Accordingly, Westerners are more likely to focus on some salient ob jects or con-
tents (”analytic” attention), whereas East Asians are more likely to attend to
the global context (”holistic” attention) of an object, and its broad spectrum of
perceptual and conceptual fields, in addition to its local characteristics (see e.g.
Masuda & Nisbett, 2001; Kitayama, Duffy, Kawamura, & Larsen, 2003; Chua,
Boland, & Nisbett, 2005).
Chiao & Ambady (2007) have recently proposed a ”cultural neuroscience”
approach in order to integrate biological perspectives into endeavors of cultural
psychology. This approach employs both biological (e.g., neurophysiological,
neurogenetic, and neuroendocrinological methods) and cultural psychological
experiments, in a manner similar to neuroeconomics unifying biopsychology and
economics (Glimcher & Rustichini, 2004; Lee, 2005; Loewenstein et al., 2008;
Sanfey et al., 2006; Zak, 2004). Furthermore, a recent neuroimaging study (Hed-
den et al., 2008) identified neural correlates of cultural differences in attention
control in simple visual attention tasks. Therefore, it is highly important for fur-
ther neuroeconomic investigations to incorporate neurocomputational processes
mediating attention in order to establish neuroeconomically plausible models of
decision-making.
4 Attention and perception in neural valuation
of delayed rewards
In neuroeconomic studies of the valuation of delayed rewards, it has been re-
ported that (i) immediate rewards activate midbrain regions (McClure et al.,
2004, 2007), and (ii) subjective value of the delayed reward is encoded as the
midbrain dopaminergic activities (Kable & Glimcher, 2007). Regarding the
role of temporal cognition in intertemporal choice, Wittmann and colleagues re-
ported that the psychological time is represented in the striatum (Wittmann et
al., 2007); while no neuroimaging study to date examined the neural correlates
of attention allocation during intertemporal choice.
Recent behavioral economics studies (Ebert & Prelec, 2007; Zauberman et
al., 2008) have demonstrated that modulation of attention to time perspectives
(time-sensitivity) changes the human intertemporal choice behavior by shifting
the functional form of the psychophysical time-perception from a logarithmic to
a linear function. This is consistent with the psychophysical account of hyper-
bolic discounting (Takahashi, 2005, 2006). Together, these studies suggest that
control of attention allocation to time explains both hyperbolic and subadditive
discounting.
Specifically, (i) if a subject pays more attention to the delayed reward but less
attention to the time-length of delay (”time-insensitivity”), her/his temporal
discounting may be inconsistent due to non-linearly distorted time-perception
(i.e., hyperbolic discounting), and (ii) if a subject focuses her/his attention
on each temporal ”segment” along the future time (i.e., ”analytic” temporal
cognition) rather than overviews the future time perspective as a whole (i.e.,
”holistic” temporal cognition), her/his temporal discounting may be exagger-
ated (i.e., subadditive discounting). In both cases, it can be predicted that
narrower allocation of attention should be associated with more impulsive and
inconsistent temporal discounting behavior.