• Phonetics and Speech Sciences
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• v.13 no.1
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• pp.1-15
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• 2021

The present study investigated the mental representation and processing of an ambiguous word in the bimodal processing system by manipulating the lexical ambiguity of a visually or auditorily presented word. Homonyms (e.g., '물었다') with more than two meanings and control words (e.g., '고통을') with a single meaning were used in the experiments. The lemma frequency of words was manipulated while the relative frequency of multiple meanings of each homonym was balanced. In both experiments using the lexical decision task, a robust frequency effect and a critical interaction of word type by frequency were found. In Experiment 1, spoken homonyms yielded faster latencies relative to control words (i.e., ambiguity advantage) in the low frequency condition, while ambiguity disadvantage was found in the high frequency condition. A similar interactive pattern was found in visually presented homonyms in the subsequent Experiment 2. Taken together, the first key finding is that interdependent lexico-semantic processing can be found both in the visual and auditory processing system, which in turn suggests that semantic processing is not modality dependent, but rather takes place on the basis of general lexical knowledge. The second is that multiple semantic candidates provide facilitative feedback only when the lemma frequency of the word is relatively low.

• Korean Journal of Cognitive Science
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• v.15 no.1
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• pp.35-41
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• 2004

The letter delay task using monosyllabic words has been employed in order to investigate whether Korean word is processed by the phonological route, and to investigate which stage this phonological information affects word recognition. Two main conditions were delaying a sounding letter( $\rightarrow$향), and delaying a silent letter( $\rightarrow$양). Experiment 1 was the naming task with the SOAs of 150㎳ and 250㎳ in order to investigate whether the phonological information affects the early stages, or the later stages of word recognition. The results showed that the interaction between the phonological value condition and the presence/absence of the prime was significant under the 150㎳ SOA, but not under 250㎳ SOA. Experiment 2 was conducted in order to generalize the results of Experiment 1 in the lexical decision task. The results showed the similar pattern as the Experiment 1. These experiments indicate that Korean words are processed by the phonological route, and the phonological information plays roles in the early stages of word recognition.

• Korean Journal of Cognitive Science
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• v.13 no.1
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• pp.23-40
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• 2002

This study is to examine brain regions that are involved in picture encoding in normal adults using fMRI methods. In Scan 1, the picture encoding was studied during a semantic categorization task in comparison with word. In Scan 2 task type effects were studied both during a picture naming task and during a semantic categorization task with pictures. Subjects were asked to make decision either by pressing a mouse button (Scan 1) or by responding subvocally (naming or saying yes/no) (Scan 2). Regardless of stimulus type, left prefrontal, bilateral occipital, and parietal activations were observed during semantic processing in comparison with fixation baseline. Processing of word stimulus relative to picture resulted in activations in prefrontal and parieto-temporal regions in the left side while that of picture stimulus relative to word resultd in activations in bilateral extrastriatal visual cortices and parahippocampal regions. In spite of the same task demands, stimulus-specific information processings were involved and mediated by different neural substrates; the word encoding was associated with more semantic/lexical processings than pictures and the picture processing associated with more perceptual and novelty related information processings than word. Activations of dorsal part of inferior prefrontal region, i.e., Broca's areas were found both during the picture naming and during the semantic tasks subvocally performed Especially, during the picture naming task, greater occipital activations were found bilaterally relative to the semantic categorization task. indicating a possibility that greater and higher visual processing was involved in retrieving the name referred by picture stimuli.

• Korean Journal of Cognitive Science
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• v.17 no.3
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• pp.207-229
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• 2006

Two experiments examined the relation of working memory capacity and the inhibition mechanism in working memory. Experiment 1 demonstrated that the high WM span group inhibited irrelevant information selectively and the low WM span group maintained both relevant and irrelevant information within WM. Experiment 2 showed that there were similar patterns of response time between high and low WM span groups in the lexical decision task. These results suggest that the ability to maintain relevant information and inhibit irrelevant information selectively in WM is an important factor of individual differences in working memory.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2002.05a
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• pp.131-136
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• 2002

한국어 CVC 음절의 하위 단위는 초성자음과 모음을 포함하는 음절체(body)와 종성자음(coda)으로 이루어져 있고, 영어 음절은 초성(onset)과, 모음과 종성자음을 포함하는 각운(rime)으로 이루어져 있다고 한다. 본 연구에서는 한국인이 영어의 음절을 한국어 음절 정보처리 방법으로 정보처리 하는지를 알아보고자 하였다 실험 조건으로는 음절체 일치 조건(예, 각-감, cap-cat), 각운 일치 조건(예, 남감, pat-cat), 그리고 두 자음 일치 통제조건(예, 김-감, cut-cat)과 무관련 통제 조건(예, ***-감, ***-cat)이 사용되었다. 실험 과제로는 점화 어휘판단 과제(primed lexical decision task)를 수행하였다. 만약 음절체 일치 조건에서의 점화효과가 각운 일치 조건에서의 점화효과보다 크다면 한국인의 음절분절 단위가 음절체-종성(body-coda) 구조일 것으로 예상할 수 있고 각운 조건에서의 점화효과가 더 크다면 그 단위가 초성-각운(onset-rime)구조일 것으로 예상할 수 있다. 실험 결과, 한국어 음절의 경우 각운 일치 조건의 점화 효과가 음절체 일치 조건의 점화 효과보다 크게 나타나 음절체-종성 구조로의 하위 단위 분석을 지지했다. 그러나 영어의 경우에는 각운 일치 조건의 점화 효과가 음절체 일치 조건의 점화 효과보다 크게 나타나 초성-각운 구조로의 분석을 지지하였다. 따라서 한국인이 시각 단어를 재인할 때에는 언어 특정적인 분석을 수행한다는 결과를 얻었다.

• Korean Journal of Cognitive Science
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• v.11 no.3_4
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• pp.73-81
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• 2000

This study was conducted to investigate some characteristics of representation of category knowledge and script knowledge. Using primed lexical decision task with higher level primers in the representation structure, Experiment 1 examined the interaction effects between knowledge type and concept typicality. It was found that the concept typicality has some effects in category representation, while it has no significant effect in script representation. In Experiment 2, primers of the lower hierarchy in the representation structure were employed. The results showed that the main effect of knowledge type was significant: the response time for category knowledge was faster than that for script knowledge. Typicality effect did not show in this experiment. The results of t the two experiments suggest that category knowledge is represented in hierarchy and typicality. while script knowledge may lack in that characteristics. Other aspects of the differences in characteristics of category- and script- knowledge representation were discussed,

• Annual Conference on Human and Language Technology
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• 2004.10d
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• pp.225-228
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• 2004

English has words that have a silent letter in their letter strings (e.g., knowledge). Such words provide an opportunity of investigating the role of phonological information in multi-syllabic words by comparing them to words that do not have the silent letter in the corresponding position (e.g., available). Stimuli that excluded a silent letter (e.g., _nowledge) were processed faster than those that excluded a sounding letter (e.g., _vailable) in the lexical decision task. The evidence from this experiment provides seminal evidence of phonological recoding in multi-syllabic word recognition

• Korean Journal of Cognitive Science
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• v.23 no.1
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• pp.1-23
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• 2012

This study investigated the lexical access processing of inflected Korean verbs in the mental lexicon. In Korean, verbs can be classified into two main types of inflections, which are regular and irregular inflections, which can be further divided into three types of regular inflections and two types of irregular inflections. A masked priming lexical decision task was used and the priming effects were compared. Experiments were carried out using the five different types of verbal inflections in Korean: (1) No change-regularity (regular verbs with no orthographical or phonological changes), (2) Phonological change-regularity (regular verbs with phonological changes to the stem only), (3) Orthographical change-regularity (regular verbs that only undergo orthographical changes), (4) Stem change-irregularity (the stem is omitted or alternated with the other phoneme of the stem in irregular verbs), (5) Ending change-irregularity (irregular verbs with changes in the endings by phoneme substitution). The first three types are regarded as regular verbal inflections whereas the latter two types are regarded as irregular verbal inflections. The infinitive forms of the verb were presented as target words and three different conditions were presented as prime words. The three conditions included regular verbal inflection, irregular verbal inflection, and a control condition in which morphologically and semantically unrelated primes were presented. In addition, different stimulus onset asynchrony (SOA) were manipulated (43ms, 72ms, 230ms) to examine the time frame of the morphological decomposition process in word recognition. The results revealed that there were significant priming effects in all three SOAs across conditions. Hence, there was no significant differences in priming effects between regular and irregular verbal inflection conditions. This may suggest that Korean verb processing does not adopt different processing routes for regular and irregular inflections, which can also be an indication of earlier morphological information processing for Korean verbs.

• Korean Journal of Cognitive Science
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• v.23 no.4
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• pp.487-515
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• 2012

The purpose of this study was to investigate the effect of the individual differences in cognitive processes on paragraph comprehension. To do so, the lexical decision task and the pattern comparison task were used to measure the low-level cognitive processes. Digit span task was used to test the phonological loop capacity. The individual differences of the central executive processing capacity were measured by operational span task. Reading span task was used to test the working memory capacity related with the sentence processing. Reading times and accuracies of the logically valid inferences and logically void inferences were tested to measure the high-level cognitive processes. Reading times and accuracies for the target sentences with and without prior explicit causal sentence were measured to test individuals' paragraph comprehension abilities. The results showed that the speed of the low-level cognitive processes was related with the speed of the high-level cognitive processes. Also, the accuracy of the low-level cognitive processes was related with the accuracy of the high-level cognitive processes while there was no significant correlation between the speed and the accuracy in any measures of the cognitive processes. Working memory capacity was related with the accuracy of the cognitive processes while it was not significantly correlated with the speed of the cognitive processes. Most importantly, the speed of low-level cognitive processes significantly affected the speed of the paragraph comprehension while the working memory capacity and the high-level cognitive processes had influences on the accuracies of the paragraph comprehension. The speed of the paragraph comprehension had no influence on the accuracies of the paragraph comprehension.

• Korean Journal of Cognitive Science
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• v.23 no.3
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• pp.349-366
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• 2012

Two experiments were conducted to examine the processing of Korean compounds in relation to saisios. Saisios is a letter interposed between constituents when a phonological change takes place on the onset of the first syllable of the second constituent. This saisios rule is often violated by writers, resulting in many words having two spellings: one with saisios and the other without saisios. Among two spellings, some words are more familiar with saisios, some are usually spelled without saisios, and some are balanced. In Experiment 1 using the go/no-go lexical decision task, participants were asked to judge compounds with/without saisios. Saisios-dominant words (나뭇잎 > 나무잎) were responded faster when they appeared with saisios, whereas the opposite was true for words that usually appear without saisios (북엇국 < 북어국). In experiment 2, we presented participants compound words that were balanced on saisios. The results showed that words without saisios were responded faster than words with saisios. To summarize, the results of Experiment 1 and 2 were consistent with the APPLE model. Some problems related to the saisios rule were discussed in terms of reading process.