Biomedical subjects

Laurence Carbonnell

Publications and source records attributed to Laurence Carbonnell.

4 recordsLinked to original sources

PubMed2006

Does the error negativity reflect the degree of response conflict?

The recruitment of performance control was recently explained in terms of the detection of response conflict. One recent hypothesis claims that the degree of response conflict is reflected in an electroencephalographical component, the Error Negativity (Ne). Indeed, in the framework of simulations, variations of the Ne fitted well with variations of response conflict. The objective of the present study was to test the conflict hypothesis of the Ne in a real experimental situation. The subjects performed an arrowhead flanker task with two alternative responses. The degree of conflict was measured by the degree of the co-activation of the forces exerted by the two alternative effectors. Trials with co-activations (i.e., an incorrect response activation followed by a correct one) were selected. These trials were divided into two categories, namely trials with suprathreshold error force (full errors) and subthreshold error force (partial errors). The results showed that although the degree of conflict was larger for full than for partial errors, the Ne was not different for the two categories. Our study does not support the hypothesis that the Ne amplitude reflects the degree of conflict.

Adolescent↗

PubMed2006

A reasoning bias revealed by electrodermal activity.

The sufficiency of behavioral data supporting reasoning biases was challenged. Our objective was to test if physiological data could significantly support reasoning biases. Experiment 1: When performing a rule discovery task with feedback, participants systematically gave the same response. This was not compatible with norms referring to a formal logic system, but was insufficient to conclude there was a reasoning bias. Only the knowledge of participants' expectations of feedback would merit this conclusion. Experiment 2: Participants' expectations were indexed by electrodermal activity. The results showed that when participants displayed the behavioral bias, they considered their responses to be correct and hence committed an error of logic. However, this error of logic did not prevent them from solving the task. This argues for a theory according to which human reasoning uses more economical strategies than the simple application of formal logical rules.

Adult↗

PubMed2004

The modulation of the Ne-like wave on correct responses foreshadows errors.

In reaction time (RT) tasks, event-related potentials (ERPs) reveal a response-locked negative wave when subjects commit errors. This wave, termed "error negativity" (Ne) or "error-related negativity" (ERN), is thought to index response-monitoring processes. With conventional monopolar recordings, this negativity is hardly seen on correct responses, likely overlapped by a large positive wave. Indeed, after Laplacian transformation (a spatial high-pass filter), a small Ne-like wave is unmasked. Recently, it has been shown that the positivity on monopolar recordings was larger for correct responses preceding an error than for correct responses preceding a correct trial. After Laplacian transformation, it appears that this effect is due, at least in part, to a decrease of the Ne-like wave on correct responses preceding an error. This result indicates that, as the Ne on errors, the Ne-like wave on correct responses is sensitive to performance and hence is likely related to response-monitoring processes.

Adult↗

PubMed2004

On-line executive control: an electromyographic study.

In a choice reaction time (RT) task, electromyographic (EMG) recordings allowed us to fractionate RT into two subcomponents, namely premotor time and motor time. This has been done for correct trials and errors. The analysis of the EMG burst and motor time (between EMG onset and overt response) showed that the EMG burst amplitude was reduced and the motor time was longer for errors than for correct responses. In the same way as posterror slowing on the RT was interpreted as revealing between-trials changes in executive control, the present data provide direct evidence for an on-line, within-trial, executive control.

Adult↗