48 research outputs found
Spectral sensitivity of macaque monkeys measured with ERG flicker photometry
No full textThe following is a correction for the article “Spectral
sensitivity of macaque monkeys measured with ERG flicker
photometry,” by Gerald H. Jacobs and Jess F. Deegan
II, that appeared in Visual Neuroscience, 1997,
14, 921–928. As a result of a transcription error
the spectral sensitivity values included in Table 1 were
incorrect.</jats:p
Gay and Straight Men: Differences in Proximal Memory Recall
No full textBiological, genetic, and cognitive differences exist between sexes, with analogous differences found for biological components between heterosexual and homosexual men. Therefore, similar cognitive differences should exist between heterosexual and homosexual men. One possibility, in spatial memory, was examined through a spatial / proximal memory recall test. After exposure to stimuli in either an incidental or directed condition, participants were asked to identify stimuli and locations when presented with pictures of stimuli and distracters. Correctly recalled items for both conditions were examined using an ANCOVA, with location as a covariant. An interaction was found for sexual orientation by condition, F (1,32) = 4.40, p = .041 , with homosexual men correctly recalling more items than heterosexual men in the incidental condition. These findings support the existence of a specific cognitive group difference between homosexual men and heterosexual men
Light Therapy Effects on Depression in Nursing Home Residents
No full textAccepted as the standard mode of therapy in the treatment of depression, antidepressants have a proven efficacy in the general population; however, as a result of altered physiological states, the efficacy of drug therapy in the treatment of depression among older adults remains tenuous at best. In seeking out a nonpharmacological intervention, this study measured the effects of phototherapy (light therapy) on older adults residing in a nursing home. Employing a double-blind, repeated measures design, light therapy, when compared to the no-treatment and low light levels, was found to (a) significantly decrease depression scores and (b) increase life satisfaction scores. Implications of these findings are discussed
The Role of Hormones in the Sexual Differentiation of Cognitive Processes
No full textA critical literature review is presented examining the relationship between hormone exposure and sex differences in cognitive processes. In addition to comparative research on the etiology of sex differences in behavior, findings regarding two cognitive abilities, verbal fluency and spatial ability, is summarized for four groups that experience differential hormone exposure (Turner's Syndrome females, homosexual males, Congenital Adrenal Hyperplasia females, and XYY Syndrome males). Findings regarding the cognitive patterns of modal females and males across the life span, cross-cultural comparisons, and research addressing convergence of cognitive sex differences follow. Conclusions and suggested areas for futher research are presented
Illusory Contour Perception Processing at Primary Visual Cortex: Transient and Steady-State VEPs
No full textIn studying consciousness, scientists have developed methods to test how visual information is "knit" together to form a unified perception of the physical world. Studying the phenomenon of illusory contours, contours perceived in spite of the lack of physical contours, is one method of studying visual awareness. In the present study, transient and steady-state VEPs, elicited in response to a Kanizsa square, real square, and control stimulus, were recorded from Oz and O2 in humans to see if these recording sites demonstrated that early processing areas are involved in the formation of illusory contour perception. Predictions were that N2 amplitude and latencies, recorded from the visual cortex in the transient tests, would be greater. In the steady-state tests, second harmonics would be significantly different to illusory contours as compared to controls. With the intermodulation (IM) modes, the IM components would be apparent in the illusory contours and not in the controls. The results were that N2 amplitudes, as predicted, were significantly greater for illusory contours as compared to controls. Although no latency differences were found between the N2 waveform between illusory and controls, other significant latency differences were identified. IM differences were not found between the illusory and control; however, other results were found supporting element binding as in contour formation
Cone pigment variations in four genera of new world monkeys
No full textAbstractPrevious research revealed significant individual variations in opsin genes and cone photopigments in several species of platyrrhine (New World) monkeys and showed that these in turn can yield significant variations in color vision. To extend the understanding of the nature of color vision in New World monkeys, electroretinogram flicker photometry was used to obtain spectral sensitivity measurements from representatives of four platyrrhine genera (Cebus, Leontopithecus, Saguinus, Pithecia). Animals from each genus were found to be polymorphic for middle to long-wavelength (M/L) sensitive cones. The presence of a short-wavelength sensitive photopigment was established as well so these animals conform to the earlier pattern in predicting that all male monkeys are dichromats while, depending on their opsin gene array, individual females can be either dichromatic or trichromatic. Across subjects a total of five different M/L cone pigments were inferred with a subset of three of these present in each species
