Decision making mechanisms in the human brain

Green, N. (2012). Decision making mechanisms in the human brain. Freie Universitaet Berlin.

The neural basis of the decision threshold is investigated and the goal of the research is to provide a complete account of the neural correlates when making choices.

The research evolved using a number of projects. In the first project, an fMRI study was undertaken  to determine reward maximization in a perceptual decision making task within the framework of the Drift Diffusion Model. It was found that decision threshold influences performance where a lower threshold leads to faster but less accurate decision.

In the second project, the researcher investigated neurocomputational models of optimal decision making using subjects suffering from Parkinson’s Disease using a perceptual decision-making paradigm. Deep brain stimulation of the subthalamic nucleus and changing of instructions were introduced. It was found that the subthalamic nucleus is important for dealing with decision conflict in perceptual decisions.

In summary, the decision threshold was found to be important for decision making.

MY NOTES

See page 33 for suggestions for future research “Open questions that I consider valuable in order to arrive at a complete account of the decision threshold are first the question on the invariance of decision threshold mechanisms across different modalities and tasks. In this context we have to consider known effects of slight changes, i.e. stimulus duration (Rüter et al., 2012), or model parameterization (Forstman et al., 2010; van Ravenzwaaij et al., 2012;) may all have severe effects on the observed results and their conclusions. Secondly, the temporal profile for the adjustable decision threshold has been only theoretically investigated (Simen et al., 2009). This aspect is potentially very important, in learning or temporal processing for instance (cf. Simen et al., 2011). Thirdly, one might ask under which naturalistic conditions are optimal strategies achievable (cf. Kacelnik et al., 2011). We know that human and animal choices tend to be suboptimal in complex naturalistic environments. How does this fit with current computational models (cf. Bogacz et al., 2010a; Newell and Lee, 2010)? A first step in addressing this question would be to see how current models could explain and predict more complex decision situations. An example for that would be the investigation of the decision threshold mechanism in approach-avoidance situations, in which both cognitive as well as emotional attributes influence decision making (cf. Busemeyer et al., 2002).”

REFERENCE

Green, N. (2012). Decision making mechanisms in the human brain. Freie Universitaet Berlin.

See Green article for other references