Blocking in mental fatigue and anoxemia compared.

Aviation.

“…The flight factors studied have been: low barometric pressure (17, 41), decreased partial pressure of oxygen (1,2,8,16,28,35,44,52,53,66,80,87), acceleration and centrifugal force (7,18,41,47,57,88,89), vibration (14), temperature (60), as well as such variables as humidity, noise, and light, including ultraviolet and glare (4,60,73). The physiological and simple sensory and motor effects investigated (in the main, deleterious) have included changes in circulation (14,17,18,34,66), respiration and metabolism (16,28), vision (14,18,53,85,86,88), audition (35,60), tac- 1 These titles have been selected and abstracted by Razran and are being indexed and prepared for publication under the diiection of Brown.…”

“…tion (14), kinesthesis (68), static sense 2 (7,57,63), reflexes (14,87), muscle tension (2,87), muscular strength (34,68,80), and reaction time (14,68,80,87). The psychological and more complex functions affected (again, deleteriously) have come under the headings of attention (68), concentration (68,87), memory span and mental arithmetic (68,80,87), color-naming (8), card-sorting (80), writing (44,68,80), manual-work performance (68), affectivity (87), and various test performances (14). Schubert (73) has thoroughly reviewed the physiological factors.…”

“…); simulated flight through such devices as low-pressure chambers (1, 34, 35, etc. ), barochambers (17), nitrogen dilution (8,53), and various rebreather devices (2, 92, etc. ); and mechanical oscillator (14).…”

Effect of benzedrine sulphate on blocking in color naming.

“…Occurrence of blocking in this and other simple responses has been studied by Bills (1,2,3,4) who reports that the following principles apply to the phenomena: Bills suggests that blocking is related to the neurological phenomenon of the cumulative refractory phase and Telford (19) has discovered characteristics in associative responses that show much evidence of obeying the laws of the refractory phases. As it seems quite evident that blocking is dependent to a great extent upon the physiological state of the organism, we may expect it to be affected by a changed physiological state.…”

Studying motor functions and efficiency.

“…(From an unpublished study by Geldreich and Bills.) which arise in this field is the study made by Bills [4] of the effects of reduction in the oxygen content of inspired air on efficiency in the task of serial color discrimination. The method used was to prepare a large supply of air of a given desired oxygen content, before each experimental period, by mixing air with nitrogen in a chamber in the appropriate amounts.…”