The Effect of Aging on Value Based Decision-making

The attribution of value to prospects is a fundamental element of decision-making, as most
day-to-day decisions involve comparing items. Studies on aging document behaviors reflecting
difficulties in making comparisons between options, in particular when those options are
complex. Given the growing complexity of economic products (insurance, savings, mortgages or
even telephone plans), older adults may have difficulty making decisions that accurately
reflect their underlying preferences. It is plausible that this difficulty is linked to
age-related brain function decline within sectors of the lateral prefrontal cortex implicated
in working memory and cognitive control. This study assesses age-related changes in how the
brain computes value and makes value comparisons using a well-established economic paradigm,
the "generalized axiom of revealed preference" (GARP) Task, that tests the internal
consistency of a subject's preferences by offering repeated choices between bundles of goods.
A preliminary study suggests that aging is associated with greater GARP-Task inconsistency.
Although the neural correlates of GARP inconsistency have not been directly established,
indirect evidence suggests that the medial orbitofrontal cortex is important in all
value-based decision-making, and that areas in the lateral prefrontal and parietal cortices
(fronto-parietal network) are important for maintaining consistency in complex decisions
(e.g., multi-attribute decisions). Aging is associated with structural and functional
deficits within the fronto-parietal network. Therefore, the investigators believe that
studying the neural correlates of the GARP-Task is a promising approach to investigate
decision-making deficits in aging. The investigators will recruit 45 young adults, and 45 old
adults. Participants will complete the GARP-Task and an functional Magnetic resonance imaging
(fMRI) variant designed to isolate neural correlates of valuation of single items, of
multiple instances of the same item ("scaling") and of sets of distinct items ("bundles").
Brain activity will be related to diagnosis and to variance in GARP-Task inconsistency. Given
the prominence of age-related decline in working memory, the investigators hypothesize that
age will be associated with higher GARP-Task inconsistency and to deficits in conditions that
require manipulation of value signals (scaling and bundles). The investigators anticipate
that these deficits will be associated with low recruitment within the fronto-parietal
network and with reduced functional connectivity between this network and the medial
Orbitofrontal Cortex (OFC).

Inclusion Criteria:

- Healthy adults

Exclusion Criteria:

- 1- Subjects under 18yo . 2- Subjects with known cognitive disorders 3- Subjects with
visual or auditory deficits that would interfere with the ability to complete the
experimental tasks.

4- Subjects reporting having metal implants 5- Subjects with a history of major
anxiety disorder or other major psychiatric condition, 6- Subjects with a documented
or subjectively reported claustrophobia. 7- Subjects thinking they are or may be
pregnant. 8- Subjects with a history of head trauma that resulted in loss of
consciousness for more than 5 minutes.

9-Hx of seizures 10-Left Handed 11- On any medications affecting cognition 12- For
tasks involving foods: a) Currently on diet and or b) any known food allergies