Biomedical subjects

Chang H Lee

Publications and source records attributed to Chang H Lee.

10 recordsLinked to original sources

PubMed2007

Phonological activation in multi-syllabic sord recognition.

Three experiments were conducted to test the phonological recoding hypothesis in visual word recognition. Most studies on this issue have been conducted using mono-syllabic words, eventually constructing various models of phonological processing. Yet in many languages including English, the majority of words are multisyllabic words. English includes words incorporating a silent letter in their letter strings (e.g., champagne). Such words provide an opportunity for 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., passenger). The performance focus is on the effects of removing letters from words with a silent letter and from words with a non-silent letter. Three representative lexical tasks--naming, semantic categorization, lexical decision--were conducted in the present study. Stimuli that excluded a silent letter (e.g., champa_ne) were processed faster than those that excluded a sounding letter (e.g., passen_er) in the naming (Experiment 1), the semantic categorization (Experiment 2), and the lexical decision task (Experiment 3). The convergent evidence from these three experiments provides seminal proof of phonological recoding in multi-syllabic word recognition.

Adolescent↗

PubMed2006

Testing the two-cycle model by different word types.

The two-cycle model assumes that consonants in words are processed more quickly than vowels. This study tested the two-cycle model with different word types using a priming task which presented consonants or vowels before the target. Analysis showed presenting consonants before the target was beneficial in processing the target for the words with the letter compositions of CWC and CVCV. In contrast, presenting vowels before the target was beneficial for the words with the letter composition of VCVC. The words with the letter composition of VCCV showed no difference between the consonant prime and the vowel prime. The two-cycle model was not supported across all types of words.

Humans↗

PubMed2006

An analysis of linguistic styles by inferred age in tv dramas.

A language analysis program, Linguistic Inquiry and Word Count (LIWC), was successful in identifying various psychological variables. This study investigated the relationship between spoken language and age inferred from drama scripts of 162 characters, analyzed by the Korean-LIWC across 4 age categories (10-19, 20-39, 40-59, and 60-79 years). Analysis indicated that younger characters use fewer phrases, morphemes, nouns, auxiliary words, and adverbs than older characters, suggesting less cognitive development of younger characters. In addition, younger characters used less positive words for emotion and achievement than older characters. These data appear contrary to the negative stereotypes of aging people.

Achievement↗

PubMed2005

Behavioral and neurobiological effects of printed word repetition in lexical decision and naming.

A series of experiments studied the effects of repetition of printed words on (1) lexical decision (LD) and naming (NAM) behavior and (2) concomitant brain activation. It was hypothesized that subword phonological analysis (assembly) would decrease with increasing word familiarity and the greater decrease would occur in LD, a task that is believed to be less dependent on assembly than naming. As a behavioral marker of assembly, we utilized the regularity effect (the difference in response latency between words with regular versus irregular spelling-sound correspondences). In addition to repetition, stimulus familiarity was manipulated by word frequency and case alternation. Both experiments revealed an initial latency disadvantage for low frequency irregular words suggesting that assembly is the dominant process in both tasks when items are unfamiliar. As items become more familiar with repetition, the regularity effect disappeared in LD but persisted in NAM. Brain activation patterns for repeated words that were observed in fMRI paralleled the behavioral studies in showing greater reductions in activity under lexical decision than naming for regions previously identified as involved in assembly.

Adolescent↗

PubMed2005

Language use in emotional writing.

This brief report provides descriptive data on uses of language in emotional writing to give some dues on the mechanism of emotional writing. Two written samples, emotional writing and superficial writing, were analyzed using the program, Korean Linguistic and Word Count. Emotional writing has more complicated language structure and more cognitive words than the superficial writing.

Adult↗

PubMed2004

Differences in styles of writing about a tragic public event over time.

This pilot study analyzed the actual language used in two writing samples by university students (8 men, 28 women) about a tragic public incident, the September 11, 2001, terrorist attack. To analyze samples a computer-based text-analysis program with a wide range of psychological dimensions and linguistic variables was used. More words and more past tense verbs were used right after the incident. Words related to religion, family, and home increased dramatically right after the incident.

Humans↗

PubMed2003

Silent letters and phonological priming.

Many written English words contain silent letters. Omitting them produces nonwords pronounced identically to the original words, for example, SALM for PSALM and COLUM for COLUMN. We report two naming and two lexical decision experiments in which targets of 4-11 letters followed primes exposed for 100 ms in mask-prime-mask-target sequences. Priming in SALM-psalm and COLUM-column pairs exceeded priming in orthographic control pairs such as ASTA-pasta and COUSI-cousin, pairs in which pronounced letters are omitted to form the primes. SALM and COLUM, however, were less effective primes than PSALM and COLUMN. Results were discussed in terms of the phonological coherence hypothesis, the role of orthographic codes in filtering phonologically activated representations, and graphemes as reading units.

Humans↗

PubMed2003

Association among reading summarization, word recognition, and sentence comprehension.

Word recognition and sentence comprehension are initial and necessary processes to summarize a story. This study was conducted to investigate the relations among word recognition, sentence comprehension, and reading summarization. Analysis showed performance for word naming, an index of on-line word recognition, was correlated with the Latent Semantic Analysis scores, an index of reading summarization. These results indicate that the basic process of word recognition is a corner stone to better reading.

Cognition↗

PubMed2002

Test of the phonological recoding hypothesis using a letter-delay task.

In some English words is a silent letter in the letter strings, e.g., PSALM. This type of word provides room to manipulate phonological similarity against the words with a nonsilent letter in the corresponding position, e.g., PASTA, to test the phonological recoding hypothesis. Letter strings excluding the silent letter or the sounding letter, e.g., _salm and a phonological condition, _asta as an orthographic condition, were presented. A "psalm-type word" was processed faster than pasta-type word," indicating that phonology plays a leading role in word recognition.

Adolescent↗

PubMedDate not supplied

Reversible MR changes in the cat brain after cerebral fat embolism induced by triolein emulsion.

BACKGROUND AND PURPOSE: Clinical cerebral-fat embolism shows both reversible and irreversible changes. We used MR imaging to investigate the reversibility of embolized lesions induced with a fat-emulsion technique and to evaluate the histologic findings. METHODS: A fat emulsion was made with 0.05 mL of triolein and 20 mL of normal saline and vigorous to-and-fro movement through a three-way stopcock. In 50 cats, the internal carotid artery was infused with the fat emulsion. Cats were divided into six groups on the basis of time delay after embolization: 1 hour; 1 and 4 days; and 1, 2, and 3 weeks. MR imaging and histologic examination were performed at these times. RESULTS: Embolized lesions were hyperintense on T2-weighted images, isointense or mildly hyperintense on diffusion-weighted images, isointense on apparent diffusion coefficient maps, and enhancing on gadolinium-enhanced T1-weighted images at 1 hour. These MR imaging findings were less evident at day 1 and reverted to normal after day 4 (isointense on all images). Electron microscopy showed minimal findings in the cortical lesion in groups 1 and 2 (group 1 at 1 hour and group 2 at 1 hour and 1 day). Light microscopic findings revealed evidence of necrosis-small focal gliosis and demyelination in the periventricular white matter-in only one cat. The number of intravascular fat globules was not significantly different between groups, as visualized by oil red O staining. CONCLUSION: Cerebral-fat embolism induced by a triolein emulsion revealed reversible MR findings and minimal histologic findings.

Animals↗