Working memory, or the ability to maintain and manipulate information in mind when it is no longer physically present, is a pervasive yet severely capacity-limited component of cognition. Visual working memory, also known as visual short-term memory (VSTM), is limited to three or four items on average, with individual differences that range from roughly two to up to six items. Despite agreement that capacity is functionally limited, the current literature is split with respect to the nature of VSTM representations on two key questions: (1) What information is maintained in VSTM? (2) How is information stored in VSTM? The studies presented here address these questions using an event-related potential (ERP) task and a series of behavioural experiments that incorporate attentional selection via retrospective cueing (retro-cues). Experiment 1 manipulated both the number of features and the number of locations to be remembered in a lateralized change-detection task, with differences in the amplitude and topography of the resulting contralateral delay activity (CDA) indicating separate stores for features and locations. Experiments 2a-c established the basic effects of retro-cues on change-detection tasks, showing that attentional selection operated on one system at a time, with overall shorter response times and increased capacity estimates once baseline capacity was exceeded. Experiments 3a-b demonstrated that retro-cues biased VSTM resources to the cued item at the expense of representational strength of the other, non-cued items, showing flexible reallocation of resources. Experiments 4a-b presented multiple retro-cues to further examine the flexible reallocation of resources in VSTM, showing that capacity benefits depended on spatial specificity of retro-cues and that VSTM weights could be reallocated multiple times before probe comparison. Experiment 5 discounted the potential role of a general alerting mechanism in boosting capacity estimates, showing again that the retro-cue benefit required specificity of the cue. Experiment 6 showed that flexible reallocation of resources within one system did not change the online maintenance of representations within the other system. Thus, the studies collectively address the questions of (1) what and (2) how information is stored by supporting a two-system model of VSTM in which (1) locations and features are stored (2) independently via flexibly allocated resources.

This study furthers our understanding of naturalistic strategy use by ABI survivors with executive dysfunction. Strategies used by 14 stroke survivors, 12 TBI survivors and 25 matched controls on the Baycrest Multiple Errands Test (BMET) were scored. Relationships between strategy use and BMET performance were found for all groups (rs=.30-.71). TBI participants experienced monitoring difficulties (rs=-.38 to -.71). Greater use of task setting strategies was associated with better performance for all participants. Results support the theory of fractionation of the prefrontal lobes and the suggestion for further fractionation of the task setting and monitoring processes. Strategy use was consistently correlated with scores on the AMPS (rs=.30-.75) indicating good ecological validity. Differences in patterns of strategy use between stroke and TBI participants suggest these types of ABIs do not affect real-world performance in the same way. This study indicates the importance of understanding naturalistic strategy use for cognitive rehabilitation after ABI.

Previous research on animate motion perception indicates that animacy detection may be an evolutionarily developed mechanism of the visual system, responsible for adaptive alerting to other organisms in the environment. The present study further examined previously described attention capture by animate motion, and explored whether capture may be modulated by type of animacy (e.g., human motion vs. other animacy). The link between subjective animacy experience and perceptual processing was also examined. Results suggested that attention capture by animacy extends to situations in which animate motion is self-relevant. Animate motion entering the observer’s visual field captured attention relative to motion leaving out of the visual field. Subjective ratings of animacy experience also reliably predict reaction time in perceptual/attention tasks. Implications for theories of social cognition and higher order processing of agency are discussed.

Theories of age-related memory decline debate whether the problem lies at the level of encoding or consciously accessing information at the level of retrieval. Deficits at encoding may be due to the inability to bind relations among objects. The present research implements eye movement monitoring into an associative memory task to explore age-related memory at encoding and retrieval. Eye movements of older and younger adults are compared. Three solitary items were presented during the study phase, and test responses were whether the spatial relation of these objects to one another was intact or manipulated when subsequently presented all together. Observed differences at the level of encoding in addition to the level of retrieval clarifies that there is not a deficit in consciously accessing encoded representations. Further, differences in relational binding at the level of encoding were observed, which supports the association deficit theory of memory and aging.

Recent evidence suggests that the task of managing a bilingual individual’s two languages is carried out by general attentional mechanisms. Researchers have found evidence for bilingual advantages in attention, specifically on tasks that involve inhibiting irrelevant information, which are believed to stem from lifelong practice at inhibiting the language system not currently in use. In the present study we hypothesized that, since bilinguals are better at inhibiting irrelevant information, they should show memory disadvantages if previously irrelevant information becomes relevant. 12 bilingual and 12 monolingual participants (age range:19-27) were tested in an eye tracking paradigm where the relational manipulation effect (the tendency to direct more viewing to manipulated regions of previously viewed scenes) was used to access memory for scenes that had been presented as distractors during a study block. No differences in memory were observed. However, we observed a significant difference in general viewing patterns between the two language groups, such that bilinguals made significantly shorter fixations.

Master of Science / Department of Psychology / Lester C. Loschky / How are episodes of picture stories remembered, and what role does the order of their components (exposition, complication, and resolution) play in that memory? We presented picture sequence episodes of the “Red Balloon” with the order of their components either normal or scrambled. As predicted by story grammar theories, scrambling episode components reduced self-rated comprehension and recall. However, scrambling also produced faster recognition memory responses for hits. This suggests that episode component scrambling interfered with the transformation of perceptual to conceptual information in LTM, producing an advantage for familiarity over recollection. Additionally, recall memory decreased monotonically from exposition to resolution, whereas recognition memory showed the opposite result, and this was the same whether components were normally ordered or scrambled. This suggests that memory for picture story episode components is based on their information content rather than their temporal order, and that information from picture stories moves from perceptual to conceptual memory representations.

Doctor of Philosophy / Department of Psychology / Gary Brase / Consumers’ choice behaviors are influenced by multifaceted decision factors. Information processing theory (Bettman, 1979) predicts that consumers’ decision processes are constructed at the time of a decision, and consumers’ meta-goals model (Bettman, Luce, & Payne, 1998) posits that their choice behaviors are generally guided by the minimization of cognitive effort and negative emotion, and the maximization of accuracy and justification. Insightful as this model may be at describing how consumers’ choices are shaped, it does not specify the interactions among the goals, assess the benefits of cognitive effort, or fairly evaluates the importance of emotion and justification in consumer decision making. Thus, the current studies collectively propose an alternative meta-goals choice model. Particularly, the current studies speculate on the importance of regret in consumer decision making. Consistent with previous research, Study 1 shows that participants trade-off between cognitive effort and accuracy goals depending on the monetary value of the products at hand, suggesting that the cognitive effort-accuracy trade-off may be moderated by price. Study 2 investigated the impact of cognitive effort on the experience of regret, showing the effectiveness of cognitive effort in attenuating the experienced regret. This relationship is explored with respect to the role of cognitive effort as a means of the justification factor in Study 3. Results showed that unjustified (wasted) cognitive effort did not make a substantial difference in post-purchase regret, but under spent cognitive effort generated more post-purchase regret. Study 4 examined both anticipated and experienced regret in relation to cognitive effort and justification; results showed that an exertion of cognitive effort is helpful in reducing the experience of regret but the justification of the choice also affects this relationship especially when the choice during the decision search is incongruent with the final decision. These results from current studies suggest interrelations between consumers’ four meta-goals. Based on these findings, an alternative meta-goals model is proposed which includes the benefits of cognitive effort exertion on consumer decision making, shedding light on how and when consumers choose to exert effort in an attempt to alleviate the potential future experience of regret.

Doctor of Philosophy / Department of Educational Leadership / Sarah Jane Fishback / This study investigated the relationship between the tolerance of ambiguity (AT) levels of the officers attending the U.S. Army’s School of Advanced Military Studies (SAMS) and the creativity of the military plans they developed. Located aboard Fort Leavenworth, KS, SAMS is an Army school providing education to specially selected officers in preparation for duties in positions as battalion commanders and lead planners for Army divisions and corps. The officers at SAMS are grouped into seminars for their classes, and they remain with their seminars throughout the yearlong educational program. The twin purposes of this study were to (a) test for the relationship between AT and creativity suggested by various theories of creativity and (b) contribute to the Army’s efforts to increase the creativity of its officers by empirically identifying the expected positive correlation between the officers AT levels and the creativity of their plans. A sample of 66 officers participated in the study. They each independently developed a military plan in response to a common notional scenario. Subsequently they each independently completed the short version of Norton’s (1975) MAT-50 to measure their levels of AT. Their plans were assessed for creativity using Amabile’s Consensual Assessment Technique (CAT). The high inter-rater reliability among the judges (r = .82) demonstrated the effectiveness of the CAT as a method for assessing the creativity of military plans. Counter to the expectation, analysis of the data revealed a small negative correlation throughout the sample between AT scores and the creativity of the plans, producing a disconfirmation dilemma for the researcher. Analysis revealed that the sample’s collective levels of AT differed among the various subscales of the MAT-50. Additionally, post hoc analysis revealed statistically significant variance of the creativity of the officers’ plans between the different seminars to which they were assigned. In the seminar with the highest creativity scores, there was a small positive correlation between AT and creativity, while in the seminar with the lowest creativity scores, there was a medium sized negative correlation between the two variables. Implications of these findings and recommendations for future research are discussed.

Doctor of Philosophy / Department of Psychological Sciences / Gary L. Brase / Risky decision making occurs in both humans and non-human animals. For a large portion of the history of scientific investigation into human judgment and decision making, risky behavior has been viewed as flawed and irrational. However, the past several decades have seen advances in the view of human rationality. Scientists have suggested that, rather than using probability theory as the metric by which humans are judged as rational or irrational, human minds should be evaluated with respect to specific ecologies (e.g., Gigerenzer & Selten, 2001) with some scientists going further and specifying the ecologies as those which our ancestors evolved; essentially, our minds and their decision processes are adapted to solve specific recurring problems, and to solve those problems in specific environments. Within the domain of risky decision making there are a number of theories and models which are consistent with the hypothesis that human (and non-human) minds are molded for specific behavioral patterns based on environmental cues. One example is the priority heuristic. The priority heuristic is based in the ecological rationality approach—that heuristics are designed for specific ecologies. However, the ecological rationality of the priority heuristic is underspecified. Studies One and Two of the present dissertation compared predictions made by two models of risk-taking from evolutionary biology and behavioral ecology (dominance theory and risk-sensitive foraging) with a variety of predictions made by the priority heuristic. Data clearly showed that risk-sensitive foraging outperforms the priority heuristic (Study One) and that the priority heuristic cannot account for the motivation to acquire a minimum number of resources. Study Two showed mixed results for the priority heuristic when compared to dominance theory. Specifically, choice patterns were consistent with the priority heuristic, but process data in the form of decision times were not consistent with the priority heuristic. Also, the data pointed to a strong effect for desiring higher status when competing against others of varying status. Study Three compared four potential models of risky decision making in an attempt to extend the pattern of results from Studies One and Two showing general risk-sensitivity when attempting to achieve a specified need level (Money for Study One; Status for Study Two). Also, Study Three attempted to clarify the scope of the pattern of general risk-sensitivity by examining differential patterns of results based on whether the models predicted motivations to achieve need levels for money, status, or both. Results from Study Three were consistent with a general model of risk-sensitivity which operated on both monetary need levels and status need levels. This effect was additionally ubiquitous for males and females, contrary to predictions by dominance theory. The data from three studies showed support for a general model of risk-sensitivity consistent with those proposed by others (Mishra, 2010). The concept and implications of this general risk-sensitivity model are discussed, as well as future directions to understand the finer details and potential scope of this particular general risk-sensitivity model.

In four experiments we used eye-tracking to investigate biases in looking behaviour during visual decision making tasks. In Experiment 1, participants viewed arrays of images of photographic art and decided which image was preferred (from a set of either two or eight alternatives). To analyze gaze behaviour during the decision we identified dwells (where a dwell is a series of consecutive fixations on a decision alternative). This analysis revealed two forms of gaze bias in the period prior to the response. Replicating prior findings (Shimojo, Simion, Shimojo, & Scheier, 2003), just prior to the response we found an increase in the frequency of dwells on the chosen item. In addition, throughout the decision, dwells on the chosen item were longer than dwells on other items. This pattern of biases was extremely similar across preference and non-preference decision instructions, but overall the biases were more pronounced in eight alternative decisions than in two alternative decisions. In Experiment 2 we manipulated the number of decision alternatives while controlling for differences in the stimulus displays. Participants viewed displays containing six everyday items, and chose either which of two sets of three items was the most expensive (two alternative set selection task) or which of the six items was the most expensive (six alternative item selection task). Consistent with Experiment 1, participants exhibited greater selectivity in their processing of stimulus information in the six alternative decisions compared to the two alternative decisions. In Experiments 3 and 4 we manipulated stimulus exposure in order to test predictions derived from the Gaze Cascade model (Shimojo et al., 2003). In Experiment 3, participants performed an eight alternative decision in which four of the items had been pre-exposed prior to the decision. In Experiment 4, stimulus exposure was manipulated during the ongoing decision using a gaze-contingent methodology. While these manipulations of stimulus exposure had strong effects on gaze bias, the specific predictions of the model were not supported. Rather, we suggest an interpretation based on prior research, according to which the gaze bias reflects the selective processing of stimulus information according to its relevance to the decision task.