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T Zabłocka

Publications and source records attributed to T Zabłocka.

10 recordsLinked to original sources
PubMed1996

Object discrimination learning and object-pattern discrimination transfer in visually deprived cats.

We used binocularly deprived cats (BD cats), control cats reared in the laboratory with open eyes (C cats) and normal wild cats (N cats). In stage 1, the cats were trained to discriminate a black ping-pong ball and a 3-dimensional cross of the same size and color for food reward. The BD cats learned slower than N cats. The difference between BD cats and C cats was statistically insignificant. A comparison of these data and previous data on discrimination of corresponding 2-dimensional black patterns (disk and cross) show that in discrimination learning the 3-dimensionality of stimuli is helpful for N cats, but not for BD cats. Thus, the objects and their patterns are for BD cats highly similar. In stage 2, the objects were replaced by corresponding 2-dimensional patterns (disk and cross). Pattern discrimination was learned slower by BD cats than by N cats. Thus, the objects and their patterns are for BD cats certainly not identical and BD cats are deficient in discrimination transfer of even highly similar pairs of visual stimuli.

Animals↗
PubMed1996

Discrimination learning of grating orientation in visually deprived cats and the role of the superior colliculi.

Four cats deprived binocularly of pattern vision (BD cats), 4 control cats reared also in the laboratory (C cats), and 4 normal wild cats (N cats) were trained to discriminate gratings of progressively smaller difference in orientation. Differences in learning were found only in fine orientation discriminations. The stage of 15 degrees orientation difference was learned by 4 N cats, 2 C cats, and 1 BD cat. After the discrimination training, the superior colliculi were ablated in 2 C cats and 2 BD cats. In contrast to C cats, the BD cats were very deficient and failed to relearn even a horizontal versus vertical orientation discrimination. Thus, an abnormal neural strategy used by BD cats diminished their deficit in grating discrimination learning.

Animals↗
PubMed1993

Discrimination learning of the vertical and horizontal light spot oscillations in normal and visually deprived cats.

Three groups of cats were used: cats deprived binocularly of patterned vision from birth (BD cats), control cats reared in the laboratory with opened eyes (C cats) and cats reared in a rural environment during the first months of life (N cats). The cats were trained to discriminate vertical vs. horizontal oscillations of a light spot for food reward. The task was difficult for all cats. The presumable reason was that the majority of neurones discriminates best between two opposite directions of movement and this mechanism was useless in the task. The learning was only slightly impaired in the BD group and only as compared with the N group. Our main conclusion is that a reduced number of directionally selective neurons in BD cats was still sufficient for movement discrimination learning.

Animals↗
PubMed1991

Brightness-discrimination learning in cats is influenced by early visual deprivation.

A two-choice apparatus for food reward was used. Normal and visually deprived cats were trained to discriminate white and black cards. After the animals had reached criterion, the contrast difference between the cards was diminished in steps. When the brightness ratio had been reduced to 1.8, discrimination was impaired in the deprived cats and not in the normally raised cats.

Animals↗
PubMed1990

Partition between stimuli slows down greatly discrimination learning in binocularly deprived cats.

Pattern discrimination learning was compared in cats reared in a normal environment during the first months of life (N cats), control cats reared in the laboratory with opened eyes (C cats), and cats deprived binocularly of patterned vision from birth (BD cats). A two-choice apparatus was used for training. In Expt. I the cats had been trained without a partition between stimuli and retrained with the partition. In Expt. II the partition was used from the beginning of training. The partition slowed down the learning in all groups. However, the BD cats were much more affected than N cats, and C cats seemed to be more affected than N cats and less than BD cats. In BD and C cats the number of errors of entering an incorrect alley without pushing the gate was increased. In contrast, when the partition was absent and discrimination very simple (stimulus vs no stimulus), the BD cats seemed to master the task even more quickly than N and C cats. The results suggest that the deficit produced by the partition consisted largely in a difficulty in rapid choosing a correct directional response at distance. In BD cats the mechanism of the deficit was complex.

Animals↗
PubMed1988

Binocularly deprived cats are normal in visual discrimination learning in a simple apparatus.

Pattern discrimination learning was compared in three groups of cats: reared in normal conditions, reared in the laboratory with opened eyes, and deprived of patterned vision from birth. A four-choice apparatus without partitions was used. The figure of a disc was reinforced with food, whereas a cross, triangle and square were not. All groups reached criterion after similar numbers of trials and errors, indicating that in binocularly deprived cats, simple perceptual and associative learning are not impaired.

Animals↗
PubMed1986

Permanent deficit of interocular transfer in binocularly deprived cats.

Fifteen laboratory born cats were used: seven binocularly deprived, four reared under condition of daily alternating monocular exposure and four controls. At the 7th month of age four of the binocularly deprived cats and all the remaining cats were trained monocularly in a two choice apparatus. In the first stage of training the cats learned a test with the right eye and were tested for transfer to the left eye. In the second stage, a new test was learned with the left eye, after which transfer to the right eye was tested. Control and with alternating monocular exposure cats had a normal interocular transfer whereas the binocularly deprived cats showed an impairment. After this training all binocularly deprived cats had the hoods taken off for 8 months and were then trained with new tasks. Their interocular transfer was still impaired. Thus, binocular pattern stimulation in the early period of life - simultaneous or alternate - is necessary for normal interocular transfer.

Animals↗
PubMed1983

Visual field measurements in binocularly deprived cats.

Visual fields were measured in 4 binocularly deprived cats and 2 controls. The animals were tested monocularly in the area between 60 degrees contralateral to the open eye and 105 degrees ipsilateral. No difference was found between visually deprived and control cats in response to stimuli presented in the binocular segment of the visual field from 30 degrees contra laterally to 30 degrees ipsilaterally. The stimuli placed on the 45 degrees line contralaterally elicited a lower response in binocularly deprived cats than in the controls. The results show that in binocularly deprived cats the visual field can be controlled by the retinal periphery up to 45 degrees.

Animals↗
PubMed1980

Loss of object discrimination after ablation of the superior colliculus-pretectum in binocularly deprived cats.

The effects of ablation of the superior colliculus-pretectum on a previously elaborated object discrimination task were compared in cats reared in normal conditions, in cats reared in the laboratory, and in cats deprived of patterned vision. The normally reared cats were least deficient postoperatively, whereas deprived cats were most deficient. Seven of 8 deprived cats failed to re-reach criterion. Previous results showed that after removal of the visual cortex deprived cats were less deficient than normally reared controls. It is concluded that in discrimination learning the function of the abnormal visual cortex of deprived cats is partially taken over by the superior colliculus-pretectum.

Animals↗