Have you ever wondered what the world would be like if Mary-Kate and Ashley Olsen were actually identical twins? Are identical twins more similar to each other in intelligence than fraternal twins due to their genetic makeup? Before we delve into this further, we should define what are identical and fraternal twins first.
Identical twins, also scientifically referred to as monozygotic twins, occur when 2 offspring are developed from one single egg.
Fraternal twins, also scientifically referred to as dizygotic twins, are 2 offspring that are developed from 2 separate eggs.
Some very useful research techniques developed by psychologists, employed the use of twin studies and adoption studies to a have a better understanding of genes and heritability. With twin studies, psychologists were able to compare intelligence differences between monozygotic twins and dizygotic twins. Their findings revealed that monozygotic twins are more similar in intelligence (correlation of 0.86) than dizygotic twins (correlation of 0.60). Furthermore, by looking at the adoption studies, we see that monozygotic twins remain alike whether they are raised together (correlation of 0.86) or raised apart (correlation of 0.78). With this data, we can make an argument that genetics has a greater influence in the intelligence of identical twins than the environment.
Afterimages are images that remain in one’s vision after its initial exposure is gone. If you were to stare at the above afterimage for 30 to 60 seconds and then look at a blank white screen you will see a clear picture of Jesus. There are 2 main things that cause this type of effect. The first is the adaptation in the firing rate of ganglion cells in the retina. When ganglion cells become excited or unexcited for a long period of time, they produce a rebounding effect, firing these ganglion cells at a faster or slower rate than normal. The second reason for this occurrence is because of the eye’s photoreceptors, mainly the cone cells, becoming over stimulated and then desensitized or fatigued.
Ambiguous Illusions
What do you see in the image above? Is it 2 faces or a vase? These ambiguous illusions are determined by the way each individual perceives shapes and edges. When we view the world, we categorize most of what we see as either an object or a background. Psychologists define these terms as figures and grounds. Depending on how we look at things, objects can be seen as backgrounds and vice versa. For example, if we were to focus our eyes on the inner curved edges of the image, we would see the white vase as the object surrounded by a black border. However, if we were to view the curved lines in an outward fashion, we would see 2 faces as the object in front of a white background.
Illusions of Depth
The Ponzo illusion is an optical illusion that plays with the idea of depth. The top line appears to be longer than the bottom but in reality both lines are the same length. Our mind sometimes determines the size of the object based on distance and the surrounding background in which it is placed. In this example, the two converging vertical lines represents as a background for a railway track. The way these lines are angled and converge creates what psychologists call a linear perspective. This produces a sense of depth or distance in our visual field and that is why the upper line looks longer than the bottom.
Illusions of Colour and Brightness
The squares “A” and “B” are the same shade of grey. Don’t believe me? Put this image into Photoshop and extract the colours from both squares and you will see that I’m right. This optical illusion is commonly known as Adelson’s checker shadow illusion or the same colour illusion. The discrepancy of grey cast by the cylinder’s shadow and the lighter greys outside of the surrounding shadow, makes our eyes compensate for the colour contrast giving the illusion that the 2 squares are completely different shades.
Solomon Asch, a well known Gestalt psychologist, was interested in looking at social pressure or conformity in groups and what it does to human behaviour. He eventually came up with an experiment known as the Asch Paradigm in the 1950s. The experiment was simple. Participants were asked to look at 3 vertical lines on the right and find out which of these lines is the same length to the line on the left. When these trials were done individually, 99% of participants provided the correct answer. However, in a group setting, the accuracy of correct responses dramatically decreased. The group experiment is set up as follows. The experimenter takes a cluster of people and lines everyone up. You, the participant, are placed at the very end of the line. The trick here is that there is only 1 participant in the room and everyone else are confederates. These confederates pretend to be participants but are actually in on the experiment. The experimenter then goes down the line and asks everyone for their answer. All of the confederates purposely give the wrong answer. When it is the participant’s turn to reply, 75% of people would agree with everyone else in the room, even though they know it’s the incorrect answer.
Why do people give into peer pressure? Humanistic psychologist, Abraham Maslow, explains this in his theory of Hierarchy of Needs. Maslow’s theory can be visually represented as a pyramid. The third tier on the pyramid is our need for attachment. Maslow believes that this is an important need as it helps create self-esteem. People need to a have a sense of belonging. This feeling of acceptance and being valued by others is also defined as conditions of worth by Carl Rogers. This may be the reason why contestants on the show were more likely to listen to the audience.
Uncertainty
When faced with a difficult task, we are often more likely to ask others for advice. Solomon has tested many variations of the Asch Paradigm, one of which was by increasing the level of task difficulty. He did this by making the differences of line length smaller. He found that these tasks produced a greater amount of conformity among participants. Game show contestants may have made their decisions by listening to the audience because they were unsure of what to do.
Reward
What if contestants were playing for something on the show? Going back to Maslow’s Hierarchy of Needs, the simple answer for the contestant’s actions may be because they need the prize money to purchase a home or pay off debts. This is related to tiers 1 and 2, which are physiological needs and safety needs.
Another reason that can tie into this is operant conditioning. This is a form of learning devised by Burrhis Frederic Skinner, where behaviour is affected by its consequences. The behaviour exhibited by the contestants is known as positive reinforcement, where the frequency of an action increases when it is followed by a positive outcome. In this case, contestants are more likely to shock players if they receive positive feedback such as cheering from the audience or an increase in prize money.
A new reality game show takes a page from one of social psychology’s most famous and controversial research, known as the Milgram experiment. During the 1960s, Yale University psychologist Stanley Milgram, wanted to study the effects of obedience to authority and see if it played a part in the Nazi Holocaust. The study involves the experimenter, ordering the teacher (participant) to administer incremental 15 volt electric shocks to the learner (victim) every time he or she gives a wrong answer. The teacher believes that the learner is receiving electrical shocks. In actuality, there were no shocks. Being that the teacher was unable to see the learner throughout the experiment, pre-recorded sounds were used during shock trials to simulate the learner’s cries of pain. The results that Stanley gathered found that every participant shocked up to at least 300 volts and 65% went to the maximum of 450 volts.
In the French game show, Xtreme Zone, the roles of the experimenter are reversed. Instead of the authority figure giving the orders, contestants are encouraged by the audience, to give “painful electrical shocks” to players as punishment for incorrectly answering a question. Astoundingly, 81% of the contestants shocked players at the game’s maximum 460 volts. There was no prize to be won on the show so contestants were doing this without any reward or incentive. How could anyone come to perform these horrible acts? There could be several reasons of which will be explained in part 2 of this post.
The sensory homunculus is a physical representation of the somatosensory cortex. The word homunculus comes from the latin word “little man” and in psychology is referred to as the “little man inside your brain”. A homunculus has oversized lips, hands, feet, and tongue with skinny arms and legs. The somatosensory cortex is found within the parietal lobe behind the frontal cortex where it processes touch sensory information. The homunculus’ body is scaled according to the amount of cortex it is devoted to it. For example, the homunculus’ large hands represents an extensive proportion of touch receptors within the somatosensory cortex, meaning our hands are a lot more sensitive to touch than the rest of the body. Each body part’s location on the somatosensory cortex can also be topographically projected as seen in the top left image above.
Dr. Wilder Graves Penfield, an established neurosurgeon, was the first to map out the brain’s sensory and motor cortices through neural stimulation. The idea for mapping the cortex was first discovered during his treatment of epilepsy patients, where he used electrical probes on conscious patients to pinpoint and remove seizure causing nerve cells in the brain. He was inducted into the Canadian Medical Hall of Fame in 1994 for his achievements.
Show us a drawing of your homunculus and post it in the comments below!
Frontal Lobe
-located in the front of the brain
-the frontal lobe begins at the anterior and continues in a posterior direction until it reaches the central sulcus
-major function is controlling motor movement
-also controls inappropriate behaviour
-the most anterior portions function to plan muscle movement and daily activities
Parietal Lobe
-begins after the central sulcus and continues in a posterior direction until it reaches the occipital lobe
-major function is to receive sensations from the body
Occipital Lobe
-begins after the parietal lobe and is the most posterior lobe
-major function is vision
Temporal Lobe
-located ventral to the sylvian fissure and anterior to the occipital lobe
-major function is hearing and speech
Cerebellum
-located dorsal to the pons and medulla oblongata
-major function is for sensory motor control including posture and balance
Pons
-located superior to the medulla oblongata
-major function is to relay information between the cerebrum and cerbellum
-also plays a part in respiration, sleep, and motor control
Medulla Oblongata
-located inferior to the pons and anterior to the cerebellum
-major function is to regulate basic life processes including heart rate, blood pressure, and respiration
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