Spatial perception in colliculectomized and normal golden hamsters (Mesocricetus auratus)

Abstract

Held and Schneider and others have postulated two, functionally separate, modes of vision-one concerned with localization, the second with identification-and have suggested that the superior colliculus is crucial for the perception of location. Colliculectomized hamsters were tested on two localization tasks. No deficit in depth perception was observed. Perceptual-motor integration necessary to perform a search task was severely disrupted, however. These results suggest that the superior colliculus functions in the control of fine visual-motor coordination.Research by Schneider (1969) has specified anatomical loci for two functional mechanisms of vision in golden hamsters. Colliculectomized subjects in a discrimination task could discriminate simple patterns, but could not orient or locomote directly to the correct pattern. Conversely, animals with ablations of the visual cortex displayed an impaired ability to discriminate patterns, but no loss of ability to orient and localize.These results, in addition to those of Held (1968), Ingle (1967), and Trevarthen (1968, have led these authors to postulate two different modes of visionthe first concerned with "location" and the second with "identification." The term "location," however, refers to a wide range of behaviors which require the pickup of different types of stimulus information, and which demand varying degrees of visuomotor integrative ability in order to be performed. The question arises that perhaps a lesion in a specific area of the brain could interfere with an animal's performance on one task involving "location" while another behavior that can be categorized under the same heading remains intact. That this may be the case is suggested by previous studies involving ablations of the superior colliculus. For example, Lashley (1937) demonstrated that rats with lesions in the superior colliculus could negotiate jumps of between 20 and 40 cm to a platform without any difficulty, and found that the The authors wish to thank Gerald Schneider for his advice on the surgical procedures used in these experiments, P. A. Cabe for his suggestions concerning the open-field test, and E. J. Gibson for her advice and encouragement. Requests for reprints should be sent to Richard R. Rosinski,

Acquisition of visuomotor behavior after neonatal tectal lesions in the hamster: The role of visual experience.

“…Some evidence of a similar slight retardation may be seen in the appearance of a preference for the shallow edge by the colliculus-ablated animals on Days 23 and 27 ( Figure 6). We confirm the observation of Keselica and Rosinski (1976) that collicular lesions do not impair depth judgments in mature hamsters, but we do show evidence of a developmental lag in this capacity consequent to colliculus lesions. Visual approach and orienting.…”

The role of the superior colliculus in visually guided locomotion and visual orienting in the hamster

“…Like several other investigators (Dyer et aI., 1976;Goodale & Murison, 1975;Keselica & Rosinski, 1976), we have failed to find evidence of a deficit in visually guided locomotion in rodents after collicular lesions, in contrast to the findings reported by Schneider (1969). Schneider's formulation is so compelling, however, that it is necessary to account for the discrepancy between laboratories in some detail.…”

“…This response mode allows the hamster to acquire food and investigate novel objects, as has been described for anurans (Ewert, 1970;Ingle, 1973). Keselica and Rosinski (1976) have shown that hamsters with collicular undercuts fail to use appropriate search and gathering strategies when presented with an array of sunflower seeds. A second use for this response mode might also be possible: animals with retinal specializations successively orient their eyes so that the area of interest falls on the area of greatest receptor density, improving discrimination.…”

“…By contrast, hamsters with collicular undercuts or neonatal lesions showed no evidence of a deficit in visual guidance to goals marked by brightness or pattern cues. There is other evidence of visually guided locomotion in hamsters with collicular damage: hamsters with collicular undercuts can note the edge of a visual cliff and choose the shallow side with normal accuracy (Finlay et aI., 1980;Keselica & Rosinski, 1976), and they can locomote around stationary barriers with a speed and accuracy that is comparable to that of normal hamsters (Finlay et aI., 1979). This deficit may be described as the loss of a response mode, the ability to make head and eye movements to visual stimuli, which has implications for various types of orienting behavior.…”

Rodentia Sensory Systems

“…In the laboratory, several aspects of vision have been studied in rodent models. For example, depth perception has been evaluated in golden hamsters using visual cliff paradigm, similar to what is used in human infants, where subjects are faced with what appears to be the edge of a cliff with a patterned floor and if they can perceive depth differences, they will not go past the edge (Keselica and Rosinski 1976). Object identification can be tested in a visual open field test where food items are scattered around a grid and subjects are tasked with locating the food objects.…”