The Amazing Brain LEVELED BOOK Y. A Reading A Z Level Y Leveled Book Word Count: 1,470.

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The Ama

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The Ama

zing

Brain

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The Amazing Brain

A Reading A–Z Level Y Leveled Book Word Count: 1,470

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The Amazing Brain Level Y Leveled Book © Learning A–Z Written by Cheryl Reifsnyder All rights reserved. www.readinga-z.com Correlation LEVEL Y T 40 40 Fountas & Pinnell Reading Recovery DRA ww w.re adi nga -z.c om

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The Amazing Brain Level Y Leveled Book © Learning A–Z Written by Cheryl Reifsnyder All rights reserved. www.readinga-z.com Correlation LEVEL Y T 40 40 Fountas & Pinnell Reading Recovery DRA 16 Glo ssa ry cer ebr um (n .) th e lar ges t par t of m any m am mal s’ bra ins; con tro ls t hin king, fee lin g, com mun ica tin g, e mot ion s, a nd s om e of t he s ens es ( p. 5 ) cor pu s the g rou p of n erv e fib ers i n the call osu m (n .) m idd le p art o f the b rai n in s om e mam mal s; c onn ect s and a llo ws com mun ica tio n bet wee n the t wo hem isp here s (p . 7 ) dec iphe r (v. ) to m ake o ut t he m ean ing o f som eth ing t hat i s dif fic ult t o und ers tand (p. 11) ele ctr ode s (n .) p oin ts t hro ugh w hic h ele ctr ici ty flo ws i nto o r out o f a dev ice , suc h as a b att ery ( p. 1 0) hem isp here s hal ves o f a sph ere o r a mos tly (n.) ro und o bje ct, s uch a s a pla net or a b rai n (p. 7 ) inte rp rets (v. ) tel ls, e xpl ain s, o r und ers tan ds t he mea nin g of s om eth ing ( p. 6 ) lob es (n.) ro und ed o r cu rve d sec tio ns o f a bod y or o rga n, s uch a s the e ar, b rai n, o r lun gs ( p. 7 ) netw ork (n .) a g rou p of t hin gs t hat a re c onn ect ed to a nd c om mun ica te w ith e ach o the r (p. 4) neuro ns (n.) ne rve c ell s th at c arr y in for mat ion wit hin t he b rai n and b etw een t he bra in a nd o the r par ts o f the b ody ( p. 4 ) 15

Protect Your Brain

Brain protection is the most important key to brain health. Shock-absorbing fluid and a hard skull guard your brain against injury. If you land on concrete, though, a fall from only two or three feet can crack your skull or bruise your brain. Swelling or bleeding inside the skull quickly cuts off the brain’s blood supply—and your brain can survive only a few minutes without oxygen. Wearing a helmet during sports provides extra protection that may save your brain—and your life.

Your brain may be the most important part of your body. Exercise, get enough sleep, and wear protective headgear to help your brain operate smoothly for years to come!

The Amazing Brain • Level Y

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The A maz ing B rai n • Lev el Y

4 The Bra in Wha t wei ghs o nly 2 per cen t of y our t ota l bod y wei ght b ut u ses mor e tha n 20 p erc ent of y ou r ene rgy ? An sw er: Y our m ost com plic ated body par t— the brai n. You r bra in n eed s ple nty o f ene rgy t o fue l abo ut 2 00 b ill ion neu ron s . T hese bra in c ells c arr y the elec tri cal sig nals nee ded f or t hou ght s, mem ori es, a nd fee lin gs. T hey ’re t he r eas on y ou c an r ide a b ike and r em em ber y our t eac her ’s n am e. Ste phe n Sm ith , a sci ent ist w ho s tu die s the bra in a t Sta nfo rd U niv ers ity M ed ica l Sch ool, s ays th at n eu ron s for m a ne tw ork with mor e th an 125 t ril lio n con nec tio ns. Y our b rai n con tai ns m ore neu ron c onn ect ion s tha n the re a re s tar s in 1 ,50 0 Mil ky W ay g ala xie s! T his c om ple x wir ing s yst em ena ble s you r bra in t o act a s the c ont rol c ent er f or you r ent ire b ody . Sig nals t rav el t hro ugh n eur ons t

o n and b rai f the b ts o nt par ere diff ody

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Table of Contents

The Brain . . . 4

Three Brains in One . . . 5

Brain Stem . . . 5

Cerebellum . . . 5

Cerebrum . . . 6

Right Brain, Left Brain . . . 7

Studying the Brain . . . 8

Brain Mapping . . . 9

“Seeing” Brain Activity . . . 10

Mind Control! . . . 11

Maintain Your Brain . . . 13

Brain Training . . . 14

Protect Your Brain . . . 15

Glossary . . . 16

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13 Mai ntai n Y our Brai n You r bra in i s an a maz ing m ach ine , and , lik e a mac hin e, i t ope rat es b est w ith p rop er c are . How do y ou k eep y our b rai n in t op c ond itio n? For s tar ter s, u se i t! E xer cis ing y our b rai n hel ps it g row i n the s am e way t hat m usc les g row w ith phy sic al e xer cis e. T ake v iol in p lay ers : The y lea rn com plic ate d fin ger m ove men ts f or t he l eft h and , and t he b rai n are a con tro lli ng t hat h and i s lar ger tha n in m ost p eop le. Diff ere nt par ts o f the b rai n act ivat e whe n doi

ng s 3D M n thi in i s bra on’ ers he p s. T tie ivi nt act ere diff RI i

s sol vin g a pro ble

m, a. e are ctiv he a n is t rai he b w in t ello he y e. T uzzl ng a p h as doi suc

The A maz ing B rai n • Lev el Y 14 Brain Training

Brain changes usually occur only in regions directly involved with your activity. However, research suggests that some “mental training” may cause broader changes. For instance, research at Harvard Medical School showed that people who practiced meditation for eight weeks had changes in brain regions used for learning, memory, and emotional control.

Physical exercise—especially exercise that raises your heart rate—also has brainwide benefits. Dr. Arthur Kramer is the director of the Beckman Institute for Advanced Science and Technology at the University of Illinois, where he studies how exercise affects the brain. “Exercising is good for your body and your brain,” Kramer says. “Research has shown that children who regularly exercise have better memories and attention and often do better on school tests.”

Sleep is another key to healthy brain function. According to Dr. Ken Paller, director of the Cognitive Neuroscience Program at Northwestern University, evidence suggests that your brain replays memories during sleep. That may help skills and information “stick” in your memory. However it works, it’s clear that getting too little sleep decreases your ability to learn and think.

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12 If t his s oun ds l ike s cie nce f ict ion , th in k aga in : Exp eri men tal m ind -co ntr olle d dev ice s alr ead y exi st! E lec tro des d ete ct t he b rai n sig nal , whi ch i s dec ode d by a c om put er. T he i nfo rm atio n can b e use d to c ont rol a m ech an ica l dev ice . Res ear che rs hop e th is t ech nol ogy c an b e use d to h elp p eop le wit h dis abi lit ies m ove a nd c om mun ica te b ett er. Th is t ech niq ue c ou ld a lso b e use d to s end bra in s ign als f rom o ne p ers on t o ano the r. I n ear ly exp eri men ts, o ne p ers on’ s “br ain s ign al” f or f ing er mov em ent t rav ele d ove r the I nte rne t to a not her roo m. T her e, a s pec ial d evi ce d eliv ere d the s ign al to a s eco nd p ers on. H is f ing er m ove d— fol low ing in str ucti ons fro m a noth er b rain . In a n exp erim ent at t he U niv ers ity o f Was hin gto n, o ne r ese arc her ( lef t) w

as ht), r (rig che ear r res the o ano net t nter he I ver t nal o n sig rai end a b e to s abl cau sin g his f ing er t o mov e on t he k eyb oar d. 5 Th ree B rai ns i n On e Neu ron s con nec t the b rai n to t he r est o f the bod y, d eliv eri ng i nst ru cti on s to m usc les a nd bri ngi ng b ack i nfo rm atio n fro m you r sen ses . The y als o con nec t the t hre e mai n par ts o f the b rai n: t he bra in s tem , cer ebel lum , a nd cer ebru m . Eac h bra in par t con tro ls s pec ifi c bod y act ivi tie s. Bra in St em The b rai n ste m is s om eti mes c alle d the liza rd bra in . Tha t’s b eca use i t doe s pre tty m uch t he s am e th ing i n liz ard s as i n you : con tro ls b ody p roc ess es th at a re e ssen tia l for s urv iva l. D ay a nd n igh t, you r bra in s tem k eep s you r bre ath ing , dig est ion , hea rtb eat , and o the r aut om atic b ody p roc ess es ru nn ing sm oot hly . Cer ebel lum Eve ry t im e you m ove y ou r bod y, y ou r cer ebe llu m is a t wor k coo rd in ati ng m usc le mov em ent s. I t add s “ta rge tin g in str uct ion s” w hen oth er p art s of y our b rai n sen d a mov em ent s ign al usi ng i nfo rm atio n suc h as y our b ody ’s c urr ent spee d a nd pos iti on. W ith the cereb ellu m’s gu ida nce , you c an t ouc h you r nos e in o ne s moo th mot ion . With out i t, t he m ove men t wou ld b e jer ky, or y ou m igh t eve n miss y our n ose c om ple tel y! The A maz ing B rai n • Lev el Y 11

Unlike electrical signals, changes in blood flow can be detected deep inside the brain.

An fMRI allows scientists to detect the precise brain regions used when you sing, laugh, or watch a scary movie—with far more detail than an EEG can provide.

Mind Control!

The ability to detect brain signals raised another question: Is it possible to decode these signals? If a computer could decipher a brain’s electrical signals, people might learn to control an artificial limb or a robot through a brain-computer interface.

Word Wise

• EEG is short for electroencephalogram (ih-LEK-troh-en-SEH-fuh-luh-gram).

• fMRI stands for functional magnetic resonance imaging.

(Left) A person reviews an MRI. (Top right) This EEG shows the brain functions of a person in a light sleep (bottom right).

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The cerebellum also stores memories of muscle movement. Muscle memories become stronger with repetition, which is why practice helps some movements—like playing guitar or skateboarding—become automatic.

Cerebrum

The cerebrum is the largest part of the brain. This is where most high-level brain activity takes place, including thought, speech, learning, and emotions. The cerebrum also interprets information from the senses. Sensory information reaches the brain as electrical signals, which the cerebrum interprets as sounds, images, and other sensations. It compares the results with your stored memories and attaches meaning. A stream of electrical impulses becomes a purple bus or a crowing rooster.

You may be surprised to learn that ignoring things is an important part of the cerebrum’s job. To understand why, take a moment to notice everything you see, hear, taste, smell, and feel. Your senses constantly flood the brain with information! By screening out some things, the cerebrum helps you focus on what remains.

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8 Stu dyi ng t he B rai n Ph in eas G age w as i nju red i n 184 8 whe n an acc ide nta l exp los ion s hot a t hre e-foo t iro n rod str aig ht t hro ugh his h ead . Am azi ngl y, G age sur viv ed. T he h ole i n his h ead d idn ’t a ffe ct h is mem ory o r his a bili ty t o th in k, b ut i t cha nge d his per son alit y. G age b eca me r ude , tho ugh tle ss, a nd as s tu bbo rn a s a tw o-y ear -ol d, s o dif fer ent f rom his o ld s elf t hat h is f rie nds s aid h e was “ no l ong er Gage .” Gag e had l ost a p ort ion o f his f ron tal l obe , a par t of t he c ere bru m th at g ove rn s em oti on s and att ent ion . His i nju ry g ave s cie nti sts o ne o f the f irs t clu es t hat s pec ifi c bra in r egi ons c ont rol s pec ifi c bra in fu ncti ons . Phi neas G age h old s the i ron r od t

hat ront nd f ye a eft e is l ugh h hro went t

al e. lob

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Right Brain, Left Brain

If you could look inside your head, you’d see that the cerebrum is divided into two halves, called hemispheres. A bundle of nerves called the

corpus callosum connects the hemispheres and

carries messages between them. The hemispheres control opposite sides of the body. Your left hemisphere sends the signal to raise your right hand; your right brain is in control when you shake your left foot. Although some tasks can be done by either hemisphere, the two are not identical. The right brain usually controls creativity, artistic skills, and interpreting what you see. The left brain generally controls speech, writing, and math skills.

Each brain hemisphere has four sections, or

lobes, and each lobe has specific jobs. However,

scientists didn’t realize this until the 1800s, when a doctor recorded the strange story of Phineas Gage.

Left Hemisphere Cerebrum Corpus Callosum Cerebellum Brain Stem Right Hemisphere

Parts of the Brain

9 Bra in M app ing Doc tor s stu die d Gag e’s c ase f or m any y ear s. The n, i n 191 4, W orl d War I b ega n. L arg e num ber s of s old ier s suf fer ed b rai n inj uri es, a nd t he i nju rie s to c ert ain b rai n reg ion s con sis ten tly c aus ed t he sam e sym pto ms. W ith t his i nfo rm atio n, d oct ors wer e abl e to b egi n cre ati ng m aps o f bra in r egi ons and t hei r fu nct ion s. T ryi ng t o lea rn a bou t the bra in b y stu dyi ng b rai n inj uri es w as m uch l ike try ing t o lea rn a bou t car s by s tud yin g bro ken eng ine s: S cie nti sts c oul d ide nti fy e ssen tia l bra in reg ion s, b ut t hat w as a bou t it. Functions of Different Br ain Lobes Fron tal Lobe • P robl em- ving sol

• Att ent ion • Spe akin g • E mot iona l l tro con Parie tal Lob e • Mov ement • R eco gni tio n a nd n atio riz ego cat

of o bje cts Occ ipit al L obe • Visi on • S hape reco gnit ion Tem por al L obe • Hea ring • Memor y • U nder sta nding ech spe

The A maz ing B rai n • Lev el Y 10

“Seeing” Brain Activity

For a clearer understanding of brain function, they needed a way to study healthy brains. A German scientist created a machine that could measure the electrical activity in the brain. This machine, called an EEG, provided a partial solution.

Everything you do—running, singing, thinking, and more—begins with tiny electrical signals in your brain. An EEG measures these signals through electrodes placed on the head’s surface. Researchers can “see” brain activity when you walk, talk, read, and more.

Unless electrodes are surgically implanted inside a person’s skull, though, an EEG can only detect signals near the brain’s surface. Observing activity deeper in the brain was difficult and potentially dangerous until a test called an fMRI became available.

Unlike an EEG, which measures electrical activity, an fMRI identifies active brain regions by measuring blood flow. This gives an indirect measurement of brain activity because electrically active neurons require more oxygen. Since blood is your body’s oxygen delivery system, brain areas with more blood flow generally have more electrically active neurons.