Week 9: Physical and Perceptual Development

Comprehensive vocabulary flashcards covering the biological, physical, neurological, and perceptual development principles discussed throughout the lecture.

Orthogenetic principle

A developmental pattern where physical and motor growth begins in a global, undifferentiated state and progressively becomes more hierarchical, differentiated, and integrated.

Cephalocaudal principle

The 'head-to-tail' pattern of growth and motor development, where control over the head and facial structures develops before the arms and torso, followed finally by the legs and feet.

Proximodistal principle

The centre-outward direction of motor and physical development, wherein central structures such as the spine develop before peripheral limbs, and gross trunk control precedes fine finger dexterity.

Secular trend

A historical pattern observed in industrialized societies toward earlier physical maturation and larger average adult body size across successive generations.

Life History Theory

An evolutionary framework proposing that organisms allocate finite bioenergetic resources across competing demands, specifically growth, somatic maintenance, reproduction, and parental investment.

Fast life history strategy

A developmental trajectory characterized by accelerated physical and sexual maturation, earlier reproduction, short-term planning, and an emphasis on immediate rewards, adaptive in unstable, unpredictable, or high-mortality environments.

Slow life history strategy

A developmental trajectory characterized by protracted maturation, delayed reproduction, long-term planning, and high parental investment, adaptive in safe, predictable, and resource-rich environments.

Match-Mismatch Hypothesis

The developmental principle stating that early-life phenotypic adaptations may prove adaptive or maladaptive depending on the degree of concordance between early-life environments and later adult environments.

Menopause

The permanent cessation of menstrual cycles occurring at an average age of $51$ years in human females, characterized by a sharp drop in circulating ovarian estrogen synthesis.

Grandmother Hypothesis

An evolutionary model suggesting natural selection favored an extended post-reproductive female lifespan because grandmothers enhance descendant survival and shorten maternal interbirth intervals by gathering food and assisting with childcare.

Inclusive fitness

An individual's total genetic representation in subsequent generations, calculated as the sum of direct personal reproductive output and indirect reproductive success achieved by promoting the survival and reproduction of genetic kin.

Osteoporosis

A progressive skeletal disorder marked by reduced bone mineral density and bone deterioration, which sharply elevates fracture risk and affects roughly $25\%$ of women and $6\%$ of men aged $65$ years and older.

Life-course approach to musculoskeletal health

The model proposing that early-life plasticity provides critical periods to build peak bone and muscle reserves through nutrition and exercise, determining the trajectory of functional musculoskeletal decline in older age.

Neurogenesis

The biological process responsible for the generation and formation of new neurons in the central nervous system.

Synaptogenesis

The developmental formation of functional synapses or connections between neurons in the nervous system.

Synaptic pruning

The selective elimination of weak, excess, or underutilized synaptic connections, refining neural circuitry to optimize signaling efficiency and brain organization.

Grey matter

Neural tissue containing unmyelinated neuronal cell bodies, dendrites, and synapses that forms the cerebral cortex and acts as the primary site of information processing.

White matter

Nerve tissue located primarily beneath the cortex composed of bundles of myelinated axons responsible for transmitting signals between distant brain regions.

Brain lateralization

The structural asymmetry and functional specialization of the cerebral hemispheres, wherein the left hemisphere preferentially governs sequential, analytic, and linguistic operations, while the right hemisphere governs simultaneous, holistic, visuospatial, and creative processing.

Approach motivation

The energized drive or behavioral impulse directed toward initiating engagement with, moving toward, or securing desired appetitive stimuli and rewarding outcomes.

Avoidance motivation

The behavioral impulse aimed at withdrawing from, escaping, or defending against aversive conditions, potential penalties, or threatening stimuli.

Sword and Shield Hypothesis

The hypothesis proposed by Brookshire and Casasanto ($2012$) stating that the hemispheric lateralization of approach motivation mirrors the motor dominance of the dominant hand ('sword') rather than remaining invariant across individuals.

Dynamic Systems Theory (Motor Development)

Esther Thelen and Linda Smith's framework stating that motor behaviors are self-organizing and nonlinear, emerging from continuous real-time interactions among bodily, neurological, perceptual, and environmental constraints.

Equifinality

A dynamic systems principle asserting that identical developmental outcomes or functional skills can be reached via diverse paths and distinct subsystem combinations.

Rhythmic stereotypes

Repetitive, stereotyped gross motor movements (such as rhythmic leg kicking, body rocking, or arm banging) displayed spontaneously prior to the onset of skilled voluntary locomotion.

Sensation

The initial physical detection and raw discrimination of external environmental energy by specialized sensory receptors.

Perception

The cognitive processing, interpretation, recognition, and categorization of incoming sensory information to produce meaningful conscious experience.

Differentiation Theory

The perceptual perspective developed by Eleanor and James Gibson proposing that perception involves active exploration to detect invariant features, affordances, and stable properties across dynamic sensory arrays.

Affordances

The actionable properties and interaction opportunities provided by an object or environmental layout relative to the specific physical capabilities of an organism.

Perceptual-motor coupling

The bidirectional coordination between perception and bodily actions, where motor engagement yields perceptual feedback, and perception guides appropriate motor responses.

Preferential looking technique

A behavioral testing procedure used to assess infant sensory discrimination by presenting two stimuli side-by-side and quantifying disparities in visual fixation duration.

Habituation

A progressive reduction in the magnitude, frequency, or duration of an innate behavioral or physiological orienting response following repeated exposure to a non-varying stimulus.

Dishabituation

The rapid recovery of an orienting or exploratory response when an organism detects a novel, distinct stimulus following prior habituation.

Evoked potentials

Recordings of scalp electrical activity that capture precise time-locked neurophysiological responses elicited by sensory inputs such as auditory clicks, flashes, or odors.

Visual acuity

The resolving capacity of the visual system to distinguish fine spatial patterns and sharp visual details at a specified distance.

Snellen chart

A clinical optical chart used to evaluate visual acuity, where the top number represents viewing distance ($20\text{ feet}$) and the bottom number denotes the distance from which a standard eye resolves those letters.

Size constancy

The perceptual capacity to recognize that an object's physical dimensions remain invariant despite distance-dependent shifts in its projected retinal image size.

Shape constancy

The perceptual recognition that an object's intrinsic three-dimensional geometric structure remains unchanged regardless of variations in its viewing angle or retinal projection.

Stereopsis

The neural computation of depth and three-dimensional spatial coordinates resulting from the binocular integration of disparate retinal inputs from each eye.

Visual cliff

An experimental apparatus developed by Gibson and Walk ($1960$) featuring an elevated sheet of heavy glass extending over an apparent shallow drop-off on one side and a deep drop-off on the other to test depth perception across species.

Cross-modal perception

The cognitive capability to combine, synchronize, and recognize perceptual information gathered simultaneously or sequentially across two or more separate sensory channels.

Perceptual learning

Relatively permanent enhancements in the accuracy, speed, or sensitivity of sensory performance achieved through structured training, active practice, or repetitive exposure.

Perceptual expertise

Advanced perceptual skill accumulated through extended real-world domain practice, enabling specialists (e.g., master chess players or radiologists) to rapidly process and interpret complex configurations.

Signal-to-noise ratio

A quantitative metric contrasting the magnitude of meaningful, task-relevant informational signals against the magnitude of background neural or environmental noise.

Representation Enhancement Theory

A mechanistic theory stating that visual perceptual learning enhances performance by directly modifying and sharpening the neuronal receptive fields and stimulus representations in early visual cortical structures.

Information Reweighting Theory

A mechanistic theory stating that visual perceptual learning operates by dynamically up-weighting task-relevant early sensory inputs and down-weighting irrelevant sensory noise during decision stages, leaving early cortical representations unmodified.