Biopsychology model answers

Q1: EEG has been very valuable at helping diagnose conditions such as epilepsy because the difference in brain activity can be easily detected on the screen. However, EEG’s lack precision in measuring individual action potential of neurons as the electrodes are not sensitive enough. It does not allow researchers to tell the difference between activity in locations that are close to one another.   safe way of measuring brain activity; there is no surgery or invasive process;

Q2: The sympathetic-adrenal system is activated. This causes adrenaline to be released from the adrenal glands, which increases heart rate, blood pressure and inhibits the digestive system. A few minutes the parasympathetic branch of the ANS will start to work. This will reduce the “flight or fight” response and bring the body back to normal (homeostasis). This action is known as rest and digest.

Q3: (a)     A (b)     C (c)     D (d)     E (e)     B

Q4: Adrenaline is released from the adrenal medulla in response to activation of the sympathomedullary pathway. It plays an important role in the fight or flight response by getting the body ready for action. The direct effects of adrenaline are increase in heart rate. Adrenaline constricts blood vessels, increasing rate of blood flow and raising blood pressure. It diverts blood away from the skin, kidneys and digestive system and increases blood to brain and skeletal muscle for physical action and for rapid response planning.

Q5: Circadian rhythms have a 24 hour periodicity. The sleep-wake cycle is an example of a circadian rhythm, which dictates when humans and animals should be asleep and awake. The sleep-wake cycle is influenced by Light (exogenous zeitgeber) which provides the primary input to this system, acting as the external cue for sleeping or waking. Light is first detected by the eye, which then sends messages concerning the level of brightness to the suprachiasmatic nuclei (SCN which is the main endogenous pacemaker. When the SCN receives information about a lack of light it causes melatonin to be produces and induces sleep.

Q6: Ultradian rhythms are rhythms that have a cycle length of more than one cycle every 24 hours. Sleep is the ultradian rhythm mostly studied. This cycle alternates between REM (rapid eye movement) and NREM (non-rapid movement) sleep during the night. Sleep and consists of five stages. The cycle starts at light sleep, progressing to deep sleep then starts to become lighter and then into REM sleep, where brain waves activity is similar to when awake and dreaming occurs. This repeats itself about every 90 minutes throughout the night and a person can experience up to five complete sleep cycles each night.

Q7: A: false B: false

Q8: Neurotransmitters can be excitatory or inhibitory. If the neurotransmitter is excitatory then the post synaptic neuron is more likely to fire an impulse. If the neurotransmitter is inhibitory, such as GABA then the post synaptic neuron is less likely to fire an impulse. At the synapse the excitatory and inhibitory influences are summed, if the net effect on the post synaptic neuron is inhibitory, the neuron will be less likely to 'fire' and if the net effect is excitatory, the neuron will be more likely to fire. This is known as summation.

Q9: Problem – random sampling is not necessarily representative and it could be that, by chance the 3 pm group might simply have been better at maths than the 3 am group. The solution would be a matched pairs (matched on maths ability) or repeated measures design with counterbalancing. Problem – use of different maths tests. The maths tests were not standardized and as this is IGD the maths test should have been the same. The only thing that should change is the IV which was 3.am or 3 pm. The solution would be to use the same set of maths problems. Individual differences. Participant variables could be a factor here as the researchers used IGD. Variables such as IQ, age and maths ability would be factors that could influence the results other than the time of day. The researchers could use a repeated measures design to illuminate participant variables but would need to counterbalance with two different maths tests. Other issues, such as individual differences in biological rhythms (‘owls’ versus ‘larks’) confounding results. Such answers should be marked on their merits – is the problem plausible and is the solution sensible?

Q10: A divided field technique could be set up. The patient would be asked to focus on a spot in the middle of their visual field whilst an image/word is projected to the patient’s left visual field (which is processed by the right hemisphere) or the right visual field (which is processed by the left hemisphere). Patients would be required to give a verbal response or a visuospatial response such as drawing what they see.

Q11: The endocrine system is a network of glands across the body that secrete chemical messengers called hormones directly into the blood stream. These hormones then travel to their target organs to regulate many bodily functions. An example of this is adrenaline, released by the adrenal medulla which causes the fight or flight response.