Event-Related Potential Study of P2 and N2 Components on Fast and Slow Responses in the Auditory Condensation Task

Abstract

In tasks involving response choice based on certain stimulus-to-response mappings, at least two stages of information processing may be involved: (1) formation of sensory stimulus object representations leading to stimulus identification, and (2) application of stimulus-to-response mappings (i.e. "task rules") to these representations leading to response selection. Most of the research done in this area involved simple reflex-like stimulus-to-response mappings, thus addressing mostly the perceptual aspect of decision making. Here we used the condensation task, which involves more complex stimulus-to-response mappings. Within each subject, we divided participants' responses into four conditions depending upon performance speed and accuracy: fast correct, fast erroneous, slow correct and slow erroneous responses. We compared event-related potentials between these conditions. We found that P2 amplitude was related to performance accuracy, the effect being evident for fast but not for slow responses. N2 amplitude was increased for slow responsesboth correct and erroneous. We suggest that fast errors result mostly from erroneous sensory representations that immediately become translated into actions in conditions of low motor threshold. On the contrary, slow responses happen in conditions of low executive attention, through reevaluation of sensory representations and invocation of cognitive control process via the mechanisms of response conflict detection.

Magnetoencephalography reveals differences in brain activations for fast and slow responses to simple multiplications

“…Again, a similar methodology was also applied by Novikov et al 30 who performed within-subject EEG analysis with a distinction between fast and slow behavioral responses (based on the individual medians), to investigate the two different mechanisms that underlie response-speed during a sustained attention task. Similar to the above-mentioned strategies, in our study, efficient (i.e., correct and fast) and inefficient (i.e., correct and slow) responses were compared on an individual basis 31 . In our case, for Fast Responses, the brain is likely to follow a practiced, quick, and efficient route to retrieve the correct response, whereas in Slow Responses it is likely that less efficient (and more variable) strategies are utilized 28 .…”

“…To compare response efficiency, we adopted an individual-based approach to classify the problems into two groups. In our case, efficient (i.e., correct and fast, Fast Responses ) and inefficient (i.e., correct and slow, Slow Responses ) responses were compared on an individual basis (for an analogous strategy, see for example 29 – 31 ). This allowed us to compare not fast and slow responders, but fast and slow responses, within the same individual, comparing two activities in which the processing is likely to be very similar, but with different efficient outcomes.…”

Simple Multiplication in the Brain: A MEG Study Comparing Fast and Slow Responses

“…Again, a similar methodology was also applied by Novikov and colleagues 30 who performed within-subject EEG analysis with distinction between fast and slow behavioral responses (based on the individual medians), to investigate the two different mechanisms that underlie response-speed during a sustained attention task. Similar to abovementioned strategies, in our study, e cient (i.e., correct and fast) and ine cient (i.e., correct and slow) responses were compared on an individual basis 31 . In our case, for Fast Responses, the brain is likely to follow a practiced, quick, and e cient route to retrieve the correct response, whereas in Slow Responses it is likely that less e cient (and more variable) strategies are utilized (LeFevre et al, 1996).…”

“…To compare response e ciency, we adopted an individual-based approach to classify the problems into two groups. In our case, e cient (i.e., correct and fast, Fast Responses) and ine cient (i.e., correct and slow, Slow Responses), responses were compared on an individual basis (for an analogous strategy, see for example [29][30][31] ). This allowed us to compare not fast and slow responders, but fast and slow responses, within the same individual, comparing two activities in which the processing is likely to be very similar, but with different e cient outcomes.…”