brain and neuropsychology

• brain


  the organ in your head made up of nerves that processes information and controls behaviour.

  
• hemisphere


  half of the brain; if we imagine a person facing forward and then look down on the brain from the top, the right hemisphere is on the right side of the brain, while the left hemisphere is on the left.
• cerebrum

  the upper part of the brain. it is the largest part of the brain where higher processing happens; it includes the cortex.

  
• cortex


  the outer layer of the brain, with lots of folds to increase its surface area for more nerve cells, so that it can control more behavioural functions. the bumps are called gyri and the creases are sulci.

  
• spinal cord


  a pathway of nerves inside the spine, which connects the brain to the rest of the body through the peripheral nervous system. information passes between the brain and the spinal cord through the brainstem.
• brainstem


  the part of the brain that connects the spinal cord to the upper brain, which also controls reflexes.
• reflexes


  actions that are automatic and do not require conscious thought.
• frontal lobe


  the area at the front of the brain responsible for decision-making and impulse control. it also helps control problem solving skills as well as helping us concentrate and pay attention to different activities. towards the back of it is the motor cortex.

  
• motor cortex


  it controls the voluntary movements of the human body. it is located in the rear portion of the frontal lobe, right in front of the central sulcus (the crease that separates the frontal and parietal lobe).

  
• parietal lobe


  associated with perception. it gives us the ability to do things such as recognise faces. at the front of the parietal lobe, there is a large section responsible for our sense of touch. it is right behind the central sulcus, and it is known as the somatosensory cortex.

  
• occipital lobe


  deals with our ability to see. it helps process visual information from our eyes and helps make sense of this information. it is often called the visual cortex.

  
• temporal lobe


  helps us with hearing and understanding sounds, speech, and creating speech. there are important areas involved in both producing and processing sound based information. this is why the temporal lobes are said to contain the auditory cortex. there are also areas that help to control memory functions.

  
• cerebellum


  movement, coordination and balance (our motor skills). it takes information from different senses, our spinal cord, and other parts of the brain and combines them to coordinate behaviour. for example, if we are running and see an object, it sends a message telling our body to move out of the way. the message is sent via the spinal cord telling us to change direction while helping us to keep our balance so we don't fall.

  
• lateralisation of function

  different jobs that are done by each half of the brain; each hemisphere will have different specialist roles that it performs.
• asymmetrical

  the two hemispheres of the brain are not equal in terms of what they do; each hemisphere controls different functions, or plays a larger or smaller role in a particular behaviour.
• corpus callosum

  a thick bundle of nerve fibres connecting the two hemispheres of the brain so they can communicate with each other.
• left hemisphere

  plays a big role in the processing of language. an area in the left hemisphere, known as Broca's area, controls the production of speech; if it is damaged, people might find it difficult to talk. other areas of the left hemisphere are dedicated to the control of our ability to write and to understand language. it also controls your right hand and right visual field. it is known to control logical thinking.
• broca's area

  a part of the left hemisphere of the brain that controls speech production. it is linked to the control of the nerve cells in the face that help us to speak and also the general processing of language-based information.
• right hemisphere

  has a large role to play in our spatial awareness. there are also parts of it that control our ability to recognise and perceive faces. it is often seen as being more creative. it is involved in the processing of music we hear, and also in making sense of visual information that we see. it also controls your left hand and your left visual field. this is because of the crossing over of the upper motor neurons to the opposite site.
• spatial awareness


  the ability to negotiate space and navigate our way around our environment.
• the role of the corpus callosum

  it allows messages to be passed from the left hemisphere to the right hemisphere and vice versa. this makes it easier for the brain to pass messages between the different areas of the brain, making connections between different types of information.
• sex differences in brain lateralisation

  it was always thought that females were better at language skills (left-brain skills), whereas males were felt to be better at spatial skills (right-brain skills), such as imagining what a shape would look like if it was shown from a different angle. there was even some evidence suggesting females may have a thicker corpus callosum, suggesting they may use both sides of their brain for some tasks. males, on the other hand, tend to show dominance for one hemisphere for the same tasks with more activity in one hemisphere than the other, rather than an equal spread of activity.
• strengths of lateralisation as an explanation of sex differences between males and females

  some studies have provided evidence to show that male and female brains may work differently because of how the roles of different areas of the cortex are organised. a study by harasty et al. (1997) suggested that parts of the brain that process and produce language are slightly bigger in females compared to males. another study by rilea et al. (2005) found that males were better at some spatial tasks, especially those that use a lot of activity in the right hemisphere. there is plenty of evidence supporting differences in male and female brains, much of which uses scientific methods such as brain scans and laboratory experiments. these methods allow the research to be well controlled, and help to prevent the interference of extraneous variables. this strengthens the explanation as the research evidence is scientific and so the explanation, developed from this evidence, can also be seen as such.
• weaknesses of lateralisation as an explanation of sex differences between males and females

  while there is some evidence that the right and left hemispheres of male and female brains may work slightly differently, the research has weaknesses. in the rilea et al. (2005) study, for example, males did not always do better than females on the spatial tasks. further to this, there were spatial tasks used in the study that did not use a lot of 'right-brain' activity. so differences in how males and females use the right hemisphere for spatial tasks cannot account for all differences in performance. a study published by sommer et al. (2004) suggested that there was no strong evidence that females used both hemispheres for language tasks, meaning it is not a good explanation for girls being better at language skills than boys.
• central nervous system (CNS)

  the brain and spinal cord, which relays messages from the brain to the rest of the body to instruct it what to do. the sensory nerves in the body send messages to the brain via the spinal cord. the brain processes the information and sends messages to the body down the spinal cord to make the body do something. the spinal cord can then activate your peripheral nervous system.
• peripheral nervous system (PNS)

  the system of nerves that connect the central nervous system (mainly the spinal cord) to the skin, muscles and organs in the body.
• neuron


  a nerve cell that transmits information.
• neurotransmitters


  chemicals found in the nervous system that pass messages from one neuron to another across a synapse. they are released from neurons when a nerve impulse reaches the end of a nerve fibre. the neurotransmitter is then picked up by another neuron to receive the message and possibly continue the nerve impulse.
• types of neurotransmitters


  there are different types of neurotransmitters that all have different jobs inside the nervous system. examples of neurotransmitters include: dopamine, serotonin, and GABA (gamma-aminobutyric acid).
• dopamine


  plays a role in attention and learning. not enough dopamine can make it difficult to concentrate on tasks.
• serotonin


  plays a role in mood. too little serotonin can make people feel depressed.
• gamma-animobutyric acid (GABA)


  plays a role in calming us down. when we feel stressed we produce GABA to relax us.
• synaptic functioning


  messages are passed throughout the nervous system, from one neuron to the next, by a process called synaptic transmission. synapses are tiny gaps between neurons that allow chemical messages to pass between them. an electrical impulse is triggered inside the cell body of a neuron; the neuron then passes a small impulse along the axon towards the end of the nerve fibre. at the end of the nerve fibre is a structure called the terminal button, which is filled with tiny sacs called vesicles containing the neurotransmitters (chemical molecules). when the nerve impulse reaches the terminal button, the vesicles release the neurotransmitter molecules into the synapse. these molecules are then 'grabbed' by the receptors on the next neuron to pass the message impulse on.

  
• synaptic transmission


  the process by which neurotransmitters are released by another neuron, move across the synaptic gap and are then taken up by another neuron.
• synapse


  a gap between two neurons that allows messages, in the form of neurotransmitters, to pass from one cell to another.
• axon


  the long structure that connects the cell body of a neuron to the terminal button at the end of the cell.
• terminal button


  the bud at the end of a branch of an axon containing vesicles. it forms synapses with another neuron to send information.
• vesicles


  small sacs containing neurotransmitter (chemical) molecules.
• receptors


  special sites on neurons that are designed to absorb neurotransmitter molecules.
• neurological damage


  damage to the body's central and peripheral nervous system. small scale brain damage could be where a few neurons in a larger network of neurons are damaged and not working properly. however, if a large part of the brain is damaged, the neurons that would usually have a specific function would stop working. visual agnosia and prosopagnosia are examples on how the brain's ability to process information is affected by brain damage. damage to the pre-frontal cortex also affects behaviour.