Positive Emotions and Preschoolers Have you experienced periods of low mood, sadness, and depression in your past? Are you the birth mother of a 3 to 5 year old child? You and your preschooler may be eligible to participate in a research study with the University of Pittsburgh, Medical Center on how preschool children experience positive emotions. Participation will include a 60 minute laboratory visit with you and your child. If you are interested in participating, call 412-624-7991 or email pittcarelab@gmail.com to set up a visit.