On age differences in prefrontal function: The importance of emotional/cognitive integration

Inflammatory processes in the prefrontal cortex induced by systemic immune challenge: Focusing on neurons

Peripheral immune challenge induces neurobiological alterations in the brain and related neuropsychiatric symptoms both in humans and other mammals. One of the best known physiological effects of systemic inflammation is sickness behavior. However, in addition to this depression-like state, there are other cognitive outcomes of peripherally induced neuroinflammation that can be linked to the dysfunction of higher-order cortical areas, such as the prefrontal cortex (PFC). As the physiological activity of the PFC is largely based on the balanced interplay of excitatory pyramidal cells and inhibitory interneurons, it may be hypothesized that neuroinflammatory processes result in a shift of excitatory/inhibitory balance, which is a common hallmark of several neuropsychiatric conditions. Indeed, many data suggest that peripherally induced neuroinflammation is strongly associated with molecular and functional changes in PFC neurons leading to disturbances in their synaptic networks. Different experimental approaches may cause some incongruence in the reviewed data. However, it is commonly agreed that acute systemic inflammation leads to changes in the excitatory/inhibitory balance in the PFC by proinflammatory signaling at the brain borders and in the brain parenchyma. These cellular changes result in altered local and brain-wide network activity inducing disturbances in the top-down control of goal-directed behavior and cognition regulated by the PFC. Lipopolysaccharide (LPS)-treated rodents are the most widely used experimental models of peripherally induced neuroinflammation, so the majority of the reviewed data come from studies utilizing the LPS model. This may limit their general interpretation regarding the neuronal effects of peripheral immune activation. In addition, several biological variables (e.g., sex, age) can influence the PFC effects of systemic immune challenge, not only the nature and severity of immune activation. Therefore, it would be desirable to investigate inflammation-related neuronal changes in the PFC using other models of systemic inflammation as well, and to focus on the targeted fine-tuning of the affected cell types via common molecular mechanisms of the immune and nervous systems.

Decline in Emotional Face Recognition Among Elderly People May Reflect Mild Cognitive Impairment

Background

As with cognitive function, the ability to recognize emotions changes with age. In the literature regarding the relationship between recognition of emotion and cognitive function during aging, the effects of predictors such as aging, emotional state, and cognitive domains on emotion recognition are unclear. This study was performed to clarify the cognitive functions underlying recognition of emotional facial expressions, and to evaluate the effects of depressive mood on recognition of emotion in elderly subjects, as well as to reproduce the effects of aging on the recognition of emotional facial expressions.

Materials and Methods

A total of 26 young (mean age = 20.9 years) and 30 elderly subjects (71.6 years) participated in the study. All subjects participated in face perception, face matching, emotion matching, and emotion selection tasks. In addition, elderly subjects were administered a multicomponent cognitive test: the Neurobehavioral Cognitive Status Examination (Cognistat) and the Geriatric Depression Scale-Short Version. We analyzed these factors using multiple linear regression.

Results

There were no significant differences between the two groups in the face perception task, but in the face matching, emotion matching, and emotion selection tasks, elderly subjects showed significantly poorer performance. Among elderly subjects, multiple regression analyses showed that performance on the emotion matching task was predicted by age, emotional status, and cognitive function, but paradoxical relationships were observed between recognition of emotional faces and some verbal functions. In addition, 47% of elderly participants showed cognitive decline in one or more domains, although all of them had total Cognistat scores above the cutoff.

Conclusion

It might be crucial to consider preclinical pathological changes such as mild cognitive impairment when testing for age effects in elderly populations.

Diminished fronto-limbic functional connectivity in child sexual offenders

BACKGROUND

Child sexual abuse and neglect have been related to an increased risk for the development of a wide range of behavioral, psychological, and sexual problems and increased rates of suicidal behavior. Contrary to the large amount of research focusing on the negative mental health consequences of child sexual abuse, very little is known about the characteristics of child sexual offenders and the neuronal underpinnings contributing to child sexual offending.

METHODS AND SAMPLE

This study investigates differences in resting state functional connectivity (rs-FC) between non-pedophilic child sexual offenders (N = 20; CSO-P) and matched healthy controls (N = 20; HC) using a seed-based approach. The focus of this investigation of rs-FC in CSO-P was put on prefrontal and limbic regions highly relevant for emotional and behavioral processing.

RESULTS

Results revealed a significant reduction of rs-FC between the right centromedial amygdala and the left dorsolateral prefrontal cortex in child sexual offenders compared to controls.

CONCLUSION & RECOMMENDATIONS

Given that, in the healthy brain, there is a strong top-down inhibitory control of prefrontal over limbic structures, these results suggest that diminished rs-FC between the amygdala and the dorsolateral prefrontal cortex and may foster sexual deviance and sexual offending. A profound understanding of these concepts should contribute to a better understanding of the occurrence of child sexual offending, as well as further development of more differentiated and effective interventions.

The unity and diversity of executive functions: A systematic review and re-analysis of latent variable studies

Confirmatory factor analysis (CFA) has been frequently applied to executive function measurement since first used to identify a three-factor model of inhibition, updating, and shifting; however, subsequent CFAs have supported inconsistent models across the life span, ranging from unidimensional to nested-factor models (i.e., bifactor without inhibition). This systematic review summarized CFAs on performance-based tests of executive functions and reanalyzed summary data to identify best-fitting models. Eligible CFAs involved 46 samples (N = 9,756). The most frequently accepted models varied by age (i.e., preschool = one/two-factor; school-age = three-factor; adolescent/adult = three/nested-factor; older adult = two/three-factor), and most often included updating/working memory, inhibition, and shifting factors. A bootstrap reanalysis simulated 5,000 samples from 21 correlation matrices (11 child/adolescent; 10 adult) from studies including the three most common factors, fitting seven competing models. Model results were summarized as the mean percent accepted (i.e., average rate at which models converged and met fit thresholds: CFI ≥ .90/RMSEA ≤ .08) and mean percent selected (i.e., average rate at which a model showed superior fit to other models: ΔCFI ≥ .005/.010/ΔRMSEA ≤ -.010/-.015). No model consistently converged and met fit criteria in all samples. Among adult samples, the nested-factor was accepted (41-42%) and selected (8-30%) most often. Among child/adolescent samples, the unidimensional model was accepted (32-36%) and selected (21-53%) most often, with some support for two-factor models without a differentiated shifting factor. Results show some evidence for greater unidimensionality of executive function among child/adolescent samples and both unity and diversity among adult samples. However, low rates of model acceptance/selection suggest possible bias toward the publication of well-fitting but potentially nonreplicable models with underpowered samples. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Effects of age on the identification of emotions in facial expressions: a meta-analysis

Background

Emotion identification is a fundamental component of social cognition. Although it is well established that a general cognitive decline occurs with advancing age, the effects of age on emotion identification is still unclear. A meta-analysis by Ruffman and colleagues (2008) explored this issue, but much research has been published since then, reporting inconsistent findings.

Methods

To examine age differences in the identification of facial expressions of emotion, we conducted a meta-analysis of 24 empirical studies (N = 1,033 older adults, N = 1,135 younger adults) published after 2008. Additionally, a meta-regression analysis was conducted to identify potential moderators.

Results

Results show that older adults less accurately identify facial expressions of anger, sadness, fear, surprise, and happiness compared to younger adults, strengthening the results obtained by Ruffman et al. (2008). However, meta-regression analyses indicate that effect sizes are moderated by sample characteristics and stimulus features. Importantly, the estimated effect size for the identification of fear and disgust increased for larger differences in the number of years of formal education between the two groups.

Discussion

We discuss several factors that might explain the age-related differences in emotion identification and suggest how brain changes may account for the observed pattern. Furthermore, moderator effects are interpreted and discussed.

Chiari 1000 Registry Project: assessment of surgical outcome on self-focused attention, pain, and delayed recall

BACKGROUND

Prior research has typically found a negative relationship between chronic pain and memory, and we examined whether cognitive control processes (e.g. reflection and rumination) moderated this relationship in individuals with Chiari malformation Type I (CM). CM is a neurological condition in which the cerebellar tonsils descend into the medullary and upper cervical spine regions potentially resulting in severe headaches and neck pain.

METHODS

CM patients who had (n = 341) and had not (n = 297) undergone decompression surgery completed the McGill Pain Questionnaire-Short Form-Revised (SF-MPQ-2), the Rey Auditory Verbal Learning Test (RAVLT), and the Rumination-Reflection Questionnaire (RRQ). Immediate recall scores were compared to those of 102 healthy controls, and delayed recall performance was compared across other variables within the CM group.

RESULTS

CM patients performed more poorly on immediate recall than did controls. Within CM patients, we observed main effects for reflection and age, and a pain x reflection x surgical status (surgery v. no surgery) interaction in which non-decompressed individuals with low levels of pain and high levels of reflection showed superior delayed recall relative to non-decompressed individuals with higher pain and all decompressed individuals.

CONCLUSIONS

CM patients show an immediate recall deficit relative to controls, regardless of surgical status. High levels of reflection were associated with better delayed recall performance in non-decompressed CM patients with lower pain levels. High levels of chronic pain may overwhelm increased focused attention abilities, but higher levels of reflection partially overcome the distracting effects of pain and this may represent a type of resilience.

Emotional arousal deficit or emotional regulation bias? An electrophysiological study of age-related differences in emotion perception

Background/Study context: Adult age differences in emotion processing have been attributed to age-related decline in earlier emotional perception and age-related bias in later emotional regulation. Yet, the relationship between the processes of early emotion perception and bias in emotional regulation and their influence on behavioral outcomes remains unclear. Event-related potentials (ERPs) have the temporal precision to allow for the online measure of neurophysiological activity and provide potential insight into the complex dynamics of emotion processing and aging.

METHODS

ERPs were used as the primary measure to examine the hypotheses that younger adults will differ in emotional arousal and emotional bias as represented by the early P1 waveform and later P3 waveform, respectively. Thirty-two younger and older adults (16 each) performed a facial emotion discrimination task in which they identified standardized angry, happy, or neutral expressions of faces from the NimStim database.

RESULTS

Younger adults showed a greater P1 ERP for angry faces relative to happy faces at parietal channels, while older adults did not exhibit any emotional modulation of the P1. In contrast, both younger and older adults showed a greater late P3 ERP for angry faces compared to happy faces.

CONCLUSION

The authors' results provide evidence for an age-related deficit in early emotion perception and autonomic arousal. Younger adults, but not older adults, exhibited a pattern of neurophysiological activity believed to reflect preconscious and reflexive identification of threat. Despite these age group differences in early emotion processing, younger and older adults did not exhibit differences in neurophysiological processes believed to reflect emotion regulation.

Meta-Analytic Evidence for a Reversal Learning Effect on the Iowa Gambling Task in Older Adults

Iowa Gambling Task (IGT) is one of the most widely used tools to assess economic decision-making. However, the research tradition on aging and the Iowa Gambling Task (IGT) has been mainly focused on the overall performance of older adults in relation to younger or clinical groups, remaining unclear whether older adults are capable of learning along the task. We conducted a meta-analysis to examine older adults' decision-making on the IGT, to test the effects of aging on reversal learning (45 studies) and to provide normative data on total and block net scores (55 studies). From the accumulated empirical evidence, we found an average total net score of 7.55 (±25.9). We also observed a significant reversal learning effect along the blocks of the IGT, indicating that older adults inhibit the prepotent response toward immediately attractive options associated with high losses, in favor of initially less attractive options associated with long-run profit. During block 1, decisions of older adults led to a negative gambling net score, reflecting the expected initial pattern of risk-taking. However, the shift toward more safe options occurred between block 2 (small-to-medium effect size) and blocks 3, 4, 5 (medium-to-large effect size). These main findings highlight that older adults are able to move from the initial uncertainty, when the possible outcomes are unknown, to decisions based on risk, when the outcomes are learned and may be used to guide future adaptive decision-making.

Gaze Behavior Consistency among Older and Younger Adults When Looking at Emotional Faces

The identification of non-verbal emotional signals, and especially of facial expressions, is essential for successful social communication among humans. Previous research has reported an age-related decline in facial emotion identification, and argued for socio-emotional or aging-brain model explanations. However, more perceptual differences in the gaze strategies that accompany facial emotional processing with advancing age have been under-explored yet. In this study, 22 young (22.2 years) and 22 older (70.4 years) adults were instructed to look at basic facial expressions while their gaze movements were recorded by an eye-tracker. Participants were then asked to identify each emotion, and the unbiased hit rate was applied as performance measure. Gaze data were first analyzed using traditional measures of fixations over two preferential regions of the face (upper and lower areas) for each emotion. Then, to better capture core gaze changes with advancing age, spatio-temporal gaze behaviors were deeper examined using data-driven analysis (dimension reduction, clustering). Results first confirmed that older adults performed worse than younger adults at identifying facial expressions, except for "joy" and "disgust," and this was accompanied by a gaze preference toward the lower-face. Interestingly, this phenomenon was maintained during the whole time course of stimulus presentation. More importantly, trials corresponding to older adults were more tightly clustered, suggesting that the gaze behavior patterns of older adults are more consistent than those of younger adults. This study demonstrates that, confronted to emotional faces, younger and older adults do not prioritize or ignore the same facial areas. Older adults mainly adopted a focused-gaze strategy, consisting in focusing only on the lower part of the face throughout the whole stimuli display time. This consistency may constitute a robust and distinctive "social signature" of emotional identification in aging. Younger adults, however, were more dispersed in terms of gaze behavior and used a more exploratory-gaze strategy, consisting in repeatedly visiting both facial areas.

Aging and risky decision-making: New ERP evidence from the Iowa Gambling Task

Several pieces of evidence have highlighted the presence of an age-related decline in risky decision-making (DM), but the reason of this decline is still unclear. The aim of the present study was to investigate the neural correlates of feedback processing in risky DM. Twenty-one younger (age <50 years) and 15 older (age >50 years) adults were tested with the Iowa Gambling Task (IGT) during Event Related Potentials (ERP) recording. The analysis was focused on the feedback-related negativity (FRN) and P3, two ERP components that represent different stages of feedback processing. Behavioral results revealed that older adults, despite showing a significant learning trend, completed the IGT with a gain of a smaller amount of money compared to the younger ones. ERP results revealed that while the FRN response was comparable in the two groups, the P3 amplitude was significantly reduced after negative feedback in older adults, compared with the younger ones. Furthermore, the difference in the P3 amplitude evoked by positive and negative feedback was significantly correlated with age. Hence, the present findings suggest that older adults seem to be less willing to shift attention from positive to negative information, and that this relevant change in the later stages of feedback processing could be the cause of a poor performance in risky DM contexts.

Visual Acuity does not Moderate Effect Sizes of Higher-Level Cognitive Tasks

BACKGROUND/STUDY CONTEXT

Declining visual capacities in older adults have been posited as a driving force behind adult age differences in higher-order cognitive functions (e.g., the "common cause" hypothesis of Lindenberger & Baltes, 1994, Psychology and Aging, 9, 339-355). McGowan, Patterson, and Jordan (2013, Experimental Aging Research, 39, 70-79) also found that a surprisingly large number of published cognitive aging studies failed to include adequate measures of visual acuity. However, a recent meta-analysis of three studies (La Fleur and Salthouse, 2014, Psychonomic Bulletin & Review, 21, 1202-1208) failed to find evidence that visual acuity moderated or mediated age differences in higher-level cognitive processes. In order to provide a more extensive test of whether visual acuity moderates age differences in higher-level cognitive processes, we conducted a more extensive meta-analysis of topic.

METHODS

Using results from 456 studies, we calculated effect sizes for the main effect of age across four cognitive domains (attention, executive function, memory, and perception/language) separately for five levels of visual acuity criteria (no criteria, undisclosed criteria, self-reported acuity, 20/80-20/31, and 20/30 or better).

RESULTS

As expected, age had a significant effect on each cognitive domain. However, these age effects did not further differ as a function of visual acuity criteria.

CONCLUSION

The current meta-analytic, cross-sectional results suggest that visual acuity is not significantly related to age group differences in higher-level cognitive performance-thereby replicating La Fleur and Salthouse (2014). Further efforts are needed to determine whether other measures of visual functioning (e.g., contrast sensitivity, luminance) affect age differences in cognitive functioning.

Geriatric Suicide Attempt and Risk of Subsequent Dementia: A Nationwide Longitudinal Follow-up Study in Taiwan

OBJECTIVE

It was unclear whether older people without dementia who attempted suicide were at increased risk of subsequently developing dementia.

METHODS

Using the Taiwan National Health Insurance Research Database, 1,189 patients aged ≥ 65 years who attempted suicide and 4,756 age- and sex-matched control subjects were enrolled in our study and followed to the end of 2011. Those who developed dementia during the follow-up were identified.

RESULTS

Cox regression analysis, after adjusting for demographic data and medical comorbidities, found that geriatric suicide attempt was associated with an increased risk of subsequent dementia (HR: 7.40; 95% CI: 6.11-8.97; Wald χ² = 414.87, df = 1, p < 0.001). Both patients aged between 65 and 79 years (HR: 7.74; 95% CI: 6.17-9.71; Wald χ² = 312.62, df = 1, p < 0.001) and patients aged ≥ 80 years (HR: 6.94; 95% CI: 4.73-10.17; Wald χ² = 97.78, df = 1, p < 0.001) who attempted suicide had an increased risk of developing dementia in later life.

CONCLUSION

The elderly who attempted suicide were prone to developing dementia in later life, independent of depression and medical comorbidities. Further studies are necessary to clarify the underlying mechanisms between geriatric suicide and dementia and whether the prompt intervention for geriatric suicide may reduce this risk.

Altered Value Coding in the Ventromedial Prefrontal Cortex in Healthy Older Adults

Previous work suggests that aging is associated with changes in risk taking but less is known about their underlying neural basis, such as the potential age differences in the neural processing of value and risk. The goal of the present study was to investigate adult age differences in functional neural responses in a naturalistic risk-taking task. Twenty-six young adults and 27 healthy older adults completed the Balloon Analogue Risk Task while undergoing functional magnetic resonance imaging. Young and older adults showed similar overt risk-taking behavior. Group comparison of neural activity in response to risky vs. control stimuli revealed similar patterns of activation in the bilateral striatum, anterior insula (AI) and ventromedial prefrontal cortex (vmPFC). Group comparison of parametrically modulated activity in response to continued pumping similarly revealed comparable results for both age groups in the AI and, potentially, the striatum, yet differences emerged for regional activity in the vmPFC. At whole brain level, insular, striatal and vmPFC activation was predictive of behavioral risk taking for young but not older adults. The current results are interpreted and discussed as preserved neural tracking of risk and reward in the AI and striatum, respectively, but altered value coding in the vmPFC in the two age groups. The latter finding points toward older adults exhibiting differential vmPFC-related integration and value coding. Furthermore, neural activation holds differential predictive validity for behavioral risk taking in young and older adults.

Age-Related Changes in the Processing of Emotional Faces in a Dual-Task Paradigm

Background/ Study Context: Age-related changes appear to affect the ability to identify emotional facial expressions in dual-task conditions (i.e., while simultaneously performing a second visual task). The level of interference generated by the secondary task depends on the phase of emotional processing affected by the interference and the nature of the secondary task. The aim of the present study was to investigate the effect of these variables on age-related changes in the processing of emotional faces.

METHODS

The identification of emotional facial expressions (EFEs) was assessed in a dual-task paradigm using the following variables: (a) the phase during which interference was applied (encoding vs. retrieval phase); and (b) the nature of the interfering stimulus (visuospatial vs. verbal). The sample population consisted of 24 healthy aged adults (mean age = 75.38) and 40 younger adults (mean age = 26.90). The accuracy of EFE identification was calculated for all experimental conditions.

RESULTS

Consistent with our hypothesis, the performance of the older group was poorer than that of the younger group in all experimental conditions. Dual-task performance was poorer when the interference occurred during the encoding phase of emotional face processing and when both tasks were of the same nature (i.e., when the experimental condition was more demanding in terms of attention).

CONCLUSIONS

These results provide empirical evidence of age-related deficits in the identification of emotional facial expressions, which may be partially explained by the impairment of cognitive resources specific to this task. These findings may account for the difficulties experienced by the elderly during social interactions that require the concomitant processing of emotional and environmental information.

Age-related emotional bias in processing two emotionally valenced tasks

Previous studies suggest that older adults process positive emotions more efficiently than negative emotions, whereas younger adults show the reverse effect. We examined whether this age-related difference in emotional bias still occurs when attention is engaged in two emotional tasks. We used a psychological refractory period paradigm and varied the emotional valence of Task 1 and Task 2. In both experiments, Task 1 was emotional face discrimination (happy vs. angry faces) and Task 2 was sound discrimination (laugh, punch, vs. cork pop in Experiment 1 and laugh vs. scream in Experiment 2). The backward emotional correspondence effect for positively and negatively valenced Task 2 on Task 1 was measured. In both experiments, younger adults showed a backward correspondence effect from a negatively valenced Task 2, suggesting parallel processing of negatively valenced stimuli. Older adults showed similar negativity bias in Experiment 2 with a more salient negative sound ("scream" relative to "punch"). These results are consistent with an arousal-bias competition model [Mather and Sutherland (Perspectives in Psychological Sciences 6:114-133, 2011)], suggesting that emotional arousal modulates top-down attentional control settings (emotional regulation) with age.

The Affective Neuroscience of Aging

Although aging is associated with clear declines in physical and cognitive processes, emotional functioning fares relatively well. Consistent with this behavioral profile, two core emotional brain regions, the amygdala and ventromedial prefrontal cortex, show little structural and functional decline in aging, compared with other regions. However, emotional processes depend on interacting systems of neurotransmitters and brain regions that go beyond these structures. This review examines how age-related brain changes influence processes such as attending to and remembering emotional stimuli, regulating emotion, and recognizing emotional expressions, as well as empathy, risk taking, impulsivity, behavior change, and attentional focus.

Neural evidence for moral intuition and the temporal dynamics of interactions between emotional processes and moral cognition

Behavioral and neurological studies have revealed that emotions influence moral cognition. Although moral stimuli are emotionally charged, the time course of interactions between emotions and moral judgments remains unknown. In the present study, we investigated the temporal dynamics of the interaction between emotional processes and moral cognition. The results revealed that when making moral judgments, the time course of the event-related potential (ERP) waveform was significantly different between high emotional arousal and low emotional arousal contexts. Different stages of processing were distinguished, showing distinctive interactions between emotional processes and moral reasoning. The precise time course of moral intuition and moral reasoning sheds new light on theoretical models of moral psychology. Specifically, the N1 component (interpreted as representing moral intuition) did not appear to be influenced by emotional arousal. However, the N2 component and late positive potential were strongly affected by emotional arousal; the slow wave was influenced by both emotional arousal and morality, suggesting distinct moral processing at different emotional arousal levels.

Aging and loss decision making: increased risk aversion and decreased use of maximizing information, with correlated rationality and value maximization

We investigated how adult aging specifically alters economic decision-making, focusing on examining alterations in uncertainty preferences (willingness to gamble) and choice strategies (what gamble information influences choices) within both the gains and losses domains. Within each domain, participants chose between certain monetary outcomes and gambles with uncertain outcomes. We examined preferences by quantifying how uncertainty modulates choice behavior as if altering the subjective valuation of gambles. We explored age-related preferences for two types of uncertainty, risk, and ambiguity. Additionally, we explored how aging may alter what information participants utilize to make their choices by comparing the relative utilization of maximizing and satisficing information types through a choice strategy metric. Maximizing information was the ratio of the expected value of the two options, while satisficing information was the probability of winning. We found age-related alterations of economic preferences within the losses domain, but no alterations within the gains domain. Older adults (OA; 61–80 years old) were significantly more uncertainty averse for both risky and ambiguous choices. OA also exhibited choice strategies with decreased use of maximizing information. Within OA, we found a significant correlation between risk preferences and choice strategy. This linkage between preferences and strategy appears to derive from a convergence to risk neutrality driven by greater use of the effortful maximizing strategy. As utility maximization and value maximization intersect at risk neutrality, this result suggests that OA are exhibiting a relationship between enhanced rationality and enhanced value maximization. While there was variability in economic decision-making measures within OA, these individual differences were unrelated to variability within examined measures of cognitive ability. Our results demonstrate that aging alters economic decision-making for losses through changes in both individual preferences and the strategies individuals employ.

Predicting Performance on the Columbia Card Task

Behavioral measures of risky decision making are frequently used by researchers and clinicians; however, most of these measures are strongly associated with personality characteristics and state mood. The present study sought to examine personality, mood, and executive function predictors of performance on a newer measure of decision making, the Columbia Card Task (CCT). Participants were 489 undergraduate students who completed either the hot or cold version of the CCT as well as measures of state mood, impulsive sensation seeking, behavioral inhibition and activation systems, and executive functions (Wisconsin Card Sort Task; Digit Span). Results indicated that performance on the CCT-cold was predicted by Wisconsin Card Sort Task errors, and Digit Span predicted the CCT-hot. In addition, significant correlations were found between the CCT information use variables and the predictor variables. Implications for the utility of the CCT as a clinical instrument and its relationship with other measures of decision making are discussed.

Task-specific and general cognitive effects in Chiari malformation type I

OBJECTIVE

Our objective was to use episodic memory and executive function tests to determine whether or not Chiari Malformation Type I (CM) patients experience cognitive dysfunction.

BACKGROUND

CM is a neurological syndrome in which the cerebellum descends into the cervical spine causing neural compression, severe headaches, neck pain, and number of other physical symptoms. While primarily a disorder of the cervico-medullary junction, both clinicians and researchers have suspected deficits in higher-level cognitive function.

DESIGN AND METHODS

We tested 24 CM patients who had undergone decompression neurosurgery and 24 age- and education-matched controls on measures of immediate and delayed episodic memory, as well as three measures of executive function.

RESULTS

The CM group showed performance decrements relative to the controls in response inhibition (Stroop interference), working memory computational speed (Ospan), and processing speed (automated digit symbol substitution task), but group differences in recall did not reach statistical significance. After statistical control for depression and anxiety scores, the group effects for working memory and processing speed were eliminated, but not for response inhibition. This response inhibition difference was not due to overall general slowing for the CM group, either, because when controls' data were transformed using the linear function fit to all of the reaction time tasks, the interaction with group remained statistically significant. Furthermore, there was a multivariate group effect for all of the response time measures and immediate and delayed recall after statistical control of depression and anxiety scores.

CONCLUSION

These results suggest that CM patients with decompression surgery exhibit cognitive dysfunction compared to age- and education-matched controls. While some of these results may be related to anxiety and depression (likely proxies for chronic pain), response inhibition effects, in particular, as well as a general cognitive deficit persisted even after control for anxiety and decompression.

Effects of short-term environmental hyperthermia on patterns of cerebral blood flow

Environmental hyperthermia is a very common risk factor for many occupations, however, its potential influences on cerebral circulation remain obscure. In this study, 20 participants underwent two simulated environmental thermal conditions (50 °C/25 °C, 1 h), and their cerebral blood flows (CBFs) were quantified using a pseudo-continuous arterial spin labeling (ASL) MR imaging. During the experiment, the physiological parameters, including rectal temperature, arterial blood pressure and weight loss, heart rate and respiration rate, were recorded, and a visual analog scale (VAS) test was performed during both conditions to evaluate the psychological state including vigilance, anxiety, vigor, confidence, anger, nervousness, drowsiness, and loquacity. After scanning, a highly-demanding attentional task--the psychomotor vigilance test (PVT) was performed for behavioral performance evaluation. Compared with that during normothermic condition, the global CBF (gCBF) during hyperthermic condition showed a tendency of decrease, but no significant differences. Regional CBFs (rCBFs) were significantly altered mainly in the prefrontal cortex, somatosensory areas and limbic system. Physiological detection revealed significantly decreased diastolic pressure and systolic pressure and accelerated respiration rate. Furthermore, linear multivariate regression analysis showed that altered rCBFs in several regions could be predicted by physiological (systolic pressure, rectal temperature) and psychological (vigilance, drowsiness, nervousness, anger) changes. And PVT revealed significantly slower attentional reaction during hyperthermia, and the longer reaction time was correlated with the altered rCBF in the left dorsolateral prefrontal cortex (DLPFC). These findings suggested that during short-term hyperthermia gCBF might remain relatively stable under the integrated effect of physiological changes and cerebral auto-regulation, rather than decreased solely dependently on hyperthermia-induced physiological changes. Furthermore, altered regional blood distribution might be accounted for neural activity of thermal sensation and regulation, mood state and cognitive changes.

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.

Age-related changes in the functional network underlying specific and general autobiographical memory retrieval: a pivotal role for the anterior cingulate cortex

Age-related changes in autobiographical memory (AM) recall are characterized by a decline in episodic details, while semantic aspects are spared. This deleterious effect is supposed to be mediated by an inefficient recruitment of executive processes during AM retrieval. To date, contrasting evidence has been reported on the neural underpinning of this decline, and none of the previous studies has directly compared the episodic and semantic aspects of AM in elderly. We asked 20 young and 17 older participants to recall specific and general autobiographical events (i.e., episodic and semantic AM) elicited by personalized cues while recording their brain activity by means of fMRI. At the behavioral level, we confirmed that the richness of episodic AM retrieval is specifically impoverished in aging and that this decline is related to the reduction of executive functions. At the neural level, in both age groups, we showed the recruitment of a large network during episodic AM retrieval encompassing prefrontal, cortical midline and posterior regions, and medial temporal structures, including the hippocampus. This network was very similar, but less extended, during semantic AM retrieval. Nevertheless, a greater activity was evidenced in the dorsal anterior cingulate cortex (dACC) during episodic, compared to semantic AM retrieval in young participants, and a reversed pattern in the elderly. Moreover, activity in dACC during episodic AM retrieval was correlated with inhibition and richness of memories in both groups. Our findings shed light on the direct link between episodic AM retrieval, executive control, and their decline in aging, proposing a possible neuronal signature. They also suggest that increased activity in dACC during semantic AM retrieval in the elderly could be seen as a compensatory mechanism underpinning successful AM performance observed in aging. These results are discussed in the framework of recently proposed models of neural reorganization in aging.

ADHD symptoms across the lifespan in a population-based Swedish sample aged 65 to 80

BACKGROUND

The purpose of the study was to examine the attention deficit hyperactivity disorder (ADHD) symptomatology across the lifespan by comparing older individuals' self-reports about current ADHD symptoms and symptoms in childhood.

METHODS

The 25-item Wender Utah Rating Scale (WURS) was initially administered in a population-based sample of 1,599 persons aged 65-80 years. We also asked about current health, memory, and problems in childhood. Based on their WURS scores (below and above 36), we randomly drew two subsamples, each with 30 individuals. They were followed up by the Wender Riktad ADHD Symtom Skala (WRASS)-scale, a Swedish version of the Targeted Attention Deficit Disorder Rating Scale (TADDS).

RESULTS

Our main finding was that higher WURS scores were significantly related to higher scores on the WRASS scale, indicating persistence of self-reported ADHD symptoms over the whole lifespan. Among those with a WURS score of 36 or more, 16 (53.3%) individuals scored 70 or more; the clinical cut-off used in Sweden. None of the individuals with a WURS score below 36 scored higher than 70 on the WRASS scale.

CONCLUSIONS

Our findings support the idea of a significant persistence of ADHD symptoms from childhood to old age. The results encourage studies of ADHD using a lifespan perspective, particularly in examining ADHD symptoms in old age.

Electrophysiological evidence for adult age-related sparing and decrements in emotion perception and attention

The present study examined adult age differences in processing emotional faces using a psychological refractory period paradigm. We used both behavioral and event-related potential (P1 component) measures. Task 1 was tone discrimination (fuzzy vs. pure tones) and Task 2 was emotional facial discrimination (“happy” vs. “angry” faces). The stimulus onset asynchrony (SOA) between the two tasks was 100, 300, and 900 ms. Earlier research observed larger age deficits in emotional facial discrimination for negative (angry) than for positive (happy) faces (Baena et al., 2010). Thus, we predicted that older adults would show decreased attentional efficiency in carrying out dual-task processing on the P1 (a component linked to amygdalar modulation of visual perception; Rotshtein et al., 2010). Both younger and older groups showed significantly higher P1 amplitudes at 100- and 300-ms SOAs than at the 900-ms SOA, and this suggests that both age groups could process Task 2 faces without central attention. Also, younger adults showed significantly higher P1 activations for angry than for happy faces, but older adults showed no difference. These results are consistent with the idea that younger adults exhibited amygdalar modulation of visual perception, but that older adults did not.

Exploring the evolution of post-acupuncture resting-state networks combining ICA and multivariate Granger causality

The sustained effects of acupuncture have been widely applied to clinical treatment, thus it can be assumed that the relatively functional specificity of acupoints may evolve as the function of time. In this study, we originally combined ICA and multivariate Granger causality analysis to explore the causal interactions within and among the post-acupuncture resting-state networks (RSNs) at a hearing-related acupoint GB40, with the cognition-related acupoint KI3 as a control. Following acupuncture at GB40, the superior temporal gyrus (STG) and anterior insula (AI) within auditory network appeared persistent bidirectional connection with maximal strength, and the interactions between the auditory network and others became more complex as time passed. For KI3, both the superior parietal lobule (SPL) and dorsolateral prefrontal cortex (DLPFC), as vital nuclei of cognitive function, emerged increased causal outflows and inflows as time went on. We concluded that acupuncture at different acupoints may exert different evolutive effects on causal interactions within and across the RSNs during segmented post-stimulus resting states.

Theory of Mind in normal ageing and neurodegenerative pathologies

This paper reviews findings in three subcomponents of social cognition (i.e., Theory of Mind, facial emotion recognition, empathy) during ageing. Changes over time in social cognition were evaluated in normal ageing and in patients with various neurodegenerative pathologies, such as Alzheimer's disease, mild cognitive impairment, frontal and temporal variants of frontotemporal lobar degeneration and Parkinson's disease. Findings suggest a decline in social cognition with normal ageing, a decline that is at least partially independent of a more general cognitive or executive decline. The investigation of neurodegenerative pathologies showing specific deficits in Theory of Mind in relation to damage to specific cerebral regions led us to suggest a neural network involved in Theory of Mind processes, namely a fronto-subcortical loop linking the basal ganglia to the regions of the frontal lobes.

A latent variable approach to executive control in healthy ageing

It is a well-established finding that the central executive is fractionated in at least three separable component processes: Updating, Shifting, and Inhibition of information (Miyake et al., 2000). However, the fractionation of the central executive among the elderly has been less well explored, and Miyake's et al. latent structure has not yet been integrated with other models that propose additional components, such as access to long-term information. Here we administered a battery of classic and newer neuropsychological tests of executive functions to 122 healthy individuals aged between 48 and 91 years. The test scores were subjected to a latent variable analysis (LISREL), and yielded four factors. The factor structure obtained was broadly consistent with Miyake et al.'s three-factor model. However, an additional factor, which was labeled 'efficiency of access to long-term memory', and a mediator factor ('speed of processing') were apparent in our structural equation analysis. Furthermore, the best model that described executive functioning in our sample of healthy elderly adults included a two-factor solution, thus indicating a possible mechanism of dedifferentiation, which involves larger correlations and interdependence of latent variables as a consequence of cognitive ageing. These results are discussed in the light of current models of prefrontal cortex functioning.

Age differences in risky choice: a meta-analysis

Does risk taking change as a function of age? We conducted a systematic literature search and found 29 comparisons between younger and older adults on behavioral tasks thought to measure risk taking (N= 4,093). The reports relied on various tasks differing in several respects, such as the amount of learning required or the choice framing (gains vs. losses). The results suggest that age-related differences vary considerably as a function of task characteristics, in particular the learning requirements of the task. In decisions from experience, age-related differences in risk taking were a function of decreased learning performance: older adults were more risk seeking compared to younger adults when learning led to risk-avoidant behavior, but were more risk averse when learning led to risk-seeking behavior. In decisions from description, younger adults and older adults showed similar risk-taking behavior for the majority of the tasks, and there were no clear age-related differences as a function of gain/loss framing. We discuss limitations and strengths of past research and provide suggestions for future work on age-related differences in risk taking.

Parallel declines in cognition, motivation, and locomotion in aging mice: association with immune gene upregulation in the medial prefrontal cortex

Aging in humans is associated with parallel changes in cognition, motivation, and motoric performance. Based on the human aging literature, we hypothesized that this constellation of age-related changes is mediated by the medial prefrontal cortex and that it would be observed in aging mice. Toward this end, we performed detailed assessments of cognition, motivation, and motoric behavior in aging mice. We assessed behavioral and cognitive performance in C57Bl/6 mice aged 6, 18, and 24 months, and followed this with microarray analysis of tissue from the medial prefrontal cortex and analysis of serum cytokine levels. Multivariate modeling of these data suggested that the age-related changes in cognition, motivation, motor performance, and prefrontal immune gene expression were highly correlated. Peripheral cytokine levels were also correlated with these variables, but less strongly than measures of prefrontal immune gene upregulation. To determine whether the observed immune gene expression changes were due to prefrontal microglial cells, we isolated CD11b-positive cells from the prefrontal cortex and subject them to next-generation RNA sequencing. Many of the immune changes present in whole medial prefrontal cortex were enriched in this cell population. These data suggest that, as in humans, cognition, motivation, and motoric performance in the mouse change together with age and are strongly associated with CNS immune gene upregulation.

Do sleep complaints contribute to age-related cognitive decline?

The cognitive changes that occur with ageing are usually referred to as 'age-related cognitive decline'. The most pronounced changes may be found in the executive functions that require integrity of the prefrontal cortical circuitry. With age, sleep also changes profoundly, with more sleep fragmentation, earlier awakenings and less slow wave sleep as its main features. Interestingly, experimental sleep deprivation studies in healthy young adults showed a particularly consistent effect on executive functions, suggesting that sleep problems might contribute to the cognitive changes accompanying older age. We here investigate this possibility by reviewing reports on age-related and insomnia-related changes in cognition and brain function and structure, as found in studies investigating subjective complaints, objective functioning in everyday life, neuropsychological assessment, psychometry, structural and functional magnetic resonance imaging, electroencephalography, positron emission tomography and transcranial magnetic stimulation. The chapter focuses on the 'normal' age-related sleep changes that are experienced as insomnia - that is, fragmentation of sleep, more superficial sleep, more wake after sleep onset and earlier awakenings - rather than on specific sleep disturbances as sleep-disordered breathing, restless legs or periodic limb movements during sleep, for all of which the risk increases with age. It turned out that relatively few studies directly addressed the question whether elderly with different degrees of sleep complaints are differentially affected by 'age-related cognitive decline'. Still, several similarities between age-related and insomnia-related cognitive and brain changes are apparent, notably with respect to performance requiring integrity of the prefrontal cortical system. We suggest that at least part of what we regard as age-related changes may, in fact, be due to poor sleep, which is in some cases a treatable condition. Further research directly comparing aged good sleepers versus aged insomniacs will need to elucidate how sleep disturbances are involved in the cognitive, structural and functional changes observed with increasing age. The findings suggest that discrimination of subtypes of poor sleep at high age will aid in understanding the mechanisms by which it affects cognition and brain function.