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Biomedical subjects

F Lille

Publications and source records attributed to F Lille.

At least 19 recordsLinked to original sources
PubMed1991

[Evoked potentials and age: different aging by sex?].

Brainstem Auditory Evoked Responses, Pattern-Shift Visual Evoked Potentials, and Short-latency Somatosensory Evoked Potentials for upper and lower limbs have been recorded in 60 male and female normal control subjects, aged 20-84 years. Age and gender effects were analyzed from the comparison of linear regressions with age and from the comparison of the mean values calculated in 3 age groups (20-40 years, 40-60 years, over 60 years). No noticeable effect of age was observed on Brainstem Auditory Evoked Responses. A gender-differential aging process is discussed for some of the short-latency Somatosensory Evoked Potentials. The constitution of reference norms which differ for male and female subjects is considered to be necessary.

Adult↗
PubMed1990

Sensory and cognitive event related potentials in workers chronically exposed to solvents.

To obtain objective measures of possible impairment due to organic solvents, auditory, visual and somatosensory evoked potentials and cognitive event related potentials were recorded in a group of 13 workers occupationally exposed to a mixture of various solvents. The patients were compared to healthy subjects and to chronic alcoholics seen during post-alcohol withdrawal. Auditory and visual evoked potentials were almost normal but somatosensory evoked potentials showed a slight decrease of peripheral conduction velocities and an increase of central conduction times more marked in the solvent exposed workers who were also alcoholics. The late "cognitive" components reflecting attention processes (N2 and P3) were normal. Solvent-exposed workers and alcoholics were both characterized by some difficulty in modulating their attentional resources according to task demands, as reflected by a tendency to responses (N1, N2 and P3) of similar amplitudes whether the stimulus was or was not the target. These findings support the presence, in solvent exposed workers, of minor dysfunction of the nervous system at both peripheral and cortical levels potentiated by alcohol as well as of mild cognitive impairments concerning attention processes.

Adult↗
PubMed1989

Heart rate and blood pressure reactivity during active coping with a mental task in healthy 18- to 73-year-old subjects.

Alterations with aging in the responses of heart rate (HR) and blood pressure (BP) reactivity were investigated during mild mental stress induced by undergoing a psychometric test, in 52 women and men aged 18-73 years, with no history of cardiovascular, renal or neurological deficits. HR and BP responses were measured before, during and after the test. Resting HR and diastolic BP (DBP) were not age-related while resting systolic BP (SBP) was. HR and SBP were increased during test performance. HR reactivity, measured during task execution as well as during recovery, was significantly decreased in older subjects. DBP recovery variation was lowered with age. These results indicate that age is an important determinant of the magnitude of cardiovascular adjustment during minor mental stress in women and men.

Adolescent↗
PubMed1988

Effects of lead and mercury intoxications on evoked potentials.

Pattern reversal, brain stem auditory and somatosensory evoked potentials (PREPs, BAEPs, SEPs) have been recorded on 13 patients occupationally exposed to inorganic lead compounds, in 9 patients occupationally or accidentally exposed to inorganic mercury compounds and in 26 chronic alcoholics. The results were compared to those of a normal control group. Peripheral conduction velocities were decreased in lead exposed workers and in alcoholics, but not modified in the mercury exposed patients. In the three exposed groups, an amplitude increase (PREPs and upper limb SEP cortical components), more important in the mercury group and an increase of central conduction time in case of lower limb stimulation, could be interpreted as early signs of nervous cortical impairment.

Adult↗
PubMed1984

Data entry on a computer terminal: repetitive work strains on the oculomotor and central nervous systems.

Continuous telemetric recordings including E.K.G., E.O.G., and E.E.G. were carried out on two subjects during 4 working days: 1 day of "reference work" or classical clerical activities, 3 days of "data entry work". Although the time allowed for the task was not limited, the performance assessed from oculomotor patterns remained stable throughout the day, from one day to the next and from one subject to another. This stability was reflected on the stereotyped E.E.G. patterns recorded during the work period, the differences occurring between reading and typing were more acute in the left cortical hemisphere than in the right. As a result of these stable patterns, the ultradian oscillations of the behavioural and physiological parameters were less during data entry than during work reference. The only possible time adjustments were the interruptions or breaks between two document pages and their variations could be considered as indicators of work load.

Adult↗
PubMed1983

[Shift work].

Explore the source record for details and available documents.

Accidents, Occupational↗
PubMed1983

Heart rate, urinary catecholamines and anxiety responses during mental stress in men in their fifties and seventies.

Alterations with ageing in the responses of heart rate (HR), urinary excretion of free epinephrine (E) and norepinephrine (NE) and anxiety were investigated during mild mental stress. Forty-eight normal male volunteers were studied: in control conditions; when subjected to psychometric tests; and during recovery. Men in their seventies had lower baseline levels of HR, E and NE than men in their fifties. Several anxiety indices were positively correlated with E. HR and NE were positively correlated. During stress, mean HR and E levels increased in the two age groups by the same percentages. Mean HR and E levels returned to pre-stress values more slowly in the older age group.

Age Factors↗
PubMed1983

Heart rate reactivity during minor mental stress in men in their 50s and 70s.

Modifications with aging in heart rate reactivity was investigated during minor mental stress. 27 normal male volunteers, aged 51-55 years (n = 10) and 71-74 years (n = 17), were studied in control conditions and while passing a series of 5 psychometric test measuring memory or intellectual speed. Men in their 70s had both lower heart rate baseline levels and lower reactivity during cognitive tasks.

Aged↗
PubMed1982

Variations in diurnal and nocturnal waking state in air traffic controllers.

Physiological variables of 22 air traffic controllers (ATCs), mean age 32, were continuously telemetrically recorded from 08:00 to 17:30 and on the following day from 19:00 to either 00:00 or 0.3:00. EEG (alpha and theta indices, slow delta waves), EOG (palpebral blinks), EMG (from the neck muscles) and EKG (HR) were recorded. Comparison between day and night shows an increase at night of HR and slow waves, particularly after midnight. These results were compared with similar ones obtained from two other populations of the same age having very different professional activities (university personnel and factory workers). The EEG indices and HR are higher in ATCs. The work load imposed by the need in air traffic control to maintain a high level of vigilance, especially difficult after midnight, is in great part responsible for the high values of physiological parameters observed in this study.

Adult↗
PubMed1982

[Electroencephalographic rhythms during psychometric tests at 50 and 70 years of age].

The experiments were conducted to investigate changes occurring between maturity and old age in variations of the EEG when performing a series of mental tasks. Forty three normal male volunteers, divided in two age groups separated by 2 decades (52.9 +/- 0.2 yr, N = 22; 72.2 +/- 0.2 yr, N = 21), were continuously recorded by telemetry in 3 conditions: control, tests, questionnaires. Beta, alpha and theta rhythms and the number of slow waves were measured after visual EEG interpretation. The study showed that: (1) theta rhythms and slow waves were in higher proportions in men in their 70s; (2) variations induced by the various mental tasks were very similar at ages 50 and 70; (3) the two groups differed mostly in theta rhythm responses during tests with a coding task; (4) test performances and EEG indices were correlated only in the older group for theta rhythms.

Aged↗
PubMed1981

Relationship between heart rate and sinus arrhythmia in air traffic controllers at work.

Sinus arrhythmia and mean heart rate were calculated from continuous electrocardiogram recordings of ten air traffic controllers. The telemetric recordings were carried out during 1 day of work and the following day's night shift. The individual variations of sinus arrhythmia were very large. The different situations (rest, relaxed work, intense work, eating, movements within the control room) had no specific effect on sinus arrhythmia. For each subject and for each group it was the value of the mean heart rate and its temporal variations that had the greatest influence on variations of sinus arrhythmia.

Adult↗
PubMed1980

[Health effects of night work].

Schedules of working times are related to various individual problems including the family, the quality of home and health problems. Only epidemiological studies can reveal the complexity of problems related to shift work. Night shifts ae increasing constantly and must be considered as a physiological, medical and social load of the worker.

Adult↗
PubMed1979

Effect of ageing and occupational activity on active wakefulness.

44 people were recorded by a telemetric system during 8 h of daily occupational activity. 24 were factory personnel (12: mean age 37 years, and 12: mean age 53 years) and 20 were univeristy researchers (10: mean age 39 years, and 10: mean age 53 years). Recordings were made concerning EEG, EOG, EMG, and EKG. At 35 years no differences were observed. At 50 years the organization of wakefulness was different for the two occupational activity groups. Although stable for the moment seemed to play a prominent role in the modulation of wakefulness.

Adult↗
PubMed1978

Spontaneous variations in level of arousal among aged individuals. Correlations with functional abilities and mental performances.

The aim of this study was to assess whether spontaneous interindividual variations in arousal level appreciated by telemetric recordings of physiological variables were related to mental performance and functional ability in institutionalized aged subjects. The sample studied was made up of 18 subjects (16 women and 2 men) aged 82-97, living in an old age home in Paris. Telemetric recordings of EEG, EKG, EMG and EOG were obtained over 8-hour periods, during the subjects' normal daily activity schedule. The Stockton Geriatric Rating Scale (SGRS), Benton's Visual Retention Test (VRT) and the Trail Making Test (TMT) were independently used to assess behaviour and mental performance of these aged persons. All correlations between telemetric data and psychological evaluations (the psychometric tests as well as the rating scale) were highly significant, even once the influence of the cultural level was controlled.

Activities of Daily Living↗
PubMed1975

Effects of time and tasks upon auditory and somatosensory evoked potentials in man.

Auditory evoked potentials (AEPs) recorded from the vertex and somatosensory evoked potentials (SEPs) recorded from the somatosensory and motor areas and vertex were examined during visual and auditory discrimination tasks, with and without motor responses, and during motor tasks alone in normal human subjects. These procedures allowed the separation of sensory discrimination from motor activity effects on the evoked potentials. It was observed that EPs were modified systematically by task and by temporal variables, even though vigilance, as evaluated through EEG recording and performance level, was stable throughout the experimental recording session. 1. AEPs were minimally influenced by time, but very sensitive to task. Inversely, the SEP amplitude decreased considerably with time and less with task. There was evidence of time/task interaction. 2. The magnitude of SEP attenuation in time was reduced by intervening rest periods. 3. The sensory modality in which the discrimination task was performed did not influence the effect on EPs. A discrimination task involving a motor response reduced EPs more than a pure discrimination or a pure motor task. The task effect seems to involve a general, mechanism (load imposed upon the subject) not dependent on the particular sensory channel used to deliver task-relevant information.

Auditory Cortex↗
PubMed1975

Effect of voluntary self-paced movements upon auditory and somatosensory evoked potentials in man.

The effect of voluntary self-paced movements upon auditory (AEPs) and somatosensory (SEPs) evoked potentials has been investigated according to the temporal relationship between movement and delivery of test stimuli. EPs were recorded in 7 subjects and averaged in 10 successive epochs extending from 880 msec before to 2500 msec after movement. AEPs were attenuated in all epochs. The decrease was greatest in the 220 msec epoch just following movement and involved components N85 and P170. SEPs were attenuated similarly to AEPs when movements were performed by the hand contralateral to somatosensory stimulation. Of the 5 SEP components, only P40 failed to reflect the attenuation, while P95 showed the greatest amplitude decrease. When stimulation was ipsilateral, SEP amplitude was attenuated only when close to the movement. N65 and P95 decreased while N130 increased. In all subjects the results were consistent for treatments of AEP and SEP (with contralateral movements), whereas large inter-individual differences were observed for the SEP with ipsilateral movements.

Auditory Cortex↗