2011 VN'ers Psychology U3 Questions Thread

[Russ]

Yeah, terribly worded.

Your legs are also controlled by your spinal cord, so there's a reason there's less motor cortex there

[Glockmeister]

Yeah, terribly worded.

Your legs are also controlled by your spinal cord, so there's a reason there's less motor cortex there

Well, actually, that's not normally the case. The spinal cords acts as a certain pathway connecting the legs to the motor cortex of the brain. The exception to this is in reflex responses (e.g, you've stepped on a pin, or a hot plate and you need to move your legs out of the painful stimulus quickly). When this happens, it skips the brain and it is the spinal cord directs the movement of the leg.

[iNerd]

The cerebral cortex of the human brain is a much folded layer covering the cerebrum. The advantage of the folding is that
A.   it allows a greater volume and thus number of brain-cells to be contained within the human skull.
B.   it allows greater blood flow to the cortex and therefore more oxygen can be available.
C.   it allows greater blood flow to the cortex and therefore more blood-sugars can be available.
D.   all the above answers are correct.

Lol...?

They put D but A can't be right because it says greater volume - isn't it greater surface area?

[Russ]

Well, actually, that's not normally the case. The spinal cords acts as a certain pathway connecting the legs to the motor cortex of the brain. The exception to this is in reflex responses (e.g, you've stepped on a pin, or a hot plate and you need to move your legs out of the painful stimulus quickly). When this happens, it skips the brain and it is the spinal cord directs the movement of the leg

What about repetitive movements (ie walking)? I was under the impression that the brain would delegate to the spinal cord the role of actually sending APs to the relevant motor units...am I crazy or is this the case?

I guess it also increases the volume of cells but SA is definitely the best wording

[iNerd]

I guess it also increases the volume of cells but SA is definitely the best wording

This is outrageous. VCAA better not be this bloody bad.

[Glockmeister]

I guess it also increases the volume of cells but SA is definitely the best wording

This is outrageous. VCAA better not be this bloody bad.

VCAA isn't usually.

Well, actually, that's not normally the case. The spinal cords acts as a certain pathway connecting the legs to the motor cortex of the brain. The exception to this is in reflex responses (e.g, you've stepped on a pin, or a hot plate and you need to move your legs out of the painful stimulus quickly). When this happens, it skips the brain and it is the spinal cord directs the movement of the leg

What about repetitive movements (ie walking)? I was under the impression that the brain would delegate to the spinal cord the role of actually sending APs to the relevant motor units...am I crazy or is this the case?

I guess it also increases the volume of cells but SA is definitely the best wording

My understanding is that the motor cortex maintains control over the movement and is responsible for sending the signals to the legs via the spinal cord. The only reason why reflexes don't work the same way is because if it did, it would be far too slow and you'd burn your fingers before it pulls out. That's why it goes via the quick way.

[WhoTookMyUsername]

how can it increase volume russ?

[Russ]

I was kind of making an excuse for the question. The ruffling of the brain increases surface area but also the amount of cells, so technically it would increase the amount (volume) of cells present.

If I was writing a SAQ I'd use Surface Area though

[taiga]

why is spatial neglect on the right side of the brain less frequent?

[Slumdawg]

why is spatial neglect on the right side of the brain less frequent?

haha taiga. I already answered her question on fb She gets it now, she said haha.

Here's the explanation in case anyone else wondered what the answer was:

"Okay, well as you may already know your awareness of the world around you is a spatial task and according to our knowledge of hemispheric specialisation spatial tasks are part of the RIGHT hemisphere. That means for someone to have spatial neglect the damage needs to be in the right hemisphere (specifically the parietal lobe of the right hemisphere). That's why people with spatial neglect will ignore the left side, because their right hemisphere is damaged.

You won't find a person with spatial neglect who ignores the right side of their body, because that would mean their ability to be aware of their surroundings is in their left hemisphere which isn't correct.

The ability to be aware of our surroundings is specialised to the right hemisphere, so if your left hemisphere parietal lobe was damaged you wouldn't experience spatial neglect."

[taiga]

why is spatial neglect on the right side of the brain less frequent?

haha taiga. I already answered her question on fb She gets it now, she said haha.

Here's the explanation in case anyone else wondered what the answer was:

"Okay, well as you may already know your awareness of the world around you is a spatial task and according to our knowledge of hemispheric specialisation spatial tasks are part of the RIGHT hemisphere. That means for someone to have spatial neglect the damage needs to be in the right hemisphere (specifically the parietal lobe of the right hemisphere). That's why people with spatial neglect will ignore the left side, because their right hemisphere is damaged.

You won't find a person with spatial neglect who ignores the right side of their body, because that would mean their ability to be aware of their surroundings is in their left hemisphere which isn't correct.

The ability to be aware of our surroundings is specialised to the right hemisphere, so if your left hemisphere parietal lobe was damaged you wouldn't experience spatial neglect."

This is from her

"Slumdawg is god"

[Zafaraaaa]

Please help

Distinguish between stratified samping AND stratified random sampling, and explain it's purpose.

[burbs]

Stratified sampling is dividing the population into strata and selecting a sample that represents all the different strata of the population in the same population.
eg. 50% male 50% female or something.

Random stratified means you identify the stratum then randomly select the participants in the correct proportions.

The purpose is to ensure that the participants best represent the population and ran-strat is the best way to do this and ensure you minimise extraneous variables.

I think.

[totaled]

Please help

Distinguish between stratified samping AND stratified random sampling, and explain it's purpose.

stratified RANDOM sampling is probably what you perceive/expect 'stratified sampling' to be
stratifeid sampling is the smae, except it isnt exactly random, as it is often difficult to find the exact proportions of each 'strata', so they may be chosen out of convenience, to make up the sample in an experiment. I doubt this distinction will ever be assessed aha, vcaa rarely test down to such very fine details, rather the larger concepts, although it is handy to know i guess

[Zafaraaaa]

Oooh okayy thanks =]

Although this multiple choice Question confused me a bit:

A psychologist conducted an experiment to investigate the impact of gender on readiness to help others.  His target population was a first year Psychology class comprising twenty male and ten female students.  The psychologist randomly selected a sample from the target population comprising four males and two females to take part in the experiment.

This method of subject selection is called
A.   stratified sampling.
B.   random sampling.
C.   participant allocation.
D.   stratified random sampling.

[I thought it was D, but it turned out to be A :S Can someone pleasee explain why??]

Thanks in advancee