Debriefing

A procedure implemented after research participation has ended, and designed to explain to participants the nature and purpose of the research in detail (including any deception), and to check on their well-being, offer reassurance and answer their queries etc.  While national psychological associations and societies, as well as other professional bodies, strongly recommend debriefing in …

Declarative (or explicit) and procedural memory

Both are classes of long-term memory.  Declarative memory is the portion of long-term memory where information about facts and specific events is stored, involves structures in the temporal lobe (especially the hippocampus), and which is distinguished in terms of episodic and semantic memory.  Procedural memory, which is governed by different brain systems, is a storage …

De Morsier-Kallmann syndrome

A spectrum of rare (1 in 10.000, male/femaleratio 5/1) congenital disorders caused by failure of the hypothalamus to release the  gonadotropin hormone (GnRH) during embryonic brain differentiation.  Afflicted patients evinceabsent or incomplete puberty, and somatic and reproductive problems associatedwith hypogonadism.  In addition to hypogonadism, there may be a loss or reduced sense of smell (hence …

Darwinism

Darwin’s theory of natural selection of small, inherited variations that increase an individual’s ability to compete for resources, survive and reproduce.  The problems for Darwin were how such genetic variations arose and how they were transmitted from one generation to the next.  The answer to the first problem was random mutation, with chromosomal rearrangement and …

Dandy Walker malformation

A structuraldevelopmental abnormality occurring during embryonic development in which the cerebellar vermis has not developedappropriately (partially or completely absent) and there is dilatation of the fourth ventricle.  As with Chiari II malformation, it is frequently associated with agenesis of the corpus callosum, and also hydrocephalus (20-80% of cases).  Infants with the malformation can manifest delayed …

Cytoskeleton

The internal framework (or ‘scaffolding’) of a cell within the cytoplasm, composed largely of actin filaments and microtubules (see figure below).  In eukaryotic cells, actin filaments (or microfilaments) are active in muscle contraction, intermediate filaments hold microfilaments and microtubules in place, and microtubules serve as routes for organelles to move along.  In general, the cytoskeleton …

Décalage

From the French for ‘time lag’, the Piagetian idea that cognitive abilities develop at different rates in the same individual. For example, children solve conservation of number tasks before they solve conservation of mass tasks and the latter before they can conserve weight, a phenomenon termed horizontal décalage (i.e., the inability of a child to …

Cytosine

A pyrimidine base found in DNA and RNA, as well as nucleotides and their derivatives.  It always bonds with the purine guanine. See DNA (deoxyribonucleic acid), Guanine, Methylation, Nucleotide, Purines, Pyrimidines, RNA (ribonucleic acid)