Cognitive and affective neuroscience of aging

Chair:  Michael Falkenstein

Leibniz Research Centre for Working Environment and Human Factors( IfADo),
Dortmund, Germany


Abstract:

The symposium provides examples of studies on cognitive and emotional changes
in healthy older compared to young adults, and their assessment with the principal
neuroscience methods, fMRI and EEG/ERP. Special emphasis will be laid on
differences among high- and low-performing older people and how they are
reflected in brain activity.
Monicque Lorist will present a study on changes of memory and attention due to
ageing with both fMRI and ERP methodology. Lucie Angel will focus on the age-
related hemispheric asymmetry reduction known from fMRI studies with ERP
methodology in the context of an episodic memory task. Ben Godde will address
the issue of reduced negative affect in older subjects with fMRI methods, and the
reduction of this bias after physical fitness training.
Dick Jennings will report on the impact of blood pressure and hypertension on
affective and cognitive processing in older subjects. Finally Stephan Getzmann will
present data concerning speech processing in old vs. young subjects under
difficult listening conditions, using ERP methodology.

Talk 1:

Dynamics in cognitive ageing

Monicque M. Lorist & L. Geerligs
Department of Experimental Psychology, University of Groningen, Groningen, The Netherlands
BCN-Neuroimaging Center, University of Groningen, Groningen, The Netherlands

While some people age gracefully and are able to achieve levels of performance
comparable to young adults, others show cognitive decline with increasing age. A
pressing challenge is to understand the various ways in which aging affects
cognitive performance and which mechanisms underlie the individual differences in
age-related changes on cognition. In different projects, we examine these
dynamics in cognitive functioning in young and older individuals. Even though all
participants were healthy and functioned adequately in daily life, we found large
differences between individuals on both performance and brain activity measured
in working memory and attention tasks. Using functional connectivity analyses and
event related potentials we showed that especially high performing elderly use
more cognitive control to achieve similar performance to high performing younger
participants. This shows that some of the older participants seemed to be able to
effectively compensate for their age related decline. An additional question
addressed in our studies followed from the knowledge that ageing is accompanied
by general changes in brain structure and neuronal activity. These changes might
directly affect neural connectivity. We used fMRI to examine whether changes in
function brain networks are related to age related performance changes.
Preliminary results suggest that aging indeed appears to be associated with
changes in specificity of functional networks.

Talk 2:

Two hemispheres for better memory in old age: role of executive functioning.

Lucie Angel, Séverine Fay, Badiâa Bouazzaoui, Michel Isingrini
University François Rabelais of Tours, France, UMR-CNRS 6234 CeRCA

A central challenge facing the cognitive neuroscience of aging is to determine
whether age-related changes in brain activity reflect processes that are beneficial,
detrimental, or inconsequential to cognitive functions. An intriguing result from
brain imaging studies of cognitive aging is evidence of reduced hemispheric
asymmetry during aging. This experiment explored the functional significance of
this age-related hemispheric asymmetry reduction associated with episodic
memory and the cognitive mechanisms that mediate this brain pattern. ERPs were
recorded while young and older adults performed a word-stem cued-recall task. We
used correlational and regression approaches to investigate directly the
relationship between episodic memory performance, executive functioning and the
lateralization of the ERP parietal old/new effect (indexed by an individual index of
lateralization), in young and older adults. Results confirmed that the parietal
old/new effect was of larger latency and reduced magnitude and less lateralized in
the older group than the young group. Analyses also indicated that the degree of
laterality of brain activity determines the accuracy of memory performance and
mediates age-related differences in memory performance among older
participants. In addition, they confirmed a cascade model in which the individual
level of executive functioning of older adults mediates age-related differences in
the degree of lateralization of brain activity, which in turn mediates age-related
differences in memory performance.

Talk 3:

The brighter side of brain aging: about the relationship between cognitive decline, emotional reactivity, and physical fitness.

Benjamin Godde
Jacobs Center on Lifelong Learning and Institutional Development. Research group “Neuroscience and Human Performance”, Jacobs University, Bremen, Germany

Several studies have demonstrated differences between older and younger adults
in processing negative emotional information. For example, older participants
recall and/or recognize fewer negative pictures than young adults, even when age-
related differences in memory performance are controlled. Moreover, older adults
report less negative affect in everyday life than younger adults do. Age-related
differences in motivation as well as cumulative experiences and learning have
been discussed as being at the basis of this age-related difference.
We tested the hypothesis that also neural decline and thus brain aging might
account for a reduced negativity in older adults. 82 participants between 62 and 79
years of age were examined with functional MRI during performance of several
cognitive and emotional tasks. Overall, our data support the hypothesis that a
higher functional brain age is associated with reduced processing of negative
emotional stimuli in older adults.
In a next step, we performed a one-year physical intervention study with the
participants (cardiovascular walking training, 3 times a week, 1 hour each). As
expected, the intervention group, as compared to a control group, improved their
performance in the cognitive tests. In addition they revealed more youth-like
activation patterns in the brain during the cognitive tasks. What is more, increased
physical fitness and rejuvenation of brain activation patterns were related to more
negative arousal.
Overall, the data support our hypothesis that age-related changes in the frontal
cortex have not only an impact on executive functioning but also on the processing
of emotional stimuli.

Talk 4:

Vascular disease—is it a substrate for the changes with aging in thought
and affect?

J. Richard Jennings
Departments of Psychiatry and Psychology, University of Pittsburgh, USA

The physiological changes as time accumulates can be labeled aging, but we have
yet to determine whether a specific aging process occurs or whether what we call
aging is the accumulation of the chronic diseases pandemic with age—
cardiovascular disease, arthritis, and cancers. Any study of the aging of
psychological characteristics, e.g. change in affect or cognition, with a
representative sample of the elderly is in fact also a study of these chronic
diseases. An attempt to study pure aging must first be acknowledged as not
representative of the population and must second cope with the likelihood that
some disease is present but not detected despite careful screening. If an
independent process of aging does exist, it likely co-exists with chronic disease and
it may not be a single process but multiple processes with varying influences on
different psychological functions. Various proposed markers of aging will be
discussed. The issue will be illustrated (but hardly solved) by illustrating aging and
disease effects in aging samples that have blood pressure assessed. Blood
pressure is of particular interest as some researchers have characterized the
psychological effects associated with hypertension as accelerated aging. Affective
and cognitive correlates of blood pressure/aging(?) as well as their functional brain
representations will be discussed.

Talk 5:

To buy, or not buy: Aging and understanding of spoken language in a naturalistic ‘stock price monitoring’ task

Stephan Getzmann & Michael Falkenstein
Leibniz Research Centre for Working Environment and Human Factors( IfADo), Dortmund, Germany

Numerous studies suggested an age-related decline in speech perception under
difficult listening conditions. Here, spoken language understanding of two age
groups of listeners was investigated in a naturalistic “stock price monitoring” task.
Stock prices of listed companies were simultaneously recited by three speakers at
different positions in space and presented via headphones to 14 younger and 14
older listeners (age ranges 19-25 and 54-64 years, respectively). The listeners had
to respond when prices of target companies exceeded a specific value, but to
ignore all other prices as well as beep sounds randomly interspersed within the
stock prices. Older listeners did not produce more missing responses, or longer
response times than younger listeners. However, differences in event-related
potentials indicated a reduced parietal P3b of older, relative to younger, listeners.
Separate analyses for those listeners who performed relatively high or low in the
behavioural task revealed a right-frontal P3a that was pronounced especially in the
group of high-performing older listeners. Correlational analyses indicated a direct
relationship between P3a amplitude and spoken language comprehension in older,
but not younger, listeners. Furthermore, younger (especially, low-performing)
listeners showed a more pronounced P2 on irrelevant beep sounds than older
listeners. These subtle differences in cortical processing between age groups
suggest that high performance of older middle-aged listeners in demanding
listening situations is associated with increased engagement of frontal brain areas,
and thus the allocation of mental resources for compensation of potential declines
in spoken language understanding.