When asked, What is the most important part of an experiment?, some will tell you that it lies in careful, considered deliberation about the design of the study, and being able to accurately tease apart alternative explanations of the results; others will say that emphasis should be placed on technical finesse, statistical competence, and strictly adhering to the rules governing good experimental behavior, including correcting for your critical p-value every time you peek at the data - each viewing like another lashing from the scourge of science.
However, what these people fail to mention is the selection of subjects, which, if overlooked or neglected, will render all of the other facets of your experiment moot. Good subjects provide good data; or, at the very least, reliable data, as you will be certain that they performed the task as instructed; that they were alert, awake, and engaged, and that therefore any issues with your results must be attributed to your design, your construct, or technical problems, but that any problems due to the individuals in your experiment must be ruled out.
To honor this observation, I am constantly on the lookout for fresh cerebrums to wheedle and coax to participate in my studies; during my walk to work I observe in a nearby pedestrian a particularly promising yet subtle eminence on the frontal bone, and silently estimate the amount of cubic centimeters that must therefore be located within Brodmann's Area Number Ten; I sidle up to a young girl at the bar, and after a few minutes of small talk and light banter, playfully brush aside a few unruly strands of her hair and place it behind her ear, taking the opportunity to lightly trace the arc of her squamous suture with my finger, feel the faint pulse of her temporal artery, and fantasize about the blood flowing to the auditory association cortex in response to strings of nonsense vowels. "Do you like playing with my hair?" she asks coyly. "Yes," I manage to stammer, roused from my reverie; "It is beautiful - Beautiful!"
There is one qualm I have with selecting good subjects, however. Often they are people I know, or they are referred by reliable friends, so that I have little doubt that they will be able to successfully carry out their charge. Often they are young, college-aged, healthy, right-handed, intelligent, motivated, and desperate for cash; and as I think about the generalizability of my results, I cannot help but conclude that my results are only generalizable to people like this. A great number of people, either not having enough regard to follow the instructions, or not neurotic enough to care about how they do on the task as they would on a test, perform at a suboptimal level and are thereby excluded; else, they are not even recruited in the first place. This becomes more of a concern when moving beyond simple responses to visual and auditory stimuli, and into higher-level tasks such as decision-making, and I begin to question what meaning my results have for the great mass of humanity; but then I simply stir in more laudanum into my coffee, drink deep from the dregs of Lethe, and sink into carefree oblivion.
In any case, once you have found a good subject, odds are that they also know good subjects; and it is prudent to have them contact their friends and acquaintances, in order to rapidly fill up your subject quota. However, when this approach fails me, and I am strapped for participants, I try a viral marketing approach: As each subject is paid about fifty dollars for two hours of scanning time, upon completion of the study and payment of the subject, I request that they convert their money into fifty one-dollar bills, go to some swank location - such as a hockey game, gentleman's club, or monster truck rally - and take a picture of themselves holding the bills spread out like a fan in one hand and a thumbs-up in the other, while underneath the picture in impact font are the words ANDY HOOKED ME UP. This leads to a noticeable spike in requests for participating in my study, although not always from the clientele that I would like.
However, what these people fail to mention is the selection of subjects, which, if overlooked or neglected, will render all of the other facets of your experiment moot. Good subjects provide good data; or, at the very least, reliable data, as you will be certain that they performed the task as instructed; that they were alert, awake, and engaged, and that therefore any issues with your results must be attributed to your design, your construct, or technical problems, but that any problems due to the individuals in your experiment must be ruled out.
To honor this observation, I am constantly on the lookout for fresh cerebrums to wheedle and coax to participate in my studies; during my walk to work I observe in a nearby pedestrian a particularly promising yet subtle eminence on the frontal bone, and silently estimate the amount of cubic centimeters that must therefore be located within Brodmann's Area Number Ten; I sidle up to a young girl at the bar, and after a few minutes of small talk and light banter, playfully brush aside a few unruly strands of her hair and place it behind her ear, taking the opportunity to lightly trace the arc of her squamous suture with my finger, feel the faint pulse of her temporal artery, and fantasize about the blood flowing to the auditory association cortex in response to strings of nonsense vowels. "Do you like playing with my hair?" she asks coyly. "Yes," I manage to stammer, roused from my reverie; "It is beautiful - Beautiful!"
There is one qualm I have with selecting good subjects, however. Often they are people I know, or they are referred by reliable friends, so that I have little doubt that they will be able to successfully carry out their charge. Often they are young, college-aged, healthy, right-handed, intelligent, motivated, and desperate for cash; and as I think about the generalizability of my results, I cannot help but conclude that my results are only generalizable to people like this. A great number of people, either not having enough regard to follow the instructions, or not neurotic enough to care about how they do on the task as they would on a test, perform at a suboptimal level and are thereby excluded; else, they are not even recruited in the first place. This becomes more of a concern when moving beyond simple responses to visual and auditory stimuli, and into higher-level tasks such as decision-making, and I begin to question what meaning my results have for the great mass of humanity; but then I simply stir in more laudanum into my coffee, drink deep from the dregs of Lethe, and sink into carefree oblivion.
In any case, once you have found a good subject, odds are that they also know good subjects; and it is prudent to have them contact their friends and acquaintances, in order to rapidly fill up your subject quota. However, when this approach fails me, and I am strapped for participants, I try a viral marketing approach: As each subject is paid about fifty dollars for two hours of scanning time, upon completion of the study and payment of the subject, I request that they convert their money into fifty one-dollar bills, go to some swank location - such as a hockey game, gentleman's club, or monster truck rally - and take a picture of themselves holding the bills spread out like a fan in one hand and a thumbs-up in the other, while underneath the picture in impact font are the words ANDY HOOKED ME UP. This leads to a noticeable spike in requests for participating in my study, although not always from the clientele that I would like.
