Master of Arts
Dr. Eric Buckolz
With identity negative priming (INP) designs, subjects respond on the basis of a target stimulus’ identity and trials are presented in pairs; first the ‘prime’ and then the ‘probe’; with the target and/or to-be-ignored distractor objects appearing on either trial. The latency-based INP phenomenon reflects the fact that probe trial target reactions are significantly slower when this target has just served as the prime distractor object, relative to when it was new. One explanation for the INP phenomenon is that the prime distractor event is inhibited and representations of this are stored so that they are retrieved when the probe trial is delivered and then participates in related processing on this trial. Its participation produces inhibitory after-effects such as the INP effect. The specific question here is what aspect of the prime distractor event is inhibited that causes the INP effect (i.e., locus question); its object (i.e., Object NP), its response (i.e., Response NP) or both?
The task employed here to examine the locus of the INP effect used the numbers 1-8 as inputs that were mapped in pairs onto a single button-press finger response (many:1 mapping), allowing us to (a) repeat both the prime distractor object and its response as the probe target (ignored-repetition), (b) repeat the prime distractor response but not the prime distractor object (distractor-response repeat) and, (c) repeat nothing from the prime trial (control trial) [RT(a) > RT(b) = Object NP; RT(b) > RT(c) = Response NP]. In addition to this manipulation, we used three Response Conflict trial types on the probe trials (conflict distractor, neutral distractor, no probe distractor). This allowed us to test the assertion that an INP would only materialize if the probe contained a conflict distractor (which had an assigned experimental response). Finally, two groups were distinguished on the basis that one had pre-experimental trials to enhance the number-to-finger association strength (Practice Group), the other did not (No Practice Group).
The main findings of note and their implications were as follows: (i) as expected, prime trial distractor events were processed, seemingly to the point of the activation and subsequent inhibition of their related response (i.e., ‘conflict’ [assigned response] but not ‘neutral’ [no assigned response] probe distractors produced significantly elevated reaction times beyond that of the control condition, indicating that this latency elevation was due to the distractor response, likely because it caused a response conflict which took time to resolve), (ii) stored prime distractor response processing was retrieved and participated in ‘related’ probe trial processing (i.e., evidenced in the inhibitory after-effects they produced), such as on ignored-repetition and distractor-response repeat trials. The nature of the probe trial inhibitory after-effects produced by the retrieved prime distractor response was somewhat unexpected, however. Error rates were greater for those trials that required the prime distractor response on the probe trial, relative to the control condition error values. Presumably, this result reflects the execution resistance property of formerly inhibited distractor responses which, essentially, argues against using the correct response. So, we have a purely response-based inhibitory after-effect in identity tasks, one that is in error rate terms (i.e., an error-based INP effect). What was surprising here was that the same execution resistance property of the former prime distractor response, which caused the error rate difference, did not take time to set aside (i.e., override). Hence, the involvement of the prime distractor response did not produce a significant Response NP component in the time domain, and so does not support past work showing the contrary (i.e., latency-based Response NP), and, (iii) when a significant time-based INP effect was seen in the No Practice group, it occurred only when the probe distractor was conflict in nature, supporting Moore’s (1994) assertion that such a context is necessary for INP to manifest itself. The reason for this need remains unsettled.
Shuriye, Ahmed, "Distractor Processing in Identity Negative Priming Tasks" (2015). Electronic Thesis and Dissertation Repository. 3029.