Biomedical subjects

A Schepman

Publications and source records attributed to A Schepman.

4 recordsLinked to original sources

PubMed2000

The effects of cigarette smoking on negative priming.

Nicotine administration has been found to enhance performance on tasks of selective attention. It has been proposed that efficient attentional filtering depends on the successful inhibition of distracting information. In the work reported here, a negative priming paradigm was adopted to test whether smoking enhanced the inhibition of irrelevant information. Thirty-six minimally deprived smokers, half of whom smoked and half of whom sham smoked, completed the negative priming task. A significantly larger negative priming effect was found in participants who had smoked in comparison with those who sham smoked. These results support the hypothesis that nicotine enhances the inhibition of distracting information and thus suggest a possible mechanism by which smoking may enhance selective attention.

Adolescent↗

PubMed2000

Prosody and parsing in coordination structures.

The effect of prosodic boundary cues on the off-line disambiguation and on-line parsing of coordination structures was examined. It was found that relative clauses were attached to coordinated object noun phrases in preference to second conjuncts in sentences like: The lawyer greeted the powerful barrister and the wise judge who was/were walking to the courtroom. Naive speakers signalled the syntactic contrast between the two structures by a prosodic break between the conjuncts when the relative clause was attached to the second conjunct. Listeners were able to use this prosodic information in both off-line syntactic disambiguation and on-line syntactic parsing. The findings are compatible with a model in which prosody has a strong immediate effect on parsing. It is argued that the current experimental design has avoided confounds present in earlier studies on the on-line integration of prosodic and syntactic information.

Cues↗

PubMed2000

Phonological conditioning of peak alignment in rising pitch accents in Dutch.

This paper deals with the factors that influence the alignment of F0 movements with phonetic segments. It reports two experiments on the alignment of rising prenuclear pitch accents in Dutch. In experiment 1, it is shown that the final peak of the rise is aligned at the end of the vowel if the accented syllable contains a long vowel, but during the following consonant if the accented syllable contains a short vowel. The beginning of the rise is consistently aligned at the beginning of the accented syllable. Experiment 2 attempts to distinguish between two explanations for this finding: (1) a durational account, in which the F0 rise takes a certain amount of time and overruns into the following consonant if the vowel is short; and (2) a structural account, in which the peak of the rise is seen as a tonal target aligned with the end of the syllable (which is structurally earlier for long vowels than for short vowels). The data partially support both accounts. There is an alignment difference despite a lack of durational difference, which supports the structure-based account. However, the effect is reduced compared to experiment 1, showing that time pressure may work against the ideal alignment.

Conditioning, Psychological↗

PubMed1999

Constant "segmental anchoring" of F0 movements under changes in speech rate.

This study develops the notion of the "segmental anchoring" of F0 movements, specifically, the finding that both the beginning and the end of a rising pitch accent are anchored to specific points in segmental structure [Arvaniti et al., J. Phonetics 26, 3-25 (1998)]. If there are segmental anchors for rising accents (and if, as shown by Arvaniti et al., the F0 level of the beginning and ending points is unaffected by the experimental manipulations), the anchors should be closer together as the speaking rate increases, and the rises should therefore be shorter and steeper. This was tested in two experiments in which speakers were asked to modify rate. The first experiment confirmed the basic prediction that the duration of accentual F0 rises is affected by changes in rate. The second experiment studied the alignment of the beginning and ending points with their hypothesized segmental anchors. For all speakers there was a strong correlation between the duration of the rise and the time interval between the anchors, but only small and inconsistent effects of rate on alignment. Effects of rate on F0 excursion size were likewise small and inconsistent. The results support a model in which pitch accents consist of "tonal targets," and in which the alignment and F0 level of tonal targets are what determine a pitch accent's shape.

Adult↗