Psychology What are two kinds of evidence that consciousness depends on a functioning brain? To start with, damage to the alerting areas of the brain, the brain stem and the midbrain, most likely can result to loss of consciousness. The first evidence is that consciousness cannot exist without the cortex working accordingly. Without this part, it would not be possible to comprehend speech, plan, move, solve problems, or express emotions. All these are aspects of consciousness.
Second evidence is the brain stem. The hypothalamus is responsible for the sleep cycle; therefore, the suprachiasmatic nucleus controls the preoptic nucleus that induces sleep. By inhibiting the reticular activating system in the brain stem, the preoptic nucleus makes the cortex to sleep. Therefore, consciousness depends on normal working of the brain.
2. Describe three differences between epsp’s and action potentials.
Excitatory postsynaptic potentials
Action potentials
EPSPs occur on the cell bodies (of the neuron) as well as the dendrites. Excitatory postsynaptic potentials results from the activation of ions on the postsynaptic channel. The channel opens, giving way for the ions to move across the membrane, which causes depolarization
Contrary, action potentials responses are initiated in the axon hillock and are not degraded as they are propagated down the axon.
In this case, due to degradation of the activation, the amplitude decreases as the change in voltage moves far from the post-synaptic channel.
The action potential does not undergo degradation during transfer; hence, the amplitude is the same.
Many EPSPs that simultaneously arrive at axon hillock are responsible for generation of a single action potential.
An action potential is transferred through neurotransmitters, to a postsynaptic neuron
3. What organ is lateral to the amygdala, posterior to the eye, and has two windows?
Inner Ear
4. How may a drug’s action at a synapse explain its effects on behavior?
A drug interferes with the normal neurotransmission. Therefore, a drug alter how neurons communicate since it dopamine mediation of neurons is interfered with. A drug can affect the synapse by increasing the neurotransmitter in the synaptic space. This may result to an increase in the action potential, hence amplified behavior such as feeling of pleasure. Sometimes, drugs may interfere directly with the postsynaptic receptors.
While some drugs block, others activate the receptors. In this case, a drug can affect the brain by inhibiting the neuromodulator from binding with the required receptor, therefore blocking the part responsible of sleep from causing sedation. Drugs such as LSD blocks the dopamine transporter between serotonin receptors; thus resulting to change in moods and eating. Finally, a drug can interfere with the removal of neurotransmitters contained in the synapse. Such a drug blocks the dopamine transporter, which may result to euphoria due to accumulation of dopamine.
5. How would you describe the difference between what the retina does and what the striate cortex does?
The retina acts as the interface to the brain by transforming light to electrical impulse. On the other hand, striate cortex receives translated information and converts it to actual perception of the environment.
6. Describe how the auditory system encodes the frequency of a sound.
To encode sound, the auditory system decomposes the amplitude signal that arrives at the ear into several bands of frequency with each frequency being approximately an algorithmic function of the length from the stapes.
Hara, T. J. & Zielinski B. S. (2006). Sensory systems neuroscience. Amsterdam, Netherlands Boston, MA: Elsevier Academic Press.