fixaation

Fixation is the act of fixing something in place or the state of being fixed. In science and medicine, it covers several distinct meanings that share the general idea of stabilization, preservation, or conversion to a fixed state.

Biology and medicine: Tissue fixation preserves biological samples for microscopy. Common fixatives include formaldehyde and glutaraldehyde; fixation preserves structure by crosslinking proteins and other molecules. In orthopedics, fixation describes methods to immobilize a bone or fracture to promote healing, using internal devices such as plates and screws or external frames.

Chemistry and ecology: Carbon fixation is the conversion of inorganic carbon dioxide into organic compounds, a central process of photosynthesis and other biosynthetic routes. Nitrogen fixation refers to the conversion of atmospheric nitrogen into ammonia or related compounds, carried out by certain bacteria and by industrial processes.

Psychology and cognitive science: In psychoanalysis, fixation denotes a persistent focus on an earlier psychosexual stage or drive that shapes behavior. In contemporary psychology, fixation can also describe attentional binding where a person fixates on a stimulus, as seen in eye-tracking studies; fixations are moments where the gaze remains on a location before moving on via a saccade.

In sum, fixation is a multidisciplinary concept with contexts ranging from preserving specimens to securing bones, from chemical transformations to patterns of attention and development.