Effects of multisensory stimuli on inhibitory control in adolescent ADHD: It is the content of information that matters

Abstract

Even though deficits in inhibitory control and conflict monitoring are well-known in ADHD, factors that further modulate these functions remain to be elucidated. One factor that may be of considerable importance is how inhibitory control is modulated by multisensory information processing. We examined the influence of concurrent auditory conflicting or redundant information on visually triggered response inhibition processes in adolescent ADHD patients and healthy controls. We combined high-density event-related potential (ERP) recordings with source localization to delineate the functional neuroanatomical basis of the involved neurophysiological processes. In comparison to controls, response inhibition (RI) processes in ADHD were compromised in conflicting conditions, but showed no differences to controls when redundant or no concurrent auditory information was presented. These effects were reflected by modulations at the response selection stage (P3 ERP) in the medial frontal gyrus (BA32), but not at the attentional selection (P1, N1 ERPs) or resource allocation level (P2 ERP). Conflicting information during RI exerts its influences in adolescent ADHD via response selection mechanisms, but not via attentional selection. It is not the mere presence of concurrent information, but the presence of conflicting information during RI that may destabilize goal shielding processes in medial frontal cortical regions, by means of increasing the automaticity of response tendencies. The occurring RI deficits might relate to the increased impulsivity in adolescent ADHD and a corresponding vulnerability to react to an increased automaticity of pre-potent response tendencies. ADHD patients show a bias to a specific content of information which can modulate inhibitory control.

Keywords: ADHD; Action control; Automaticity of response tendencies; Goal-shielding processes; Response inhibition.

Fig. 1

FA rates (with corresponding SEMs) for both groups in the NoGo_without, NoGo_compatible and NoGo_incompatible condition. Controls are depicted in black, individuals with ADHD in grey. The grey and black shaded bars depict the FA group differences in each NoGo condition.

Fig. 2

Event-related potentials on Go and NoGo trials averaged across electrode P7 and P8 (only for creation of this figure). Time point zero denotes the time point of Go, or NoGo stimulus presentation. The different lines show the NoGo_without condition (blue lines), NoGo_compatible condition (orange lines) and the NoGo_incompatible condition (red lines) and the Go condition (green). The scalp topography plots show the distribution of the scalp electrical potential for the P1 (upper row), and N1 (lower row) on Go and NoGo trials. Figure part A shows the ERPs and scalp topographies for controls. Figure part B shows the ERPs and scalp topographies for ADHDs.

Fig. 3

Event-related potentials on Go and NoGo trials at electrode Cz. Time point zero denotes the time point of the Go, or NoGo stimulus presentation. The different lines show the NoGo_without condition (blue lines), NoGo_compatible condition (orange lines), the NoGo_incompatible condition (red lines) and the Go condition (green). The scalp topography plots show the distribution of the scalp electrical potential for the P2 (upper row), N2 (middle row) and P3 (lower row) on Go and NoGo trials. Figure part A shows the ERPs and scalp topographies for controls. Figure part B shows the ERPs and scalp topographies for ADHSs. Additionally the sLORETA source of the group differences in the NoGo_incompatible condition is displayed in figure part B (corrected for multiple comparison, p < .01). The sLORETA colour scale denotes critical t-values. Additionally, a boxplot showing P3 differences between both groups is shown.