The nature of adaptation in distance perception based on oculomotor cues

In previous work by the senior authors, brief adaptation to glasses that changed the accommodation and convergence with which objects were seen resulted in large alterations in size perception. Here, two further effects of such adaptation are reported: alterations in stereoscopic depth perception and a change when distance is represented by a response of S’s arm. We believe that the three effects are manifestations of one primary effect, an alteration of the relation between accommodation and convergence on the one hand and the distance they represent in the nervous system (registered distance) on the other. This view was supported by the results of two experiments, each of which demonstrated that the alterations in stereoscopic depth perception could be obtained after adaptation periods which had provided no opportunity to use stereoscopic vision, and that the adaptation effect was larger for depth perception than for size perception when it was obtained under the same conditions; the latter finding was expected if both effects resulted from the same change in registered distance. In three of the five experiments here reported, the variety of cues that could represent veridical distance during the adaptation period was limited. In one condition of adaptation, only the pattern of growth of the retinal images of objects that S approached and the kinesthetic cues for S’s locomotion served as cues to veridical distance. In two other conditions S remained immobile. In one of these, only the perspective distortion in the projection of the scene that S viewed mediated veridical distance, and in the other one familiar objects of normal size were successively illuminated in an otherwise totally dark field, conditions from which opportunities to use stereoscopic vision were again absent. After exposure to each of these adaptation conditions, adaptive changes in perceived size and larger ones in perceived stereoscopic depth were obtained. Because we found that familiar size may serve as the sole indicator of veridical distance in an adaptation process, we concluded that it can function as a perceptual as distinguished from an inferential cue to distance.     

Adaptation in distance perception based on oculomotor cues

Accommodation and convergence primarily serve to adjust the eyes to the distance of the object viewed, but, once made, these oculomotor adjustments serve as cues for the object’s distance. Experiments are reported that show that the relation between oculomotor adjustments and the distances they signify can be changed by adaptation to glasses that cause alteration in the oculomotor adjustments with which objects are viewed. This changed relation manifested itself in marked alterations of size perception. Wearing, for 30 min, glasses that caused a change in accommodation and convergence corresponding to a smaller object distance and equivalent to 1.5 lens diopters caused subsequent mean size increases that ranged from 50% to 65%. Adaptation to glasses that changed oculomotor adjustments in the same amount but in the opposite direction resulted in decreases in perceived sizes that varied from 18% to 40%, dependent on the distance of the test object. These were the results of size estimates obtained before and after the adaptation period under conditions where only accommodation and convergence served as cues for distance. A newly developed test of size perception was also used, in which S adjusted the size of the projected image of an array of familiar objects on a screen until the size of the objects appeared normal. Again, such adjustments were made before and after the adaptation period, and size differences were obtained that were in the direction to be expected of adaptation and varied in amount between 12% and 33%, dependent on the distance of the screen. The reason for the different amounts of size change measured by the two kinds of tests was investigated.     

Successive luminance difference thresholds and brightness as a function of the interstimulus interval and durations of successive flashes

Monocular,successive luminance difference thresholds (ΔI) and brightness matches (PSE) were obtained by the method of constant stimuli for two flashes successively presented to the same retinal area. Variations in interstimulus interval first-flash duration,and second-flash duration were the independent variables investigated. ΔI decreased as a function of ISI,while PSE remained relatively uninfluenced. An intensity-duration reciprocity was observed with increases in either first- or second-flash duration. Equal increases in duration of both flashes led to a constant value of ΔI. A Broca-Sulzer effect was also noted. In another study, a 10-msec, variable-luminance Standard was followed after 500 msec by either a 10-msec or a 320-msec test flash that was compared to the Standard. The results indicated that the rate of change of brightness with changes in luminance of the Standard was faster for the 10-msec flash than for the 320-msec flash. The rate-of-change hypothesis would predict that the 10-msec flash should have the smaller ΔI. The results for two Ss indicated the opposite: AI was smaller for 320-msec than for 10-msec flashes. A modification of the hypothesis was suggested such that it may be the energy increment (Δlt) required for detection that is related to the rate at which brightness changes with energy.     

Adaptation in the constancy of visual direction measured by a one-trial method

Adaptation to field displacement during head movements in the direction with the head rotation and in the direction against it was produced under otherwise identical conditions and compared; the field displacement rate was also varied. A rapid training procedure was used, and a novel one-trial test was employed that could measure the adaptation well enough to compare the effects of various training conditions. The one-trial test measured the magnitude of one of the manifestations of adaptation, the apparent displacement of a stationary target during head movements. This apparent horizontal target displacement was transformed into an oblique one by having the head movements that brought forth the apparent target displacement simultaneously cause an objective vertical target displacement. The slant of the resultant apparent motion path varied with the magnitude of the apparent horizontal target displacement. It was measured by having S reproduce its slant angle. It was found that adaptation to field displacement in the direction with the head rotation was consistently greater than adaptation to the opposite displacement conditions. An explanation for this result is offered.     

Cognitive behavior modification: ‘Motivated learning’ reading treatment with subprofessional therapy-technicians

A method of treating reading deficits based upon an extrinsic motivational system previously employed successfully with a single subject was extended to eighteen additional subjects. The junior-high age subjects included retarded children in special classes, several emotionally disturbed children, and culturally deprived children. The method of training used in the original study was designed to be simple to administer and simple to record the performance of the child. Thus, it was hypothesized that subprofessional personnel could be employed to administer the treatment. Adult volunteers and high school seniors were used as the therapy-technicians.

The eighteen Ss were given 38.2 hr of training in daily half-hour sessions, during which period the average reinforcement earned was $22.29. The mean number of single word reading responses was 94,425. The rate of reading accelerated over the period of training even though the reading material became more difficult. This occurred during a period when progressively less (about one-fourth as much) reinforcement was given per reading response. A mean of 593.5 new words were learned and 70.9 per cent of these were retained in a long-term test. The attention, attendance, cooperation, and diligent work behavior of the various children were maintained in good strength throughout the duration of the study. The results suggest that research be conducted to develop methods for treatment of behavioral deficits that can be widely applied by subprofessional therapy-technicians supervised by clinical psychologists.     

Internal and External Ethnic Identity and Their Correlates: A Study of Chinese American Immigrants

The measurement of internal ethnic identity and external ethnic identity showed that Chinese American immigrants could be differentiated into different identity groups. Additionally, internal ethnic identity significantly predicted salience of ethnicity and loss of face. Income, ethnicity salience, external ethnic identity, and loss of face were significant predictors of acculturative stress.     

THE CREDIBLE SHRINKING ROOM:

Abstract— Becoming a proficient symbol user is a universal developmental last in the first years of life, but delecting and mentally representing symbolic relations can be quite challenging for young children To test the extent to which symbolic reasoning per se is problematic, we compared the performance of 2-year-olds in symbolic and nonsymbolic versions of a search task. The children had to use their knowledge of the location of a toy hidden in a room to draw an inference about where to find a miniature toy in a scale model of the room (and vice versa) Children in the nonsymbolic condition believed a shrinking machine had caused the room to become the model They were much more successful than children in the symbolic condition, for whom the model served as a symbol of the room The symbol understanding and use.     

Gender-related assessment of childhood play

Parent-report based scales for the assessment of sex-dimorphic behavior are an important tool in research on psychosexual differentiation and its disorders. This paper presents the factor analysis and corresponding scale development for the slightly expanded Child Game Participation Questionnaire (Bates & Bentler, 1973), based on the parents of a demographically diverse school sample of 355 girls and 333 boys aged 6 to 10 years. Evidence supporting each of three theoretical positions in gender assessment — unidimensional bipolar, two-dimensional unipolar, and multidimensional — was provided. Effect sizes were unusually large for gender, but small for age, socioeconomic level, and race/ethnicity.This research was supported in part by a NICHD postdoctoral fellowship (NRSA HD06726; sponsor: Dr. Meyer-Bahlburg) awarded to Dr. Sandberg, by grants to Dr. Ehrhardt and Dr. Meyer-Bahlburg from the Spencer Foundation, the William T. Grant Foundation, the Ford Foundation, and NIMH (center grant 2-P50-MH43520, Anke A. Ehrhardt, Ph.D., Principal Investigator), and by the NIMH Clinical Research Center grant MH-30906.We thank the children and parents who participated in the study. Dr. Jacob Cohen consulted on statistical matters. Ms. Patricia Connolly provided word processing services. A portion of this work was presented as a poster at the XIth Biennial Meeting of the International Society for the Study of Behavioral Development, Minneapolis, Minnesota, July 3–7, 1991 (Abstracts, p. 285).