Study of Brain Function During Cognitive Tasks

Objective. The purpose of the protocol is to extend the structured event complex (SEC) model
developed by the principal investigator. Grafman (Grafman, 1995) proposed that action
sequences are represented in form of SECs in the human prefrontal cortex (PFC). An SEC is a
goal-oriented set of events that is sequentially structured and represents thematic
knowledge, morals, abstractions, concepts, social rules, event features, event boundaries,
and grammars. There are both temporal and semantic associative relations between
subcomponents of SEC knowledge. We will investigate hypotheses regarding the role of
different regions within the PFC in processing associative relations. We will also
investigate how SECs differing in psychological dimensions such as temporal duration,
complexity, and familiarity are represented and activated in the PFC. We will further
examine the temporal and semantic organization of SEC subcomponents by investigating how the
goal and outcome structure of event knowledge is represented and activated in the PFC.
Further, we will investigate how the temporal location of events within SECs are represented
and activated in the PFC. We will also investigate how goals and outcomes specifying the
temporal order and duration of SEC subcomponents are processed within the PFC. Additional
objectives are to (1) investigate the neural representation of human emotions and
decision-making based on utility estimation; (2) investigate the relationships between
cognitive and neural substrates of moral emotions and judgment (Moll et al., 2002a; Moll et
al., 2002b) with those of the SEC model developed by the principal investigator (Grafman,
1995); and (3) probe a new construct of cognitive dimensions incorporating critical
explanatory variables in social cognition such as moral emotions and social event knowledge.

Study Population. In nineteen separate studies, healthy, normal adult volunteers will
participate in experiments dealing with different kinds of associative relations in SECs
using functional magnetic resonance imaging (fMRI).

Design. The experiments we are conducting will employ within-subject, rapid event-related
fMRI designs to determine whether different types of SEC associative and other types of
relations are stored in dissociable networks in the PFC. In nineteen experiments; we hope to
automatically activate lexical, event-based and temporally-based associative and other types
of relations in SECs.

Outcome Measures. The data collected will consist of accuracy and response time measures of
cognitive performance reflecting automatic priming of associative relations and fMRI
activation images corresponding to each kind of associative relation, and accuracy and
response time measures of cognitive performance reflecting how temporal duration,
complexity, and familiarity are represented and activated. Experiments 10 and 11 will also
record donation choices made by the subjects. The results gained from this protocol will
provide further evidence for modifying, supporting, or rejecting aspects of the SEC model,
and will provide further evidence for modifying, supporting, or rejecting aspects of a
framework of social cognition such as moral behavior and social event knowledge.