Contextualization is often added to mathematical achievement items to place targeted mathematical operations in a real world context or in combinations with other mathematical skills. Such items may have unintended sources of difficulty, such as greater cognitive complexity than specified in the test blueprint. These types of items are being introduced to achievement exams through assessment programs such as SBAC and PARCC. Cognitive models have been created to assess sources of cognitive complexity in mathematics items, including a global model (Embretson&Daniel, 2008) and an adapted model (Lutz, Embretson,&Poggio, 2010). The current study proposes a new cognitive model structured around sources of working memory burden with an emphasis on contextualization. Full-information item response (IRT) models were applied to a state accountability test of mathematics achievement in middle school to examine impact on psychometric properties related to burden on working memory.

This study compared the relative importance of attentional capacity and processing speed accounts of cognitive aging with regard to how well they predict age differences in episodic and working memory performance. Two research projects were completed involving 150 and 100 right-handed adults between the ages of 18 and 90. In Study 1, each participant was administered measures of attentional capacity, processing speed and episodic memory. In Study 2 the processing speed measures were chosen to reduce the involvement of perceptual scanning and memory ability, and multiple measures of dual-task performance were used. Two working memory tasks were also administered along with the same episodic memory measures used in Study 1. The results of the studies revealed the following: (1) Measures of attentional capacity shared relatively smaller proportions of age-related episodic memory variance (14-45%) than measures of processing speed (60-87%). (2) Measures of attentional capacity shared very small proportions of age-related episodic memory variance (1-2%) independent of speed of processing. In contrast, measures of processing speed shared substantial proportions of age-related episodic memory variance (37-76%) that were independent of attentional capacity performance. (3) Measures of attentional capacity and processing speed shared comparable proportions of age-related working memory variance (58 and 65%) as well as comparable proportions of shared variance that was independent of the other mediator (10% attentional capacity; 17% processing speed). (4) The age-attentional capacity relations were attenuated to a large extent when performance on processing speed measures was controlled for (77-88%). In contrast the age-processing speed attenuations after control of attentional capacity performance were much smaller (6-55%). Taken together, these results provide little support for any predictive utility of the attentional capacity construct independent of processing speed ability in accounting for age-episodic memory relations although they are consistent with the notion that attentional capacity might mediate aspects of age-related working memory change. In contrast, these results contribute to the large body of evidence consistent with the notion that age-related decrements in the speed of executing relatively simple processing operations might be responsible for age-related differences in several cognitive domains.

Mentaliseringsförmåga innebär förmågan att ta en annan persons perspektiv, att förstå hur någon annan tänker och känner. Det innebär även att förstå de egna tankarna och reaktionerna relaterat till andra personers tankar och känslor. Det är viktigt med en välfungerande mentaliseringsförmåga för att kunna samverka med andra individer och sin omgivning på ett pragmatiskt och ändamålsenligt sätt. Det finns flera olika förmågor som kan vara viktiga för mentaliseringsförmågan, i vilken grad de påverkar är dock fortfarande oklart. Syftet med detta arbete var att undersöka mentaliseringsförmågan och dess samvariation med andra kognitiva förmågor hos barn i åldrarna 6-7 år. I föreliggande studie användes tio test för att undersöka vilka kognitiva förmågor som samverkade med mentaliseringsförmågan. De förmågor som testades var visuellt och auditivt arbetsminne, korttidsminne, språkförståelse och ickeverbal intelligens. Testgruppen bestod av 25 typiskt utvecklade barn i åldrarna 6:0–8:0 år med svenska som modersmål. Resultatet av testerna visade att ickeverbal intelligens, korttidsminne och språkförståelse korrelerade med barnens mentaliseringsförmåga. Vad gällde arbetsminnet verkade det främst som att en arbetsminneskapacitet upp till en viss nivå gynnade mentaliseringsförmågan, kapacitet över denna nivå verkade inte ha någon betydelse för prestationen. Det upptäcktes ingen enskild faktor som var viktigare än de andra för mentaliseringsförmågan, utan att samverkan av dessa förmågor är viktig. / Theory of mind, or mentalization ability, is the ability to understand how another individual thinks, acts and feels. It is important to develop a mentalization ability in order to interact with other people and the surrounding social environment in a pragmatic way. There are several abilities that might play an important role in the developmental process of Theory of mind. It is still uncertain to which degree these abilities effect the mentalization ability. The purpose with this study was to investigate the mentalization ability and its relationship with other cognitive abilities in children aged 6-7 years. In this study, ten different tests were used to analyze which abilities correlated with Theory of mind. The abilities that were tested were visual- and auditory working memory, short-term memory, non-verbal intelligence and language understanding. The participating test group consisted of 25 typically developed children aged 6:0-8:0 with Swedish as mother tongue. The results from the tests showed that the mentalization ability correlated with nonverbal intelligence, short-term memory and language understanding. It appears that a certain level of working memory is important, but that an exceptionally good working memory will not improve the mentalization ability further. The result showed that no single ability were more important than the others for the mentalization ability.

It is a testament to the complexity of learning that one hundred years of research on feedback has not produced universal prescriptions for training. Results are split in two directions; those recommending more feedback during training and those recommending less. Numerous theories that explain and predict certain feedback effects, but none explain the mixed findings in the literature. This has resulted in: a) no singular theory and b) little understanding of other factors that might affect the mechanism of feedback. The following series of studies systematically manipulated the cognitive load of the experimental task and measured learner working memory capacity. The overall question was whether forcing the learner to self-evaluate would result in more or less learning of a rule-based cognitive task and how this effect might be moderated by the working memory capacity of the learner and the load of the task to be learned. It was expected that high working memory capacity learners might learn more when difficulties were introduced for a simple task (via less supportive feedback). Instead, all groups not only learned more when receiving more support, the high working memory capacity learners appeared more able to utilize the additional feedback. Instead of providing their own support when feedback was minimal or lacking, high working memory capacity participants seemed best able to make use of the information provided in supportive feedback. Low working memory capacity participants seemed unable to either provide their own support when feedback was minimal or lacking, but also were not as able to make use of the information provided in more supportive feedback. The contribution of the current series of studies is an explanation of why and how appropriate level of feedback support can change based on the working memory capacity of the learner and demands of the task. Feedback can either impose a load upon the learner to self-evaluate or provide support for acquisition performance. Though learners may benefit from feedback neither too high nor too low, the current results indicate that additional feedback is most useful to those with the attentional resources available to utilize it.

Research has suggested that representational and perceptual systems draw upon some of the same processing structures, and evidence also has accumulated to suggest that representational formats are malleable by instructions. Very little research, however, has considered how nonspeech sounds are internally represented, and the use of audio in systems will often proceed under the assumption that separation of information by modality is sufficient for eliminating information processing conflicts. Three studies examined the representation of nonspeech sounds in working memory. In Experiment 1, a mental scanning paradigm suggested that nonspeech sounds can be flexibly represented in working memory, but also that a universal per-item scanning cost persisted across encoding strategies. Experiment 2 modified the sentence-picture verification task to include nonspeech sounds (i.e., a sound-sentence-picture verification task) and found evidence generally supporting three distinct formats of representation as well as a lingering effect of auditory stimuli for verification times across representational formats. Experiment 3 manipulated three formats of internal representation (verbal, visuospatial imagery, and auditory imagery) for a point estimation sonification task in the presence of three types of interference tasks (verbal, visuospatial, and auditory) in an effort to induce selective processing code (i.e., domain-specific working memory) interference. Results showed no selective interference but instead suggested a general performance decline (i.e., a general representational resource) for the sonification task in the presence of an interference task, regardless of the sonification encoding strategy or the qualitative interference task demands. Results suggested a distinct role of internal representations for nonspeech sounds with respect to cognitive theory. The predictions of the processing codes dimension of the multiple resources construct were not confirmed; possible explanations are explored. The practical implications for the use of nonspeech sounds in applications include a possible response time advantage when an external stimulus and the format of internal representation match.

The current study investigated the effects of aging on the strategic control of attention at encoding and the extent to which this relationship was mediated by working memory capacity. The value-directed remembering task used by Castel et al. (2009) was modified to include an inhibitory task demand (i.e., value-directed forgetting), and age differences were predicted due to declines in the efficiency of inhibitory mechanisms. Results confirmed this prediction, as older adults were less efficient in maximizing their selectivity scores upon the inclusion of task interference, and working memory was found to be supportive of performance. Results additionally support an age-related decline in the directed forgetting effect, such that older adults recalled and recognized fewer TBR items and more TBF items, relative to younger adults. Taken together, results suggest an age-related decline in the ability to inhibit goal-irrelevant information, thereby limiting working memory resources available for greater processing of goal-relevant information.

One of the most important parts of engineered and biological systems is the ability to acquire and interpret information from the surrounding world accurately and in time-scales relevant to the tasks critical to system performance. This classical concept of efficient signal acquisition has been a cornerstone of signal processing research, spawning traditional sampling theorems (e.g. Shannon-Nyquist sampling), efficient filter designs (e.g. the Parks-McClellan algorithm), novel VLSI chipsets for embedded systems, and optimal tracking algorithms (e.g. Kalman filtering). Traditional techniques have made minimal assumptions on the actual signals that were being measured and interpreted, essentially only assuming a limited bandwidth. While these assumptions have provided the foundational works in signal processing, recently the ability to collect and analyze large datasets have allowed researchers to see that many important signal classes have much more regularity than having finite bandwidth. One of the major advances of modern signal processing is to greatly improve on classical signal processing results by leveraging more specific signal statistics. By assuming even very broad classes of signals, signal acquisition and recovery can be greatly improved in regimes where classical techniques are extremely pessimistic. One of the most successful signal assumptions that has gained popularity in recet hears is notion of sparsity. Under the sparsity assumption, the signal is assumed to be composed of a small number of atomic signals from a potentially large dictionary. This limit in the underlying degrees of freedom (the number of atoms used) as opposed to the ambient dimension of the signal has allowed for improved signal acquisition, in particular when the number of measurements is severely limited. While techniques for leveraging sparsity have been explored extensively in many contexts, typically works in this regime concentrate on exploring static measurement systems which result in static measurements of static signals. Many systems, however, have non-trivial dynamic components, either in the measurement system's operation or in the nature of the signal being observed. Due to the promising prior work leveraging sparsity for signal acquisition and the large number of dynamical systems and signals in many important applications, it is critical to understand whether sparsity assumptions are compatible with dynamical systems. Therefore, this work seeks to understand how dynamics and sparsity can be used jointly in various aspects of signal measurement and inference. Specifically, this work looks at three different ways that dynamical systems and sparsity assumptions can interact. In terms of measurement systems, we analyze a dynamical neural network that accumulates signal information over time. We prove a series of bounds on the length of the input signal that drives the network that can be recovered from the values at the network nodes~[1--9]. We also analyze sparse signals that are generated via a dynamical system (i.e. a series of correlated, temporally ordered, sparse signals). For this class of signals, we present a series of inference algorithms that leverage both dynamics and sparsity information, improving the potential for signal recovery in a host of applications~[10--19]. As an extension of dynamical filtering, we show how these dynamic filtering ideas can be expanded to the broader class of spatially correlated signals. Specifically, explore how sparsity and spatial correlations can improve inference of material distributions and spectral super-resolution in hyperspectral imagery~[20--25]. Finally, we analyze dynamical systems that perform optimization routines for sparsity-based inference. We analyze a networked system driven by a continuous-time differential equation and show that such a system is capable of recovering a large variety of different sparse signal classes~[26--30].

Cognitive Event-Related Potential (ERP) recordings have been used to study the neurophysiological correlates of recognition memory. Previous ERP research has demonstrated that on tasks of recognition memory, Old items elicit ERP responses that are more positive in electrical amplitude than the ERP responses elicited by New items, commonly referred to as ERP Old/New positivity effects. ERP Old/New positivity effects have been used to make inferences about cognitive processes mediating recognition memory, such as the early frontal Old/New positivity effect that has been associated with familiarity and the late parietal Old/New positivity effect that has been associated with recollection. These effects have been demonstrated different types of stimuli and on different types of recognition memory tasks. However, a systematic comparison of ERP Old/New positivity effects across different recognition memory tasks is lacking, particularly with respect to Remote Long-term memory. This thesis asked how ERP Old/New positivity effects differ between tasks of Short-term, Recent Long-term, and Remote Long-term memory tasks for faces. Experiment 1 simulated the condition of limited overt communication skills by analyzing the brain responses to memory stimuli, regardless of the overt behavioural response from healthy, “honest” participants. Experiment 2 examined the ERP responses of healthy participants instructed to feign a memory impairment. ERP Old/New positivity effects similar to those described in the experimental ERP literature were observed on the Short-term and Remote Long-term memory tasks in both Experiments 1 and 2. However, response accuracy was lower than expected on the Recent Long-term task resulting in weak ERP results. A comparison of the ERP Old/New responses between the Honest Response (Experiment 1) and the Simulated Memory Malingering (Experiment 2) groups found that despite differing overt behavioural responses, the ERP Old/New responses remained similar. The results demonstrate a similar electrophysiological mechanism mediating Short-term, Recent Long-term, and Remote Long-term recognition memory ERP responses, despite the different neuroanatomical substrates that have been proposed these different types of memory. Although an improved measure of Recent Long-term memory is needed, the results of this thesis are promising and demonstrate that ERP recordings could provide an objective instrument for measuring recognition memory functioning in clinical settings.

The study examines language, memory and reading skills in children from two private schools in Victoria, British Columbia. Phonological processing and word-level decoding were significantly correlated, suggesting that familiarity with letters and their associated sounds are important for word-level reading. Phonological processing and decoding skill performance were significantly correlated with STM span and not WM span, suggesting that word-level decoding is not attentionally demanding for this sample of children. Decoding speed was inversely related to STM span; faster reading times and larger STM spans were highly predictive of one another. The children’s WM and STM task performance were relatively similar and may be reflective of efficient strategy use, such as word recognition, which reduces attention for processing in WM.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references (leaves 83-98). Issued in print and online. Available via ProQuest Digital Dissertations.