cortex activity than younger adults while engaging in emotion-processing tasks, we argue that the cognitive control hypothesis is a more likely explanation for older adults' positivity effect than the aging-brain model. Copyright © 2011 S. Karger AG, Basel In contrast with the age-related declines in many domains of cognitive functioning [1] , emotion regulation functioning improves somewhat with age [2] . People experience less negative affect as they get older and can restore their good mood after being induced into a negative mood more effectively than younger adults [3] . Older adults also show a 'positivity effect' in attention and memory [4] . For instance, older adults sometimes spend a larger proportion of time viewing positive items and a smaller proportion viewing negative items than do younger adults [5,6] . Moreover, in some studies, compared with younger adults, less of what older adults remember is negative and more is positive [5,7,8] . Such age by valence interactions tend to have a medium effect size [8] ; thus, as might be expected, studies with relatively small participant groups do not always reveal significant age differences. Other factors, such as a level of arousal of stimuli [9] , availability of cognitive resources [6] or types of measurements across studies [10] , may also account for the presence or absence of a positivity effect.Why do older adults show some improvements in emotion regulation despite suffering age-related cogni- Key WordsEmotion ؒ Aging ؒ Functional magnetic resonance imaging ؒ Positivity effect ؒ Amygdala ؒ Prefrontal cortex Abstract Despite the fact that physical health and cognitive abilities decline with aging, the ability to regulate emotion remains stable and in some aspects improves across the adult life span. Older adults also show a positivity effect in their attention and memory, with diminished processing of negative stimuli relative to positive stimuli compared with younger adults. The current paper reviews functional magnetic resonance imaging studies investigating age-related differences in emotional processing and discusses how this evidence relates to two opposing theoretical accounts of older adults' positivity effect. The aging-brain model [Cacioppo et al. in: Social Neuroscience: Toward Understanding the Underpinnings of the Social Mind. New York, Oxford University Press, 2011] proposes that older adults' positivity effect is a consequence of age-related decline in the amygdala, whereas the cognitive control hypothesis [Kryla-Lighthall and Mather in: Handbook of Theories of Aging, ed 2. New York, Springer, 2009; Mather and Carstensen: Trends Cogn Sci 2005; 9: 496-502; Mather and Knight: Psychol Aging 2005; 20: 554-570] argues that the positivity effect is a result of older adults' greater focus on regulating emotion. Based on evidence for structural and functional preservation of the amygdala in older adults and findings that older adults show greater prefrontal

An emerging field of research focused on fluctuations in brain signals has provided evidence that the complexity of those signals, as measured by entropy, conveys important information about network dynamics (e.g., local and distributed processing). While much research has focused on how neural complexity differs in populations with different age groups or clinical disorders, substantially less research has focused on the basic understanding of neural complexity in populations with young and healthy brain states. The present study used resting-state fMRI data from the Human Connectome Project (Van Essen et al., 2013) to test the extent that neural complexity in the BOLD signal, as measured by multiscale entropy (1) would differ from random noise, (2) would differ between four major resting-state networks previously associated with higher-order cognition, and (3) would be associated with the strength and extent of functional connectivity—a complementary method of estimating information processing. We found that complexity in the BOLD signal exhibited different patterns of complexity from white, pink, and red noise and that neural complexity was differentially expressed between resting-state networks, including the default mode, cingulo-opercular, left and right frontoparietal networks. Lastly, neural complexity across all networks was negatively associated with functional connectivity at fine scales, but was positively associated with functional connectivity at coarse scales. The present study is the first to characterize neural complexity in BOLD signals at a high temporal resolution and across different networks and might help clarify the inconsistencies between neural complexity and functional connectivity, thus informing the mechanisms underlying neural complexity.

A number of recent studies have shown that associative memory for within-item features is enhanced for emotionally arousing items, whereas arousal-enhanced binding is not seen for associations between distinct items (for a review see Mather, 2007). The costs and benefits of arousal in memory binding have been examined for younger adults but not for older adults. The present experiment examined whether arousal would enhance younger and older adults' withinitem and between-item memory binding. The results revealed that arousal improved younger adults' within-item memory binding but not that of older adults. Arousal worsened both groups' between-item memory binding.Memory binding is an essential component of episodic memory; it allows people to remember a combination of features of an object, a person, or an event. For example, if you witness a car accident, your ability to bind disparate elements of an event together will determine whether you remember which driver was in each car. How does having an emotionally arousing component as part of an event affect memory binding? Recent laboratory studies indicate that the emotional arousal elicited by a stimulus item (such as a picture or word) can either enhance or impair later memory for the features or context associated with that item. For instance, a number of studies have found that memory for the color or location of emotional items is better than memory for the color or location of neutral items (Doerksen

Although cognition, to a large extent, was a common predictor of both types of game learning, regional white matter FA could separately predict action and strategy game learning. Given the neural and cognitive correlates of strategy game learning, strategy games may provide a more beneficial training tool for adults suffering from memory-related disorders or declines in processing speed, particularly older adults.