The current study sought to test the existence of a phenomenon known as sensory-specific satiety, in which attentional bias for food cues is specifically diminished for a consumed food, and the role of gender in such biases. In order to do so, the experiment used a version of the Flanker Task in which participants were shown image groups containing a target image and congruent or incongruent distracting flanker images. Participants (17 males, 22 females) were randomly assigned to consume one of two foods depicted in the flanker task (Ritz Bitz sandwiches or miniature Golden Oreos). Results did not support the idea of sensory-specific satiety, as we found a general reduction in reaction time rather than interactions in target/flanker congruency, suggesting that task performance was not driven by attentional bias to the food cues. However, there was an interesting interaction effect for session, consumption, and gender, such that women were faster than men for the consumed food post-satiety. Results may be explained by differences in motivation potentially caused by dissimilarities in dopamine levels. Additionally, results of the current experiment in combination with previous research could provide insight on gender differences in obesity.

The quantification of choice has been a major area of research for behavioural scientists for several decades. This is, in part, due to the discovery of the matching law (Herrnstein, 1961) which stipulates that relative response rates on concurrently available alternatives “match” the available relative reinforcement rates. This theoretical construct has been developed to describe response allocation in more complex situations, such as concurrent chains, and successfully describes both human and non-human behaviour. Typically, this phenomenon becomes evident when behaviour settles at an asymptote after several sessions of training where contingencies are held constant, and is often called “steady-state” behaviour. However, a fundamental question still remains: what causes matching – that is, what are the underlying momentary process(es) that produce matching? Researchers have suggested that what is necessary to answer this question is to take a molecular approach to the analysis of choice behaviour, thereby assessing choice in transition (Grace, 2002a). Recently, a new model of choice acquisition has been developed that appears to offer promise. It combines two separate mechanisms; a “winner-takes-all” categorical discrimination, and a linear-operator acquisition process (Grace & McLean, 2006). The initial results suggest this model could provide an alternative explanation for what underlies matching – that two separate processes are cooccurring in the acquisition of choice behaviour – allowing response allocation to be either linear or non-linear. This thesis extends the Grace and McLean model to include the situation of response strength ‘carrying-over’ from session to session to describe the process of acquisition gradually accumulating with experience. Moreover, additional assumptions have been added to describe temporal phenomena 2 and presumed discounting of previous experience on current choice behaviour. A steady-state version of the extended model was derived and, when fitted to published data sets, describes choice behaviour equally well when compared to existing models of steady-state choice. As a consequence of these additions, the Extended Decision Model (EDM) predicts a unique response allocation pattern – choice behaviour follows a bitonic function when initial-link durations were increased and the terminallink delays were held constant. The results from experiments presented in this thesis support this prediction, whilst steady-state analyses found the EDM was parameter invariant – differences between parameters from two schedule types across several archival data sets were non-significant, while existing steady-state models had significant differences. These findings provide further support for the claim that the EDM and the Decision Model (DM) mechanisms provide unique and accurate descriptions of the molecular processes governing choice behaviour. Moreover, the implication from these results is that the underlying assumption of the EDM and DM – that choice is determined by the propensity to respond rather than conditioned reinforcement – appears to have further foundation. This challenges the assumptions of existing models of choice behaviour and presents the possibility that probabilistic approaches are perhaps more appropriate for describing response allocations than discrete estimates of relative value when contingencies change.

Children are often involved in the legal system as victims of maltreatment, and their disclosure of adult wrongdoing is necessary to initiate effective legal responses and protect them from continued abuse. However, external pressures and children's perceptions of the consequences of truth-telling (e.g., punishment, removal from the home) may result in the delay of disclosure or failure to disclose altogether. Research examining techniques for promoting children's truth-telling has almost exclusively relied on explicit requests to tell the truth (e.g., a promise, reassurance, assessments of conceptual knowledge and moral discussions), and the success of these techniques has varied. The present study examined the benefit of priming honesty (i.e., indirectly or non-consciously activating the goal of honesty) on children's disclosure of an adult's transgression. One-hundred fifteen 6- to 9-year-olds (M age = 7.47 years) participated in a first aid/safety event during which an adult (mother or stranger) engaged the child in play with a box of forbidden puppets, broke a puppet that was designed to break, and requested that the child keep it a secret. Before responding to questions about the puppets, children were either (1) primed for the goal of honesty (prime condition), (2) asked to promise to tell the truth (oath condition), or (3) not provided with any further instructions or information (control condition). Then, children were asked open-ended, direct, and suggestive questions about whether they or the adult touched, played with, or broke any puppets. Regression analyses revealed that children’s truthful disclosures to direct questions increased when children witnessed a stranger transgressing rather than their mother. However, children’s truthful disclosures across the question types did not differ by age or when a prime relative to a promise to tell the truth was used. Results advance our understanding of how children disclose negative events and the effectiveness of different techniques (including a novel technique) in encouraging children’s true disclosures of a parent or stranger’s transgression.

The effectiveness of a teaching progression to teach three “Olympic” exercises and improve gross motor coordination was evaluated with four children (3 boys, 1 girl) diagnosed with autism spectrum disorder (ASD). A multiple baseline design across children and within children across activities was used to evaluate the effectiveness of the teaching progression used to teach the physical exercise program, which consisted of three “Olympic” events (long jump, 50 foot dash, and a relay race). Results showed all four participants learned the three “Olympic” exercises, with all four participants mastering at least one of the three exercises. Two participants mastered all three “Olympic” exercises. Additionally, all four participants experienced a significant improvement in gross motor coordination. A posttest follow-up was done one week after the participant finished the third test phase, or mastered the final exercise. These results show that physical modeling, focused feedback, and focused physical modeling can be successfully used to teach children with ASD how to perform physical exercises, as well as the fact that learning how to perform, and actually performing, physical exercises increased gross motor coordination in children with ASD.

The proposed study aims to investigate the effects of culture and mass media images of female bodies in an active or static pose on mood, body idealization, and body dissatisfaction. Participants included female students with Chinese heritage culture (age M =21.26, SD =2.5) and 130 female students who identified with American heritage culture (age M =20.82, SD =1.2). Participants filled out an online survey distributed through Qualtrics, which includes a pre-and-post negative affect and body satisfaction measure. They were randomly assigned to one of three conditions, viewing posing models, models in active poses, or scenery images. Consistent with previous findings, the current study results showed a main effect of body conceptualization on participants’ body dissatisfaction and choice of ideal body image. Viewing pictures of models either in static or active poses led to significant increase in body dissatisfaction and increased the likelihood of choosing skinnier ideal body image as compared to the control condition. However, there was no main effect of culture and interaction between culture and body conceptualization. Future research is needed to explore other variables that might moderate the association between body conceptualization and participants’ psychological outcomes after exposing to body ideals in mass media presentations.

Cocaine users display impaired inhibitory control. The influence of cocaine-related stimuli on inhibitory control has not been assessed. The Attentional Bias-Behavioral Activation (ABBA) task uses cocaine and neutral images as cues to determine if drug-related images impair inhibitory control in cocaine users. This dissertation was designed to assess the influence of cocaine images on inhibitory control in cocaine users through the conduct of studies designed to address four aims. The first aim was to demonstrate that cocaine users display impaired inhibitory control following cocaine images compared to neutral images on the ABBA task. This was accomplished through the conduct of two experiments. The first experiment piloted the ABBA task and cocaine users completed the cocaine go (n = 15) or neutral go condition (n = 15) of the task. The second experiment consisted of two studies designed to develop a within-subjects methodology for using the ABBA task. In the first study, cocaine users completed either the cocaine go (n = 20) or neutral go (n = 20) condition of the ABBA task and all participants also completed the Cued Go/No-Go task, with geometric shapes as cues. In the second study, cocaine users (n = 18) completed the cocaine go condition of the ABBA task and a modified version of the ABBA task with all neutral images as cues to further refine a possible within-subjects methodology. The second aim was to demonstrate that inhibitory failures occur most often when cues are presented for short compared to longer durations of time. Data collected during other protocols (n = 91) were combined to investigate the influence of stimulus onset asynchrony (SOA; i.e., the amount of time a cue is presented before a target indicated a response should be executed or withheld) on inhibitory control following cocaine-related and neutral cues on the ABBA task. The third aim was to demonstrate impaired inhibitory control following cocaine images on the ABBA task is specific to cocaine users. Cocaine users (data collected in the second experiment of the first aim) and non-using control participants (n = 16) completed the cocaine go and all neutral conditions of the ABBA task and the Cued Go/No-Go task. The fourth aim was to demonstrate the feasibility and acceptability of inhibitory control training to cocaine-related stimuli with cocaine users. A small pilot clinical trial was conducted and cocaine users were randomly assigned to complete inhibitory control training to cocaine images or geometric shapes. Cocaine images impaired inhibitory control on the ABBA task, as demonstrated by an increased proportion of inhibitory failures in the cocaine go condition compared to the neutral go condition in Experiments 1, 2, and 4. The proportion of inhibitory failures following cocaine images in Experiment 4 was increased at short (i.e., 100, 200) compared to long SOAs. Cocaine images also impaired inhibitory control compared to the Cued Go/No-Go Task in Experiment 2, however there were no differences in the proportion of inhibitory failures between the cocaine go and all neutral conditions of the ABBA task. There were no differences between cocaine users and controls in Experiment 3 for the proportion of inhibitory failures on the ABBA or Cued Go/No-Go tasks, but controls responded faster indicating a speed/accuracy trade off occurred in the control group. Inhibitory control training as an approach to improve treatment outcomes is feasible, as indicated by attendance and accuracy on the training task, and participants rated the overall procedure as satisfactory in Experiment 5. A better understanding of inhibitory control in the presence of cocaine related cues could be crucial to better understand how drug cues contribute to the risk for relapse and the continued use of drugs because both occur in the presence of drug cues.

The present study examines the relationships between recognition and recall accuracy of faces, and recognition and recall accuracy of objects. Secondly, this study examines the influence of weapon presence on description and identification accuracy, and whether encoding time moderates the effect. 713 participants watched an image that was either displayed for five seconds or twenty seconds, and either included a weapon or no weapon. Subsequently, they were asked to give descriptions of what they saw before viewing a lineup that either included the perpetrator or was made up of innocent suspects. Results indicated that witnesses’ description accuracy of the crime scene had little or no predictive abilities with regards to their facial identification accuracy. Secondly, there was a weapon focus effect found for faces but not for objects. Furthermore, this effect was eliminated at long encoding times. Finally, increasing encoding time improved recognition of objects, but not faces. Results suggest that prior inaccuracy on one aspect of testimony is not necessarily indicative of subsequent inaccuracy on another aspect of testimony. This finding has implications for how jurors and judges should evaluate witness testimony when assessing credibility in the courtroom.

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Choosing a course of action in our daily lives requires an accurate assessment of the associated risks as well as the potential rewards. The present two studies investigated the mechanism of how reward and risk level influence the motor decisions of speeded actions (Chapter 2) and its neural dynamics (Chapter 3) by focusing on the beta band (15-30 Hz) oscillation patterns reflected in the EEG signals. Participants performed a modified version of the Go-NoGo task, in which they earned reward points based on the speed and accuracy of response. On each trial, the reward points at stake (120 vs. 6) and the probability that a Go signal would follow (Go-probability) were presented prior to a Go/NoGo signal (Trial Information Period). The behavioral results (from both Chapters 2 and 3) showed that larger amount of rewards can motivate people to respond faster, and this effect was modulated by the assessed risk, suggesting that decisions for actions are based on a systematic trade-off between rewards and risks. The EEG data showed that motor beta oscillations from the two studied brain regions reflected different levels of motivation towards a motor response across different reward and risk levels. Specifically, the lower beta power associated with higher reward and lower risk level. Collectively, the results provide a mechanistic understanding of how motivational cues are translated into action outcomes via modulating patterns of brain oscillations.