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R C Tees

Publications and source records attributed to R C Tees.

At least 37 records · Page 2Linked to original sources
PubMed1983

Effect of visual experience on the habituation of orienting behavior.

Orienting behavior elicited by novel visual and auditory stimuli was examined in light-reared (LR) and dark-reared (DR) rats at 30, 60, 90, or 120 days of age. Orienting behavior was assessed by examining the rat's ability to interrupt ongoing licking and perform appropriate head and postural adjustments when apparently moving or stationary light displays or tones were presented. When the lights were first presented to the LR and DR rats, their orienting behavior did not differ at any of the ages examined. However, age and visual experience did influence habituation and recovery of orienting with changes in the light display. The older DR rats habituated with fewer repeated presentations of the light displays than their LR counterparts and did not recover orienting as effectively to all the subsequent changes of the light displays. The younger LR and DR rats did not differ reliably. These results are discussed with regard to the nature of the habituation process for rodents and the relation between visual experience and habituation of attentional responses.

Animals↗
PubMed1982

Generalization after form discrimination in light-reared and dark-reared rats.

In 2 experiments the performance of 90- and 150-day-old light-reared and dark-reared rats was compared under appetitive reinforcement conditions on rigorous tests of form discriminative abilities. Although early stimulatory history had little impact on either the ability to discriminate shapes on the basis of contour orientation or to generalize from that initial experience to lines in other orientations lack of visual experience did have significant consequences with respect to a comparable task in which the relationship between lines was the significant feature. Little change in the initial deficits was observed with exposure to a normal light environment for 60 days following the period of early visual deprivation in the case of this 2nd complex pattern discrimination task.

Animals↗
PubMed1981

The effect of early visual experience on spatial maze learning in rats.

In the 1st of 2 experiments on spatial ability, groups of sighted and blind, light-reared (LR) and dark-reared (DR) rats were tested on a series of (Hebb-Williams) maze problems and their reversals under appetitive and aversive reinforcement conditions. Significant effects due to early rearing conditions, vision at time of testing, and problem were found. Dark-reared rats learned the problems whose solution depended on nonvisual cues more slowly than LR animals. Blindness at time of testing had a significantly adverse effect on the performance of LR and DR rats on all problems, but a significantly greater effect in the DR animals. In a 2nd experiment DR rats were also found to perform less effectively than LR rats on a 17-arm radial maze throughout a 36-day period during which variations in the task were introduced. The results reveal the impact of early visual experience on the development of the ability to acquire spatial concepts.

Animals↗
PubMed1981

Orienting behavior by rats with visual cortical and subcortical lesions.

The effect of visual cortical and subcortical lesions on orienting behavior was assessed bu examining the rats' ability to interrupt an ongoing response and perform appropriate head and postural adjustments to repeatedly presented auditory or apparently moving visual stimuli. Large lesions of the entire superior colliculus (SC) or the deep layers of the SC did not result in visual agnosia or the inability to perform the motor responses involved in orienting. Rather, the orienting response simply ws not emitted to visual stimuli that the intact rat treated as less salient, but was to those it treated as more salient. Lesions of either the superficial layers of the SC or visual cortex also did not completely prevent orienting to very salient, apparently moving visual stimuli, but did produce changes in the number of responses made to such stimuli and in the occurrence of other components of orienting behavior. It was suggested that the SC and visual cortex play a modulatory role in orienting behavior and that stimulus characteristics must be considered in the development of neuronal models of orienting behavior.

Animals↗
PubMed1981

Developmental aspects of cross-language speech perception.

Previous research has suggested that infants discriminate many speech sounds according to phonemic category regardless of language exposure, while adults of one language group may have difficulty discriminating nonnative linguistic contrasts. Our study attempted to address directly questions about infant perceptual ability and the possibility of its decline as a function of development in the absence of specific experience by comparing English-speaking adults, Hindi-speaking adults, and 7-month-old infants on their ability to discriminate 2 pairs of natural Hindi (non-English) speech contrasts. To do this, infants were tested in a "visually reinforced infant speech discrimination" paradigm, while a variant of this paradigm was used to test adults. Support was obtained for the above hypotheses. Infants were shown to be able to discriminate both Hindi sound pairs, and support for the idea of a decrease in speech perceptual abilities wih age and experience was clearly evident with the rarer of the 2 non-English contrasts. The results were then discussed with respect to the possible nature and purpose of these abilities.

Child Development↗
PubMed1980

Effect of controlled rearing on the development of stimulus-seeking behavior in rats.

In three experiments, the performance of differentially reared rats was compared at 15 through 90 days of age in an experimental situation in which the amount of self-exposure to various lighted displays was being measured. The kind of visual array preferred by these animals was significantly influenced by both their ages and visual stimulation histories. Preference for light arrays involving features significantly increased in the case of light-reared and bias-reared rats beginning at 60 days of age. At the same time, a preference for diffuse light stimulation emerged in the case of their dark-reared (DR) controls. Although the significant increase in light-seeking exhibited by all groups of animals at 60 days of age was found to be unrelated to previous testing in the situation, the visual experience associated with repeated tests did "protect" DR rats from the decline in light-seeking observed after prolonged visual deprivation. Potential species differences and the nature and specificity of these changes in visual behavior are further discussed with respect to the role of early experience in visual development.

Aging↗
PubMed1979

The effect of visual deprivation on pattern recognition in the rat.

In 2 experiments the performances of light-reared (LR) and dark-reared (DR) 90-day-old rats were compared on a variety of transfer tests following acquisition of 3 pattern discriminations. Significant differences due to rearing condition were found in performance on a discrimination involving horizontal separations between pairs of vertical contours. No such differences due to rearing were observed during either acquisition or transfer testing of a discrimination involving pairs of mirror image oblique contours. Significant differences due to rearing were observed in acquisition of a discrimination between a checkerboard pattern and a similar pattern containing an irregularity and in performance on a subsequent series of transfer tests. The results suggest that the spatial integration necessary to discriminate basic as well as complex relational properties between linear elements involves mechanisms which require experience for their development and maintenance.

Animals↗
PubMed1978

The effect of visual deprivation in the rat on transfer effects after form discrimination training.

In 3 experiments the performances of light-reared (LR) and dark-reared (DR) 90-day-old rats were compared on a variety of transfer tests following acquisition of 3 discriminations involving patterns of small squares (dots). Though no significant difference due to rearing condition was found in acquisition of those discriminations consisting of single lines of dots in various orientations, transfer tests did reveal subtle differences in the way LR and DR rats analyze contour information. Significant differences due to rearing were also observed on the acquisition of a complex dot pattern (gradient vs X) and, in spite of overtraining, on subsequent stimulus equivalence tests. Anomalous transfer effects were not observed in any of these test situations.

Animals↗
PubMed1978

Extent of recovery of function after early sensory deprivation in the rat.

In two experiments the performances of 90- and 150-day-old light-reared and dark-reared rats were compared on rigorous tests of depth and form discriminative abilities. Significant differences due to rearing and age were found. Exposure to a normal light environment for 60 days was found to partially alter the effects of an early 90-day period of visual deprivation in the case of depth discrimination but to have little impact in the case of form discrimination. The implications of the results are discussed with regard to the proposition that the initial deficits in the performance of the dark-reared rats and the extent of recovery of function after exposure to a normal environment are related to the kind of perceptual ability being measured and to the sensitivity of the test.

Age Factors↗
PubMed1976

Depth perception after infant and adult visual neocortical lesions in light- and dark-reared rats.

In 2 experiments the behavior of light- and dark-reared infant- and adult-operated striate rats were compared at 20-160 days of age on a visual cliff apparatus in which the depth of the deep side could be varied. Differential depth thresholds revealed that depth discriminative ability did not develop normally following removal of the striate cortex in infancy. Further, infant-operates who were reared in darkness following their operations performed less well than their light-reared, infant-operated counterparts. The infant-operated animals, regardless of their postoperative rearing condition, performed significantly better than did adult-operated animals after comparable post-operative recovery periods and testing. The results are discussed in terms of further specification of the role played by age of operation and by the interaction between visual experience and age of operation.

Age Factors↗