SECTIONAL TRANSACTIONS.— I, J. 399 



15. Mr. F. Haynes. — Changes in the Lungs of Pit-ponies. (Demonstra- 



tion.) 



1 6. Dr. W. A. AiKiN. — The Application of Normal Physiology to Speaking 



and Singing. 



1 7. Miss S. Cooper and Mr. D. Denny-Brown.— fies^jonses to Stimulation 



of the Cerebral Cortex. 



18. Dr. J. S. Haldane, F.R.S. — Lecture on Acclimatisation to High 



Altitudes. 



SECTION J.— PSYCHOLOGY. 



Thursday, August 5. 



^For references to the publication elsewhere of communications entered in the 

 following list of Transactions, see page 448.) 



1. Prof. C. Spearman, ¥. U.S.— The Origin of Error. 



2. Prof. A. Michotte. — Observation and Analysis of Mental Facts. 



3. Dr. F. AvELiNG. — Brief Notes on the Psychogalvanic Phenomenon so 



far as this is relevant to Psychology. 



Correlation of the P.G.R. with Mental Process ; Physiological Process involved ; 

 Ascertained Psychological and Physiological Sequences ; Difficulties in the way of 

 scientific handling of the facts ; Distinction of Mental Process as Cognitive and 

 Appetitive ; Further Distinction of Orectic Process as Conative and Affective ; 

 Relation of the P.G. Phenomenon to Conative Process ; The James-Lange Theory ; 

 Objections of Wechsler to the Conative Significance of the P.G.R. ; The Concept of 

 the Unconscious ; Ambiguity of Terms ; General Evidence from Researches ; Further 

 Evidence from a Research on Conation and Volition ; Theoretical Conclusions of 

 Importance Indicated ; Data of ' Brief Notes ' submitted for Discussion. 



4. Dr. Marguerite E. Bickersteth. — Colour Imagery. 



5. Prof. W. McDoUGALL, F.R.S. — Intelligence in Rats. 



6. Dr. H. Banister. — A new Hypothesis of the Localisation of Sound. 



Two factors appear to be at the basis of sound localisation, viz., time-diSerence at 

 the ears for short sounds (clicks), and for continuous sounds of low pitch, and 

 intensity differences for sounds of high pitch. To explain these we must turn to the 

 physiology of the sensory elements. 



It seems probable that nervous impulses in the auditory nerve are discrete. They 

 are initiated by the movements of the cilia of the hair-cells on the Basilar Membrane. 

 Assuming that the impulses are initiated when the cilia are in a certain phase of their 

 cycle, the impulses from the two ears will reach their respective sensor}- areas in the 

 brain at time-differences equal to those between the arrival of the sound-waves at the 

 ears. This gives locaUsation by time-difference. Now nervous impulses cannot 

 follow one another along a nerve at time-intervals less than the Refractory Period. 

 If the ciHa are in the position for initiating an impulse during the Refractory Period, 

 that impulse will not be initiated. For these frequencies localisation by time- 

 difference will be ambiguous. Now, as Rayleigh has shown, the head normally 

 produces a sound-shadow for notes of these higher frequencies — no appreciable 

 sound-shadow is produced by the head for sounds of low pitch. The resulting 



