Biomedical subjects

P J Houx

Publications and source records attributed to P J Houx.

At least 19 recordsLinked to original sources

PubMed2005

Positive affect and its relationship to free recall memory performance in a sample of older Dutch adults from the Maastricht Aging Study.

OBJECTIVE: A Dutch translation of the Positive and Negative Affect Scale (PANAS) was used to measure Positive Affect (PA) and its relationship to episodic memory in a sample of Dutch adults between the ages of 40 to 82 years. Specifically, the role of PA was examined as a predictor of performance on a serial list learning task that included a recognition and free recall component. METHODS: Participants were divided into two age groupings representing middle-age (40 to 64 years) and older (65 to 82 years) adults with respect to the study sample. RESULTS: PA was not related to recognition performance in either age grouping. In the older age group, however, PA predicted free recall. CONCLUSIONS: PA facilitated episodic memory in older adults when unsupported tasks conditions were present that placed heavy demands on processing resources.

Adult↗

PubMed2002

Predictors of attrition in a longitudinal cognitive aging study: the Maastricht Aging Study (MAAS).

A large sample of older participants of the Maastricht Aging Study (MAAS) were compared to drop-outs at the 3-year follow-up with respect to socio-demographic, health, and cognitive characteristics. In addition, the impact of selective drop-out on measures of cognitive change was examined. To this end, hypothetical scores were estimated for drop-outs by using single and multiple imputation methods. Of the initial sample of 539 subjects, aged 49 years and older at baseline, 116 (22 %) did not return for the follow-up (n = 32 had died, n = 84 refused participation). Drop-outs who refused to participate in the follow-up were more often women, had lower educational levels, and had lower baseline scores on neurocognitive tests. Follow-up drop-outs who had died were more often men, older, and had a poorer performance on cognitive tests than the follow-up participants. Although follow-up participants and drop-outs differed in terms of socio-demographic and cognitive characteristics, attrition appeared to have little effect on the estimates of cognitive change.

Aged↗

PubMed2002

Testing cognitive function in elderly populations: the PROSPER study. PROspective Study of Pravastatin in the Elderly at Risk.

OBJECTIVES: For large scale follow up studies with non-demented patients in which cognition is an endpoint, there is a need for short, inexpensive, sensitive, and reliable neuropsychological tests that are suitable for repeated measurements. The commonly used Mini-Mental-State-Examination fulfils only the first two requirements. METHODS: In the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), 5804 elderly subjects aged 70 to 82 years were examined using a learning test (memory), a coding test (general speed), and a short version of the Stroop test (attention). Data presented here were collected at dual baseline, before randomisation for active treatment. RESULTS: The tests proved to be reliable (with test/retest reliabilities ranging from acceptable (r=0.63) to high (r=0.88) and sensitive to detect small differences in subjects from different age categories. All tests showed significant practice effects: performance increased from the first measurement to the first follow up after two weeks. CONCLUSION: Normative data are provided that can be used for one time neuropsychological testing as well as for assessing individual and group change. Methods for analysing cognitive change are proposed.

Aged↗

PubMed2000

Pesticide exposure and risk of mild cognitive dysfunction.

Little is known about the adverse effects of substances, such as pesticides and metals, on the development of mild cognitive dysfunction (MCD). Cross-sectional and prospective data from the Maastricht Aging Study were used to find out the potential neurotoxicity of particular substances. Exposure to pesticides, for example by arable farmers and gardeners, was associated with increased risks of MCD. Exposure to metals and organic solvents was not associated with MCD. Our findings might reflect subtle changes in brain function among people exposed to pesticides.

Aged↗

PubMed2000

Does migraine headache affect cognitive function in the elderly? Report from the Maastricht Aging Study (MAAS).

The aim of this study was to examine two aspects of cognitive functioning-information processing speed and memory-in both young/middle-aged and older subjects with and without migraine, using data from a large population-based sample. We found that, although age had a large effect on processing speed and memory, migraine did not influence cognitive performance. In addition, there was no significant interaction between age and migraine on processing speed and memory. Our results suggest that, in the general population, migraine does not seriously affect cognitive functioning in young/middle-aged or older adults.

Adult↗

PubMed2000

Mild hearing impairment can reduce verbal memory performance in a healthy adult population.

We studied to what extent immediate and delayed recall in an auditory verbal learning paradigm was affected by basic information processing speed (digit copying) and hearing acuity (average hearing acuity at 1, 2 and 4 KHz at the better ear). A group of 453 individuals in the age between 23 and 82 years with no overt hearing pathology was recruited from a larger study of cognitive aging (Maastricht Aging Study, MAAS). After controlling for age, sex, educational level, and processing speed it was found that a mild to moderate hearing loss predicted lower verbal memory performance. Auditory administered verbal memory tests can underestimate true memory performance, particularly in older individuals with unknown hearing status.

Adult↗

PubMed1999

Cognition after major surgery in the elderly: test performance and complaints.

There is evidence that older people in particular have a higher risk of cognitive dysfunction after surgery under general anaesthesia. We have investigated the severity and character of postoperative cognitive dysfunction after major non-cardiac surgery in patients older than 65 yr. Also, cognitive complaints were studied. Cognitive function was assessed using cognitive tests measuring memory and attention, such as ability to shift between two sequences, ability to ward off distractions, simple cognitive speed and speed of general information processing. These tests were performed before, 1 week (short-term) and 3 months (long-term) after surgery. Cognitive performance of the patients was compared with that of healthy subjects not undergoing surgery who were also subjected to repeated cognitive measurements. After 1 week, patients had a poorer performance on tests measuring simple cognitive speed and speed of general information processing. Three months after surgery, patients and controls showed improved cognitive performance compared with the first measurement. These results suggest that major non-cardiac surgery in older patients causes short-term but not long-term cognitive dysfunction. However, after 6 months, 14 of 48 patients (29%) reported having experienced a decline in cognitive abilities after discharge from hospital. Eight of these 14 patients (17%) were still experiencing these cognitive complaints and reported 'not being the same since the operation'. These findings emphasize that cognitive complaints after major surgery may not reflect actual changes in cognitive performance but may be caused by other factors such as depression or awareness of age-related changes.

Aged↗

PubMed1998

Effects of age on performance in a finger-precuing task.

This study investigated age-related precuing effects in the finger-precuing task (J. Miller, 1982). In this task, a spatial precue provides partial advance information about which fingers to use for responding. Results indicated a substantial age-related deficit in preparing 2 fingers on 2 hands, but not on 1 hand. This disparate set of findings does not provide strong support for A. A. Hartley's (1993) hypothesis that anterior brain attention systems responsible for selection-for-action are compromised with advancing age. Finally, the authors report that advancing age increasingly slows reaction time more to the inner than to the outer stimulus-response positions. A possible mechanism of this age-related bowed stimulus-response position effect is discussed.

Adult↗

PubMed1998

The relation between morbidity and cognitive performance in a normal aging population.

BACKGROUND: Factors related to physical health have been implicated in both normal and pathological aging of cognitive abilities. To substantiate this notion, we studied existing morbidity, as diagnosed by the general practitioner according to well-defined criteria, as a potential predictor of cognitive test performance. METHODS: A sample of 1360 individuals, aged 24-81 years and living in the community, was stratified for age, sex, and general ability. Active and total morbidity in this group were classified according to the International Classification of Primary Care. Neurocognitive tests were used to assess the domains of verbal memory, sensorimotor speed, and cognitive flexibility. RESULTS: Multiple regression analyses with adjustment for age, sex, and educational level showed both insulin-dependent and noninsulin-dependent diabetes to be negatively associated with all cognitive measures. More specific negative associations were found for chronic bronchitis (performance speed) and presbyacusia (memory). Single or aggregated cardiovascular morbidity (including hypertension) was unrelated to test performance. CONCLUSIONS: Existing morbidity as a whole contributes only modestly (up to 3.5%) to total variance in cognitive function. However, some specific, relatively common diseases of the elderly, such as diabetes and chronic bronchitis, may aggravate the age-related decline in cognitive ability.

Adult↗

PubMed1998

Is nondipping in 24 h ambulatory blood pressure related to cognitive dysfunction?

OBJECTIVE: Associations between the outcome of 24 h ambulatory monitoring and cognitive performance were studied in order to evaluate the potential relevance of ambulant blood pressure status to brain function. It was hypothesized that a small daytime-night-time difference in mean blood pressure (nondipping) is associated with reduced cognitive performance, in line with studies in hypertensive subjects that have reported associations between nondipping and target-organ damage. METHODS: The study followed a cross-sectional design and was part of a larger research programme on determinants of cognitive aging (Maastricht Aging Study, MAAS). A group of 115 community residents aged 28-82 years was recruited from a general practice population and screened for cardiovascular events and medication use. All underwent 24 h blood pressure monitoring. Cognitive performance was measured with tests of verbal memory, attention, simple speed and information processing speed. RESULTS: Mean daytime or night-time levels of both systolic and diastolic blood pressure were unrelated to cognitive outcome, when age, sex and educational level were controlled for. Differences between mean daytime and night-time blood pressure (based on both narrow and wide measurement intervals for day and night-time periods) were positively associated with memory function (5-9% of additional variance explained) and one sporadic positive association was found on the sensorimotor speed score (4%). Nondippers (n=15) showed lower levels of both memory and sensorimotor speed scores. CONCLUSIONS: Ambulatory blood pressure status was not associated with cognitive performance. A reduced nocturnal blood pressure drop was associated with quite specific cognitive deficits, but the underlying mechanism remains to be determined.

Adult↗

PubMed1998

An operation under general anesthesia as a risk factor for age-related cognitive decline: results from a large cross-sectional population study.

OBJECTIVE: To evaluate the factor 'operation under general anesthesia' as a possible risk factor for age-related cognitive decline. DESIGN: A retrospective, population-based, cross-sectional study. SETTING: Maastricht Aging Study (MAAS), Maastricht, The Netherlands. PARTICIPANTS: 1257 normal healthy subjects aged 24 to 86 years. Of the 1257 healthy subjects, 946 subjects appeared to have undergone at least one operation under general anesthesia. MEASUREMENTS: The history of an operation under general anesthesia, number of operations, duration of anesthesia, cognitive performance, subjective health, and subjective memory were measured. RESULTS: A history of an operation under general anesthesia, the number of operations, and the total duration of anesthesia significantly contributed to the number of subjective health-related complaints but did not predict cognitive performance or memory complaints. Subjects with a history of an operation under general anesthesia felt less healthy than subjects who had never undergone an operation under general anesthesia. No interactions with age were found. CONCLUSION: The present study found no support for the notion that a history of an operation under general anesthesia is a determinant or risk factor for accelerated age-related cognitive decline.

Adult↗

PubMed1998

[The Maastricht aging study (MAAS). The longitudinal perspective of cognitive aging].

The Maastricht Aging Study (MAAS) was designed to specify the usual and pathological aging of cognitive function. In short, the main questions of MAAS are: who deteriorates when in which aspects of cognitive function, and what biomedical or psychosocial factors can be identified that may act as mediators in this process? The study comprises four independent panel studies in which a group of 1,900 initially healthy individuals are followed for a period of 12 years with respect to health characteristics and neurocognitive status. For this purpose a sample was drawn from a patient register of collaborating general practitioners, stratified by age (range 24 to 81 years), sex and general ability level. Rationale and design of MAAS are discussed and some findings from the cross-sectional baseline measurement are summarized: general aspects of memory and attention in aging, cognitive functioning after brain trauma and general anesthesia, physical condition (fitness, morbidity and vascular risk factors, such as blood pressure) as predictors of cognitive function, and finally cognitive complaints and metamemory.

Adult↗

PubMed1997

Effect of test duration on age-related differences in Stroop interference.

The effect of test duration on age-related differences in Stroop interference was assessed in a large cross-sectional study involving 429 healthy subjects in four age groups (25-35 years, 40-50 years, 55-65 years, 70-80 years). The results show a clear effect of test duration on Stroop interference. The Stroop Color Word Test was run in two parts. The young group performed the first part relatively rapidly but became slower in the second part, whereas the old group showed the reverse effect. The two middle-aged groups did not show differences between the first and second parts of the test. The results are interpreted in terms of a deficit in response inhibition by a controlled processing strategy. A psychological interpretation of the study findings in terms of increased cautiousness appears less probable. The first part of the test, that is, an abridged version of the test, may prove superior to the regular version for both clinical and research purposes.

Adult↗

PubMed1997

Can the blood pressure predict cognitive task performance in a healthy population sample?

OBJECTIVES: To study the relation between the blood pressure and the neurocognitive function within the full adult age range in a large population sample. DESIGN: A cross-sectional study of 936 healthy adults who were recruited from a register of family practices, stratified for age (24-81 years), sex, and occupational level, who took part in a medical and neurocognitive test program. METHODS: The blood pressure status was studied in relation to five measures of cognitive ability, including verbal memory and speed of information processing. Other vascular risk factors were treated as control variables and included smoking, alcohol intake, body mass index, and body fat distribution. The blood pressure was measured five times using an automatic recording technique (with a Dinamap 8100 device). RESULTS: After adjustment for age, sex, and educational level in a hierarchical regression analysis, we found no unequivocal association between the mean systolic and diastolic blood pressures (or any other studied vascular risk factor) and cognitive test performance both for the whole group and for the subgroup of subjects who were not being administered antihypertensive medication and whose medical history did not include cardiovascular events. Stratified analysis within four age levels revealed no age-specific associations between the blood pressure and the cognitive function. Subjects whose blood pressure was within the hypertensive range performed worse than did matched controls at letter digit copying, but not according to other cognitive measures. CONCLUSIONS: With a population-based sample unselected for blood pressure status we found no linear relationship between the actual blood pressure level and various aspects of cognitive performance. Prospective studies are needed to investigate the possibility that the systemic blood pressure load over time is associated with a decline in specific cognitive abilities.

Adult↗

PubMed1997

Aerobic capacity and cognitive performance in a cross-sectional aging study.

In a population unselected for aerobic fitness status, aerobic fitness (VO2max) and its interaction with age were used to predict performance on several cognitive measures known to be affected by chronological age. It was hypothesized that, in particular, cognitively demanding tasks would be sensitive to aerobic capacity. Healthy subjects between 24 and 76 yr of age (N = 132) were recruited from a larger study into determinants of cognitive aging (Maastricht Aging Study-MAAS). All participants took part in a submaximal bicycle ergometer protocol and an extensive neurocognitive examination, including tests of intelligence, verbal memory, and simple and complex cognitive speed. Participants engaged more hours a week in aerobic sports and felt healthier than the nonparticipants of the same age did. No group differences were found in the basic anthropometric characteristics height, weight, and BMI. Two of four subtasks that reflect complex cognitive speed (Stroop color/word interference and Concept Shifting Test) showed main and interaction effects with age of aerobic capacity in a hierarchical regression analysis, accounting for up to 5% of variance in parameter score after correction for age, sex, and intelligence main effects. These findings fit well within a moderator model of aerobic fitness in cognitive aging. They add to the notion that aerobic fitness may selectively and age-dependently act on cognitive processes, in particular those that require relatively large attentional resources.

Adult↗

PubMed1996

Effects of age and gender on discrete and reciprocal aiming movements.

Using a cross-sectional design, this study determined the time course of aging effects on rapid discrete and reciprocal aiming movements in men and women. A total of 80 men and 61 women in good health were classified into six age groups (25, 35, 45, 55, 65, and 75 years). The discrete task required participants to make one discrete aiming movement, whereas the reciprocal task required a series of back-and-forth movements. Results indicated for both aiming tasks that greater age was strongly associated with slower movement times. The significant interaction between age and task indicated that the discrete task showed much larger aging effects (54%) than the reciprocal task (25%). This finding is tentatively interpreted in terms of a reduced efficiency of "on-line" control processes.

Adult↗

PubMed1996

Factors affecting contrasting results between self-reported and performance-based levels of physical limitation.

We have examined the role of socio-demographic variables, cognitive and affective functioning, and personality in discrepancies between performance-based and self-report measures within three domains of physical limitations: motor functioning, hearing and vision. Data are drawn from a community-based sample of 624 persons of 57 years of age and older. The strength of the association between self-reported and performance-based levels of physical limitations is moderate. Socio-demographic variables and levels of cognitive functioning explained some of the discrepancies between self-reported and performance-based vision. Within the domains of motor functioning and hearing, discrepancies were substantially influenced by affective functioning and personality. The discrepancies may reflect bias in perception or true variation in the effect of limitations on daily functioning. Both self-report and performance-based measures seem to complement each other in providing useful information about physical limitations.

Activities of Daily Living↗

PubMed1996

Long-term persisting cognitive sequelae of traumatic brain injury and the effect of age.

This study examined the notion that mild to moderate traumatic brain injury (TBI) may have persistent effects that become evident upon neurocognitive testing in a phase in which the effects of physiological aging become manifest. Neurocognitive performance was tested in 25 middle-aged and 20 old subjects who had sustained mild to moderate TBI, on average, several decades earlier. The TBI subjects regarded themselves as normal and healthy. The performance of the TBI subjects was inferior to that of matched healthy controls on all aspects of primary and secondary memory and on the majority of tests used to measure speed of performance. There was no interaction between the effects of TBI and those of age, and the performance of middle-aged TBI subjects was similar to that of old controls. The results are taken to indicate that TBI sustained earlier in life may cause permanent sequelae in specific domains of cognitive functioning and that it might attenuate the age-related decline in cognitive functioning. Most striking, however, was that these deficits were not perceived as a limiting factor in everyday life, which suggests that coping strategies may be important.

Adaptation, Psychological↗