1.3 Research Methods in Psycholinguistics
Psycholinguistics employs a number of ways understand language. These range from observational studies, speech error analysis to experiments and neuroimaging techniques. We also use computational models to simulate our theories about the language system. This section will explore some of the techniques employed by researchers. However, keep in mind that we are always developing new techniques to understand how language works.
Mental Chronometry
The study of reaction time on cognitive tasks is a common psychological paradigm in trying to infer the duration, sequence and content of cognition. As seen in Figure 1.5, reaction time (or RT) is measured as the time between the onset of a stimuli and the response by the participant. The mean and the variance of reaction times are considered useful indices on processing speed. The most common form of reaction time experiments are button presses. However, eye movements and voice onset (in repetition and reading tasks) can also be employed.
One of the most popular reaction time paradigms is called priming. Priming is used in almost all areas of psychology. The basic idea is that if two things share some cognitive or psychological attribute, they will either facilitate or interfere with each other. However, it they do not share such similarities, there will be no such effect. For example, it is easier to recognize the word DOG if you have already seen the word CAT. This can be a kind of sematic priming in that both words belong to the same semantic category (ANIMAL). Such an effect is known as facilitation while the interference of slowing down of such an effect if known as interference.
As seen in Figure 1.6, the reasoning behind priming effects can be modelled as a web of interconnected ideas or concepts in the mind. Concepts that are connected semantically (dogs and frogs are both animals) or phonologically (dog and bog end with similar sounds) are more likely to facilitate priming. In Figure 1.6, sematic connections are indicated with straight lines while phonological connects are indicated with dotted lines. The idea is that encountering a stimulus (by seeing or hearing it) will not only activate that concept in the mind but also partially activate connected concepts to some degree. As such, when any one of those connected concepts is presented next, they will be retrieved quicker because they have already been partially activated (or primed) by the previous activation.
Lesion Studies
As the brain is a vulnerable organ, it can be damaged by external or internal trauma. If blood flow and oxygen supply is constricted even for a few minutes to neurons they begin to die. These sites of damage are called lesions. Such trauma can be from accidents, strokes, brain surgery, or the ingestion of certain toxins. Examining these lesions and associating them with the behavioural limitations of such patients can provide valuable information about which regions are responsible