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Cognitive Development. David F. Bjorklund. Some Basic Concepts in Cognitive Development. Cognition :
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Cognitive Development David F. Bjorklund
Some Basic Concepts in Cognitive Development • Cognition: The processes or faculties by which knowledge is acquired and manipulated. Cognition is usually thought of as being mental. That is, cognition is a reflection of a mind. It is not directly observable but must be inferred. • Development: Changes in structure or function over time.
Structurerefers to some substrate of the organism, such as nervous tissue, muscle, or limbs, or—in cognitive psychology—the mental knowledge that underlies intelligence. • Function denotes actions related to a structure and can include actions external to the structure being studied, such as neurochemical or hormonal secretions, and other exogenous factors that can best be described as “experience”—that is, external sources of stimulation. • Development is characteristic of the species and has its basis in biology. Its general course, therefore, is relatively predictable. Development progresses as a result of bidirectional, or reciprocal, relationship between structure and function, and can be expressed as structure function.
Developmental function The species-typical form that cognition takes over time. • Individual differences: Differences in patterns of intellectual aptitudes among people of a given age.
Issues in Cognitive Development • Nature versus nurture, or more properly, how do genes/biology and environment interact to yield the adult phenotype. • Stages of Development • How Does Cognitive Change Occur? Dynamic Systems Approaches to Development • Domain-General versus Domain-Specific Abilities • Stability and Plasticity of Intelligence • Changes in Representation • Changes in Intentional Control
Nature versus nurture, or more properly, how do genes/biology and environment interact to yield the adult phenotype.
Framing the Nature/Nurture Issue • Nature: heredity (nativism) • Maturational processes guided by genes • Biologically based predispositions • Biological unfolding of genes • Genetic determinism • Nurture: environment (empiricism) • Learning: experiences cause changes is thoughts, feelings, and behaviors • Environmental determinism • Interactionist view: nature & nurture interact
Caspi et al., 2002 • monoamine oxidase A (MAOA) associated with antisocial behavior in rats and humans • Gene on X chromosome controls MAOA (high versus low levels) • Examined antisocial behavior in boys with high and low levels of MAOA as function of childhood maltreatment
Relationship between childhood maltreatment (none, probable, severe) and MAOA activity (low versus high) on antisocial behavior.
What Does it Mean to Say Something is “Innate”? • Representational constraints (or representational innateness) Representations that are hardwired into the brain so that some types of “knowledge” are innate. • Knowledge of objects • Universal grammar • Architectural constraints (or architectural innateness) Ways in which the architecture of the brain is organized at birth, thus limiting the way information can be processed and understood. Inhibitory versus excitatory neurons Global organization (what’s connected to what) • Chronotopic constraints (or chronotopic innateness) Limitations on the developmental timing of events, affecting what can be acquired when. Critical (sensitive) periods
Some cognitive abilities, such as language, might be most easily acquired during a critical period in development
Stages of Development • Continuity versus Discontinuity • Quantitative versus Qualitative Differences • Homogeneity of Cognitive Function
Dynamic Systems Approaches to Development • “Patterns and order emerge from interactions of the components of complex systems without explicit instruction either in the organism itself or from the environment” (Thelen & Smith, 1998, p. 564) • Self-organization • Phase transitions • Nonlinear • Relatively abrupt
Matrix problem (Siegler & Svetina, 2002) • Analogical reasoning problem with 6- to 8-year olds, with objects varying in form, size, orientation, & color • Light-colored, large, right-facing mouse is to a light-colored, large, right-facing bird as a light-colored, small, left-facing mouse is to: • Light-colored, small,left-facing bird (correct choice) • Light-colored, small, left-facing mouse (duplicate error) • Light-colored, small, right-facing bird • Light-colored, large, left-facing bird • Dark-colored, small, left-facing bird • Dark-colored rabbit
Pattern of changes on matrix problem (Siegler & Svetina, 2002)
The Stability and Plasticity of Human Behavior • Stability refers to the degree to which people maintain their same rank order in comparison to other children with respect to some characteristic • Plasticity refers to the ability to change as a result of experience.
Basic tenet of evolutionary psychology: • The human mind has been prepared by natural selection, operating over geological time, for life in a human group.
Some Assumptions of Evolutionary Psychology • What evolved are psychological mechanisms (information processing mechanisms are the “missing link” in evolutionary explication) • Information processing are relatively independent domain-specific modules designed to solve recurrent problems faced by our ancestors • Psychological mechanisms evolved in the “environment of evolutionary adaptedness” • An emphasis on adaptationist thinking, which stresses the function of a behavior or trait • Evolution occurs via mechanisms described by the Modern Synthesis, with special emphasis on the role of natural selection as proposed by Darwin
Basic Tenets of Natural Selection (from Darwin, 1859): • Superfecundity • Variationtion is characteristic among members of a species • Variation is heritable • Characteristics that result in individuals surviving and reproducing tend to be selected as a result of the interaction between the individual and the environment
Predicted Developmental Features of Evolved Cognitive Modules • Hierarchical in Nature • Sensitive Periods and Child-Initiated Activity • Based on Implicit Knowledge • Observed Universally • Universal Developmental Ontogeny
Biologically primary vs. biologically secondary abilities • Biologically primary abilities: Cognitive abilities selected in evolution. • Acquire universally • Universal developmental course • Children have high motivation to perform them • Biologically secondary abilities: Cognitive abilities built on primary abilities that are culturally determined. • Not universal • Tedious repetition and external pressure often needed for their mastery
Models of Gene-Environment Interaction in Cognitive Development
Developmental Systems Approach • Development proceeds as a result of the bidirectional interaction between structure and function over time at all levels of organization, from the genetic through the cultural. • Epigenesis: “any gene-regulating activity that doesn’t involve changes to the DNA code and that can persist through one or more generations” (Pennisi, 2001) Genetic activity (DNA <-> RNA <-> proteins) <-> structural maturation <-> function, activity
A simplified schematic of the developmental systems approach, showing a hierarchy of four mutually interacting components (from Gottlieb)
Ducklings still in egg that are afforded sound of mother, brood mates, or self-vocalizations will approach maternal conspecific call hours after hatching. • Ducklings denied any species-typical acoustic experience shows no preference • Previously described “instinctive” (i.e., no previous experience necessary) behavior is critically dependent upon species-typical experience for its expression
Premature Visual Stimulation and Subsequent Acoustic “imprinting” (Lickliter, 1990) • Bobwhite quails had part of shell removed 2-3 days before hatching • Experimental group: pattern light • Control group: no patterned light • Auditory preference test: • Bobwhite quail maternal call • Chicken call • No preference
Percentage of bobwhite quail chicks that approached the bobwhite quail maternal call, the chicken call, or showed no preference as a function of premature visual exposure (Lickliter, 1990)
Discrimination learning set performance for monkeys as a function of the age at which testing was begun (from Harlow, 1959)
“There is a tendency to think of learning or training as intrinsically good and necessarily valuable to the organism. It is entirely possible, however, that training can be either helpful or harmful,depending upon the nature of the training and the organism’s stage of development (Harlow, 1959, p. 472).
Age at which infants reached the criterion as a function of when training was begun (from Papousek, 1977)
“Social contexts evolved in the course of human phylogeny are surprisingly fine-tuned in specificity to provide good-enough environments for the human cortex to unfold, initially intrauterinely, then extrautaurterinely. . . With advances in medical technology, that is, material culture, even very immature nervous systems exist and develop outside the womb. However, the social context of traditional special care nurseries bring with them less than adequate support for immature nervous systems . . . Leading to maladaptations and disabilities, yet also to accelerations and extraordinary abilities (Als, 1995, p. 462)
Three types of genotype -> environment effects • Passive Biological parents provide both genes and environment for child. Passive effects decrease with age • Evocative Temperamental characteristics of child evokes responses from others. Evocative effects remain constant with age, • Active Children seek out environments consistent with their genotype Active effects increase with age.
Changes in correlations of IQ between siblings at different times • Correlation of IQs of adopted siblings (from Scarr & Weinberg, 1978) in childhood: range between .25 - .39 • Correlation of IQs of dizygotic (nonidentical) twins (from Mathney et al., 1981): range between .60 - .75 • Correlation of IQs of adopted siblings (from Scarr & Weinberg, 1978) in adolescence: .00 • Correlation of IQs of dizygotic (nonidentical) twins (from Mathney et al., 1981) in adolescence: .55
“Good enough” parents “ordinary differences between families have little effect on children’s development, unless the family is outside of a normal developmental range. Good enough,ordinary parents probably have the same effects on their children’s development as culturally defined superparents” (Scarr, 1992, p. 15)
Resilient children • Children who develop social and intellectual competence despite growing up in impoverished “high-risk” environments • “Through the process of evolution, parenting has been shaped to protect development; nature has created in ordinary parents a powerful protective system for child development (Masten & Coatsworth, 1998, p. 213)
Neuronal Development(neurogenesis) • Proliferation • Migration • Differentiation • Synaptogenesis • Selective Cell Death
The Role of Experience in Brain Development • Experience-expectant processes (experience-expectant synaptogenesis) (Greenough et al.) • Experience-dependent processes (experience-dependent synaptogenesis) • Neural Darwinism (Edleman)
Brain Plasticity • Neuronal plasticity • Recovery of function from brain damage • Slow growth and plasticity
Sociocultural Perspectives on Cognitive Development • “Cognitive development is an active constructive process that involves beings who are evolutionarily predisposed to live and learn in social context with other ‘like-minded’ beings. They are like-minded in terms of both the neurological system available and the social requirements that are in place” • Mary Gauvain, 2001
Lev Vygotsky • Development should be evaluated from the perspective of four inter-related levels: • Phylogenetic • Ontogenetic • Microgenetic • Sociohistorical
Tools of Intellectual adaptation • Methods of thinking and problem-solving strategies that children internalize from their interactions with more competent members of society that permit them to use basic mental functions more adaptively
Chinese and English number words from 1 to 20 • Number Chinese word English word • 1 yee one • 2 uhr two • 3 sahn three • 4 suh four • 5 woo five • 6 lyo six • 7 chee seven • 8 bah eight • 9 jyo nine • 10 shi ten • 11 shi yee eleven • 12 shi uhr twelve • 13 shi shan thirteen • 14 shi suh fourteen • 15 shi woo fifteen • 16 shi lyo sixteen • 17 shi chee seventeen • 18 shi bah eighteen • 19 shi jyo nineteen • 20 ershi twenty