An acronym for the Home Observation for Measurement of the Environment Inventory, originally devised by Bettye M. Caldwell and developed in collaboration with Robert H. Bradley at the University of Arkansas. It is designed to measure the quality and quantity of stimulation and support available to a child in the home environment from infancy through …
Category Archives: Uncategorized
Homeodomain proteins and homeobox genes
Proteins encoded by homeobox genes that are involved in the control of gene expression during morphogenesis and development. A homeobox is a short DNA sequence of about 180 base pairs. Its genes encode protein and bind and regulate the expression of DNA is multicellular organisms. They are present in the genomes of organisms ranging from …
Holism
A term accredited to Jan C. Smuts (1870-1950) who first used it in the 1920s as the antithesis of radical reductionism, and which is understood to mean that the properties of a system cannot be determined or explained by the sum of its constituent parts alone. Accordingly, systems are hierarchically organized, with the emergence of …
Holoprosencephaly
Congenital brainmalformation occurring during embryonic development in which the two halves of the prosencephalon or forebrain fail todivide properly into left and right hemispheres, the outcome being a single-lobed brain . Four types include alobar (no hemispheric division usually associated with severe facial defects, e.g., cyclopia, a single eye, and stillbirth), semi-lobar (some hemispheric division and intermediate …
Hodology
Used in many different disciplines (e.g., computer science, geography, town planning), but not found in the Oxford english dictionary, it is derived from the Greek word hodos meaning a ‘way’, and in general can be defined as the science of studying pathways between structures. In the present instance, it refers to pathways between neuroanatomical structures …
Histone
Not occurring in vertebrate sperm cells or bacteria, they are any group of water-soluble proteins found in conjunction with the DNA of chromosomes. Containing major parts of the basic amino acids argentine, histamine, lysine, they are thought to be involved in the condensation and coiling of chromosomes during cell division. They may also be involved …
Hixon symposium
A meeting on brain-behavior relationships held at Caltech in September 1948 and attended by psychologists and what we now know as computer scientists, network modellers and neuroscientists (see photograph below). At the meeting, for example, John von Neumann (1903-1957), circled in red, presented his theory of automata and Karl S. Lashley (1890-1958), circled in blue, …
Histology
The branch of anatomy that studies the structure and function of cells and tissue at the microscopical level. The four major tissues that make up the bodies of animals are epithelial, nervous, muscle and connective tissue. See Cell, Epithelium, Mesenchyne
Hierarchy
The arrangement of items and or sub-items by size or other criteria such as relative control; can be applied to actions, underlying operations, and social relationships. Abraham Maslow (1908-1970) was responsible for perhaps the most widely known application of the hierarchy concept with his hierarchy of needs model, first published as a paper in 1943, …
Hippocampus
A forebrain structure of the temporal lobe, shaped like a seahorse (see figure below), and part of the limbic system, it is thought to be important in emotion, motivation, spatial abilities (e.g., ‘navigation by cognitive maps’) and the consolidation of declarative (but not procedural) memory. Damage to the hippocampus is consistently associated with significant loss …