Aging on the input versus output side: Theoretical implications of age-linked asymmetries between detecting versus retrieving orthographic information.

This experiment tested for age-linked asymmetries predicted under Node Structure theory (NST; D.G. MacKay & D. M. Burke, 1990) between detecting versus retrieving orthographic information. Older adults detected that briefly presented words were correctly spelled (e.g., endeavor) or misspelled (e.g., endeavuor) as readily as did young adults. However, they were less able than young adults to retrieve the correctly and incorrectly spelled words that they had seen. These age-linked asymmetries were not due to educational factors, stimulus characteristics, sensory-level factors, task complexity, floor or ceiling effects, general slowing, or cohort-related activities, but they were consistent with NST predictions and with similar asymmetries in a wide range of other studies. By contrast, repetition deficits in detecting and retrieving repeated- versus unrepeated-letter misspellings (e.g., elderdly vs. elderkly) were symmetrical or equivalent in magnitude for young and older adults. Implications for a wide range of theories of cognitive aging and of repetition deficits are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Age-linked declines in retrieving orthographic knowledge: Empirical, practical, and theoretical implications": Correction to MacKay and Abrams (1998).

Reports an error in "Age-linked declines in retrieving orthographic knowledge: Empirical, practical, and theoretical implications" by Donald G. MacKay and Lise Abrams (Psychology and Aging, 1998[Dec], Vol 13[4], 647-662). The article contained an error. In Table 1 on page 652, the values for rated spelling ability at age 20 and at current age were reversed for older and oldest adults. The corrected table is included in the erratum, with values that have been changed in bold. (The following abstract of the original article appeared in record 1998-11674-011.) This study developed and tested a Transmission Deficit hypothesis of how aging affects retrieval of orthographic knowledge. Young, older, and very old adults heard a tape-recorded series of difficult-to-spell words of high and low frequency, spoken slowly, clearly and repeatedly, and wrote down each word at their own pace. With perceptual errors and vocabulary differences factored out, misspellings increased with aging, especially for high-frequency words. In addition, data from a metamemory questionnaire indicated that the oldest adults were aware of their declining ability to spell. These findings were not due to general slowing, educational factors, hours per week spent reading, writing, or solving crossword puzzles, or age-linked declines in monitoring or detecting self-produced errors. However, the results fit Transmission Deficit predictions, and suggested an age-linked decline in retrieval of orthographic knowledge that resembles age-linked declines in spoken word retrieval observed in many other studies. Practical implications of this age-linked decline for conceptions of normal aging are noted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speed and accuracy of saccadic eye movements: Characteristics of impulse variability in the oculomotor system.

Dynamic characteristics observed in the trajectories of saccadic eye movements revealed systematic variability of the force pulses used to move the eyes. This variability causes saccades to exhibit a linear speed–accuracy trade-off: As the average distance and duration of saccades toward specified target points increase, the standard deviations of saccadic-movement endpoints increase linearly with the saccades' average velocity. The linear trade-off, and other observed stochastic properties of saccades, may be attributed to noise in neuromotor processes and may be described in terms of an impulse-variability model originally designed for characterizing limb movements. According to the model, both eye and limb movements are controlled through stochastic force and time parameters that govern movement kinematics. Such an account may promote a unified conceptual framework for understanding a wide range of motor behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-administration of alcohol before and after a public speaking challenge by individuals with social phobia.

[Correction Notice: An erratum for this article was reported in Vol 16(3) of Psychology of Addictive Behaviors (see record 2009-17717-001). On page 121, in the abstract, the penultimate sentence incorrectly reads, “As predicted, participants consumed more alcohol following the anxiety challenge than following the control task; however, the opposite pattern was evidenced for drinking following the 2 activities.” The sentence should read as follows: “As predicted, participants consumed more alcohol following the anxiety challenge than following the control task; however, the opposite pattern was evidenced for drinking preceding the 2 activities.”] K. Abrams, M. Kushner, K. Medina, and A. Voight (2001) showed that alcohol attenuates social anxiety symptoms in socially phobic individuals. This article examines whether social anxiety symptoms can lead to increased alcohol use in this same population. Forty-four individuals with social phobia attended 2 laboratory sessions, spaced 1 week apart, in groups of approximately 10. Participants underwent a social anxiety challenge during 1 session and a control task during the other. Half of the sample self-administered alcohol immediately before, and half immediately after, these 2 activities. As predicted, participants consumed more alcohol following the anxiety challenge than following the control task; however, the opposite pattern was evidenced for drinking following the 2 activities. These findings add to an understanding of why social phobia and alcohol problems tend to co-occur. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Redundancy resolution of the human arm and an upper limb exoskeleton

The human arm has 7 degrees of freedom (DOF) while only 6 DOF are required to position the wrist and orient the palm. Thus, the inverse kinematics of an human arm has a nonunique solution. Resolving this redundancy becomes critical as the human interacts with a wearable robot and the inverse kinematics solution of these two coupled systems must be identical to guarantee an seamless integration. The redundancy of the arm can be formulated by defining the swivel angle, the rotation angle of the plane defined by the upper and lower arm around a virtual axis that connects the shoulder and wrist joints. Analyzing reaching tasks recorded with a motion capture system indicates that the swivel angle is selected such that when the elbow joint is flexed, the palm points to the head. Based on these experimental results, a new criterion is formed to resolve the human arm redundancy. This criterion was implemented into the control algorithm of an upper limb 7-DOF wearable robot. Experimental results indicate that by using the proposed redundancy resolution criterion, the error between the predicted and the actual swivel angle adopted by the motor control system is less then 5°.     

Ruminal in vitro degradability of protein in alfalfa harvested as standing forage or baled hay.

Eighty-nine samples, 45 of standing forage and 44 of baled hay, were collected from alfalfa harvested at various maturities over three cuttings each during 2 yr. Alfalfa was cut and conditioned mechanically; samples of standing forage were collected by removing bunches of forage from windrows and freeze-drying them. Forage was allowed to field cure and was harvested at an average 80% DM as small rectangular bales; samples of baled hay were collected by coring bales after storing for 3 to 6 mo. Samples were analyzed for DM, ADF, total N, fractions of total N present as ADIN, N degraded at 0 h, and potentially degradable protein N. Ruminal protein degradation rates and escapes were estimated using an inhibitor in vitro system, assuming that ADIN was unavailable and that ruminal passage rate was .06/h. Standing forage contained smaller fractions of ADIN and N degraded at 0 h, contained a larger fraction of potentially degradable N, and had more rapid degradation rates and lower estimated protein escapes than baled hay. Mean degradation rates and estimated escapes were .171/h and 24% for standing forage and .075/h and 40% for baled hay. There were no differences in degradation rate or estimated escape because of harvest year, and neither was significantly related to maturity or to ADF concentration. Results indicate a significant advantage in ruminal protein escape, compared with grazed alfalfa, for alfalfa harvested and stored as hay.     

Symptoms of depression and survival experience among three samples of smokers trying to quit.

Symptoms of depression have been associated with increased smoking prevalence and failure to quit smoking in several cross-sectional and population-based studies. Few studies, however, have prospectively examined the ability of current symptoms of depression to predict failure to quit smoking in treatment-motivated smokers. Pretreatment depressed mood was assessed by 3 different methods in 3 separate samples, 2 of which comprised smokers receiving combined pharmacological and behavioral treatments and a 3rd in which smokers received self-help materials only. In all studies, time in days from quit day until the 1st cigarette was ascertained to document survival. Survival analyses showed that in all 3 studies survival time was significantly and negatively related to measures of even very low levels of pretreatment depressed mood. Results were replicated across 3 independent samples and were robust and uniformly clear, indicating that low levels of depressive symptoms assessed at baseline predict time to 1st cigarette smoked after attempted quitting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of hypertonic saline solutions and dextran in dialysis-induced hypotension

The efficacy of three hypertonic saline solutions for treating dialysis-induced hypotension in a randomized, blinded, crossover clinical trial of 10 patients (a minimum of three cycles per solution) was compared. Dialysis-induced hypotension, defined as a decrease in systolic blood pressure of at least 10 mm Hg or systolic blood pressure less than 100 mm Hg, was treated with an iv bolus of either 10 mL of 23% saturated hypertonic saline, 30 mL of 7.5% hypertonic saline, or 30 mL of 7.5% saline with 6% dextran 70, each containing similar osmolar loads of 80, 80, and 100 mosM, respectively. All three solutions raised systolic blood pressure within 5 min (mean pretreatment systolic blood pressure, 87 mm Hg; mean posttreatment systolic blood pressure, 101 mm Hg; P < 0.05). The magnitude of the increase was greater with saturated hypertonic saline (15 mm Hg) and dextran 70 (17 mm Hg) compared with that with hypertonic saline (9 mm Hg; P < 0.05). At 10 min, dialysis-induced hypotension was less frequent with saturated hypertonic saline (incidence, 9%) compared with hypertonic saline (45%). Beyond 10 min, however, there was a trend toward a lower incidence of further dialysis-induced hypotension with dextran 70. There were no side effects. Given equal osmole loads, the more concentrated solution produced a greater increase in systolic blood pressure. The addition of an oncotic agent such as dextran may prolong the blood pressure response beyond 10 min. It was concluded that hypertonic saline solutions safely and effectively treat dialysis-induced hypotension.     

A Tourette-like syndrome following cardiopulmonary bypass and hypothermia: MRI volumetric measurements

OBJECTIVES: To review the outcome of men with Stage I nonseminomatous germ cell tumors managed with a policy of active surveillance following orchiectomy. METHODS: The clinical records of all men with Stage I nonseminomatous germ cell tumors seen at Royal Prince Alfred Hospital, Australia between 1982 and 1995 were reviewed. Data were obtained concerning the histologic type of tumor, levels of serum tumor markers, relapse and subsequent treatment, and survival. RESULTS: Seventy-seven patients were entered into the active surveillance protocol between 1982 and 1995. With a minimum follow-up of 2 years, 27 (35%) have relapsed, with a median time to relapse of 5 months. Two late relapses occurred at 37 and 57 months after diagnosis. Relapses occurred most commonly in the retroperitoneal lymph nodes, with the lungs the second most common site. Following treatment with chemotherapy and surgery, all patients achieved complete remission, with 1 patient subsequently relapsing and ultimately dying of progressive tumor. One other patient died of acute myeloid leukemia, thought to be secondary to chemotherapy. Overall, 75 patients (97%) remain alive and free of disease. CONCLUSIONS: Active surveillance is a safe and effective approach to the management of Stage I nonseminomatous germ cell tumors. Although most relapses occur within the first 2 years, late relapses may occur.