MRC PhD students

Psychobiological correlates of emotion during pregnancy

Background
This study focuses on the construct of ‘emotional memory’ particularly the perception of, and selective attention to emotional stimuli in the environment. During pregnancy, changes occur in cognitive-affective processes, and this is presumably mediated by changes in neurocircuitry and its underlying molecular biology. Pregnant women demonstrate impaired attention, concentration and memory. It is hypothesized that changes in emotional processing also occur during pregnancy, which are mediated in part by changes in prefrontal cortex and changes in sex hormones and cortisol.

Aims

• To determine the relation between selective attention to negative stimuli in pregnant women; and anxiety traits and exposure to stressful life events. 
• To obtain near-infrared spectroscopy (NIRS) images of prefrontal brain activity in anxious and stressed pregnant women in comparison with non-anxious and unstressed pregnant controls, when exposed to emotional facial stimuli of anxiety and fear, and examine possible differences in activation. 
• To determine the relation of possibly confounding factors including nutritional factors, sleep

Participants
Healthy pregnant women (n=50), aged 18 years and older are currently recruited from the Bishop Lavis obstetrics unit. A longitudinal research design is followed with evaluations taking place on four occasions: 13-14 weeks, 22-23 weeks and 32-33 weeks of gestation, and six weeks after pregnancy.

Psychometric assessments
Mothers are screened for general distress, trait and state anxiety, temperament and character, and mental status. Alcohol consumption and smoking dependence are also assessed. Assessments of selective attention are then performed, with a special emotional Stroop task. A distinction is being made between mothers with high levels of stress or anxiety with the K10, and those with normal levels. The latter group will serve as controls. The K10 is a measure of general distress. Women scoring above 20 on the K10 will be screened by a psychologist using the Structural Clinical Interview (SCID) for psychiatric disorders. 

Endocrinology
Blood samples are taken for the assessment of the steroidal hormones estrogen and progesterone, folate and vitamin B12. Saliva samples are also taken for cortisol measurement.

Brain imaging
Brain activity in the mother is measured by near infrared spectroscopy (NIRS) while performing the conventional Word Stroop task and viewing faces with different emotional expressions. NIRS detects oxygenated versus de-oxygenated blood flow patterns with light transmitted through electrodes placed on the scalp. 

This study is supervised by Prof Dan J. Stein, Director: MRC Research Unit on Anxiety and Stress Disorders / Head: Dept Psychiatry, UCT; Dr Bavi Vythilingum, Consultant: Dept Psychiatry, UCT; and Dr Christine Lochner, Clinical Psychologist, Dept Psychiatry, US.