Utility of the SLUMS as a cognitive screening tool among a nonveteran sample of older adults.

OBJECTIVES: To investigate the concurrent validity of the Saint Louis University Mental Status examination (SLUMS) by comparing the ability of the Mini-Mental State Examination (MMSE) and the SLUMS to predict performance on standard neuropsychological measures of memory and executive functioning. DESIGN: Cross-sectional. SETTING: University-based research clinic. PARTICIPANTS: Community-dwelling adults (N = 170) age 60 years and older (Mage = 73.08; SD = 8.18). MEASUREMENTS: The Trail Making Test (TMT), Rey Auditory Verbal Learning Test, Wisconsin Card Sorting Test (WCST), MMSE, and SLUMS. RESULTS: The distributional properties of the SLUMS and the MMSE were directly compared. The SLUMS showed statistically a smaller mean, lower rank scores, and less skewness than the MMSE. Comparisons of the correlations of the screening tests with the neuropsychological measures indicated that the SLUMS demonstrated stronger relationships with the TMT compared with the MMSE. Multiple regression analyses were conducted to determine the ability of the SLUMS and the MMSE to predict scores on common neuropsychological tests after controlling for demographic variables. Results demonstrated that the SLUMS significantly predicted performance across all measures over the MMSE and demographic variables, with the exception of the WCST's perseverative errors. However, the MMSE does not add to the prediction of neuropsychological functioning over the SLUMS. CONCLUSION: Although the SLUMS and the MMSE are strongly correlated, the SLUMS significantly adds to the prediction of neuropsychological measures beyond the MMSE scores. Our findings suggest that the SLUMS may be an appropriate measure to use as a screening tool among older adults and may have fewer ceiling effects than the MMSE.

Subjective organization, verbal learning, and forgetting across the life span: from 5 to 89.

UNLABELLED: BACKGROUND/STUDY CONTEXT: Previous tests of the relationship between subjective organization during encoding, aging, and recall have produced inconsistent findings. The present study investigates subjective organization and the acquisition and recall of verbal material across the life span (from 5 to 89 years of age) using two measures, the intertrial repetition paired frequency (PF) measure and the unidirectional subjective organization (SO) measure. METHODS: Participants (N = 2656) were administered a version of the Rey Auditory Verbal Learning Test, including a delayed recall trial. Analyses of variance (ANOVAs) were performed to examine the relationship between age and subjective organization and between age and recall. Mediation and growth curve analyses were performed to further examine the relationship between age, verbal acquisition, and subjective organization. RESULTS: Subjective organization was not predictive of verbal forgetting. Deficits in verbal acquisition and subjective organization were detected among children and elderly adults. Mediational analyses showed that age affected the number of words recalled as well as subjective organization, and that subjective organization affected the number of words recalled in children, young adults and elderly. Latent growth curve modeling suggests that increases in subjective organization over time are related to increases in recall over time for each age group. CONCLUSION: Subjective organization is predictive of recall, and both subjective organization and recall are lowest among children and elderly individuals. Age has direct effects on recall but this effect is partially mediated by subjective organization. Brain imaging studies showing increased prefrontal cortex activation during encoding of remembered words bolster our findings that age affects the relationship between verbal learning and organization of material during encoding.

Age effects on emotion recognition in facial displays: from 20 to 89 years of age.

UNLABELLED: BACKGROUND/STUDY CONTEXT: An emotion recognition task that morphs emotional facial expressions from an initial neutral expression to distinct increments of the full emotional expression was administered to 482 individuals, 20 to 89 years of age. METHODS: Participants assessed six basic emotions at 25%, 50%, 75%, and 100% of the full facial expression. RESULTS: Participants in the three oldest age groups (60s, 70s, and 80s) demonstrated decreased performance for the recognition of the fear, anger, and sad emotions. Increased age was associated with increased recognition rates for the disgust expression, whereas no age effect was detected for the happy and surprise expressions. Covariate analyses revealed age effects were reduced by processing speed, but were unaffected by decision-making ability. The effects of age on individual emotions and levels of presentation are discussed. CONCLUSION: These findings suggest that age has the greatest impact on the recognition of the sad emotion and the greatest age effect at the 50% level of presentation across the adult life span.

Age differences in Stroop interference: contributions of general slowing and task-specific deficits.

This study examined the contributions of general slowing and task-specific deficits to age-related changes in Stroop interference. Nine hundred thirty-eight participants aged 20 to 89 years completed an abbreviated Stroop color-naming task and a subset of 281 participants also completed card-sorting, simple reaction time, and choice reaction time tasks. Age-related increases in incongruent color-naming latency and card-sorting perseverative errors were observed. Hierarchical regression analyses showed that the processing speed measures accounted for significant variance on both dependent measures, but that there was also a significant residual effect of age. An additional regression analysis showed that some of the variance in incongruent color-naming, after controlling for processing speed, was shared with the variance in perseverative errors. Overall, findings suggest that the age difference in Stroop interference is partially attributable to general slowing, but is also attributable to age-related changes in task-specific processes such as inhibitory control.

Correlates of individual, and age-related, differences in short-term learning.

Latent growth models were applied to data on multitrial verbal and spatial learning tasks from two independent studies. Although significant individual differences in both initial level of performance and subsequent learning were found in both tasks, age differences were found only in mean initial level, and not in mean learning. In neither task was fluid or crystallized intelligence associated with learning. Although there were moderate correlations among the level parameters across the verbal and spatial tasks, the learning parameters were not significantly correlated with one another across task modalities. These results are inconsistent with the existence of a general (e.g., material-independent) learning ability.

Age-related change in neural processing of time-dependent stimulus features.

Aging is associated with changes in automatic processing of task-irrelevant stimuli, and this may lead to functional disturbances including repeated orienting to nonnovel events and distraction from task. The effect of age on automatic processing of time-dependent stimulus features was investigated by measurement of the auditory mismatch negativity (MMN) in younger (18-23) and older (55-85) adults. Amplitude of MMN recorded during a paradigm involving low-probability deviation in interstimulus interval (from 500 ms to 250 ms) was found to be reduced in the older group at fronto-central sites. This effect was paralleled by, and correlated to, decreased sensory gating efficiency for component N1 recorded during a separate paradigm involving alternate presentation of auditory stimuli at long (9 s) and short (0.5 s) interstimulus intervals. Further, MMN amplitude was correlated to behavioral performance on a small subset of neuropsychological tests, including the Rey Auditory Verbal Learning Test, within a group of healthy older adults. The results support the hypothesis that aging is associated with declines in automatic processing of time-dependent stimulus features, and this is related to cognitive function. These conclusions are considered in the context of age-related declines in prefrontal cortex function and associated increases in susceptibility to task-irrelevant stimuli.

Acquisition, recall, and forgetting of verbal information in long-term memory by young, middle-aged, and elderly individuals.

Memory performance by four age groups (30-45 years, 46-60 years, 61-75 years, and 76-90 years) was compared on a multi-trial verbal recall task with 20-minute and 1-day delay free recall and recognition trials. The rate of acquisition across 5 learning trials was similar for all ages except the youngest group whose performance was constrained by a ceiling effect. The level of acquisition achieved was less in the two oldest groups. Words gained across trials and words lost across trials made similar contributions to the shape of the learning curve for the acquisition trials. Subjective organization decreased with age, but remained strongly related to the number of words recalled during acquisition for all age groups. The two oldest age groups demonstrated significant declines in words recalled on the 20-minute and 1-day delay trials. A subset of the oldest group demonstrated more rapid forgetting at the 1-day delay when participants from all age conditions were matched on acquisition. Thus, many aspects of free recall were impaired with age, and variance measurement of recall showed greater inter-individual differences with increasing age. This increase in individual differences could reflect a single form of age-related memory impairment, or it could indicate that memory impairment in the elderly is due to multiple processes. The importance of testing across the life span and using tests that examine a variety of memory components and processes for establishing norms and clarifying age-related deficits are discussed.

Performance on the Iowa Gambling Task: From 5 to 89 years of age.

The present study focuses on the role of frequency bias and expected value on the learning processes driving performance on the Iowa Gambling Task (IGT) in individuals between 5 and 89 years of age. As in previous studies, children performed poorly on the IGT, were increasingly influenced by frequency of losses during learning, and constantly changed their decisions. Decision-making strategies changed after childhood from erratic behavior to more consistent strategies that promoted expected value of deck choices. Performance deficits as well as a loss frequency bias were found in older adults. However, age-related deficits were distinct between children and older adults. Cognitive modeling analysis indicated that older adults were more likely to forget about recent outcomes and were more consistent than children when selecting decks. Cognitive ability was associated with a modeling parameter for memory as well as IGT performance, suggesting the involvement of a cognitive component in young and middle-aged adult decision making. The interactions of modeling parameters suggested that cognitive changes were the cause of lowered performance in older adults. These analyses suggest critical developments in decision processes during the adolescent years and decline in a cognitive process leading to decision-making deficits after age 60.

Brain responses to emotional images related to cognitive ability in older adults.

Older adults have been shown to exhibit a positivity effect in processing of emotional stimuli, seemingly focusing more on positive than negative information. Whether this reflects purposeful changes or an unintended side effect of declining cognitive abilities is unclear. For the present study, older adults displaying a wide range of cognitive abilities completed measures of attention, visual, and verbal memory; executive functioning and processing speed; as well as a socioemotional measure of time perspective. Regression analyses examined the ability of these variables to predict neural responsivity to select emotional stimuli as measured with the late positive potential (LPP), an event-related brain potential (ERP). Stronger cognitive functioning was associated with higher LPP amplitude in response to negative images (i.e., greater processing). This does not support a voluntary avoidance of negative information processing in older adults for this particular measure of attentional allocation. A model is proposed to reconcile this finding with the extant literature that has demonstrated positivity effects in measures of later, controlled attentional allocation.

Cognitive function predicts neural activity associated with pre-attentive temporal processing.

Temporal processing, or processing time-related information, appears to play a significant role in a variety of vital psychological functions. One of the main confounds to assessing the neural underpinnings and cognitive correlates of temporal processing is that behavioral measures of timing are generally confounded by other supporting cognitive processes, such as attention. Further, much theorizing in this field has relied on findings from clinical populations (e.g., individuals with schizophrenia) known to have temporal processing deficits. In this study, we attempted to avoid these difficulties by comparing temporal processing assessed by a pre-attentive event-related brain potential (ERP) waveform, the mismatch negativity (MMN) elicited by time-based stimulus features, to a number of cognitive functions within a non-clinical sample. We studied healthy older adults (without dementia), as this population inherently ensures more prominent variability in cognitive function than a younger adult sample, allowing for the detection of significant relationships between variables. Using hierarchical regression analyses, we found that verbal memory and executive functions (i.e., planning and conditional inhibition, but not set-shifting) uniquely predicted variance in temporal processing beyond that predicted by the demographic variables of age, gender, and hearing loss. These findings are consistent with a frontotemporal model of MMN waveform generation in response to changes in the temporal features of auditory stimuli.

The recognition of facial expressions: an investigation of the influence of age and cognition.

The present study aimed to investigate changes in facial expression recognition across the lifespan, as well as to determine the influence of fluid intelligence, processing speed, and memory on this ability. Peak performance in the ability to identify facial affect was found to occur in middle-age, with the children and older adults performing the poorest. Specifically, older adults were impaired in their ability to identify fear, sadness, and happiness, but had preserved recognition of anger, disgust, and surprise. Analyses investigating the influence of cognition on emotion recognition demonstrated that cognitive abilities contribute to performance, especially for participants over age 45. However, the cognitive functions did not fully account for the older adults' impairments on expression recognition. Overall, the age-related deficits in facial expression recognition have implications for older adults' use of non-verbal communicative information.

The moderating role of executive functioning in older adults' responses to a reminder of mortality.

In previous research, older adults responded to mortality salience (MS) with increased tolerance, whereas younger persons responded with increased punitiveness. One possible explanation for this is that many older adults adapt to challenges of later life, such as the prospect of mortality, by becoming more flexible. Recent studies suggest that positively oriented adaptation is more likely for older adults with high levels of executive functioning. Thus, we hypothesized that the better an older adult's executive functioning, the more likely MS would result in increased tolerance. Older and younger adults were randomly assigned to MS or control conditions, and then evaluated moral transgressors. As in previous research, younger adults were more punitive after reminders of mortality; executive functioning did not affect their responses. Among older adults, high functioning individuals responded to MS with increased tolerance rather than intolerance, whereas those low in functioning became more punitive.

Age differences in fluid intelligence: contributions of general slowing and frontal decline.

The current study examined the contributions of general slowing and frontal decline to age differences in fluid intelligence. Participants aged 20-89 years completed Block Design, Matrix Reasoning, simple reaction time, choice reaction time, Wisconsin Card Sorting, and Tower of London tasks. Age-related declines in fluid intelligence, speed of processing, and frontal function were observed. Hierarchical regression analyses showed that the processing speed and frontal function measures accounted for significant variance in fluid intelligence performance, but there was also a residual effect of age after controlling for each variable individually as well as both variables. An additional analysis showed that the variance in fluid intelligence that was attributable to processing speed was not fully shared with the variance attributable to frontal function. These findings suggest that the age-related decline in fluid intelligence is due to general slowing and frontal decline, as well as other unidentified factors.

Reproductive strategy, sexual development and attraction to facial characteristics.

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics.

Working memory, inhibition, and fluid intelligence as predictors of performance on Tower of Hanoi and London tasks.

The contributions of working memory, inhibition, and fluid intelligence to performance on the Tower of Hanoi (TOH) and Tower of London (TOL) were examined in 85 undergraduate participants. All three factors accounted for significant variance on the TOH, but only fluid intelligence accounted for significant variance on the TOL. When the contribution of fluid intelligence was accounted for, working memory and inhibition continued to account for significant variance on the TOH. These findings support argument that fluid intelligence contributes to executive functioning, but also show that the executive processes elicited by tasks vary according to task structure.