450 



SCIENCE 



[N. S. Vol. LI. No. 1323 



(The subject was required to encipher a num- 

 ber of sets of nonsense-material into specially 

 prepared codes, both the material and the 

 ciphers being selected for tmiformity in the 

 distribution of difficulties.) Some interesting 

 records were obtained, which, however, do not 

 give the quantitative measure of impairment 

 which the appearance of the graphs suggests. 

 One reason for this fact is that many sub- 

 jects tend to compensate for impairment of 

 response by an increase of " voluntary " 

 effort. The fact can be noted by the observer, 

 and such clinical notes are necessary to cor- 

 rect interpretation of the " quantitative " data. 



Some tests on the fluctuations of visual 

 acuity over extended periods of observation 

 were made by the wi-iter, using in general the 

 method described by Cobb;^ the test-field, 

 however being a real image of the pattern of 

 the Ives-Cobb visual acuity test-object, slightly 

 magnified on one half and slightly reduced on 

 the other, projected into the plane of an open- 

 ing in a screen 60 cm. from the eye. Some 

 results thus obtained were not fully expected; 

 e. g., (1) it appeared that fixation and accom- 

 modation upon a stationary object can be 

 maintained until the last stages of asphyxi- 

 ation have been reached; (2) that disturbance 

 of the visual function is not exhibited by this 

 type of test until the more highly coordinated 

 processes have actually begun to fail; and (3) 

 that in the last stages of asphyxiation, visual 

 impressions may become intermittent and the 

 entire field become darkened, without the out- 

 lines of objects appearing blurred, and with- 

 out diplopia developing under the conditions 

 of this particular test. It should be re- 

 marked, however, that these conditions are 

 much less trying than those which compel 

 coordinated eye-movements to be executed 

 within a limited time; and that the latter 

 conditions often elicit and exhibit marked 

 disturbances. This work will probably be 

 carried farther. 



Dr. Rogers perfected an attachment for the 

 Henderson rebreather by means of which the 



1 Cobb, P. W., ' ' The Influence of PupiiUary 

 Diameter on Visual Acuity, ' ' Am. Jour. Physiol., 

 1915, Vol. XXXVI., pp. 335-346. 



rate of diminution of oxygen can be con- 

 trolled, within reasonable limits, through the 

 replacement of a known proportion of the 

 oxygen consumed within a given time. The 

 apparatus is considered superior in some re- 

 spects to one previously used in another de- 

 partment, and its employment assures that 

 different subjects can be made to experience 

 comparable degrees of oxygen-hunger for com- 

 parable times. 



An investigation was made by Dr. Mc- 

 Comas on the influence of diminished air- 

 pressure, simulating an altitude of 20,000 

 feet, on the time required for selective re- 

 action to a number of combinations of signals 

 visually perceived. The experiment being ex- 

 ploratory in character, and the time of the 

 experimenter being limited, it was not feasible 

 to introduce certain controls which otherwise 

 would have been desirable. However, the data 

 as obtained indicate that the time required 

 for selective response is greatly lengthened 

 and its variability increased, by the abnormal 

 conditions of the experiment, until the sub- 

 ject by continued practise has rendered his 

 responses almost purely mechanical. The re- 

 sults obtained in the later stages of training 

 are open to more than one interpretation, and 

 it is planned to resume experimentation as 

 soon as may be practicable. 



Dr. Bagby made a systematic contribution 

 in the form of a study entitled "A psycho- 

 logical point of view in psychiatry, with 

 special reference to pathological behavior 

 under deprivation of oxygen." This report 

 calls attention to manifestations of emotional 

 instability which sometimes occur during the 

 rebreathing test in the absence of adequate 

 external stimuli. The display under such 

 conditions of anger, fear, destructiveness, ex- 

 cessive nonchalance, silliness and euphoria, is 

 compared with symptoms of alcoholic intoxi- 

 cation, and with characteristic symptoms of 

 certain types of insanity. The opportunity 

 incidentally afforded by the test, of observing 

 evidences of lack of poise which are not nec- 

 essarily prominent in the normal state, is 

 emphasized. 



A study of associative responses was begun 



