Convergent evidence suggests that the dorsal medial prefrontal cortex (dmPFC) makes an important contribution to goal-directed action selection. The dmPFC is also part of a network of brain regions that becomes compromised in old age. It was hypothesized that during decision-making, some process of comparison takes place in the dmPFC between the representation of available actions and associated values, and that this process is changed with aging. These hypotheses were tested in aged and young adult rats performing a novel 3-choice, 2-cue decision task. Neuron and local field potential activity revealed that the dmPFC experienced different states during decision and outcome phases of the task, with increased local inhibition and oscillatory (gamma and theta) activity during cue presentation, and increased excitatory neuron activity (among regular firing neurons) at goal zones. Although excitatory and inhibitory activity appeared anti-correlated over phases of the decision task, cross-correlations and the prominent gamma oscillation revealed that excitation and inhibition were highly correlated on the millisecond scale. This "micro-scale" coupling between excitation and inhibition was altered in aged rats and the observed changes were correlated with changes in decision and movement speeds of the aged animals, suggesting a putative mechanism for age-related behavioral slowing. With respect to decision-making, both aged and young adult rats learned over multiple days to follow the rewarded cue in the 3-choice, 2-cue task. Support for the hypothesis that the dmPFC simultaneously represents alternative actions was not found; however, neuron activity selective for particular goal zones was observed. Interestingly, goal-selective neural activity during the decision period was more likely to take place on error trials, particularly on high-performing sessions and when rats exhibited a preference for a particular feeder. A possible interpretation of these patterns is that goal representations in the dmPFC might have sometimes overruled learned habits, which are likely to be involved in following the correct cue and which are known to be supported by other brain regions. These results describe fundamental properties of network dynamics and neural coding in the dmPFC, and have important implications for the neural basis of processing speed and goal-directed action.

The aim of this thesis is to determine the changes in BOLD signal of the human brain during various stages of reinforcement learning. In order to accomplish that goal two probabilistic reinforcement-learning tasks were developed and assessed with healthy participants by using functional magnetic resonance imaging (fMRI). For both experiments the brain imaging data of the participants were analysed by using a combination of univariate and model–based techniques. In Experiment 1 there were three types of stimulus-response pairs where they predict either a reward, a neutral or a monetary loss outcome with a certain probability. The Experiment 1 tested the following research questions: Where does the activity occur in the brain for expecting and receiving a monetary reward and a punishment ? Does avoiding a loss outcome activate similar brain regions as gain outcomes and vice a verse does avoiding a reward outcome activate similar brain regions as loss outcomes? Where in the brain prediction errors, and predictions for rewards and losses are calculated? What are the neural correlates of reward and loss predictions for reward and loss during early and late phases in learning? The results of the Experiment 1 have shown that expectation for reward and losses activate overlapping brain areas mainly in the anterior cingulate cortex and basal ganglia but outcomes of rewards and losses activate separate brain regions, outcomes of losses mainly activate insula and amygdala whereas reward activate bilateral medial frontal gyrus. The model-based analysis also revealed early versus late learning related changes. It was found that predicted-value in early trials is coded in the ventro-medial orbito frontal cortex but later in learning the activation for the predicted value was found in the putamen. The second experiment was designed to find out the differences in processing novel versus familiar reward-predictive stimuli. The results revealed that dorso-lateral prefrontal cortex and several regions in the parietal cortex showed greater activation for novel stimuli than for familiar stimuli. As an extension to the fourth research question of Experiment 1, reward predictedvalues of the conditional stimuli and prediction errors of unconditional stimuli were also assessed in Experiment 2. The results revealed that during learning there is a significant activation of the prediction error mainly in the ventral striatum with extension to various cortical regions but for familiar stimuli no prediction error activity was observed. Moreover, predicted values for novel stimuli activate mainly ventro-medial orbito frontal cortex and precuneus whereas the predicted value of familiar stimuli activates putamen. The results of Experiment 2 for the predictedvalues reviewed together with the early versus later predicted values in Experiment 1 suggest that during learning of CS-US pairs activation in the brain shifts from ventro-medial orbito frontal structures to sensori-motor parts of the striatum.

Action control arises from the interaction of two anatomically distinct decision-making systems, namely goal-directed and habitual behaviour. Goal-directed behaviour is characterized by the consideration of future choices and respective outcomes whereas habitual responding is driven by stimulus-response associations. Response inhibition is essential for goal-directed behaviour and deficits are shown in impulsivity. We administered an acute clinically relevant dosage of the commonly used serotonin reuptake inhibitor escitalopram to sixty-six healthy volunteers in a double-blind, randomized, placebo-controlled design. We administered a large task battery in order to study the effect of escitalopram in several cognitive functions including response inhibition, learning and affective processing. We found dissociate effects on cognitive aspects possibly mediated by distinct cortico-striatal loops. Acute escitalopram administration had a beneficial effect on action cancellation, one aspect of inhibitory control, without any effect on action restraint or waiting impulsivity. The treatment resulted in impaired performance in a probabilistic reversal-learning task and increased sensitivity to misleading feedback thus leading to maladaptive performance. An extra-dimensional set shift impairment during an attention set shift task and a tendency towards impaired instrumental learning discrimination were also observed in the escitalopram group. Our results are discussed in the context of well-documented effects of the dopaminergic system and suggestions of opponent interaction of serotonin and dopamine.

The World Health Organization (WHO) promotes physical activity as a primary way to maintain health, but many individuals do not participate in this health-promoting behavior. Despite the potential for public service announcements (PSAs) to communicate health information and promote behavioral change, no prior research on developing video PSAs to promote physical activity was found. The purpose of this quasi-experimental study was to examine how affective and information video PSAs for a public health campaign affect future levels of intention to engage in physical activity. The PSAs were developed and filmed specific for this study using the model of goal directed behavior (MGDB) as the foundation for PSA development. Participants were recruited to view PSAs with the message foci of empathy, fear, information, and combination messages to determine which focus area is perceived to be most persuasive for promoting physical activity. This research examined moderating effects of current physical activity habits related to the duration of physical activity and the covariance with stage of change readiness. Differences in perceived effectiveness between the different message foci were found with participants perceiving the empathy video as most effective, followed by combination, with fear and information being perceived as least effective. For participants who meet WHO recommendations for exercise activity, the PSA based on fear was most effective, with fear also being most effective for those participants right below that level of physical activity. Many participants (61%) had a positive affect while watching the four PSA videos. Social implications related to improving public health communication through video PSAs that effectively promote health behavior change.

The construction industry has had difficulty adopting project management software effectively and in a widespread manner. This thesis seeks to uncover common problems preventing the adoption of new software for construction project management, and to find a method to design more successful software. Construction project managers working at universities in the state of Georgia were selected as the specific group to study. To better define the functions of project management software, as well as uncover benefits both realized and anticipated, research was conducted. A Situation Awareness based approach was selected to result in proposing a prototype application that would specifically match the mental model of the study group. To define the mental model, a Goal Directed Task Analysis method was used by way of an online survey and in-person verification. In order to collect the survey data, a web based Goal Directed Task Analysis application was created and tested as a part of this thesis. Using the survey data, a proposed design for a prototype application was proposed. The application design was specifically made to fulfill the needs of project managers like those in the study group. The GDTA method proved effective in producing a software design. Recommendations to create and test the proposed prototype application are provided as a next step.

Το πρόβλημα εύρεσης συντομότερων διαδρομών είναι ένα από τα πιο θεμελιώδη προβλήματα μονοκριτηριακής βελτιστοποίησης σε δίκτυα. Σε αυτό το πρόβλημα αναζητείται η συντομότερη διαδρομή μεταξύ δύο δεδομένων σημείων ελαχιστοποιώντας ένα κριτήριο κόστους. Σε πολλές εφαρμογές ωστόσο, μας ενδιαφέρουν περισσότερα από ένα κριτήρια προς βελτιστοποίηση. Για παράδειγμα, στην εύρεση διαδρομών σε ένα οδικό δίκτυο με διόδια, μας ενδιαφέρει εκτός από την διανυμένη απόσταση και η ελαχιστοποίηση του χρόνου και του κόστους. Παρόμοια παραδείγματα βρίσκουμε και στον χώρο των δικτύων τηλεπικοινωνιών, όπου εξετάζονται κριτήρια όπως η καθυστέρηση, η πιθανότητα λάθους, ο αριθμός συνδέσμων και άλλα. Σε αυτές τις περιπτώσεις η καλύτερη λύση δεν μπορεί να οριστεί με μονοσήμαντο τρόπο, και συνεπώς καταφεύγουμε σε αντισταθμίσεις μεταξύ των παραγόντων, που είναι γνωστές ως σύνολο λύσεων κατά Pareto. Παρόλο που για το πρόβλημα μονοκριτηριακής εύρεσης συντομότερων διαδρομών υπάρχουν πολλοί αποδοτικοί αλγόριθμοι για την επίλυση του προβλήματος, το αντίστοιχο πολυκριτηριακό πρόβλημα είναι πολύ πιο σύνθετο. Μέχρι τώρα, αυτό το πρόβλημα έχει αποδειχθεί ότι είναι NP-πλήρες. Επιπλέον, έχει αποδειχθεί ότι το πλήθος των λύσεων σε αυτό το πρόβλημα αυξάνεται εκθετικά σε σχέση με το μέγεθος της εισόδου. Υπάρχουν δύο βασικές προσεγγίσεις επίλυσης τέτοιων προβλημάτων, όπου εξετάζονται πολλαπλά κριτήρια. α) Η πρώτη μέθοδος βρίσκει προσεγγιστικές λύσης κατά έναν ορισμένο παράγοντα. Οι προσεγγιστικές μέθοδοι δεν βρίσκουν απαραίτητα ακριβείς λύσεις, αλλά είναι σχετικά γρήγορες και προσφέρουν εγγύηση για το ποσοστό απόκλισης από την βέλτιστη λύση. β) Η δεύτερη μέθοδος χρησιμοποιεί ευρετικές βελτιώσεις για να επιταχύνει τους ήδη υπάρχοντες αλγορίθμους. Τέτοιες τεχνικές βρίσκουν ακριβείς λύσεις, και το ζητούμενο είναι να επιτευχθεί μια πολύ καλή χρονική απόδοση. Στην παρούσα διπλωματική εργασία επικεντρωνόμαστε στην δεύτερη μέθοδο, υποκινούμενοι από την μεγάλη ζήτηση πρακτικών εφαρμογών για εύρεση αποτελεσματικής και ακριβούς λύσης του προβλήματος συντομότερων διαδρομών υπό πολλαπλά κριτήρια. Πιο συγκεκριμένα, στην εργασία αυτή παρουσιάζουμε ένα ενοποιημένο πλαίσιο για την αποδοτική επίλυση αυτών των προβλημάτων. Προτείνουμε νέες μεθόδους ή βελτιώσεις των υπαρχόντων. Υλοποιήσαμε τις μεθόδους που παρουσιάζουμε συνοδεύοντάς τις με μια εκτενή πειραματική μελέτη πάνω σε δίκτυα ευρείας κλίμακας. / We present new implementations of heuristic algorithms for the solution of the multiobjective shortest path problem, using a new graph structure specifically suited for large scale road networks. We enhance the heuristics with further optimizations and experimentally evaluate the performance of our enhanced implementation on real world road networks achieving 10 times better performance with respect to the best previous study.

The role of language has been identified as crucial in the cognitive development of young children, and has been observed on different time-scales. In particular, the real-time verbal mediation of behaviour has been studied in the context of private speech use and self-regulation, pioneered by Vygotsky and continued by others who followed this line of research. However previous studies have mainly attempted to find correlations between speech and self-regulatory behaviour, but have been unable to capture the dynamic and real-time temporal interactions between these phenomena. Hence, without being able to carry out a contextual analysis of the actual instances of temporal co-occurrence between speech and behaviour, correlational analysis is limited in determining the various kinds of verbal mediation that children spontaneously employ as strategies during problem-solving and while exercising self-regulation. The current study proposes ‘temporal pattern analysis’ as an effective method of extracting significantly recurring patterns of task-relevant speech and goal-directed behaviour, as they repeatedly occur in a stream of naturalistic behaviour which may also contain other temporally random events. These recurring temporal patterns are then contextually analysed, considering the pragmatic content of the speech involved and the goal-directedness of the behaviour towards a specific goal of the episode. Goal-directed episodes of behaviour in eight typically-developing preschool children were video-recorded during their self-initiated activities in the classroom as well as during a problem-solving task held in a laboratory setting. The proposed method of temporal and contextual analysis was used to examine the role of both private as well as social speech in the verbal mediation of self-regulatory behaviour during goal-attainment. A Contextual Model of Verbal Mediation was proposed in the study to account for the diverse functions that both social and private speech perform during verbal mediation of one’s own and others’ behaviour in a goal-directed setting, depending on the specific social and task-related context. A dynamic framework of assessment of performance was developed in the study, to account for both successful attempts at self-regulation as well as failures of self-regulation. The study also attempted to determine any consistent group differences in the styles of verbal mediation employed by the children, across the classroom and the laboratory settings.

Personas (typanvändare) är ett populärt verktyg för interaktionsdesigners och gör det möjligt att, bland annat, uppfatta skillnader mellan en ofta stor mängd potentiella användare och därefter anpassa en design efter detta. Men hur användbart är detta verktyg om användarantalet är litet och deras mål i huvudsak styrs av deras identiska arbetsuppgifter? Interaktionsdesigners som vill försäkra sig om att de skapar användarvänliga applikationer bedriver ofta någon from av datainsamling och testning, från och med användare. Det finns flera kända metoder för analys av data som samlats in från kvalitativa studier. Det finns dock färre konkreta riktlinjer för vilka frågor man bör söka svar på under själva datainsamlingen. Detta varierar så klart kraftigt beroende på vilken kontext man befinner sig och någon universell lista med frågeställningar som alltid täcker in det man behöver kommer sannolikt aldrig att existera. Bardram (2000) och hans kollegor har dock sammanställt en checklista med frågeställningar de utvecklat under utvecklingen av ett nytt informationssystem för Danska sjukhus. Ett sådant system är väldigt komplext så det finns anledning att undersöka hur väl deras checklista fungerar för enklare system. I denna studie utvärderades nyttan av personas och Bardrams (2000) checklista som verktyg under ett designprojekt i en miljö med ett fåtal användare, vars uppgifter i huvudsak styrs av deras identiska arbetsuppgifter och komplexiteten i systemet är liten. Resultatet visade att personas är ett lämpligt verktyg trots likheten mellan användarna. Arbetet med att utveckla det som slutligen endast blev en persona gav författaren (tillika studiens interaktionsdesigner) ett sätt att fastställa att deras mål faktiskt var väldigt lika. Personan var grunden i utvecklingsarbetet som slutade med en lyckad design. Även Bardrams (2000) checklista visade sig vara ett bra stöd under studiens gång. Författaren ger dock förslag på två punkter att lägga till i denna checklista.

Counterfeit consumption is becoming widespread, developing into a problem of international significance. In an attempt to develop a refined understanding of the motivations and decision-making processes of consumers' deliberate counterfeit-consumption behavior, this empirical study not only integrates the theory of planned behavior and insights from self-regulatory theories, but also extends these theories by re-conceptualizing the relationships among key constructs with the inclusion of action desire. This research also introduces and integrates a new construct, namely consumers' Perceived Counterfeit Detection (PCD) by important others.Using a combination of qualitative and quantitative methods consisting of in-depth interviews and a self-administered paper questionnaire, this research empirically tested a proposed goal-striving model for deliberate counterfeit-consumption behavior, using structural equations modeling. Results demonstrated PCD's existence and supported a refined goal-striving model, based upon which effective strategies to decrease consumer's counterfeit consumption are discussed.

Autism Spectrum disorder (ASD) is a wide ranging developmental condition commonly recognised by impairments in social interaction, communication, repetitive behaviour and restricted interests. Deficits in imitation, sensory processing and motor control are also extensive, but conflicting findings mean a clear picture regarding the true nature of these is yet to be established. The aim of this thesis was to further investigate imitation with a specific focus on the effect of goals. It has been suggested that imitation occurs along two routes; a direct route for the imitation of meaningless actions i.e. goal-less, and a semantic route for meaningful or goal-directed actions. There is evidence to suggest that while individuals with ASD may have an impairment in goal-less imitation, goal-directed imitation is unaffected (Hamilton, Brindley & Frith, 2007). The experiments in the present work were based on the hypothesis that impaired goal-less imitation in ASD may be due to a problem with sensory motor integration in the direct visuomotor pathway for imitation (Tessari and Rumiati, 2004).The first experiment was conducted to ascertain whether movement kinematics differed between imitation during goal-directed and goal-less hand movements in a neurotypical control group. Participants observed and imitated hand movements of different speeds, while their movement was recorded with a motion sensor. Movement was modulated between the different speeds in the goal-less, but not goal-directed trials. These findings support the dual route model where visuomotor mapping occurs via the direct pathway during goal-less imitation but during goal-directed imitation there is greater reliance on representations of actions from long term memory.In experiment two, the same paradigm was employed, including additional movement types, and a group of adult individuals diagnosed with an ASD was compared to a control group. It was predicted that, unlike the control group, the ASD group would fail to modulate their movement in the goal-less condition, due to a disruption in the direct pathway. Eye movements were also recorded in this experiment, to ascertain if differences in gaze position or eye movements might influence the ability of the ASD group to imitate goal-less actions. The ASD group did not modulate their movement for goal-less imitation. In addition, the ASD group exhibited more goal-directed gaze, and less gaze toward the hand, than the control group. The ASD group also failed to maintain pursuit of the hand, which may have influenced the amount of information collected regarding the movement.The third study extended the investigation by introducing a training phase halfway through the experiment. Based on eye movement findings, it was hypothesised that drawing attention to the hand might increase the importance of the hand in goal-less trials, subsequently leading to increased tracking, and improved imitation. Perspective was also investigated to determine whether observing the action from an egocentric perspective would improve imitation. Movement modulation was not improved for either the post training or the egocentric condition. However, both training and egocentric viewing resulted in faster performance of movements while training also reduced the amount of movement variability; suggesting that these conditions made imitation easier. Findings strongly support the hypothesis that people with ASD are impaired in goal-less but not goal-directed imitation. These results are discussed in terms of bottom-up and top-down influences on imitation. The observed eye movement differences between the ASD and control group suggest eye movement abnormalities, and the finding that egocentric observation facilitates imitation indicates problems with visuospatial transformation during allocentric imitation. Finally, failure to pursue may be due to lack of attention to the hand movement, evidenced by no increase in pursuit after training. This thesis concludes with the suggestion that impaired goal-less imitation in ASD may result primarily from bottom-up low level visual processing and oculomotor control problems, combined with a high level attentional mechanism. Future studies need to address whether these are the primary causes of imitation difficulties, or whether there is a fundamental sensory motor integration deficit in ASD.