Since the introduction of the American Academy of Pediatrics Back to Sleep Campaign infants have not met the recommendation to “incorporate supervised, awake “prone play” in their infant’s daily routine to support motor development and minimize the risk of plagiocephaly”. Interventions are needed to increase infants’ tolerance for prone position and prone playtime to reduce the risk of plagiocephaly and motor delays. Associative learning is the ability to understand causal relationship between events. Operant conditioning is a form of associative learning that occurs by associating a behavior with positive or negative consequences. Operant conditions has been utilized to encourage behaviors such as kicking, reaching and sucking in infants by associating these behaviors with positive reinforcement. This dissertation is a compilation of three papers that each represent a study used to investigate a potential play based interventions to encourage prone motor skills in infants. The first paper describes a series of experiment used to develop the Prone Play Activity Center (PPAC) and experimental protocols used in the other studies. The purpose of the second study was to determine the feasibility of a clinical trial comparing usual care (low tech) to a high-tech intervention based on the principles of operant conditioning to increase tolerance for prone and improve prone motor skills. Ten infants participated in the study where parents of infants in the high tech intervention group (n=5) used the PPAC for 3 weeks to practice prone play. Findings from this study suggested the proposed intervention is feasible with some modifications for a future large-scale clinical trial. The purpose of the third study evaluated the ability of 3-6 months old infants to demonstrate AL in prone and remember the association learned a day later. Findings from this study suggested that a majority of infants demonstrated AL in prone with poor retention of the association, 24 hours later. Taken together these 3 papers provide preliminary evidence that a clinical trial of an intervention is feasible and that associative learning could be used to reinforce specific prone motor behaviors in the majority of infants.

The association of olfactory information with a resource is broadly known as olfactory-based associative learning. From an ecological perspective, associative learning can reduce search time for resources and fine tune responses to changing biotic and abiotic factors in a variable environment, which in mosquitoes has implications for pathogen transmission and vector control strategies. The purpose of this dissertation was to examine the ability for olfactory-based associative learning across the major life history domains of mosquitoes. Six different experiments comprise this dissertation. The first was to evaluate the response of mosquitoes following conditioning to 5, 10 or 50% sucrose concentrations with individual level mosquito conditioning and testing and introduction of statistical analysis with binary logistic regression. Mosquitoes did not respond in a dose dependent manner with respect to positive response to target odors following conditioning. This effect appears to be related to the mosquitoes' prior exposure to sugar as those exposed to 10% sucrose before conditioning did not prefer 50% sucrose but significantly fewer chose 5% sucrose. In an evaluation of host associated odors and second blood meal choice by females using a dual-choice olfactometer no significant effects were observed. The lack of significance may have been due to insufficient sample sizes, problems with odor collection or physiological state of mosquitoes. Effects of predatory mosquitofish on larval development and female oviposition choice were evaluated by rearing in separated habitats under three different treatments followed by an oviposition choice assay. Females did not prefer their natal habitat or avoid predators but chose substrate that had contained mosquitofish fed conspecific larvae. Mosquitofish affected larval development with acceleration in treatments with mosquitofish fed Tetramin® and delayed pupation in treatments with mosquitofish fed conspecific larvae. Mosquito memory length was evaluated by conditioning and testing at six time intervals from colony and field populations at two ages. Younger mosquitoes showed higher levels of positive response after conditioning at all time intervals except the longest (24h). Finally the olfactory-based associative learning ability of Anopheles cracens was evaluated. Significant evidence for learning was observed in males but not females at a memory length interval of 24h.

<p>In the present study, we examined the predictions of an attentional-associative model (Schmajuk, Lam, & Gray Journal of Experimental Psychology: Animal Behavior Processes, 22, 321-349, 1996) regarding the effect of attentional manipulations on both discrete and contextual conditioned inhibitors.</p><p>The SLG model assumes that non-reinforced presentations of an inhibitory conditioned stimulus (CS) do not decrease its inhibitory associations. However, the model predicts that extended presentations will decrease attention to the inhibitor, thereby, decreasing both the expression of its inhibitory power in a summation test and the rate of acquisition in a retardation test. The model also predicts that subsequent presentations of the inhibitory CS with a novel CS will increase both its inhibitory power in a summation test and the rate of acquisition in a retardation test. Using a predictive learning design in humans, Experiment 1 examined the predictions involving the summation tests, whereas Experiments 2 and 3 examined the predictions involving the retardation tests. Experimental results were in agreement with the predictions of the model. </p><p>The SLG model also predicts that a salient extinction context (CX) becomes inhibitory and prevents extinction of the excitatory CS-unconditioned stimulus (US) association. Although some data seem to contradict that prediction (e.g., Bouton and King, 1983, Bouton and Swartzentruber, 1986, 1989), Larrauri and Schmajuk (2008) indicated that the CX might not appear inhibitory in a summation test because attention to the CX decreases with many but not few extinction trials. In a human predictive learning experiment, we confirmed the model's predictions that the inhibitory power of the extinction CX can be detected after a few extinction trials when attention to the CX is still high, but not after many extinction trials once attention to the CX has decreased (Experiment 4), and even after many extinction trials by presenting novel CSs to increase attention to the unattended CX (Experiment 5). Furthermore, using an eye-tracker, we confirmed the model's explanation of Experiment 4 results by showing decreased overt attention to the CX after many but not after few extinction trials (Experiment 6).</p><p> Importantly, the view that the extinction CX becomes inhibitory allows the model to explain spontaneous recovery (because attention to the excitatory CS increases before attention to the inhibitory CX), renewal (because the inhibition provided by the extinction CX disappears), and reinstatement (the inhibitory CX becomes neutral or excitatory), as well as a very large number of other experimental results related to extinction. Based on the prediction of the SLG, model the implications of our results for the treatments of anxiety disorders were discussed.</p> / Dissertation

Retrospective revaluation— learning about implied but unpresented cues— poses one of the greatest challenges to classical learning theories. Whereas theorists have revised their models to accommodate revaluation, the empirical reliability of the phenomenon remains contentious. I present two sets of experiments that examine revaluative learning under different but analogous experimental protocols. Results provided mixed empirical evidence that is difficult to interpret in isolation. To address the issue, I apply two computational models to the experiments. An instance-based model of associative learning (Jamieson et al., 2012) predicts retrospective revaluation and anticipates participant behaviour in one set of experiments. An updated classical learning model (Ghirlanda, 2005) fails to predict retrospective revaluation, but anticipates participant behaviour in the other set of experiments. I argue that retrospective revaluation emerges as a corollary of basic memorial processes and discuss the empirical and theoretical implications.

No description available.

Retrospective revaluation— learning about implied but unpresented cues— poses one of the greatest challenges to classical learning theories. Whereas theorists have revised their models to accommodate revaluation, the empirical reliability of the phenomenon remains contentious. I present two sets of experiments that examine revaluative learning under different but analogous experimental protocols. Results provided mixed empirical evidence that is difficult to interpret in isolation. To address the issue, I apply two computational models to the experiments. An instance-based model of associative learning (Jamieson et al., 2012) predicts retrospective revaluation and anticipates participant behaviour in one set of experiments. An updated classical learning model (Ghirlanda, 2005) fails to predict retrospective revaluation, but anticipates participant behaviour in the other set of experiments. I argue that retrospective revaluation emerges as a corollary of basic memorial processes and discuss the empirical and theoretical implications.

The present research sought to describe and explain age related changes to associative learning processes. Eleven experiments were conducted using a human conditional learning paradigm. Background data on health, lifestyle, and cognitive ability were collected and used as predictor variables in multiple regression analyses. Experiments 1 to 8 were formative, and found that older participants showed an overall age related decline in learning ability exacerbated by the number of stimuli and outcomes used, and the concurrent presentation of different problem types. Configural models of learning (e.g. Pearce, 1994, 2002) best predicted young participants’ learning whereas older people’s learning was more consistent with elemental models (e.g. Rescorla-Wagner, 1972), suggesting an age related change in generalisation processes. Those who learned problems better were also more likely to be able to articulate a rule that had helped them learn the problem. Age itself was the most predominant predictor of accuracy in these experiments. Experiments 9, 10, and 11 were multiple stage experiments that looked at the extent of pro- and retro-active interference in learning. Experiments 9 and 10 used easy and hard HCL problems to examine the role of rule induction in learning. Older participants who had learned initial discriminations better were more prone to pro-active interference in both experiments, the extent of which was predicted most reliably by fluid intelligence. Rule learning had a profound effect on participants’ predictions during the unreinforced test stage. In Experiment 9 (Easy-Hard) younger participants suffered from more retroactive interference than older people. This pattern was far less pronounced in Experiment 10, (Hard-Easy) suggesting that problem order affected the way participants generalised from rule-based knowledge. This observation is inexplicable by associative learning theories, and explanation may require a problem solving approach. Experiment 11 examined feature-based generalisation. Again older participants suffered more proactive and retroactive interference and elemental theories predicted their responses best, whereas younger participants responses were consistent with configural models of learning. In this instance, resistance to pro- and retro-active interference was predicted by fluid intelligence. Overall the research concluded that there is a demonstrable, complexity dependent change in associative learning processes in later life. It appears that humans have an increasing tendency to rely on elemental, rather than configural processes of generalisation in later life, and this leads to overgeneralisation between stimuli and an inability to resist pro- and retroactive interference in learning. This may be as a result of an inhibitory or source monitoring failure as a consequence of atrophy in the frontal lobes of the brain, although some of the learning deficits are explicable through mnemonic decline.

The experiments reported in this thesis were conducted to examine the effects of executive-control and associative-learning processes on performance in conventional executive-control paradigms. For this purpose, I developed comparative task-switching and response-inhibition paradigms, which were used to assess the performance of pigeons, whose behaviour is presumably based purely on associative processes, and of humans, whose behaviour may be guided by executive control and by associative processes. Pigeons were able to perform accurately in the comparative paradigms; hence, associative-learning processes are sufficient to account for successful performance. However, some task-specific effects that can be attributed to executive-control processes, and which were found in humans applying executive control, were absent or greatly reduced in pigeons. Those effects either reflect the mental operations that are performed to ensure that a specific set of stimulus-response-contingencies is applied and any contingencies belonging to a different set are suppressed, or reflect mental preparations for the possibility that the requirement to execute a certain response suddenly changes. In particular, in Chapter 3, it is shown that the benefits of repeatedly applying the same set of stimulus-response contingencies (or, in reverse, the costs of switching from one set to another) do not apply when Pavlovian processes dominate learning, which is likely the case for pigeons. Furthermore, as shown in Chapters 4 and 5, the behavioural effects of preparing for an unpredicted change in response requirements appeared to be absent when behaviour was based purely on associative processes. Instead, associatively mediated performance was primarily influenced by the stimulus-response contingencies that were effective in each paradigm. Repeating the same response in consecutive trials facilitated the performance of pigeons and associatively learning human participants in the task-switching paradigms, and performing a particular Go response increased the pigeons' likelihood of executing that response in the following trial in two response-inhibition paradigms. In summary, any behavioural effects that can be observed at the level of abstract task requirements reflect the influence of executive-control processes, both in task-switching paradigms and in response-inhibition paradigms.

Using an allergist task, Uengoer, Lotz and Pearce (2013) found that in a design A+/AX+/BY+/CY-, the blocked cue X was indicated to cause the outcome to a greater extent than the uncorrelated cue Y. This finding has been termed “the redundancy effect” by Pearce and Jones (2015). According to Vogel and Wagner (2017), the redundancy effect “presents a serious challenge for those theories of conditioning that compute learning through a global error-term” (p. 119). One such theory is the Rescorla-Wagner (1972) model, which predicts the opposite result, that Y will have a stronger association with the outcome than X. This thesis explored the basis of the redundancy effect in human causal learning. Evidence from Chapter 2 suggested that the redundancy effect was unlikely to have been due to differences in attention between X and Y. Chapter 3 explored whether differences in participants’ certainty about the causal status of X and of Y contributed to the redundancy effect. Manipulations aimed at disambiguating the effects that X had on the outcome, including outcome-additivity training and low outcome rate, resulted in lower ratings for this cue and a smaller redundancy effect. However, the redundancy effect was still significant with both manipulations, suggesting that while participants’ uncertainty about the causal status of X contributed to it, there may have been other factors. Chapter 4 investigated whether another factor was a lack of inhibition for cue C. In a scenario where inhibition was more plausible than in an allergist task, a negative correlation between causal ratings for C and for Y, and a positive correlation between ratings for C and the magnitude of the redundancy effect, were found. In addition, establishing C as inhibitory resulted in a smaller redundancy effect than establishing C as neutral. Overall, findings of this thesis suggest that the redundancy effect in human causal learning is the result of participants’ uncertainty about the causal status of X, and a lack of inhibition for C. Further work is recommended to explore whether combining manipulations targeting X and Y would reverse the redundancy effect, whether effects of outcome additivity and outcome rate on X are the result of participants’ uncertainty about this cue, and the extent to which participants rely on single versus summed error.

abstract: Watanabe, Náñez, and Sasaki (2001) introduced a phenomenon they named “task-irrelevant perceptual learning” in which near-threshold stimuli that are not essential to a given task can be associatively learned when consistently and concurrently paired with the focal task. The present study employs a visual paired-shapes recognition task, using colored polygon targets as salient attended focal stimuli, with the goal of comparing the increases in perceptual sensitivity observed when near-threshold stimuli are temporally paired in varying manners with focal targets. Experiment 1 separated and compared the target-acquisition and target-recognition phases and revealed that sensitivity improved most when the near-threshold motion stimuli were paired with the focal target-acquisition phase. The parameters of sensitivity improvement were motion detection, critical flicker fusion threshold (CFFT), and letter-orientation decoding. Experiment 2 tested perceptual learning of near-threshold stimuli when they were offset from the focal stimuli presentation by ±350 ms. Performance improvements in motion detection, CFFT, and decoding were significantly greater for the group in which near-threshold motion was presented after the focal target. Experiment 3 showed that participants with reading difficulties who were exposed to focal target-acquisition training improved in sensitivity in all visual measures. Experiment 4 tested whether near-threshold stimulus learning occurred cross-modally with auditory stimuli and served as an active control for the first, second, and third experiments. Here, a tone was paired with all focal stimuli, but the tone was 1 Hz higher or lower when paired with the targeted focal stimuli associated with recognition. In Experiment 4, there was no improvement in visual sensitivity, but there was significant improvement in tone discrimination. Thus, this study, as a whole, confirms that pairing near-threshold stimuli with focal stimuli can improve performance in just tone discrimination, or in motion detection, CFFT, and letter decoding. Findings further support the thesis that the act of trying to remember a focal target also elicited greater associative learning of correlated near-threshold stimulus than the act of recognizing a target. Finally, these findings support that we have developed a visual learning paradigm that may potentially mitigate some of the visual deficits that are often experienced by the reading disabled. / Dissertation/Thesis / Doctoral Dissertation Psychology 2016