shixx279: October 2011 Archives

I was surprised by authors' idea that direct instruction is more effective and efficient than discovery learning, when I read chapter 6 in textbook. Because we always hear educational scholars advocate developing discovery learning in classes, instead of suggesting to improve direct instruction. Why do authors support opposite ideas as we heard, and what is the evidence shown?

What Is Discovery Learning and Direct Instruction?
First,we recall the conceptions of discovery learning and direct instruction. Discovery learning is a method that students find principles by themselves without teachers instructing. Direct instruction is the opposite idea, which refers to a rigorously developed, highly scripted method for teaching that is fast-paced and provides constant interaction between students and the teacher. It emphasizes the use of small-group, face-to-face instruction by teachers and aides using carefully articulated lessons in which cognitive skills are broken down into small units, sequenced deliberately, and taught explicitly.

Discovery Learning V.S Direct Instruction
It is a controversy between these two ideas. Proponents of discovery learning theory believe that discovery learning could encourages active engagement,promotes independence and most important,develops creativity and problem solving skills. However, Critics cites this method could create cognitive overload and potential misconceptions. And they suggest classical teaching method, direct instruction, is more effective and efficient than discovery learning. What does evidence show?
Studies of Learning Methods
One study is completed in the 1970s, about Project Follow Through, which was the largest educational study up to now. It examined a variety of programs and educational philosophies to learn how to improve education of disadvantaged children in grades K-3. The studies could be grounded into basic skills, cognitive skills ("higher order thinking") and self-esteem. Subjects were divided into two groups, that are receiving direct instruction and receiving discovery learning. The results showed Students receiving Direct Instruction did better than those in all other programs when tested in reading, arithmetic, spelling, and language.Also, direct instruction improved cognitive skills dramatically relative to the control groups and also showed the highest improvement in self-esteem scores compared to control groups. Therefore, direct instruction is better than discovery learning.
Yet, Another study shows direct instruction is insufficient and inappropriate in the long term by DAVID DEAN JR. and DEANNA KUHN.

In conclusion, both methods of learning have advantages. But, applying either one method alone in teaching is not a rational way. Therefore, we need consider to combine both methods during teaching.

Sleep paralysis, known as nightmare, is a kind of mystery of our daily life because most of us have to encounter it at least once in a lifetime. The statistics show that 20% to 60% of individuals reported having experienced sleep paralysis at least once in their lifetime in Canada, China, England, Japan and Nigeria.
Mystery around the world
The original definition of sleep paralysis in English is a nightmare, and is mainly considered as demons sitting on the chests of sleepers. It is similar in North American folk belief, that sleepers suffer breath difficulty after waking and are unable to move, because of perceived heavy invisible weight of demons on their chest. Also, It is considered a sign of an approaching tragedy or accident. In Mexico, it is believed that this is caused by the spirit of a dead person. Swedish people think sleep paralysis is related to a damned woman who has a super power to make nightmares when she visits villagers at night. However, Most Asian cultures consider that sleep paralysis is a ghost or dark spirit pressing on the bed.
What is sleep paralysis?
Sleep paralysis is a feeling of being conscious but unable to move or speak for a few seconds up to a few minutes. It occurs either at sleep onset, which is called hypnagogic or predormital sleep paralysis, or upon awakening that is hypnopompic or postdormital sleep paralysis. For example, one cannot move on the bed but he or she can hear or see things that do not exist. There are other symptoms like skeletal muscle paralysis and hypnagogic hallucinations or dream-like mentation during sleep.
What causes "nightmares"?
The factors that influence sleep (SP) paralysis are studied by J. A. CHEYNE at the university of Waterloo. He set two situational conditions for sleep paralysis, different body position and different timing of sleep (beginning, middle or end of sleep ) as independent variables, and the number of SP occurred during an individual's sleep as the dependent variable. In addition, the sample size was 6730 subjects. He measured REM during sleep time to examine when SP episodes occurred and compared the difference of dreams between REM and NREM, as well as the intensity of SP hallucinations.
The results showed that more subjects reported SP in the supine position, lying down on their back, than all other positions combined; SP occurred more at the middle and end of sleep than at the beginning; SP Hallucinations were found for SP timing more body position. He summarized that body position and timing of SP episodes both appeared and affected the quality of the SP experience. There is the article by J.A.CHEYNE 6726710.pdf
Do we need to worry about nightmare?
As most articles mention most of us do not need treatment for sleep paralysis. But there are some suggestions that can help us escape from nightmares. We need to improve sleep habits like getting enough sleep every night. Furthermore, we need to find doctors to treat any mental health problems and other sleep disorders that may contribute to sleep paralysis, such as narcolepsy or leg cramps.

Article links: http://www.webmd.com/sleep-disorders/guide/sleep-paralysis
http://www.stanford.edu/~dement/paralysis.html

Nerve zero is the secret cranial nerve in our brain and it is not mentioned in typical textbooks. Some anatomical evidences show the little nerve may be the hot button in our body. However its presence in human remains controversial.

Where is the mysterious nerve?
The nerve zero is in front of the olfactory nerve which was discovered by German scientist Gustav Fritsch in 1878 in the shark brain. The anatomists found it in vertebrates over the next century. That means nerve zero also in human body. Because other 12 cranial nerves have been numbered at that time, therefore, it is named nerve zero or terminal nerve.

How does it work?
One ending of nerve zero in the nose as the receptor of pheromone, another endings is located in the nasal cavity. Thus, the terminal nerve can send nerve fibers to the medical and lateral septal nuclei and preoptic areas which are sex and reproduction region that can be affected by the amygdala, hippocampus and hypothalamus, when the pheromone is received by the receptor in the nose.

Where is controversial?
There are some debates about nerve zero. Some scientists argue that nerve zero is the branch of the olfactory nerve and not a separate nerve. In other words, the sexual responses in animals body are stimulated by olfactory nerve.

What is new finding?
In 2007, Professor R. Douglas Fields suspected that nerve zero related to sex, if whales and dolphins reserved nerve zero in their brain, because they lost the sense of smell and olfactory nerve in the evolutionary exchange. He got a chance to open a pilot whale's brain and he found that a pair of nerve zero headed toward the whale's blowhole. In other words, nerve zero was a separate nerve.
More questions
However, there remains uncertain about zero nerve. We do not know the role of nerve zero in the sexual behavior in human and the dominance relationship between olfactory nerve and nerve zero is unclear.
http://mugwump.pitzer.edu/~bkeeley/pix/Portugal/Nervus_Terminalis.pdf