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Biomedical subjects

L B Feldman

Publications and source records attributed to L B Feldman.

At least 19 recordsLinked to original sources
PubMed2001

Morphological facilitation following prefixed but not suffixed primes: lexical architecture or modality-specific processes?

Morphological facilitation was examined in immediate (Experiment 1) and long-term (Experiment 2) lexical decision with English materials. For the target (payment), related primes consisted of base-alone (pay), affix-plus-base (prepay), or base-plus-affix (payable) combinations, thereby defining position of overlap. In addition, modality of presentation varied for primes and targets (Experiment 1). At short lags, the advantage for prepay-payment over payable-payment type pairs was significant when primes were visual (V) and targets were auditory (A), marginal under AV conditions, and nonexistent under VV conditions. At long lags, the magnitude of VV did not vary with position of overlap. Morphological facilitation was stable across changes in modality following prefixed and simple forms, reflecting lexical architecture. By contrast, the absence of facilitation following suffixed primes presented cross-modally implicates modality-specific processing.

Adult↗
PubMed2000

Are morphological effects distinguishable from the effects of shared meaning and shared form?

Effects of orthographically and semantically related primes were compared with morphologically related primes in an immediate (Experiment 1) and a long-term (Experiment 2) lexical decision task. Morphological relatedness produced facilitation across a range of prime durations (32-300 ms) as well as when items intervened between prime and target, and its magnitude increased with prime duration. Semantic facilitation and orthographic inhibition arose only in the immediate priming task. Moreover, morphological effects were significantly greater than the sum of semantic and orthographic effects at a stimulus onset asynchrony of 300 ms but were not reliably different at shorter durations. The adequacy of an account that describes morphological relatedness as distinct from the composite effects of semantic and orthographic similarity must account for changes in additivity across prime durations.

Adolescent↗
PubMed1997

The role of component function in visual recognition of Chinese characters.

M. Taft and X. Zhu (1997) reported that character decision latencies to real Chinese characters containing components that entered into many combinations were faster than decision latencies to characters with components that entered into only a small number of combinations. However, this effect was restricted to components that appeared on the right side of Chinese characters. In written Chinese, phonetic components tend to appear on the right, and semantic components tend to appear on the left. Therefore, in Taft and Zhu's study, there was the possibility of a confound between position (left vs. right) and function (semantic vs. phonetic). Results of the present experiment show combinability effects for components with semantic and with phonetic functions. Counter to the claim by Taft and Zhu that component frequency effects are constrained by position, when component function was considered, character decision latencies varied with component frequency but not reliably with position.

Adult↗
PubMed1995

Decomposing words into their constituent morphemes: evidence from English and Hebrew.

Participants segmented and shifted a sequence of letters from a source word to a target word and then named the product aloud. Morphemic and nonmorphemic letter sequences (e.g., EN) from phonemically matched words such as HARDEN and GARDEN were compared. In 4 experiments, naming latencies were faster for morphemic sequences than their nonmorphemic controls in both English, in which the morphemic status of the shifted sequence was varied and sequences were appended after the base morpheme (linearly concatenated), and in Hebrew, in which morphological transparency of the root (base morpheme) was varied and 1 morpheme was infixed inside the other (nonconcatenative) so that the phonological and orthographic integrity of the morphemic constituents was disrupted. Moreover, the likelihood with which both affixes and bases combine to form words influenced segment shifting times. In conclusion, skilled readers are sensitive to the morphological components of words whether or not they form contiguous orthographic or phonological units.

Humans↗
PubMed1994

Morphological analysis of disrupted morphemes: evidence from Hebrew.

In concatenative languages such as English, the morphemes of a word are linked linearly so that words formed from the same base morpheme also resemble each other along orthographic dimensions. In Hebrew, by contrast, the morphemes of a word can be but are not generally concatenated. Instead, a pattern of vowels is infixed between the consonants of the root morpheme. Consequently, the shared portion of morphologically-related words in Hebrew is not always an orthographic unit. In a series of three experiments using the repetition priming task with visually presented Hebrew materials, primes that were formed from the same base morpheme and were morphologically-related to a target facilitated target recognition. Moreover, morphologically-related prime and target pairs that contained a disruption to the shared orthographic pattern showed the same pattern of facilitation as did nondisrupted pairs. That is, there was no effect over successive prime and target presentations, of disrupting the sequence of letters that constitutes the base morpheme or root. In addition, facilitation was similar across derivational, inflectional and identical primes. The conclusion of the present study is that morphological effects in word recognition are distinct from the effects of shared structure.

Humans↗
PubMed1991

The contribution of morphology to word recognition.

Evidence of morphological processing was investigated in three word recognition tasks. In the first study, phonological ambiguity of the base morpheme in morphologically complex words of Serbo-Croatian was exploited in order to evaluate the claim that the base morpheme serves as the unit by which entries in the lexicon are accessed. An interaction of base morpheme ambiguity and affix characteristics was obtained and this outcome was interpreted as evidence that all morphological constituents of a word participate in lexical access. In the second study, facilitation due to morphological relatedness of prime and target was observed with Serbo-Croatian materials in the lexical decision and naming versions of the repetition priming task and results were interpreted as evidence of a morphological principle of organization among whole-word forms in the lexicon. In the third study, morphological affixes of both English and Serbo-Croatian words were segmented from a source word and affixed to a target word more rapidly than phonemically matched controls. Results suggest that the morphological constituents of complex words are available in some word recognition tasks and that morphological knowledge is represented in the speaker's lexicon.

Attention↗
PubMed1990

Phonological ambiguity and lexical ambiguity: effects on visual and auditory word recognition.

Three experiments in Serbo-Croatian were conducted on the effects of phonological ambiguity and lexical ambiguity on printed word recognition. Subjects decided rapidly if a printed and a spoken word matched or not. Printed words were either phonologically ambiguous (two possible pronunciations) or unambiguous. If phonologically ambiguous, either both pronunciations were real words or only one was, the other being a nonword. Spoken words were necessarily unambiguous. Half the spoken words were auditorily degraded. In addition, the relative onsets of speech and print were varied. Speed of matching print to speech was slowed by phonological ambiguity, and the effect was amplified when the stimulus was also lexically ambiguous. Auditory degradation did not interact with print ambiguity, suggesting that perception of the spoken word was independent of the printed word.

Adult↗
PubMed1990

The contribution of morphological and semantic relatedness to repetition priming at short and long lags: evidence from Hebrew.

The effect of morphological repetition at lag 0 and at lag 15 on lexical decision was investigated in Hebrew with three types of relation between prime and target. In the semantic-plus-morphological condition (SM), the prime and the target in each pair were two semantically related derivatives of the same root. In the "pure morphological" condition (M), the prime and the target derived from the same root, but their semantic association was very low, or non-existent. In the semantic priming condition (S), primes and targets were semantically associated but were not morphologically related. The pure semantic relationship produced a significant facilitation at lag 0 that disappeared completely at lag 15. The pure morphological relation produced (smaller but) significant facilitation at lag 0 that was not attenuated at lag 15. When prime and target were semantically as well as morphologically related, the facilitation at lag 0 was similar to semantic priming, whereas at lag 15 it was similar to the pure morphological effect. Significant repetition effects at both lags were also found with non-words that shared the same (nonsensical) root and differed with respect to real derivational affixes. The differential time course for facilitation due to semantic and morphological relatedness suggests distinct underlying processes, although at lag 0 it is possible that semantic relatedness may augment the morphological repetition effect. Morphological repetition probably facilitates the retrieval of lexical information that, under certain circumstances, is necessary for lexical decision.

Adult↗
PubMed1989

Suicidal persons and their partners: individual and interpersonal dynamics.

The individual and interpersonal dynamics of 21 suicidal persons (15 females and 6 males) and their partners were investigated. Each couple was interviewed at the time of the suicidal person's psychiatric hospitalization following a recent episode of suicidal behavior or serious suicidal ideation. Each partner was administered two tests of individual functioning and one test of interpersonal functioning. The results revealed that the dynamics of these couples were characterized by complementarity at the level of overt individual functioning, and similarity at the level of covert individual functioning. Both partners in a couple tended to describe the suicidal partner as psychologically disabled and the nonsuicidal partner as well-functioning. However, the suicidal patients and their partners were similar in terms of covert individual functioning both showing a tendency toward anclitic, dependent object relations. The communication between the partners was found to be disturbed in a large majority of the couples. The implications of these findings are discussed in terms of an integrative model of individual and interpersonal dynamics.

Adult↗
PubMed1989

Language specificity in lexical organization: evidence from deaf signers' lexical organization of American Sign Language and English.

A sign decision task, in which deaf signers made a decision about the number of hands required to form a particular sign of American Sign Language (ASL), revealed significant facilitation by repetition among signs that share a base morpheme. A lexical decision task on English words revealed facilitation by repetition among words that share a base morpheme in both English and ASL, but not among those that share a base morpheme in ASL only. This outcome occurred for both deaf and hearing subjects. The results are interpreted as evidence that the morphological principles of lexical organization observed in ASL do not extend to the organization of English for skilled deaf readers.

Cues↗
PubMed1987

Repetition priming is not purely episodic in origin.

The sufficiency of similarity among surface attributes of prime-target pairs to account for the pattern of facilitation obtained in the repetition priming paradigm was evaluated. In Experiment 1, morphological primes were singular, inflected case forms of Serbo-Croatian words and visual similarity of prime and target was manipulated by alternating the two alphabets in which the Serbo-Croatian language is written. Results indicated that the magnitude of facilitation in the alphabetically alternating condition was not reduced relative to the nonalternating condition (RUPI-RUPI vs. RUPI-RUPI) which suggested that visual similarity is not a necessary condition for facilitation in the present task. In Experiment 2, related pairs included (a) base forms with diminutives, a class of highly productive and semantically predictable derivations marked in Serbo-Croatian by suffixes and (b) base words with morphologically unrelated monomorphemic words whose orthographic pattern encompassed the target in initial position and a sequence of letters in final position that elsewhere functions as a diminutive suffix. No facilitation of word targets by orthographically similar but morphologically unrelated primes was observed although there was a tendency toward facilitation among structurally similar pseudowords. Collectively, the experiments suggested that structural similarity of prime and target is not a sufficient condition for facilitation in the repetition priming paradigm.

Humans↗
PubMed1986

Structure and expression of the murine N-myc gene.

We have demonstrated that the entire murine N-myc gene and the sequences necessary for its expression in human neuroblastoma cells are contained within a 7.4-kilobase murine genomic clone. The complete nucleotide sequence of this gene reveals a number of striking similarities and differences when compared to the related c-myc gene including the following: (i) each gene contains three exons of which the first encodes a long 5'-untranslated leader sequence; (ii) the coding regions of the N- and c-myc genes share regions of substantial nucleic acid homology, the putative N-myc protein shares substantial homology with the c-myc protein; (iii) as with c-myc, extensive nucleotide sequence homology exists between the untranslated regions of the human and murine N-myc gene transcripts; however, the N-myc and c-myc untranslated regions are totally divergent; (iv) the N-myc transcriptional promoter differs from that of c-myc and is more related to the promoter of the simian virus 40. We discuss these findings in the context of previously defined similarities and differences in the potential functional and regulatory aspects of these two myc-family members.

Animals↗
PubMed1986

Tailor-made monoclonal antibodies.

Monoclonal antibodies, potentially powerful diagnostic and therapeutic reagents, are having a significant impact in basic and clinical research. Some persisting problems must be solved, however, in order to realize the potential of this technology. We review the basic biology of antibody molecules and the genes that encode them, and discuss how this knowledge can be applied to make more effective monoclonal antibodies.

Amino Acid Sequence↗
PubMed1985

Effects of phonological ambiguity on beginning readers of Serbo-Croatian.

Third- and fifth-grade Yugoslavian children rapidly named familiar words and unfamiliar pseudowords that were written either in the Roman alphabet or in the Cyrillic alphabet and that were either phonologically ambiguous or not. Phonological ambiguity was produced by using letter strings that, when transcribed in Roman or when transcribed in Cyrillic, contained one or more ambiguous characters. Ambiguous characters are those letters shared by the two alphabets that receive different phonemic interpretations in the two alphabets. The controls for phonologically ambiguous words were the same words in their alternative, nonambiguous alphabetic transcription. Consistent with previous experiments on adults, the phonologically ambiguous form of a word or pseudoword was named much more slowly than the phonologically unambiguous form. For children who were equally proficient in both Roman and Cyrillic, the effect of phonological ambiguity was greater as children named letter strings faster. If it can be assumed that reading fluency correlates with naming latency, then it can be argued that the better beginning reader is more phonologically analytic.

Child↗
PubMed1983

Word recognition in Serbo-Croatian is phonologically analytic.

A lexical-decision task was conducted with bialphabetic readers of Serbo-Croatian. It was shown that letter strings that can be assigned both a Roman and a Cyrillic alphabet reading incur longer latencies than does the unique alphabet transcription of the same word. This within-word phonological-ambiguity effect was obtained for both words and pseudowords, but the effect was more exaggerated with words. In addition, the magnitude of the difference depended on the number and distribution of ambiguous characters in the ambiguous letter string. It was concluded that lexical decision in Serbo-Croatian necessarily involves a phonologically analytic strategy.

Adolescent↗
PubMed1983

Relation between pronunciation and recognition of printed words in deep and shallow orthographies.

The processes responsible for recognition and pronunciation of printed words were studied by means of lexical decision and naming experiments. Two languages were examined: English, which has a complex and deep correspondence between spelling and speech, and Serbo-Croatian, in which the correspondence is simple and direct. It was hypothesized that reliance on articulatory coding (instead of on mediation by the internal lexicon) would be greater for Serbo-Croatian because its shallow orthography would allow more efficient use of spelling-to-speech correspondences. Each target stimulus was preceded by a word that was either related or unrelated semantically. Semantic priming of target words facilitated performance in both lexical decision and naming for English, results suggesting an influence of the internal lexicon on both processes. In contrast, semantic priming facilitated only lexical decision for Serbo-Croatian, which suggests that naming, at least in that language, is not strongly influenced by the internal lexicon. Further, in Serbo-Croatian, lexical decision and naming latencies were correlated when both tasks were not semantically primed and were uncorrelated when either or both tasks received semantic priming. This suggested that articulatory coding is used in lexical decision, at least under conditions in which contextual semantic facilitation is absent. In contrast, in English, lexical decision and naming were correlated uniformly whether semantic facilitation was present or not, which, when considered with the effect of semantic facilitation on naming, suggested a stronger influence of the internal lexicon on both recognition and pronunciation.

Form Perception↗