Introduction to Psychology Chapter 4 (Neural Control of Behaviour) Flashcards
Who was the first to see the real function of behaviour and what did people think before him
Hippocrates was the one who discovered the real function of the brain, people before him thought it’s function was to cool the blood
What’s the central nervous system and what’s its function
The central nervous system consists of the brain and the spinal cord. It integrates and synthesises neural information.
What are the extensions from the nervous system called and what is their function.
One extension is called a nerve, together they make up the peripheral nervous system, which relays information from other parts of the body
What are the three types of neurones and their function
- Sensory neurons: make nerves and carry information from sensory organs to central nervous system
- Motor neurons: also make nerves and carry information from the central nervous system to operate muscles and glands
- Interneurons: only in the central nervous system, carry messages from one set of neurons to another
Describe the structure of a neuron
A typical neuron has a cell body which contains the nucleus, dendrites which recieve the input into the neuron, and an axon which carries the neurons output
Explain the resting and action potential of a neuron. Also describe de and repolarization
Because of a inbalance between sodium and potassium ions outside and inside the cell the resting potential is at -70 mV. As soon as an action potential is engaged because of a signal, the cell membrane allows sodium to bass through, which results in the cell relieving the negative charge. Because of diffusion the potassium ions leave the neuron, resulting in a negative charge again. Here the sodium potassium pump restored the original situation.
What determines the speed of the electrical conduct in axons
The diameter (large=faster) and the existence of a myelin sheath.
Explain how synaptic transmission works
When an action potential reaches the presynaptic membrane, vesicles with neurotransmitters release them into the synaptic cleft.
This causes the neurotransmitters to open sodium channels, which causes the postsynaptic neuron to conduct a depolarization, if the threshold is reached.
What are the four big neurotransmitters and there role.
Dopamine (movement and reward motivated behaviour)
Acetylcholine (activation of muscles and information processes)
Serotonin (many behaviours like sleep and mood)
GABA (weakens or alles down signals)
How is the strength of a signal conducted
By the frequency of action potentials per second
Explain brain development in neurons
The most neuron production is until the age of 2 and 4, after this the neurons engage in selective cell death and pruning, which means an adult has fewer neurons than a child.
Instead of growing in number, neurons are more like sculpted, which means the overproduced neurones are shaped and developed.
What are mirror neurons and what are their functions.
Mirror neurones are neurones that are active both when a subject watches a behaviour and when it does it itself. It may be the basis for imitation and social learning.
What are the three main categories in methods for identifying specific brain functions.
- Observing behaviour deficits when a part of the brain is damages
- Observing behavioural effects of artificially stimulating brain parts
- Recording changes in brain activity when a person is engaged in particular behaviour
Explain TMS, EEG and fMRI
TMS: temporarily disrupts activity in brain areas by magnetic fields
EEG: record electrical activity by electrodes placed on the skull
fMRI: produce brain images by looking at blood flow
Explain the two hierarchically organizations of the nervous system
Sensory perceptual hierarchy: data processing, from bottom to top
Motor control hierarchy: movement control, from top to bottom
Explain two kinds of nerves
Cranial nerves (directly from brain): 12 pairs connected to specialized sensory organs of the head Spinal nerves (project from spinal cord): 31 pairs connected to the rest of the body --> somatosensation
What are the two divisions in the motor system
- Somatic division: act on skeletal muscles
- Autonomic division: act on internal organs and glands and have the sympathetic division (prepare for fight and stress) and the parasympathetic division (growth and Energie conserving).
When the spinal cord is damaged, what determines what is paralised and what not
The location of the damage is important. If it is near the head the person is completely paralised because no spinal nerve can reach the brain. If the damage is lower, some functions like arms still work.
What is a flexion reflex and what are pattern generators
It is a reflex which causes a limb to be pulled of something towards the body.
Pattern generators produce rythmic movement like walking or flying.
They do not require the brain.
Describe the brainstem with it’s functions and reflexes
The brain stem is the lower part of the brain without the spinal cord. It is the medula, pons and midbrain. It is similar to the spinal cord but more complex as it has functions like postural (balance) and vital (breathing) reflex. It also governs most of the species typical behaviours.
What is special about an animal whose nervous system is cut through just above the brain? (Brain stem animal)
It produces most of the species typical behaviours normaly, but it doesn’t make decisions because all of its responses are initiated through immediate stimuli. It works like a machine
Which parts of the brain are involved with coordinated skilled movements and how do they differ
The basal ganglia (more in a feedback sense as the movement progresses) and the cerebellum (more in more rapid movement)
What are the main functions of the thamalus
It is like a relay station in the brain, which connects various parts of the brain with one another.
It also plays a role of the arousal of the brain a whole
What are the structures of the limbic system and their functions. Also explain what it is connected strongly with
- Amygdala: regulation of basic drives and emotions
- Hypocampus: spatial location and encoding certain memories
The limbic system has a strong connection to the hypothamalus (regulate emotions), the basal ganglia (to help translate emotions into action) and the nose (smell has big effect on emotions)
What are the three functions of the hypothamalus
It helps to regulate the internal enviroment of the body by
- Regulating the autonomic nervous system
- Controlles certain hormones
- Affects certain drove states (hunger and thirst)
–> four Fs (fighting, fleeing, feeding, fucking)
How is the celebral cortex divided
It is divided into two hemispheres, which are also divided into 1. Occipital 2. Temporal 3. Parietal 4. Frontal Lobes
Explain the three functional categories of of the cortex regions
- Primary sensory areas (recieve signals from sensory nerves) with visual auditory and sematosensory area
- Primary motor area (sends axons down the motor neurons
- Association areas (recieve input from sensory areas for complex processes like perception thought and decision making) which is all the rest of the cortex
What is the function of the prefrontal cortex
It’s engaged in executive functions like regulating attention or determining what to do with gathered information. It also plays a central role in planning.
Explain the general flow of information in the cortex
- Sensory areas give association areas information
- Association areas analyse information and come up with plans what to do
- The motor cortex puts plans into actions
What are hormones and their functions
They are chemical Messengers that are secreted into the blood. They influence behaviour like in growth of bodily structures and metabolism, but they also influence brain functions like moods. They can be short and longterm
Explain the brain- pituary- adrenal response way
A stimulus causes the brain to interpret an emotion.
The hypothamalus signals the pituary gland to produce hormones.
The hormones travel down to the adrenal gland.
The adrenal gland secretes new hormones which act in adaption for emotion
Explain how hormones influence male sex drive
Castration removes sex drives after couple of days but testesterone increases it.
In humans winning a game or competition increases testesterone and increases sex drive, the opposite does the opposite.
Explain how hormones influence the sex drive in females
In most mammals there is only a sex drive at a special time during the ovarian cycle.
In humans this cycle influences it but not as much.
How are both hemispheres connected in the cerebral cortex
They are connected by the corpus callosum, a massive bundle of axons
How are the two hemispheres in the cerebral cortex similar
They are symmetrical in their primary sensory and motor functions, but contralateral.
Explain the differences in the left and right hemisphere
They differ in association areas.
The left hemisphere produces language in most people.
The right hemisphere is superior in visuospatial tasks.
What do studies about Broca’s area suggest it does
It articulates words and sentences in a fluent manner and transforms complex sentences into simple ones
How can the brain structure change and give an example how
It can change during it’s usage by skill development, exploration and general learning.
Examples are rats in enriched enviroments, the brain of blind people and the brain of taxi drivers
Explain long-term potentiation
When a synaptic depolarization occurs, the synapsis strengthens by gaining more neurotransmitters. This initiates learning as the postsynaptic neuron is activated more often even though the stimulus is the same.
This may be the basis for learning and conditioning
How is the human brain different from other species
The human brain has the largest brainmass in proportion to it’s bodyweight. The largest grow here was in the association cortex.
