Chapter 192 Split-Brain Case: Half of the Brain Was Stolen
The short body of the deceased was laid flat on the cold dissection table.
Mu Mian felt heavier than usual because this was the youngest human corpse she had ever dissected, and it was a child with Down syndrome.
Mu Mian did not dissect the head of the deceased first, but first cut open the chest and abdomen of the deceased and took out the internal organs. She first cut open the heart of the deceased and observed it carefully.
Chen Xue asked curiously: "Mian Mian, why didn't you dissect the head of the deceased first?"
"Because I want to determine the cause of death first."
"The deceased's skull was cut open, so shouldn't we first determine whether the cause of death was mechanical injury? The deceased most likely died of massive blood loss or brain tissue damage."
Mu Mian emphasized again: "The wound on the deceased's scalp showed no signs of life. This shows that his scalp was cut open after his death, and the body spots on the deceased's body are very obvious. If the cause of death was massive blood loss, his body spots would be lighter. The deceased was a child with Down syndrome, which is usually accompanied by various congenital diseases, the most common of which is congenital heart disease."
Body spots are formed by the deposition of dead red blood cells. If the deceased lost too much blood and lost a large amount of red blood cells, the body spots would be lighter.
Chen Xue said, "Do you suspect that the deceased died suddenly due to illness?"
"It's possible."
Mu Mian found that the deceased's ventricle was thicker than that of an average person, and one of the heart valves had an abnormal structure.
This requires a pathological test on the heart to further determine whether there is a problem with the deceased's heart. Mu Mian sent the deceased's heart to a testing agency for pathological testing.
Pathological testing is very troublesome and takes a long time. This is why Mu Mian dissected the deceased's internal organs first.
"Finally, we can dissect his brain." Mu Mian said excitedly.
Mu Mian cut the sutures on his head. They were ordinary black threads, not for medical use, but judging from the way the knots were tied and the suturing techniques, the person who sutured them had certain clinical experience.
After removing the stitches, Mu Mian carefully lifted the scalp, peeled off the subcutaneous tissue, and exposed the skull of the deceased.
His skull had been sawed open by an electric saw. When Mu Mian opened the skull, she found that only half of the brain tissue was left in the cranial cavity.
The murderer cut off the corpus callosum connecting the two hemispheres of the brain, divided the brain into two parts, and then took away the left half of the deceased's brain.
Chen Xue was stunned.
"The murderer actually took away the brain tissue of the deceased, and only took away the left hemisphere? Why did he take away the brain of a dead child?" Chen Xue was surprised.
Mu Mian said: "It can be used for research! Make brain slices and use them to observe pathological changes."
"Then why only steal half?"
"Maybe because the left half has research value." Mu Mian took out the remaining half of the brain tissue. She is now very interested in this half of the brain tissue.
Chen Xue looked at the brain of the deceased and said, "I suddenly remembered a famous medical experiment, the split-brain experiment. In order to treat an epileptic patient's epilepsy, Sperry cut off the patient's corpus callosum. Although the patient's epilepsy no longer occurred, this caused the patient to be unable to control his own behavior. This patient was also called a 'split-brain man'. Could the murderer be replicating this experiment?"
Sperry's split-brain experiment proved that the human brain is divided into two parts, the left brain is responsible for receiving sensory information from the right side of the human body and controlling the movements of the right side of the human body; the right brain is responsible for receiving sensory information from the left side of the human body and controlling the movements of the left side of the human body. If the connection between the two cerebral hemispheres is cut off, people will not be able to control their own behavior.
"But what's the value of replicating this experiment?" Mu Mian asked puzzledly, "The division of labor between the two hemispheres of the brain has been studied thoroughly. Moreover, the murderer cut off the left hemisphere of the deceased's brain after his death, and he couldn't observe the behavior of a dead person after the left hemisphere of the brain was removed." "
Yes, he took away a dead person's brain, and it can only be used for pathological research."
Mu Mian thought for a while and said, "There is another possibility. The murderer didn't want us to know what kind of disease had occurred in the left hemisphere of the deceased, so he stole it."
"Then why didn't he destroy the whole body? The body of the deceased is so small, he has more ways to deal with the body." Chen Xue analyzed.
Mu Mian looked at the skull of the deceased, and she couldn't figure out what the murderer wanted to do.
Mu Mian also sent the right hemisphere of the deceased's brain for pathological examination to see if his brain tissue had any pathological changes.
Case analysis meeting.
The pathological test results have not yet come out, and Mu Mian simply reported the autopsy results.
"Preliminary speculation, there are two possible causes of death: one is sudden death due to illness, the deceased may have congenital heart disease, he died suddenly of a heart attack; the other is that the deceased's brain was diseased and damaged the vital center. The pathological test report has not yet come out, and I can't determine the exact cause of death of the deceased."
Mu Mian continued: "The murderer sawed open the deceased's skull and stole the left hemisphere of the deceased's brain. Whether it is the suturing technique or the craniotomy technique, the murderer's operation is perfect. It is reasonable to speculate that the murderer should have rich clinical experience, and he may even be a brain surgeon."
Mu Mian showed a photo of the deceased's cranial cavity on the screen.
Everyone looked at the deceased's cranial cavity with only half of the brain tissue left, and they felt very incredible.
Xiao Zhang said, "Why did the murderer only take away half of the brain? Wouldn't it be more convenient to take away the whole brain?"
Mu Mian said, "I find it strange too. The murderer's behavior is very contradictory."
"Could he have mental problems?"
Lin Sen said, "If so, he is likely to commit crimes again."
Xiao Wang reported the results of the trace examination: "In that flower bed, we extracted two types of footprints. One of the footprints belonged to the sanitation worker who reported the case, and the other footprint was size 41. The brand of the shoes could not be determined from the shoe prints. Only the fingerprints of the person who reported the case were detected on the child's clothes."
Fang Rui showed the photo on the screen. On the soil layer of the flower bed, the murderer wrote the symbol "Ψ" in blood. The handwriting was very neat, and the words were slightly smaller than the thumb.
"After testing, the blood used to write this symbol was the blood of the deceased," Chen Xuehui reported.
Xiao Zhang held his mobile phone and muttered, "This letter is the ancient Greek letter Psi. It is written on the Internet that it has many meanings. In mathematics, it represents the reciprocal sum of the Fibonacci constants; in biology, it is the symbol of pseudouracil... In astronomy, it represents Neptune; it also represents Poseidon..."
Everyone was annoyed by Xiao Zhang's nagging. "Okay, we can surf the Internet by ourselves, so we don't need to read anymore. The question now is, we need to know why the murderer left this symbol."
Mu Mian said, "This symbol is also on the cover of the experimental psychology textbook. It is a symbol of psychology. In the original meaning of ancient Greek, it represents the soul."