IIRC those were scans of primate brains. A more recent and comprehensive study conducted by Dr. John H. Halpern, Director of the Laboratory for Integrative Psychiatry in the Division of Alcohol and Drug Abuse at McLean Hospital and Assistant Professor of Psychiatry at Harvard Medical School found no residual cognitive effects in humans.
"New Study Finds No Cognitive Impairment Among Ecstasy Users
[...] a team of researchers has conducted one of the largest studies ever undertaken to re-examine the cognitive effects of ecstasy, funded by a $1.8 million grant from the National Institute on Drug Abuse (NIDA) and published in the journal Addiction."
Conclusion from the actual study (journal behind paywall):
"In a study designed to minimize limitations found in many prior investigations, we failed to demonstrate marked residual cognitive effects in ecstasy users. This finding contrasts with many previous findings—including our own—and emphasizes the need for continued caution in interpreting field studies of cognitive function in illicit ecstasy users."
"New Study Finds No Cognitive Impairment Among Ecstasy Users
[...] a team of researchers has conducted one of the largest studies ever undertaken to re-examine the cognitive effects of ecstasy, funded by a $1.8 million grant from the National Institute on Drug Abuse (NIDA) and published in the journal Addiction."
http://www.sciencedaily.com/releases/2011/02/110215081736.ht...
Conclusion from the actual study (journal behind paywall):
"In a study designed to minimize limitations found in many prior investigations, we failed to demonstrate marked residual cognitive effects in ecstasy users. This finding contrasts with many previous findings—including our own—and emphasizes the need for continued caution in interpreting field studies of cognitive function in illicit ecstasy users."
http://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2010....