Reaction Time Researchers wanted to assess the effect of low a...

Question

Reaction Time Researchers wanted to assess the effect of low alcohol consumption on reaction time in seniors, believing that even low levels of alcohol consumption can impair the ability to walk, thereby increasing the likelihood of falling. They identified 13 healthy seniors who were not heavy consumers of alcohol. The experiment took place in late afternoon. Each subject was instructed to have a light lunch and not to drink any caffeinated drinks in the 4 hours prior to arriving at the lab. The seniors were asked to walk on a treadmill on which an obstacle would appear randomly. The reaction time was measured by determining the time it took the senior to lift his or her foot upon the appearance of the obstacle. First, each senior walked the treadmill after consuming a drink consisting of water mixed with orange juice with the scent and taste of vodka. The senior was then asked to drink two additional drinks (40% vodka mixed with orange juice). The senior then walked on the treadmill again. The average response time increased by 19 milliseconds after the alcohol treatment. The researchers concluded that response times are significantly delayed even for low levels of alcohol consumption.

f. Why do you think the researchers used a drink that had the scent and taste of vodka to serve as the treatment for a baseline measure?

f. Why do you think the researchers used a drink that had the scent and taste of vodka to serve as the treatment for a baseline measure?

Accepted Answer

Hello there, today we are going to solve the following practice problem together. So first off, let us read the problem and highlight all the key pieces of information that we need to use in order to solve this problem. A team studying the effect of a mild sedative on manual dexterity recruited 16 older adults. Each participant first completed a pegboard test after drinking a beverage that looked and smelled like the sedative but contained no active drug. Then each participant took a low dose of the sedative and repeated the test. Why did the researchers give the appearance matched beverage before the actual sedative dose? OK, so it appears for this particular problem we're given a scenario, and in this scenario we have a study that is being performed, and the study once again is on the effect of a mild sedative on manual dexterity, and they tested it on 16 older adults. And each participant was asked to complete a pegboard test after drinking a beverage that looked and smelled like the sedated but con but contained no active drug. And as we should recall, when we do something along the lines of this particular approach, once again, if we're giving a participant something that looks like the sedated but isn't the sedative they're receiving, which you've probably heard this term before, a placebo. And it appears that they're giving the participants a placebo first before they actually give them the sedative dose. So they before they actually give them the actual sedative that they're testing. And we're asked to determine based on this information that is provided to us by the prom itself, we're asked to determine why did the researchers give the appearance matched beverage, the placebo, before the actual sedative dose. So why did the researchers do this? This is what we're ultimately trying to solve for. So now that we know what we're ultimately trying to solve for, our first step that we need to take is we need to recall, based on our prior knowledge, what what type of experimental design principle is being used in this particular experiment. So what experimental design principle is being used in this problem. So, as we should recall, we need to note that the blinding principle is being used. So they're being blinded. So what does that mean? So since we're using this blinding principle, that means that participants are unaware of the treatment allocation, meaning who's receiving the placebo and who's not receiving the placebo, for example. So our second step now is we need to recall and apply the blinding principle. So we need to note that when we give in an appearance, so once again when we're giving an appearance matched non-active drink, the placebo, it makes the participants unable to tell whether they consume the active sedative or a placebo. So with that in mind, for our 3rd step, we need to note that we need to state and recall, based on our prior knowledge what the confound controlled variable is. So the expectancy placebo effect, so we need to note that the belief about receiving treatment can alter performance. So if someone knows that they're receiving the drug, they might. Psychologically think that their their performance is worse when in reality if they don't know if they're receiving the active drug or a placebo, it makes them more open and it doesn't put any damper on the data. So with that in mind, our fourth step now is we need to. Once again, recall and apply the confound control. So we need to note that matching taste and smell prevents changes in performance due to belief rather than the drug's pharmacology, so rather than the farm's actual drug makeup, because once again, since the placebo smells and tastes similar to the actual sedative, the individual participant doesn't, won't be able to tell. The apart, so they won't be able to tell if they're receiving the placebo or if they're receiving the actual drug. So, that is the that's the confound control. So now, moving right along here to our 5th step now. We need to recall and state the internal validity goal. So we need to, once again, based on our prior knowledge, we need to isolate the pharmacological effect by holding sensory, once again, holding the sensory sight, taste, smell, etc. cues constant. So we need to hold the sensory cues constant. So with that in mind, our 6th step now is our final step, and we can make our final conclusions. So as you should note, holding sensory cues constant increases internal validity, makes the experiment more valid overall. So observed changes in dexterity are attributable to the sedative itself, not to the expectancy or sensory differences. So with that in mind, Our correct and final answer without a doubt, will be the following to blind participants and control for expectancy and sensory cues isolating pharmacological effects, and that's it. That is our correct and final answer. Thank you so much for watching. Hopefully that helped, and I can't wait to see you in the next video. Bye.

Key Concepts

Placebo Effect

Control Group and Baseline Measurement

Experimental Design and Blinding

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