just doesn’t get it.
  • 40. 0 10 20 30 40 50 60 70 80 90 100 %MaxSynDensity Birth 1 yr. 11 yrs. From P. Huttenlocher 1987 Synaptic growth and pruning (visual and frontal cortex) 0 20 40 60 80 100 120 1 10 100 %MaxSynDen/LCRMGlc Log Years Huttenlocher/Chugani Data: Frontal Cortex MFG Syn Den Frontal LCMRGlc
  • 41. FIGURE 9 Examples of sensitive periods across four aspects of vision. Gray bars represent periods of normal development, and black bars represent sensitive periods for damage. Ages indicating the
  • 42. Oddity Task: Learning Curve 0 20 40 60 80 100 0 2 4 6 8 10 12 14 16 18 20 Age (yrs) %MaxGlucoseUptake 0 20 40 60 80 100 %MaxTrialstoCriterion % Max Glucose Uptake % Max.Trials to Criterion
  • 43. Critical periods Based on Hubel and Wiesel (1970) Normal Adults Deprivation During Critical Period Deprivation After Critical Period
  • 44. Enriched environments Turner and Greenough (1985) … a careful look does not support a selective focus on the 0-3 age range. … The work I and others have conducted on the effects of housing animals in physically and socially complex environments similarly emphasizes the continuing plasticity of the brain in later development and adulthood. William Greenough, APA Monitor, 1997
  • 45. • Fariña told committee members, “significant growth in speech, language, and brain development occurs before kindergarten.”
  • 46. Huttenlocher/Chugani Data: Frontal Cortex 0 20 40 60 80 100 0 2 4 6 8 10 12 14 16 18 Years %MaxSynDen/LCRMGlc MFG Syn Den Frontal LCMRGlc
  • 47. 0 10 20 30 40 50 60 70 80 90 100 %MaxSynDensity Birth 1 yr. 11 yrs. Redrawn from P. Huttenlocher 1987 Synaptic growth and pruning (visual cortex) Critical periods Enriched environments Based on Hubel and Wiesel (1970) Turner and Greenough (1985) 0 10 20 30 40 50 60 70 80 90 100 %MaxSynDensity Birth 1 yr. 11 yrs.
  • 48. Workers who have studied the development of the brain have found that to achieve the precision of the adult pattern, neural function is necessary: the brain must be stimulated in some fashion. Indeed, several observations during the last few decades have shown that babies who spent most of their first year of life lying their cribs develop abnormally slowly. Based in part on such observations, some people favor enriched environments for young children, in the hopes of enhancing development. Yet current studies provide no clear evidence that such extra stimulation is helpful. As a first step toward understanding the process, neurobiologists have focused on the development of the visual system … . Another physiological fact makes the visual system a productive object of study: its neurons are essentially the same as neurons in other parts of the brain. Carla Shatz: The Developing Brain (1992)
  • 49. Fade Out "Head Start has benefits for both 3-year-olds and 4-year-olds in the cognitive, health, and parenting domains, and for 3-year-olds in the social-emotional domain. However, the benefits of access to Head Start at age four are largely absent by 1st grade for the program population as a whole. For 3-year-olds, there are few sustained benefits, although access to the program may lead to improved parent-child relationships through 1st grade, a potentially important finding for children's longer term development.“ Weigel, Margaret (August 11, 2011). "Head Start Impact: Department of Health and Human Services Report".
  • 50. Brain-based Explanation for Fade-Out Children enter Head Start at age 3, after the critical first three years of brain development are over. Thus, the Head Start experiences occur too late in life to fundamentally and permanently rewire the children’s brains.
  • 51. 1st Wave (1994 – 2000): Strength of Claims • Strongly deterministic • “By the age of ten, your brain is cooked.” (Reiner) • Early experiences are so powerful …"they can completely change the way a person turns out.” (H. Chugani) • … "critical periods … are windows of opportunity that nature flings open, starting before birth, and then slams shut, one by one, with every additional candle on the child's birthday cake.” (Begley) • Critical periods in development • Narrow and rigid interpretation of critical periods • Closed by endogenous causes • Birth to three is the critical period for brain development
  • 52. 2nd Wave (2000 – 2011): Sources
  • 53. First and 2nd wave UK documents
  • 54. 3rd Wave (2010 – ) : Strength of Claims • Guarded Determinism • “Although ‘windows of opportunity’ for language and skill development and behavioural adaptation remain open for many years, trying to change behaviour or build new skills on a foundation of brain circuits that were not wired properly when they were first formed is much harder and requires more intensive effort.” • The brain’s capacity for change decreases with age. • Sensitive periods • The term ‘critical period’ does not appear. • “Brain architecture is built over a succession of ‘sensitive periods’, each of which is associated with the formation of specific circuits that are associated with specific abilities.”
  • 55. 3rd Wave (2010 – ): Power of metaphor  Relies on neuroscience to provide a materialistic/mechanistic explanation of learning, development, and mental illness.  However, language has become figurative: Metaphors are used to explain the implications of neuroscience to a lay audience.  Brain architecture  Serve and return  Toxic stress  Where did this metaphoric language come from?
  • 56. Cunha, Heckman et al. 2005
  • 57. A Lingering Neuromyth? The infant brain has more brain cells (neurons) and more connections (synapses) than the adult brain, and this means that it is more ‘plastic’, that is, more responsive to experience, including formal and informal instruction, than later on. As a consequence, learning new material appears to be easier earlier than later. -- Butterworth and Varma (2013) in Educational Neuroscience
  • 58. Do children learn more quickly and efficiently during the period of high synaptic density than after synaptic pruning occurs? Everything or certain kinds of things? Are the certain kinds of learning relevant to education, remediation, therapy?
  • 59. Also New Contributions from Academic scientists
  • 60. Summary and Issues • Strength of claims – from hard determinism to softer determinism • Language – literal but over-simplified to models and metaphors • Persistent themes • Materialist, mechanistic explanations throughout • Affinity for attachment theory and purported neural underpinnings • Underlying neuroscience carefully chosen • Not much advance in the neuroscientific bases for claims.
  • 61. Summary and Issues • Source • 1st wave: • from advocates outside the academy (with active assistance of some academic scientists) • Advocates oversimplifying science • 3rd wave: • from academy (with active assistance of experts on advocacy) • Scientists oversimplifying science
  • 62. Questions • To what extent is the brain early childhood campaign like and unlike other public health campaigns? (smoking, avian flu, immunization, breast feeding)? • Depth and strength of underlying science • Link between the science and proposed policy • Extent of social agreement on the policy end apart from the science • Is translation of science into policy an important academic endeavor in its own right? • Is “framing” an appropriate way to translate science for nonscientists? • When do the roles of scientist-scholar and advocate conflict? • If so what are the academic community’s responsibilities in conducting and reviewing such translations?