Where dreams are made

<body leftmargin="0" bgcolor="#000060" text="#FFFFFF" link="#FFFF00" vlink="#FF9900"> <h1 class="title"><b><font face="Arial" size="4">Where dreams are made</font></b></h1> <p class="subtitle"><font face="Arial" size="1">Posted Sept. 10, 2004<br> Courtesy John Wiley & Sons, Inc. and<br> World Science Staff</font></p> <p><font size="2" face="Arial"><b><br> Scientists are learning new facts about dreaming, including which part of the brain produces dreams, by studying a woman who lost her ability to dream.</b></font> </p> <p><font size="2" face="Arial"><b>The 73-year-old woman had a stroke in the post cerebral artery, a blood vessel that supplies blood to the back of the brain. The stroke damaged an extensive area of brain tissue and eliminated her dreams for about a year, the scientists reported.</b></font></p> <p><b><font size="2" face="Arial">"How dreams are generated, and what purpose they might serve, are completely open questions," said Claudio L. Bassetti of the University Hospital of Zurich in Switzerland. The findings with the patient show for the first time which specific brain areas need to be damaged to wipe out dreams, they said. </font></b></p> <p><b><font size="2" face="Arial">When the stroke cut off blood flow to a small area deep in the back of the woman's brain, she lost several brain functions, mostly vision-related. Fortunately, the visual problems went away within a few days of the stroke. But a new symptom emerged: her dreams stopped. <br> <br> Such loss of dreaming, along with visual disturbances, following brain damage is called Charcot-Wilbrand syndrome, named for the neurologists  who first described it in the 1880s. The syndrome is quite rare, especially cases that lack symptoms other than dream loss. </font></b></p> <p><b><font size="2" face="Arial">Bassetti and colleague Matthias Bischof, realized that this woman's misfortune might provide valuable answers to which brain area produces dreams.<br> <br> For six weeks following the stroke, the researchers studied her brain waves as she slept. They found her sleep cycle was normal. During a part of the sleep cycle called REM (rapid eye movement sleep) -- during which dreams normally occur -- there were no abnormal brain wave patterns, the researchers said. This seems to confirm that different brain systems drive dreaming and REM sleep, they added.<br> <br> Before the stroke, the patient recalled, she had dreamt three to four times a week. She now reported no dreams, even when awakened during REM sleep. <br> <br> With time, some dreaming did return. A year after the stroke, she had occasional dreams, but no more than one per week, and the dreams were less vivid and intense than before the stroke. <br> <br> Using brain scans, Bischof and Bassetti determined that the stroke had damaged areas located deep in the back half of the brain. Recent research has shown that some of this region is involved in the visual processing of faces and landmarks, as well as the processing of emotions and visual memories, a logical set of functions for a brain area that would generate or control dreams. <br> <br> "Further conclusions about this brain area and its role in dreams will require more studies analyzing dream changes in patients with brain damage," said Bassetti. The researchers published a study on the findings in September 10 online issue of the research journal Annals of Neurology.  </font></b></p> <p class="MsoNormal"> <font size="2" face="Arial"><b>* * * * *</b></font> </p> <p class="MsoNormal"> <font size="2" face="Arial"><b>Send us a <a href="mailto:editor@world-science.net">comment</a> about this story</b></font> </p> </body>