Generalized lapse of responding in trait impulsivity indicated by ERPs: The role of energetic factors in inhibitory control.
Impaired inhibitory control is one of the still debated underlying mechanisms of trait impulsivity. The Cognitive Energetic Model accounts for the role of energetic factors mediating task performance. The aim of the present study was to compare inhibitory control functions of adults with high and low impulsivity by using a modified Eriksen flanker task. Adults were classified as impulsive (n=15) and control (n=15) participants based on the Barratt Impulsiveness Scale. Flanker trials had three levels of required effort manipulated by visual degradation. We analyzed RT, accuracy, and ERPs time-locked to the flanker stimuli. Reaction time of impulsive participants was generally slower than that of controls', but accuracy was similar across groups. N2c showed that monitoring of response conflict was modulated by task requirements independent of impulsivity. The P3 latency was delayed in the impulsive group indicating slower stimulus evaluation. The P3 amplitude was reduced in the control group for moderately degraded incongruent trials suggesting that the attentional resources were employed less. The Lateralized Readiness Potential (LRP) peaked later in the impulsive group irrespective of experimental effects. The amplitude of the positive-going LRP recorded in the incongruent condition was comparable across groups, but the latency was delayed partly supporting a stronger susceptibility to stimulus interference of impulsive participants. Their delayed incongruent negative-going LRP reflected a weaker response inhibition and a slower correct response organization. In conclusion, impaired inhibitory functions in impulsivity could not be unequivocally demonstrated, but we found a generalized lapse of motor activation.
Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary; Doctoral School of Psychology, Eötvös Loránd University, Izabella utca 46, H-1064 Budapest, Hungary; Institute of Psychology, Eötvös Loránd University, Izabella utca 46, H-1064 Budapest, Hungary. Electronic address: kobor.andrea@ttk.mta.hu.
Andrea
A
Kóbor
Institute of Psychology, Eötvös Loránd University, Izabella utca 46, H-1064 Budapest, Hungary. Electronic address: takacs.adam@ppk.elte.hu.
Adám
A
Takács
Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary; Institute of Psychology, Eötvös Loránd University, Izabella utca 46, H-1064 Budapest, Hungary. Electronic address: honbolygo.ferenc@ttk.mta.hu.
Ferenc
F
Honbolygó
Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary; Institute of Psychology, Eötvös Loránd University, Izabella utca 46, H-1064 Budapest, Hungary. Electronic address: csepe.valeria@ttk.mta.hu.
Valéria
V
Csépe
Cognitive Energetic Model; ERP; Eriksen flanker task; Impulsivity; Inhibitory control; Lateralized Readiness Potential