DISTRESS AND ATTENTIONDISTRESS AND ATTENTIONPosner and Raichle.
"How does the ability to control attention affect the life of the infant?
For this reason it becomes important to determine if we can measure attention in infants and observe its development. To explore the development of the visual orienting network over the first year of life, we use tasks in which the subject's attention is first drawn by a cue and then by a target. Infant's eyes are fixed on a central screen at the start of each trial, and two peripheral screens are used to attract their eyes. We record the eye movements on TV tape so that they can be analyzed frame by frame. We use these eye movements as the behavior to be measured, just as in adults the key press serves as an overt measure from which we infer covert shifts of attention.
How does the ability to control attention affect the life of the infant? A major problem of infancy is the control of distress. Caregivers provide a hint of how attention is used to regulate the emotional state off the infant. Earlier than 3 months after birth, caregivers report themselves as using mainly holding and rocking to quite their infants. However, at about 3 months many caregivers, particularly in Western cultures, attempt to distract their infants by bringing their attention to other stimuli. As infants attend they are often quieted and their distress appears to diminish.
However, a systematic study conducted at the University of Oregon by Cathy Harman suggests that the loss of overt signs of stress is not always accompanied by a genuine loss of distress. Instead, some internal system appears to maintain the initial level of distress, and the overt distress returns if the infant loses its orientation to the novel event. A possibly related phenomenon occurs in adults. Adults who report themselves as able to focus and shift attention also say they are less prone to depression and anxiety than those who report themselves as less able to control their attention. Attention may serve to control levels of distress in adults in the way somewhat similar to what is found early in infancy. Indeed, many of the ideas of modern cognitive therapy are based upon the link between attention and depression or anxiety. For example, people in therapy for depression may be trained to attend to positive life events. And directing attention away from painful stimuli has long been known to lessen the experience of pain.
The images from this study immediately revealed striking increases in blood flow in the frontal cortex, especially on the left side. Conversely, decreases in blood flow appeared in the parietal and posterior temporal lobes. The increases were found in several areas already familiar to us from our studies of the executive attention systems and language, but now these areas were, surprisingly, participants in the emotional state of depression. They included only a portion of the anterior cingulate but also the lateral surface of the frontal lobe.
The decreases in blood flow were particularly noticeable in areas associated with the attention network for orienting. Perhaps in major depression the neural systems involved in processing external information and maintaining alertness are suppressed in favor of systems involved in processing internally generated information such as thoughts and emotions.
Further study revealed additional areas whose activity distinguished normal individuals from those with depression."
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2.feb.1999
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Glosario de Carlos von der Becke.