Prior context influences motor brain areas in an auditory oddball task and prefrontal cortex multitasking modelling

Abstract

In this study, the relationship of orienting of attention, motor control and the Stimulus- (SDN) and Goal-Driven Networks (GDN) was explored through an innovative method for fMRI analysis considering all voxels in four experimental conditions: standard target (Goal; G), novel (N), neutral (Z) and noisy target (NG). First, average reaction times (RTs) for each condition were calculated. In the second-level analysis, 'distracted' participants, as indicated by slower RTs, evoked brain activations and differences in both hemispheres' neural networks for selective attention, while the participants, as a whole, demonstrated mainly left cortical and subcortical activations. A context analysis was run in the behaviourally distracted participant group contrasting the trials immediately prior to the G trials, namely one of the Z, N or NG conditions, i.e. Z.G, N.G, NG.G. Results showed different prefrontal activations dependent on prior context in the auditory modality, recruiting between 1 to 10 prefrontal areas. The higher the motor response and influence of the previous novel stimulus, the more prefrontal areas were engaged, which extends the findings of hierarchical studies of prefrontal control of attention and better explains how auditory processing interferes with movement. Also, the current study addressed how subcortical loops and models of previous motor response affected the signal processing of the novel stimulus, when this was presented laterally or simultaneously with the target. This multitasking model could enhance our understanding on how an auditory stimulus is affecting motor responses in a way that is self-induced, by taking into account prior context, as demonstrated in the standard condition and as supported by Pulvinar activations complementing visual findings. Moreover, current BCI works address some multimodal stimulus-driven systems.

Keywords: Attention; Cognitive modelling; Cue–target onset asynchrony (CTOA); Electroencephalography (EEG); Event-related potential (ERP); Executive function; Functional magnetic resonance imaging (fMRI); Motor networks; Multitask applications; Orienting of attention; Prefrontal cortex (PFC); Running average reaction times.

Fig. 1

Preprocessing and analysis diagram used for the auditory oddball task in the simultaneous EEG and fMRI recording

Fig. 2

Running average of RT for conditions G (coloured in black) and NG (coloured in gray) in the 12 participants. Solid lines in the upper plots are the means at every condition (black for standard target condition and gray for noisy target). In the bottom plots the difference of the RTs between G and NG is shown

Fig. 3

Cross-sectional images with the blue cross bars point to the maximum F value in brain regions for the contrast between sequences N.G and G.G as conditions on the top and sequences N.G and NG.G as conditions on the bottom

Fig. 4

Comparison of the positive and negative difference of the brain areas for the contrast Z.G vs. G.G, showing an interaction between Filtering and Reorienting mode of attention

Fig. 5

Positive differences of the brain regions for the contrast N.G vs. G.G, showing an interaction between Filtering and Reorienting mode of attention. Several attention areas on the Right hemisphere were with relatively greater activations to the NG condition

Fig. 6

Modelling of number of prefrontal areas activated by several generators, where motor response modulated brain areas activated