Session 145

This week, we continue our breakdown of Blueprint MCAT (formerly Next Step Test Prep)’s full-length 10 with Passage #9 from Psych/Soc.  We’re joined once again by Clara from Blueprint MCAT (formerly Next Step Test Prep).

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[02:05] Passage 9

Becoming a skilled musician requires considerable practice and this kind of learning relies on multiple faculties (e.g. perception, memory, and motor abilities). According to previous fMRI studies, the functional changes associated with musical training take the form of stronger activation in the temporal cortex (particularly the middle temporal gyrus) and somatosensory areas.

A study was performed to explore the impact of musical expertise on both functional and structural modifications of the brain. For this purpose, researchers selected 20 young musicians who had been playing music without interruption until the time of the study (number of years of practice: 15.3 +/- 3.67) and 20 young non-musicians. Participants were scanned using fMRI during a musical semantic memory task in which they had to rate the familiarity of 60 melodies (purely instrumental tonal excerpts) on a 4-point scale (from “non-familiar” = 1 to “extremely familiar” = 4).

Significant differences (p<0.001) were found in the number of melodies reported as unfamiliar between non-musicians and musicians. As expected, non-musicians judged more melodies to be totally unfamiliar and musicians judged more excerpts to be extremely familiar. In both musicians and non-musicians, familiarity increased activity in an extended network including left motor areas, the right cerebellum, and the left inferior parietal gyrus. Musicians showed greater activity in the bilateral anterior portion of the hippocampus and the bilateral superior temporal areas. Further analyses confirmed that the hippocampus is more strongly involved in musical familiarity judgment tasks in musicians than it is in non-musicians, regardless of gray matter density differences between the two groups.

Following the scanning session, a debriefing session was proposed to determine whether the melodies had evoked personal memories or mental imagery. This debriefing revealed that the musical excerpts evoked personal memories in 85% of musicians but in only 30% of non-musicians.

[04:42] Question 48

Personal memories evoked by musical excerpts would fall under which of the following categories?

1. Episodic memory
2. Semantic memory
3. Short-term memory
4. Long-term memory
5. I and III only
6. I and IV only
7. II and III only
8. II and IV only

Clara’s insights:

The correct answer here is B. Memory is highly tested on the MCAT so it’s important to know these terms.

In particular, episodic memory is the memory of events that happen to you during your life. Semantic memory would relate to facts like if the sky is blue or that 2×9=18.

[07:34] Question 49

Which of the following additional findings would NOT be supported by the data presented in the passage?

1. Musicians store music-related memories in long-term memory to a greater extent than non-musicians.
2. So-called “muscle memory” plays a role in potentiating memories of melodies.
3. Brain areas involved in regulating voluntary motion are involved in memories of melodies in musicians but not in non-musicians.
4. Episodic memories may be linked to procedural memories.

Clara’s insights:

The correct answer here is C. You might get tripped up with answer choice A thinking musicians and non-musicians are both going to store music-related memories in their long-term memory.

But the key is paragraph 3. It specifically says, “Musicians showed greater activity in the bilateral anterior portion of the hippocampus and the bilateral superior temporal areas.”

Then it further says, “that the hippocampus is more strongly involved in musical familiarity judgment tasks in musicians than it is in non-musicians.”

The hippocampus is the site associated with long-term memory.

These answer choices are totally independent of each other. So you have to evaluate each of them separately. This is a great place to prove which answer choices are wrong. For instance, C is not supported because it draws this distinction that it doesn’t exist.

And looking at answer choice D, procedural memories are memories of how to do different things like playing the piano. And this could be linked to episodic memories.

[14:07] Question 50

If a musician experienced a lesion in the cerebellum, which of the following functions would be most affected?

1. Ability to distinguish tones
2. Immediate emotional reactions to melodies
3. Recognition of familiar memories
4. Ability to play music on the instrument of their choice

Clara’s insights:

The correct answer here is D. If you know what the different areas of the brain do then answering this would be super easy.

Cerebellum = movement.

Know the different areas of the brain and what they do.

[15:30] Question 52

The fMRI activation patterns obtained from the non-musicians functioned as:

1. A control variable only.
2. A dependent variable only.
3. An independent variable only.
4. More than one of the above.

Clara’s insights:

The correct answer here is D. B and C are opposite of each other so if it’s not one thing, then it has to be the other. But the reason D is the answer is because the patterns are both a control variable and a dependent variable.

We’re measuring the fMRI patterns and the dependent variable is what we’re essentially measuring. We’re measuring the changes in response to changes in an independent variable.

[19:22] Blueprint MCAT (formerly Next Step Test Prep)

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