The medial prefrontal cortex: a potential link between self-deception and affect.

The Medial Prefrontal Cortex (MPFC) is crucial for normal social functioning in humans. Because of its involvement in social monitoring, self-awareness, and self-enhancement, the MPFC may be critical to buffering negative affect and establishing a positive self-esteem. For example, we have previously found that disruption of the MPFC leads to more honest responses, which implies that the MPFC may be critically involved in self-deception. We therefore hypothesized that disrupting the MPFC would lead to a decrease in affect. Employing a virtual lesion TMS (Transcranial Magnetic Stimulation) technique, we disrupted the MPFC while participants rated their mood based on two anchor affect terms. During TMS, the participants rated their current emotional mental state. Compared to sham TMS, it was found that mood was reduced immediately following single-pulse MPFC stimulation. The results supported the hypothesis the MPFC mood reduction occurs when the MPFC is disrupted. Because this study replicated the conditions employed in previous self-deception studies, we suggest that the results may indicate that lack of self-enhancement may lead to a decrease in mood. Further studies should examine this possibility.

The Sol Braiding Method for Handling Thick Hair During Transcranial Magnetic Stimulation: An Address for Potential Bias in Brain Stimulation.

Transcranial Magnetic Stimulation (TMS) is a technique that is frequently utilized in neuroscience for both therapeutic and research purposes. TMS offers critical medical services like treating major depression and is vital in almost every research facility. Because TMS relies on scalp placement, hair is thought to affect efficacy because it varies the distance to the target site. Further, it is presumed that the hair textures and length that are predominantly seen in minoritized persons might pose significant challenges to collecting high-quality data. Here, we present preliminary data demonstrating that TMS may be influenced by hair, particularly in historically underrepresented minoritized groups. The Sol braiding approach is introduced here as an easy-to-learn, quick-to-implement technique that reduces variability in TMS. Compared across nine participants, it was found that the Sol method significantly increased motor evoked potential (MEP) strength and consistency (p < 0.05). By removing the physical hair barrier that impedes direct coil-to-scalp contact, the Sol approach enhances TMS delivery. The MEP peak amplitude and the MEP area under the curve (AUC) were shown to increase as a result. While preliminary, these data are an important step in addressing diversity in neuroscience. These procedures are explained for non-braiding experts.

Employing Transcranial Magnetic Stimulation in a Resource Limited Environment to Establish Brain-Behavior Relationships.

Neuroimaging is typically perceived as a resource demanding discipline. While this is the case in certain circumstances, institutions with limited resources have historically contributed significantly to the field of neuroscience, including neuroimaging. In the study of self-deception, we have successfully employed single-pulse TMS to determine the brain correlates of abilities including overclaiming and self-enhancement. Even without the use of neuro-navigation, methods provided here lead to successful outcomes. For example, it was discovered that decreases in self-deceptive responding lead to a decrease in affect. These methods provide data that are reliable and valid, and such methods provide research opportunities otherwise unavailable. Through the use of these methods, the overall knowledge base in the field of neuroscience is expanded, providing research opportunities to students such as those at our institution (Montclair State University is a Hispanic-Serving Institute) who are often denied such research experiences.

Corticospinal Excitability during a Perspective Taking Task as Measured by TMS-Induced Motor Evoked Potentials.

Only by understanding the ability to take a third-person perspective can we begin to elucidate the neural processes responsible for one's inimitable conscious experience. The current study examined differences in hemispheric laterality during a first-person perspective (1PP) and third-person perspective (3PP) taking task, using transcranial magnetic stimulation (TMS). Participants were asked to take either the 1PP or 3PP when identifying the number of spheres in a virtual scene. During this task, single-pulse TMS was delivered to the motor cortex of both the left and right hemispheres of 10 healthy volunteers. Measures of TMS-induced motor-evoked potentials (MEPs) of the contralateral abductor pollicis brevis (APB) were employed as an indicator of lateralized cortical activation. The data suggest that the right hemisphere is more important in discriminating between 1PP and 3PP. These data add a novel method for determining perspective taking and add to the literature supporting the role of the right hemisphere in meta representation.