1 Our Brains are made in a way that allows it to adapt to the environment that it is placed in. Neurotransmission and hormones adapt to the specific environment it is placed in. This is has been shown in research dealing with adaptation to violent environments and neurotransmission desensitization. Research should be used to support your explanation. 2 Early 20th century: believed that brain was only influenced by genes and thus unchangeable Now we know that environmental enrichment /deprivation(an environmental factor) can modify the brain (a physiological process). 3 The effect of Deprivation and Stimulation on Neuroplasticity 4 Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment Plasticity occurs on a variety of levels, ranging from cellular changes involved in learning, to large-scale changes involved in cortical remapping in response to injury and disease. 5 Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment Plasticity occurs on a variety of levels, ranging from cellular changes involved in learning, to large-scale changes involved in cortical remapping in response to injury and disease. 6 Neurons can compensate for injury or disease or to adjust their activities in response to new situations or changes in the environment. The brain is most plastic early in life (This is known as the critical period). The brain can rearrange the connections between neurons (dendritic branching) 7 The brain can generate new neurons throughout life (neurogenesis) Learning can increase/decrease neurotransmission between specific neurons (long term potentiation) It is assumed that as your behavior changes (in most cases because of environmental change), so does the underlying neural circuitry. 8 Environmental enrichment concerns how the brain is affected by the stimulation of its information processing provided by its surroundings (including the opportunity to interact socially). Brains in richer, more stimulating environments, have increased numbers of synapses, and the dendrite arbors upon which they reside are more complex. This effect happens particularly during neurodevelopment, but also to a lesser degree in adulthood. What does this suggest? 9 Aim: To investigate the effect of enrichment or deprivation on the development of neurons in the cerebral cortex in rats Research method: Experiment Procedure: Rats were placed in either a stimulating environment (toys) or a deprived environment (no toys). The rats spent 30 or 60 days in their environment and then they were dissected. Findings: Post mortem studies of the rats´ brains showed that those that had been in a stimulating environment had an increased thickness in the cortex. Aim: To investigate if stimulating environments affect the growth of neurons in rats Research method: Experiment Procedure: Rats were placed in enriched environments beginning at weaning or as young adults. Control group were placed in standard cages Findings: Both age groups raised in enriched environments showed a large increase of the length of dendrites in cortical neurons. According to the principle that states animal research can be used in place of human because of their biological similarities, we can infer that a lack of stimulation (deprivation—such as in oldstyle orphanages) delays and impairs physiological parts of the brain responsible for cognitive development. Research also finds that higher levels of education (which is both cognitively stimulating in itself, and associates with people engaging in more challenging cognitive activities) results in greater resilience (cognitive reserve) to the effects of aging and dementia. 14 15 Such studies suggest that brains are physically sculpted by our environments. Aspects of the brain can be changed as we go through experiences. As a person develops a greater number of skills and abilities, the brain actually becomes more complex and heavier. Research has also suggested that Children who are unable to have certain experiences, will have specific parts of their brain significantly less developed, less intricate, and thinner in comparison to those who have had those experiences. 16 Another way in which the brain and environment interact is through the activity of the recently discovered mirror neurons. Mirror neurons are neurons that fire when an animal performs an action or when the animal observes somebody else perform the same action. This means we subconsciously mimic the actions of others and thus share, to some extent, their experience. How can this be effected by your environment? 17 http://www.ted.com/talks/vs_ramachandran_the_n eurons_that_shaped_civilization.html 18 The proposed mechanism is rather simple. Each time an individual sees an action done by another individual, neurons that represent that action are activated in the observer’s premotor cortex. This automatically induced, motor representation of the observed action corresponds to that which is spontaneously generated during active action and whose outcome is known to the acting individual. Thus, the mirror-neuron system transforms visual information into knowledge. 19 These mirror neurons, as they are known, also allow us to know what another person is feeling, without having to think about it. The discovery of mirror neurons is among the most significant neuroscientific discoveries in recent years. This mean that when you see someone doing something, in your brain you do it too - for instance, when you watch a person running, the bit of your brain concerned with planning to move the legs is activated. 20 When you see another person expressing an emotion, the areas of your brain associated with feeling that emotion are also activated, making emotions transmittable. Emotion mirroring is thought to be the basis of empathy. Autistic people often lack empathy and have been found to show less mirror-neuron activity. Mirror neurons explain why emotion is whipped up in horror film audiences - seeing someone else looking frightened makes you feel scared yourself. 21 http://www.robotcub.org/misc/papers/06_Rizzolat ti_Craighero.pdf 22 23 There are numerous theories/studies that suggest that our cognition(to mean such functions or processes as perception, introspection, memory, creativity, imagination, conception, belief, reasoning, volition, and emotion) interacts with physiological functions (brain parts, neurotransmitters) to guide behavior. This essay should be started by first explaining the interaction between physiology and cognition in all behavior. Examples should be provided to show knowledge and understanding of these interactions. 24 In psychology, cognition is a group of mental processes that includes attention, memory, producing and understanding language, perception, and making decisions. There is an interaction of physiological factors and cognitive factors in many of the behaviors that we experience. One particular behavior is the experience of emotion. 25 Psychologists have long debated the role physiological, and cognitive factors play in emotions. Originally believed to be a physiological experience, research now suggests that emotions are an interaction of both physiological and cognitive factors. Different theories debate the role and primacy of each. For this objective, we will evaluate two theories. 26 Emotions are an individual’s subjective feelings and moods. The term applies to both physiological and cognitive responses to specific stimulus situations. 27 One component of emotions is cognitive processes. Although psychologists differ in the extent to which they emphasize the role of cognition in emotional arousal and expression, there is a general consensus that perception, learning, and memory are all very much involved in experiencing emotions. Listening to music, or looking at a picture often elicits conditioned or learned emotions. 28 29 30 31 32 33 34 35 36 37 The other component of emotions is physiological arousal. When someone describes their anger by saying “the juices were flowing,” this account is close to the mark. The “juices," in the form of epinephrine and other hormones associated with the arousal of anger, probably were flowing. As a result of this increased endocrine activity, we might guess that for a few moments the heart rate increases dramatically, blood pressure probably increased significantly, and breathing may have become rapid and uneven. In other words, there is a physiological response to our emotions. 38 Schacter (1964) was the first theorist to bring together the two elements of physiological arousal and cognition. It is sometimes known as the twofactor theory of emotion. For an emotion to be experienced, a physiological state of arousal is necessary AND situational factors will then determine how we perceive this arousal. 39 In other words, an event causes physiological arousal first. You must then identify a reason for this arousal and then you are able to experience and label the emotion. The strength of physiological arousal will determine the strength of emotion experienced, while the situation will determine the type of emotion. These two factors are independent of each other BUT both are necessary for the emotion to be experienced. 40 We appraise the emotion-causing event while also evaluating what is happening with our bodies. The key process in emotional arousal is how we interpret feedback from our bodies in light of our present situation. 41 So, imagine you are alone in a dark parking lot walking toward your car. A strange man suddenly emerges from a nearby row of trees and rapidly approaches. The sequence that follows, according to the two-factor theory, would be much like this: 1. I see a strange man walking toward me. 2. My heart is racing and I am trembling. 3. My rapid heart rate and trembling are interpreted as fear because of the situation. 4. I am frightened! 42 Why are cognitive labels important in identifying emotions? How can this same physiological response be perceived differently? 43 Physiological responses related to the emotions of fear, anger, love, and jealousy are very similar. Without a cognitive label, we would misinterpret those emotions. M. Grecco/ Stock Boston Excitement and fear involve a similar physiological arousal. 44 Schachter and Singer’s Experiment A classic study by Schacter & Singer ( 1962) supports these ideas. Their study tested the theory that an emotion is made up of cognitive appraisal (labeling the emotion) and physiological arousal (adrenaline and the physical changes it produces). 45 Schachter and Singer’s Experiment The aim of the experiment was to test the twofactor theory of emotion to see if participants exhibited both cognitive and biological reactions to an stimulus. 46 Schachter and Singer’s Experiment A group of 184 male participants were injected with epinephrine, a neurotransmitter (which also doubles as a hormone) that produces arousal including increased heartbeat, trembling and rapid breathing. All of the participants were told that they were being injected with a new drug to test their eyesight (which was false). However, one group of participants were informed of the symptoms the injection might cause (control group), while other participants were not (experimental group). 47 Schachter and Singer’s Experiment Participants were then placed in a room with another participant who was actually a confederate in the experiment. The confederate either acted in one of two ways: euphoric or angry. Participants who had not been informed about the effects of the injection were more likely to feel either happier or angrier than those who had been informed. 48 While Schachter and Singer’s research spawned a great deal of further research, their theory has also been subject to criticism. Other researchers have only partially supported the findings of the original study, and have had times shown contradictory results. Other criticisms of the two-factor theory: Sometimes emotions are experienced automatically before we have time to perceive them. The sample was not representative (all male) and males may have different emotional reactions to females. This therefore makes it difficult to generalize the findings further. 49 50 You need to be able to explain these technologies, what they are used for, and their relative use at the biological level. You also need to give examples of research that use these technologies to demonstrate your knowledge and understanding of each technique. 51 Scientists who studied brain properties and functions many years ago were forced to experiment on animal brains, to study autopsied brains (post mortem) of people who had various cognitive and/or motor impairments, and to compare the behavior of people with normal and abnormal brains. 52 Recent advances in computerized imaging technology have made it possible to non-invasively pass through the skull and brain tissue and observe, amplify, record, rapidly analyze the brain substances and signals that reflect activity in very specific brain regions. This technology has revolutionized brain and mind research, and the diagnosis and treatment of many brain-related diseases and malfunctions. 53 Electroencephalogram (EEG) Magnetic Resonance Imaging (MRI) Positron Emission Tomography (PET) scan Functional Magnetic Resonance Imaging (fMRI) 54 An amplified recording of the electrical waves sweeping across the brain’s surface, measured by electrodes placed on the scalp. AJ Photo/ Photo Researchers, Inc. 55 The electroencephalogram (EEG) is a recording of the electrical activity of the brain from the scalp. The first recordings were made by Hans Berger in 1929 although similar studies had been carried out in animals as early as 1870. The waveforms recorded are thought to reflect the activity of the surface of the brain, the cortex. This activity is influenced by the electrical activity (neurotransmission) from the brain structures underneath the cortex. 56 EEG has been employed clinically for some time as a measure of brain function in the hope of determining and differentiating certain functional conditions of the brain. It is used in patients with cognitive dysfunction (due to low neurological activity and or brain damage), either a general decline of overall brain function or a localized deficit. 57 EEG is used extensively to assess neurological disorders. Abnormal decreases of brain activity, usually associated with large slow EEG waves, can occur with brain damage. After very extensive brain damage there may be no electrical activity recorded from the brain. 58 The EEG patterns change when external stimuli (such as sounds or pictures) are presented. These stimuli cause or evoke a particular pattern of brain activity, called the evoked potential. When we measure a lack of activity during a certain activity, we are able to conclude that lower levels of neurotransmission are taking place in that region of the brain. 59 A more revealing look at the brain is obtained by brain-imaging techniques, which provide pictures or scans of the brain. One such technique is the computerized axial tomograph (CAT) scan. A CAT scan takes thousands of X-ray photographs of the brain while the patient lies still on a table. The patient’s head is placed in the middle of a doughnut-shaped ring. 60 Using a computer, the multiple X-ray images are combined to construct a picture of the brain. How can seeing an actual picture of the brain be beneficial to psychologist at the BLOA? 61 CAT scans are helpful in detecting brain abnormalities, such as swelling and lesions in certain areas. Based on this cat scan, what part of the brain appears to be “abnormal”? What can we assume about the behavior of this patient based on the cat scan? 62 With cat scans (as well as MRI scans) we are better able to understand localization of function in live humans. The patient in the picture suffered from cerebral contusions. This brain damage had a cognitive effect on coordination and movement. They also had difficulty with making sense of memory, managing emotions, and thinking. Thus, we are able to better understand the human brain without the necessity of postmortem studies. 63 Another brain-imaging technique is magnetic resonance imaging (MRI). This technology produces three-dimensional images of the brain’s soft tissues by detecting magnetic activity from nuclear particles in brain molecules. MRI provides greater accuracy in the diagnosis of brain diseases than the CAT scan. 64 Magnetic Resonance Imaging (MRI) has been in widespread use since the early 1980s. It uses magnetic fields , radio waves and computerized enhancement to map out brain structure. MRI scans provide better images of brain structure than CAT scans. 65 66 Doctors often recommend magnetic resonance imaging (MRI) when investigating whether a person has Alzheimer's disease, mainly to rule out other possible causes for cognitive impairment, such as a brain tumor or blood clot. But recent research suggests that MRI could become a key diagnostic tool by revealing changes in the brain even before Alzheimer's symptoms appear. 67 Alzheimer's disease affects the brain in many ways, but one of the most apparent involves an area called the hippocampus. This part of the brain is responsible for memory and processing emotion; it also plays a role in an individual's motor skills. 68 In a small 2008 French study, researchers using MRI to evaluate people with Alzheimer's disease found that the hippocampus in those already diagnosed was nearly a third smaller than average. The hippocampus was 19% smaller in people who had not been diagnosed but were experiencing mental impairment. 69 In the aforementioned study, which involved 74 subjects, physicians reported being able to classify those with Alzheimer's disease and those without symptoms with 84% accuracy based on measurement of the hippocampus. The researchers were accurate 73% of the time when distinguishing between patients without symptoms and those with mild cognitive impairment. Again, however, it's important to remember that this was a small study. 70 This would suggest that MRI scans, when done early on in life, can help to predict and diagnose cognitive disorders such as Alzheimer's and dementia that directly effect specific parts of the brain. 71 The positron emission tomography (PET) scan measures the amount of brain activity. Neural activity in different brain regions is measured by showing each region’s use of glucose, a sugar that is the brain’s chemical fuel. PET scans can reveal which parts of the brain are most active in such tasks as talking or listening to others, reading, listening to music, and solving math problems. 72 A newer technology called functional magnetic resonance imaging (fMRI) produces a picture of neural activity averaged over seconds, not minutes, and the images can identify much smaller brain structures than those in PET scans. 73 Questions? 74