| By: |
Liam Delaney (Geary Institute, University College Dublin);
Caroline Rawdon (Geary Institute, University College Dublin + Department of Psychology, National University of Ireland, Maynooth, Co. Kildare);
Kevin Denny (Geary Institute, University College Dublin);
Wen Zhang (Geary Institute, University College Dublin);
Richard A.P. Roche (Geary Institute, University College Dublin + Department of Psychology, National University of Ireland, Maynooth, Co. Kildare) |
| Abstract: |
The way people make decisions about future benefits termed discounting - has
important implications for both financial planning and health behaviour.
Several theories assume that, when delaying gratification, the lower weight
given to future benefits (the discount rate) declines exponentially. However
there is considerable evidence that it declines hyperbolically with the rate
of discount being proportionate to the delay distance. There is relatively
little evidence as to whether neural areas mediating timedependent discounting
processes differ according to the nature of the task. The present study
investigates the potential neurological mechanisms underpinning
domain-specific discounting processes. We present high-density event-related
potentials (ERPs) data from a task in which participants were asked to make
decisions about financial rewards or their health over short and long
time-horizons. Participants (n=17) made a button-press response to their
preference for an immediate or delayed gain (in the case of finance) or loss
(in the case of health), with the discrepancy in the size of benefits/losses
varying between alternatives. Waveform components elicited during the task
were similar for both domains and included posterior N1, frontal P2 and
posterior P3 components. We provide source dipole evidence that differential
brain activation does occur across domains with results suggesting the
possible involvement of the right cingulate gyrus and left claustrum for the
health domain and the left medial and right superior frontal gyri for the
finance domain. However, little evidence for differential activation across
time horizons is found. |