A fuzzy cognitive map (FCM) is made up of factors and direct impacts. In graph theory, a bipolar weighted digraph is used to model an FCM; its vertices represent the factors, and the arcs represent the direct impacts. Each direct impact is either positive or negative, and is assigned a weight; in the model considered in this thesis, each weight is interpreted as the probability of the impact. A directed walk from factor F to factor F' is interpreted as an indirect impact of F on F'. The probabilistic transitive closure (PTC) of an FCM (or bipolar weighted digraph) is a bipolar weighted digraph with the same set of factors, but with arcs corresponding to the indirect impacts in the given FCM. Fuzzy cognitive maps can be used to represent structured knowledge in diverse fields, which include science, engineering, and the social sciences. In [P. Niesink, K. Poulin, M. Sajna, Computing transitive closure of bipolar weighted digraphs, Discrete Appl. Math. 161 (2013), 217-243], it was shown that the transitive closure provides valuable new information for its corresponding FCM. In particular, it gives the total impact of each factor on each other factor, which includes both direct and indirect impacts. Furthermore, several algorithms were developed to compute the transitive closure of an FCM. Unfortunately, computing the PTC of an FCM is computationally hard and the implemented algorithms are not successful for large FCMs. Hence, the Reduction-Recovery Algorithm was proposed to make other (direct) algorithms more efficient. However, this algorithm has never been implemented before. In this thesis, we code the Reduction-Recovery Algorithm and compare its running time with the existing software. Also, we propose a new enhancement on the existing PTC algorithms, which we call the Separation-Reduction Algorithm. In particular, we state and prove a new theorem that describes how to reduce the input digraph to smaller components by using a separating vertex. In the application part of the thesis, we show how the PTC of an FCM can be used to compare different standpoints on the issue of work-integrated learning.

In a large scale environment humans rely on their mental representations cognitive maps to solve navigational problems. To approach the understanding of how humans acquire, process, and utilize information from the environment, three groups of participants in this study performed several experiments associated with finding their way in a previously unknown environment. Experimental tasks included route retracing, pointing to previously visited locations, and a questionnaire regarding wayfinding strategies and cognitive map development. Each of three groups of participants was in one of three unique conditions: 1. learning and retracing with navigational landmarks indicating right and left turns at decision points; 2. during route retracing only generic landmarks were present at decision points (landmarks indicating left and right were present during learning but replaced during retracing); and 3. no landmarks were present during route retracing (landmarks indicating left and right were present during learning but removed before retracing started). Results supported the hypothesis that during the initial stages of visiting an unknown environment we build metric knowledge together with non-metric knowledge associated with the broad categories of landmark and route knowledge. In addition, the environment plays an important role in wayfinding performance and that characteristics of the environment contribute differently to the development of our cognitive map. Last but not least, the strategies humans use to solve wayfinding problems in a novel environment are not based on an individual type of environmental knowledge; in fact, we switch between different types of environmental knowledge when necessary. Shifting between strategies appears to be from more familiar environmental knowledge to less familiar knowledge. In particular, participants from group 3 (no landmarks during the retracing period) were more likely to walk off-route during retracing but exhibited more accurate metric knowledge of the environment. Based on the results of this experiment, they combined route- and survey-based strategies in wayfinding and switched from the most familiar knowledge to a less familiar strategy.

In a large scale environment humans rely on their mental representations cognitive maps to solve navigational problems. To approach the understanding of how humans acquire, process, and utilize information from the environment, three groups of participants in this study performed several experiments associated with finding their way in a previously unknown environment. Experimental tasks included route retracing, pointing to previously visited locations, and a questionnaire regarding wayfinding strategies and cognitive map development. Each of three groups of participants was in one of three unique conditions: 1. learning and retracing with navigational landmarks indicating right and left turns at decision points; 2. during route retracing only generic landmarks were present at decision points (landmarks indicating left and right were present during learning but replaced during retracing); and 3. no landmarks were present during route retracing (landmarks indicating left and right were present during learning but removed before retracing started). Results supported the hypothesis that during the initial stages of visiting an unknown environment we build metric knowledge together with non-metric knowledge associated with the broad categories of landmark and route knowledge. In addition, the environment plays an important role in wayfinding performance and that characteristics of the environment contribute differently to the development of our cognitive map. Last but not least, the strategies humans use to solve wayfinding problems in a novel environment are not based on an individual type of environmental knowledge; in fact, we switch between different types of environmental knowledge when necessary. Shifting between strategies appears to be from more familiar environmental knowledge to less familiar knowledge. In particular, participants from group 3 (no landmarks during the retracing period) were more likely to walk off-route during retracing but exhibited more accurate metric knowledge of the environment. Based on the results of this experiment, they combined route- and survey-based strategies in wayfinding and switched from the most familiar knowledge to a less familiar strategy.

The hippocampus is critical for the encoding and retrieval of episodic memories. During ongoing experience, the hippocampus exhibits activity patterns related to the current spatiotemporal context. How hippocampal firing patterns relate to the representation of mental maps important for behavioral and cognitive processes is still an open question. Here a series of experiments aimed to test how the hippocampus represents the spatiotemporal context of ongoing experience. Extracellular recordings from the dorsal CA1 region of the hippocampus were collected from rats engaged in a blocked serial reversal object-association task. Behaviorally, rats did not utilize the temporal segregation between task blocks as a way to correctly match object valence and rather treated each block of trials as separate episodes. This lack of an alternating context was further uncovered in the neural coding of the rat’s hippocampal firing patterns. Furthermore, gradual drift in the hippocampal ensemble representation of experience was discovered, correlating with the temporal duration of the task and not the blocked organization of the behavioral paradigm. In the next two experiments, extracellular recordings from dorsal CA1 were collected from rats traversing a linear track environment, with different environmental manipulations. During variable starting location recording sessions, it was found that positional coding by the hippocampal population was relative to starting location and that place field allocation was biased towards the reference frame at the start of the journey, demonstrating that hippocampal place fields are not uniformly distributed and express compressed activity patterns referenced to the beginning point of trajectories. During blocked manipulation of lighting condition, individual units showed preference to specific lighting conditions and the hippocampal population rapidly remapped between lights ‘ON’ and lights ‘OFF’ blocks of trials, suggesting that hippocampal maps of space are not solely governed by internal dynamics and that alterations in sensory input can modify hippocampal motifs of ongoing experience. Overall, the findings of the three experiments further our understanding of how the hippocampus represents ongoing experience, highlighting the role of temporal drift as well as demonstrating how both external and internal stimuli and frames of reference coalesce into a comprehensive cognitive map of experience.

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Cognitive Map Theory (O’Keefe & Nadel, 1978) posits that spatial behavior can reflect locale or taxon strategies. Only locale strategies depend on cognitive maps, and learning recruited by these strategies is unlike associative learning (e.g., Rescorla & Wagner, 1972; Mackintosh, 1975), which is prevalent in the taxon system. Associative learning phenomena like the blocking effect (Kamin, 1969) should therefore not occur during acquisition of cognitive maps. Contrary to this prediction, blocking effects have been demonstrated in spatial learning (e.g., Biegler & Morris, 1999; Chamizo, Sterio, & Mackintosh, 1985; Hamilton & Sutherland, 1999), and have been generally interpreted as evidence against cognitive map theory. Here we provide evidence suggesting that taxon and not locale strategies were promoted in these experiments, and we ask which factors determine whether taxon or locale strategies control spatial behavior in a computer-implementation of a widely used spatial task (Morris Water Maze; Morris, 1981). We isolated two factors relevant for spatial strategy choice in human spatial learning that are both related to the individual’s preexisting knowledge, namely conceptual knowledge about the distal cues, and knowledge about the task affordances. The blocking effect was used as an index for locale or taxon learning. We found that taxon strategies were more likely for abstract distal cues, while concrete cues promoted locale strategies – blocking was present for the former, but not the latter. When subjects were aware that the distal cues predicted locations, locale, and not taxon strategies were recruited, such that blocking was not observed. Spatial strategy choice appears to be largely driven by interindividual differences, and can therefore not be easily predicted a priori. Our findings cannot be explained by associative learning theories, but provide strong support for cognitive map theory and the position that multiple behavioral systems exist in the brain.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Brent Chamberlain / Landmarks are universal components of human urbanization. We are a species driven to mark the land with symbolic structures and craft meaning in our built environments. From ancient wonders such as Stonehenge to modern icons like the St. Louis Arch, we have been designing landmarks since the dawn of civilization. Cities, towns, and neighborhoods incorporate landmarks as elements of cultural expression and tools for navigation. Individuals use landmarks as reference points to create an internal cognitive map, permitting more efficient navigation throughout a city and contributing to a heightened sense of place. To aid in research regarding the role of landmarks on cognitive maps and place-identity, we have designed a novel testing paradigm in which subjects wear a virtual reality (VR) head-mounted display (HMD) and traverse a hypothetical urban environment using a gaming controller. The virtual environment (VE) features a gridded street network measuring 5x5 blocks and guides subjects along a fixed route through residential, park, commercial and industrial districts. Along this fixed route, subjects are exposed to ten distinct landmarks. After navigating the VE, subjects are tasked with delineating their perceived route, landmark locations, and district boundaries through map drawing tasks on grid paper as well as a scene recognition task. The most significant finding revealed landmark configuration accuracy to be highly correlated with performance on the route recall and moderately correlated with performance on the scene recognition task. This suggests that, regardless of the landmark type, individuals who more precisely recalled landmark locations also navigated the route and identified scenes more accurately. Landscape and urban planners can leverage these findings to advocate for the strategic inclusion of landmarks throughout an urban fabric, which we term Landmark Configuration Plans (LCP).

This thesis argues the case for the use of a pattern language based on the basic features of the programming language used in instruction for the teaching of programming. We believe that the difficulties that novices are known to have encountered with the task of learning to program ever since the inception of computers derive from a basic misfit between the language used to communicate with a computer, the programming language, and the way that humans think. The thrust of the pattern language idea is that patterns are the essential element in understanding how the mind words in that they are the source of that relationship that we call `meaning'. What an entity or event `means' to us derives from the effect that it has on us as living biological beings, a relationship that exists in the `real world', not from any linguistic relationship at the symbolic level. Meaning, as a real world relationship, derives from the patterns of interactions that constitute being. The meaning that an entity has for an individual is more than can be expressed in a formal definition, definitions are matters of agreement, convention, not the pattern of experience that the individual has acquired through living. What is missing for a novice in any skill acquisition process is meaning, the pattern of experience. All that we can give them using a formal linguistic system like a programming language is definitions, not meaning. Pattern language is the way that we think because it exists at that fundamental level of experience as living beings. The patterns of experience become the patterns of thought through recurrence, not through definition. But this takes time, so in presenting new material to a person trying to learn, we have to present it in the form of a pattern language, the 'cognitive map' that drives the problem solving process. Creativity is always a function of combining ideas, what is really being created is new meaning, not a program, or a house, or a poem, or a sculpture - these things are mere implementations of meaning. Ultimately meaning can derive only from experience, the pattern of life around us, so creativity is the language of experience, pattern language. The mind is the product of experience, creativity its modus operandi.

In order to evaluate a project as successful or not, initially, the questions of &ldquo / what are the factors affecting the success&rdquo / and &ldquo / according to whom and which criteria should the success be measured&rdquo / should be answered. Both the factors and their influences vary depending on a project&rsquo / s specific characteristics, different environmental factors affecting it, and different parties involved. These factors are not independent of each other and the interrelationship between them should be investigated as a whole in order to model the project success. Moreover, parties involved in a project usually have different objectives and the performance indicators used to measure project success differ according to company priorities, preferences and attitudes. Thus, there exists a need to develop a project success model that contains the interrelationships between factors such as risks, decisions, and strategies, project success criteria, objectives and the relations of the factors with the objectives. A cognitive map (CM) is a strong visual tool to reflect the beliefs and knowledge of people about a situation or domain, identifying the causes, effects and the relations between them. This qualitative technique being enhanced by quantifiable properties makes it appropriate to be utilized to model the project success. As a result, the objective of this study is to demonstrate the application of CMs as a powerful tool for modeling project success. It is hypothesized that CMs can be effectively used to model the factors affecting success of a construction project, to reflect the interrelations between project success factors, to demonstrate the different objectives of parties involved in a project and show how the project success can be defined differently, by different parties. This technique is applied to a real construction project realized in Turkey. CMs of two consortium contractors and client organization involved in the project are constructed and the differences between the perceptions of three parties are revealed by content and structural analyses. Finally, the benefits and shortcomings of using CMs for modeling project success are discussed by referring to case study findings.

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