Phobia's could be genetic!

Phobia's may occur due to our genes! 

Scared of spiders? Blame your great grandmother! Recent studies run by scientists at the Emory University School of Medicine have found evidence to the hypothesis that memories can be passed down to later generations due to genetic switches. This then allows the children to inherit these phobias which may trigger later on in their lives. 

Researches find that phobia's could be inherited from our family ancestors

New research has found that phobia's could be biologically passed down through generations. This is a cause of chemical changes that occur in one's DNA which is then later passed onto the offspring. Researchers have found that mice can pass on learned information on traumas or stressful experiences. Although these results can be linked to human behaviour we cannot 100% generalise these results to humans, however it does provide a base of a future hypothesis for scientist's to further discover. 

Thus according to these results a fear of spiders could in fact be an inherited defense mechanism used by previous generations. Dr Brian Dis says "We have begun to explore an under-appreciated influence on adult behaviour ancestral experience before conception. From a transnational perspective, our results allow us to appreciate how the experiences of a parent, before even conceiving offspring, markedly influence both structure and function in the nervous system of subsequent generations".

In the study conducted, researchers trained mice to to be afraid of cherry blossom by giving them electric shocks when exposed to the smell. The mice then associate the shock's to the small (classical conditioning). This causes the research to have serious ethical issues. In my opinion it is vile to treat animals this way for the purpose of scientific research. Anyhow, they found that the mice's offspring were also afraid on the cherry blossom compared to other odors. The following generation also had similar reactions. When analysing the structure within the mice's brains, the researchers found changes within the areas which detected the odor. This gives evidence to the hypothesis: experiences can somehow be transferred from the brain to the genome, causing them to be passed on to later generations.  

A2 level- The Circadian Rhythm

Biological rhythms: The Circadian Rhythm

A2 level revision notes

Biological rhythms are called cyclical changes in the way biological systems behave. They are controlled by: Internal biological clock (Endogenous pacemakers) and External cues from the environment (exogenous zeitgebers).  

• ·        Circadian Rhythms -the rhythms that last around 24-hours. They are physical, mental and behavioural changes, responding to light and environment in an organism’s environment. Circadian comes from the Latin ‘Circa’ (about) plus ‘dies’ (a day). The two well-known Circadian rhythms are the sleep-wake cycle and the body temperature cycle.

• ·        The sleep-wake cycle -controlled by the body’s circadian rhythms. One might think the reason you go to sleep is because of the changes in daylight. You feel sleepy when it gets dark and are awoken when sunlight comes through the curtain, or your sleep-wake cycle is based on your knowledge of what time of day it is. These are external cues called exogenous zeitgebers. However there is also an internal (endogenous) clock. This clock is free running i.e. works without external cues (exogenous zeitgebers). Sets a cycle of about 24-25 hours. In normal circumstances the internal clock does not work alone. There are external cues (daylight) which help adjust the internal clock to the environment in which you live. These studies show circadian rhythms persist despite isolation from natural light, which proves an existence of an endogenous clock. However this research also shows that external cues are importance as the clock was not perfectly accrual: varied from day to day.

• ·        Core body temperature -one if the best indicators of the circadian rhythms. Lowest at 4.30am (36c), highest at 6.00pm (38c). There is a slight trough just after lunch. Not just due to effect of having lunch- also occurs even when people don’t eat. In many countries, have an afternoon siesta (sleep in hot country) is related to this dip in body temperature. Temperature dip is a bi-daily rhythm, example of the ultradian rhythms. 

• ·        Hormones – Hormone production follow a circadian rhythm. Cortisol lowest around midnight and peaks at 6.00am. Cortisol produced when stressed but also related to making us alert when we wake up. Explains if we are awoken at 4.00am is it hard to think clearly. Because cort levels are not sufficiently high for alertness. Melatonin and growth hormones also have clear circadian rhythm, peaking at midnight. 

Evaluation

• ·        AO2 RESEARCH SUPPORT: FREE-RUNNING RHYTHM- Michael Siffre, French cave explorer, conducted a series of studies to find evidence for free-running circadian rhythms. He has spent long periods of time living underground in order to study his own biological rhythms. Whilst he was underground he had no external cue’s to guide his rhythms. (Clock, daylight, radio). He woke, ate, and slept whenever he felt like it. The only thing influencing his behaviour was his internal ‘clock’. (1^st occasion) 61 days in the Southern Alps in 1962. He resurfaced on September 17^th thinking the date was the 20^th of August! (2^nd occasion) He spent 6 months in a Texan cave in 1975. His natural circadian rhythm settled down to just over 24 hours but would sometimes change to as much as 48 hours. In 1999 he was interested in the effects of ageing on biological rhythms (60 years old). He found that his internal clock was slower compared to when he was a young man. He also found his sleep patterns had changed. His study was supported by other studies: Aschoff and Wever 1976, Place participants in underground WW2 bunker. No environmental and social time cues. Found more participants displayed circadian rhythms between 24-25 hours. Some were as long as 29. This shows the cycle operates in the absence of external cues and natural free running cycle is about 24-25 hours.
• ·        AO2 RESEARCH SUPPORT: IMPORTANCE OF EXTERNAL CUES- Folkard 1985 conducted an experiment to see if external cues could be used to override the internal clock. 12 participants lived in a cave for 3 weeks, no natural light and other time cues. They agreed to go to bed when clock indicated 11.45pm and get up when indicated 7.45am. Initially the clock ran normally but gradually quickened until it was indicating passing of 24 hours when only 22 had passed. Beginning: circadian cycle matched the clock. When quickened their rhythm ceased to match the clock and continued to flow a 24-hour cycle rather than the 22 imposed by the experiment. (Apart from 1). Conclusion: Circadian rhythm can only be guided to a limit extent by external cues. As soon as experiment was over participants took days to resynchronise their cycles to the available external time cues (clocks, daylight). Showing influence of external cues.
• ·        AO2 SLEEP WAKE CYCLE: METHODOLOGY- Early research suffered from a flaw, when estimating the free running cycle. Participants were isolated from variables such as clocks and daylight. However they were not isolated from artificial light. It was thought that dim light (contrast to daylight) would not affect the circadian rhythm. Recent research shows this may not be true. Czeisler et al 1999 altered participant circadian rhythms down to 22hours and up to 28 hours just using dim lighting.
• ·        AO2 SLEEP WAKE CYCLE: INDIVIDUAL DIFFERENCES- 1) Cycle length. Czeisler et al 1999 found circadian cycles in different people can vary from 13-65 hours. 2) Cycle onset. Individuals appear to be innately different in terms of when their circadian cycles reaches their peak. Duffy et al 2000 found morning people prefer to rise early and go to bed early (6am-10pm). Evening people wake and go to bed later (10am-1am).

Serotonin may trigger Phobias!

Too much serotonin may trigger social phobias

Feeling good may have side effects!

Recently it has been noted by psychologists that levels of the chemical serotonin are too high within people who have social phobias. Researchers at the University of Uppsala in Sweden have conducted brain scans on volunteers who have social phobias, such as anxiety. They found that they had produced too much serotonin in their amygdala. The amygdala is a part of the brain's fear center. 

The more serotonin produced within the volunteers the more anxious they felt when exposed to social situations. Researcher Andreas Frick has stated that "Serotonin can increase anxiety, and not decrease it as was previously often assumed".  

What exactly is serotonin? Well, serotonin is a neurotransmitter in the brain which is responsible for regulating brain functions such as mood, appetite and sleep. They are commonly known as the "feel good factor". They are released when one has chocolate. Serotonin is produced by nerve cells and helps to relay message from one side of the brain to the other. 

There has been previous research studies which also show a positive correlation between the amount of serotonin and the levels of anxiety. They have shown that nerve activity in the amygdala is higher in people with social phobia. Furthermore is has been found that the fear centers within their brain are overly sensitive. This is said to be due to the high levels of serotonin. 

To this day social phobias have been treated with drugs such as selective serotonin re-uptake inhibitors. This increases that amount of serotonin in the brain. Must these treatments be changed due to the recent findings of serotonin and social phobias? And what exactly do these finding mean to us. Must we lower our serotonin production? Should we stop eating chocolate?... I hope not. 

Food and Mental health

Recent studies have shown a possible link between food and social anxiety problems. Such types of foods being fermented foods, which have probiotics. This study is the first in its time that psychologists have decided to take the research further and continue exploring the connection between the mind and the stomach.  They will proceed by examining the data again to see whether there is a correlation between fermented food intake and autism symptoms. Although, this approach may not be valid, as it is difficult to establish a cause and affect of the data using correlation. However, correlation research has been deemed ethical as it enables the researchers to manipulate variables which would be unethical to manipulate in an laboratory setting.

Recent studies led by William and Mary researchers shows the stomach may play an important role in our mental health. 

Psychology professors have recently investigated a possible connection between fermented foods (which contain probiotics) and social anxiety. They found that young people who eat fermented foods have fewer social anxiety symptoms.

The researchers designed a questionnaire which was giving in the University of Maryland's introduction to Psychology, 700 students participated. The questionnaire asked students to detail the fermented foods they had consumed within the last 30 days. It also inquired about amount of exercise and their average intake of fruits and vegetables. This enables the researchers to take into account some external variables other than just fermented foods.

Within the first set of findings they found that students who ate more fermented foods had reduced social anxiety (show by neuroticism). The relationship was strongest amongst people who has higher levels of neuroticism.

The researchers are set to create an experimental version of the study in order to establish a cause and effect between eating fermented food and reduced social anxiety.

In conclusion the study is some what reliable, however, disadvantages would include the use of questionnaires as participants may fake their answers due to social desirability. Further more the study was only used on people of the same age group (University students) causing the study to lack population validity.

Introduction

Welcome all psychologists!

My name's Sindhu and I'm currently studying A2 level psychology and wish to continue the subject at University. The purpose of this blog is to share with you interesting information, as well as being a useful revision tool for all students who are also taking the subject for A2.

Enjoy!