things as brain activity, the levels of hormones and other biological molecules, and measurements of various reflexes. “I want to work back and forth between the physiological data and the starting constructs and come to things [new individual difference conceptions] that would make more sense from a neurobiological standpoint,” he said.
There are several reasons for incorporating physiology into individual differences assessments, Patrick said. First, many of the major contemporary trait-dispositional models refer to neurobiology, but the neuro-biological referents tend to be added after the fact. That is, the traits used in these models were initially developed on the basis of self-report data, and it was only afterward that researchers sought to identify their neuro-biological counterparts. By contrast, the psychoneurometric approach seeks to incorporate neurobiological indicators from the beginning so that the trait conceptions themselves are shaped by neurobiological data.
Patrick gave two other reasons for incorporating physiology into the assessment of individual differences: (1) to help address the issue of response bias (which refers to the tendency of people answering questions to be influenced by what they believe the questioner expects), and (2) to gain insight into the processes involved in how people confront and cope with a given situation. The old model of understanding behavior in a situation, the stimulus-response model, was superseded by the stimulus-organism-response model, in which processes occurring within the organism are considered crucial for understanding the connection between the stimulus and the response. Biology is an important part of understanding such relationships. Finally, Patrick noted that understanding the physiological basis of capabilities is important to the design of optimal training performance methods.
Before introducing the two main constructs that he studies, Patrick offered two key points in thinking about the psychoneurometric approach. First, neurobiological indicators of any type are complex and multi-determined. In particular, the reliable person-variance in any physiological indicator will reflect sources other than just the performance capability of interest. And second, linking the domains of physiology and adaptive performance requires a bridge of some sort. The bridging approach he employs is the use of neurobehavioral constructs, by which he means “constructs that have clear referents in both neurobiology and behavior.” Constructs of this type can serve as referents for combining physiological indicators with indicators from other domains (e.g., self-report or overt behavioral responses) to form composite measures that have meaning both psychologically and physiologically.