Functional connectivity of the frontotemporal network in preattentive detection of abstract changes: Perturbs and observes with transcranial magnetic stimulation and event‐related optical signal

Abstract

Current theories of automatic or preattentive change detection suggest a regularity or prediction violation mechanism involving functional connectivity between the inferior frontal cortex (IFC) and the superior temporal cortex (STC). By disrupting the IFC function with transcranial magnetic stimulation (TMS) and recording the later STC mismatch response with event‐related optical signal (EROS), previous study demonstrated a causal IFC‐to‐STC functional connection in detecting a pitch or physical change. However, physical change detection can be achieved by memory comparison of the physical features and may not necessarily involve regularity/rule extraction and prediction. The current study investigated the IFC–STC functional connectivity in detecting rule violation (i.e., an abstract change). Frequent standard tone pairs with a constant relative pitch difference, but varying pitches, were presented to establish a pitch interval rule. This abstract rule was violated by deviants with reduced relative pitch intervals. The EROS STC mismatch response to the deviants was abolished by the TMS applied at the IFC 80 ms after deviance onset, but preserved in the spatial (TMS on vertex), auditory (TMS sound), and temporal (200 ms after deviance onset) control conditions. These results demonstrate the IFC–STC connection in preattentive abstract change detection and support the regularity or prediction violation account.

The critical role of the inferior frontal cortex in establishing a prediction model for generating subsequent mismatch negativity (MMN): A TMS-EEG study

“…Due to the preattentive nature, the detection of deviance could only be reflected by the MMN or the corresponding mismatch brain responses, but not behavioral measures. Our TMS-optical imaging studies [25,26] showed that single pulse TMS on the right IFC 80 ms after deviant onset abolished the STC mismatch response at 150-200 ms, when the deviant was preceded by 4-7 standards. However, the STC mismatch response was preserved when deviant was preceded by a longer standard train [25].…”

“…In the Auditory Control block, the TMS coil was positioned near the right IFC but Stimulation intensity was set at 80% of the resting motor threshold (rMT), which has demonstrated an inhibitory effect on the brain responses in previous studies [40]. Similar to our previous studies [25,26], rMT was determined by using the 5-centimeter rule (see was determined based on previous TMS-EROS [25,26] and EROS studies [15][16][17][18]41]. The exact IFC location for each individual was obtained by first transforming the individual MRI scan from native space to Talairach space to obtain the transformation matrix, then reverse transforming the IFC location from Talairach space back to native space of each participant using the software AFNI [42].…”

“…Each of the first 2 or 5 standards of the train were paired with a real TMS pulse 80 ms after stimuli onset. Previous TMS study [25,26] J o u r n a l P r e -p r o o f found that the mismatch brain response in the STC was abolished when TMS was applied on the right IFC 80 ms after deviant onset. In addition, right IFC mismatch brain responses to deviants were reliably observed at similar latency in previous studies [15,17,18].…”

“…The final location was within 10 mm to the target location. This procedure was successful in titrating the TMS intensity to produce specific TMS effects on IFC [25,26].…”

“…The IFC generator is speculated to involve in establishing, maintaining, and updating the prediction model for deviance detection [18,20,21] under the prediction violation account; J o u r n a l P r e -p r o o f while the STC generator is commonly agreed to serve as a comparator of the prediction and the incoming event in the detection process [12,13,18,22]. The functional connection between the IFC and the STC in deviance detection was demonstrated by combining transcranial magnetic stimulation (TMS) with brain imaging methods (e.g., rTMS-EEG [23,24] and concurrent single pulse TMS-optical brain imaging [25,26]). Due to the preattentive nature, the detection of deviance could only be reflected by the MMN or the corresponding mismatch brain responses, but not behavioral measures.…”