Healthy aging is associated with increased neural processing of positive valence but attenuated processing of emotional arousal: an fMRI study

Abstract

Arousal and valence play key roles in emotional perception, with normal aging leading to changes in the neural substrates supporting valence processing. The objective of this study was to investigate normal age-related changes in the neural substrates of emotional arousal processing. Twenty-three young and 23 older, healthy women underwent functional magnetic resonance imaging as they viewed images which were neutral or positive in valence and which varied in arousal level from low to high. Using a parametric modulation approach, we examined how the blood oxygen-level dependent signal varied with single trial subjective ratings of valence and arousal, and whether this differed with age. In accordance with previous studies we found that the older group showed greater activation in response to positive valence, in the left amygdala, left middle temporal gyrus and right lingual gyrus. In contrast however, they showed reduced reactivity to emotional arousal, in occipital and temporal visual cortices bilaterally, the left inferior parietal cortex, and the supplementary motor area bilaterally. This study represents the first of its kind to clearly dissociate how aging affects the neural correlates of emotional arousal and valence. The changes in arousal processing may in part be mediated by the functional reorganization evident in the aging brain, such as reduced activation of the posterior cortices as described by the posterior-anterior shift in ageing (PASA) effect.

Dissociable meta‐analytic brain networks contribute to coordinated emotional processing

“…This metaanalytic network of regions has been implicated in basic visual processing, participating in visual memory (Todd, Won Han, Harrison, & Marois, 2011), as well as recognition and naming of words (Price et al, 1994; Bookheimer, Zeffiro, Blaxton, Gaillard, & Theodore, 1995; Mechelli, Humphreys, Mayall, Olson, & Price, 2000). The involvement of the visual perception network in emotion is well documented (Keightley et al, 2003; Kehoe, Toomey, Balsters, & Bokde, 2013; Isenberg et al, 1999), and has been discussed in several meta-analyses (Kober et al, 2008; Fusar-Poli et al, 2009; Vytal & Hamann 2010). Furthermore, neuroimaging evidence has suggested that activation in the visual cortices may be modulated by affective stimuli (Vuilleumier & Pourtois, 2007; Stolarova, Keil, & Moratti, 2006) or by differential eye fixation strategies when perceiving affect-laden stimuli (van Reekum et al, 2007).…”

The Affective Neuroscience of Aging

“…Furthermore, it is relatively more responsive to positive than negative stimuli in older adults compared with younger adults (Erk et al, 2008, Ge et al, 2014, Kehoe et al, 2013, Leclerc and Kensinger, 2011, Mather et al, 2004, Waldinger et al, 2011, but see Moriguchi et al, 2011 for no age-by-valence effects in amygdala). Thus, the amygdala does not stop responding to emotional stimuli in later life, but instead, shifts which valence it is most responsive to.…”

Affective Norms for Italian Words in Older Adults: Age Differences in Ratings of Valence, Arousal and Dominance

“…In particular, a study by Kehoe and colleagues [57] found that older adults showed greater activation in the left amygdala, left middle temporal gyrus and right lingual gyrus in response to positive valence while, on the contrary, they showed reduced reactivity to emotional arousal, in occipital and temporal visual cortices, the left inferior parietal cortex and in bilateral supplementary motor areas.…”