Canadians, like other people living at higher latitudes, often experience seasonal changes in sleeping patterns, appetite, mood, and energy levels between the winter and summer seasons, but there has been little research to explain why. Fern Jaspers-Fayer is studying the impact of season on thoughts, moods and behaviour. These changes occur along a continuum from normal to abnormal, with severe winter depression, or Seasonal Affective Disorder (SAD), at one extreme. Fern is identifying the changes in electrical brain activity associated with SAD, and will determine whether these changes disappear in the summer. The results should help explain the brain mechanisms involved in SAD, leading to better therapies for the condition and better ways for everyone to chase away the winter blues.