The relationship between speed of visual perception and flicker-induced harmonic cortical activity
department or school: Arts, Faculty of
department or school: Philosophy, Department of
data provider: DSpace
degree campus: UBCV
creator: Wright, Robert Leslie Douglas
issued: 2012-02-09T20:57:45Z
issued: 1956
related degree: Master of Arts - MA
degree grantor: University of British Columbia
description: The hypothesis was presented that speed of visual perception is related to degree of harmonic cortical response which can be elicited by intermittent photic stimulation, through some mechanism of CNS sensitivity to afferent stimulation. This hypothesis was based on Hebb's theory of the neuron assembly, and on Mundy-Castle's observations of the cortical effects of photic stimulation. Experimental examination of this hypothesis was made on a sample of fifty young adult volunteer subjects of both sexes. Recognition threshold was measured by tachistoscopic presentation of ten simple geometric patterns at exposures ranging upwards from ten milliseconds, until correct identifications of all patterns were made. The MRT score (recognition threshold) consisted of the average for the ten scores over an ascending and descending series. The EEG measurements were made in the conventional manner, and scored for variations in frequency pattern by measurement of electronic frequency analysis records. Photic stimulation at frequencies of 6 to 16 c/sec. was provided by an electronic stroboscope during the EEG recording. The results obtained from these procedures did not support the original hypothesis. The obtained correlation of 0.27 was not significant at the .05 level of confidence. An after-the-fact inspection of the data showed that the original hypothesis was applicable to roughly half of the subjects tested, and that these subjects could be selected by means of a third independent variable. The group showing this relationship was characterized by relatively high dominant EEG frequencies, and relatively loose organization of frequency pattern with little or no alpha activity In the normal or low frequency ranges. Due to limitations of method and sample size, this relationship could not be conclusively determined. While a generalization of universal validity was not established, one of restricted application was suggested. The possibility was discussed that speed of visual perce…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/40606
note: THE RELATIONSHIP BETWEEN SPEED OP VISUAL PERCEPTION AND FLICKER-INDUCED HARMONIC CORTICAL ACTIVITY by Robert L e s l i e Douglas Wright A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS i n the Department o f Ph i l o s o p h y and Psychology We accept t h i s t h e s i s as conforming t o the standard r e q u i r e d from c a n c i d a t e s f o r fefie degree o f MASTER OF ARTS. Members of the Department of P h i l o s o p h y and Psychology THE UNIVERSITY OF BRITISH COLUMBIA September. 1956 ABSTRACT The hypothesis was pres e n t e d t h a t speed of v i s u a l p e r c e p t i o n i s r e l a t e d t o degree of harmonic c o r t i c a l response which can be e l i c i t e d by i n t e r m i t t e n t p h o t i c s t i m u l a t i o n , through some mechanism o f CNS s e n s i t i v i t y t o a f f e r e n t s t i m u l a t i o n * T h i s h y p o t h e s i s was based on Hebb's t h e o r y of the neuron assemW.y, and on Mundy-Castle's o b s e r v a t i o n s o f the c o r t i c a l e f f e c t s o f p h o t i c s t i m u l a t i o n . Experimental examination o f t h i s h y p o t h e s i s was made on a sample of f i f t y young a d u l t v o l u n t e e r s u b j e c t s of both sexes. R e c o g n i t i o n t h r e s h o l d was measured by t a c h l s t o s c o p l c p r e s e n t a t i o n o f t e n simple geometric p a t t e r n s a t exposures ranging upwards from t e n m i l l i s e c o n d s , u n t i l c o r r e c t i d e n t i f i c a t i o n s o f a l l p a t t e r n s were made. The MRT score ( r e c o g n i t i o n t h r e s h o l d ) c o n s i s t e d o f the average f o r the t e n scores over an ascending and descending s e r i e s . The EEG measurements were made i n the c o n v e n t i o n a l manner, and scored f o r v a r i a t i o n s i n frequency p a t t e r n by measurement o f e l e c t r o n i c frequency a n a l y s i s r e c o r d s . P h o t i c s t i m u l a t i o n at f r e q u e n c i e s…
has type: Thesis/Dissertation
is shown at: 10.14288/1.0302608
language: eng
degree discipline: Philosophy
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/40606