Two priming experiments extending the work of Loftus (1973) and Loftus and Loftus (1974) were conducted to investigate retrieval from semantic memory. Subjects produced a letter-restricted instance from a semantic category on a prime trial, and then were asked to produce a second, different instance from the category on the target trial. The letter-restrictor for the target trial allowed a response that was either high- or low-related to the prime trial response. In addition, in Experiment 1 the dominance of the target response was varied, while in Experiment 2 the dominance of the prime response was varied. High prime-target response relatedness significantly improved target trial performance, but only in conjunction with high target dominance. Target performance was not affected by the dominance of the prime response. These results indicate that the priming of category exemplar retrieval is not simply a matter of category repetition; the interaction of exemplar dominance and its relatedness to a just-retrieved exemplar is an important determinant of retrieval performance. Two activation models are developed to account for the findings.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

Text in Afrikaans / 'n Ondersoek word gedoen na die aard, die oorsprong en die geloofwaardigheid van die inligtingsvetwerkingsbenadering in die kognitiewe sielkunde. Reeds vir die antieke Griekse denkers vorm logika 'n uitdrukking van die essensie van rede. Hierdie beskouing sou tydens die sewentiende eeu ontwikkel word tot die gedagte aan die subjek as 'n innerlike ruimte waarbinne die wereld van objekte in terme van logies-wiskundige rekonstruksies geken word. Die materialistiese beskouing reken dat alle dinge op hierdie wyse kenbaar is, maar ontken die subjek as vootwaarde vir sulke kennis, deur te poog om ook dit tot die objektiewe orde te reduseer. Die inligtingsteorie volg uit die ontstaan van die wiskundige logika, en hied 'n algemene teorie van probleemoplossing, die teorie van formele sisteme. Dit lewer 'n model vir die denke as die manipulering van simbole d.m.v. formele manipulasiereels. Hierdie simbole is abstrakte objekte, slegs onderskeibaar aan die hand van hulle vorm, maar kan onderling in hulle logiese samehang die wetmatige relasies tussen dinge soos dit in die wereld voorkom behou, en so dien as voorstellings van die wereld. Die funksionalistiese benadering tot denke is 'n poging om die probleem van die verhouding tussen denke en gedrag (die subjek-objekprobleem) op te los deur 'n toepassing van die inligtingsteorie. Funksionaliste wat die betekenisaspek of intensionele inhoud van die denke emstig opneem, reken dat terwyl voorstellings innerlik funksioneer as simbole in 'n formele sisteem, dit ook dien as verwysings na objekte in die ervaringswereld. Diegene wat 'n materialistiese reduksionisme aanvaarbaar vind ontken bloot die verwysingsvlak, en beskou die innerlike vetwerkings suiwer as sintaktiese prosesse. Aan die hand van 'n ontleding van die inligtingsvetwerkingsbenadering in verskillende manifestasies daarvan, word aangetoon dat die oplossing wat gebied word vir die probleem van die verhouding tussen denke en gedrag onsuksesvol is. Solank die onderliggende objektivistiese vooraannames gehandhaaf word, is die probleem waarskynlik in beginsel onoplosbaar. 'n Verskuiwing van perspektief is wenslik. Aandag moet gegee word aan die konkrete betrokkenheid van 'n mens in sy wereld, wat hy in handeling tot uitdrukking bring, en wat in taal binne 'n gemeenskaplike raamwerk geplaas word. / An inquiry is conducted into the nature, origins, and tenability of the information processing approach in cognitive psychology. Logic regarded as the essence of reason originates with classical Greek philosophy. In the seventeenth century this developed into the idea of the subject as an inner space where the world of objects is known by way of a mathematical-logical reconstruction. To materialists all things are known in this way, but the existence of the subject as a precondition for such knowledge is denied, by attempting to reduce it to the world of objects. Information theory developed in the wake of mathematical logic, and presents a general theory of problem-solving in the theory of formal systems. This suggests a model of the mind in terms of the manipulation of symbols by way of formal rules. Such symbols are abstract objects, individuated only by their form. Through the logical relationships among them they are able to maintain the lawlike relationships that exist among things in the world. In this way they serve as representations of the world. The functionalist approach to mind is an attempt to solve the problem of the relationship between thought and behaviour (i.e. the subject-object problem) by the application of information theory. Those functionalists that take the aspect of meaning or the intentional content of the mind seriously, argue that while representations function inwardly as symbols in a formal system, they also refer to objects in the world of experience. Materialist reductionists simply deny the level of referral, and view the inner computations as a purely syntactical process. By analyzing the information processing approach in various guises, it is shown that the solution given to the problem of the relationship between mind and behaviour does not succeed. As long as the underlying objectivist assumptions are maintained, this problem appears to be insoluble. A shift of perspective is suggested. Attention should be directed to the concrete involvement of a person with his world, as expressed in action, and how this is placed in a communal frame of reference through the power of language. / Psychology / D. Litt. et Phil. (Psychology)

周期性是語音信號一個重要的特徵。周期性對於聲調語言更是不可或缺。在聲調語言中，音調的輪廓形狀決定了發音的語義。語音的周期性增強旨在修復受噪聲影響的語音信號的波形周期性，從而增強音調和聲調的聽覺感知。 / 本論文提出了一種新的語音周期性增強方法。在該方法中，語音的周期性增強通過對線性預測殘差信號在變換域的周期/非周期分解來達到。線性預測殘差信號一般被認為是語音周期性的主要載體，該信號以基音同步的方式通過重疊頻率變換在變換域被分解。周期性增強通過對變換參數的加權來達到：代表周期性成分的變換參數被增強，而代表非周期成分的變換參數被削弱。本文提出和評估了三種設置變換參數權重的方法。這三種權重分別是固定權重、自適應權重和維納（Wiener）濾波器參數。 / 為了保証有效的周期/非周期分解，本研究提出了一種新的基音周期估計方法。該方法使用瞬時累積峰值譜作為語音的諧波特徵表示；噪聲對峰值譜影響的概率分布用高斯混合密度模型來表示。基音周期的估計問題則表示為l₁規則化的最大釋然估計。對於該非凸優化問題，本文提出了兩種凸優化方法來近似求解。本文提出的基音周期估計方法優于傳統方法，它在低信噪比的條件下能夠取得較高的估計准確率。 / 本文對提出的語音周期性增強方法進行了全面的實驗和評估。實驗結果表明，該方法能夠有效地修復受損語音的諧波結搆和波形周期性。對比其他測試的語音和語音周期性增強方法，本文的新方法能夠更顯著地提高語音的質量。其輸出語音音質的客觀測量參數，例如SNR和PESQ，優于其他方法。 / Periodicity is an important attribute of speech signals. It is an essential element of tonal languages, where the meaning of a word is determined by the pitch contour. Speech periodicity enhancement is the process of restoring waveform periodicity of noise-corrupted speech, in order to improve human perception of pitch and tone in noisy environments. / This thesis presents a novel approach to speech periodicity enhancement. The enhancement is achieved through periodic-aperiodic decomposition of the linear prediction residual signal in a transform domain. Transform coefficients that represent the periodic component are amplified to enhance the periodicity, and those coefficients representing the aperiodic components are attenuated to suppress the noise. We propose and evaluate dfferent methods of assigning coefficient weights for periodicity enhancement. These methods include simple fixed weights, adaptive weights, and transform-domain Wiener filtering. / As a key component for periodic-aperiodic decomposition, a novel method of robust pitch estimation is developed. The temporally accumulated peak spectrum is proposed as a robust representation of speech harmonics. Gaussian mixture model is employed to model the effect of noise on the peak spectrum. Pitch estimation is formulated as a problem of l₁-regularized maximum likelihood estimation, in which prior information is exploited. Two convex optimization approaches are developed to solve the associated non-convex optimization problem. The proposed pitch estimation method significantly outperforms the conventional methods. It attains high estimation accuracy for various types of noise at very low signal-to-noise ratio (e.g., -5 dB). / Experimental results confirm that with the proposed approach of periodicity enhancement, speech harmonic structure and waveform periodicity can be effectively restored. Compared with other speech and periodicity enhancement methods evaluated in this study, the proposed method can produce speech outputs with noticeably higher quality in terms of different objective measurements, such as SNR and PESQ. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Huang, Feng. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 130-143). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Speech enhancement --- p.1 / Chapter 1.2 --- Speech periodicity and enhancement --- p.4 / Chapter 1.3 --- Research motivations and objectives --- p.6 / Chapter 1.4 --- Thesis outline --- p.7 / Chapter I --- Transform-domain signal decomposition --- p.9 / Chapter 2 --- Speech representation model --- p.10 / Chapter 2.1 --- Overview of speech modeling --- p.10 / Chapter 2.2 --- Speech analysis --- p.12 / Chapter 2.2.1 --- Linear prediction analysis --- p.13 / Chapter 2.2.2 --- Constant-pitch warping --- p.15 / Chapter 2.2.3 --- Two-stage lapped frequency transforms --- p.18 / Chapter 2.2.4 --- Signal segmentation --- p.20 / Chapter 2.3 --- Speech synthesis --- p.22 / Chapter 2.4 --- Applications --- p.24 / Chapter 2.4.1 --- Speech coding --- p.24 / Chapter 2.4.2 --- Speech modification --- p.25 / Chapter 3 --- Signal decomposition for periodicity enhancement --- p.29 / Chapter 3.1 --- Periodic-aperiodic decomposition --- p.29 / Chapter 3.2 --- Periodicity enhancement of noisy speech --- p.33 / Chapter 3.2.1 --- Noise effect on transform coefficients --- p.33 / Chapter 3.2.2 --- Principle of periodicity enhancement --- p.34 / Chapter 3.2.3 --- Research focuses --- p.36 / Chapter 3.3 --- Related issues for noisy speech --- p.38 / Chapter 3.3.1 --- LP coefficient estimation --- p.38 / Chapter 3.3.2 --- Model adjustments --- p.40 / Chapter II --- Robust pitch estimation --- p.43 / Chapter 4 --- Pitch estimation with temporally accumulated peak spectrum --- p.44 / Chapter 4.1 --- Review of pitch estimation methods --- p.44 / Chapter 4.2 --- Peak spectrum and inter-frame spectrum similarity --- p.45 / Chapter 4.3 --- Temporally accumulated peak spectrum --- p.49 / Chapter 4.4 --- Pitch estimation using autocorrelation of TAPS --- p.53 / Chapter 4.5 --- Experimental evaluation --- p.55 / Chapter 4.5.1 --- Test data --- p.55 / Chapter 4.5.2 --- Performance metrics --- p.56 / Chapter 4.5.3 --- Accumulated frame number --- p.56 / Chapter 4.5.4 --- Experimental results --- p.57 / Chapter 5 --- Pitch estimation using sparse estimation techniques --- p.59 / Chapter 5.1 --- Sparse representation of TAPS --- p.59 / Chapter 5.2 --- Sparse weight estimation using l₁-regularized minimization --- p.60 / Chapter 5.2.1 --- Least absolute shrinkage and selection operator --- p.61 / Chapter 5.2.2 --- Gaussian mixture distribution for noise effect --- p.62 / Chapter 5.2.3 --- Convex approximation --- p.62 / Chapter 5.2.4 --- Difference-of-convex programming --- p.63 / Chapter 5.3 --- Pitch estimation from sparse weight vector --- p.65 / Chapter 5.4 --- Experimental evaluation --- p.65 / Chapter 5.4.1 --- Experiment settings --- p.65 / Chapter 5.4.2 --- Peak spectrum exemplar set --- p.67 / Chapter 5.4.3 --- Gaussian mixture density --- p.67 / Chapter 5.4.4 --- Experimental results --- p.68 / Chapter 5.5 --- Summary of robust pitch estimation --- p.76 / Chapter III --- Speech periodicity enhancement --- p.78 / Chapter 6 --- Transform-domain coefficient weighting --- p.79 / Chapter 6.1 --- Overview of the proposed framework --- p.79 / Chapter 6.2 --- Transform coefficient weighting --- p.81 / Chapter 6.3 --- Experimental evaluation --- p.82 / Chapter 6.3.1 --- Experiment settings --- p.83 / Chapter 6.3.2 --- Experimental results --- p.85 / Chapter 7 --- Adaptive coefficient weighting --- p.89 / Chapter 7.1 --- Motivation of adaptive weights --- p.89 / Chapter 7.2 --- Energy concentration of voiced and unvoiced speech --- p.91 / Chapter 7.2.1 --- Energy concentration measures --- p.91 / Chapter 7.2.2 --- Voiced/Unvoiced discrimination --- p.92 / Chapter 7.3 --- Pitch estimation confidence --- p.94 / Chapter 7.3.1 --- Basis of confidence measure --- p.94 / Chapter 7.3.2 --- Robustness of the confidence measure --- p.97 / Chapter 7.4 --- Adaptive coefficient weighting --- p.99 / Chapter 7.5 --- Experimental evaluation --- p.103 / Chapter 8 --- Transform-domain Wiener filtering --- p.107 / Chapter 8.1 --- Transform-domain Wiener filtering for periodicity enhancement --- p.108 / Chapter 8.1.1 --- The MMSE optimal Wiener filter --- p.108 / Chapter 8.1.2 --- Wiener filter for periodic component --- p.109 / Chapter 8.1.3 --- Wiener filter for aperiodic components --- p.109 / Chapter 8.2 --- Filter parameter estimation --- p.110 / Chapter 8.2.1 --- Filter parameters for aperiodic components --- p.110 / Chapter 8.2.2 --- Filter parameters for periodic component --- p.111 / Chapter 8.3 --- Experimental evaluation --- p.112 / Chapter 8.4 --- Summary of speech periodicity enhancement --- p.117 / Chapter 9 --- Conclusions and future directions --- p.119 / Chapter 9.1 --- Conclusions --- p.119 / Chapter 9.2 --- Contributions --- p.121 / Chapter 9.3 --- Future directions --- p.122 / Chapter A --- Algorithms for LP coefficient estimation --- p.123 / Chapter A.1 --- Kalman filtering of noisy speech --- p.123 / Chapter A.2 --- Codebook driven approach --- p.126 / Bibliography --- p.130

Methods of instruction which are intended to facilitate understanding tend to incorporate all of the elements required for understanding in the instructions. Frequently, these types of instructions may overwhelm a learner???s limited working memory and hinder learning. The five experiments reported in this thesis were generated by cognitive load theory. Cognitive load theory is based on the assumption that features of human cognitive architecture have important implications for how we learn and understand. The experiments examined an alternative approach to instructional design which had the goal of promoting schema construction in order to foster understanding. A two phase, isolated-interacting elements learning approach was developed which, in the first phase, artificially reduced the element interactivity of complex material by presenting the material as isolated elements of information that could be processed serially, rather than simultaneously, in working memory. In the second phase of instruction, all the information for understanding was presented. The control group???s instruction was a more conventional approach to promoting understanding where all the information for understanding was presented in both Phase 1 and 2. Although a possible consequence of artificially reducing the element interactivity of material may be an initial decrease in a student???s capacity for understanding, it was hypothesised that over the longer term it would lead to an increase in learners??? understanding. The results reported in this thesis provide powerful evidence that for certain groups of learners, information is better learnt through the isolated-interacting elements instructional method. Evidence is also provided in support of the proposal that schema construction is the mechanism underlying the success of the isolated-interacting elements instructional method. Experiments 1 and 3 demonstrated that when novice students are required to learn complex information, the isolated-interacting elements method of instruction was superior to the control method. In contrast, no evidence was found in Experiments 2 and 4 to suggest a difference between these instructional techniques. These contrasting results can be explained by the different levels of domain knowledge possessed by the participants of each experiment. The results of Experiment 5 were similar to those of Experiments 1 and 3, namely that students performed superiorly if they had studied the isolated elements followed by interacting elements instruction. These results provide significant theoretical support for the claim that expertise is the key factor implicated in the beneficial effects associated with the isolated-interacting elements instructional technique since the participants in Experiment 5 had previously participated in Experiments 2 and 4. The difference in the outcomes of these experiments can be explained by the level of domain specific knowledge the participants of Experiment 5 had in each of the knowledge domains tested by the various experiments.