Underneath that iceberg there were the mechanisms of drives and motivations as well as those of reward and punishment, which are the fundamental constituents of the emotion machinery. I ventured that those were the factors most likely to play the main modifying role in the decision process, from a neural perspective, at either conscious or unconscious level. In retrospect, it is apparent that these early observations and interpretations benefited from and became part of a major revival of interest in the neuroscience of the emotions, which had been much neglected until the last decade of the twentieth century.

The new work on the emotions encompassed research in experimental animals – a prime example is Joseph Le Doux’s exploration of the fear conditioning paradigm in rodents ( Le Doux, 1996 ) – as well as the human lesion studies conducted by our group. Over a brief period of time a growing number of investigators were able to identify critical stages in the emotional process, and discover the main induction sites for emotions such as fear (the amygdaloid nuclei) and the social emotions (the ventromedial prefrontal cortices). We were also able to establish a principled distinction between emotion and feeling (see below), and to identify the insular cortex as a principal neural substrate for feelings ( Damasio, 1994 ; Damasio et al ., 2000 ). Social neuroscience and neuroeconomics were by then ready to exploit functional neuroimaging to its full advantage, a trend that has continued unabated. Adopting today’s neuroeconomics perspective, I would summarize the somatic-marker hypothesis as follows: 1. Emotion plays a role in decision making, but it should be clear that, under the term emotion I include both (a) the neural subprocesses of automated life regulation that are part and parcel of emotion action programs, namely reward and punishment processes and drives and motivations; and (b) the neural substrates of the perceptual read-outs of emotion action programs, namely emotional feelings .

2. In the original somatic-marker hypothesis outline, I suggested that the emotional influence on the decision-making process was exerted neurally, at multiple neural levels, from the high level of feelings substrates to the level of reward and punishment signaling (see Damasio, 1996 ).

Much Holding