I present evidence that masked repetition priming of word identification can be modulated by post-prime cues. Cues consisted of targets presented in black, with repetition and unrelated primes equally likely for such targets, or in a color that was correlated with type of prime (e.g., red = repetition prime, green = unrelated prime). There was an increase in response latency for targets with unrelated primes and a decrease in response latency to targets with repetition primes when target color was correlated with type of prime. In this correlation condition, subjects exhibited a larger reliance on the prime for target processing. In the condition where target color was unrelated to prime type, subjects had less reliance on the prime and processed the target more independently.

Amides are one of the most common functional groups in biological systems and in bioactive molecules. Arguably the most direct way to form amides is via the condensation of an amine onto a carboxylic acid. This reaction is notoriously difficult and has stimulated much development, including the developments of new reagents and catalysts to perform this transformation under milder conditions. More broadly, amide formation continues to be of high importance and the incorporation of emerging transformations utilizing new disconnections are complimentary to existing routes. Isocyanates are the simplest electrophiles containing the desired NCO motif and have a large presence in the polymer (e.g. polyurethane) and paint industries. In addition, isocyanates have been utilized for amide formation with various nucleophiles in a stoichiometric and catalytic fashion, but the inherent functional group intolerance associated with the high reactivity of isocyanate largely remains. Efforts have been made to address such limitations of isocyanates, including the use of a blocking group which allow for in situ release of the isocyanate while using a bench stable masked (blocked) isocyanate precursor. Changes to the blocking group structure have direct correlations to the stability and reactivity of the precursor, which helps in suppressing common side reactions observed with free isocyanates such as polymerization or oligomerization. Incorporation of a blocking group strategy in catalytic amide forming reactions has the power to unlock the potential of isocyanates with reactivity that would not be attainable with free isocyanates. Reports imparting this strategy exemplify the power of a blocking group with increased applicability and functional group tolerance compared to reactions with the free isocyanate counterpart. The implementation of this strategy for catalytic amide formation is sparse including only two reports with a rhodium catalyst. Utilization of different metals could broaden the scope of reactivity allowing for extensions that the rhodium (I) catalyst cannot do. The development of a palladium-catalyzed amide synthesis via masked isocyanates was targeted (Chapter 2). Indeed, implementation of a blocking group strategy with alkyl and aryl isocyanates allowed for efficient synthesis of amides with electron rich and mildly deficient aryl boroxine nucleophiles. Catalysis was achieved with 1 mol% of Pd(OAc)2 and 2 mol% of SPhos at 50 ℃ with Et3N to aid in the deblocking of the isocyanate. Several control experiments were iii conducted to obtain mechanistic insight including what mechanism may be operative as well as the necessity of this blocking group strategy. Kinetic studies were performed using the variable time normalization analysis method and have yielded the following information: 1) the presence of catalyst decomposition, 2) that the rate determining step involved the catalyst, boroxine, and masked isocyanate, and 3) that the rate determining step is likely the insertion into the isocyanate. In summary, palladium catalysts can achieve catalysis with masked isocyanates to facilitate amide formation under appropriate conditions. With limited reports of masked isocyanates in catalysis, this reactivity could act as a steppingstone for developments of reactivity that are held back with the use of free isocyanates.

The purpose of this dissertation is to investigate the extent to which there is consistent evidence pertaining to the prime lexicality effect. Theoretical claims about the nature of this effect, in which masked nonword form primes produce greater facilitation than word form primes, have been hotly debated in the masked priming literature. Here, there are two major conflicting accounts of visual word recognition to consider. Cascaded activation approaches such as the Interactive Activation model rely on competition between word units to account for word recognition. This view predicts inhibitory effects for word form primes due to competition between word units for the prime and target. In contrast, proponents of the Search Model have maintained that elements in the process of verifying visual input suggest that word primes should produce neither facilitatory nor inhibitory effects during masked presentation. Evidence that is consistent with both approaches has been reported in the literature. A 1998 study by Forster and Veres looked at long words using a masked lexical decision task and demonstrated strong facilitation from nonword primes and no effect for word primes. A 2006 paper for Davis and Lupker, however, reported that the nonword prime facilitation that they observed using the same task was accompanied by strong word prime inhibition. The presence of this inhibitory effect seems to support the interactive activation account, but it remains unclear why inhibitory effects such as these were not seen in the Forster and Veres work. The present study sought to explore the reliability of the effects that are generated by word form primes. In particular, the different types of stimuli used in the conflicting papers (i.e. long versus short items) were contrasted. Evaluations regarding their relative discrimination difficulty and performance during masked lexical decision were conducted. The investigation revealed that there is indeed a difference between the output provided by those different stimulus types and that context effects emerge when they are presented together in the same experiment. The implications of these findings for the various views on visual word recognition are discussed.

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Sound transmission devices have advanced filtering abilities that theoretically protect the ear from harmful Masking noise while amplifying the sounds that need to be heard, such as backup alarms. Therefore, such devices should provide improved signal detection in noise when compared to their passive counterparts. The masked threshold of a vehicular backup alarm was determined for audiometrically normal and non-normal hearers using two types of sound transmission devices and their passive counterparts within pink noise and milling machine noise at intensities of 75, 85, 95 and 105 dBA. Results indicated that the sound transmission devices did not have any statistically significant advantages over the passive devices with respect to masked threshold of a backup alarm. Therefore, it cannot be concluded that these devices offer advantage over similar passive devices with respect to signal detection. Additionally, ratings of comfort and the ability to detect the alarm for each device were gathered. Both scales did not show any significant differences between the two device types. / Master of Science

There are now extensive behavioral and neuropsychological evidence to indicate that semantic information of a word can be activated without conscious awareness. However, semantic activation alone may not be sufficient for observing semantic priming effects in masked lexical decision task. In the following study, two tasks were used: lexical decision and semantic categorization. Conscious awareness of the prime was systematically manipulated by varying the duration of the prime and by varying the placement of the mask in the prime-target presentation sequence. Priming effects were observed in the semantic categorization task at prime durations of 42 milliseconds but no semantic priming was observed for the same prime duration in the lexical decision task. However, semantic priming effects began to emerge in lexical decision at the longer prime durations (55 & 69 ms) and under the least effective prime-mask presentation sequences. It is proposed that semantic activation alone is not sufficient for semantic priming effects in the lexical decision task but that central executive involvement is necessary, if only at the lowest level, for facilitatory effects to be observed. Furthermore, no such central executive involvement appears to be required for the semantic categorization task. The priming effects obtained in this task is interpreted in terms of a "decision priming" effect.

Syftet med föreliggande studie var att undersöka hur bra vi är på att bedöma ålder på omaskerade och maskerade ansikten. Syftet var även att undersöka om det fanns systematiska fel som är förknippade med åldersbedömning av maskerade ansikten. Totalt fick 60 försöksdeltagare, samtliga ungdomar, skatta åldern på 60 fotografier av 30 maskerade och 30 omaskerade män.  Fotografierna var indelade i två åldersgrupper, yngre och äldre, och samtliga stimulipersoner förekom i både den maskerade och den omaskerade varianten. Resultaten visade att försöksdeltagarna var bättre på att skatta åldern på omaskerade ansikten än på maskerade. Inga skillnader i systematiska fel fans mellan maskerade och omaskerade ansikten. Bilder av unga ansikten skattades med högre precision än bilder av äldre ansikten. / The purpose of this study was to investigate how well we are at age estimations of masked and unmasked faces. The purpose was also to investigate if there were any biases that effected age estimations of masked faces. A total of 60 participants, all juveniles, estimated the age of 60 photographs of 30 masked and 30 unmasked men. The photographs were divided into two age groups, younger and older, and all of the men, who served as stimuli, were represented in both conditions. The results showed that the participants were better at estimating the age of unmasked than masked faces. There were no differences in biases between masked and unmasked faces. Photographs of young faces were estimated with greater precision than older faces.

Letter position plays an important role in lexical access. But are some positions more important than the others? Findings from numerous studies support the notion that in lexical access, initial letters produce strongest activation, which weakens towards the end of the word. In order to create a metric for computing the activation produced by each letter position in a correctly spelled word versus a word in which some or all letters are transposed, the formula for calculating a word's orthographic match coefficient (OMC) was developed and tested. Utilizing the masked priming paradigm and a lexical decision task, Experiments 1-5 test the accuracy and reliability of the OMC predictions, and look at neighborhood density in conjunction with different types of letter movement. Results from these experiments provide empirical support for the OMC as a reliable predictor of priming that involves transposed letters, and offer insight into possible mechanisms of word recognition.

Most research in word recognition uses words that already exist in the reader's lexicon, and it is therefore of interest to see whether newly learned words are represented and processed in the same way as already known words. For example, are newly learned words immediately represented in a special form of lexical memory, or is there a gradual process of assimilation? As for L2 language learners, are newly learned words incorporated into the same processing system that serves L1, or are they represented quite independently?The current study examines this issue by testing for the existence of the Prime Lexicality Effect (PLE) observed in masked priming experiments (Forster & Veres, 1998). Strong form priming was found with nonword primes (e.g., contrapt-CONTRACT), but not with word primes (e.g., contrast-CONTRACT). This effect is generally assumed to result from competition between the prime and the target. So if the readers had been trained to treat "contrapt" as a new word, would it now function like a word and produce much weaker priming? Elgort (2007) demonstrated such an effect with unmasked primes with L2 bilinguals. The current study investigates the PLE in both L1 and L2 bilinguals under different training conditions. When the training program involves mere familiarization (learning to type the words), a PLE was found with visible primes, but not with masked primes, which suggests that unmasked PLE is not the best indicator of lexicalization. In the case of "real" acquisition where the new word is given a definition and a picture of the object it refers to, and learning is spread over two weeks, a clear PLE was obtained. However, when the same experiment was carried out on Chinese-English bilinguals using the same English materials, completely opposite results were obtained. The learning enhanced priming, rather than reducing it, suggesting that the L2 lexicon might differ qualitatively from the L1 lexicon. The implications of these results for competitive theories of lexical access are discussed, and alternative explanations are considered.

This dissertation focuses on the unique aspects of Maltese morphology brought about by its genetic and geographic history. The experiments conducted and described here build on past research in Indo-European languages and new research in other Semitic languages to determine how different word formation systems function. Applying experimental techniques to the study of Maltese is crucial for two reasons. First, though Maltese is a Semitic language, recent extensive contact with English has greatly impacted its vocabulary and the structure of its verbs. Though the effects of persistent language contact is pervasive, clear and systematic differences may be observed between native Semitic verbs and those borrowed from English. Secondly, unlike other Semitic languages, the Maltese writing system uses the Roman alphabet. This allows for tests that require the reading of written stimuli to be performed in the same writing system as previous studies in Indo-European languages, eliminating a number of confounding factors.A masked priming experiment asked Maltese speakers to judge whether or not test items were words of their language. The test items included real and nonce verbs of both Semitic and English origin. Accuracy rates and reaction time were recorded and compared across speakers. The results of this experiment support the psychological salience of the consonantal root as a unit of lexical organization.An elicitation experiment asked native speakers of Maltese to provide a verb form that corresponded to a given noun or adjective. The test items were nouns of Semitic and English origin and non-words constructed to resemble such nouns. Responses were broadly transcribed and analyzed for their similarity to the expected patterns. The results show that speakers are able to use two morphological strategies to form new words. The factors affecting the choice between morphological systems include linguistic structure and social variables.Collectively, this pair of experiments indicate that the consonantal root is a viable morphological and psychological unit of lexical organization, supporting a search-based approach to lexical access. Furthermore, speakers are able to form new words on the basis of whole words, showing that this level of organization must also be present to facilitate lexical access.