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Biomedical subjects

L W Thompson

Publications and source records attributed to L W Thompson.

At least 55 records · Page 3Linked to original sources
PubMed1984

Effects of bereavement on self-perceptions of physical health in elderly widows and widowers.

Multiple indices of self-perceived physical health for 212 older widows and widowers, 2 months following the loss of their spouse, were contrasted with the responses of 162 comparison control participants for a comparable period. Although physician visits and hospitalizations were reported to be no more frequent among the bereaved, they did report significantly more recently developed or worsened illnesses, greater use of medications, and poorer health ratings in general. These differences were independent of sex and variation in socioeconomic background. Significant sex differences, although minimal, indicated poorer perceived health among women.

Aged↗
PubMed1983

Presentation of a flashing light following training produces amnesia.

Long-Evans rats given exposure to a flashing-light stimulus following one-trial fear conditioning showed amnesia relative to controls not given the flashing-light experience. Together with previous results obtained in this laboratory, it is apparent that the flashing light modulates memory processing.

Animals↗
PubMed1983

Effects of bereavement on indicators of mental health in elderly widows and widowers.

The effects of bereavement on self-report measures of psychological distress were evaluated in widows and widowers at approximately 2 months after the death of a spouse. These data represent the first time of measurement in an ongoing longitudinal study of conjugal bereavement in elders. Responses of 95 male and 104 female elderly bereaved on measures of grief, depression, global severity of psychological distress, and general mental health functioning were compared with those of 79 male and female elderly individuals who were not currently suffering from the loss of a spouse. In general, means for the bereaved group were not in ranges consistent with the presence of serious psychopathology. Women in both groups reported greater distress than men, and significant sex-by-bereavement-status interactions on mental health measures were not observed.

Aged↗
PubMed1983

Effectiveness of psychotherapy for both endogenous and nonendogenous depression in older adult outpatients.

This study explored the effectiveness of brief psychotherapies for treatment of elderly depressed outpatients. All were in a current episode of major depressive disorder, but half the sample (n = 15) presented with endogenous symptomatology as well. Patients were assigned to either behavioral, cognitive, or insight-oriented psychotherapy for 16 sessions over a 12-week period. Evaluation occurred before and after therapy, and at four times during a 1-year follow-up interval. Nonendogenous patients responded more favorably to psychotherapy; this differential effect persisted throughout follow-up. Significant improvement, however, was made by some endogenous patients. One-third were not depressed by termination of therapy, and seven others were notably improved. Eight of 15 had not relapsed at 1-year follow-up.

Aged↗
PubMed1983

Acquisitive evolution of ribitol dehydrogenase in Klebsiella pneumoniae.

Selection in continuous culture of Klebsiella pneumoniae mutants that have gained the ability to utilize xylitol while also retaining regulatory control over ribitol utilization was achieved with a dual-substrate regime. Initial steady-state cultures of wild-type organisms were maintained with 0.005% (0.329 mM) ribitol. Mutants of various types proliferated when the composition of the limiting medium was changed to 0.005% ribitol plus 0.250% (16.43 mM) xylitol.

Culture Media↗
PubMed1982

A comparison of the emitted late positive potential in older and young adults.

An emitted potential paradigm was used to investigate P3 scalp potentials in a group of older individuals (M = 66.8 years) and a group of younger persons (M = 22.0 years). Since no physical stimulus is necessary to elicit an emitted potential, an age comparison of P3 can be made which does not depend on normal sensory transmission channels. Both traditional and latency corrected averages to missing auditory clicks were analyzed from electrodes placed over midline frontal, central, and parietal locations. Results indicated that while the scalp distribution of emitted potentials was similar for both age groups, amplitudes at Pz and Cz were significantly smaller in the older group. Latency corrected potentials indicated similar trends but did not reach significant levels. No group differences were seen for N2 or P3 latencies for either traditional or corrected averages. The findings support age differences in the amplitudes of the P3 component and suggest that when P3 is not synchronized with a sensory event, latencies in this component may not be sensitive to age differences.

Adult↗
PubMed1981

Age and sex differences in the human auditory brainstem response.

Age and sex differences in the brainstem auditory evoked response (BAER) were investigated in older (60 to 79 yrs), middle-aged (40 to 59 years), and young (20 to 39 yrs) individuals. Within each age group the number of males (N = 10) and females (N = 10) were divided equally. Scalp potentials were recorded from the vertex to clicks presented at 60, 70, and 80 dB(SL) for stimulus rates of 5, 10, and 15 clicks/sec. Results indicated that older adults had longer latencies at Wave III than either middle-aged or young adults. Age effects were also found for Waves I, II, and IV but were restricted to the lowest intensity and were more evident in older males than females. Significant sex effects showed that the females in each group had shorter Wave IV and V latencies than males. The results suggest that age affects neural propagation at the level of the olivary complex (Wave III) and that BAER latencies are also influenced by the sex of the individual.

Adult↗
PubMed1980

Sex differences in the amplitudes and latencies of the human auditory brain stem potential.

Sex differences in the amplitudes and latencies of the auditory brain stem potential (BAEP) were investigated using 3 levels of intensity and 3 stimulus presentation rates. The females displayed consistently larger BAEPs for waves IV, V, VI, VII than the males. The only latency differences which reached significance over all the intensities and rates occurred for wave V. The females showed significantly shorter wave V latencies than the males. Since hearing losses and individually determined click thresholds were comparable between the two groups tested, the exact sources of the uneven distribution of amplitude and latency effects are in question. Differences in the relative distances of the anatomical generators are considered in accounting for the sex differences. Because the precise origin of the sex differences cannot be stated with certainty at this time, attempts to develop normative data for the BAEP should consider the possible influences of sex differences.

Adult↗
PubMed1980

Auditory averaged evoked potentials and aging: factors of stimulus, task and topography.

The averaged evoked potential to brief tones was compared for 10 young and 10 elderly female subjects. The amplitudes of the sensory components (P1, N1 and P2) were not affected by an infrequent change in pitch of the tones or instructing subjects to count or ignore them; but overall the elderly had a larger P1 and smaller P2 amplitude and a difference in the scalp distribution of P2. Repetition of the tones produced a decrement in these sensory components and a differential one for young and old subjects A slow potential complex consisting of components N2, P3 and SW appeared to changes in tone pitch and became more pronounced when attention was directed to the tones. Overall smaller SPs for oder subjects were interpreted as evidence for a change with age in the cortical representation of the orienting response. Topographical analysis of SPs indicated diminished activity in frontal (Fz) electrodes for elderly persons, suggestive of an enhanced aging process in the frontal cortices.

Adult↗
PubMed1980

Age differences in the contingent negative variation (CNV): reduced frontal activity in the elderly.

The effects of distraction on the contingent negative variation (CNV) were investigated in a group of 11 elderly (mean = 72.2 years) and a group of 12 young (mean = 23.3 years) subjects. Scalp electrical activity was recorded from midline sites at frontal, central, and parietal locations. Three experimental conditions included Recall, No Recall, and Control situations. In the Recall, or distraction condition, spoken consonant-vowel-consonant (CVC) letters were presented concurrently with the CNV signal interval and were recalled by the subjects after each trial. The No Recall condition was similar to the Recall task except that subjects were not required to repeat the CVSs. The Control condition presented a standard S1 - S2 CNV situation without CVCs. Amplitudes of the CNV, reaction times (RTs), and heart rate (HR) served as indices of distraction. The effects of distraction for both age groups indicated reduced CNVs, lengthened RTs, and elevated HRs. However, a significant age by electrode interaction revealed that while CNV amplitudes at central and parietal sites were comparable between age groups, amplitudes at the frontal placement were consistently reduced in the elderly compared to the young in all conditions. The finding of diminished frontal activity, as measured by the CNV, suggests a process of selective cortical aging and possible cellular loss which may be linked to performance deficits.

Adult↗