National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Hippocampal coding of positions of visual objects and prediction of their future interactions
Dvořáková, Tereza ; Levčík, David (advisor) ; Nekovářová, Tereza (referee)
The hippocampus is a crucial brain structure involved in spatial navigation. It contains populations of spatially sensitive cells as the place cells, head-direction cells, grid cells, border cells, or object-vector cells. These neurons together create a cognitive map of the environment that serves for navigation in space. The role of hippocampal cells in the encoding of positions of other objects has also been suggested. Other studies found so-called time cells in the hippocampus that are active during specific delays in a behavioral task and associated them with place cells. While there are recent studies researching the encoding of accessible objects' positions, the encoding of objects in the inaccessible space has lacked research. The neural representation of dynamic situations (that constitute the majority of real-world encounters) has also been only scarcely researched. We designed a behavioral task to study the learning of static and dynamic spatial visual scenes presented in the inaccessible space and combined it with single-unit electrophysiological recording from the CA1 area of the hippocampus of freely moving rats. Our results show that rats can discriminate both static and dynamic inaccessible spatial stimuli, and that they prefer dynamic over static stimuli. They can also generalize...
EEG correlates of egocentric and allocentric distance estimates in virtual environment in humans
Kalinová, Jana ; Vlček, Kamil (advisor) ; Telenský, Petr (referee)
Cognitive processes associated with spatial orientation can use different reference frames: egocentric, centered on observer and allocentric, centered on objects in the environment. In this thesis, we use EEG to investigate the dynamics of brain processes accompanying spatial orientation based on these reference frames. Participants were instructed to estimate distances between objects or themselves and objects located in a virtual circular arena; this task was presented in both 2D and 3D displays. Task-related EEG changes were analyzed using a time-frequency analysis and event-related potential analysis of 128-channel EEG recordings. Through time-frequency analysis we found significant power differences in delta, theta, alpha, beta and gamma bands amongst the control, egocentric and allocentric testing conditions. We noted a decrease in alpha power in occipital and parietal regions, while a significantly stronger decrease was observed for the allocentric condition compared to both egocentric and control conditions. A similar pattern was also detectable for the beta band. We also report an increase in theta and delta power in temporal, fronto-temporal and lateral frontal regions that was significantly stronger for the egocentric condition compared to control and, in some electrodes, even...
Contribution of social dominance on performance in spatial cognitive tasks in pigeons
Janská, Iveta ; Landová, Eva (advisor) ; Sedláček, František (referee)
Diploma thesis generally compares individual success pigeons in spatial tasks of varying complexity (in a role that requires abstraction of visual stimuli representing spatial relationships on the touch screen using two different strategies and spatial search task the middle plate of a series of plates with different variants of location) with hierarchical status of males and group females. Specifically thesis compares individual success pigeons in spatial tasks of varying complexity. The hardest task requires a certain level of abstraction of visual stimuli representing spatial relationships using experimentally induced two strategies: mapping strategy or specific symbol association with a position in space. The role tests on the touch screen with the help of operant conditionings. Difficulty in various stages of growing, the last stage role does manage only some individuals. Conversely easier task in real space with a bird tasked with finding the midpoint between objects in different variants locations within the arena. The difficulty of the task is not growing, and it can solve some individuals who have not learned operant conditioning if the previous job. Performance in cognitive tasks could be affected by the hierarchical status of the animal in the group. Pigeons position in the hierarchy has...
Abstract tasks in birds - spatial vs non-spatial tasks
Janská, Iveta ; Landová, Eva (advisor) ; Vlček, Kamil (referee)
The aim of this thesis is to compare spatial cognitive tasks (radial maze and analogs, geometry and features) and non-spatial abstract cognitive task (concept formation and categorization, transitive inference) in birds. Because each of tasks have different testing methods they are compared according to method types in separate thematic groups, which are discussed each other. The extension of this thesis on theories derived from human psychology such as self-recognition, episodic-like memory, and theory of mind.
Hippocampal coding of positions of inaccessible objects
Hrůzová, Karolína ; Stuchlík, Aleš (advisor) ; Kudláček, Jan (referee)
The survival of the animals depends on their ability to memorize locations and to use behavioral spatial navigation strategies. The crucial structure for this type of behavior and memory is the hippocampus, by its ability to create a cognitive map. In this structure, there are specialized pyramidal cell called place cells. They respond by their complex firing pattern to specific animal's location in the environment. Even though many studies have investigated the role of hippocampal pyramidal cells in spatial navigation and object position discrimination, their function during inaccessible object position discrimination is not yet clarified. In our experiment, rats were trained in a behavioral task to discriminate between rewarded and nor- rewarded positions of object located in an inaccessible space. We investigated the role of individual hippocampal cells during this task by single neuron electrophysiology. The first aim of this study was to decide which of two configurations of objects presented on a computer screen during spatial object discrimination task rats can discriminate easily. The second aim is to show whether and how information about the position of inaccessible objects is represented in the hippocampus using single-neuron electrophysiology. We found out, that animals did not reach...
Spatial cognition of users of spoken Czech and Czech Sign Language: How cross-linguistic diversity affects non-linguistic thought
Jehlička, Jakub ; Chromý, Jan (advisor) ; Smolík, Filip (referee)
The thesis focuses on how different languages influence spatial cognition of their speakers, i. e., whether and how the differences in spatial language (linguistic representation of perspective, location, spatial scenes etc.) affect the non-linguistic spatial reasoning (orientation, spatial memory etc.). This issue has for a long time been a part of the studies of the relation between language and thouhgt under the flag of so called Sapir-Whorf hypothesis/Hypothesis of linguistic relativity. In the first half of the theoretical part of the thesis, I attempt to summarize the history of the concept of linguistic relativity since 1950s and to revise some critical claims about linguistic relativity by re-reading Whorf's works (chapter 2). The second half of the theoretical part (chapter 3) focuses in particular on the research of the interrelations between spatial thought and language. In section 3.1, I make a brief note on the notion of space in terms of cognitive linguistics. Section 3.2 provides an selective overview of the previous research of the crosslinguic spatial-cognitive diversity. Sections 3.3 and 3.4 connect the theoretical and the empirical part of the thesis. The research itself is presented in the chapter 4. It experimentally tests the hypothesis, that the language-specific...
Hippocampal coding of positions of inaccessible objects
Hrůzová, Karolína ; Stuchlík, Aleš (advisor) ; Kudláček, Jan (referee)
The survival of the animals depends on their ability to memorize locations and to use behavioral spatial navigation strategies. The crucial structure for this type of behavior and memory is the hippocampus, by its ability to create a cognitive map. In this structure, there are specialized pyramidal cell called place cells. They respond by their complex firing pattern to specific animal's location in the environment. Even though many studies have investigated the role of hippocampal pyramidal cells in spatial navigation and object position discrimination, their function during inaccessible object position discrimination is not yet clarified. In our experiment, rats were trained in a behavioral task to discriminate between rewarded and nor- rewarded positions of object located in an inaccessible space. We investigated the role of individual hippocampal cells during this task by single neuron electrophysiology. The first aim of this study was to decide which of two configurations of objects presented on a computer screen during spatial object discrimination task rats can discriminate easily. The second aim is to show whether and how information about the position of inaccessible objects is represented in the hippocampus using single-neuron electrophysiology. We found out, that animals did not reach...
EEG correlates of egocentric and allocentric distance estimates in virtual environment in humans
Kalinová, Jana ; Vlček, Kamil (advisor) ; Telenský, Petr (referee)
Cognitive processes associated with spatial orientation can use different reference frames: egocentric, centered on observer and allocentric, centered on objects in the environment. In this thesis, we use EEG to investigate the dynamics of brain processes accompanying spatial orientation based on these reference frames. Participants were instructed to estimate distances between objects or themselves and objects located in a virtual circular arena; this task was presented in both 2D and 3D displays. Task-related EEG changes were analyzed using a time-frequency analysis and event-related potential analysis of 128-channel EEG recordings. Through time-frequency analysis we found significant power differences in delta, theta, alpha, beta and gamma bands amongst the control, egocentric and allocentric testing conditions. We noted a decrease in alpha power in occipital and parietal regions, while a significantly stronger decrease was observed for the allocentric condition compared to both egocentric and control conditions. A similar pattern was also detectable for the beta band. We also report an increase in theta and delta power in temporal, fronto-temporal and lateral frontal regions that was significantly stronger for the egocentric condition compared to control and, in some electrodes, even...

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