**4. Description of the research**

#### **4.1. Aim**

Assessment of the condition of complex forms of non-verbal visual gnosis in children with typical development at pre-school age and differentiation of subgroups with different levels of functioning of perceptive processes.

#### **4.2. Method**

For the study of visual gnosis under difficult conditions, the neuropsychological probe "Recognition of incomplete images" was used. The sample is based on the holistic principle of sensory integration and is widely used [26, 41]. In a manner of implementation, it is close to the image recognition test with a decreasing degree of fragmentation [42, 37].

As mentioned above, task execution activates the occipito-temporal part of the right hemisphere (ventral visual system) and prefrontal cortex. The results of recognizing objects in conditions of shortness of signs provide information on the state and dynamics of the functioning of these regions. Neural processes responsible for mental "filling--in" the missing information in visual incentives, some authors [37] mean by the term "perception of closing". The phenomenon is a combination of areas known as the lateral-occipital complex (LOC) that is linked to a wide network of dorsal and frontal regions. Studies with functional magnetic resonance imaging (fMRI) confirm the leading role of the lateral-occipital complex in detecting hidden objects [43].

The sample we use contains 12 black and white incomplete images of objects (lamp, sword, spoon, anchor, pliers, kettle, teapot, needle, key, guitar, scissors and ring). Some of them are presented below (**Figures 1**–**4**).

**Figure 1.** Lamp.

The differences reflect the underdevelopment of the regulatory components of visual recognition in the pre-school period, shown by the large number of mistakes in children aged

Testing through event-related potentials for perceiving fragmented shapes in children aged 5–6 years separates two subgroups: A subgroup with a small number of errors and a B subgroup with a large number of errors [26]. In the second subgroup, a delayed development of two systems was recorded: the ventrolateral visual system and the dorsolateral prefrontal cortex responsible for regulatory functions and in particular for inhibitory control. Inhibitory control determines the successful recognition of the figures, whereas its absence explains the impulsive responses of children with low scores. The conclusion is that the morpho-functional maturity of the neuron systems processing sensory information and the state of regulatory functions determine children's individual abilities to visual recognition and their readiness for school education. The image identification in conditions of sign shortness assesses the functioning of the righthemisphere mechanisms and the implementation of a holistic perceptive strategy and is one of the most complex gnostic tasks. Difficulties in building hypotheses by children explain the cases of refusal to name individual figures and the presence of perseverations (use of a single

The analysis of the existing data sets the period of 4–6 years as sensitive for the development of brain mechanisms for perceptive processing and for the formation of complex forms of visual gnosis. The specifics in the functioning of the gnostic operations in children with typical development in pre-school age have an important diagnostic and prognostic significance since the evocation of normative data allows for the separation of subgroups with different levels of perceptual functions and the differentiation of children at risk of learning difficulties. This is in line with the thesis [40] that any neuropsychological study in childhood pursues two purposes: the diagnosis of the condition of the function and the formulation of the treatment methods and approaches.

Assessment of the condition of complex forms of non-verbal visual gnosis in children with typical development at pre-school age and differentiation of subgroups with different levels

For the study of visual gnosis under difficult conditions, the neuropsychological probe "Recognition of incomplete images" was used. The sample is based on the holistic principle of sensory integration and is widely used [26, 41]. In a manner of implementation, it is close to

As mentioned above, task execution activates the occipito-temporal part of the right hemisphere (ventral visual system) and prefrontal cortex. The results of recognizing objects in conditions of shortness of signs provide information on the state and dynamics of the functioning of these

the image recognition test with a decreasing degree of fragmentation [42, 37].

5–6 [34].

28 Prefrontal Cortex

word for different images).

**4. Description of the research**

of functioning of perceptive processes.

**4.1. Aim**

**4.2. Method**

**Figure 2.** Anchor.

**Figure 3.** Teapot.

**5. Results**

and Age\*Gender (F = 3.7; p < 0.026).

psychic development.

The values of the F-criteria and the confidence probability (P) indicate that the two independent factors, age (F = 15.75; p < 0.000) and the location (settlement), (F = 4.89; p < 0.008) have a statistically significant impact on the dependent variable for recognizing incomplete images. There is also a significant impact of the paired interaction, Age\*Settlement (F = 3.93; p < 0.003)

The Dynamic Maturation Process of the Brain Structures, Visual System and Their Connections…

http://dx.doi.org/10.5772/intechopen.79169

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The profile of the age factor shows a graduate growth in the score for the test, most prominent for the 5-year-olds. The biggest differences are the average scores for children aged 4 and 5 (**Figure 5**), which emphasize the importance of the fifth year for the dynamics of the neuro-

Duncan's test establishes statistically significant differences between any two means (**Table 1**). The influence and profile of the demographic factor on the development of the gnosis functions become obvious from the higher summarized score of the children from the big city (**Figure 6**). The average score of the children in the capital is lower, and the lowest is that of children from a small town. There is a statistical significant difference only between the average results of children from a large and a small town. The difference between the average points of children from a big city and capital is close to significance (p = 0.055), and among the children from a capital city and a small town the differences are not credible (**Table 2**).

Attention is paid to the interaction of age and gender factors. The data show identical average scores for girls and boys at 4 years of age, as well as similar ones for children at 5 years of age. Significant gender differences are only recorded in 6-year-olds. Duncan's test demonstrates the influence of both factors through specific differences between pairs of means (**Table 3**).

**Figure 5.** Effect of age factor on the results of recognizing incomplete images.

**Figure 4.** Scissors.

The investigation is individual and the answers are put in a separate protocol. Children look consistently at each of the stimuli and name it. All answers are noted regardless of their nature (correct or incorrect).

Assessment criteria:


The features of the functional system of visual perception are determined by indicators such as accuracy, completeness, volume and time for perception. In our case accuracy of perception is measured by using two parameters: number of correct answers and typology of the incorrect answers.

A total of 365 typically developing children without diagnosis of visual disorders took part in the research. All children attend state nursery schools and have Bulgarian as the mother tongue. They form three age groups: 4-year-olds (116 children); 5-year-olds (128 children); and 6-yearolds (121 children). Besides the age factor, the children were separated according to the size of settlement they live in (demographic criterion)—195 children from the capital, 90 living in a big city and 80—in a small town. The proportion according to gender is 173 males and 192 females.

The results are operated with a tri-factor dispersion analysis.
