Orienting response

The orienting response (OR), also called orienting reflex, is an organism's immediate response to a change in its environment, when that change is not sudden enough to elicit the startle reflex. The phenomenon was first described by Russian physiologist Ivan Sechenov in his 1863 book Reflexes of the Brain, and the term ('ориентировочный рефлекс' in Russian) was coined by Ivan Pavlov, who also referred to it as the Shto takoye? (Что такое? or What is it?) reflex. The orienting response is a reaction to novel or significant stimuli. In the 1950s the orienting response was studied systematically by the Russian scientist Evgeny Sokolov, who documented the phenomenon called "habituation", referring to a gradual "familiarity effect" and reduction of the orienting response with repeated stimulus presentations.[1]

Researchers have found a number of physiological mechanisms associated with OR, including changes in phasic and tonic skin conductance response (SCR), electroencephalogram (EEG), and heart rate following a novel or significant stimulus. These observations all occur within seconds of stimulus introduction.[2] In particular, EEG studies of OR have corresponded particularly with the P300 wave and P3a component of the OR-related event-related potential (ERP).[3]

  1. ^ Sokolov, E.N, Neuronal models and the orienting reflex, in The Central Nervous System and Behavior, Mary A.B. Brazier, ed. NY: JosiahMacy, Jr. Foundation, 1960, pp. 187–276
  2. ^ Bradley, Margaret M. (January 2009). "Natural selective attention: Orienting and emotion". Psychophysiology. 46 (1): 1–11. doi:10.1111/j.1469-8986.2008.00702.x. PMC 3645482. PMID 18778317.
  3. ^ Polich, J. (2003). Overview of P3a and P3b. In J. Polich (Ed.), Detection of Change:Event-Related Potential and fMRI Findings (pp. 83-98). Kluwer Academic Press: Boston.