1. The Nervous System

2. Quick! Say aloud what color you see in every word, NOT the word you read. Go from left to right, from top to bottom.

3. Not easy, right? This task is called the Stroop Test, and is used in neuropsychological evaluations to measure mental vitality and flexibility, since performing well requires strong attention, inhibition and self-regulation capability (also called executive functions).

4. –>You will watch a brief video clip, and your challenge is to count how many times that the players wearing white pass the basketball. 

5. In the text there are actually 10 F’s
In the text there are actually 10 F’s! Generally all people under count number of F’s because they fail to notice the letter ‘f’ in the word ‘of’. The words like ‘of’ are unconsciously processed by our brain because they aren’t considered important.

6. Are the squares inside the blue and yellow squares all the same color?

7. The smaller squares inside the blue and yellow squares are all the same color. They seem different (magenta and orange) because a color is perceived differently depending on its relation to adjacent colors (here blue or yellow depending on the outer square).

8. Are the horizontal lines straight or crooked?

9. The horizontal lines are straight, even though they do not seem straight.  In this illusion, the vertical zigzag patterns disrupt our horizontal perception.

10. How many legs does this elephant have?

11. Tricky, isn’t it?! This picture is an impossible picture that also contains some subjective contours, such as the Kanizsa Triangle below: A white triangle (pointing down) can be seen in this figure even though no triangle is actually drawn. This effect is known as a subjective or illusory contour. The contour of the triangle is created by the shapes around it.

12. Can you put the fish in the fishbowl?
Stare at the yellow stripe in the middle of the fish in the picture below for about sec. Then move your gaze to the fish bowl.

13. Did you see a fish of a different color in the bowl
Did you see a fish of a different color in the bowl? You have just experienced an afterimage. In the retina of your eyes, there are three types of color receptors (cones) that are most sensitive to either red, blue or green. When you stare at a particular color for too long, these receptors get “fatigued.” When you then look at a different background, the receptors that are tired do not work as well. Therefore, the information from all of the different color receptors is not in balance. This will create the color “afterimages.”

14. Are the two horizontal lines of the same length?

15. The two horizontal lines are of the same length, even though the one at the bottom seems longer. As you know, the visual angle gets smaller with distance, so the brain automatically perceives objects at farther distances to be bigger.
In general, lines that have inward flaps, such as corner of a building, are relatively the nearest points of the overall object. Similarly, lines with outward flaps are found at the longer distance, as the farthest corner of a room. So in the Mueller-Lyer illusion, the brain perceives the line with outward flaps to be at a farther point as compared to the line with inward flaps. Consequently, the brain perceives the line with outward flaps to be longer.

16. Do you see gray dots at the intersections of the white lines?

17. There are not gray dots in this grid
There are not gray dots in this grid. However “ghostlike” gray blobs are perceived at the intersections of the white lines. The gray dots disappear when looking directly at an intersection. This illusion can be explained by a neural process happening in the visual system called lateral inhibition (the capacity of an active neuron to reduce the activity of its neighbors).

18. Are the two orange circles of the same size?

19. The two orange circles are exactly the same size,even though the one on the left seems smaller. This size distortion may be caused by the size of the surrounding circles or by their distance to the center circle.

20. Does Lincoln’s face look normal?

21. It seems normal but now, look at it upright: Lincoln’s eyes do not look quite right!
Some neurons in the brain seem specialized in processing faces. Faces are usually seen upright. When presented upside down, the brain no longer recognizes a picture of a face as a face but rather as an object. Neurons processing objects are different from those processing faces and not as specialized. As a consequence these neurons do not respond to face distortions as well. This explains why we miss the weird eyes when the face is inverted.

22. Can you see a baby?

23. Another great example of an illusory contour
Another great example of an illusory contour! The baby’s head is on the left, the baby’s feet are against the trunk of the tree on the right.

24. Slowly move your right foot in a clockwise circle
Slowly move your right foot in a clockwise circle. Then write a number 6 with the same hand on your desk with your pointer finger. What happens?

25. Answer
You can do this with practice, but it is incredibly hard to do. If you try and do that number 6, you'll find that number 6 flips around, and you start drawing it backwards.
The reason for this has to do with the way your brain codes for movement. You can easily do this if you use the opposite sides of the body. If you've got a hand which you do a clockwise circle with and your right hand and then you use your left leg, you'll easily do a circle in the anticlockwise direction because you're using two different sides of your brain.
If you're trying to use the same side of your body, the part of the brain which codes for movements tells a muscle what to do. You have a cluster of nerve cells which send a signal when you want to move a part of the body in a certain direction. Those nerve cells don't just switch on muscles that move say, just the arm. They switch on muscles which would move your leg in the same direction too, but they turn them on a bit less than the motor neurons that control the arm. So basically, you're making it easier for your leg to move in the same direction as your arm. But it takes a little bit more switch on to make the leg move as well. Therefore, if you try then to make a movement in the opposite direction with the leg, you're basically making another group of nerve cells move in the opposite direction. So the two things are trying to fight it out and whichever one wins actually ends up going in that direction.

26. Ready. Set. Go! (and please don’t rotate your device, or your head…)
Visuospatial skills are used everyday in many ways, ranging from going from one room to another in your house to navigating in a new city.
Here is a brain teaser to stimulate your mental rotation cognitive skills.
For each number in the matrix below, decide whether it is a normal or reversed number, as in this example:
Ready. Set. Go! (and please don’t rotate your device, or your head…)

27. Row 1: normal, reversed, reversed Row 2: normal, normal, reversed
ANSWERS
Row 1: normal, reversed, reversed
Row 2: normal, normal, reversed
Row 3: normal, reversed, reversed

28. In which direction is the bus pictured below traveling?
Do you know the answer?
The only possible answers are “left” or “right.”
Still don’t know?

29. When pre-school children are shown this brain teaser, they often answer “left.” Why? “Because you can’t see the door.”
This teaser illustrates a good concept about how our memory works. Imagine if our memories were absolutely perfect. On the one hand, you might have been able to answer this puzzle correctly, since you could compare this image to all the school bus images you have in your mind, and only the ones going left would match.
On the other hand, imagine truly remembering every single detail of every single day of your life. It would be insurmountable to filter through all that data retrieve useful information…you probably wouldn’t have been able to answer the question in hours or even days, trying to retrieve and process every single bus-related memory.
Think about that next time you complain about your memory…

30. Words that are often heard together (such as salt and pepper) or words that share some meaning (such as nurse and doctor) are connected or associated in the brain. Once you hear one, the other is often activated.
Here is a brain teaser whose aim is to stimulate the connections or associations between words in your temporal lobe. You will see pairs of words, and your goal is to find a third word that is connected or associated with both of these two words.

31. The first pair is PIANO and LOCK. The answer is KEY
The first pair is PIANO and LOCK. The answer is KEY. The word key is connected with both the word piano and the word lock: there are KEYS on a piano and you use a KEY to lock doors. Key is what is called a homograph: a word that has more than one mean­ing but is always spelled the same.
Ready to stimulate connections in your temporal lobe(s)?
1. LOCK — PIANO
2. SHIP — CARD
3. TREE — CAR
4. SCHOOL — EYE
5. PILLOW — COURT
6. RIVER — MONEY
7. BED — PAPER
8. ARMY — WATER
9. TENNIS — NOISE
10. EGYPTIAN — MOTHER
11. SMOKER — PLUMBER

32. SOLUTIONS 1. LOCK – PIANO > KEY 2. SHIP — CARD > Deck
3. TREE — CAR > Trunk
4. SCHOOL – EYE > Pupil (Exam and Private are also possible)
5. PILLOW – COURT > Case
6. RIVER — MONEY > Bank (Flow is also possible)
7. BED — PAPER > Sheet
8. ARMY — WATER > Tank
9. TENNIS — NOISE > Racket
10. EGYPTIAN — MOTHER > Mummy
11. SMOKER — PLUMBER > Pipe

33. QUESTION:
Of the 100 people at a recent party, 90 spoke Spanish, 80 spoke Italian, and 75 spoke Mandarin. At least how many spoke all three languages?
Have you solved it yet? If you are working the problem, making hypotheses, testing your ideas, and coming up with a solution, you are using your frontal lobes. This is great exercise because the frontal lobes follow the “last hired, first fired” adage. They are they last areas of your brain to develop and the first to suffer the ravages of time and stress. So, keep exercising them!

34. ANSWER: 45
EXPLANATION:
10 could not speak Spanish, 20 could not speak Italian, and 25 could not speak Mandarin. So there could have been 10 people who spoke none of those languages.
However, that would maximize the number of people who could speak all three, and the problem asks at least how many speak all three. Therefore, we must assume that these 10, 20, and 25 people are all separate people. Having identified 55 each of whom is missing one language, the remaining 45 speak all three.

35. Which square (A or B) is darker?

36. Which figure should be placed in the empty triangle?
Question:
Which figure should be placed in the empty triangle?
This puzzle works your executive functions in your frontal lobes by using your pattern recognition, hypothesis testing, and logic.

37. ANSWER: 3
SOLUTION:
The top number minus the bottom left-hand number is multiplied by the bottom right-hand number to give the number inside the triangle.

38. Exercise multiple areas of your brain by trying to answer this riddle:
A blind beggar had a brother who died. What relation was
the blind beggar to the brother who died?
“Brother” is not the answer.
Now, your brain’s turn. What is the answer?
tick tick tick tick…
still working on it? …

39. The blind beggar was the sister of her brother, who died.
Explanation:
This puzzle is very simply stated and yet stumps those who have not heard it before, because the listener tends to make an implicit assumption about gender – in this case that a blind beggar is a man.
Brain Use:
This puzzle touches on being able to analyze, abstract reasoning, hypothesis testing, and assumptions residing in your frontal lobes, as well as your creativity in finding solutions to problems and emotional memory.
Answer:
The blind beggar was the sister of her brother, who died.