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(1 - 11 of 11)
- Title
- The structure of attentional biases in anxiety : a latent variable analysis of anxiety-related modulations of attentional control
- Creator
- Moran, Timothy Patrick
- Date
- 2015
- Collection
- Electronic Theses & Dissertations
- Description
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"[Examines] the interrelationships between anxiety, distraction by threat, distraction by physical salience and more general cognitive abilities, such as working memory capacity and perceptual/motor speed in 200 undergraduates."--from abstract.
- Title
- Hierarchical neural structures for spatial and feature-based attention in frontoparietal network
- Creator
- Hou, Youyang
- Date
- 2012
- Collection
- Electronic Theses & Dissertations
- Description
-
Selective attention facilitates our ability in detecting important information by optimizing limited attentional capacity. Previous studies have shown that a common frontoparietal network is involved in the top-down control of both spatial and feature-based attention, yet its functions in different attention tasks are not clear. In the current study, we used fMRI and multivariate pattern analysis (similarity and cluster analysis) to examine the relationship between attentional control of...
Show moreSelective attention facilitates our ability in detecting important information by optimizing limited attentional capacity. Previous studies have shown that a common frontoparietal network is involved in the top-down control of both spatial and feature-based attention, yet its functions in different attention tasks are not clear. In the current study, we used fMRI and multivariate pattern analysis (similarity and cluster analysis) to examine the relationship between attentional control of spatial and feature-based attention. Participants viewed a compound stimulus that contained multiple dot fields in two colors (red and green), two directions (upward and downward), and two spatial locations (left and right). An auditory cue instructed participants to attend to a particular feature or location on a given trial and to perform a change detection task on the cued dot fields. Different attention tasks activated a similar top-down attentional network in frontoparietal regions including intraparietal sulcus (IPS), frontal eye field (FEF) and ventral precentral sulcus (vPCS). There were only a few ROIs showed magnitude difference between different attention types. More importantly, cluster analysis showed clear hierarchical cluster structure in frontoparietal cortex for different attention tasks. In particular, activities belonged to same attention type shared similar multivoxel response patterns. This suggests that frontoparietal network controls different types of attentional selection with distinct, hierarchically organized neural substrates.
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- Title
- DECODING NEURAL MECHANISMS OF SURROUND SUPPRESSION IN FEATURE-BASED ATTENTION
- Creator
- Fang, Wanghaoming
- Date
- 2021
- Collection
- Electronic Theses & Dissertations
- Description
-
Feature-based attention (FBA) selectively enhances processing of an attended feature at the expense of unattended or task-irrelevant features. Recent studies showed that FBA modulates the perceptual space with both a monotonic profile (i.e., feature-similarity gain) and a non-monotonic profile (i.e., surround suppression). A significant question arises regarding the neural mechanism of the non-monotonic surround suppression effect. Previous studies have suggested that two candidate neuronal...
Show moreFeature-based attention (FBA) selectively enhances processing of an attended feature at the expense of unattended or task-irrelevant features. Recent studies showed that FBA modulates the perceptual space with both a monotonic profile (i.e., feature-similarity gain) and a non-monotonic profile (i.e., surround suppression). A significant question arises regarding the neural mechanism of the non-monotonic surround suppression effect. Previous studies have suggested that two candidate neuronal mechanisms could underlie these attentional modulations: a shift of neuronal tuning preference toward the attended feature, or a multiplicative gain modulation that scales the overall responses without changing their tuning property. Yet the empirical evidence for these mechanisms is still lacking. In the current work, we explored how these neuronal mechanism manifest at the level of fMRI BOLD measurement using a simulation approach. Specifically, we employed an encoding/decoding approach by first simulating voxel responses from neuronal population assuming either mechanism and then applying a regression-based inverted encoding model (IEM) and a Bayesian method to decode population representations. We found that both methods captured the signature patterns associated with these different neuronal mechanisms. In our second aim, we systematically varied the correlation structure of voxel noise to further compare these different multivariate methods in a stimulus classification task. Our results showed a clear advantage of the Bayesian method over IEM, suggesting that the Bayesian method was superior for deciphering neural representation given the prevalent noise correlation and variable tuning width in the brain. In sum, our current simulation work may provide a proof of concept for future empirical studies investigating cortical mechanism of FBA using non-invasive methods, as well as guidance for choosing suitable methods in these investigations.
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- Title
- Attention and stuttering : differentiating word-form encoding and working memory differences in adults who stutter
- Creator
- Tichenor, Seth E.
- Date
- 2020
- Collection
- Electronic Theses & Dissertations
- Description
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Though motoric, linguistic, and emotional/temperamental factors are commonly thought to contribute to the persistence or development of the stuttering condition in children, how these factors interact to influence the occurrence of moments of stuttering are unclear. Accounting for attentional allocation allows for the differentiation of word-form encoding and working memory processes in adults who stutter. 40 adults who stutter and 42 adults who do not stutter completed three complex working...
Show moreThough motoric, linguistic, and emotional/temperamental factors are commonly thought to contribute to the persistence or development of the stuttering condition in children, how these factors interact to influence the occurrence of moments of stuttering are unclear. Accounting for attentional allocation allows for the differentiation of word-form encoding and working memory processes in adults who stutter. 40 adults who stutter and 42 adults who do not stutter completed three complex working memory span tasks (a working memory capacity measure). These tasks systematically varied in their word-form activation requirements according to psycholinguistic theory. Results indicate that adults who stutter demonstrate working memory capacity differences as a function of word-form encoding influences. These results and the dual-task nature of the tasks allow for the further specification of theories into the origins of moments of stuttering.
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- Title
- The Timing of Misinformation Matters : Sleep both increases memory distortion and protects against it
- Creator
- Day, Alison J.
- Date
- 2020
- Collection
- Electronic Theses & Dissertations
- Description
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Prior work investigating the effect of sleep on false memory using the Deese-Roediger-McDermott paradigm has yielded equivocal results. Here, we sought to clarify the effect of sleep on false memory using the misinformation paradigm. Participants watched a film of a mock robbery, were given post-event misinformation about the film, and completed a recognition test after a 12-hour retention interval that consisted of waking activity or sleep. We manipulated when participants received...
Show morePrior work investigating the effect of sleep on false memory using the Deese-Roediger-McDermott paradigm has yielded equivocal results. Here, we sought to clarify the effect of sleep on false memory using the misinformation paradigm. Participants watched a film of a mock robbery, were given post-event misinformation about the film, and completed a recognition test after a 12-hour retention interval that consisted of waking activity or sleep. We manipulated when participants received misinformation; half received misinformation after watching the film and before the retention interval and half received misinformation after the retention interval, before the test. Thus, for participants who slept, half received misinformation prior to sleep and half received it after a sleep period. Most interesting, we found an interaction between sleep condition and timing of misinformation. In the sleep group, participants who received misinformation before the retention interval showed higher false memory than those who received misinformation after the retention interval. Timing of misinformation did not affect false memory in the wake condition. These results suggest that consolidation processes can have opposite effects on false memory. If conflicting information is presented after sleep, consolidation protects memory from distortion possibly by mitigating interference effects. However, the same consolidation processes may increase distortion if conflicting information is presented prior to sleep possibly by integrating related memories that are available at the time of sleep (i.e. the true event and the conflicting information). This work has implications for theories of memory and applied implications for the criminal justice system.
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- Title
- Sensory attenuation of action effects due to predictive forward models : when does it transfer to observed actions
- Creator
- Dewey, John A.
- Date
- 2012
- Collection
- Electronic Theses & Dissertations
- Description
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The sensory consequences of intentional actions (action effects) are often judged to be less intense compared to identical but externally generated stimuli. This phenomenon is normally explained in terms of predictive forward models within the sensorimotor system which partially inhibit predictable sensory feedback. An unsettled question is whether merely observing another agent performing a predictable action may also trigger a forward model with attendant sensory attenuation, or...
Show moreThe sensory consequences of intentional actions (action effects) are often judged to be less intense compared to identical but externally generated stimuli. This phenomenon is normally explained in terms of predictive forward models within the sensorimotor system which partially inhibit predictable sensory feedback. An unsettled question is whether merely observing another agent performing a predictable action may also trigger a forward model with attendant sensory attenuation, or alternatively, if a self-generated motor signal is necessary. I conducted three experiments to investigate this question using a visual speed discrimination task. Participants judged which of two moving stimuli was faster. The first stimulus was initiated by the participant's own key press (Self), another person's key press (Other), or the computer program (Computer), and had a fixed speed. The second stimulus was always initiated by the computer and had a variable speed. The point of subjective equality (PSE) was compared for each condition. In Experiment 1 participants performed the task at their own pace. The Self condition was judged to be slower than the Other or Computer conditions, while the latter two did not differ. To control for the possibility that self-initiated movements were more temporally predictable and/or less attended than movements by other agents, in Experiment 2 the pace was controlled by go signals, and a green light followed every human or computer action to indicate that a movement was about to begin. Compared to Experiment 1, the PSE increased in all conditions, but the Self condition was still judged to be slowest and the Computer condition the fastest, while the Other condition was in between. In Experiment 3 the predictability of the action effects was manipulated independently from the agent who produced them, in order to investigate whether expectation similarly attenuates the intensity of Self and Computer-initiated action effects. Participants used two keys to initiate moves in two directions (left or right). In the Predictable group, the direction of the move matched the direction of the key press 80% of the time. In the Unpredictable group, the directions only matched 50% of the time. Self moves were only attenuated in the Predictable group. I conclude that sensory attenuation is influenced by a combination of private and shared or publicly available information, and that the influence of public information may be particularly tuned to biological agents. Furthermore action effects must be predictable to become attenuated.
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- Title
- Worry and working memory : a behavioral & ERP investigation across the menstrual cycle
- Creator
- Gloe, Lilianne Marie
- Date
- 2019
- Collection
- Electronic Theses & Dissertations
- Description
-
"The current project examined the relationship between worry, a component of anxiety characterized by negative, future-oriented thought activity, and working memory in women. Further elucidation of this relationship occurred through use of multiple working memory measures; examining the P300, an event-related potential measured using electroencephalogram (EEG) thought to index resources available for cognitive processing; and considering the role of ovarian hormones. It was hypothesized that...
Show more"The current project examined the relationship between worry, a component of anxiety characterized by negative, future-oriented thought activity, and working memory in women. Further elucidation of this relationship occurred through use of multiple working memory measures; examining the P300, an event-related potential measured using electroencephalogram (EEG) thought to index resources available for cognitive processing; and considering the role of ovarian hormones. It was hypothesized that worry would be associated with poorer working memory function and reduced amplitude of the P300 at higher levels of task difficulty and estradiol. Participants were 65 naturally-cycling women who attended four visits across their menstrual cycles. On each visit day, data collection included a measure of daily worry (Penn State Worry Questionnaire), a saliva sample used to assay for estradiol, and completion of three working memory tasks (N-back task with EEG recording, Operation Span task and Reading Span task). Five multilevel models were constructed to examine the impact of within-subject fluctuation of Penn State Worry Questionnaire scores and estradiol values on N-back task accuracy, N-back task reaction time, N-back task P300 amplitude, Operation Span score, and Reading Span score. Task parameters of the N-back task (i.e. load and trial type) were included in the three models of the N-back task as indicators of task difficulty. Results indicated that within-subject fluctuations were not significantly related to working memory performance or the P300 amplitude. Potential reasons for null findings are explored and future directions are considered."--Page ii.
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- Title
- The development of behavioral self-regulation across preschool and its association with academic achievement
- Creator
- Montroy, Janelle J.
- Date
- 2014
- Collection
- Electronic Theses & Dissertations
- Description
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A fundamental accomplishment of early childhood is the development of self-regulation. Specifically, the advances children make in self-regulation during preschool (ages 3-5 years) are of interest as it appears that this is when children typically progress to more advanced, cognitive behavioral forms of self-regulation (e.g., Diamond, 2002). Likewise, past research suggests wide variation in the level of self-regulation skills children manifest during preschool (e.g., McClelland et al., 2007)...
Show moreA fundamental accomplishment of early childhood is the development of self-regulation. Specifically, the advances children make in self-regulation during preschool (ages 3-5 years) are of interest as it appears that this is when children typically progress to more advanced, cognitive behavioral forms of self-regulation (e.g., Diamond, 2002). Likewise, past research suggests wide variation in the level of self-regulation skills children manifest during preschool (e.g., McClelland et al., 2007). However, despite mounting evidence that preschool is an important time period for the development of self-regulation, little longitudinal work has been done investigating the developmental dynamics of self-regulation across more than two time points during preschool, particularly work that has evaluated possible heterogeneity in the trajectories of self-regulation across children. In this dissertation, I examined the development of behavioral self-regulation across preschool via latent growth curve modeling. I also evaluated possible heterogeneity in the developmental trajectories of children's behavioral self-regulation via growth mixture modeling. I then investigated the relationship between children's behavioral self-regulation trajectories and academic achievement at the end of preschool. Behavioral self-regulation and academic achievement were assessed for 652 preschool aged children across four years of study. Depending on the year, children were tested in the fall and spring (2 time-points) or across four time-points with the Head-Toes-Knees-Shoulders behavioral self-regulation task (Ponitz et al., 2008). Children were also tested on three literacy measures assessing phonological awareness, letter knowledge and early decoding skills, and an early math measure. Results suggested that the development of behavioral self-regulation across preschool is best represented by an exponential growth curve, and that there is variation in trajectories across children. Specifically, a three class model best represented the data with majority of children making exponential gains that either 1) began with lower initial levels of behavioral self-regulation and gains that accelerated across the preschool time period, or 2) began with higher levels of initial behavioral self-regulation with rapid gains early that decelerated across preschool. A third group of children demonstrated a no growth trajectory with low levels of initial behavioral self-regulation and little to no gains across the preschool time period. Results from the latent growth curve analysis suggested that the rate of gain across the preschool time period was associated with higher levels of early literacy and mathematics achievement at the end of preschool. Likewise, findings from the growth mixture analysis suggested that children who began preschool with higher levels of behavioral self-regulation and grew rapidly early following a decelerating exponential trajectory had higher levels of spring early literacy and mathematics achievement compared to children who began with lower levels of behavioral self-regulation and gained at an accelerating rate across preschool. However, any gains made by children in behavioral self-regulation, whether accelerating or decelerating were associated with higher levels of spring early literacy and mathematics achievement compared to children who made little to no behavioral self-regulation gains. Overall these findings indicate the importance of evaluating self-regulation skills early and providing support to children, particular children who may be at risk to make few gains across preschool in self-regulation as self-regulation is an important aspect of the skills children need in order to be prepared for kindergarten.
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- Title
- Does looking mean liking? A comparison of decision processes across perceptual and preferential choice
- Creator
- Yu, Shuli
- Date
- 2015
- Collection
- Electronic Theses & Dissertations
- Description
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While both perceptual and preferential decision-making share the underlying iterative process of sampling and integrating information, it is difficult to make direct comparisons between these two types of decisions because they have been studied under separate disciplines, each with its own distinctive techniques. Research in perceptual decisions has highlighted how covert attention improves behavioral performance in a variety of sensory tasks, from contrast sensitivity and orientation...
Show moreWhile both perceptual and preferential decision-making share the underlying iterative process of sampling and integrating information, it is difficult to make direct comparisons between these two types of decisions because they have been studied under separate disciplines, each with its own distinctive techniques. Research in perceptual decisions has highlighted how covert attention improves behavioral performance in a variety of sensory tasks, from contrast sensitivity and orientation discrimination (Liu, Abrams, & Carrasco, 2009) to motion coherence (Liu, Fuller, & Carrasco, 2006), as it enhances the processing of early visual information. Yet it has also been established that overt, relative attention, as measured by gaze exposure, is highly correlated with preferential choice in value-based decision making (Bird, Lauwereyns, & Crawford, 2012; Krajbich, Armel, & Rangel, 2010; Krajbich & Rangel, 2011; Shimojo, Simion, Shimojo, & Scheier, 2003).How do our higher-level intentions of being objective in perceptual choice versus being subjective in preference choice differentially impact choice formation? In this dissertation, I investigate how downstream decision processes, from information acquisition and evaluation to the eventual choice outcome, may be modulated by different task goals. In doing so, I explicate the role of selective attention in information search strategy, as it appears to have biasing effect in preferential but not perceptual choice. To compare choice formation in perceptual and preferential tasks, I used an experience-based paradigm that involved monitoring participants’ eye movements as they chose between two rapidly updating options (fishing ponds). Specifically, participants were asked to look at the two ponds and choose the pond they would rather fish from (preference frame), or choose the pond which had more fish surfacing on average (perceptual frame). Results indicate that participants’ eye gaze shifts toward the more favored option just before choice. However, this gaze bias was reduced in the perceptual frame. Moreover, perceptual participants maintained good discrimination accuracy even when they acquired less information. In contrast, preference participants were more likely to pick the option viewed for a relatively longer time, especially when less information was obtained. Data from both tasks are well described by a diffusion model of evidence accumulation which compares and integrates stimulus information based on eye gaze location, indicating a qualitatively similar choice process even when the higher-order tasks goals were different. However, consistent with behavioral results, the modeling reveals that distinction between task goals lies in quantitative differences across cognitive parameters as perceptual choice was associated with a lower gaze bias and greater information valuation than preferential choice. As it is expected that higher-order intentions are reflected in downstream choice processes, I sought to test if this differential impact of task goals depended on the ability to actively control information uptake. This was done by conducting a second study that directly manipulated stimulus exposure by presenting samples of information in a single continuous stream. Results indicate that perceptual and preference participants were equally susceptible to the gaze bias when they passively viewed the options. Together, these results highlight the importance of agency and voluntary control of relative attention during the processes of information search and valuation across perceptual and preferential choice.
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- Title
- An individual differences approach to investigate task-switching and its relationship to media multitasking
- Creator
- Alzahabi, Reem
- Date
- 2015
- Collection
- Electronic Theses & Dissertations
- Description
-
While multitasking with media has increased dramatically in recent years (Rideout, Foehr, & Roberts, 2010), the association between media multitasking and cognitive performance is poorly understood. In addition, the literature on the relationship between media multitasking and task-switching, one measure of cognitive control, has produced mixed results (Alzahabi & Becker, 2013, Minear, et al., 2013; Ophir, Nass, & Wagner, 2009). The goal of this work was to examine the relationship between...
Show moreWhile multitasking with media has increased dramatically in recent years (Rideout, Foehr, & Roberts, 2010), the association between media multitasking and cognitive performance is poorly understood. In addition, the literature on the relationship between media multitasking and task-switching, one measure of cognitive control, has produced mixed results (Alzahabi & Becker, 2013, Minear, et al., 2013; Ophir, Nass, & Wagner, 2009). The goal of this work was to examine the relationship between media multitasking and task-switching performance. However, in order to do so, we began by first examining the structure of task-switching and identifying the factors that contribute to switch costs. We used an individual differences approach to evaluate how the different putative mechanisms (advanced preparation, passive decay, attentional filtering, and response conflict resolution) are related to task-switching performance. Participants performed a series of three different task-switching paradigms, each designed to isolate the effects of a specific putative mechanism (e.g., advanced preparation). For each paradigm, participants completed three blocks of trials, each with a different classification task and different stimuli (animal/furniture, number/letter, and plant/transportation classification tasks). The use of these three different types of classifications within the same paradigms allowed us to perform a latent variable analysis using structural equation modeling to examine the fit of a model that captures the inter-relationship between these putative factors within an individual. Participants also completed a series of surveys to measure media multitasking and (fluid and crystallized) intelligence. The results suggest that task-switching performance is related to two somewhat independent factors, namely an advanced preparation factor and passive decay factor. This two-factor model provided best fit for both reaction time and error data. We found no support for the putative attentional filtering and response conflict resolution factors being related to an individual's task-switching performance. In addition, multitasking with media was related to a faster ability to prepare for tasks, resulting in faster task-switching performance without a cost to accuracy. Fluid intelligence was associated with slower task-switching ability, but higher task-switching accuracy. This indicates that fluid intelligence may allow one to recognize the need to prepare for a task-switch, causing one to slow down and effectively prepare for a task-switch, which in turn, improves accuracy. Media multitasking and intelligence were both less related to passive decay factors. These findings are consistent with a two-component model of task-switching (Sohn & Anderson, 2001), as well as an automatic/executive framework of cognitive control (Shneider & Shiffrin, 1977).
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- Title
- Investigating tempo biases in the mental representation of rhythm using the method of serial reproduction
- Creator
- Fromboluti, Elisa Kim
- Date
- 2016
- Collection
- Electronic Theses & Dissertations
- Description
-
"This dissertation tested two related hypotheses about the mental representation of rhythms in the sub-second to second time range, namely, a preferred tempo hypothesis and an input noise hypothesis. The preferred tempo hypothesis proposed that the inherent period of an internal oscillatory timekeeper biases the perceptual representation of rhythms, such that perceived rhythm tempo is systematically distorted towards the period of the oscillator. The oscillator period was hypothesized to be...
Show more"This dissertation tested two related hypotheses about the mental representation of rhythms in the sub-second to second time range, namely, a preferred tempo hypothesis and an input noise hypothesis. The preferred tempo hypothesis proposed that the inherent period of an internal oscillatory timekeeper biases the perceptual representation of rhythms, such that perceived rhythm tempo is systematically distorted towards the period of the oscillator. The oscillator period was hypothesized to be about 500 to 600 ms, based on past results showing that the perception and reproduction of sequence tempi are systematically biased towards this tempo. The input noise hypothesis proposed that increased variability in the initial encoding of a rhythm leads to greater bias towards preferred tempo in the perceptual representation of the rhythm. To test these hypotheses, three experiments used a novel approach to the study of rhythms, which was a serial reproduction (SR) paradigm. In the SR paradigm, participants are exposed to a stimulus and then reproduce it from memory, with their reproduction serving as the stimulus for the next participant in the series. This process is iterated across a series of participants, forming a chain of reproductions in which each participant's reproduction influences the content being transmitted. Typically, the final reproduction in a chain incorporates the accumulation of systematic distortion across reproductions in the chain, thereby magnifying the bias introduced at each iteration. Bias in serial reproductions results from the adjustment of noisy input representations towards a value consistent with prior experience during perceptual representation. Greater noise in the stimulus input leads to greater bias, and thus faster chain drift. The experiments herein varied the seed tempo of rhythms initiating SR chains, asked a series of participants to reproduce the timing of iterated rhythms by tapping, and then compared the final reproduced tempo to the seed tempo of the chain. In line with the preferred tempo hypothesis, across experiments, when participants passively observed the stimulus rhythms before reproducing them, chains initiated at tempi ranging from 150 to 1709 ms converged to participants' preferred tempo. In line with the input noise hypothesis, when participants synchronized finger taps with stimulus rhythms during exposure, reproductions were less biased towards preferred tempo, leading chains to converge to preferred tempo more slowly or not at all. A similar pattern of results was obtained regardless of whether SR chains consisted of reproductions by different participants or by the same participant. Also consistent with the input noise hypothesis, when participants were exposed to and reproduced visual rhythms instead of auditory rhythms, reproductions tended to be more biased towards preferred tempo, leading chains to converge more quickly for visual than auditory rhythms. Synchronizing with visual rhythms slowed convergence of SR chains to preferred tempo, but to a lesser degree than for auditory rhythms. Overall, by testing these hypotheses in the domain of rhythm using the method of serial reproduction, the results of this dissertation advance basic research on tempo biases in rhythm perception and production. More broadly, the findings demonstrate the feasibility of using the serial reproduction paradigm in a novel domain and lay the groundwork for the future application of this approach to probe underlying biases in the mental representation of rhythm."--Pages ii-iii.
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