Week 3: Inferential Goals and Brainstem and Cerebellum Function Flashcards
(36 cards)
What is scientific inference in psychology?
Scientific validation of ideas relies on making inferences based on available evidence
Data are not all created equal! - Differences in “quality”
Inference requires judging how strongly data support a claim
What are the requirements for making an inference?
Evaluating the quality of the evidence
Does the measure assess what the researcher says it assesses?
Is the evidence reliably reproducible?
Is the evidence measured quantitatively and objectively?
Evaluating how the evidence relates to theory
Is the evidence consistent with one theory or multiple theories?
Do any theories fail to explain the evidence?
What is a quantitative measurement?
Allows us to put a numerical value on a measurement
“Tall” is no longer subjective or relative
Permits objective measurement by others
Perhaps most importantly, quantitative measurement allows for comparison
Of groups of individuals
Of the same individual through time
What do we do with samples and populations and what are the potential pitfalls?
In most cases, we measure something about a sample of people and seek to form generalized conclusions about the population at large
What is true of the sample/population need not be true of the individual
What is true of the sample need not be true of another sample (even if both are drawn from the same population)
What two factors should measures contain for valid inferences?
Measures should be both reliable and valid
What is reliability?
Refers to how “repeatable” or consistent a measure is
If you were to assess the same construct in the same way using the same method of measurement, do you tend to get the same results?
What is Validity?
Refers to the degree to which a measure assesses the thing it is purported to assess
Is the construct you seek to measure actually related to the measurement?
What was the hot topic of the 19th century that was discussed?
Racial hierarchy, tried to use cranial capacity to determine that whites were smarter. Used mustard seeds but was not repeatable and then used buckshot.
What was the problem with the cranial capacity issue in terms of reliability and validity?
Problem: Cranial capacity does not really relate to intelligence… It’s not the size, it’s how you use it
But cranial capacity does relate to overall body size
Morton’s measure is conflated with body size (and potentially nutrition, etc.)
If the measure is not a valid reflection of the construct of interest, neither are the inferences based on the measure.
What are the three measures of central tendency?
Mean (average score)
Median (the “middle” score in a distribution)
Mode (the most common score)
What are the measures of variability?
Range Measures
Standard Deviation
What can occur between the use of different measures?
Quantitative measurement provides the basis for making defensible scientific inferences that are grounded in data
However, choosing an appropriate measure is not always straightforward—measures must be reliable and valid
Even with good measures though, there is a problem that is created by variability of data across different samples
How likely would a difference be between a treatment and control group of an unsuccessful drug?
A truly ineffective treatment would mean both groups score the same
So a large difference would be very unlikely if the treatment were ineffective
If we see a large difference, conclude the treatment is effective
What can alter the values of two sample groups?
Due to variability in samples though, the groups won’t have exactly the same mean score even if the treatment is ineffective
Usually small differences, sometimes positive, sometimes negative …but sometimes a very large difference will occur due to chance
Why are multiple studies needed?
False positives, cause the wrong effect to be accounted for.
What is the difference between practical significance and statistical significance?
Differences that are larger than would be expected by chance are considered to be “statistically significant”
This is a separate issue from “practical significance” (useful result).
What are some of the issues relating evidence to theory?
Issues when evaluating scientific claims based on statistical evidence
Can another theory explain the same data?
Are there theories that cannot explain the data?
If other theories can explain the same data, future work will need to try and distinguish between those theories!
If there are theories that are unable to explain the current data, they may need to be modified, or potentially abandoned
What is the brainstem/ANS associated with?
States of consciousness
What is the Cerebellum/Motor System associated with?
Feedback control of movement
What comprises the central nervous system (CNS)
Brain and spinal cord
What comprises the peripheral nervous system (PNS)
Somatic Nervous System
– Voluntary
– Motor and Sensory
Autonomic Nervous System
– Involuntary
– Heart-rate, respiration, sweating
– Stress, arousal, “fight-or-flight”
What are the two divisions of the ANS? (autonomic nervous system)
Sympathetic Nervous System – Emotional arousal, stress, fear – “Fight or Flight” response – Increases heart-rate, respiration, perspiration, pupils dilate.
Parasympathetic Nervous System – “Rest and digest” – Lowers heart-rate, respiration – Increases stomach, intestine activity (digestion) – “opposes” the sympathetic nervous system
What are some functions of the Brainstem
Autonomic nervous system functions
Relay between cortex and spinal cord cortex and cerebellum
What comprises the Brainstem?
Medulla oblongata, pons, and midbrain
