Decision Making – Neural Correlates

Decision Making – Neural Correlates

The Neuronal Substrates of Decision Making Processes

Anyone who ever had at least one eye exam, knows that making decisions, even trivial simple decisions can be quite hard. For those lucky enough to have perfect vision, there comes a time during an exam at the ophthalmologist when the doctor asks you to chose between options one and two. The two options appear very similar and it can be quite hard to differentiate which of the two allows for clearer vision. Also, some people are just better than others at making decisions. But I digress, as the purpose of the present essay is to discuss the neural correlates of the process of making decisions. In other words, to examine which parts of the brain are most active during the activity.

Neuroscience is an amazing field and relies mainly on neuroimaging data.

Philiastides and colleagues (2011) used rTMS* to study how the brain processes perceptual decision making. Thus, according to their report, the left DLPFC accumulates evidence up to a certain point when a choice is made.

Haegens et al. (2011) recorded LFPs (allow to target neuronal populations, while spikes isolate single neurons) across the monkey brain, while the animal was completing a vibrotactile discrimination task.The neural correlates of somatosensory decision making in monkeys turned out to be S1, S2, DPC, MPC, and M1, where oscillations in beta band reflect the dynamics of the event. Of course, in such experiments, cortical activity is recorded contralaterally.

Furthermore, apparently the brain would act on economic utility theory, by assigning value to alternatives, computing and comparing before making a decision. Hence, Jenison and coauthors (2011) were interested in the organizational and mechanical aspects of this computation. They suggest that amygdala neurons contained in the basolateral nucleus react to preferential worth assignment to comestible items.Likewise, the BLA subnucleus would participate intensely in the calculations. Alternatively, the OFC, which interconnects heavily with the amygdala, has been consistently cited as the one active during “the encoding of stimulus value at the time of choice” (Ibid, 331).Moreover, the authors draw impressively on Pavlovian and classical conditioning in explaining the importance thatbasolateral amygdala represents for this function.

Is the picture above an animation? Regardless of the answer given, the fact of answering would involve decision making. Image: Copyright © Elena

Rilling & Sanfey (2011) further confirm the PFC’s role in decision making, particularly in stable environments. As previously mentioned, neuroscientific experiments can incorporate elements from economics. For example, game theory and bidding behavior act as stimuli chosen for studying social decision making in the laboratory. Finally, the work underscores that different regions of the PFC are involved in dissimilar types of moral, ethical and interpersonal decisions. Inter alia, the anterior insula, as well as serotonin (neurotransmitter), testosterone (hormone) and oxytocin (neuropeptide) also mediate decisions.