Perception Apparatus Research Articles

Effect of Age and Brain Damage on Depth Perception

There is evidence suggesting that the relationship between age and perceptual abilities is a complex function. Piaget and Lambercier (1956) have found that the abiliry to judge distances appears to be best in children from 7 to 8 years of age, decreasing from 10 to 12, and then increasing from 12 to 14 at which point it reaches the adult level. Wallace ( 1756) has shown that these abilities tend to decrease in older persons. A question arises however, as to whether the ability to judge depth is related entirely to the developmental changes in the central nervous system or whether it is also affected by traumatic brain damage. This study is a preliminary attempt to test the effect of brain damage, as well as age on depth perception. METHOD Sabjects.-Three groups of 10 males each were used. They were young normal, aged normal, and aged brain-damaged. The young normal group consisted of patients at the Biloxi Division of the VA Hospital, Biloxi, Mississippi. They ranged in age from 23 to 38 yr., with a mean of 32.5. The two aged groups consisted of members of the Domiciliary of the VA Center. The normal group ranged in age from 60 to 67 yr., with a mean of 64.0. These Ss showed no abnormal deterioration for their age as indicated by the tests mentioned below. The brain-damaged group ranged in age from 61 to 70 yr., with a mean of 65.2. The diagnosis of brain damage was made on the basis of five measures: clinical records, neuropsychiauic examination, the Graham-Kendall Mernoryfor-Designs Test (1946), the Spiral Aftereffect Test (Price & Deabler, 1955), and the Digits Backwards subtest of the WAIS (1955). All Ss took each test. Appara~zls.-The depth perception apparatus consisted of two vertical bars suspended down and into an oblong, wooden box 8 in. X 8 in. X 15 in. One bar, the standard, was stationary, and the other, the variable, could be moved back and forth along the length of the box by pulling on a string. At the front of the box, 8 in. from the standard, was an aperture 5 in. wide and 2% in. high. Seven inches behind the standard was a piece of ground glass, illuminated from behind by a 25-w incandescent bulb, and comprising the entire rear of the box. 'This paper was read at the Southeastern Psychological Association Meeting St. Augustine, Florida, in April, 1959.

Eyedness as Affecting Results Obtained with the Howard and Dolman Depth Perception Apparatus

(1949). Eyedness as Affecting Results Obtained with the Howard and Dolman Depth Perception Apparatus. The Journal of Psychology: Vol. 27, No. 2, pp. 479-482.

THE NEXT STEP IN AUDITORY RESEARCH

In preparing a discussion of the challenging theme of this symposium, we were guided by an old Greek dictum: "The rudiments must be strongest." In the realm of auditory research a multitude of complicated acoustic phenomena is being studied and analyzed for which adequate knowledge of the fundamental principles is not yet available. Therefore, in naming a most desirable "next step in auditory research," a better understanding of the cochlea and its mechanical functioning is chosen without much hesitation. This paper attempts to describe experimental possibilities for the study of the function of the cochlea. It is evident that the first stages in the process of hearing are physical, the transmission of acoustic energy from the external medium to the nerve endings in the cochlea. It is common to identify the anatomic term "middle ear" with the functional meaning "sound conduction apparatus." Similarly "inner ear" and "sound perception apparatus" are

CHICAGO LARYNGOLOGICAL AND OTOLOGICAL SOCIETY: Regular Meeting, Oct. 5, 1931

THE MECHANICS OF AUDITION. DR. A. G. POHLMAN. Audition is dependent on the conduction of vibrations that lie within the audible range to the end-organ, and on the transformation of the stimuli at the end-organ into action currents which are translated by the brain into terms of the sources. It is well known that the development of the vertebrate ear seemingly violates the physical requirements essential to an organ of great sensitivity, because the perceptive apparatus is an immersion end-organ, and because air sounds are almost completely reflected back in their conduction to water. The development of an immersion end-organ, however, fulfils the physiologic requirement of placing the perceptive apparatus under conditions of acoustic insulation, which permits great sensitivity in response. The acoustic insulation is overcome through the development of a middle ear that acts as a transformer to match the differences in resistance in the two mediums. The evidence