Attentional Phenotypes for the Analysis of Higher Mental Function

Abstract

We outline a strategy to relate normal cognitive processes to candidate genes. First, brain imaging is used to specify a cognitive process "attention" in terms of the neural networks involved. Next, evidence is presented showing that the operation of each network involves a dominant neuromodulator. Then we discuss development of a task designed to measure the efficiency of each network in normal individuals and consider evidence on the independence, reliability, and heritability of the networks. DNA from cheek swabs of subjects who performed the task are then used to examine candidate polymorphisms in genes related to the transmitters. We then examine the ability of these candidate alleles to predict the efficiency of relevant networks. This process has demonstrated that candidate genes are related to specific networks of attention to a greater degree than to overall performance as measured by reaction time and accuracy. These findings require replication and possible extension to other cognitive processes.

Human Attentional Networks: A Connectionist Model

“…This independence hypothesis has been supported by a behavioral study in which no correlation in performance was found between the three networks, measured using a behavioral testing procedure (Fan, McCandliss, Sommer, Raz, & Posner, 2002). However, in a larger study using a similar testing procedure, a significant correlation between the orienting and executive control network was found (Fossella, Posner, Fan, Swanson, & Pfaff, 2002). Interactions among other networks were also observed using a slightly modified task (Callejas, Lupianez, & Tudela, 2004).…”

Genetic relations between effortful and attentional control and symptoms of psychopathology in middle childhood

“…Moderate to high heritability affirms previous twin study results (see Introduction) and is consistent with molecular genetic studies. For example, the long repeat form of the dopamine D4 receptor gene and variants of the monoamine oxidase A gene associated with lower enzyme expression (which synthesizes dopamine) have been associated with both activation in the anterior cingulate gyrus (Fan, Fossella, Sommer, Wu & Posner, 2003) and behavioral measures of executive attention (Fossella, Posner, Fan, Swanson & Pfaff, 2002). …”

Mindfulness training modifies subsystems of attention

“…All the participants were given a variant of the ANT that was developed by Fan and colleagues and has been described in greater detail elsewhere (Fan, Fossella, Sommer, Wu, & Posner, 2003;Fan et al, 2002;Fossella, Posner, Fan, Swanson, & Pfaff, 2002). Briefly, the participants viewed a computer screen from a distance of 65 cm, and their responses were collected via two input keys on a mouse.…”