Increased functional integration of emotional control network in late adulthood.

Across the adult lifespan, there are changes in how emotions are perceived and regulated. As individuals age, there is an observed improvement in emotion regulation and overall quicker recovery from negative emotions. While previous studies have shown differences in emotion processing in late adulthood, the corresponding differences in large-scale brain networks remain largely underexplored. By utilizing large-scale datasets such as the Human Connectome Project (HCP-Aging, N=621) and Cambridge Centre for Ageing and Neuroscience (Cam-CAN, N=333), we were able to investigate how emotion regulation networks' functional topography differs across the entire adult lifespan. Based on previous meta-analytic work that identified four large-scale functional brain networks involved in emotion generation and regulation, we found an increase in the functional integration of the emotional control network among older adults. Additionally, confirming through the nonlinear model, individuals around the age of 70 showed a steadier decline in integration of a network mediating emotion generation and regulation via interoception. Furthermore, the analyses revealed a negative association between age and perceived stress and loneliness that could be attributed to differences in large-scale emotion regulation networks. Our study highlights the importance of identifying topological changes in the functional emotion network architecture across the lifespan, as it allows for a better understanding of emotional aging and psychological well-being in late adulthood.

Effects of chronic intranasal oxytocin on visual attention to faces vs. natural scenes in older adults.

Aging is associated with changes in face processing, including desensitization to face cues like gaze direction and an attentional preference to faces with positive over negative emotional valence. A parallel line of research has shown that acute administration of oxytocin (OT) increases visual attention to social stimuli such as human faces. The current study examined effects of chronic OT administration among older adults on fixation duration to faces that varied in emotional expression, gaze direction, age, and sex. One hundred and twelve generally healthy older adults (aged 55-95 years) underwent a randomized, placebo-controlled, double-blind, between-subject clinical trial in which they self-administered either OT or placebo (P) intranasally twice a day for 4 weeks. The behavioral task involved rating the trustworthiness of faces (i.e., social stimuli) and natural scenes (i.e., non-social control stimuli) during eye tracking and was conducted before and after the intervention. Fixation duration to both the faces and the natural scenes declined from pre- to post-intervention, however this decline was less pronounced among older adults in the OT compared to the P group for faces but not scenes. Further, face cues (emotional expression, gaze direction, age, sex) did not moderate the treatment effect. This study provides first evidence that chronic intranasal OT maintains salience of social cues over time in older adults, perhaps buffering effects of habituation. These findings enhance understanding of OT effects on social cognition among older adults, and would benefit from follow up with a young adult comparison group to directly speak to specificity of observed effects to older adults and reflection of the aging process.

Relationship of Mean Platelet Volume (MPV) and Mean Corpuscular Volume (MCV) with the Outcome of Patients with Acute Exacerbation of COPD.

Background: Mean platelet volume (MPV) reflects the platelet production rate and stimulation, while mean corpuscular volume (MCV) represents the average size of red blood cells. Considering the possibility of the relationship between red cell index changes and different severities of chronic obstructive pulmonary disease (COPD) as well as the uncertainty of the available results in this regard, the present study aimed at evaluating the relationship between MPV and MCV in the outcome of patients with acute exacerbation of COPD (AECOPD). Materials and Methods: In this cross-sectional analytical study, 150 patients with AECOPD that referred to the emergency department (ED) were included in the study. The severity of the disease was recorded using the GOLD classification, and the MPV and the MCV were evaluated based on the reference range of kits in the laboratory. Then, the data were analyzed using SPSS software. Results: The mean MPV and MCV were 9.7±8.3 and 85.9±11.5, respectively, and had no significant difference in different severities of COPD(P>0.05). Moreover, although MCV in survivals with a mean of 88.81±6.47 was higher than that of non-survivals with a mean of 85.77±11.73, and MPV in the non-survivals with a mean of 8.53±9.74 was higher than that of survivals with the mean of 8.86±0.92, this difference was not statistically significant (P>0.05). Conclusion: Overall, the results of this study showed that the mean MPV and MCV did not have any significant relationship with AECOPD and patient outcome.

Diagnostic Value of the Optic Nerve Sheath in the Diagnosis of Increased Intracranial Pressure in Traumatic Brain Patients.

Background: Increased intracranial pressure (ICP) is a modifiable secondary injury that is associated with poor outcomes in patients with traumatic brain injuries (TBIs). Therefore, the present study was conducted with the aim of determining the ICP of TBI patients by measuring the thickness of the optic nerve sheath diameter (ONSD). Materials and Methods: The present cross-sectional study was conducted on 220 patients with severe TBI that referred to Khatam-al-Anbya Hospital in Zahedan in 2021. The measurement of ONSD was performed by ultrasonography. Results: The results of this study revealed that 22.7% of TBI patients had high ICP. The mean of right and left ONSD in patients with normal ICP was 3.85 ± 0.83 and 3.85 ± 0.82 mm, respectively, and was significantly lower than that of patients with abnormal ICP (high ICP) with the mean of 3.85 ± 0.82 and 6.12 ± 0.84 mm, respectively (P value <.001). In addition, the right ONSD with the cutoff point of 5.13 mm, the sensitivity of 84%, and the specificity of 95.29% and the left ONSD with the cutoff point of 5.24 mm, the sensitivity of 90%, and the specificity of 95.88% had a significant diagnostic value in the diagnosis of high ICP (P value <.05). Conclusion: The findings of the present study indicated that the measurement of ONSD is a cost-effective and minimally invasive procedure with a higher accuracy in diagnosing high ICP in TBI patients.

The Level of Serum Osmolarity at Admission in Prognosis of Nosocomial Mortality in Patients with Severe Brain Trauma.

Background: Traumatic brain injury (TBI) is a leading cause of death among patients in developed countries. The patients' prognosis depends on the trauma-induced primary damage as well as the secondary brain damage, including electrolyte disturbances. Therefore, prevention, diagnosis, and timely treatment lead to better prognosis. Herein, the aim is to prognosticate about the mortality in patients with TBI through serum osmolarity at admission. Materials and Methods: In this cross-sectional study, 141 patients with TBI were assigned through convenience sampling. The level of serum osmolarity was examined once the patients were admitted to emergency department and later, the outcome was recorded. Finally, we analyzed the relationship between osmolarity level and patient outcome in age groups. Results: The mean serum osmolarity in the age group of under 18 years, 18 to 60 years, and more than 60 years was equal to 295.3 ± 10.02 mOsm/L, 297.2 ± 6.5 mOsm/L, and 301.6 ± 7.6 mOsm/L, respectively (P-value <0.001). Osmolarity with a cut-off point of more than 298.90 and sensitivity and specificity of 70.49 and 62.86, respectively, had appropriate diagnostic value for predicting mortality in these patients (P-value <0.001). Conclusion: According to the results of this study, serum osmolarity can have an appropriate diagnostic value in predicting mortality in patients with TBI. In addition, in different age categories, the osmolarity serum in the mortality of these patients was significantly different. Therefore, due to the high importance of serum osmolarity in the mortality of patients, careful monitoring of fluid therapy status of trauma patients should be implemented to prevent the development of hyperosmolarity for the patient with irreversible outcomes.

Clinical, histological, and histomorphometrical comparison of CenoBone® with and without plasma rich in growth factor for edentulous ridge preservation in the dental sockets.

Background: The aim of this study was to compare the clinical, histological, and histomorphometrical outcomes of CenoBone® allograft with and without plasma rich in growth factor (PRGF) for the preservation of edentulous ridge in the dental sockets. Materials and Methods: This study is experimental clinical trial that 14 dental sockets were included the sockets required ridge preservation followed by implant placement in the premolar and molar of the mandible. After extraction of the teeth, the CenoBone® allograft and PRGF were used in the test group and CenoBone® allograft was used alone in the control group. During the first stage of surgery and 5 months later, in the second stage of surgery (implant placement), the vertical changes of the ridge were measured. Furthermore, using Core-Biopsy in the second stage of surgery, criteria of histologic and histomorphometric were determined. Data were analyzed with t-test, Mann-Whitney U-test, and Fisher's exact test at the level of significance of P < 0.05. Results: The mean trabecular thickness in the test group (52.18 ± 5.53) was significantly higher than that in the control group (41.53 ± 10.40) (P = 0.344). However, there were no significant differences in the mean values of vertical bone absorption, bone percentage, remaining biomaterials, inflammation, and blood vessels between the two groups. There was no case of foreign body reaction and the bone was vital in all the cases and in direct contact with the biomaterial. Conclusion: Although CenoBone® allograft with PRGF was effective in some histomorphometric factors such as trabecular thickness, it did not lead to significant clinical changes.

Effects of incorporating zinc oxide and graphene oxide nanoparticles on abrasion, translucency, and microhardness of flowable composite resin: In vitro.

Background: Zinc oxide (ZnO) and graphene oxide (GO) nanoparticles (NPs) have antimicrobial properties. The present study was undertaken to evaluate the effects of incorporating these NPs and their chemical and physical blends on abrasion, translucency, and microhardness of flowable composite resin. Materials and Methods: In the present in vitro study, flowable composite resin samples (Grandio Flow, VOCO, Germany) were evaluated in 5 groups and the sample size was 10 for each group of each experiment (n = 10) as follows: Group 1, without NPs; Group 2, with ZnO NPs; Group 3, with GO NPs; Group 4, containing a physical mixture of GO and ZnO; and Group 5, containing a chemical mixture of GO and ZnO NPs. In all the groups, 1 wt% of the NPs were incorporate into flowable composite resin. Abrasion, translucency, and microhardness of the samples were evaluated. Data were analyzed with analysis of variance, followed by post hoc Tukey's tests at the level of significance of P < 0.05. Results: In Groups 2, 4, and 5 (all the groups containing ZnO), a significant decrease in abrasion and microhardness of flowable composite resin was observed compared to the control group. Incorporation of NPs in all the groups resulted in a significant decrease in translucency compared to the control group. Conclusion: Incorporation of NPs into flowable composite resin resulted in a decrease in translucency. The microhardness was reduced in groups containing ZnO, but the abrasion was also reduced in these groups. The incorporation of GO did not significantly alter the abrasion and microhardness of the composite resin.

Social Cognition in Temporal and Frontal Lobe Epilepsy: Systematic Review, Meta-analysis, and Clinical Recommendations.

OBJECTIVE: Despite the importance of social cognitive functions to mental health and social adjustment, examination of these functions is absent in routine assessment of epilepsy patients. Thus, this review aims to provide a comprehensive overview of the literature on four major aspects of social cognition among temporal and frontal lobe epilepsy, which is a critical step toward designing new interventions. METHOD: Papers from 1990 to 2021 were reviewed and examined for inclusion in this study. After the deduplication process, a systematic review and meta-analysis of 44 and 40 articles, respectively, involving 113 people with frontal lobe epilepsy and 1482 people with temporal lobe epilepsy were conducted. RESULTS: Our results indicated that while patients with frontal or temporal lobe epilepsy have difficulties in all aspects of social cognition relative to nonclinical controls, the effect sizes were larger for theory of mind (g = .95), than for emotion recognition (g = .69) among temporal lobe epilepsy group. The frontal lobe epilepsy group exhibited significantly greater impairment in emotion recognition compared to temporal lobe. Additionally, people with right temporal lobe epilepsy (g =  1.10) performed more poorly than those with a left-sided (g = .90) seizure focus, specifically in the theory of mind domain. CONCLUSIONS: These data point to a potentially important difference in the severity of deficits within the emotion recognition and theory of mind abilities depending on the laterlization of seizure side. We also suggest a guide for the assessment of impairments in social cognition that can be integrated into multidisciplinary clinical evaluation for people with epilepsy.

Self-Punishment and Reward Backfill for Deep Q-Learning.

Reinforcement learning (RL) agents learn by encouraging behaviors, which maximizes their total reward, usually provided by the environment. In many environments, however, the reward is provided after a series of actions rather than each single action, leading the agent to experience ambiguity in terms of whether those actions are effective, an issue known as the credit assignment problem. In this brief, we propose two strategies inspired by behavioral psychology to enable the agent to intrinsically estimate more informative reward values for actions with no reward. The first strategy, called self-punishment (SP), discourages the agent from making mistakes that lead to undesirable terminal states. The second strategy, called the reward backfill (RB), backpropagates the rewards between two rewarded actions. We prove that, under certain assumptions and regardless of the RL algorithm used, these two strategies maintain the order of policies in the space of all possible policies in terms of their total reward and, by extension, maintain the optimal policy. Hence, our proposed strategies integrate with any RL algorithm that learns a value or action-value function through experience. We incorporated these two strategies into three popular deep RL approaches and evaluated the results on 30 Atari games. After parameter tuning, our results indicate that the proposed strategies improve the tested methods in over 65% of tested games by up to over 25 times performance improvement.

Temporal changes in personal activity intelligence and the risk of incident dementia and dementia related mortality: A prospective cohort study (HUNT).

Background: The Personal Activity Intelligence (PAI) translates heart rate during daily activity into a weekly score. Obtaining a weekly PAI score ≥100 is associated with reduced risk of premature morbidity and mortality from cardiovascular diseases. Here, we determined whether changes in PAI score are associated with changes in risk of incident dementia and dementia-related mortality. Methods: We conducted a prospective cohort study of 29,826 healthy individuals. Using data from the Trøndelag Health-Study (HUNT), PAI was estimated 10 years apart (HUNT1 1984-86 and HUNT2 1995-97). Adjusted hazard-ratios (aHR) and 95%-confidence intervals (CI) for incidence of and death from dementia were related to changes in PAI using Cox regression analyses. Findings: During a median follow-up time of 24.5 years (interquartile range [IQR]: 24.1-25.0) for dementia incidence and 23.6 years (IQR: 20.8-24.2) for dementia-related mortality, there were 1998 incident cases and 1033 dementia-related deaths. Individuals who increased their PAI score over time or maintained a high PAI score at both assessments had reduced risk of dementia incidence and dementia-related mortality. Compared with persistently inactive individuals (0 weekly PAI) at both time points, the aHRs for those with a PAI score ≥100 at both occasions were 0.75 (95% CI: 0.58-0.97) for incident dementia, and 0.62 (95% CI: 0.43-0.91) for dementia-related mortality. Using PAI score <100 at both assessments as the reference cohort, those who increased from <100 at HUNT1 to ≥100 at HUNT2 had aHR of 0.83 (95% CI: 0.72-0.96) for incident dementia, and gained 2.8 (95% CI: 1.3-4.2, P<0.0001) dementia-free years. For dementia-related mortality, the corresponding aHR was 0.74 (95% CI: 0.59-0.92) and years of life gained were 2.4 (95% CI: 1.0-3.8, P=0.001). Interpretation: Maintaining a high weekly PAI score and increases in PAI scores over time were associated with a reduced risk of incident dementia and dementia-related mortality. Our findings extend the scientific evidence regarding the protective role of PA for dementia prevention, and suggest that PAI may be a valuable tool in guiding research-based PA recommendations. Funding: The Norwegian Research Council, the Liaison Committee between the Central Norway Regional Health Authority and Norwegian University of Science and Technology (NTNU), Trondheim, Norway.

Age-Related Differences in Amygdala Activation Associated With Face Trustworthiness but No Evidence of Oxytocin Modulation.

The amygdala has been shown to be responsive to face trustworthiness. While older adults typically give higher face trustworthiness ratings than young adults, a direct link between amygdala response and age-related differences in face trustworthiness evaluation has not yet been confirmed. Additionally, there is a possible modulatory role of the neuropeptide oxytocin in face trustworthiness evaluation, but the results are mixed and effects unexplored in aging. To address these research gaps, young, and older adults were randomly assigned to oxytocin or placebo self-administration via a nasal spray before rating faces on trustworthiness while undergoing functional magnetic resonance imaging. There was no overall age-group difference in face trustworthiness ratings, but older compared to young participants gave higher trustworthiness ratings to ambivalently untrustworthy-looking faces. In both age groups, lower face trustworthiness ratings were associated with higher left amygdala activity. A comparable negative linear association was observed in right amygdala but only among young participants. Also, in the right amygdala, lower and higher, compared to moderate, face trustworthiness ratings were associated with greater right amygdala activity (i.e., positive quadratic (U-shaped) association) for both age groups. Neither the behavioral nor the brain effects were modulated by a single dose of intranasal oxytocin administration, however. These results suggest dampened response to faces with lower trustworthiness among older compared to young adults, supporting the notion of reduced sensitivity to cues of untrustworthiness in aging. The findings also extend evidence of an age-related positivity effect to the evaluation of face trustworthiness.

Neural activation during emotional interference corresponds to emotion dysregulation in stressed teachers.

Teacher stress and burnout has been associated with low job satisfaction, reduced emotional wellbeing, and poor student learning outcomes. Prolonged stress is associated with emotion dysregulation and has thus become a focus of stress interventions. This study examines emotional interference effects in a group of teachers suffering from high stress and to explore how individual differences in cognitive control, emotion dysregulation, and emotion recognition related to patterns of neural activation. Forty-nine teachers suffering moderate-high stress participated in an emotional counting Stroop task while their brain activity was imaged using functional magnetic resonance imaging. Participants viewed general or teacher specific words of either negative or neutral valence and were required to count the number of words on screen. Behavioural and neuroimaging results suggest that teachers are able to control emotional responses to negative stimuli, as no evidence of emotional interference was detected. However, patterns of neural activation revealed early shared engagement of regions involved in cognitive reappraisal during negative task conditions and unique late engagement of the hippocampus only while counting teacher-specific negative words. Further, we identified that greater emotion dysregulation was associated with increased activation of regions involved in cognitive control processes during neutral word trials. Teachers who showed slower emotion recognition performance were also found to have greater activation in regions associated with visual and word processing, specifically during the teacher specific negative word condition of the task. Future research should explore emotion regulation strategy use in teachers and utilise temporally sensitive neuroimaging techniques to further understand these findings.

Teacher stress and burnout in Australia: examining the role of intrapersonal and environmental factors.

Concerns regarding high rates of teacher stress and burnout are present globally. Yet there is limited current data regarding the severity of stress, or the role of intrapersonal and environmental factors in relation to teacher stress and burnout within the Australian context. The present study, conducted over an 18-month period, prior to the COVID pandemic, surveyed 749 Australian teachers to explore their experience of work-related stress and burnout; differences in stress and burnout across different demographic groups within the profession; as well as the contributing role of intrapersonal and environmental factors, particularly, emotion regulation, subjective well-being, and workload. Results showed over half of the sample reported being very or extremely stressed and were considering leaving the profession, with early career teachers, primary teachers, and teachers working in rural and remote areas reporting the highest stress and burnout levels. Conditional process analyses highlighted the importance of emotion regulation, workload and subjective well-being in the development of teacher stress and some forms of burnout. Implications for educational practice are discussed.

Neural correlates of affective empathy in aging: A multimodal imaging and multivariate approach.

Empathy is one such social-cognitive capacity that undergoes age-related change. C urrently, however, not well understood is the structural and functional neurocircuitry underlying age-related differences in empathy. This study aimed to delineate brain structural and functional networks that subserve affective empathic response in younger and older adults using a modified version of the Multifaceted Empathy Task to both positive and negative emotions. Combining multimodal neuroimaging with multivariate partial least square analysis resulted in two novel findings in older but not younger adults: (a) faster empathic responding to negative emotions was related to greater fractional anisotropy of the anterior cingulum and greater functional activity of the anterior cingulate network; (b) however, empathic responding to positive emotions was related to greater fractional anisotropy of the posterior cingulum and greater functional activity of the posterior cingulate network. Such differentiation of structural and functional networks might have critical implications for prosocial behavior and social connections among older adults.

Can exercise training teach us how to treat Alzheimer's disease?

Alzheimer's disease (AD) is the most common cause of dementia and there is currently no cure. Novel approaches to treat AD and curb the rapidly increasing worldwide prevalence and costs of dementia are needed. Physical inactivity is a significant modifiable risk factor for AD, estimated to contribute to 12.7% of AD cases worldwide. Exercise interventions in humans and animals have shown beneficial effects of exercise on brain plasticity and cognitive functions. In animal studies, exercise also improved AD pathology. The mechanisms underlying these effects of exercise seem to be associated mainly with exercise performance or cardiorespiratory fitness. In addition, exercise-induced molecules of peripheral origin seem to play an important role. Since exercise affects the whole body, there likely is no single therapeutic target that could mimic all the benefits of exercise. However, systemic strategies may be a viable means to convey broad therapeutic effects in AD patients. Here, we review the potential of physical activity and exercise training in AD prevention and treatment, shining light on recently discovered underlying mechanisms and concluding with a view on future development of exercise-free treatment strategies for AD.

In silico evaluation of the downstream effect of mutated glucagon is consistent with higher blood glucose homeostasis in Galliformes and Strigiformes.

In contrast to mammals, glucagon is reported as a much more potent blood glucose modulator in birds. Interestingly, we have found p.Thr16Ser mutation, a variation in the highly conserved glucagon hormone, in Galliformes as well as Strigiformes. To check the effect of this mutation on the receptor binding of glucagon, we predicted the ancestral glucagon receptor sequence of all available Galliformes and Strigiformes species. Subsequently, we analysed their binding to the mutated and wild type glucagon (ancestral) by molecular dynamics simulation. At first, we made a model of ancestral glucagon receptor and ancestral mutated, and wild type glucagon in the order Galliformes and Strigiformes. Then we performed molecular dynamics for each Galliformes and Strigiformes receptor as well as each glucagon peptide, respectively. The final structures were used for docking simulation of glucagon to their receptors. The results of the docking simulations showed a stronger binding affinity of mutated glucagon to glucagon receptors. Afterward, we obtained blood glucose concentrations of all available Galliformes members, as well as all available members of its only taxonomic neighbour (order Anseriformes) in superorder Galloanserae. Interestingly the p.Thr16Ser mutation could finely cluster these two orders into two groups: higher blood glucose concentration (order Galliformes, 17.64 ± 1.66 mMol/L) and lower blood glucose concentration (order Anseriformes, 11.34 ± 1.11 mMol/L). Strigiformes which carry the mutated glucagon peptide show also high blood glucose concentrations (17.40 ± 1.51 mMol/L). Therefore, the results suggest this mutation, which leads to stronger binding affinity of mutated glucagon to its receptor, may be a driving force for higher blood glucose homeostasis in the related birds.

The Downstream Effects of Teacher Well-Being Programs: Improvements in Teachers' Stress, Cognition and Well-Being Benefit Their Students.

Quality interventions addressing the important issue of teacher stress and burnout have shown promising outcomes for participating teachers in terms of decreased distress, improved well-being and increased commitment to their jobs. Less is known however about whether such interventions also benefit students. The present study investigated the downstream effects for a completer sample of 226 primary and high school students after their teachers (n = 17) completed one of two 8-week stress reduction interventions. The relationships between change in teacher self-reported distress and burnout after completing the interventions, and change in students' self-reported well-being, academic self-perceptions, and perceptions of classroom environment were explored. A secondary aim of this study was to assess whether changes in teachers' cognitive flexibility mediated the relationship between teacher and student self-report outcomes. Results of correlational and multi-level mediation analyses showed that changes to teachers' self-reported distress and burnout affected multiple facets of students' well-being and the academic environment. Specifically, reductions in teachers' self-reported distress and burnout were related to students' improved perceptions of their teachers' support in the classroom. Reductions in teachers' personal and work-related burnout correlated with greater increases of academic self-perception in students. Contrary to predictions, cognitive flexibility in teachers did not mediate the relationship between these student and teacher measures. These findings indicate important downstream benefits for students and highlight the broader value of stress-reduction and well-being programs for teachers.

Age-related differences in negative cognitive empathy but similarities in positive affective empathy.

Empathy, among other social-cognitive processes, changes across adulthood. More specifically, cognitive components of empathy (understanding another's perspective) appear to decline with age, while findings for affective empathy (sharing another's emotional state) are rather mixed. Structural and functional correlates underlying cognitive and affective empathy in aging and the extent to which valence affects empathic response in brain and behavior are not well understood yet. To fill these research gaps, younger and older adults completed a modified version of the Multifaceted Empathy Test, which measures both cognitive and affective empathy as well as empathic responding to both positive and negative stimuli (i.e., positive vs. negative empathy). Adopting a multimodal imaging approach and applying multivariate analysis, the study found that for cognitive empathy to negative emotions, regions of the salience network including the anterior insula and anterior cingulate were more involved in older than younger adults. For affective empathy to positive emotions, in contrast, younger and older adults recruited a similar brain network including main nodes of the default mode network. Additionally, increased structural microstructure (fractional anisotropy values) of the posterior cingulum bundle (right henisphere) was related to activation of default mode regions during affective empathy for positive emotions in both age groups. These findings provide novel insights into the functional networks subserving cognitive and affective empathy in younger and older adults and highlight the importance of considering valence in empathic response in aging research. Further this study, for the first time, underscores the role of the posterior cingulum bundle in higher-order social-cognitive processes such as empathy, specifically for positive emotions, in aging.

Age-related Differences in Expression Recognition of Faces with Direct and Averted Gaze Using Dynamic Stimuli.

Background: It is still an open to what extent the ecological validity of face stimuli modulates age-related differences in the recognition of facial expression; and to what extent eye gaze direction may play a role in this process. The present study tested whether age effects in facial expression recognition, also as a function of eye gaze direction, would be less pronounced in dynamic than static face displays.Method: Healthy younger and older adults were asked to recognize emotional expressions of faces with direct or averted eye gaze presented in static and dynamic format.Results: While there were no differences between the age groups in facial expression recognition ability across emotions, when considering individual expressions, age-related differences in the recognition of angry facial expressions were attenuated for dynamic compared to static stimuli.Conclusion: Our findings suggest a moderation effect of dynamic vs. static stimulus format on age-related deficits in the identification of angry facial expressions, suggesting that older adults may be less disadvantaged when recognizing angry facial expressions in more naturalistic displays. Eye gaze direction did not further modulate this effect. Findings from this study qualify and extend previous research and theory on age-related differences in facial expression recognition and have practical impact on study design by supporting the use of dynamic faces in aging research.

Age-related differences in structural and functional prefrontal networks during a logical reasoning task.

In logical reasoning, difficulties in inhibition of currently-held beliefs may lead to unwarranted conclusions, known as belief bias. Aging is associated with difficulties in inhibitory control, which may lead to deficits in inhibition of currently-held beliefs. No study to date, however, has investigated the underlying neural substrates of age-related differences in logical reasoning and the impact of belief load. The aim of the present study was to delineate age differences in brain activity during a syllogistic logical reasoning task while the believability load of logical inferences was manipulated. Twenty-nine, healthy, younger and thirty, healthy, older adults (males and females) completed a functional magnetic resonance imaging experiment in which they were asked to determine the logical validity of conclusions. Unlike younger adults, older adults engaged a large-scale network including anterior cingulate cortex and inferior frontal gyrus during conclusion stage. Our functional connectivity results suggest that while older adults engaged the anterior cingulate network to overcome their intuitive responses for believable inferences, the inferior frontal gyrus network contributed to higher control over responses during both believable and unbelievable conditions. Our functional results were further supported by structure-function-behavior analyses indicating the importance of cingulum bundle and uncinate fasciculus integrity in rejection of believable statements. These novel findings lend evidence for age-related differences in belief bias, with potentially important implications for decision making where currently-held beliefs and given assumptions are in conflict.