Biological Approach Flashcards
Define neural pruning
Neural pruning is the process by which unnecessary or unused synaptic connections in the brain are eliminated, making the brain more efficient. This process typically occurs during development, particularly during childhood and adolescence, but can also be observed in response to experience and environmental demands.
Draganski et al procedure
In the study, participants were asked to learn a complex juggling task over a period of three months.
Before and after this training, participants underwent brain scans using magnetic resonance imaging (MRI) to measure changes in their brain structure.
Draganski et al findings
after three months of practice, participants had increased grey matter in areas of the brain associated with visual processing and motor coordination, particularly in the posterior intraparietal sulcus, which is linked to the coordination of hand movements.
However, after participants stopped practicing the juggling task, the increased grey matter gradually decreased, indicating that the neural connections formed during the learning process were pruned away when no longer needed.
This demonstrates neural pruning, as the brain eliminates excess or unused connections to make the brain more efficient and focused on the tasks it regularly performs.
Define Agonists
Agonists are substances that bind to receptors in the brain and activate them to produce a biological response. Agonists can be endogenous (natural) such as neurotransmitters or exogenous (artificial drugs ) that mimic neurotransmitter activity.
Define Antagonists
Antagonists are substances that bind to receptors but block or inhibit their activation, preventing a biological response. Antagonists are often used in studies to help researchers understand the function of specific neurotransmitters in behavior.
Define Neuroplasticity
Neuroplasticity refers to the brain’s ability to reorganize itself by forming new neural connections and increasing dendritic branching in response to learning, experience, or injury. This process allows the brain to adapt to new demands and environmental changes, often resulting in changes to brain structure and function.
Aim of Maguire et al
One prominent example of neuroplasticity in action comes from Maguire (2000), which investigated whether the hippocampus of London taxi drivers differs from non-taxi drivers due to their extensive experience with spatial navigation.
What is VBM
Voxel-Based Morphometry (VBM) measures gray matter volume in the brain
What is pixel counting
Pixel Counting measures the surface area of specific brain structures
Define localization of functions
Localization of functions refers to the idea that specific brain functions are associated with particular regions of the brain; this goes beyond the theory of lateralization, which refers to the specialization of certain functions in one hemisphere of the brain. This concept suggests that different regions of the brain control various cognitive processes such as memory, emotion, and motor skills
Define MRI
MRI is a neuroimaging artifact that uses magnetic fields and radio waves to detect energy emitted by hydrogen atoms in the brain, which vary depending on the type of tissue. This creates a detailed image of brain structure.
Define inhibitory synapses
Inhibitory Synapses are where neurotransmitters decrease the likelihood that the postsynaptic neuron will fire an action potential.
Define excitatory synapses
Excitatory Synapses sre where neurotransmitters increase the likelihood that the postsynaptic neuron will fire an action potential.
Aim of Antanova et al
Antonova et al.’s (2011) study investigated the effect of blocking acetylcholine receptors on spatial memory formation
Procedure of Antanova et al
The study involved healthy male adults in a repeated measures design.
Participants were randomly allocated to receive either an injection of scopolamine (which blocks acetylcholine receptors) or a placebo 70–90 minutes before performing a spatial memory task in an fMRI scanner.
The task, known as the “Arena Task,” required participants to navigate a virtual environment and remember the location of a pole.
The brain activity of the participants was recorded while they performed the task.
After a few weeks, the participants returned and completed the same task but with the opposite treatment (i.e., those who previously received scopolamine now received the placebo and vice versa).
The results showed that participants injected with scopolamine exhibited reduced activity in the hippocampus, a brain region associated with memory formation.
This suggests that acetylcholine agonist is involved in the encoding of spatial memories.
Maguire et al procedure
In Maguire (2000), male London taxi drivers were compared with a control group of right-handed males who did not drive taxis.
The taxi drivers were required to have completed the rigorous “Knowledge” test and held their license for at least 1.5 years, ensuring that they had substantial experience with navigation and spatial memory.
The study used voxel-based morphometry (VBM) and pixel counting to analyze the hippocampal volume in both groups using MRI scans.
The findings showed that the posterior hippocampi of taxi drivers were significantly larger than those of the control group, while their anterior hippocampi were significantly smaller.
These differences correlated with years of taxi-driving experience, with the right posterior hippocampus increasing in size as the taxi drivers accumulated more years of experience. These results suggest that the posterior hippocampus is involved in retrieving previously learned spatial information, while the anterior hippocampus is responsible for learning new spatial layouts.
This study provides clear evidence of neuroplasticity, demonstrating that the brain’s structure can physically change in response to specific environmental demands, such as navigating through the streets of London.
Define neurotransmitters
Neurotransmitters are chemical messengers produced and stored in neurons that transmit signals across the synapse from one neuron to another, influencing various cognitive and physiological functions. Different neurotransmitters have different effects on behavior. One neurotransmitter that plays a key role in cognitive function is acetylcholine, which is essential for memory consolidation.
Aim of Maguire et al (2000)
aimed to investigate whether the hippocampus of London taxi drivers differs from non-taxi drivers due to their extensive experience with spatial navigation
Define neural networks
Neural networks are formed through the process of neuroplasticity, which refers to the brain’s ability to change and reorganize in response to experience, learning, and environmental demands.
Neural networks are formed when neurons connect through synaptic transmission, strengthening pathways that are frequently used and weakening those that are not. A key mechanism in this process is long-term potentiation (LTP), which enhances synaptic strength through repeated activation.
Define Genes
Genes are segments of DNA located on chromosomes within the cell nucleus, that carry genetic information and are passed down from parents to offspring through inheritance. They influence the development of physical traits and can also play a role in psychological traits and disorders. Research suggests that genetic predisposition can make individuals more vulnerable to developing depression, although environmental factors also play a role.
Define genetic similarities
Genetic Similarities refer to the degree to which individuals share common genetic material.
Weissman et al procedure
The participants came from two groups: one with a high risk of depression (where the grandparents had depression) and a control group with no history of depression. Researchers used clinical interviews and diagnostic criteria to evaluate depressive symptoms across generations.
Draganski et al aim
Draganski et al. (2006) conducted a study to investigate the effects of learning a new skill on the brain, focusing on how neural connections are strengthened or pruned
Weissman et al findings
The results showed that grandchildren with two generations of family members with major depressive disorder were significantly more likely to develop depression themselves, compared to those with non-depressed grandparents. Furthermore, children who had a depressed parent but non-depressed grandparents had a much lower risk, suggesting that the genetic risk of depression is stronger when it is present across multiple generations.
