Assignments 12 (05Feb2013) Method
Method and Design
This study is an experimental study because a variable will be manipulated, and it will be carried out in lab conditions as access to scientific equipment such as the fMRI scanners is necessary.
The independent variable is the video game.
The dependent variable is the aggression.
Participants
Random sampling of 44 male year 12 and 14 students. The study will only include males to reduce variables which could impact the data (for example comparing boys and girls)
22 participants will be randomly assigned to playing the violent video game, and the remaining 22 will play the non-violent video game
Materials
– fMRI scanners
– video games (one violent and one non-violent)
– video game console and screen to play on
– 2 sets of questions
– there will be 2 sets of questions (set A and set B)
– the participants will be split into 2 groups (group 1 and group 2) each with 22 of the participants
– group 1 will be asked set A before playing the video game, and set B after playing the video game
– group 2 will be asked set A after playing the video game, and set B before playing the video game
– a voice recording of the questions, so each question is asked in exactly the same tone of voice to each participant
– a scale of colours from the fMRI scans, each colour with a number.
The Questions
The questions that are asked must all be as equally provoking. For example a question could be “how would you respond to somebody punching you for no reason?”. It must be taken into account that some questions may provoke some PPs more than others, for example if a topic was particularly sensitive it would provoke more aggression, which isn’t relevant to the study, because the first set of scans especially are to get a feel for how aggressive the PP is normally.
Participant Instructions
22 of the participants (PPs) will be randomly assigned to playing the violent video game, and the 22 remaining will play the non-violent video game.
-Participants will not be told which they will be playing.
Then, 22 PPs will be randomly assigned to being in group 1 or group 2 (whether they are playing the violent game or not has no effect on this grouping).
Group 1 will have scans taken of their brains individually, while being asked set A questions.
Group 2 will also have individual brain scans, however they will be asked set B questions.
– These scans are necessary so the researchers are able to compare and measure the activity in the pre-frontal lobe before the gaming and after.
After having these first scans, each PP will go on to play either the violent video game or the non-violent video game.
Gaming will go on for 30 minutes per PP, and then after gaming each PP will have another scan.
Group 1 will now be asked set B questions and group 2 will now be asked set A questions while having their second fMRI scan.
Operationalisation
The researchers will look at the colours of the brain, particularly the pre-frontal lobe on the fMRI scans to measure activity. The colours that appear on the scan, will then be compared to the colour scale. The same person for all 44 PPs will decide which colour on the monitor matches which colour on the scale. Once this has been decided, the researcher will note down the colour’s number so then later findings can easily be produced in a graph.
Ethics
– exposing possible underage children to explicit content
– take informed consent from underaged PPs parents.
– possibility of psychological harm therefore every PP should be thoroughly debriefed and counselling should be offered if necessary.
– ask non-participants the questions to see if there is a risk of psychological harm/ OR give to parents
– deception
Assignment 11 (28Jan2013)- Introduction
Media exposure can cause psychological harm to those exposed to it. Researchers have found that playing video games can cause the brain to function in a different way, particularly the pre-frontal lobe. It is thought that there is a decrease in pre-frontal brain activity when playing violent video games compared to playing less violent video games. Video games have also been linked to aggressive or angry behaviour, and there have been many studies carried out to support these views.
Matthews et al 2006 tested this hypothesis in a study looking at 44 male adolescents who played either a violent video game (Medal of Honor) or a less violent, but still entertaining game (Need for Speed). Immediately after playing the games, all of the participants had fMRI scans to measure pre-frontal lobe brain activity. This study found that there was a reduction in reactivity in the pre-frontal lobe as originally thought.
However, this study can’t be generalised because it was only conducted on adolescent males, and that sample group isn’t only gender biased, but it is also not representative of society as a whole. Also, it has been called unethical because it is exposing potential underage participants to content they are perhaps not mature enough to deal with as Medal of Honor is rated an 18+ game. This could have led to psychological harm with the participants.
Recent meta-analyses have demonstrated that playing violent video games can increase physiological arousal and anger (Anderson et al 2004). Therefore, this shows that a consequent of playing violent video games is that aggression is increased through increased physiological arousal.
However, there has been evidence provided that video games and exposure to the media has no effect psychologically. The Byron Review of 2008 shows there is no link between playing video games and aggressive behaviour. Byron concluded that there is no hard evidence of desensitisation or any other form of psychological harm due to playing video games.
All of these studies support either one of the views that video games/media exposure can cause aggression or psychological harm to those who play them. However, the Byron review rejects these hypotheses by presenting the idea it isn’t the video games causing the problems.
Formulation of aims
The aim of this study is to replicate Mathews et al’s study on the effect of video games on the activity in the pre-frontal lobe. However, instead of doing fMRI scans just after playing the games, scans will also be done before hand in order to provide some comparison. Another change that will be made is that there will be a recording of some provocative questions or statements played to the participants during the scans to see if any aggressive behaviour is triggered more or less due to the video games.
Statement of alternative hypothesis
After playing a violent video game, an adolescent has a significant decrease in pre-frontal brain activity compared to an adolescent who played a non-violent game.
Statement of null hypothesis
After playing either a non-violent or a violent video game, there will be no effect on the activity in pre-frontal lobe of the brain.
Blog Assignment 4 (30/09/2012) ‘Outline and evaluate evolutionary explanations of food preference.’
- The Environment of Evolutionary Adaptation- it is the environment to which a species is adapted. Animals that lived in different environments or made their livings in different ways faced different reproductive problems, and that’s why all animals aren’t the same.
- The EEA is involved with our eating behaviours in the way that we have had to adapt from hunter gatherer times. For example, cooking. The hunter gatherers didn’t cook as they didn’t know to; they didn’t know to make fires to cook food so their bodies were prepared to eat raw ingredients, even meat. They would know the good foods from the bad foods purely through trial and error, as there was no way of knowing of foods that could kill. However, modern day we cook our foods. This is because our bodies have adapted to not be able to handle raw meats, and it could kill us so we cook to survive. Now it is completely normal and expected to cook foods, and would be out of the ordinary if we didn’t.
- Humans have a preference for sweet foods because in the hunter gatherer times, they knew foods such as berries and fruits were ripe, and more importantly, safe to eat if they were sweet. Also, because it is the sweet foods where energy is gained from- carbohydrates. However, nowadays our sweet tooth doesn’t make us crave fruits or berries, but sweets and cakes etc.
- We eat meat because this is where we gain a lot of protein and calories, and hunter gatherers would have used this energy from calories to hunt. Also, it would have been a lot quicker to hunt an animal, than to forage for hours looking for safe fruits. Humans developed intelligence, which is how they learned to hunt; they would make tools and work as a group, which then lead to social skills, and therefore language. Hunter gatherers would eat the meat for the protein as this contributed to the growth of the brain in humans. The men who hunted the most meat were deemed the most attractive to women as they were intelligent, and would be able to provide for a family.
- A study to support these ideas is………………………..
- A study to challenge these ideas is………………………..
- Deterministic the philosophical principle that every state of affairs, including every human event, act, and decision is the inevitable consequence of antecedent states of affairs. (http://www.thefreedictionary.com/deterministic) This then means that our eating behaviours are pre-disposed, and free will has nothing to do with it. Reductionist is an attempt or tendency to explain a complex set of facts, entities, phenomena, or structures by another, simpler set (http://www.thefreedictionary.com/reductionist)
- Evolutionary theories can be thought of as deterministic in the sense that eating behaviours have been inherited from our ancestors. They learned to cook food, so now humans don’t even think about cooking foods, the just do it. Some foods they have no choice but to cook because if not they will not survive. So in this sense, eating behaviours are deterministic due to evolution.
- Evolutionary theories can be thought of as reductionist in the sense that………
- Non-falsifiable means that a theory can not be proved wrong. It is impossible to disprove it, so therefore it is ‘non-falsifiable’.
- Evolution is non-falsifiable because there is no way anybody can get evidence to prove its wrong. There are theories that may argue against it, but it is impossible to collect evidence which would prove it 100% wrong.
Neural mechanisms involved in controlling eating behaviour.
The ‘dual control mechanism’ as part of the glucostatic theory.
Eating behaviour is regulated by:
–fat stores (lipostatic hypothesis) and
–glucose levels (glucostatic hypothesis)
The ‘Dual-Centre Theory’ is made up of 2 parts: the ventromedial hypothalamus (VMH) and the lateral hypothalamus (LH). The VMH is like the ‘satiety centre‘ which means this is where fullness is detected and therefore tells the body to stop eating. When the glucose levels are increased, i.e. after eating, then the VMH is activated, achieving satiation (the feeling of being full.) When the eating has been stopped for too long, and the blood glucose levels have dropped, the LH (the ‘hunger centre‘) detects this change and is activated. This makes the body feel hungry, and ghrelin is produced. This is a hormone, and is the familiar rumbling sound stomachs make when an individual is hungry, and is basically the body wanting glucose levels to be increased, and this is achieved by eating.
Every individual has a set point, and their weight is regulated by the set point which is determined by the hypothalamus. The body will maintain this weight as it is practiacally ‘programmed’ into the body.
Karl Lashley was one of the first psychologists to suggest eating behaviour is linked to the brain and isn’t just a reflex.
He used rats to support his growing belief that neural mechanisms are involved in decision making. He cut out different areas of the brain to see the effect on their ability to negotiate a maze successfully and reach the food placed at the exit as a reward. Rats who VMH has been lesioned developed overeating and obesity.
He discovered how vital the role of the hypothalamus is in playing a part in the regulating of food intake. In particular, the LH was identified as the main hunger centre and the VMH as the main satiety centre.
Evidence for the Dual Process
Research from the 1940’s onwards has been done on animals. It has shown that lesioning areas of the LH in rats, dogs and other animals led to a loss of interest in food and eating, and the animals seemed to be unaware of the fact they were denying their bodies food, therefore starving themselves.
However, Gold (1973) found that lesions restricted to the VMH alone did not result in hyperphagia (overeating) and only produced overeating when they included other areas such as the parvoventricular nucleus.
Evaluation
– These studies are dated, and therefore may not be relevant or contain useful up to date information.
– We can’t generalise for rats to humans. Having different brain structure may mean different things would happen to rats and other mammals than would to human beings.
+ They contain good empirical evidence, therefore isn’t based on just theory.
+ They are still influential and still relate to and support other studies.
The role of leptin (lipostatic theory) in eating behaviour.
Leptin is a hormone, and acts upon various hypothalamic areas and seems to inhibit the release of another neurochemical called neuropeptide Y (NPY) This is the neurotransmitter stimulating hunger and eating behaviour.
Leptin is secreted -> hypothalamus is signalled: calories are high enough -> body ceases to release fat cells -> hypothalamus detects this drop therefore equalling the feeling of hunger.
Ravussin et al (1997) conducted a longitudinal study and investigated the Pima Indians, a population prone to obesity.
Two weight-matched groups were studied over 3 years and it was found that mean plasma leptin concentrations were lower in the group that gained weight than in the group that did not
Explanations for the Success and Failure of Dieting
Denial
This is where people deny their bodies certain foods in order to diet. However, due to impulses the body ends up craving the food more.
The theory of denial holds that any intentional control of the mind introduces an operating process that directs the conscious attention focusing of our minds on positive thoughts. This process is accomplished by an ironic monitoring process that looks for the failure of our intention. Such monitoring can, when we are stressed or under mental load, actually promote the unwanted mental state.
Wardle and Beale (1988)
– To investigate whether diets lead to overeating.
– Assessed food intake at 4 and 6 weeks, Participants randomly assigned to diet group, exercise group or control group.
– Study was conducted on 27 obese women.
– Those who were ‘dieting’ ate more than those exercising.
– Experimental design, which means manipulation could take place.
– Random allocation to participants.
– Lab conditions- high control
– Small sample size
– Lacks ecological validity.
Restraint Theory
This is where people restrain what they eat so they can diet but end up overeating.
Wardle and Beale’s reasons for overeating:
– Counter regulation. Eating more after a high calorie intake.
– Disinhibitant. Eating more because they’re being less strict on themselves.
– The ‘What the Hell’ effect. Individuals decide its ok to break the diet more so if they’ve already broken it.
When restraining food the individual has to overcome impulses cognitively.
‘Cognitive Boundaries’ this is how much a person can eat before feeling full.
Process of restraint battles with ‘biological rhythms’.
Hermen and Mack 1975
– Gave participants a pre-load food either high or low calorie.
– Participants are left alone to do taste test in own time.
– Key factor- they know how much they eat.
– Dieters ate more in the taste test if they had a high calorie preload.
(note participants were told they were taking part in a taste preference test.)
Extra notes-
The Minnesota Starvation Experiment
Wardle and Beale
Ruderman and Wilson (similar to Hermen and Mack)
Operant Conditioning
Operant conditioning is the distribution of rewards and punishments. Behaviours which produce positive consequences such as compliments and attention are more likely to be repeated.
An example of this would be schemes such as ‘Weight Watchers’ and ‘Slimming World’ where individuals attend meetings and have to follow strict diets. At the meetings the individuals will get weighed and if they’ve lost weight, the rest of the group will distribute the positive comments, encouraging the individual to lose more weight.
This leads on to…
Social Support
This is where people tend to eat less if there are more people around them. If an individual is surrounded with people who are supportive about dieting, then they won’t want to eat as much.
Miller et al (1997)
Conducted a meta-analysis of diet, exercise and diet + exercise weight loss programmes found that the long-term success rate was greater for the diet plus exercise cohort.
Assignment 1- ‘Outline and evaluate factors influencing attitudes to food and eating behaviour, for example cultural influences, mood, health concerns.’ (24 marks)
- Outline 2 factors (choose from culture, mood or health) that influence attitudes to food. Provide examples.
-mood: overeating or under eating when depressed/distressed
-culture: eating what our parents do when we’re younger
2. Explain the psychological theory behind these factors, e.g. Health models (TRB/TPB); Social Learning Theory; conditioning; biological responses; etc.
-overeating or under eating when depressed: this is a biological response.
-eating what our parents do: this tends to happen more when we are younger. Then, as we grow up and start making our own decisions, our attitudes towards food change from that of our parents. This is because of the Social Learning Theory (Bandura). This suggests we learn behaviours through ‘modelling’: observing other people and learning how the behaviour is performed. This is also due to conditioning. Children eat what their parents eat because they see them do it, therefore learn to associate what they eat with being a good thing.
3. Outline supporting studies – at least one in detail.
Social Learning Theory- Bandura, The Bobo Doll experiment
This experiment used children between the ages of 3 and 6 from Stanford University Nursery School. 36 boys and 36 girls took part in the experiment, and one male adult and one female adult were the role models.
Under controlled conditions, Bandura arranged for 24 boys and girls to watch a male or female model behaving aggressively towards a toy called a ‘Bobo doll’. The adults attacked the Bobo doll in a distinctive manner – they used a hammer in some cases, and in others threw the doll in the air and shouted “Pow, Boom”.
Another 24 children were exposed to a non-aggressive model and the final 24 child were used as a control group and not exposed to any model at all.
The researchers pre-tested the children for how aggressive they were by observing the children in the nursery and judged their aggressive behavior on four 5-point rating scales. It was then possible to match the children in each group so that they had similar levels of aggression in their everyday behavior. The experiment is therefore an example of a matched pairs design.
Over eating/under eating
Garg et al (2007) got participants to watch a funny film (Sweet Home Alabama) or a tear jerker (Love Story) whilst the researchers watched the participants choice of snacks; either popcorn or grapes. Those watching Love Story consumed a third more popcorn than the other group whilst those watching Sweet Home Alabama ate more grapes.
Low mood seems also to influence binge eating behaviour. Davis et al (1988) showed that low mood often preceded binge eating in bulimics. The same seems to apply in those with no known eating disorder. Students were asked to record their mood and eating habits over a two week period. Days that included binge eating tended also to be days of low mood, but significantly, binge eating did nothing to improve mood afterwards. So although we may binge when down it seems to do little to make us feel better.
4. Outline challenging studies
Mood- over eating or under eating
Objective:
To investigate whether negative mood and unbalanced nutrition style (fat rich/carbohydrate low) synergistically trigger binge eating in overweight and obese binge eating disorder (BED) patients.
Methods:
After following an unbalanced or a balanced nutrition plan for three days, participants’ food intake in a taste test was measured. During the taste test, participants were either in a negative or a neutral mood that was induced through a guided imagery task.
Participants:
Sixty-nine overweight and obese women with BED (mean age: 36.7 years, mean body mass index: 32.8 kg/m2).
Measurements:
Eating behaviour was assessed by measuring the amount of eaten food during the taste test. Visual analogue scales were used to assess negative effect, tension, urge to eat, and hunger before and after the mood induction and after the taste test.
Results:
Negative mood and unbalanced nutrition had neither a combined synergistic effect nor separate additive effects on the amount of food intake. Negative affect and tension decreased after the taste test in the negative mood group.
Conclusion:
Negative mood does not always enhance the risk of binge-eating behaviour. Fat-rich, carbohydrate-low nutrition style did not influence food intake during a taste test. This finding questions the role of this specific nutrition style as a crucial factor in promoting binge eating. If replicated, these findings are important, since they could guide development of treatment protocols.
A2 Psychology 