Psychology study guide
3.1 Outline principles that define the cognitive levels of analysis and explain how these principles may be demonstrated in research
1. Human beings are information processors and mental processes guide behaviour.- schema theory, darley and gross (1983) 2. The mind can be studied scientifically. -Loftus and Palmer (1974), Corkin et al. (1999) 3. Cognitive processes are influenced by social and cultural factors. -Bartlett (1932), Cole and Scribner (1974), DiMaggio (1997)
What can be learned about localization of function in the brain in relation to memory from the case study of H.M.?
1. The hippocampus and the areas around the hippocampus play a critical role in converting memories of experiences from short-term memory (contemporary store) to long-term memory (permanent store). 2. H.M. could retain memories of what had happened before the surgery. This indicated that the hippocampus is a temporary rather than a permanent memory store. 3. H.M. could learn a few new procedural memories so this indicated that such memories are not stored via the hippocampus. 4. The fact that H.M. (and other people w/ amnesia) had deficits in one part of the memory system but not in others is evidence that the brain has several memory systems and that these are supported by distinct brain regions. 5. The study shows that memory processes are much more complex than originally believed. Although the hippocampus is very important in the storage of new memories it is not the only structure involved in the process.
Evaluation of the case study of H.M.
1. The operation was based on the assumption that H.M.'s seizures would stop and it was successful in this respect, but the brain damage caused memory problems that had not been anticipated. 2. H.M. participated in research for more than 50 years. He participated in many tests (cognitive, observations and neuroimaging studies) 3. This longitudinal case study has contributed enormously to the knowledge of how memory processes are related to specific areas of the brain. The medial temporal lobes are important for the forming, organization, consolidation and retrevial of memories. Cortical areas are important for long-term memory, for facts and events and the use of that info in daily life. Procedural memories are not processed by the hippocampus. 4. There are ethical considerations in this case study. Since H.M. was not able to remember at all times he participated in research it could be argued that it was unethical. However, the findings of the study are very important and justify it. 5. It is not usually possible to use the finding from a single case study to generalize about a larger population, but since the findings from other case studies of people w/ brain damage like H.M. tend to support those from this case study, it may be possible to generalize to some extent.
Schema
A cognitive schema can be defined as a mental representation of knowledge stored in the brain. A schema can be seen as a network of knowledge, beliefs, and expectations about particular aspects of the world. Schema processing is to a large extent automatic, i.e. processed w/ little attention. It involves info from 2 sources: input from the sensory system (bottom-up processes) and information stored in memory (top-down processes), which is used to interpret the incoming info (pattern recognition, interpretation.
Effect 2: Environmental stressors and hippocampal damage in PTSD patients
A stressor in any event that threatens to disrupt the body's normal balance and starts a stress response such as secretion of stress hormones and activation of the 'fear sensor' in the brain, the amygdala. A stressor may be an acute stressor (e.g. being assaulted, having an accident) or it could be a chronic stressor (e.g. anticipated of violence or worrying). The fight at flight response (coping mechanism) is a pattern of physiological responses that prepares the body to deal w/ emergency. Sapolsky (1996) has shown in animal studies that long-term stress and a prolonged flow of cortisol can influence the size of the hippocampus, which plays a major role in memory. Trauma and PTSD: Traumatic episodes (i.e. frightening situations from which a person cannot escape) produce intense fear. In about 5% of the population this may lead to PTSD with effects that can last for a brief period or a lifetime. Combat veterans and survivors of childhood sexual abuse who suffer fromo PTSD tend to have a number of sress related probl,es such as forgetfulness and difficulty learning. In such patients stress-related physiological changes have been observed in the brain, especially in the hipposampus, which play an important role in integrating different aspects of a memory at the time of recollection.
Martinez and Kesner (1991)
ACh in Memory formation. Aim: to investigate the role of ACh in memory formation. Procedure: experimental study using rats. They were trained to run a maze. They were divided into 3 groups. Group 1: recieved injection w/ scopolamine (blocks ACh receptor sites, reducing available ACh). Group 2: recieved injection w/ physostigmine (blocks production of cholinesterase (enzyme) which cleans up ACh from the synapses) leading to more available ACh. Group 3: the control group. Results: Group 1 had problems finding their way through the maze and made more mistakes. Group 2 ran quickly through the maze and made few mistakes. The group was quicker than the control group.
Acetylcholine (ACh)
ACh is a neurotransmitter which has been linked to synaptic plasticity in the hippocampus and it seems to play an important role in learning and short-term memory via the cholinergic system.
Glanzer and Cunitz (1966)
Aim: to investigate recency effect in free recall (i.e. in any order). Procedure: This was a lab experiment where participants first heard a list of items and then immediately had to recall them in that order. Results: Participants recalled words from the beginning of the list (primary effect) and the end of the list (the recency effect) best. If participants were given a filler task just after hearing the last words, the primacy effect disappeared but the recency effect remained.
Bartlett (1932) "The War of Ghosts"
Aim: to investigate whether people's memory for a story is affected by previous knowledge (schemas) and the extent to which memory is reconstructive. Procedure: Bartlett asked British participants to hear a story and reproduce it after a short time and then repeatedly over a period of months or years (Serial reproduction). The story was an unfamiliar Native American legend called "The War of Ghosts". Results: Participants remembers the main idea of the story/gists but they changed unfamiliar elements to make sense of the story by using terms more familiar to their own cultural expectations. The story remained a coherent whole although it was changed. It became noticeably shorter for each reproduction. Bartlett concluded that remembering is an active process. Memories are not copes of experience but rather "reconstructions".
Evidence of the multi-store model of memory: case studies of individuals with amnesia due to brain damage
Amnesia is caused by damage to the hippocampus and related networks involved in storage of new memories. MRI scans show that H.M. had severe damage to the hippocampus which is critical in the storage of info into LTM. H.M. could store new procedural memories (implicit memory) but he was not able to store new explicit memories (semantic or episodic). This shows that the memory system contains different systems.
What is BOA principle 2?
Animal research can provide insight into human behaviour. This means that researchers use animals to study physiological processes because it is assumed that most biological processes in non-human animals are the same as in humans. One important reason for using animal is that there is a lot of research where humans cannot be used for ethical reasons.
Gene mapping
Attempt to determine the effect of a particular gene on behaviour such as psychological traits (temperament), psychological disorders (e.g. depression or schizophrenia) or various physiological conditions.
General issues in brain imaging to consider in a discussion
Brain imaging is mainly about mapping brain structures and activity in the brain. Another limitation deals with localization of function. It may be possible to identify brain structures that are active during a task but, since most structures are linked to other structures in networks, it is not possible at this point to say definitely where things happen in the brain.
Davidson et al. (2004)
Brain waves and compassion meditation. Aim: to investigate whether meditation can change brain activity. 8 monks who had practised meditation for many years and a control group of 10 students who had 1 week of training participated in the study. Cognitive activites (including meditation) produce electrical activity when the neurons fire. This was recorded by the EEG (electroencephalograph which records electrical activity as brain waves). Participants were asked to meditate on 'unconditional compassion', i.e. open the mind for feelings of love and compassion for short periods. The control group participated in a training session where they were asked to think of someone they cared about and to let their mind be invaded by love and compassion. After initial training the participants were asked to generate an objective feeling of compassion without focusing on anyone in particular. The EEG of the monk's brains showed greater activation as well as better organization and coordination of gamma waves. There was a positive correlation b/w hours of practice and level of gamma waves. Evaluation: the results support the idea that attention and affective processes are skills that can be trained but more research is needed to establish if the change in brain waves is caused by hours of training and not individual differences before training.
Brain imaging techniques
Brain-imaging techniques are used in neuroscience to investigate the relationship between behaviour and brain structures, for example after brain damage to find out which areas of the brain are involved in which cognitive activities (cognitive neuroscience). Brain-imaging technology is a promising way to investigate the possible relationship b/w biological factors and behavior, but so far scanning can merely register structures and activity in the brain. It is not possible to determine cause-effect relationships at this point.
Darley and Gross (1983)
Carried out a lab experiment on schema processing in the social world. Participants saw 2 videos of a girl. In video 1 a girl was playing in a poor environment; in video 2 a girls was playing in a rich environment. Then they saw a video of the girl in what could be an intelligence test. When the participants were asked to judge the future of the girls they all said that the "rich" girl would do well and the "poor" girl would do less well. The study demonstrates that participants probably used pre-stored schemas of what it means to be poor and rich and interpret the ambiguous info accordingly. Participants processed info based on a few salient details to form an overall impression that may not necessarily be correct.
2.6 Examine one interaction between cognition and physiology in terms in behaviour. Evaluate two relevant studies.
Cognition- meditation (mindfulness-based stress reduction) may influence brain functions like stress reduction (physiological benefits). Davidson et al. 2004 Brain waves and compassion meditation. Vestergaard-Poulsen et al. (2009) meditation on change in brain structure.
Cognition
Cognitive neuroscience is the scientific study of biological correlates of mental processes (cognition). This area of research investigates how various brain areas are involved in cognitive processes (e.g. how brain damage affects memory), but in recent years researchers have also investigated how cognition and physiological processes may interact in people who meditate. A number of neurotransmitters are examining how meditation or mindfulness-based stress (MBSR) may influence brain functions (e.g. the effect of meditation on attention, emotional reactivity and stress). Interaction of cognition and physiology can be seen in the self-regulation of attention (MBSR) which seems to have physiological benefits (e.g. stress reduction).
COA principle 3
Cognitive processes are influenced by social and cultural factors. Research has shown that cognitive processes such as perception, memory, and thinking are influenced by sociocultural factors.
Explanation of the relationship between H.M.'s brain damage and his memory deficits
Corkin (1997) used MRI scans and analysed the extent of the damage to H.M.'s brain to find out. The scans showed that: Parts of the temporal lobes including the hippocampus and related structures on both sides were missing. This part of the brain's memory system plays a critical role in transforming short-term memories into long-term memories. These areas are involved in specific neurotransmitter pathways in memory (ex acetylcholine is believed to play an important role in learning and episodic memories).
Bouchard evaluation
Correlational data cannot establish cause-effect relationships. Concordance rates were high in the study but far from 100% so it was difficult to determine the relative influence of genes. Calculation of concordance rates is not always reliable. There was no control for the effect of environmental variables in the study and this affects accurate estimations of a genetic contribution to intelligence. The findings from this self-selected sample make it difficult to generalize findings.
2.4 Explain, using examples, the function of two hormones on human behavior
Cortisol and memory- Newcomer et al. (1999). Oxytocin and trust- Baumgartner et al. (2008)
Cortisol and memory
Cortisol is a hormone produced by the adrenal cortex in response to stress and to restore homeostasis. Chronic stress may result in prolonged cortisol secretion and this can lead to physiological changes such as damaged immune system and impairment of learning and memory. This is because high amounts of cortisol results in atrophy of the hippocampus
High levels of cortisol and memory deficits
Cortisol is a stress hormone secreted by the adrenal glands in response to physiological or psychological stress. During long-term stress too much cortisol is released and this may affect not only immune functioning, but also memory processes. Chronic oversecretion of cortisol may hinder the brain in forming new memories or accessing already existing memories.
2.9 Examine one evolutionary explanation of behavior
DIsgust in pregnant women: Fessler et al 2005 Theory of evolution + evaluation of evolutionary explanations
3.4 Explain how biological factors may affect one cognitive process
Damage to the hippocampus and amnesia-H.M. High levels of cortisol and memory deficits- Lupien (1998 and 2002). Sapolsky.
Sapolsky (!968)
Demonstrated that prolonged stress can damage the neurons in the hippocampus but this can be reversed if normal levels of cortisol are restored. Long-term stress could cause irreversible damage.
Dopamine
Dopamine is a NT involved in goal-directed behaviour (motivation) such as pleasure seeking, control of movement, emotional response, and addictive behaviour. Dopamine is released in the brains reward system. Addictive drugs or substances increase the amount of dopamine in the reward system. Dopamine can be released by environmental triggers (ex: the site of cigarette package, food, or a gambling machine) because this is associated with pleasure (reward). Nicotine is the psychoactive ingredient in tobacco, which increases the level of dopamine in the brain's reward circuit causing feelings of pleasure and relaxation.
2.5 Discuss two effects of the environment on physiological processes
Effect 1:Environmental effects on dendritic branching (brain plasticity) Rosenzweig, Bennet and Diamond (1972) Effect 2:Environmental stressors and hippocampal damage in PTSD patients Bremner et al. (2003)
Fessler et al (2005)
Elevated disgust sensitivity in the 1st trimester of pregnancy. Aim: to investigate if disgust sensitivity in the first trimester of pregnancy was elevated as predicted. Procedure: A web-based survey was completed by 691 women recruited through pregnancy-related Web sites. No compensation was offered for participation. The women's mean age was 28.1 years. On the web-based questionnaire, the participants (1) indicated their current level of nausea using a 16-point scale and (2) answered questions to test their disgust sensitivity in 8 different areas (ex food, contact w/ animals, body products, dead animals, hygiene, contact with toilets). Results: Overall, disgust sensitivity related to food and body products in women in the 1st trimester was higher compared to those in the 2nd and 3rd. Disgust was particularly elevated in relation to food as the researchers predicted. Food-borne diseases are particularly dangerous to women in the 1st trimester and therefore it was predicted that disgust sensitivity related to food would be high, this was supported by the results. The results may indicate that nausea and vomiting are evolves behaviour b/c they limit the likelihood that pregnant women will eat dangerous food.
Effect 1: Environmental effects on dendritic branching (brain plasticity)
Environmental stimulation refers to the way the environment provides stimulation in the form of social interaction and learning opportunities for animals and humans. Experiences are processed in the brain's nervous system, and stimulating environments will result in increased numbers of synapses (brain plasticity). Gopnick t al. (1999) describe neurons as growing telephone wires that communicate with each other. An enriched environment is characterized by multiple opportunities to learn new things. Researchers have used animal models to study synaptic changes in the brain because it is not possible to use humans in deprivation experiments. Instead researchers use case studies of children who have grown up in total neglect, i.e. w/ little or no experience of language, touch and interaction w/ other humans. The brains of neglected children are often smaller and there is scientific evidence of altered brain function (e.g. in intelligence and emotions)
2.10 Discuss ethical considerations in research into genetic influences on behavior.
Ethical considerations and concerns Caspi et al 2003
Brewer and Treyens (1981)
Experiment of memory of objects in a room. AIm: to investigate whether people's memory for objects in a room (an office) is influenced by existing schemas about what to expect in an office. Procedure: Participants were 30 university students, who arrived individually to the lab and were asked to wait in an office containing objects (ex desk, typewriter, coffee-pot, calendar). There were also other objects that did not conform to the office schema (A skull, a piece of bark, a pair of pliers). After waiting for some time, participants were taken out of the office and asked to write down everything they could remember from the room. Results: Most participants recalled the schematic objects (desk, typewriter). Some participants reported things that would be expected in a typical office but were not present in this one (ex telephone, books). Many participants also recalled the skull (unexpected object). The very unusual object resulted in better recall than predicted by schema theory.
Newcomer et al. (1999)
Experiment on cortisol and memory. Aim: to investigate how levels of cortisol interfere with verbal declarative memory. Procedure: A self-selected sample (recruied through advertisement) of 51 normal and healthy people aged 18-30 was used. It was randomized, controlled, double-blind experiment running for four days. All participants gave informed consent. 3 experimental conditions. 1: a high level of cortisol (tablet of 160 mg per day), equivalent to cortisol levels in blood as a consequence of a major stressful event. 2: A low level of cortisol (tablet of 40 mg per day), equivalent to cortisol levels in the blood as a consequence of a minor stressful event. 3: A placebo (tablet of no active ingredient). Results: The high-level group performed worse on the verbal declarative memory test than the low-level group. They performed below placebo levels after day 1. The low-level group (mild stress) showed no memory decrease. Evaluation: this was a controlled randomized experiment so it was possible to establish a cause-effect relationship between levels of cortisol and scores on a verbal declarative memory test. Ethical issues were observed w/ informed consent. The negative effect of taking high dosages of cortisol was reversible so no harm was done.
Lupien et al. (2002)
Experiment on cortisol level and memory. Aim: the experiment was a follow-up with 2 groups of the elderly people from the 5 yr study. The aim of the experiment was to see whether it was possible to reverse memory problems w/ a drug. Procedure: participants were divided into 2 groups: group 1 had a moderate level of cortisol at baseline, and group 2 had a high level of cortisol and sign of impaired memory at baseline. Both groups were first given a drug preventing secretion of cortisol (metyrapone). Then they had to do a memory test. After this, both groups were given another drug (hydrocortisone) to restore their levels of cortisol to previous levels. Results were compared w/ levels in a placebo group. Results: showed that participants w/ a moderate level of cortisol who were given metyrapone had no problem restoring normal memory function. Participants who, from the start, had high level of cortisol had no memory improvement. Hydrocortisone caused even greater memory loss.
Differences (multi-store model)
Focus on the entire memory system. Simplistic model of STM- not much focus on interaction b/w stores. STM temporary storage and gateway to LTM. No specifications of content of STM.
DIfferences (working memory model)
Focus primarily on STM. Much more complex idea of STM suggesting possible interactions b/w the stores, and especially modality-based functions of short-term memory (visuo-spatial sketchpad and phonological loop). The addition of a governing system (central executive) is a strength, although how it works is not yet well documented.
Lupien et al. (1998)
Followed a group of elderly people for 5 yrs to study the role of cortisol on memory. They found that cortisol secretion was too high in about 30% of the elderly population. Those who were exposed to excessive cortisol secretion for 5 yrs showed memory impairment and atrophy (Shrinking) of the hippocampus. They also found that memory impairment can be reversed if the damage had not progressed to "a point of no return".
2.8 With reference to relevant research studies, discuss the extent to which genetic inheritance influences human behavior.
Gene mapping- Caspi Twin studies-Bouchard Problems in genetic research
Ethical considerations in research
Genetic research can only reveal a potential risk. Anonymity and confidentiality: Participants in a genetic study must be sure that their anonymity and confidentiality is protected but in family and twin studies it can be difficult to ensure this fully. This is also the case in the research or rare disorders. Participants have a right to know who owns the genetic info and how it will be used in the future (Ex if their access to insurance or employment could be compromised because of the genetic data. Informed consent and the right to refuse or withdraw: Participants have a right to be fully informed about what the research is about, the procedures,what could be the result of the study and how the info will be used. Research into genetic influences on behaviour could potentially pose risks to participants and the genetic info could be misused. Genetic research can reveal information that is unexpected or a source of distress to participants (ex when a participant has no sign of disorder but the data shows a genetic predisposition).
Problems in genetic research
Genetic research cannot at this point determine the extent to which genetic inheritance influences behaviour because: Genes interact w/ environmental factors in complex ways. It is difficult to measure relative influence of genes and environmental factors. Knowledge about genes is still limited. There are problems in genetic research (ex concordance rates in twin studies cannot say anything about cause-effect relationships). MZ twins being treated in the same way as DZ twins may be wrong (the "equal environment assumption" may be flawed) and this limits the possibility of drawing meaningful conclusions from twin studies.
H.M.'s memory
H.M. could no longer store new memories (anterograde amnesia). Most of his memories from before the operation remained intact (partial retrograde amnesia). He could not transfer new semantic and episodic memories (explicit memories) into LTM. He could form new long-term procedural memories (implicit memories). He was able to carry on normal conversations (i.e. had some capacity for working memory) but he would forget what the conversation was about immediately.
H.M.'s story
H.M. suffered from epileptic seizures after he fell off a bike, aged 7. It was assumed that the seizures were connected to the accident and he became increasingly incapacitated. When H.M. was 27, the neurosurgeon William Scoville, performed experimental surgery in order to stop the seizures. Tissue from the medial temporal lobe, including the hippocampus, was removed on both sides of his brain. After the operation H.M. suffered from amnesia. He could not create new episodic and semantic memories, but he was able to learn a few procedural memories. His personality remained unchanged and there was no general intellectual impairment. This case study shows that the hippocampus is important in memory processing and particularly in the storage of new memories. H.M. participated in research studies until his death in 2008, and his brain was donated to science.
2.2 Explain one study related to localization of function in the brain
HM
What is BOA principle 3?
Human behavior is, to some extent, genetically based. This means that behavior can to some extent be explained by genetic inheritance, although this is rarely the full explanation since genetic inheritance should be seen as genetic predisposition which can be affected by environmental; factors. Researchers often use identical twins which are genetically identical and act as a control for each other. Twins never show 100% concordance so genes dispose not cause behavior. Environment also influences.
COA principle 1
Human beings are information processors and mental processes guide behaviour.
Evaluation of evolutionary explanations
It is difficult to test evolutionary theories and not much is known about the life of early humans. Evolutionary explanations tend to focus on biological factors and underestimate cultural differences. According to Dacey (1974) disgust for spiders may be explained by people's need to find tangible causes of illness and disease when the causes are unclear.
Concerns continued-
Knowledge about the role of specific genes in behaviour is still limited so researchers should be careful about making definite conclusions. Genetic research is correlational by nature so one should be careful to make definite conclusions about the risk of developing a disease. Genetic research into complex behaviour such as homosexuality is controversial b/c of the social meaning and significance of homosexuality. Genetic research could result in stigmatization and discrimination as many societies are homophobic. The search for the "gay gene" has generally raised controversy.
Caspi et al. (2003)
Longitudinal study on the possible role of the 5-HTT gene in depression after experiences of stressful events. The 5-HTT gene influences the level of serotonin, which is known to play a role in controlling mood. The researchers compared participants with a normal 5-HTT gene and a mutation of the 5-HTT gene w/ shorter alleles. Both types are quite frequent in humans but the long allele is slightly more frequent. (57%). The researchers found that participants who carried a mutation of the 5-HTT gene and who had experienced many stressful events were more likely to become depressed after stressful events than those participants who carried the normal 5-HTT gene. The 5-HTT gene could indicate a vulnerability to depression after stress and the researchers speculated whether the gene could moderate individual responses to environmental factors.
Caspi et al 2003
Longitudinal study on the possible role of the 5-HTT gene in depression after experiences of stressful events. The researchers compared participants w/ a normal 5-HTT and a mutation of the 5-HTT gene w/ shorter alleles. Both types are quite frequent in the human population but the long allele is slightly more frequent (57%). The researchers found that participants who carried a mutation of the 5-HTT gene and who had experienced many stressful events were more likely to become depressed after stressful events than those participants who carried the normal 5-HTT gene. Conclusion: It is not clear what to do w/ knowledge from genetic research and genetic screening at this point- both at an individual level and in society. For example, being genetically predisposed to depression does not mean that a person will develop depression. The results of genetic screening for depression could cause personal distress and have a negative impact on someone's life (ex if based on this they decided not to have children)
MRI scan: magnetic resonance imaging
MRI scans can give detailed pictures of internal structures in the body. The body consists, to a large extent, of water molecules. In the MRI scanner a radio frequency transmitter is turned on and it produces an electromagnetic field. Strengths: MRI scan are particularly useful to show how the blood flows in the brain and can be used to identify problems w/ blood circulation. They can be used for the early detection of Alzheimer's disease. They are safe to use since no radioactive material is used. Limitations of MRI: they are very expensive. Movement may affect the pictures. They cannot say anything about cause-effect relationship.
3.3 Evaluate two models or theories of one cognitive process with reference to research studies
Model 1: the multi-store model of memory (Atkinson and Shiffrin, 1968). Glanzer and Cunitz (1966) Evidence of the multi-store model of memory: case studies of individuals with amnesia due to brain damage. Model 2:The working memory model (Baddeley and Hitch, 1974) Quinn and McConnel (1996).
Twin Studies
Monozygotic twins (MZ/identical) come from same egg, share 100% of their genes. Dizygotic twins (DZ/fraternal) come from 2 different eggs, share around 50% of their genes. Siblings share 50% of their genes. The researchers calculate concordance rate (the likelihood or probability that if one individual has the trait the other will also have it). Concordance rate is assumed to establish if or what extent a certain trait is inherited. In twin studies , one twin acts as control for the other twin. The classic twin study only studied concordance rates and did not include environmental factors. In some cases MZ twins were raised apart and in these cases it was assumed that differences were due to environmental factors. In twin research, ses of MZ are compared w/ sets of DZ twins for a particular trait or disorder. High concordance rates in MZ twins and lower concordance rates in DZ twins for the same behavior indicate that the trait or disease is linked to genes (inherited). Differences w/in pairs of identical twins are attributed to environmental factors.
One evolutionary explanation of behavior: disgust in pregnant women.
Nausea and loss of appetite during pregnancy may have been evolved as a way to protect the mother and the fetus against diseases which could threaten the fetus. Disgust has evolved as a food-rejection response to prevent contamination and the spread of illness. The theory under investigation is whether disgust has evolved to compensate for the mother and the baby's vulnerability to disease during the first few months of pregnancy.
2.3 Explain, using one or more examples, the effects of neurotransmission on human behavior.
Neurotransmission. Dopamine (pleasure): Berridge and Kringelbach (2009) and Fisher (2004). ACh (learning/short term memory): Martinez and Kesner (1991)
2.1 Outline principles that define the BOA and explain how these principles may be demonstrated in research.
P 1: there are biological correlates of behavior. Newcomer(cortisol on verbal declarative memory) P 2: animal research can provide insight into human behavior. Rosenzweig & Bennett (environment on rats brain plasticity) P 3: human behavior is to some extent genetically based. Bouchard (Minnesota twins role of genes in IQ)
Possible ways in which schemas affect memory
People tend to remember the meaning (gist) of something, not the actual wording. People use stored knowledge to makes sense of incoming information. If the information is unclear or incomplete, they fill in the blanks or interpret using their schemas. This is called "reconstructive memory" and results in distortion. People tend to ignore info that is not in line w/ their schemas (aschematic info). This may lead to bias in info processing (Ex stereotyping where people ignore info that is not in line w/ their schema). People tend to focus on info that is in line w/ their schema (schematic info). This may result in "confirmation bias".
Newcomer et al. (1999)
Performed an experiment on the role of the stress hormone cortisol on verbal declarative memory. Group 1 (high dose cortisol) had tablets containing 160 mg of cortisol for four days. Group 2 (low dose) 40mg/day. Group 3 (control) placebo tablets. Participants listened to a prose paragraph and had to recall it as a test of verbal declarative memory. This memory system is often neg affected bu the increase level of cortisol under long-term stress. The results showed that group 1 showed worse performance on memory test than 2 and 3. The experiment shows than an increase in cortisol over a period of time has a negative effect on memory.
Rosenzweig and Bennet (1972)
Performed an experiment to study the role of environmental factors on brain plasticity using rats as participants. Group 1 was placed in an enriched environment w/ lots of toys. Group 2 was placed in a deprived environment w/ no toys. The rats spent 30 or 60 days in their respective environments before being killed. The brains of the rats in group 1 showed a thicker layer of neurons in the cortex compared to the deprived group. The study shows that the brain grows more neurons if stimulated.
Loftus and Palmer (1974)
Performed an experiment to test reconstructive memory in relation to eyewitness testimony. The aim was to see whether misleading questions could distort memory. Participants saw a picture of a car based on questions such as "How fast was the car going when it smashed/hit/bumped into the other car?" Words such as "smashed" elicited higher speed estimations. Because the experimental method was used it was possible to establish a cause-effect relationship b/w the use of specific words and estimation of speed. Experimental research on memory has been criticized for lacking ecological validity.
Similarities of the multi-store model and the working memory model
Provide possible architecture of the memory system (several stores). STM temporary storage, limited capacity and duration.
Evaluation of working memory model
Provides a better explanation of storage and processing than the multi-store model in that it can be applied to understanding, reading and mental calculations. Early versions of the model are vague on the role of the central executive, but later development of the model suggests that central executive guides attention via two systems (automatic and supervisory attentional system). The model is broadly accepted and considered important for understanding not only memory processes, but also cognitive processes such as thinking and problem solving (functional approach).
Evaluation of the multi-store model
STM and LTM are more complex than the model assumes. There is not enough focus on the interaction b/w the stores (ex how info from LTM is used to deal w/ chunking in STM). Rehearsal is not enough to explain transfer of info to LTM. The model cannot explain why memory strategies and elaborate rehearsal is efficient.
3.2 Evaluate schema theory
Schema+ways schema affect memory, stengths and limitations of schema theory Bartlett (1932), Darley and Gross (1983) DiMaggio (1997), Brewer and Treyens (1981)
Scoville and Milner (!957) The case study of H.M.
Scoville and Milner (1957) described the case of H.M. who fell off his bicycle when he was 7 years old, injuring his head. He began to have epileptic seizures when he was 10. By the age of 27 the epileptic attacks prevented him from living a normal life. Scoville performed an experimental surgery on H.M.'s brain to stop seizures. The seizures stopped but H.M. suffered from amnesia for the rest of his life. The case study of H.M. provides info on how particular brain areas and networks are involved in memory processing. This helped scientists to formulate new theories about memory functioning.
Caspi et al (2003) evaluation
Since a large proportion of the population carries the mutation of the 5-HTT gene that makes them susceptible to depression after traumatic events, it can be difficult to conclude that the gene is a major contribution to depression. People who did not carry the mutation also became depressed. The study showed a correlation b/w the presence of a 5-HTT short allele and depression but it is not possible to establish a cause-effect relationship. Genes contribute to some extent to behavioural traits and disorders but it is not clear how environmental factors influence genes, Environmental factors were included in the study (stressful events) but there is no evidence against the idea that it could be the stressful events (environmental factors) that made people depressed. Much more research is needed before a clear relationship b/w a gene and a behavioral trait can be established.
Strengths and weaknesses of schema theory
Strengths: Schema theory has proven extremely useful in explaining many cognitive processes (ex perceptions, memory, and reasoning). Schema theory can be used to explain the reconstructive nature of memory, for example in eyewitness testimony, stereotyping, gender identity (gender schema) and cultural differences (cultural schemas). Limitations: Cohen (1993) argued that: the concept of schema is too vague to be useful and it is not clear how schemas are acquired in the first place. Schema theory may focus too much on the inaccuracies of memory but most of the time people remember accurately.
Bremner et al. (2003)
Stress, PTSD and memory problems related to reduction of hippocampal volume Aim: To measure the volume of the hippocampus based on the theory that prolonged stress may reduce the volume of the hippocampus due to increased cortisol levels. Procedure: MRI scans were made of the participants and participants completed memory tests (e.g. remembering a story or a list of words). The participants were veterans and female adults who had experienced early childhood sexual abuse. Some had developed PTSD, but not all. Results: the researchers found that there were deficits in short-term memory and then performed MRI scans of the participants brains. They found that the hippocampus was smaller in PTSD patients than in a control group. The veterans with most memory problems also had the smallest hippocampus. The findings showed a clear correlation b/w number of years of abuse as measured by a trauma test, memory problems and hippocampal volume. People suffering from PTSD often suffer from other psychological disorders (e.g. depression) which could perhaps also play a role in the observed changes in the brain. Evaluation: The sample was very small so it is difficult to say anything definite about the relationship b/w trauma and hippocampal volume. There could be alternative explanations to differences in hippocampal volume (e.g. that people who suffer from PTSD often suffer from depression as well). Depression is also associated w/ reduction of the hippocampus. However, the findings of large reduction of hippocampal volume in combat-related PTSD has been replicated many times.
4 parts of working memory
The central executive: A controlling system that monitors and coordinates the operations of the other components (slave systems). The central executive is modality free so it can process info in any sensory modality but it has limited capacity. The episodic buffer: A limited capacity temporary storage system or interface b/w the other systems in working memory. It is assumed to be controlled by the central executive through conscious awareness. The episodic buffer handles info in various modalities and resembles the concept of episodic memory. The phonological loop: handles verbal and auditory info. It is divided into 2 components: the articulatory control system: the "inner voice", the phonological store: the "inner ear". The visuospatial sketchpad: the "inner eye". THis handles visual and spatial info from either sensory memory (visual info) or from LTM (images).
Fessler evaluation
The data was collected through questionnaires. Self-reports may not be reliable. This is not an effective way of measuring disgust. It would have been more reliable to confront participants w/ real disgust-eliciting objects. The effect sizes were not big but significant. The findings are supported by other studies (ex Curtiss et al 2004) showing that images that threaten the immune system are judged as more disgusting.
Evaluation: Rosenzweig, Bennet and Diamond (1972)
The experiment was a rigorously controlled lab experiment so it was possible to establish a cause-effect relationship. The experiment used animal models and therefore it may be difficult to generalize to humans unless research w/ humans provides the same results. Follow-up of this research indicated that just 2 hours a day in an enriched environment produced the same plastic changes in the brain as in rats that had been constantly in the EC condition. This shows that the brain can change and adapt to new situation. Since brain plasticity is assumed to follow the same pattern in animals and humans the implications of the study are that the human brain will also be affected by environmental factors such as intellectual and social stimulation. The research challenged the belief that the brain weight cannot change. This was an important finding. There are ethical issues in the use of animals in research like this. Since the results contributed to a much better understanding of the role of environmental factors in brain plasticity it can be argued that the research was justified in spite of ethical issues.
fMRI scan: functional magnetic resonance imaging
The fMRI scanner measures changes in blood flow in the active brain. This is associated w/ use of oxygen and linked to neural activity during information processing. When participants are asked to perform a task, the scientists can observe the part of the brains that corresponds to that function. fMRI scanning is widely used by cognitive neuroscientists and other researchers and its use has increased enormously over the last 10 years. Strengths: it does not use radioactive substances. U can record activity in all regions of the brain. Limitations: the focus is mostly on localized functioning in the brain and does not take into account the distributed nature of processing in neural networks. The results are correlational so it is not possible to establish cause-effect relationships.
Oxytocin and trust
The hormone oxytocin is secreated by the hypothalamus and released (1) into the blood stream via the pituitary gland or (2) into the brain and spinal cord where it binds to oxytocin receptors. Oxytocin acts primarily as a neurotansmitter in the brain. Has been linked to trusting other people. Experimental manipulation of oxytocin levels has shown increase in trust. According to evolutionary psycholigists, trust is an important social tool in the relationship between humans. Trust is an adaptive mechanism as it helps humans to form meaningful relationships at a personal and proffesional level. Betrayal disrupts bonds of trust and may result in avoidance of the person who has betrayed you. Learning who to trust and who to avoid is important for survival and the well-being of an individual. Humans should also be able to move on after experiences of breaching trust if long-term relationships and mental well-being are to be preserved. Oxytocin could play a role in reducing fear reactions via the amygdala that may arise as a consequence of betrayal.
Limitations of working memory
The major criticism of the first models of working memory was unclear role of the central executive. This has been dealt with by including the episodic buffer in the revised model. The model has been criticised for its emphasis on structure rather than processing
What can be learned about the relationship b/w the brain and memory from the case study of H.M.?
The memory systems in the brain constitute a highly specialized and complex system. The hippocampus plays a critical role in converting memories of experiences from STM to LTM (the permanent store). H.M. was able to retain some memories for events that happened long before his surgery. This indicates that the medial temporal region w/ the hippocampus is not the site of permanent storage in itself. It rather seems to play a role in how memories are organized and then stored elsewhere in the brain. The medial temporal region with the hippocampus is important for forming, organizing, consolidating, and retrieving memory. Cortical areas are important for long-term storage of knowledge and how to use this knowledge in everyday situations. The fact that H.M. and other people w/ amnesia have deficits in some types of memories but not in others is taken as evidence that the brain has multiple memory systems that are supported by distinct brain regions.
COA principle 2
The mind can be studied scientifically. Cognitive researchers use a number of scientific methods to study the mind (ex lab experiments, neuroimaging, case studies, interviews, and archival research). The most used research method was, for a long time, the lab experiment because it was considered the most scientific.
Strengths of working memory
The model has been useful in understanding which parts of the memory system may be linked to underlying problems in reading and mathematical skills. The model focuses on the processes of integrating info, rather than on the isolation of the subsystems. This provides a much better basis for understanding the more complex aspects of executive control in working memory.
Limitations of the multi-store model of memory
The model is very simplistic and it cannot account for how interaction b/w the different stores takes place (ex how info from the LTM may indicate what is important and relevant to pay attention to in sensory memory). Research into the encoding of LTM has challenged the single-store version of LTM. It is now accepted that the LTM contains several stores (ex semantic, episodic, procedural).
Strengths of the multi-store model of memory
The model pioneered the new approach to memory where humans are seen as information processors. The model's conceptualization of memory as multi-stored is supported by research. It has been possible to make predictions based on the model and to design experiments. The overall model has been modified, for example by Baddeley and Hitch (1974) w/ their new version of short-term memory, the "working memory" model.
Model 1: The multi-store model of memory (Atkinson and Shiffrin, 1968)
The multi-store model is based on the assumption that memory consists of a number of separate stores and that memory processes are sequential. The memory stores in the model are structural components that include control processes (Ex attention, coding, and rehearsal). Rehearsal ensures the transfer of info from short-term memory (working memory) to long-term memory. Sensory memory registers sensory info and stores it for around 1-4 sec. Info in the sensory memory is modality specific (related to different senses). Only a small amount of the sensory information will be transferred into the short-term memory store (depending on whether or not it was attended to). STM has limited capacity (around seven items) and limited duration (Around 6-12 seconds). Info processed in STM is transferred into LTM if it is rehearsed. If not, it is lost. LTM is believed to be of indefinite duration and of potentially unlimited capacity.
Bartlett Evaluation
The results of the study confirm schema theory (and reconstructive memory), but it was performed in a lab and can be criticized for lack of ecological validity. Participants did not receive standardized instructions and some of the memory distortions may be due to participants guessing (demand characteristics). In spite of these methodological limitations, the study is one of the most important in the study of memory.
Rosenzweig, Bennet and Diamond (1972)
The role of environmental stimulation on brain plasticity. Aim: to investigate whether environmental factors such as rich or an impoverished environment affect development of neurons in the cerebral cortex. Procedure: rats were placed in either an enriched environment (EC) or in an impoverished condition (IC). EC: 10-12 rats in a cage provided w/ different stimulus objects to explore and play w/. This group also received maze training. IC: each rat in an individual cage (isolation and no stimulation). The rats typically spend 30 to 60 days in their respective environments before they were killed so the researchers could study changes in brain anatomy. Results: The anatomy of brain was different for rats in the EC and the IC. The brains of EC rats had increased thickness and higher weight of the cortex. EC rats had developed more acetylcholine receptors in the cerebral cortex (important neurotransmitter in learning and memory).
Baumgartner et al. (2008)
The role of oxytocin in trust in economic behaviour. Aim: to investigate the role of oxytocin after breaches of trust in a trust game. Procedure: The participants played a trust game used by economists and neuroscientists to study social interaction. The "investor" (player 1) receives a sum of money and must decide whether to keep it or share it with a "trustee" (player 2). If the sum is shared the sum is tripled. Then player 2 must decide if this sum should be shared (trust) or kept (violation of trust). fMRI scans were carried out on 49 participants. They received either oxyocin or placebo via a nasal spray. Participants played against different trustees in the trust game and against a computer in a risk game. In 50% of the games their trust was broken. They received feedback on this from the experimenters during the games. Results: participants in the placebo group were likely to show less trust after feedback on betrayal. They invested less. Participants in the oxytocin group continued to invest at similar rates after receiving feedback on a breach of trust. The fMRI scans showed decreases in responses in the amygdala and the caudate nucleus. The amygdala is involved in emotional processing and has many oxytocin receptors. The caudate nucleus is associated w/ learning and memory and plays a role in reward-related responses and learning to trust. Evaluation: Oxytocin could explain why people are able to restore trust and forgive in long-term relationships. Scanner research is merely mapping brain activity but nothing definite can be said about what it really means at this point in science. Giving oxytocin like this is an experiment may not reflect natural physiological processes. The function of oxytocin is very complex and it is too simplistic to say that it is "the trust hormone".
Evidence of the multi-store model of memory: the serial position effect.
The serial position effect is believed to be linked to rehearsal, i.e. people repeat things in order to remember. The serial position effect suggests that people remember things better if they are either the first (primary effect) or last (recent effect) item in a list of things to remember. The recency effect could be due to words still being active in STM (working memory). Rehearsal could be a factor in transfer of info into LTM.
Brewer and Treyens Evaluation
The study confirms schema theory (and reconstructive memory), but it was a controlled lab experiment so there are issues of artificiality. The study used deception (participants were not told about the real purpose of the experiment) but they were debriefed afterwards and not harmed. The study could not have been made w/out deception so it was justified. There is sample bias. University students were used as participants so it may be difficult to generalize the results.
Martinez and Kesner (1991) evaluation
The study shows that ACh is important in memory since the rats showed different memory capacity depending on ACh level. Since it was a controlled lab experiment it can be concluded that the level of ACh is one factor that affects memory but the neurobiology of memory is very complex.
The theory of evolution
The theory of evolution, suggested by Charles Darwin, is based on the assumption that living organisms face environmental challenges. Organisms that adapt the best have a greater chance of passing on their genes to the next generations. Organisms w/ specific genetic traits that enhance survival are said to be naturally selected. Natural selection is a crucial evolutionary process in Darwin's theory.
What is BOA principle 1?
There are biological correlates of behavior. THis means that there are physiological origins of behavior such as NTs, hormones, specialized brain areas, and genes. BOA level of analysis is based on reductionism, attempt to explain complex behavior in terms of simple causes.
Ethical considerations in genetic research
There are specific issues of concern in genetic research within the biological level of analysis. This is particularly true in the search for genes involved in abnormal behaviour, but it is also relevant in research on genetic influence on disease, intelligence, personality or health. The main reasons for concerns are:
Evidence of the working model of memory
There is evidence of working memory in the so-called dual tasks experiments. The model assumes that there is a division of tasks b/w the different slave systems according to modality. If 2 tasks are done simultaneously (ex in dual tasks experiments or in multi-tasking) it is possible to perform well if separate systems are used. If concurrents tasks use the same system, it will affect performance negatively.
The case study of H.M.
This case study is important because it provided evidence that there are different memory systems in the brain. Milner (1957) was the first to report the case of H.M. and the profound effects on memory functioning, following an operation which removed the hippocampus and adjacent areas in H.M.'s brain. Corkin et al. (1997) did a MRI scan of H.M.'s brain. Brain imaging was used because it allowed the researchers to get a precise picture of the brain damage. They discovered that parts of the temporal lobe, including the hippocampus and the amygdala, were missing, but also that the damage was not as extensive as previously believed.
Fisher (2004) on dopamine in "addiction to love"
This is an evolutionary explanation of behavior. "Being in love" has similarities with "being addicted" according to Fisher. Dopamine increases desire and reward by triggering the same emotional rush of pleasure when you see of think of the loved one as if you were taking a drug like cocaine. Dopamine can explain the highs of romantic passion (high levels of dopamine) and the lows of rejection (low levels of dopamine).
Model 2: The working memory model (Baddeley and Hitch, 1974)
This model challenged the view that STM is unitary and that info processing is passive. Working memory is seen as an active store used to hold and manipulate info. Working memory includes 4 separate components; the central executive, the episodic buffer, the phonological loop, the visuospatial sketchpad.
Glanzer and Cunitz Evaluation
This study supports the idea of multiple stores (STM and LTM). This is a controlled lab study w/ highly controlled variables, but there is no random allocation of participants to experimental conditions so it is not a true experiment. There may be problems with ecological validity.
Bouchard et al. (1990)
Twin study investigating genetic inheritance in intelligence. This study used a self selected sample of MZ twins who had been reared together (MZT) and MZ twins who had been reared apart (MZA) to investigate concordance rates for variables such as IQ. The results showed that for IQ (measured by a standardized intelligence test called WAIS) the concordance rate was 69% for MZA and 88% for MZT. The researcher concluded that environmental factors do play a role in development of intelligence but IQ is to a large extent inherited and that 70% of the observed variation in the sample could be attributed to genetic variation. They claim that results indicate in a sample like this one (white, middle-class in an industrialized nation) genetic inheritance in IQ accounts for around 2/3 of the observed variance of IQ. They also said that their findings do not indicate that IQ cannot be increased, that is influenced by environmental factor.
Synaptic tansmission
When a nerve impulse reaches the end of the neuron, the neuron fires and neurotransmitters are release into the synaptic gap where they travel to the neuron at the other side of the synaptic gap. If the NT is not absorbed it can be re-uptaken, diffused out or destroyed. The NT then binds to specific receptors at the other side. If a NT is blocked or replaced (ex b/c another chemical interferes) then the messages change. This affects the physiological system, cognition, mood or behavior.
Baddeley and Hitch (1974)
asked participants to answer increasingly difficult questions about simple letter combinations that were shown at the same time. Reaction time increased as the questions became more difficult. The participants were then asked to do an articulatory suppression task (ex repeating "the" all the time, repeating numbers from 1 to 6, or repeating random numbers) while they answered the question. There was no significant difference in reaction time b/w the group who was asked to repeat "the" or to repeat numbers from 1 to 6. The group who was asked to repeat random numbers has the worst performance. This was interpreted as overload problems for the central executive.
Quinn and McConnel (1996)
asked participants to learn a list of words by using either imagery or rehearsal. The task was performed on its own or in the presence of a concurrent visual noise (changing patterns of dots) or a concurrent verbal noise (changing patterns of dots) or a concurrent verbal noise (speech in a foreign language). The results showed that learning words by imagery was not affected by a concurrent verbal task but it was disturbed by a concurrent by a concurrent visual task. The opposite was found in the rehearsal condition. This indicates that imagery processing uses the visuospatial sketchpad whereas verbal processing uses the phonological loop. If 2 tasks used the same component, performance deteriorated. The study thus lends support to different modality-specific slave systems and the idea of limited processing capacity.
Schema theory
defines cognitive schemas as mental representations of knowledge. Mental representations (schemas) are stored in categories (concepts) in memory. These schemas provide guidelines for interpretation of incoming information when people try to make sense of the world. Schemas influence cognition in that schemas create expectations about what will happen in specific situations (Ex what a "teacher" is like or what to expect when you go to a rock concert). Schema theory can, to a large extent, explain reconstructive memory and stereotyping.
Berridge and Kringelbach (2009) on dopamine in pleasure seeking
fMRI scans were used to study brain areas involved in the subjective experience of pleasure. They found that the orbitofrontal cortex was active when people reported feeling pleasure. The researchers concluded that: dopamine and the nucleus accumbens in perhaps rather involved in pleasure seeking. This could explain addictive behavior (ex: nicotine leads to craving) The orbitofrontal cortex and natural opiods (endorphins) are perhaps linked to the subjective experience of pleasure.
Vestergaard-Poulsen et al. (2009)
found that extensive practice of meditation involving sustained attention could lead to changes in brain structure. They found structural changes in the lower brain stem of participants engaged in long-term practice of meditation compared w/ age-matched non-meditators. MRI scans of 2 groups of participants- mediators and non-meditators. The study found structural changes in brain stem regions concerned w/ control of respiration and cardiac rhyth, (autonomic nervous system). The connection of neurons in this area seemed more complex in people who meditated. This could explain some of the beneficial effects found in research on stress reduction techniques such as MBSR because cortisol levels are reduced and the cardiac and breathing rhythm slow down. Meditative practices have already been applied in health psychology, for example Davidson et al. (2003) found that Mindfulness meditation could increase positive emotion and immune responses. MBSR has also been found to alleviate pain (Grant et. al 2010).
Bartlett (1932)
introduced the concept of "cultural schema" in memory research. He suggested that schemas influence memory in that they lead to distortion or "reconstructive memory". Other researchers suggest that the environment in which people live leads to distortion or "reconstructive memory". Other researchers suggest that the environment in which people live leads to specific cultural and social demands that influence the way they process information. Suggested that memory is guided by schema and that culture can influence schemas. Precious knowledge determines the way people interpret incoming information and memory (memory distortion). He asked British participants to read an unfamiliar Native American story and reproduce it. The participants changed details of the story to fit w/ their own cultural schemas.
Cole and Scribner (1974)
investigated how memory strategies were influenced by culture. The study asked children from a rural area in Liberia and children from the USA to memorize items from 4 different categories: utensils, clothes, tools, and vegetables. Children from the US improved performance after practice but the Liberian children did not unless they had attended school. Learning memory strategies, like "chunking", appears to be dependent on schooling and the illiterate children in the study did not use these strategies. The researchers concluded that the way cognitive psychologists study memory processes does not always reflect the way people learn to remember in real life.
Darley and Gross (!983)
performed an experiment in which they showed participants videos of a girl playing in a poor environment, then in a wealthy environment. Then they saw a video of the girl in what could be an intelligence test. When the participants were asked to judge the future of the girl they all said that the "poor" girl would do worse than the "wealthy" girl. The study demonstrated how human beings actively process info based on a few salient details to form an overall impression that may not necessarily be correct.
Bouchard et al. (1990)
performed the Minnesota twin study, a longitudinal study investigating the relative role of genes in IQ. The participants were MZ reared apart (MZA) and MZ reared together (MZT). The researchers found that MZT had a concordance rate of IQ of 86% compared to MZA had a concordance rate of IQ at 76%. This shows a link between genetic inheritance and intelligence but it does not rule out the role of the environment.
DiMaggio (1997)
suggests that schemas are (1) representations of knowledge (ex stereotypes and social roles) and (2) mechanisms that simplify cognition in the form of "cognitive shortcuts" that are shaped by culture. Schematic cognition is shaped and biased by culture (ex culturally based stereotypes).
DiMaggio (1997)
suggests that schemas are (1) representations of knowledge (ex stereotypes and social roles) and (2) mechanisms that simplify cognition in the from of "cognitive shortcuts". Schematic cognition is shaped and biased by culture (ex in culturally based stereotypes). Gender schemas shaped by socio-cultural ideas about what is appropriate for men and women (i.e. norms).
Bartlett (1932)
suggests that schemas are active recognition devices representing an effort after meaning. Schemas help people make sense of the world, make predictions about it and what to expect, and provide guidance on how to behave.
Corkin et al. (1999)
used MRI scans to observe the exact damage to H.M.'s brain. H.M. suffered from amnesia due to a brain operation where the hippocampus and adjacent areas had been removed to eliminate his epilepsy. The scans confirmed damage to these areas. Although a small part of the hippocampus had been spared it was not enough to support storage of new explicit memories.
Ashtari et al (2009)
used MRI to investigate whether substance abuse (marijuana) can damage the developing brain in adolescents and young adults. The researchers scanned the brains of 14 young men w/ a history of heavy marijuana abuse over a long period. The control group consisted of 14 young men who had not used marijuana. The results of the scan indicated that there were brain abnormalities in the frontal, parietal, and temporal regions of the brains of the marijuana users. The development of white matter (myelin) was affected and this could explain slow information processing in the brain. The researchers concluded that early marijuana use can affect brain development negatively but since the study gave correlational data more research is needed.
Harris and Fiske (2006)
used fMRI scans to study students brain processes as a response to being presented w/ pictures of extreme outgroups. This study in social cognition aimed to find the biological correlates of stereotypes and prejudice. The researchers scanned students while they were watching either pictures of different humans or objects. It was predicted that the medial prefrontal cortex would be active when participants looked at humans but not when they looked at objects. This was found except when participants looked at pictures of people from extreme outgroups such as the homeless and addicts. Brain regions related 'disgust' were activated and there was no activity in the prefrontal cortex. The researchers concluded that this indicated a dehumanization of the outgroups. These groups were apparently viewed as 'disgusting objects' and not people.
