Why a later start to the school day could improve educational outcomes.

Schools in the UK and abroad are currently investigating the possibility that a later start to the day will actually benefit their students. But are we simply pandering to the lazy teenager? Adam Hindmarsh looks at evidence suggesting teenagers’ biological rhythms might provide clues as to why many schools are now opting for a later start to the school day.

Sixty-six percent of teenagers complain of being tired during the day as reported by their parents, this could be sleepy_teenagerbecause of having to get up early and biologically being unable to go to sleep earlier, also 15% of teenagers fall asleep during the day from lack of sleep.

Dr. Judith Owens, director of sleep medicine at Children’s National Medical Center explains that teenager’s bodies aren’t designed to sleep before 11 p.m., but they are still being made to get up around 6 or 7 a.m. meaning they are not getting the right 9 hours sleep that they should be getting, instead they are getting around 6 hours or less. Surveys into 8th, 10th, and 12th grade found that they get 7 hours or less sleep per night on week days due to having to get up early, not only does this effect the education of the children but can also put them in danger as having to get up early makes them more drowsy when driving leading to more car accidents.

Neuroscientist Russell Foster conducted memory tests on students at Brasenose College, Oxford, he found that pupils performed substantially better in the afternoon than they did in the morning. This suggests that actually their bodies work differently to an adults and actually they are biologically programmed to get up later in the day, therefore schools should open later on in the day because they need to sleep later enabling them to have the correct amount of sleep. Dr Paul Kelley, headteacher at Monksheaton High School in the UK (who has already implemented a later start)  saidevidence had shown rousing teenagers from their beds early resulted in abrupt mood swings, increased irritability, depression, weight gain and reduced immunity to disease.”, furthermore he claimed that we are the ones who are making teenagers how they are by disrupting their sleeping pattern, so to change how they are in society, we need to change how we make them get up too early, it would be like making an adult wake up at 4 a.m. every day. The peak for teenagers mental function is in the middle of the afternoon, Russell Foster said that making the start times later for the students would benefit them because they have higher cognitive function later on in the day.

Another option to starting later on in the day could be still starting early in the morning, but then just doing more simple things in the morning and more academically difficult things in the afternoon as teenagers have higher cognitive function in the afternoon. Kyla Wahlstrom of the University of Minnesota found that a teenager’s body has a late to bed, late to get up cycle, this is because melatonin, the chemical released in the brain to make you sleepy is released later on in the day, after 11 p.m. then is stopped being released later on, so at 7 a.m. they are still sleepy and the body is wanting to sleep.

All of this research and points towards the same conclusion, that the teenage body clock has slightly altered since the beginning of puberty, so this also points to the idea that schools need to open later and begin lessons later on because it means that the teenagers have higher cognitive function later in the day compared to adults because of their cycle being slightly out.

The role of pheromones in the synchronisation of the human menstrual cycle

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Martha McClintock

Is there any evidence to support the oft quoted belief that women who live together have synchronised menstrual cycles? Rachel Gilby investigates the possible role of pheromones and the research that might (but only might) offer some explanation for this curious phenomenon.

The human menstrual cycle is an infradian rhythm because it lasts for more then 24 hours. Menstruation itself occurs at the end of the cycle when the lining of the womb is shed as no eggs have been fertilised since the last menstruation. As part of the human menstrual cycle, oestrogen and progesterone, as well as other hormones, control the release of eggs from the ovary, the thickening of the lining of the uterus and then the menstruation. This cycle happens repetitively throughout a woman’s life from when she hits puberty until she reaches the menopause at around the age 50 and prepares the body for the possibility of carrying a child.

Much research has been done into how, in some cases of females all living together, there can be synchronisation of their menstrual cycle. The first notable piece of work is from Martha McClintock in 1971. Whilst at university she noticed how her and her roommates seemed to have a synchronised menstrual cycle and that this could not simply be a coincidence. She then looked at the idea that pheromones, biochemical substances that are released into the air, acting like external hormones, may play a role as they are chemical messengers that pass on messages from one member of a species to another. She took a number of female friends and dorm sharers and took pheromones from them and wiped them onto the upper lip of each other. The upper lip as it was assumed this would be the best place for them to be taken in through the nostrils and go into the body in a way that mimicked how it would do naturally in real life. She then repeated this process and found that eventually, a large proportion of women in the experiment now had synchronised menstrual cycles.

In a follow up ten year longitudinal study, in 1988, McClintock and Stern then looked at how pheromones from other women effected the menstrual cycles of women with infrequent, random, ovulation. They took 29 females between the ages of 20 and 35 with a history of irregular ovulation and gathered pheromones from 9 of them at different points in their cycles. They did this to see if they could lengthen or shorten the women’s cycles by placing pheromones from different stages of other women’s cycles on their upper lip. Their study showed that 68% responded to the pheromones with their cycles being lengthened or shortened depending on where in the cycles the pheromones they were given were from.

McClintock’s studies were both in natural settings making them high in ecological validity. The fact that the women’s lives were not altered in anyway other than by the addition of the independent variable (pheromones) and the dependent variable (menstrual cycle times) is a huge benefit as if they were put in a synthetic environment/situation this could have lead to synthetic results which are not true in real life situations. Another strength of the studies is that they could be easily replicated and that her second study continued to support and give evidence for what was found in her first study: that pheromones played a role.

As with many studies, there were also some weaknesses in McClintock’s studies. Firstly no control group was used such as looking at how much of her results were affected by the pheromones and how much was effected by the placebo effect and knowledge of the other women’s cycles. Being a quite naturalistic study that was performed over a long period of time, it was also hard for other factors to be controlled such as diet and stress levels, known to have an effect on the cycles too. The samples are also something McClintock’s studies can be criticised for, only taking into account a small amount of females with a small age range. Her original sample was hugely unrepresentative of the population, with only people in that area, of that class, with that type of lifestyle and that age range were used as they were all university students living together. The small sample size also meant that each synchronised person had a huge effect on results, how can we be sure that this wasn’t due to other causes or when their cycles were originally? McClintock’s studies also did not show significant enough results to suggest that the pheromones are the complete cause of the synchronisation of the human menstrual cycle.

Strassmann suggested that the results of the work done by McClintock may have been influenced by bias. McClintock and Stern admitted that they had made adjustments slightly to the data in order to take into account the effect of nasal congestion on the results. With the small sample size, this could have resulted in a big change in results and Strassmann responded to this by saying that ‘it would be useful to know what a priori criteria were employed in making such adjustments, and whether the data analysis part of the project was done blind’, suggesting that there may have been a lack in logical facts used in making the adjustments and that it was not done objectively, instead, the adjustments were done to influence the results and help prove the hypothesis.

The study has also been criticised for not showing cause and effect, only a correlation between the pheromones and menstrual cycles. There has been little investigation into other factors and if they have more or less of an effect than the pheromones. As with things such as heart disease, could there be a number of influencing factors?  

To conclude, the research into the synchronisation of the human menstrual cycle may not be extensive enough to give a definite indication as to what causes the synchronisation. Although there are many strengths to McClintock’s work, there are also many weaknesses and the reliability of her data is also questionable.

Does previous experience influence our perception?

Introduction

The experiment took place in order to investigate the effects of previous events on perception, in this case it was seeing a picture which was either a group of animals or a group of people and then later when shown a picture participants had to describe what they had perceived. The null hypothesis for this experiment is that there will be no correlation between the pictures that the participants were originally given and the way in which they perceived the second image. The alternative hypothesis however is that there will be a difference depending on which images were seen by the participants. The experiment was used to investigate various theories about perception such as that from Vernon 1955 who described the ‘Perceptual Set’ and said that it worked in two ways.  The first is where the perceiver has certain expectations, in this case due to the image already seen and therefore will focus their attention on particular aspects of sensory data. He calls this the selector. The second part is where the perceiver knows how to classify name and interpret certain data and therefore know what to draw from it, he calls this the perceiver.  The main aim of this experiment however is to replicate the study of perception conducted by Bugelski and Alampay who investigated the importance of expectation in the perceptual set, they found that those who had previously been shown images of animals were more likely to see the stimulus as being a rat because they had preconceived expectations. The other aim is to understand the conventions for writing psychological investigations using a simple experiment in order to practice this.

Method

In order to test this a sample involving the whole of the psychology class was taken making it an opportunity sample, some of the class were given stimulus cards depicting animals where the rest had cards with people on. This therefore used the experimental design of independent groups because there were two groups with different stimuli.  The actual picture was then put upon the board and each participant was asked to write down what they had seen. In this case it was likely to be either a man or a rat depending on the stimulus they have previously been given. The results were then interpreted using chi square which is a statistical test that allows accuracy of results to be seen.

This is the formula for chi squared:

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Here is an example of the stimuli given:

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Participants were able to give consent because it was made clear that they didn’t have to participate and could remain anonymous if necessary. On the other hand informed consent could not be given because this would affect the results of the experiment as demand characteristics could be displayed making them less reliable. A debrief was carried out however which explained why the experiment had taken place meaning the experiment was fairly ethical due to these measures.

Here is a table of the raw results seen in the experiment:

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Here is the table of the raw results inputted into the chi squared equation:

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Discussion

The results could be described using Gregory’s theory of indirect perception which states that people base their perceptions on prior knowledge and past experiences hence why the participants used their previous knowledge of the stimulus to base their perception upon. Gregory says that perception occurs as a result of hypothesis testing where the brain attempts to guess and process the image based on information previously stored in long-term memory. Here in these results however there appears to have been a fault in the perception which he would explain to be due to a faulty hypothesis hence the differing perceptions although there is still a weak correlation. So to conclude, although using chi squared the results appear to be insignificant, we can see results which begin to prove the alternative hypothesis that perception is dependent upon the stimulus seen but they are not consistent enough to provide a reliable conclusion.

A Psychology Lesson in a Box

(This review was originally featured on the BPS Research Digest blog back in 2011. I’ve updated and revised it here).

While I have been aware of products offered by Uniview for some time and have purchased a number of their DVD’s, I PsyKitFinalhave tended to produce my own resources and lesson activities. The idea of a ‘Psychology lesson in a box’, therefore, was immediately appealing and offered the prospect of reducing a teacher’s workload by offering everything that was needed for an entire lesson. The kit is certainly packed with ‘stuff’ (some more useful than others) and briefly comprises: an animated neuroscience DVD illustrating the brain’s response to nicotine, cocaine and marijuana; a brain jelly mould (presumably for making jelly in the shape of a brain); a shower cap activity kit (more later); two bags of jelly brain sweets; 12 badges displaying a brain with the caption ‘are you using yours?’; 6 brain function magnets; 3 mini neuron soft toys; 12 metal puzzles; a stopwatch; a ruler and finally a ‘scrap sack’ for an echo-location activity.

The twenty-five minute DVD (individual price £40) is very well produced – although the American narrator may confuse some students with his pronunciation of some key terms – and it includes some effective animations illustrating the synapse and neurotransmitter release. The brain jelly mould is a rather curious thing and is perhaps best filled with plaster or silicone rather than jelly. The shower cap activity kit is another curiosity. In the past I have used a baseball cap and post-it notes to carry out this activity rather than a bright pink shower cap with magnetic laminated cards. The premise is quite simple and involves students placing the cards on the appropriate part of the cap to represent the likes of localisation and brain damage. I suspect that getting one of my male students to sit with a bright pink shower cap on his head may prove problematic – but would at least liven up the lesson.

The remainder of the kit, for me, has limited appeal. Some schools have rules about handing out sweets to pupils so the jelly brain sweets could be a non-starter and I know that many of my own sixth formers would recoil at the prospect of having to wear a badge. The neuron soft toys are certainly fun and informative but students could probably do with a more detailed three-dimensional representation of a brain cell – a colleague of mine would get students to make their own three dimensional microbes which, I suspect, had a bigger impact on them.

The kit also comes with a useful CD of PowerPoint presentations and, although many teachers prefer to create their own, Screen Shot 2013-07-01 at 12.56.47these can be easily adapted to suit different student cohorts. Non-specialists could certainly benefit from pre-designed slides but I often find them too wordy to engage students fully. The ones in the kit are better than some and don’t fall into the same ‘death by PowerPoint’ scenario seen with other resources.

This certainly represents value in a monetary sense, but perhaps only because teaching resources remain so expensive. Unfortunately, much of the kit would go unused in my classroom due to the uncertainly surrounding exactly what my students would learn from them. Nevertheless, the kit is fun and would certainly appeal to teachers wishing to wind down on a Friday afternoon.

Further Details:

The AS/A2 Biopsychology PsyKit from Uniview Worldwide. Price £49 (excl. VAT)