Biomedical subjects

R Frost

Publications and source records attributed to R Frost.

At least 37 records · Page 2Linked to original sources

PubMed1997

Planned duration of residential drug abuse treatment: efficacy versus effectiveness.

AIMS: Two randomized controlled trials of residential drug abuse treatment programs found the programs to be equally effective, based on outcomes among those assigned to the treatments. This study aimed to compare the relative efficacy of the programs, based on outcomes among those who received the specific treatment program as planned. DESIGN: Secondary analyses of data from two concurrent randomized controlled trials, with stratification by actual length of stay. SETTING: Two residential drug abuse treatment facilities in the United States. PARTICIPANTS: Six hundred and twenty-eight clients were enrolled over a 2-year period, representing 85% of all clients admitted, 91% of all eligible clients, and 95% of those asked to participate. INTERVENTIONS: At one facility, clients were randomized to 3-month or 6-month versions of a traditional therapeutic community program. At the second facility, clients were randomized to 3-month or 6-month versions of a modified therapeutic community program that emphasized relapse prevention and health education. MEASUREMENTS: Time from admission to first drug use (except alcohol); and Addiction Severity Index (ASI) composite scores for severity of drug, alcohol, legal, and employment problems. FINDINGS: Five hundred and thirty-nine clients (86%) completed a follow-up interview at least 16.5 months after admission. In the relapse prevention trial, benefits of the 6-month program were generally limited to those who stayed at least 40 days. In the therapeutic community trial, among those who stayed at least 171 days, the 12-month program had a beneficial effect on employment. Otherwise, there were inconsistent differences between the 6- and 12-month programs. CONCLUSIONS: On average, clients who stayed in treatment at least 80 days benefited from continuing in treatment for up to 6 months, but not beyond. Conversely, those admitted to programs of longer planned duration who dropped out of treatment early had worse outcomes than those who dropped out of shorter programs. Thus, although longer planned duration of treatment may be efficacious, it is not effective.

Adult↗

PubMed1996

The Yale-Brown Obsessive Compulsive Scale: interview versus self-report.

Several studies have demonstrated the reliability and validity of the Yale-Brown Obsessive Compulsive Scale (YBOCS) conducted by trained interviewers. The present study examined several aspects of a self-report YBOCS version relative to the usual interview format in two non-clinical samples (ns = 46 and 70) and in a clinical OCD sample (n = 36) and a clinical non-OCD group (n = 10). The self-rated instrument showed excellent internal consistency and test-retest reliability, performing somewhat better than the interview. There was good agreement between symptom checklist categories across the two versions, though clinical subjects reported more symptoms on the self-report form than on the interview. Some order effects were evident for non-clinical subjects only: those who received the self-report first scored lower on both self-report and interview than those who received the interview first. No order effects were observed in the clinical sample. The self-report version showed strong convergent validity with the interview, and discriminated well between OCD and non-OCD patients. Although more study is needed, particularly on clinical samples, these findings suggest that the self-report YBOCS may be a time-saving and less costly substitute for the interview format in assessing OCD symptoms.

Adolescent↗

PubMed1996

Changes in HIV risk behavior following alternative residential programs of drug abuse treatment and AIDS education.

We compared the effectiveness in changing human immunodeficiency virus (HIV) risk behavior of two different approaches to acquired immunodeficiency syndrome (AIDS) education given by residential drug abuse treatment programs differing in their planned duration. Two randomized controlled trials compared (a) a 6-month with a 12-month therapeutic community (TC) program, and (b) a 6-month with a 3-month relapse prevention (RP) program. Three composite variables assessing HIV risk (a) drug injection, (b) sexual partners, and (c) condom use-were measured for the 3 months prior to admission and follow-up. The TC program comprised a four-part AIDS information intervention. The RP program comprised a 21- or 42-session small-group program in the principles of RP, 5 skills-building AIDS education sessions, and 6 other health education sessions. Four hundred ninety-five clients were enrolled in the study and completed a follow-up interview within 6 months of exit (79% of those enrolled). Clients in the RP program reduced their drug injection and condom use risk. Female clients in the TC program reduced their condom use risk. There were no differential effects on risk behavior change of either planned duration (randomization assignment) or program type (RP versus TC). Thus, differences in the treatment programs, including AIDS education components, had no apparent effect on HIV risk behavior change. The contribution of residential drug abuse treatment programs to AIDS prevention remains unproved.

Adult↗

PubMed1996

Planned versus actual duration of drug abuse treatment. Reconciling observational and experimental evidence.

The purpose of the study was to evaluate the associations of planned versus actual duration of drug abuse treatment with psychosocial outcomes and drug use at follow-up. A randomized trial was conducted in a modified therapeutic community in which 444 clients were assigned to programs with planned durations of either 3 or 6 months. Outcomes were psychosocial measures assessing changes in mood and in stage of behavior change between admission and exit and return to drug use and patterns of use 2 to 6 months after exit. Planned duration was not associated with any of the outcomes. A longer actual length of stay was, however, associated with greater improvements in the mood variables; lower rates of drug use at follow-up; and, among those using drugs at follow-up, a longer time from exit to first drug use. Intention-to-treat analyses supported these results. Randomized controlled trials are needed to distinguish the effects of planned duration and actual length of stay.

Adult↗

PubMed1996

Is an apple a fruit? Semantic relatedness as reflected by psychophysiological responsivity.

In the present study, we investigated orienting response generalization across various types of semantically related stimuli. Four experiments, based on a modified version of the guilty knowledge technique, were designed to examine whether semantic relations based on abstract features are reflected by electrodermal responsivity. No generalization across coordinates was obtained, but a moderate degree of generalization was demonstrated between a word and its superordinate category (e.g., table-furniture) and between a word and its synonym. Complete generalization occurred from a verbal label of an object to its pictorial representation, and vice versa. These results are compatible with our proposal that partial identification of the test stimulus as relevant is a necessary condition for generalization in the guilty knowledge technique.

Adult↗

PubMed1995

Phonological computation and missing vowels: mapping lexical involvement in reading.

The role of assembled versus addressed phonology in reading was investigated by examining the size of the minimal phonological unit that is recovered in the reading process. Readers named words in unpointed Hebrew that had many or few missing vowels in their printed forms. Naming latencies were monotonically related to the number of missing vowels. Missing vowels had no effects on lexical decision latencies. These results support a strong phonological model of naming and suggest that even in deep orthographies, phonology is not retrieved from the mental lexicon as a holistic lexical unit but is initially computed by applying letter-to-phoneme computation rules. The partial phonological representation is shaped and completed through top-down activation.

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↗

PubMed1995

The effectiveness of alternative planned durations of residential drug abuse treatment.

Randomized controlled trials were conducted at two residential drug abuse treatment facilities to compare programs that differed in planned duration. One trial compared a 6-month and a 12-month therapeutic community program (n = 184), and the second compared a 3-month and a 6-month relapse prevention program (n = 444). Retention rates over comparable time periods differed minimally by planned treatment duration, and the longer programs had lower completion rates. There was no effect in either trial of planned treatment duration on changes in psychosocial variables between admission and exit or on rates or patterns of drug use at follow-up between 2 and 6 months after exit.

Follow-Up Studies↗

PubMed1994

The relationships of HIV status and HIV risky behavior with readiness for treatment.

We investigated the associations of self-reported HIV status and risky injection practices with dependent variables measuring readiness and motivation for treatment and depression among 550 clients at two residential drug abuse treatment programs. The results suggest that a positive HIV status may be associated with motivation for treatment independently of and more strongly than risky behavior. In multivariable analyses, HIV status was associated with a scale measuring cons of drug use (P = 0.006). Risky behavior was associated with the dependent variables only in univariate analyses. The univariate association between risky behavior and depression was confounded by social desirability bias. Further research is needed to determine whether HIV-related variables predict retention or outcome of treatment.

AIDS Serodiagnosis↗

PubMed1994

Prelexical and postlexical strategies in reading: evidence from a deep and a shallow orthography.

The validity of the orthographic depth hypothesis (ODH) was examined in Hebrew by employing pointed (shallow) and unpointed (deep) print. Experiments 1 and 2 revealed larger frequency effects and larger semantic priming effects in naming with unpointed print than with pointed print. In Experiments 3 and 4, subjects were presented with Hebrew consonantal strings that were followed by vowel marks appearing at stimulus onset asynchronies ranging from 0 ms (simultaneous presentation) to 300 ms from the onset of consonant presentation. Subjects were inclined to wait for the vowel marks to appear even though the words could be named unequivocally using lexical phonology. These results suggested that prelexical phonology was the default strategy for readers in shallow orthographies, providing strong support for the ODH.

Adult↗

PubMed1993

Phonetic recoding of phonologically ambiguous printed words.

Speech detection and matching simultaneously presented printed and spoken words were used to examine phonologic and phonetic processing of Hebrew heterophonic homographs. Subjects detected a correspondence between an ambiguous letter string and the amplitude envelopes of both dominant and subordinate phonological alternatives. Similar effects were obtained when the homographs were phonologically disambiguated by adding vowel marks. The matching of the unpointed printed forms of heterophonic homographs to the dominant and subordinate spoken alternatives presented auditorily was as fast as matching the pointed unambiguous forms to the respective spoken words. This outcome was not obtained when print and speech were not presented simultaneously. These results suggest that printed heterophonic homographs activate the two spoken alternatives they represent and provide further confirmation for fast phonetic recoding in reading.

Acoustic Stimulation↗

PubMed1992

Processing phonological and semantic ambiguity: evidence from semantic priming at different SOAs.

Disambiguation of heterophonic and homophonic homographs was investigated in Hebrew using semantic priming. Ambiguous primes were followed by unambiguous targets at 100 ms, 250 ms, and 750 ms stimulus onset asynchrony (SOA). Lexical decision for targets related to the dominant phonological alternatives of heterophonic homographs were facilitated at all SOAs. Targets related to subordinate alternatives were facilitated only at SOAs of 250 ms or longer. When the primes were homophonic homographs, semantic relationship facilitated lexical decision of targets at all SOAs regardless of the dominance of the meaning to which the targets were related. These data can be accounted for by assuming multiple lexical entries for heterophonic homographs, single lexical entries for homophonic homographs, and phonological mediation of accessing meanings. Language-specific factors probably account for the long-lasting activation of subordinate meanings.

Attention↗

PubMed1992

Lexical mediation between sight and sound in speechreading.

In two experiments, we investigated whether simultaneous speech reading can influence the detection of speech in envelope-matched noise. Subjects attempted to detect the presence of a disyllabic utterance in noise while watching a speaker articulate a matching or a non-matching utterance. Speech detection was not facilitated by an audio-visual match, which suggests that listeners relied on low-level auditory cues whose perception was immune to cross-modal top-down influences. However, when the stimuli were words (Experiment 1), there was a (predicted) relative shift in bias, suggesting that the masking noise itself was perceived as more speechlike when its envelope corresponded to the visual information. This bias shift was absent, however, with non-word materials (Experiment 2). These results, which resemble earlier findings obtained with orthographic visual input, indicate that the mapping from sight to sound is lexically mediated even when, as in the case of the articulatory-phonetic correspondence, the cross-modal relationship is non-arbitrary.

Attention↗

PubMed1991

Phonetic recoding of print and its effect on the detection of concurrent speech in amplitude-modulated noise.

When an amplitude-modulated noise generated from a spoken word is presented simultaneously with the word's printed version, the noise sounds more speechlike. This auditory illusion obtained by Frost, Repp, and Katz (1988) suggests that subjects detect correspondences between speech amplitude envelopes and printed stimuli. The present study investigated whether the speech envelope is assembled from the printed word or whether it is lexically addressed. In two experiments subjects were presented with speech-plus-noise and with noise-only trials, and were required to detect the speech in the noise. The auditory stimuli were accompanied with matching or non-matching Hebrew print, which was unvoweled in Experiment 1 and voweled in Experiment 2. The stimuli of both experiments consisted of high-frequency words, low-frequency words, and non-words. The results demonstrated that matching print caused a strong bias to detect speech in the noise when the stimuli were either high- or low-frequency words, whereas no bias was found for non-words. The bias effect for words or non-words was not affected by spelling to sound regularity; that is, similar effects were obtained in the voweled and the unvoweled conditions. These results suggest that the amplitude envelope of the word is not assembled from the print. Rather, it is addressed directly from the printed word and retrieved from the mental lexicon. Since amplitude envelopes are contingent on detailed phonetic structures, this outcome suggests that representations of words in the mental lexicon are not only phonological but also phonetic in character.

Acoustic Stimulation↗

PubMed1991

Barium meal or endoscopy? A prospective randomized study of patient preference and physician decision making.

This study examines the preference of 64 out-patients for either a barium meal or an upper gastrointestinal endoscopy. The sequence of the examinations was randomized to avoid order bias. An initial preference for a barium meal of almost two-to-one, with 53% having no preference, was changed after the investigations to a preference for endoscopy of two-to-one with 5% having no preference. The use of mild sedation and the skill of the endoscopist had a major impact on the patients' opinion of the endoscopic procedure, and on their choice of examination for any repeat study. There was little agreement between clinical diagnosis and the result of investigation, but clinicians tended to accept the reported result of the investigation, especially if the result was abnormal. Despite a change in diagnosis in 34 of 49 patients there was little change in management as a result of the investigations, supporting the view that young patients with dyspepsia may be managed with symptomatic treatment initially, and without investigation. This study lends further support to the view that endoscopy should be the investigation of choice in patients with persistent dyspepsia, especially those whose age or infirmity may make barium examination suboptimal.

Barium Sulfate↗

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↗

PubMed1989

Endoscopic biliary therapy using the combined percutaneous and endoscopic technique.

Between September 1985 and December 1987, 74 patients underwent attempted endoscopic biliary therapy using a combined percutaneous transhepatic and endoscopic transpapillary approach (combined procedure). All patients had had failed endoscopy-alone procedures and had contraindications to surgery. The indication was palliation of malignant biliary obstruction in 66 cases (41 common bile duct, 25 hilar), assistance with sphincterotomy for the removal of common bile duct stones in 6 cases, and management of benign biliary stenosis in 2 cases. The initial procedure was percutaneous transhepatic access to the biliary tree, which was successful in all but 1 case (99%). The bile duct was drained externally for an average of 3.4 days before the combined procedure. One patient died during this period from hemorrhage associated with liver puncture. Combined procedure was performed in 72 cases and was successful in 60 [53 malignant stricture (53/66 = 80%), five common duct stone (5/6 = 83%), two benign stricture (2/2 = 100%)]. Procedure-related morbidity and mortality, respectively, were 12.5% and 0% for benign disease and 36% and 3% for malignant disease. The total (initial endoscopy included) morbidity and 30-day mortality were 33% and 0%, respectively, for benign disease and 62% and 27% for malignant disease. Subsequently, stent change has been required on 16 occasions, with endoscopy-only successful in 13 (81%) and repeat combined procedure being required in three (19%). The combined procedure improves the ability of endoscopy to offer nonsurgical therapy to poor risk patients with both malignant and benign biliary disease but is associated with significant morbidity and disease-related mortality.

Bile Duct Neoplasms↗

PubMed1989

Comparison of the geometric and the contrast models of similarity by presentation of visual stimuli to the left and the right visual fields.

In this study we investigated by means of the "same-different" decision task the process of comparing visual stimuli (schematic faces, familiar objects, houseplants, and nonsense figures) when presented for 100-150 msec to the right or to the left visual hemifields. The analysis of incorrect "same" responses showed that the addition of a common component (e.g., glasses, buttons) to a pair of nonidentical stimuli increased the percentage of incorrect same responses whereas the addition of the same component to one stimulus only in the pair decreased the percentage of incorrect "same" responses. This pattern, which is in accordance with Tversky's contrast model of similarity, is incompatible with any geometric model. Second, for schematic faces the results revealed that the left hemisphere is more sensitive to common than to distinctive features, whereas the right hemisphere is more sensitive to distinctive than to common features. No such interaction was obtained for the other type of stimuli. The implications of these results for models of similarity and the difference between the present findings and the findings of Sergent (1984) are discussed.

Adult↗