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Biomedical subjects

Z A Zorina

Publications and source records attributed to Z A Zorina.

At least 19 recordsLinked to original sources
PubMed2003

Prototype symbolization in hooded crows.

Studies were undertaken to determine whether four crows previously trained to an image-based abstract selection rule could establish a relationship between the number of elements in a group and initially indifferent symbols (arabic numerals) and operate with these symbols, i.e., studies addressed the ability of these birds to symbolize. Unlike other similar studies, there was no use of special development of associative connections between the symbols and the corresponding arrays of elements, but conditions were created in which birds could observe these relationships on the basis of comparison with previously obtained information. Demonstration series were performed for this purpose, in which correct solutions by the crow resulted in receipt of a number of larvae corresponding to the number of elements in the array pictured or numeral imaged on the stimulus selected by the crow. Images belonged to the same category as the corresponding stimulus for selection (the second stimulus was another category): if the image was an array, then the corresponding picture for selection also bore an array, and vice versa. Crows could solve the task successfully by using an image-based selection rule. In test series, the image and both selection stimuli were initially from different categories: if the image was a numeral, then both selection stimuli were arrays, and vice versa. All four crows successfully coped with this task. Despite the absence of any similarity between the image and "correct" stimulus, they selected the array corresponding to the numeral and vice versa. It is suggested that the birds could achieve this result by comparing the information obtained during the presentation series--about the number of reinforcement units corresponding to each stimulus. Similar experiments showed that crows could use numbers to perform operations analogous to arithmetic addition.

Animals↗
PubMed2000

Use of number by crows: investigation by matching and oddity learning.

Hooded crows were trained in two-alternative simultaneous matching and oddity tasks with stimulus sets of three different categories: color (black and white), shape (Arabic Numerals 1 and 2, which were used as visual shapes only), and number of elements (arrays of one and two items). These three sets were used for training successively and repeatedly; the stimulus set was changed to the next one after the criterion (80% correct or better over 30 consecutive trials) was reached with the previous one. Training was continued until the criterion could be reached within the first 30 to 50 trials for each of the three training sets. During partial transfer tests, familiar stimuli (numerals and arrays in the range from 1 to 2) were paired with novel ones (numerals and arrays in the range from 3 to 4). At the final stage of testing only novel stimuli were presented (numerals and arrays in the range from 5 to 8). Four of 6 birds were able to transfer in these tests, and their performance was significantly above chance. Moreover, performance of the birds on the array stimuli did not differ from their performance on the color or shape stimuli. They were capable of recognizing the number of elements in arrays and comparing the stimuli by this attribute. It was concluded that crows were able to apply the matching (or oddity) concept to stimuli of numerical category.

Animals↗
PubMed1993

A genetic, physiological, and biochemical investigation of audiogenic seizures in rats.

Two kinds of audiogenic seizures are characteristic of the KM rat strain, selected by Krushinsky and Molodkina in Moscow in the 1940s. This strain is now approximately 100% sound sensitive. Diallel crosses have demonstrated the polygenic nature of this behavior, with most alleles for seizures being recessive. Myoclonic seizures which develop after several sound exposures are a special form of kindling, involving the limbic system. Selection for low and high rates of myoclonic seizures was successful. Several unique, physiological features of the audiogenic seizures in this rat strain are described, as well as data on RNA and protein synthesis inhibition effects on seizure formation.

Acoustic Stimulation↗
PubMed1982

[New method of evaluation of reasoning ability in birds].

A study was made on 52 birds of five Corvidae species of the ability to solve an elementary logical problem proposed by L. V. Krushinsky and N. P. Popova for the assessment of non-verbal human thinking. In the problem the bait was placed in turn in each of twelve similar food cups located in one row and covered with lids. The first and second time the bird could detect the bait only by means of random search, while by the third presentation it obtained the information necessary and sufficient for errorless determination of the bait location. It was found that 25% of the studied birds coped with the problem, although some solutions were "incomplete" since along with errorless choices, the bird found the bait only after opening one or two empty cups, located near by. The data obtained attest that the Corvidae are capable of a determination of a discrete stimulus displacement schedule presented by the experimenter. This fact may be considered as one more evidence of a high level of the Corvidae reasoning ability, since the problem presents a greater degree of complexity as compared with the tests previously used.

Animals↗
PubMedDate not supplied

Quantitative evaluations in gray crows: generalization of the relative attribute "larger set".

Four gray crows were trained to choose the larger of two sets presented to them within the "1-12" range. The color, form, and size of the stimulus elements on cards, as well as the patterns of their disposition, were varied constantly during training, while at the same time prohibiting the use of extraneous features not relating to the number of elements. In order to exclude choice on the basis of the total area of the elements, series of presentations with variation of the ratio of the number of elements and their total area were carried out: in half of the presentations the larger set consisted of small elements, and the smaller set of large elements; in the second half, the reverse. In this range all of the birds demonstrated a high accuracy of evaluations (75.3 +/- 2.4%), including when there were minimal differences between the sets to be compared. Thus, in the "1-12" range, the crows were found to be capable of accurately comparing sets precisely on the basis of the number of elements in them. When a transition was made to a new "10-20" range, all of the crows demonstrated a successful transfer of the developed reaction (71.5 +/- 2.3%). However, when the ratio of the number of elements and their total area was varied, only two birds were able to cope with this task (71.9 +/- 3.6%). Overall, the results obtained indicate a capacity of crows for the formation of the concept "larger set," and are regarded as a manifestation of a high level of development of reflective activity.

Animals↗
PubMedDate not supplied

Capacity of birds for transitive inference: the solution of the Gillan test by corvids and pigeons.

A system of four to five differentiations forming a series, in which the magnitude of the reinforcement (R) of each succeeding color stimulus was greater than the preceding by one unit, was formed in pigeons (Columba livia L.) and crows (Corvus corone cornix L.). The number of units of the R that was associated with each of the stimuli increased successively from stimulus pair to stimulus pair from one up to four to five (1st series) and from five to ten (2nd series). After the development of the system of differentiations, the capacity of the birds to compare the magnitudes of R in given new combinations of stimuli and to choose the stimulus associated with the greater R (transitive inference) was tested. Given small Rs, the pigeons and crows solved the test equally successfully; in the case of large reinforcements, the pigeons began to make random choices, while in the crows the proportion of correct choices decreased. The proportion of appropriate solutions was greater when it was a greater absolute difference between the number of units of the R to be compared. The solution of the test employed by the birds is not proof of their capacity for transitive inference, since it can be explained by their capacity for unexpected comparison of the absolute values of the R associated with each of the stimuli.

Animals↗
PubMedDate not supplied

[Ability of birds of the Corvidae family to operate by the empirical dimensions of figures].

The reasoning ability was investigated in 29 Corvidae birds. The experimental task consisted in finding a hidden bait, the task being based on the fact that volumetric bait could be hidden in a volumetric geometrical figure only and not in a flat one. Thus it was possible to value the bird's ability to operate the empirical dimensions of objects. It was found that although the structure of bird brain is basically different from that of mammals, Corvidae surpass carnivorous mammals (dogs and cats) in solving this problem, their ability to operate the dimensions of objects being developped almost as well as that of monkeys.

Animals↗
PubMedDate not supplied

[Prototype symbolization in hooded crows].

The ability in prototype symbolization was studied in four crows trained in matching concept. The experimental approach was characterized by the absence of direct training providing an association between the pictured arrays and Arabic numerals. Experimental sessions were divided into demonstrative and test phases. In the demonstrative phases, the sample and the reinforced stimulus belonged to the same category: if the sample was a pictured array, the reinforced stimulus was also the pictured array, if the sample was a numeral, the reinforced stimulus was likewise a numeral. Matching-to-sample competence was sufficient to perform this task successfully. In case of a correct choice a crow received some mealworms, their number was equal to the number of items in the pictured array or the Arabic numeral. In the test phases, the sample and the comparison stimuli were of different categories. If the sample was a pictured array, the comparison stimuli were numerals; if the sample was a numeral, the comparisons were the pictured arrays. Such tests required the birds to choose a numeric symbol corresponding to the pictured array or to choose the array of pictured items numerically equal to the Arabic symbol. All four crows performed this task successfully. Birds were able to set up a correspondence between the Arabic numeral from 1 to 4 and the number of elements in pictured arrays by way of mental juxtaposition of the earlier received information. Similar experiments showed that crows are likely to be able to perform mental operations with numerals analogous to simple arithmetic addition.

Animal Communication↗
PubMedDate not supplied

[Behavioral impairments in Morris water maze in rats selectively bred for audiogenic seizure susceptibility (Krushinsky-Molodkina strain)].

Krushinsky-Molodkina rats (KM strain) with genetically determined seizure susceptibility (clonic and tonic seizures in response to the sound of an electric bell, Krushinsky, 1960) were tested in two versions of Morris water maze and compared with normal albino rats (Sprague-Dawley and Wistar). The tests revealed a learning deficit in KM rats. They showed slow acquisition in both the spatial version of the test and the version with the platform, less efficient strategy of searching for target platform, and high scores of floating and thigmotaxis. However, males of KM rats (not females) did not differ significantly from Wistar strain in the probe trial in the spatial variant of the Morris test. No preference for searching for the platform at the place of its previous localization was observed in KM females. Together with our previous findings of the low scores in Revecz-Krushinsky test and data of other authors (Batuev et al., 1983) concerning a working memory deficit in the radial maze, the results suggest the of complex cognitive deficit combined with possible increased stress reactivity in KM rats.

Animals↗
PubMedDate not supplied

[A comparison of problem solving by extrapolation before and after removal of the archicortex and Wulst in cows].

The change in the capacity for extrapolation was studied in crows after ablation of Wulst and the archicortex. After the ablation of the archicortex, the solution of the extrapolation problem does not change. After the ablation of Wulst, the number of "refusals" to solve increases, the number of correct responses diminishes, although it remains significantly higher than the number of errors. It is assumed that the archicortex and Wulst play no decisive part in the process of solving problems involving extrapolation; yet Wulst apparently controls the achievement of the final reaction, by-passing the screen.

Animals↗
PubMedDate not supplied

[Analysis of the effect of a training regime for the correct choice of matched learning in gray crows].

It was shown that a large set of training stimuli promotes abstract concept learning. These experiments were designed to assess whether an application of a large set of training stimuli would facilitate matching learning in crows. Four hooded crows were trained with a set of 72 unique combinations of stimuli in two-alternative simultaneous matching tasks with stimuli of three different categories: achromatic color (white, light-grey, dark-grey, and black), shape (Arabic numerals from 1 to 4 used as visual shapes only), and number of elements (heterogeneous graphic arrays from 1 to 4 items). Although the performance of all crows was significantly above chance (p < 0.01) in some 72-trial blocks, birds were unable to establish matching and to reach the criterion of learning 80% correct or better over 72 consecutive trials) in 5184 trials. Thus, the modified training procedure was less efficient than the training technique previously used (successive cyclic repetition of three small sets of training stimuli), which allowed four of six crows to acquire the matching rule after 1780, 2360, 3830, and 5260 trials [4,9].

Animals↗
PubMedDate not supplied

[Evaluation of the ability to solve the Revecz-Krushinskiĭ test in corvine birds].

Reasoning ability in crows was investigated by means of the Revecz-Krushinskiĭ test, in which the bird has to apprehend the rule of stimulus (food bait) displacement: "In each next trial the food bait is hidden in a new place--one step further along the row". By means of computer modelling the criteria of statistical evaluation of this problem solving were established. The test was considered solved when the number of trials which preceded the detection of food was less than those which were calculated for chance performance. High level of reasoning ability in crows is discussed.

Animals↗