Measuring Mental Chronometry: A Qualitative Study

The purpose of these three distinct methods of measuring mental chronometry is to separate the subcomponents that theoretically comprise a mental reaction RT (O'Shea & Bashore, 2012). The first method, referred to as a-method, actually originated from work done by an astronomer Aldof Hirsch (Canales 2001). Hirsch’s studies were conducted in the 1860’s and consisted of repeated exposure of a single stimulus to a subject. The subjects were simply instructed to give a fixed response when they perceived the stimulus. The assumption was that the RT, being the time from presentation to response, was a representation of the time needed for the processes associated with transmission of basic stimuli and the activation of motor information through the nervous system. This was a process that did not involve any decision making regarding the stimulus given and choice of response and due to these task restrictions, this type of stimulus-response paradigm is termed ‘simple reactions’. The next method Donders proposed was referred to as b-method. This method included a choice reaction in addition to the simple reaction of a-method. These studies involved having subjects discriminate between two distinct stimuli, each of which having a distinct response association. Simply put, the difference between

Wundt used the core ideas established by Donder and added the d-method to the existing a, b and c-methods (Wundt 1880/1969). Subjects in Wundt’s lab were asked to give the same response to multiple different stimuli with an additional instruction to first recognize (or “apperceive” as Wundt termed it) the stimulus before responding to it. The addition of this recognition task was hypothetically a way to measure pure discrimination. Wundt claimed that his d-method was a more accurate measure for stimulus discrimination than Donders’ c-method, and thus an improvement on the RT