Brain Processing of Emotional Scenes in Aging: Effect of Arousal and Affective Context

Abstract

Research on emotion showed an increase, with age, in prevalence of positive information relative to negative ones. This effect is called positivity effect. From the cerebral analysis of the Late Positive Potential (LPP), sensitive to attention, our study investigated to which extent the arousal level of negative scenes is differently processed between young and older adults and, to which extent the arousal level of negative scenes, depending on its value, may contextually modulate the cerebral processing of positive (and neutral) scenes and favor the observation of a positivity effect with age. With this aim, two negative scene groups characterized by two distinct arousal levels (high and low) were displayed into two separate experimental blocks in which were included positive and neutral pictures. The two blocks only differed by their negative pictures across participants, as to create two negative global contexts for the processing of the positive and neutral pictures. The results show that the relative processing of different arousal levels of negative stimuli, reflected by LPP, appears similar between the two age groups. However, a lower activity for negative stimuli is observed with the older group for both tested arousal levels. The processing of positive information seems to be preserved with age and is also not contextually impacted by negative stimuli in both younger and older adults. For neutral stimuli, a significantly reduced activity is observed for older adults in the contextual block of low-arousal negative stimuli. Globally, our study reveals that the positivity effect is mainly due to a modulation, with age, in processing of negative stimuli, regardless of their arousal level. It also suggests that processing of neutral stimuli may be modulated with age, depending on negative context in which they are presented to. These age-related effects could contribute to justify the differences in emotional preference with age.

The Last Word: A Comparison of Younger and Older Adults’ Brain Responses to Reminders of Death

“…Because the effect size of the age group by word type interaction was relatively small ( η p 2 = .08) and because we were primarily interested in differences in processing of death-related and negative words, we reran the analysis without positive emotion words. This contrast was also in line with the focus on age-related differences in negative words in previous LPP research (e.g., Kisley et al, 2007;Mathieu et al, 2014). This comparison results in a significantly larger effect size ( η p 2 = .16), supporting the idea that there are significant differences in processing of death-related words.…”

Modulation of Prepulse Inhibition and Startle Reflex by Emotions: A Comparison between Young and Older Adults

“…Both sensorimotor gating and emotional processing seem to be well preserved in aging, as shown by similar levels of PPI in the no-image condition in young and older adults, and a strong effect of emotion regulation by the prepulse. Older adults have a bias towards positive emotional stimuli and decreased processing of negative emotional stimuli (the positivity effect, Mather and Carstensen, 2005 ), they remember more positive than negative information than young people (Charles et al, 2003 ) and display reduced late positive potential (LPP) amplitude for negative stimuli (Mathieu et al, 2014 ). When free to look at positive, neutral, or negative pictures, a higher proportion of pictures remembered by older adults consisted of positive than negative information compared with the younger adults.…”

Cerebral Correlates of Emotional and Action Appraisals During Visual Processing of Emotional Scenes Depending on Spatial Frequency: A Pilot Study

“…Stimuli were selected from an in-house database created for, and used in, a previous study [ 1 ] (stimuli pretested on 108 subjects [ 1 , 6 ]), and were characterized by emotional valence, arousal level and tendency to action. Unpleasant stimuli (-6.43 ± 1.42; on a valence scale from 10-pleasant to -10-unpleasant with 0- absence of or weak valence) induced an arousal level of 5.51 (± 0.93; on a scale from 1-low arousal to 10-high arousal) and a tendency to avoid (-7.27 ± 1.18; on an action tendency scale from 10-approach to -10-avoid with 0- absence of or weak tendency to action).…”

“…Stimuli used in the localizer experiment were different from the main experiment and included black and white photographs of 52 natural scenes and 52 facial expressions selected from a home database (partially published, [ 6 ]) and the KDEF database (Karolinska Directed Emotional Face set: [ 76 ]). Half of the scenes and faces were unpleasant (scenes: -6.41 ± 1.33; faces: 5.59 ± 1.02 on a scale from 10-pleasant to -10-unplesant with 0-absence of or weak valence) and induced high arousal levels (scenes: 5.68 ± 0.93; faces: 3.62 ± 0.99 on a scale from 1-low arousal to 10-high arousal), the other half was judged neutral (scenes: 0.35 ± 1.26; faces: 0.75 ± 0.58) and induced low arousal levels (scenes: 0.02 ±1.01; faces: 1.57 ± 0.35).…”