Nathalie Mella

How emotional auditory stimuli modulate time perception

Emotional and neutral sounds rated for valence and arousal were used to investigate the influence of emotions on timing in reproduction and verbal estimation tasks with durations from 2 s to 6 s. Results revealed an effect of emotion on temporal judgment, with emotional stimuli judged to be longer than neutral ones for a similar arousal level. Within scalar expectancy theory (J. Gibbon, R. Church, & W. Meck, 1984), this suggests that emotion-induced activation generates an increase in pacemaker rate, leading to a longer perceived duration. A further exploration of self-assessed emotional dimensions showed an effect of valence and arousal. Negative sounds were judged to be longer than positive ones, indicating that negative stimuli generate a greater increase of activation. High-arousing stimuli were perceived to be shorter than low-arousing ones. Consistent with attentional models of timing, this seems to reflect a decrease of attention devoted to time, leading to a shorter perceived duration. These effects, robust across the 2 tasks, are limited to short intervals and overall suggest that both activation and attentional processes modulate the timing of emotional events.

The role of physiological arousal in time perception: Psychophysiological evidence from an emotion regulation paradigm

Time perception, crucial for adaptive behavior, has been shown to be altered by emotion. An arousal-dependent mechanism is proposed to account for such an effect. Yet, physiological measure of arousal related with emotional timing is still lacking. We addressed this question using skin conductance response (SCR) in an emotion regulation paradigm. Nineteen participants estimated durations of neutral and negative sounds by comparing them to a previously memorized duration. Instructions were given to attend either to temporal or to emotional stimulus features. Attending to emotion with negative sounds generated longer subjective duration and greater physiological arousal than attending to time. However, a shared-attention condition showed discrepancy between behavioral and physiological results. Supporting the idea of a link between autonomic arousal and subjective duration, our results however suggest that this relation is not as direct as was expected. Results are discussed within recent model linking time perception, emotion and awareness.

Empathy for Pain from Adolescence through Adulthood: An Event-Related Brain Potential Study

Affective and cognitive empathy are traditionally differentiated, the affective component being concerned with resonating with another’s emotional state, whereas the cognitive component reflects regulation of the resulting distress and understanding of another’s mental states (see Decety and Jackson, 2004 for a review). Adolescence is a critical period for the development of cognitive control processes necessary to regulate affective processes: it is only in young adulthood that these control processes achieve maturity (Steinberg, 2005). Thus, one should expect adolescents to show greater automatic empathy than young adults. The present study aimed at exploring the neural correlates of affective (automatic) and cognitive empathy for pain from adolescence to young adulthood. With this aim, Event Related Potentials (ERPs) were recorded in 32 participants (aged 11–39) in a task designed to dissociate these components. ERPs results showed an early automatic fronto-central response to pain (that was not modulated by task demand) and a late parietal response to painful stimuli modulated by attention to pain cues. Adolescents exhibited earlier automatic responses to painful situations than young adults did and showed greater activity in the late cognitive component even when viewing neutral stimuli. Results are discussed in the context of the development of regulatory abilities during adolescence.

Subjectivity of time perception: a visual emotional orchestration

The aim of the present study was to examine how visual emotional content could orchestrate time perception. The experimental design allowed us to single out the share of emotion in the specific processing of content-bearing pictures, i.e., real-life scenes. Two groups of participants had to reproduce the duration (2, 4, or 6 s) of content-deprived stimuli (gray squares) or differentially valenced content-bearing stimuli, which included neutral, pleasant, and unpleasant pictures (International Affective Pictures Systems). Results showed that the effect of content differed according to duration: at 2 s, the reproduced duration was longer for content-bearing than content-deprived stimuli, but the difference between the two types of stimuli decreased as duration increased and was not significant for the longest duration (6 s). At 4 s, emotional (pleasant and unpleasant) stimuli were judged longer than neutral pictures. Furthermore, whatever the duration, the precision of the reproduction was greater for non-emotional than emotional stimuli (pleasant and unpleasant). These results suggest a dissociation within content effect on timing in the visual modality: relative overestimation of all content-bearing pictures limited to short durations (2 s), and delayed overestimation of emotional relative to neutral pictures at 4 s, as well as a lesser precision in the temporal judgment of emotional pictures whatever the duration. Our results underline the relevance for time perception models to integrate two ways of assessing timing in relationship with emotion: accuracy and precision.

Dispersion in cognitive functioning: Age differences over the lifespan

ABSTRACT Introduction: A growing body of research suggests that intraindividual variability (IIV) may bring specific information on cognitive functioning, additional to that provided by the mean. The present paper focuses on dispersion, that is IIV across tasks, and its developmental trend across the lifespan. Method: A total of 557 participants (9–89 years) were administered a battery of response time (RT) tasks and of working memory (WM) tasks. Dispersion was analyzed separately for the two types of tasks. Results: Dispersion across RT tasks showed a U-shaped age differences trend, young adults being less variable than both children and older adults. Dispersion across WM tasks (using accuracy scores) presented an opposite developmental trend. A cluster analysis revealed a group of individuals showing relatively little dispersion and good overall performance (faster in RTs and better in WM), contrasted with a group of individuals showing a large dispersion in the RT tasks as well as poorer overall performance. All young adults were grouped in the first cluster; children and older adults were distributed in both clusters. Conclusion: It is concluded that (a) across-task IIV is relatively large in the entire sample and should not be neglected, (b) children and older adults show a larger dispersion than young adults, but only as far as the RT tasks are concerned, (c) variability in RTs and variability in WM performance do not reflect the same phenomenon.

Cognitive Intraindividual Variability and White Matter Integrity in Aging

The intraindividual variability (IIV) of cognitive performance has been shown to increase with aging. While brain research has generally focused on mean performance, little is known about neural correlates of cognitive IIV. Nevertheless, some studies suggest that IIV relates more strongly than mean level of performance to the quality of white matter (WM). Our study aims to explore the relation between WM integrity and cognitive IIV by combining functional (fMRI) and structural (diffusion tensor imaging, DTI) imaging. Twelve young adults (aged 18–30 years) and thirteen older adults (61–82 years) underwent a battery of neuropsychological tasks, along with fMRI and DTI imaging. Their behavioral data were analyzed and correlated with the imaging data at WM regions of interest defined on the basis of (1) the fMRI-activated areas and (2) the Johns Hopkins University (JHU) WM tractography atlas. For both methods, fractional anisotropy, along with the mean, radial, and axial diffusivity parameters, was computed. In accord with previous studies, our results showed that the DTI parameters were more related to IIV than to mean performance. Results also indicated that age differences in the DTI parameters were more pronounced in the regions activated primarily by young adults during a choice reaction-time task than in those also activated in older adults.

Leisure Activities and Change in Cognitive Stability: A Multivariate Approach

Aging is traditionally associated with cognitive decline, attested by slower reaction times and poorer performance in various cognitive tasks, but also by an increase in intraindividual variability (IIV) in cognitive performance. Results concerning how lifestyle activities protect from cognitive decline are mixed in the literature and all focused on how it affects mean performance. However, IIV has been proven to be an index more sensitive to age differences, and very little is known about the relationships between lifestyle activities and change in IIV in aging. This longitudinal study explores the association between frequency of physical, social, intellectual, artistic, or cultural activities and age-related change in various cognitive abilities, considering both mean performance and IIV. Ninety-six participants, aged 64–93 years, underwent a battery of cognitive tasks at four measurements over a seven-year period, and filled out a lifestyle activity questionnaire. Linear multilevel models were used to analyze the associations between change in cognitive performance and five types of activities. Results showed that the practice of leisure activities was more strongly associated with IIV than with mean performance, both when considering overall level and change in performance. Relationships with IIV were dependent of the cognitive tasks considered and overall results showed protective effects of cultural, physical and intellectual activities on IIV. These results underline the need for considering IIV in the study of age-related cognitive change.

Intra-Individual Variability from a Lifespan Perspective: A Comparison of Latency and Accuracy Measures

Within-task variability across trials (intra-individual variability (IIV)) has been mainly studied using latency measures but rarely with accuracy measures. The aim of the Geneva Variability Study was to examine IIV in both latency and accuracy measures of cognitive performance across the lifespan, administering the same tasks to children, younger adults, and older adults. Six processing speed tasks (Response Time (RT) tasks, 8 conditions) and two working memory tasks scored in terms of the number of correct responses (Working Memory (WM)—verbal and visuo-spatial, 6 conditions), as well as control tasks, were administered to over 500 individuals distributed across the three age periods. The main questions were whether age differences in IIV would vary throughout the lifespan according (i) to the type of measure used (RTs vs. accuracy); and (ii) to task complexity. The objective of this paper was to present the general experimental design and to provide an essentially descriptive picture of the results. For all experimental tasks, IIV was estimated using intra-individual standard deviation (iSDr), controlling for the individual level (mean) of performance and for potential practice effects. As concerns RTs, and in conformity with a majority of the literature, younger adults were less variable than both children and older adults, and the young children were often the most variable. In contrast, IIV in the WM accuracy scores pointed to different age trends—age effects were either not observed or, when found, they indicated that younger adults were the more variable group. Overall, the findings suggest that IIV provides complementary information to that based on a mean performance, and that the relation of IIV to cognitive development depends on the type of measure used.

Electrophysiological evidence for an accumulation process in the timing of emotional stimuli

Emotion and time perception are in constant interaction in everyday life activities. While growing literature explored the mechanisms underlying emotional timing, the neural correlates remain unknown. The present experiment explored evoked-related potentials associated to the estimation of emotional sounds duration and to its modulation by attention. Electroencephalographic activity and skin conductance response were recorded during a time estimation task, in which participants were instructed to attend either to time or to emotion. Attending to emotion increased autonomic arousal and lengthened subjective duration of stimuli. Conversely, focusing attention away from emotion decreased physiological arousal and shortened time estimates. ERP results showed that subjective time dilation was associated to enhanced amplitude of the Contingent Negative Variation - a slow negative wave involved in time processing. This result supports models of time perception assuming that subjective time is based on an accumulation process in the brain.

Cross-lagged relation of leisure activity participation to trail making test performance 6 years later: Differential patterns in old age and very old age.

Objective: We investigated cross-lagged relations between leisure activity participation and Trail Making Test (TMT) performance over 6 years and whether those reciprocal associations differed between individuals. Method: We analyzed data from 232 participants tested on performance in TMT Parts A and B as well as interviewed on leisure activity participation in 2 waves 6 years apart. Mean age in the Wave 1 was 73.42 years. Participants were also tested on vocabulary (Mill Hill scale) as a proxy indicator of crystallized intelligence and reported information on early and midlife cognitive reserve markers (education and occupation). Latent cross-lagged models were applied to investigate potential reciprocal activity−TMT relationships. Results: The relation of leisure activity participation predicting TMT performance 6 years later was significantly larger than was the relation of TMT performance predicting later leisure activity participation. Statistically comparing different moderator groups revealed that this pattern was evident both in individuals with low education and in those with high education but, notably, emerged in only young-old adults (but not in old-old adults), in individuals with a low cognitive level of job in midlife (but not in those with a high cognitive level of job in midlife), and in individuals with high scores in vocabulary (but not in those with low scores in vocabulary). Conclusions: Late-life leisure activity participation may predict later cognitive status in terms of TMT performance, but individuals may markedly differ with respect to such effects. Implications for current cognitive reserve and neuropsychological aging research are discussed.