Category Archives: Developmental Psychology

Inspiring People: Savants

Savants have always been interesting to the scientific community because of their ability to overcome so many odds. The large majority of savants struggle with some form of mental handicap may it be social or intellectual. Yet, despite these struggles most savants reach a level of genius and expertise far beyond what is considered normal human capacity. One savant that we all probably have at least heard of is Rain Man, who was inspired by a real life savant Mr. Kim Peak who sadly died in 2009.


The different kinds of Savant syndrome can be categorised as Splinter Skills, Talented Savants and Prodigious Savants. Splinter skills is when a person has specific skills that stand out compared to their normal level of functioning (Hiles, 2002). Talented savants is when the individual has a high level of ability  compared to a disability, and prodigious savants, the rarest of them all, is when a person has a level of brilliance not only compared to their normal functioning but compared to human capacity (ibid). It is important to note that that even though Savant syndrome is the official name, it is not considered a disorder by either DSM-IV-IR or ICD-10.

Stephen Wiltshire 

In the news recently is Stephen Wilshire, another autistic Savant. Stephen Wilshire (2013) spent his childhood as a mute, not speaking until around the age of 9. He pretty much relied on his artwork to communicate with anyone, even his family. Today, however, Wiltshire has risen above his handicaps, and now owns his own gallery in in London’s Royal Opera Arcade that feature his amazing artwork. What draws people to his artwork, however, is not just his admirable artistic talent but also his incredible memory for fine detail. Wiltshire is able to draw the most incredible architectural detail having only seen the building for a couple of seconds. An incredible YouTube video shows Wiltshire flying over Rome in a helicopter just once to then return to a studio and draw an awe-inspiringly accurate panorama of the beautiful city.



The Twins 

The Twins, two brothers featured in Oliver Sack’s 1985 book The Man Who Mistook his Wife for a Hat, were both severely handicapped with an IQ of 60. Despite being terribly bad at simple calculations and the basic concepts of multiplication and division, the brothers were still able to communicated with each other through numbers. Even more astounding was their ability to memorize 300 figure digits, knowing if a number up to 20 digits was prime, and to know any day of the week 40 thousand years into the past and future!


Daniel Tammet 

Lastly, Daniel Tammet is an autistic, prodigious savant known to most of the world for the week it took him to learn Icelandic. Despite being socially handicapped, he is considered gifted in mathematics and language learning, holding the European record for reciting the digits of pi. Unlike the other three, Tammet is considering high-functioning on the autistic spectrum, but despite this his incredible mathematical and linguistic ability is far more advanced that normal. Professor Alan Synder of the Australian National Universtiy compared Tammet to the Rosetta Stone because unlike Savants, he is able to explain the processes going on his brain and mnemonic devices he implements. Research conducted by Cambridge Professor Simon Baron-Cohen et al. in 2005 discovered that Tammet has synesthesia and incredible short-term memory. Baron-Cohen et al. suggests that the combination of his synesthesia, incredible short-term memory, Asperger’s and his use of mnemonic strategies is what enables him to have such an immense capacity for learning.



NICHOLSON, R. (2013). Referencing and citation – Harvard style, from PSY106 Memory, Skill and Everyday Life. University of Sheffield, Richard Roberts Building on 6th March. Available from: Blackboard.

The Sleep Cycle

Sleep is a confusing topic of study because despite every human needing it, no one really knows with 100% certainty why we do it. There is no single theory that is accepted by the entire scientific community; however, two main hypotheses seem most fitting. First, the restoration hypothesis proposes that we sleep to rest and recover, a preparation for when we wake. What is being restored remains unclear. The second hypothesis proposes that sleep is an adaptive process that keeps us out of trouble for a large chunk of the day: hiding us from predators and conserving our energy reserves. The only thing we do know about sleep is that we cannot survive without it.

The Stages

The majority of our sleep (75%) is spent in non-REM (rapid-eye movement) sleep and occurs in four stages. An entire sleep cycle takes approximately 90 minutes and is classified as a form of ultradian rhythm (faster than circadian which is a 24 hour cycle).

Stage 1: The Transitional Stage

Stage 1 is known as the transitional stage as it is when our brain waves become less regular and begin to wane. If you were to look at an EEG we would pretty much look wide awake. You have probably felt the sensation of shifting between the two stages if you have ever fallen asleep in class or in front of the TV. That sense of falling is due to the slowing of our brain waves. Activity levels begin to change from alpha to theta waves; they are high amplitude but very low frequency. Due the small difference, however, stage 1 is the lightest stage of sleep and we are easily woken. Our eyes are making slow, rolling movements and the whole stage only lasts a few minutes. All in all though, it only occurs at the beginning of sleep and only lasts 5-10 minutes.

Stage 2: The First NREM Stage 

Stage 2 marks the true beginning of non-REM sleep. During stage 2, our brain waves become slightly deeper and occasional variations in wave movement (oscillations) occur between 8-14 Hz occurs. These oscillations are called sleep spindles and are produced by thalamic pacemaker cells.  It is proposed that sleep spindles occur because the brain is trying to inhibit processing to ease the transitional into sleep. Another characteristic stage 2 indicator is the K-complex. K-complexes are a high-amplitude, sharp wave and the largest brain event during sleep. Scientists believe that K-complexes help suppress arousal and aid in memory consolidation. Lastly, another indicator of transition from stage 1 to stage 2 sleep is that eye movements cease.

Stage 3 and 4: The Delta Rhythm Stages 

During stage 3, an EEG would show large-amplitude, low rhythm delta waves. Eve movements as well as body movements will be usually be absent. Stage 3 can also be seen as a transitional stage but between light and deep sleep. As we enter into deep sleep our body and brain become increasingly less sensitive to stimuli and less susceptible to arousal. Common childhood sleep issues such as bed wetting, night terrors and sleep walking tend to occur towards the end of stage 3. The main difference between stage 3 and 4 is the amount of delta waves. When less than 50% of deep sleep is delta, we are in stage 3. When more than 50% of our brain activity is delta waves, we are in stage 4 of sleep. As delta waves correspond with very deep sleep, a person in stage 4 of sleep is the hardest to wake. This can be extremely scary if a person is sleep walking or a child is having night terror. They may seem awake but they are completely unresponsive to external stimuli. Stage 4 of sleep only happens during the first cycle as such, our sleep becomes lighter throughout the night. This is extremely helpful as it prepares our body for waking. From an evolutionary stand point this makes sense. Our ancestors certainly could not set an alarm clock, the noise of other animals and the rising sun needed to be sufficient to wake us.

REM Sleep 

REM sleep is probably the most exciting and important of all the stages of sleep. REM stands for rapid eye movement and is suitable name for this stage as an EOG would show rapid eye movement under our eyelids. During this phase we also experience dreaming. Our brain activity mimics waking, showing a myriad of different brain waves: alpha, beta and dysynchronous waves. Despite our brain activity showing an incredible change in activity, our muscles are actually paralysed. A scary albeit common phenomenon known as sleep paralysis is when we wake-up during REM sleep and our muscles remain effectively paralysed.  During sleep however, this “paralysis” is known as sleep atonia. It is a beneficial process as it prevent us from acting out our dreams and putting ourselves in harms way. Certain neurons in our brain stem (specifically the tegmentum) known as REM sleep-on cells release monoamines inhibit motor neuron activity. Another curious attribute of REM sleep is the incredible recall of a person woken from it. Our dream world becomes as real and vivid as the real world. As REM mimics wakefulness, waking someone during REM means they will feel very alert. The exact reason for REM sleep is as elusive as sleep itself; however, scientists do know that like sleep, it is vital. When a person is repeatedly disturbed during REM sleep or does not get enough sleep in general, we go through a process called REM rebound. In other words, we spend the majority of our following sleep in REM. Lastly, scientists have also discovered that newborns and foetuses spend the majority of their sleep in REM. All in all, these findings suggest REM is vital to proper human functioning and development.

In Conclusion 

As we progress through the night we spend increasingly less time in stages 3 and 4. After the first cycle stage 1 of sleep is replaced by REM sleep and the amount of time spent in REM sleep increases. Even though the reason why we sleep is unclear, the change in brain activity and the determent of not sleeping is enough to say with certainty that sleep is necessary for normal human function.


Bear, M., & Connors, B. (2007). Neuroscience: Exploring the brain (3rd ed.). Philadelphia, PA: Lippincott Williams & Wilkins.

Dement, W.C. (1978). Some must watch while some must sleep. New York: W.W. Norton.

Hall, R. (1998, January 1). Stages of Sleep. Retrieved September 14, 2014.

K-complex. (2014, August 24). Retrieved September 14, 2014, from

Pinel, J.P.J. (1992). Biopsychology. Needham Heights, MA: Allyn & Bacon.

Sleep spindle. (2014, August 24). Retrieved September 14, 2014, from

Methods Used for Studying Infants’ Perception

Part of getting onto a good masters or Ph.D programme means having real-life experience. As only a second year undergraduate that can sometimes seem like an age away, but time really does fly by. In order to get some experience in research I transcribed videos for a developmental researcher at my department. Even though my job was pretty menial in the whole scale of things, writing down all the speech and movements of infants really made me appreciate something substantial; infants are very hard to understand and observe. Their intentions, their desires and even just their knowledge can be difficult to interpret. As such, psychologists use a set of methods to study infant perception, intentions, desires and capabilities.


This post will deal with studying infant perception.

Preference Technique 

Basic set-up

1. A researcher presents two stimuli to an infant simultaneously

2. The researcher monitors the infant’s eye movement. Researchers use various techniques for this, one being the ASL Model 504.

3. If the infant looks more at one stimulus than the other, it is inferred that the infant prefers that stimulus over the other.

If accurate, measures of the eye movements can be made, this technique is quite simple and effective. The infants preference can be inferred because of habituation, a fancy word for boredom.


Habituation and dishabituation are another method used to study infant perception and preference. After looking at a stimulus for a certain amount of time, we become bored of it. Just like after awhile we stop feeling the clothes on our body. Our brain gets bored with the touch sensation, and so eventually it stops informing us of it. On this basis, psychologists infer that babies will stop looking at a stimulus if they gets bored of it. If a stimulus is then presented with a new stimulus, it is likely he or she will prefer looking at the new stimulus that the infant has not seen before. If the infant does prefer the new stimulus, we can infer that the infant is capable of discriminating between the two stimuli. Discrimination between two stimuli allows researchers to detect the stage of perceptual development of infant has reached.


Classical and operational conditioning are terms you should be familiar with have you ever taken an introductory psychology course. Conditioning with infants consists of the same learning system. Fortunately, infant studies usually just involve rewarding the infant with pleasant sounds or images, usually of or from their mother.

Basic set-up

1. Infant is given a dummy or pacifier

2. Researcher waits for the infant to begin sucking on it at their usual rate

3. If the infant begins sucking at a faster rate than usual they are rewarded with the sound of their mothers voice

4. The infant will soon learn that as long as her or she continues sucking at the increased rate, they will hear their mother’s voice

5. After awhile, habituation sets in as the baby loses interest in the sound and their sucking rate decreases

6. The researcher then proceeds to introduce a new sound

7. If the infant is capable of discriminating the new sounds, they will begin to suck more again to her this new sound


All of these various tests of perception, as mentioned above are used to measure the development of infants.