Literary Notices. 243 



Yale Psychological Studies, edited by Charles H. Judd: Monograph Supplement of The Psycho- 

 logical Review, Vol. VII, No. i, March, 1905, 226 pp. 



The first of these eight studies describes a new and ingenious means of photo- 

 graphing movements of the eye. A thin layer of Chinese white is treated on both 

 sides with paraffin, and then cut into small squares about I mm. across. Such a 

 square laid on the sclera just below and nasally from the cornea, keeps its place 

 on the eye-ball and is readily photographed. The merits of this method are that 

 the white fleck is so insignificant that it occasions no abnormalities in the move- 

 ments of the eye, and it gives a more easily interpretable record than a reflected 

 image from the cornea can give. The movements of such a reflected image are 

 unlike and very much less than the movements of the eye. So harmless is the 

 square of Chinese white that, a few seconds after application, the subject forgets 

 its presence. The eye-movements were photographed by a cinematographic 

 camera that could be operated at various speeds, the periods of closure and exposure 

 being equal. Each exposure, along with a time-curve, could be recorded on a drum. 

 An exposure of 60 o was usually found convenient. 



The following four papers by Prof. Judd, Dr. Cloyd N. McAllister, Mr. 

 E. H. Cameron, Mr. W. M. Steele, and Mr. Henry C. Courten, respectively, 

 give the results of a photographic study of eye-movements made during the con- 

 templation of simple figures and of three "geometrical-optical" illusions. There 

 seems to be no rigid fixation by the eye. "The image of a point fixated 

 may fall upon any point of a considerable area of the retina, around about, and 

 including the fovea centralis." In short the eye perpetually wobbles; and it is 

 only by chance that in successive instants of rest retinal elements once stimulated 

 are stimulated a second time. When the eye changes its fixation from one part 

 of the field of vision to another, the movement is seldom twice alike either in its 

 exact direction or in the number of intermediate pauses made. The movements 

 of the two eyes are only roughly coordinated; one eye, for instance, may pause 

 while the other moves on. The movements during attempted fixation reveal no 

 coordination. 



The movements made by the eye in surveying the illusions, are of less interest 

 in this place, particularly since their relation to the illusion as perceived is not yet 

 certain. The surprising incompleteness of the binocular coordination was shown 

 in all the experiments. 



The fifth paper studies unintentional movements made by the hand in reacting. 

 If a subject presses on a key and awaits a signal to release the same, he will often, 

 when the signal comes, press down still harder for a moment before he releases. 

 Mr. W. G. Smith has called this an "antagonistic reaction." By means of a 

 special reaction-key too complicated to be here described, the authors studied 

 both the up and down tensions of a finger while pressing on the key and reacting 

 to a signal. A preparatory warning signal was given, and both before and after 

 this a wavy line was usually traced by the finger. "In the wavy form we see a 

 rhythmical balance maintained between the tendency to react and its antagonistic." 

 In the "antagonistic reaction" nervous energy seems to be contributed to this 

 latter tendency that should be expended in the opposite direction — the release- 

 movement. This antagonistic reaction seems due entirely to the steady, down- 

 ward pressure excited previous to the reaction, for it largely disappears when a 

 gentle upward pressure preceded the final upward reaction. The antagonistic 



