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Laboratory Sessions (laboratory + session)
Selected AbstractsInfluences of Infant-Directed Speech on Early Word RecognitionINFANCY, Issue 6 2009Leher Singh When addressing infants, many adults adopt a particular type of speech, known as infant-directed speech (IDS). IDS is characterized by exaggerated intonation, as well as reduced speech rate, shorter utterance duration, and grammatical simplification. It is commonly asserted that IDS serves in part to facilitate language learning. Although intuitively appealing, direct empirical tests of this claim are surprisingly scarce. Additionally, studies that have examined associations between IDS and language learning have measured learning within a single laboratory session rather than the type of long-term storage of information necessary for word learning. In this study, 7- and 8-month-old infants' long-term memory for words was assessed when words were spoken in IDS and adult-directed speech (ADS). Word recognition over the long term was successful for words introduced in IDS, but not for those introduced in ADS, regardless of the register in which recognition stimuli were produced. Findings are discussed in the context of the influence of particular input styles on emergent word knowledge in prelexical infants. [source] Sex Differences in Salivary Cortisol Levels Following Naltrexone Administration,JOURNAL OF APPLIED BIOBEHAVIORAL RESEARCH, Issue 2 2000Laura Cousino Klein Effects of endogenous opioid peptide blockade by naltrexone on salivary Cortisol levels were examined in healthy men (n= 8) and women (n= 6). Participants received naltrexone (100 mg) during one laboratory session and a placebo pill during another session. Drug order was counterbalanced across participants. Saliva samples were collected 24 hr after each pill was administered. Among women, salivary Cortisol levels significantly increased following naltrexone administration compared with a placebo pill. Naltrexone administration did not alter salivary Cortisol levels in men. Results suggest sex differences in neuroendocrine sensitivity to opioid blockade, a finding that may hold significance with regard to the treatment of alcohol addiction with naltrexone. [source] Reduced Labial Temperature in Response to Sexual Films with Distractors among Women with Lower Sexual DesireTHE JOURNAL OF SEXUAL MEDICINE, Issue 2pt2 2010Nicole Prause PhD ABSTRACT Introduction., Sexual desire variation traditionally has been treated as due to variance in affective response to sexual stimulation, but differences in attention to the stimuli may better account for differences in sexual desire. Aim., Determine whether sexual desire varies due to attention biases towards sexual stimuli. Main outcome measures., Sexual arousal was quantified by physiological (labia minus temperature) and experienced (continuously adjusting a potentiometer) indicators. Methods., Twenty-two women who varied in their level of sexual desire attended one laboratory session during which they viewed a neutral nature film, a sexual film, and a sexual film with distractors while their labial temperature and self-reported sexual arousal were recorded. Results., Participants reported and displayed lower sexual arousal during the sexual stimulus with distractors as compared to the sexual film without distractors. While all women reported lower sexual arousal to the sexual film with distractors, women with relatively lower sexual desire also reported lower sexual arousal to the sexual film with no distractors than women with higher sexual desire. Physiologically, women with lower sexual desire exhibited lower labial temperature. Conclusions., Since the predicted lower self-reported and physiological sexual arousal to the sexual stimulus with distractors for the women with lower sexual desire did not emerge, this study does not support that sexual desire levels vary due to differential attention to sexual stimuli. Prause N, and Heiman J. Reduced labial temperature in response to sexual films with distractors among women with lower sexual desire. J Sex Med 2010;7:951,963. [source] Isolation of Caenorhabditis elegans genomic DNA and detection of deletions in the unc-93 gene using PCRBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 3 2005James L. Lissemore Abstract PCR, genomic DNA isolation, and agarose gel electrophoresis are common molecular biology techniques with a wide range of applications. Therefore, we have developed a series of exercises employing these techniques for an intermediate level undergraduate molecular biology laboratory course. In these exercises, students isolate genomic DNA from the nematode Caenorhabditis elegans and use PCR to detect deletions in the C. elegans unc-93 gene. In advance of the exercises, wild-type and three different unc-93 deletion mutant strains are grown, harvested, and frozen by the instructor. In one approach, students isolate genomic DNA from each strain using a genomic DNA isolation kit and use agarose gel electrophoresis to analyze the DNA and to estimate its concentration. PCRs using primers directed to two different regions of the unc-93 gene are carried out on the genomic DNA from wild-type and mutant strains, and the PCR products are analyzed by agarose gel electrophoresis. Students analyze the gel to determine the approximate location and size of deletions in the three mutant strains. Alternatively, students may lyse single nematodes and carry out PCR in one laboratory session. These exercises should be easily adaptable to detection of well characterized deletions in any organism. [source] Abuse liability of intravenous buprenorphine/naloxone and buprenorphine alone in buprenorphine-maintained intravenous heroin abusersADDICTION, Issue 4 2010Sandra D. Comer ABSTRACT Background Sublingual buprenorphine is an effective maintenance treatment for opioid dependence, yet intravenous buprenorphine misuse occurs. A buprenorphine/naloxone formulation was developed to mitigate this misuse risk. This randomized, double-blind, cross-over study was conducted to assess the intravenous abuse potential of buprenorphine/naloxone compared with buprenorphine in buprenorphine-maintained injection drug users (IDUs). Methods Intravenous heroin users (n = 12) lived in the hospital for 8,9 weeks and were maintained on each of three different sublingual buprenorphine doses (2 mg, 8 mg, 24 mg). Under each maintenance dose, participants completed laboratory sessions during which the reinforcing and subjective effects of intravenous placebo, naloxone, heroin and low and high doses of buprenorphine and buprenorphine/naloxone were examined. Every participant received each test dose under the three buprenorphine maintenance dose conditions. Results Intravenous buprenorphine/naloxone was self-administered less frequently than buprenorphine or heroin (P < 0.0005). Participants were most likely to self-administer drug intravenously when maintained on the lowest sublingual buprenorphine dose. Subjective ratings of ,drug liking' and ,desire to take the drug again' were lower for buprenorphine/naloxone than for buprenorphine or heroin (P = 0.0001). Participants reported that they would pay significantly less money for buprenorphine/naloxone than for buprenorphine or heroin (P < 0.05). Seven adverse events were reported; most were mild and transient. Conclusions These data suggest that although the buprenorphine/naloxone combination has intravenous abuse potential, that potential is lower than it is for buprenorphine alone, particularly when participants received higher maintenance doses and lower buprenorphine/naloxone challenge doses. Buprenorphine/naloxone may be a reasonable option for managing the risk for buprenorphine misuse during opioid dependence treatment. [source] Effects of Stress and Alcohol on Subjective State in HumansALCOHOLISM, Issue 6 2002Anna H. V. Söderpalm Background: There is increasing evidence that stress and hypothalamic-pituitary-adrenal axis activation interact with drugs of abuse and influence drug-taking behaviors. Both studies with laboratory animals and survey data with alcohol users suggest that acute or chronic stressful events increase alcohol intake. One mechanism for the increase in alcohol intake may be that stress alters the subjective effects produced by the drug in ways that enhance the reinforcing properties of alcohol. Therefore, in this study we determined whether an acute social stressor alters subjective responses to ethanol in humans. The stressor was a modified version of the Trier Social Stress Test, an arithmetic task that increases cortisol levels. Methods: Twenty male volunteers participated in two laboratory sessions, in which they performed the Trier Social Stress Test on one session and no task on the other session, immediately before consuming a beverage that contained ethanol (0.8 g/kg in juice) or placebo (juice alone). Eleven subjects received ethanol on both sessions, and nine subjects received placebo on both sessions. Primary dependent measures were self-report questionnaires of mood states. Salivary levels of cortisol were obtained to confirm the effectiveness of the stress procedure. Results: Stress alone produced stimulant-like subjective effects. In the group who received ethanol, stress increased sedative-like effects and decreased stimulant-like effects. Conclusions: At this relatively high dose of ethanol, stress increased sedative effects of alcohol and did not increase desire for more alcohol. It is possible that in some individuals, the increased sedative effects after stress may increase the likelihood of consuming more alcohol. The effects of stress on consumption at this, or lower, doses of alcohol remain to be determined. [source] ALDH2 Status, Alcohol Expectancies, and Alcohol Response: Preliminary Evidence for a Mediation ModelALCOHOLISM, Issue 11 2001Denis M. McCarthy Background: A genetic variant in the alcohol-metabolizing enzyme (aldehyde dehydrogenase;ALDH2*2 allele), common in individuals of Asian heritage, has been associated with both physiologic response to alcohol and alcohol consumption. Prior research has also demonstrated that those with ALDH2*2 alleles have lower positive alcohol expectancies than those without these alleles. This preliminary study was designed to test whether the level of response to alcohol is the mechanism by which ALDH2 status may affect alcohol expectancies. Methods: Data were collected from 32 Asian American college students (14 women and 18 men). By use of a randomized, double-blind design, participants were administered oral placebo and alcohol at separate laboratory sessions. Data included blood tests to establish ALDH2 status, questionnaire measures of demographic information and alcohol expectancy, and several physiologic measures collected after placebo and alcohol administration. Results: ALDH2 status was related to alcohol response measures for both men and women. ALDH2 status was also related to tension reduction expectancies for women and to expectancies for cognitive behavioral impairment for men. In the male sample, the ALDH2/expectancy relationship was fully explained by the level of response to alcohol. Conclusions: These results represent a first step in understanding the mechanisms by which genetic factors, such as ALDH2 status, can affect alcohol-related learning. [source] IMPLICATIONS OF ALTERNATIVE EMISSION TRADING PLANS: EXPERIMENTAL EVIDENCEPACIFIC ECONOMIC REVIEW, Issue 2 2006Neil J. Buckley Theory suggests the long-run equilibria of the plans will differ with baselines proportional to output. To test this prediction we develop a computerized environment in which subjects representing firms can adjust their emission rates and capacity levels and trade emission rights in a sealed-bid auction. Demand for output is simulated. We report on six laboratory sessions with variable emissions rates, but fixed capacity: three each with the cap-and-trade and baseline-and-credit mechanisms. [source] Increases in core body temperature precede hot flashes in a prostate cancer patientPSYCHO-ONCOLOGY, Issue 5 2009Laura J. Hanisch Abstract Objective: An effective and safe alternative treatment to hormone replacement therapy for hot flashes is needed for cancer patients. Interventions targeting the triggering mechanisms of hot flashes hold promise. Increases in core body temperature are a precursor of most hot flashes in women, and similar findings in prostate cancer patients undergoing androgen deprivation therapy would support further research in this area. We present preliminary findings of physiological changes in a prostate cancer patient with frequent hot flashes. Methods: Physiological changes in sternal skin conductance, heart rate, and core body temperature were continuously measured during two 3.5,h laboratory sessions. Perceived characteristics of hot flashes were recorded in a diary. Results: Five hot flashes were reported during laboratory sessions. Severity and bother ratings were low. All hot flashes were accompanied by large increases in sternal skin conductance and moderate increases in heart rate. Core body temperature increased 0.11,0.32°C prior to and fell 0.23,0.44°C following the peak increase in skin conductance. Conclusions: This case study suggests that hot flashes in men may be preceded by increases in core body temperature. Identification of behavioral factors that raise core body temperature may lead to specific treatment strategies to reduce the frequency of hot flashes. Copyright © 2008 John Wiley & Sons, Ltd. [source] Variability of sleep parameters across multiple laboratory sessions in healthy young subjects: The "very first night effect"PSYCHOPHYSIOLOGY, Issue 4 2002José-Luis Lorenzo Many studies have been carried out to assess the variability of sleep parameters. The first night effect is one of the most important factors in this variability and has been extensively studied. However, the readaptation phenomenon when subjects returned to the sleep laboratory after spending a certain period of time at home has been not systematically evaluated. To investigate this phenomenon across multiple sleep laboratory sessions, polysomnographic data from 12 healthy young subjects for 12 nights (three periods each of 4 consecutive nights, with a minimum of 1 month between them) were collected. The first night effect was present only in the first night of the first period ("very first night") and was significant only for REM sleep-related variables. We conclude that the results from the first nights of consecutive periods within a specific protocol with healthy young subjects need not be discarded in subsequent analyses. [source] | |||||||||||||