Browsing by Subject "Salience"

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Open Access
Neurophysiology and Neuropharmacology of Decisions
(2009) Long, Arwen
Negotiating the complex decisions that we encounter daily requires coordinated neu-
ronal activity. The enormous variety of decisions we make, the intrinsic complexity
of the situations we encounter, and the extraordinary flexibility of our behaviors
suggest the existence of intricate neural mechanisms for negotiating contexts and
making choices. Further evidence for this prediction comes from the behavioral al-
terations observed in illness and after injury. Both clinical and scientific evidence
suggest that decision signals are carried by electrical neuronal activity and influenced
by neuromodulatory chemicals. This dissertation addresses the function of two puta-
tive contributors to decision-making: neuronal activity in posterior cingulate cortex
and modulatory effects of serotonin. I found that posterior cingulate neurons respond
phasically to salient events (informative cues; intentional saccades; and reward deliv-
ery) across multiple contexts. In addition, these neurons signal heuristically guided
choices across contexts in a gambling task. These observations suggest that posterior
cingulate neurons contribute to the detection and integration of salient information
necessary to transform event detection to expressed decisions. I also found that
lowering levels of the neuromodulator serotonin increased the probability of making
risky decisions in both monkeys and mice, suggesting that this neurotransmitter con-
tributes to preference formation across species. These results suggest that posterior
cingulate cortex and serotonin each contribute to decision formation. In addition, the
unique serotonergic pro jections to posterior cingulate cortex, as well as the frequent
implication of altered serotonergic and posterior cingulate function in psychiatric dis-
orders, suggest that the confluence of cingulate and serotonergic activity may offer
key insights into normal and pathological mechanisms of decision making.
Open Access
The Electoral Politics of Vulnerability and the Incentives to Cast an Economic Vote
(2007-10-16) Singer, Matthew McMinn
The relationship between economic performance and support for the incumbent government varies across voters and electoral contexts. While some of this variation can be explained by factors that make it easier or harder to hold politicians accountable, an additional explanation is that the electoral importance of economic issues varies systematically across groups and contexts. Because issues that are personally important tend to be more easily accessible when voting, we prose that exposure to economic shocks generates higher incentives to place more weight on economic conditions when voting. We test this hypothesis using archived and original survey data from Argentina, Mexico, and Peru. The analysis demonstrates that economic vulnerability enhances the economy's salience. Specifically, poverty generates incentives to cast an egotropic vote while wealth, insecure employment, informal employment, and exclusion from governments welfare programs enhances sociotropic voting because these groups have greater stakes in the national economy. By implication, elections in developing countries with large numbers of vulnerable voters should be more strongly contested over economics despite the weak institutional environment that potentially undermines the ability of voters to hold politicians accountable. Aggregate elections returns and the CSES survey support this proposition and demonstrate that economic voting is substantially more common in Latin American than in Western Europe or North America. Thus variations in economic voting provide opportunities to not only learn about the conditions under which elections can serve as mechanisms of accountability but also a laboratory to model the process of preference formation and the demands voters place on their representatives.