Colin Holbrook was supported by the U.S. Air Force Office of Scientific Research Award FA9550-115-1-0469.

All methods described in what follows have been approved by the Office of the Human Research Protection Program (OHRPP) of the University of California, Los Angeles.
1. Pre-experiment Steps
<ol>
	<li>During recruitment, prescreen participants to ensure that they have no medical concerns, no history of neurological or psychological disorders, and no other disqualifying conditions for undergoing TMS, such as using a pacemaker, having any metal implants other than dental fillings, suffering a serious medical illness, taking anti-depressant or anti-psychotic medications, having a personal or family history of seizure disorder, or pregnancy.</li>
	<li>When prescreening (e.g., via phone), also ask questions regarding the prospective participant&#39;s political orientation, US citizenship, religiosity, and ethnicity.
	<ol>
		<li>Exclude non-US citizens or individuals who identify as &#39;extremely liberal&#39; from the study to ensure that the participants will have a negative response to criticisms of the US (e.g., from a Latino immigrant, as has similarly been done in prior studies of intergroup bias)12,54,55.</li>
		<li>Exclude those who identify as either &#39;extremely religious&#39; or as &#39;atheist/agnostic&#39; to ensure that participants will introspectively consider their degree of religious belief rather than answer reflexively on the basis of hardened convictions or habitual responses.</li>
		<li>Exclude individuals who self-identify as &#39;Hispanic/Latino&#39; in advance of the study toensure that the participants view the immigrant characters in the group bias measure as out-group members.</li>
	</ol>
	</li>
	<li>Continue recruitment until there are at least 20 participants who satisfy the screening criteria in each cell of the design.</li>
	<li>Obtain written consent after thoroughly explaining the experiment, including what TMS is and how it works, upon arrival of the prospective participants at the laboratory.</li>
</ol>
2. cTBS Procedure
<ol>
	<li>Seat the participant in a comfortable position and fit a grid-marked swim cap to his/her head. Use earplugs if needed to increase the comfort of the subject. Attach two differential parallel-bar EMG-recording electrodes, centered over the belly of the tibialis anterior muscle, after cleaning the skin over the muscle thoroughly. Attach a third, ground electrode to the skin over a bone somewhere else on the hand or arm.</li>
	<li>On the swim cap, measure and mark the center location (Cz) on the subject&#39;s head.
	<ol>
		<li>If using neuronavigation (recommended), launch the neuronavigation software and follow the software&#39;s procedure for localizing the subject&#39;s head. Have the subject rest comfortably and begin recording the EMG electrode output to software that will filter and display the signal.</li>
	</ol>
	</li>
	<li>Perform thresholding on the primary motor cortex. With a double-cone coil (110 mm), place the center of the coil over the motor cortex, held tangential to the scalp surface. Apply single-pulse TMS at 50% of the maximum stimulus output (MSO) and observe whether a motor-evoked potential (MEP) was present in the EMG signal following the stimulation.
	<ol>
		<li>If no MEP is seen following the stimulation, reposition the coil 1 cm away in any direction and try the stimulation again. Wait at least 6&#8211;10 s between stimulations in order for the neurons to completely recover. Continue moving the coil 1 cm at a time, marking on the cap the stimulation sites that result in an MEP of 50 mV or greater.</li>
		<li>If no MEPs are seen after trying many locations, increase the stimulation intensity by 5% at a time, until MEPs are observed.</li>
		<li>Multiple nearby locations on the grid may elicit reliable MEPs. If this is the case, stimulate each of these locations at intensities decreasing by 1% at a time, until only one location remains that elicits reliable MEPs.</li>
	</ol>
	</li>
	<li>To determine the active motor threshold (aMT), have the subject slightly contract the target muscle. Stimulate the located region for 10 repetitions, separated by ~7 s, at decreasing intensities, until a corresponding observable twitch in the hand muscle no longer occurs for 50% of the stimulations (5 out of 10). The threshold is the lowest intensity that elicits 5/10 twitches.
	<ol>
		<li>Navigate the coil to the specified location on the cap corresponding to the brain region of interest. If the double-cone coil to be used has a directionality of current flow, and if the target region is lateralized, orient the coil laterally so that the current flow is directed toward the hemisphere to be stimulated (e.g., a rightward current flow for a right hemisphere target)56,57.
		<ol>
			<li>If using neuronavigation, locate the coordinates for the region of interest (pMFC) at Montreal Neurological Institute (MNI) coordinates [8, 16, 52] and mark this point on the system. Use the guiding software to target the region with the coil.</li>
			<li>If neuronavigation is unavailable due to logistical or financial constraints (as was the case in the example experiment), determine the location of the pMFC for each subject&#39;s head using the international 10&#8211;20 system58. Place the coil 3.75 cm anterior to the motor cortex.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>Apply cTBS as follows: three pulses at 50 Hz repeated at 200 ms intervals for 40 s, totaling at 600 pulses.</li>
	<li>If the participant is in the sham group, apply cTBS at only 10% of the maximal stimulation output.</li>
</ol>
3. Survey Tasks
<ol>
	<li>Seat participants alone, in a private setting, at a desktop computer to perform the computer-mediated survey tasks.</li>
	<li>Remind participants that their responses will be anonymous, confidential, and inaccessible to the research assistant, particularly to the extent that the target judgments (e.g., group bias and religious belief) are likely to raise self-presentation concerns (e.g., to appear patriotic, or not to appear prejudiced) which might obscure the effect of the cTBS manipulation.</li>
	<li>Present participants with filler tasks for 10 min before starting the main task, as the maximal effect of cTBS begins 5&#8211;10 min after the stimulation53, and in order to minimize demand effects.
	<ol>
		<li>Administer the Multiple Source Interference Task59 (MSIT) (or a comparable distracter), as this task is highly cognitively demanding and requires approximately 10 min.</li>
		<li>Next, present a set of ostensibly unrelated survey tasks, beginning with two further filler distracters: challenge the participants to estimate the number of colors present in images of jellybeans and seashells that have been converted to greyscale.</li>
	</ol>
	</li>
	<li>Instantiate the threat context. If the ideological shifts of theoretical interest pertain to responses to death (as in this example study), ask participants to write two brief passages on the subject of their mortality60 by saying: (a) &#34;Please briefly describe the emotions that the thought of your own death arouses in you&#34; and (b) &#34;Please jot down, as specifically as you can, what you think will happen to your body as you physically die and once you are physically dead.&#34;</li>
	<li>Following the threat-induction task, administer the Positive and Negative Affect Schedule - Expanded Form (PANAS-X)61 to allow self-reporting of potential effects of the cTBS intervention on emotional responses to the threat induction, as well as to distract the participants from the death prime encountered earlier in the protocol55.</li>
	<li>Next, administer the relevant ideological judgment tasks. 
	NOTE: In the example given here, group bias and religious conviction were assessed. If more than two measures are employed, present them in a counterbalanced order.
	<ol>
		<li>To assess group bias with regard to ideological conflict, present participants with two essays ostensibly written by immigrants to the United States from Latin America (counterbalanced order) and ask participants to evaluate the authors and their arguments62. Note that there are intentional grammatical errors included in both essays which should not be corrected.
		<ol>
			<li>Present the &#34;Pro-U.S.&#34; essay: 
			The first thing that hit me when I came to this country, was the incredible freedom people had. Freedom to go to school, freedom to work any job you want. In this country people can go to school and train for the job they want. Here anyone who works hard can make their own success. In my country most people live in poverty with no chance of escape. In this country people have more opportunity for success than any other and success does not depend on the group belong to. While there are problems in any country, America truly is a great nation and I don&#39;t regret my decision to come here at all.&#34;</li>
			<li>Present the&#34;Anti-U.S.&#34; essay: 
			When I first came to this country I believed it was the &#34;land of opportunity&#34; but I soon realized this was only true for the rich. The system here is set up for the rich against the poor. All people care about here is money and trying to have more than other people. This no sympathy for people. It&#39;s all one group putting down others and nobody cares about the foreigners. The people only let foreigners have jobs like pick fruit or wash dishes because no American would do it. Americans are spoiled and lazy and want everything handed to them. America is a cold country that is unsensitive to needs and problems of foreigners. It thinks it&#39;s a great country but its not.&#34;</li>
			<li>After presenting each essay, ask participants to rate their agreement with six statements using an 8-point Likert scale (1= &#39;Strongly Disagree&#39;; 8 = &#39;Strongly Agree&#39;): (i) &#34;I like the person who wrote this&#34;, (ii) &#34;I think this person is intelligent&#34;, (iii) &#34;This is the kind of person I would like to work with&#34;, (iv) &#34;I think this person is honest&#34;, (v) &#34;I agree with this person&#39;s views&#34;, and (vi) &#34;I think this person&#39;s opinions of America are true.&#34;</li>
			<li>Assess these responses for reliability and, if sufficiently reliable, average them. To explore potentially distinct effects of cTBS on personal affiliation (items I - iv) versus ideological agreement (items v and vi), average them to create submeasures (see Figure 1).</li>
		</ol>
		</li>
		<li>Measure religious conviction according to a modified version of the Supernatural Belief Scale63 (SBS) in which two distinct subscales tap positive and negative aspects of Western religious belief, mirroring the positive and negative valence of the two essays in the group bias measure.
		<ol>
			<li>Present the SBS items in random order (positive scale: i - iii; negative scale: iv - vi), rated according to the same scale employed in the group bias measure: (i) &#34;There exists an all-powerful, all-knowing, loving God&#34;; (ii) &#34;There exist good personal spiritual beings, whom we might call angels&#34;; (iii) &#34;Some people will go to heaven when they die&#34;; (iv) &#34;There exists an evil personal spiritual being, whom we might call the Devil&#34;; (v) &#34;There exist evil, personal spiritual beings, whom we might call demons&#34;, and (vi) &#34;Some people will go to hell when they die.&#34;</li>
			<li>Assess the responses for each subscale for reliability and average them if sufficiently reliable.</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>

The authors have nothing to disclose.

Downregulating the pMFC via cTBS significantly reduced bias toward an out-group member critical of the US and avowed religious belief in the aftermath of a vivid reminder of death, consistent with both the hypothesized role of the pMFC in ideological threat-reactions and with the promise of TMS as a method for experimentally manipulating ideological cognition. While encouraging and consonant with a substantive background literature, the results of any single study should be considered to be highly preliminary. In addition, the cTBS methods employed here should be understood as subject to significant improvement.
Although TMS has a relatively good spatial accuracy (a few mm), there are limitations that impede accurate focal stimulation, such as between-subject brain variability. The site of stimulation is selected based on the average coordinates of a particular brain region, and the actual location of any region of interest will vary from individual to individual. Accuracy can be improved by using individual subjects&#39; magnetic resonance imaging (MRI) images, as these images can be used in concert with a neuronavigation system to target particular regions on the imaged brain as a best practice. Unfortunately, because MRI scans are often prohibitively costly, most TMS studies (including the example given in this paper) have not had access to neuronavigation.
The differential recruitment of cortical neurons may also contribute to a variability in the effects of cTBS, resulting in potentially opposite effects of both cTBS and iTBS in some individuals. Hamada and colleagues64 report finding no overall difference in MEP modulation among 52 participants receiving cTBS versus iTBS to the primary motor cortex. In their study, some participants exhibited a facilitatory response to cTBS and an inhibitory response to iTBS, while others displayed the reverse pattern, and still others showed uniformly inhibitory or excitatory responses to either form of stimulation. Although many other studies have been able to induce the expected response in their overall sample, Hamada and colleagues&#39; results militate for assessing individual differences in responses to cTBS (or iTBS if applicable) in future experimental designs; Hamada et al. provide a detailed description of how MEP latencies may be used to predict a cTBS/iTBS response within subjects64.
Achieving the correct coil orientation and positioning for each subject is another effective means of reducing potential variability in the effects of TBS. When available, stereotaxic neuronavigation software that guides the positioning and orientation can help to ensure accurate stimulation. In any event, running a large number of subjects in each experimental condition can also help to mitigate potential noise related to differential responsiveness to TBS.
An additional consideration when performing cTBS is how to implement an appropriate control condition. As was done here, cTBS may be contrasted with a sham condition (i.e., pointing the coil away to avoid actual brain stimulation, or lowering the intensity far below threshold). However, as it is conceivable that the cTBS of any region might induce changes in behavior, a common and arguably best practice is to introduce a condition wherein stimulation is delivered to a region thought to be unrelated to the task.
Stimulation of any one region can lead to a spreading activation to regions that are functionally downstream from or proximal to the area of interest, such that causal interpretations of the functional contribution of individual regions must be undertaken with great caution. Relatedly, augmenting cTBS of the pMFC with neuroimaging would importantly clarify the relative effect of the manipulation on the dmPFC versus dACC subcomponents of the pMFC, in addition to the potential collateral enervation of connected regions. At present, it remains unclear whether the observed effects are owed to downregulation of the dACC, dmPFC, or both. In addition to conventional neuroimaging, connectomic analyses might shed light on how pMFC mechanisms articulate with other regions throughout the brain to modulate ideological modes of cognition.
While cTBS of the pMFC to influence high-level social and ideological judgments remains a relatively new and little-tested method, it has been shown to reduce social conformity48 and monetary sharing39, in addition to the present reductions in group bias and religious belief1. While these findings are encouraging, the extent to which cTBS of the pMFC will influence such high-level judgments remains unclear, as is the replicability of previous effects. In the study highlighted here, prospective participants were carefully prescreened to exclude &#39;hardliners&#39; with respect to both political orientation (strong liberals or conservatives) and religiosity (committed believers or atheists), leaving a sample of relatively moderate individuals. This effort was made to avoid individuals with hardened attitudes, who may produce reflexive responses via pathways distinct from those involved in the process of actively considering ideological positions. While sensible, these screening criteria may have inadvertently introduced a sample bias of some sort related to factors which deter &#39;middle-of-the-road&#39; individuals from holding firm positions. Where resources allow for larger and more diverse samples, future researchers should include a broad spectrum of political and religious orientations in order to assess potential moderating effects of such individual differences.
In the present design, all participants were reminded of death to establish a context in which participants might be expected to draw on positive religious beliefs as an ideological solution. Although the findings were consistent with this interpretation, as well as with prior work linking religiosity with confidence in the face of physical danger65,66,67,68, exposing all participants to a death prime constitutes a serious limitation, as the data cannot reveal whether downregulation of the pMFC would produce comparable effects at baseline, in the absence of a recent threat cue. Further, it is not possible to determine whether the reduction in out-group bias toward the critical immigrant observed following cTBS of the pMFC reflects a muting in the impact of the death prime, a muting in the impact of the ideological conflict posed by the criticism of the US, or an interaction between the two. Thus, future work should incorporate a non-threat control condition to test whether, regardless of the presence of a background threat such as a reminder of death, downregulation of the pMFC reduces group bias or religious belief.
The present threat-induction was chosen because of the link between the prospect of dying and reassuring concepts of the afterlife, and secondarily because mortality-salience induction has been shown to heighten intergroup prejudice69. Alternate non-death threat inductions related to challenges in domains pertinent to other social judgments might be comparably employed. Importantly, non-death threat primes have been demonstrated to reliably modulate social judgments14,55,69.
Finally, one of the most challenging aspects of this work is that it requires expertise not only in TMS techniques but also in manipulating and measuring relatively abstract constructs such as ideological adherence. Thus, wherever possible, research teams should include investigators with relevant experience in disciplines such as social psychology, political psychology, or anthropology, as well as neuroscience.

This paper presents a recently developed method for experimentally neuromodulating ideological threat-reactions, with a particular focus on nationalistic bias and religiosity1. Importantly, however, the procedure presented in what follows should be taken as an illustrative token of a promising general approach to the study of the neural substrate of high-level social and ideological cognition (e.g., with regard to normative judgments, political attitudes) using transcranial magnetic stimulation (TMS). To theoretically situate this &#39;proof-of-concept&#39; example, prior work on links between threat-detection and ideological investment, including plausible neural correlates of these effects, is briefly reviewed.
Threat and Ethnocentrism
People live in, and sometimes die for, social groups2. By assorting into coalitions, individuals benefit from shared access to both knowledge and material resources. Because sharing valued material or informational resources renders people vulnerable, individuals are incentivized to calculate whether others are likely to reciprocate or abuse their generosity3. Categorizing another person as sharing an investment in an in-group is thought to privilege coordination between fellow in-group members by enhancing mutual care and trust. This group-favoring ethnocentrism can also lead to a negative valuation of those perceived to be aligned with out-groups-and hence to be unreliable if not overtly antagonistic and, therefore, undeserving of in-group resources4,5. Under contexts of conflict, group prejudice appears not only to discourage cooperation but to motivate aggression against individuals perceived to belong to or sympathize with enemy coalitions6. If, over deep time, in-group favoritism advances reproductive fitness7,8, then the mind may have been shaped by selection to support ethnocentrism9,10, particularly under contexts of threat11,12. Consistent with this functional interpretation of ethnocentrism, the extent to which individuals express commitment to group ideologies has been observed to increase following primes of threat13,14,15. Although social scientists have studied the influence of threats on ideological commitment for decades, only recently has attention turned to the brain mechanisms at work16,17,18,19,20. In the present protocol, a brain region previously associated with low-level problem solving (e.g., updating motor responses to obtain a reward) is demonstrated to contribute to facultative shifts in ideological beliefs.
Threat, Ideological Commitment, and the Posterior Medial Frontal Cortex
The pMFC includes the dorsal anterior cingulate cortex (dACC) and the dorsomedial prefrontal area anterior to the supplementary motor cortex (dmPFC). The pMFC has been implicated in an array of reactions to negative stimuli21,22,23. The pMFC contributes to the detection of discrepancies between current and preferred conditions, as well as to subsequent decision-making adjustment of behavior to reduce such discrepancies24,25,26. For example, the dACC has been implicated in relatively low-level cognitive control functions such as those measured in the Stroop, Flanker, divided attention, or Go/No-Go tasks25. Similarly, at a higher level of abstraction, the dACC component of the pMFC is hypothesized to evoke intensified expressions of ideological commitment to moral or cultural values following exposure to threats (e.g., reminders of uncertainty or death)17,18. Cues of the concept of death have been found to similarly trigger activity in the dmPFC27,28 and to intensify ideological expressions (e.g., national identification, punishment of norm-violators)14. Cues of social isolation have likewise been observed to heighten ethnocentrism12 and to activate the dACC29.
The dmPFC component of the pMFC is a particularly plausible inhibitor of prosociality toward out-group members, as the dmPFC is considered important to modulating the treatment of self versus other during social decision-making30,31. A growing literature suggests that human prosocial inclinations-most pronounced toward fellow in-group members, all else being equal-may partially derive from a tendency for feelings and behaviors to activate similar neural systems, whether originating in the self or in another32. The extent of this self-other neural resonance has been found to predict prosocial behavior33,34,35. Consistent with the role of coalitional bias in moderating prosociality, neural resonance and related prosocial behaviors are influenced by factors such as group identity36,32. The modulation of prosociality contingent on group identification may owe to mechanisms of inhibitory prefrontal cognitive control involving the dmPFC, as the dmPFC is important for the tonic control of spontaneous imitation37,30, as well as for shifting between the perspectives of self and other38. Most compellingly, downregulating the dmPFC causes greater financial sharing behavior39, directly implicating the dmPFC as inhibiting prosociality, plausibly including the suppression of prosociality on the basis of out-group affiliation. These relatively high-level social functions of the dmPFC may be understood as manifestations of a larger role of the dmPFC in various cognitive control functions40. For example, experimentally upregulating the dmPFC was recently shown to enhance impulse control in an asocial delay-discounting paradigm in which participants who postpone immediate reward receive greater future reward41.
The pMFC complex appears responsive to cues of the presence of various sorts of social discrepancies, and pMFC activity predicts behavioral shifts designed to reduce said discrepancies42. For instance, pMFC activity correlates with preference changes in a manner that appears to reduce cognitive dissonance43,44,45 or to heighten social conformity following evidence that a person&#39;s opinions deviate from the group consensus46,47. In a demonstration of the causal role of the pMFC in enabling such dynamics, the experimental downregulation of pMFC activity via TMS has been shown to decrease social conformity despite cues of disagreement with the group48. In sum, upon detection of relatively low-level problems such as receiving a negative outcome in a motor task24, or relatively high-level problems such as a deviation between a person&#39;s stated views and those of his/her peers, the pMFC appears involved in the activation of networks that coordinate problem-relevant responses23,47,49.
Considered together, the overall pattern of results implicates the pMFC as part of neurobiological architecture evolved to manage challenges spanning various low-level and high-level domains. Accordingly, when participants are presented with an out-group member&#39;s critique of their group, the pMFC would hypothetically be involved in detecting this conflict and with coordinating a typical response: derogation of that out-group critic and their ideas. By the same logic, the pMFC is predicted to help enable individuals confronted with their own mortality to amplify their belief in a pleasant afterlife. If so, then participants for whom the pMFC complex has been downregulated may be expected to evince less derogation of critical out-group members and less religious belief following reminders of the inevitability of death.
Downregulating Targeted Cortical Areas Via Continuous Theta Burst Stimulation
Theta burst stimulation (TBS) is a form of patterned TMS. TMS stimulates the brain non-invasively by producing a rapidly varying magnetic field over the stimulated subject&#39;s scalp. This rapidly varying magnetic field induces electric currents in the brain, which in turn lead brain cells to fire50,51,52. In this manner, the manipulation of targeted brain regions via TMS allows research to move past the correlational discoveries of traditional brain mapping methods employing neuroimaging. By stimulating a given brain region and, thereby, decreasing or increasing its activity, causal inferences about the relevance of that region on a variety of behavioral tasks may be inferred.
TBS protocols have been modeled from repetitive electrical stimulation protocols that induced long-term potentiation (LTP) or long-term depression (LTD) in animal studies53. Continuous theta burst stimulation (cTBS), which consists of 50 Hz triplets of pulses delivered at 5 Hz for 40 s, for a total of 600 pulses, has an effect similar to LTD, reducing the activity in the stimulated area for an estimated period of at least 1 hour. Intermittent TBS (iTBS) consists of the same pattern of bursts at the same frequency of cTBS. However, in iTBS, the subject is stimulated for 2 s at a time, which is repeated every 10 s for 190 s (totaling 600 pulses, as in cTBS). iTBS has an effect similar to LTP, enhancing the activity in the stimulated area for a period of time comparable to cTBS. Whereas the cTBS method highlighted here can reduce ideological threat-responses, theoretically, iTBS may heighten ideological threat-responses.
The protocol that follows details methods recently used to experimentally downregulate group bias and religious belief with cTBS1, in the hope that researchers interested in alternate modes of ideological threat-response might replicate these effects and/or modify this general approach for their own purposes (e.g., substituting alternate threat primes and/or judgment outcomes, or by adding a control stimulation site).

<table border="0" cellpadding="0" cellspacing="0" style="width:752px;" width="750">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:379px;">Isopropyl alcohol</td>
			<td style="width:139px;"></td>
			<td style="width:144px;"></td>
			<td style="width:91px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ear plugs</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Adult swim cap</td>
			<td>Sprint Aquatics</td>
			<td>304</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MobiMini 2-channel recording system</td>
			<td>TMSi</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">EMG electrodes</td>
			<td>TMSi</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Covidien Kendall disposable surface electrodes (24 mm)</td>
			<td>Bio-medical</td>
			<td>H124SG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Magstim Rapid2 TMS device</td>
			<td>Magstim</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">D70 figure-of-eight coil</td>
			<td>Magstim</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Visor2 Neuronavigation software</td>
			<td>ANT Neuro</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

continuous theta burst stimulation of the posterior medial frontal cortex to experimentally reduce ideological threat responses

Decades of behavioral science research have documented functional shifts in attitudes and ideological adherence in response to various challenges, but little work to date has illuminated the neural mechanisms underlying these dynamics. This paper describes how continuous theta burst transcranial magnetic stimulation may be employed to experimentally assess the causal contribution of cortical regions to threat-related ideological shifts. In the example protocol provided here, participants are exposed to a threat prime-an explicit reminder of their own inevitable death and bodily decomposition-following a downregulation of the posterior medial frontal cortex (pMFC) or a sham stimulation. Next, disguised within a series of distracter tasks, participants' relative degree of ideological adherence is assessed-in the present example, with regard to coalitional prejudice and religious belief. Participants for whom the pMFC has been downregulated exhibit less coalitionally biased responses to an immigrant critical of the participants' national in-group, and less conviction in positive afterlife beliefs (i.e., God, angels, and heaven), despite having recently been reminded of death. These results complement prior findings that continuous theta burst stimulation of the pMFC influences social conformity and sharing and illustrate the feasibility of investigating the neural basis of high-level social cognitive shifts using transcranial magnetic stimulation.

In the example study, the final sample consisted of 38 participants (58% female, Mage = 20.9 years, SD = 2.67). About 36.8% of the participants identified as White, 36.8% as East Asian, 13.2% as South Asian, 7.9% as Middle Eastern, and 5.3% as Other. As intended, the sample was politically moderate (M = 4.68, SD = 1.51; 1 = &#34;Extremely Liberal&#34;; 5 = &#34;Moderate&#34;; 9 = &#34;Extremely Conservative&#34;).
Preliminary ANOVA tests detected a significant effect of the order of essay presentation on ratings of the &#34;anti-US&#34; immigrant, F(1, 36) = 5.30, p = 0.027, &#951;2 p = 0.13, 95% confidence interval (CI) [-2.07, -.13], with no order effect observed for ratings of the &#34;pro-US&#34; immigrant, p = 0.74. Accordingly, the essay order was included as a covariate in subsequent analyses. (Follow-up tests confirmed that controlling for order does not alter the overall pattern of results.) Such order effects may occur using this measure of group bias and should be routinely checked for as potential sources of noise.
As predicted, cTBS of the pMFC increased positive evaluations of the critical immigrant author, who was rated 28.5% more positively in the TMS condition (M = 4.10, SD = 1.66) than in the control condition (M = 2.93, SD = 1.22), F(1, 35) = 7.01, p = 0.012, &#951;2&#160;p = 0.17, 95% CI [-2.06, -0.27]. Also consistent with the hypothesis that the pMFC reacts to ideological conflict, ratings of the pro-US author (who posed no ideological threat) were an average of 8.2% higher in the cTBS condition (M = 5.90, SD = .87) than in the sham condition (M = 5.42, SD = 1.17), a difference that was not statistically significant, F(1, 36) = 2.09, p = 0.157, &#951;2&#160;p = 0.06, 95% CI [-1.16, 0.20]. Remarkably, exploratory tests revealed that the effects of cTBS were equivalent with respect to both the ratings of the immigrants&#39; personal qualities and the endorsement of their harshly critical arguments, attesting to an effect of the cTBS manipulation on the intensity of the participants&#39; ideological investment in nationalistic values, rather than an effect limited to interpersonal amity (see Figure 1). This finding suggests that applications of this cTBS method addressing forms of ideological adherence relatively unrelated to social affiliation may be attenuated.
Also consistent with predictions, participants who received cTBS reported an average of 32.8% less positive religious conviction (M = 3.05, SD = 1.92) relative to the sham participants (M = 4.54, SD = 2.26), F(1, 36) = 4.80, p = 0.035, &#951;2 p = 0.12, 95% CI [0.11, 2.87]. Participants in the cTBS condition also reported a less negative religious conviction (M = 2.84, SD = 1.89) relative to the sham participants (M = 3.98, SD = 2.50), but this difference did not reach statistical significance, F(1, 36) = 2.52, p = 0.122, &#951;2 p = 0.07, 95% CI [0.32, 2.60]. This result underscores the apparent relevance of the pMFC to recruiting ideological stances (e.g., positive religious beliefs) pertinent to particular problems (e.g., mortality), rather than to ideological adherence in general, as heaven presents a better solution than hell to the problem of death.
There were no apparent effects of condition on any of the 11 PANAS-X affect subscales (ps 0.09&#8211;0.92). Participants in both conditions reported moderately positive affect (cTBS: M = 2.44, SD = 0.61; Sham: M = 2.37, SD = 0.75) and low levels of negative affect (cTBS: M = 1.22, SD = 0.27; Sham: M = 1.43, SD = 0.51). The null effects of cTBS on self-reported emotion suggest that the findings with regard to group bias or religiosity were not driven by changes in emotional reactivity to the reminder of death.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/58204/58204fig1.jpg" /> 
Figure 1:&#160;Effects of cTBS on US citizens&#39; endorsement of the personal appeal and arguments of pro-US and anti-US immigrants. <a href="https://jove.unicartagenaproxy.elogim.com/files/ftp_upload/58204/58204fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Continuous Theta Burst Stimulation of the Posterior Medial Frontal Cortex to Experimentally Reduce Ideological Threat Responses at JoVE.com

Continuous Theta Burst Stimulation of the Posterior Medial Frontal Cortex to Experimentally Reduce Ideological Threat Responses

Threats reliably evoke shifts in high-level ideological investment, but little work to date has explored the neural mechanisms underlying these dynamics. This paper describes how continuous theta burst transcranial magnetic stimulation may be employed to test the contribution of the posterior medial frontal cortex (and/or other regions) to threat-related ideological shifts.

Decades of behavioral science research have documented functional shifts in attitudes and ideological adherence in response to various challenges, but ...

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11.5K Views.  University of California, Merced. Threats reliably evoke shifts in high-level ideological investment, but little work to date has explored the neural mechanisms underlying these dynamics. This paper describes how continuous theta burst transcranial magnetic stimulation may be employed to test the contribution of the posterior medial frontal cortex (and/or other regions) to threat-related ideological shifts.

Video: Continuous Theta Burst Stimulation of the Posterior Medial Frontal Cortex to Experimentally Reduce Ideological Threat Responses

Stimulating the Lip Motor Cortex with Transcranial Magnetic Stimulation

Transcranial magnetic stimulation (TMS) has proven to be a useful tool in investigating the role of the articulatory motor cortex in speech perception. Researchers have used single-pulse and repetitive TMS to stimulate the lip representation in the motor cortex. The excitability of the lip motor representation can be investigated by applying single TMS pulses over this cortical area and recording TMS-induced motor evoked potentials (MEPs) via electrodes attached to the lip muscles (electromyography; EMG). Larger MEPs reflect increased cortical excitability. Studies have shown that excitability increases during listening to speech as well as during&#160;viewing speech-related movements. TMS can be used also to disrupt the lip motor representation. A 15-min train of low-frequency sub-threshold repetitive stimulation has been shown to suppress motor excitability for a further 15-20 min. This TMS-induced disruption of the motor lip representation impairs subsequent performance in demanding speech perception tasks and modulates auditory-cortex responses to speech sounds. These findings are consistent with the suggestion that the motor cortex contributes to speech perception. This article describes how to localize the lip representation in the motor cortex and how to define the appropriate stimulation intensity for carrying out both single-pulse and repetitive TMS experiments.

Transcranial magnetic stimulation (TMS) has proven to be a useful tool in investigating the role of the articulatory motor cortex in speech perception.&#160; This article describes how to record motor evoked potentials (MEPs) from the lip muscles and how to disrupt the motor lip representation using repetitive TMS.

Transcranial magnetic stimulation (TMS) has proven to be a useful tool in investigating the role of the articulatory motor cortex in speech perception. ...

Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical components. Both anxiety and fear can be studied in the laboratory by measuring the potentiation of the startle reflex. The startle reflex is a defensive reflex that is potentiated when an organism is threatened and the need for defense is high. The startle reflex is assessed via electromyography (EMG) in the orbicularis oculi muscle elicited by brief, intense, bursts of acoustic white noise (i.e., &#8220;startle probes&#8221;). Startle potentiation is calculated as the increase in startle response magnitude during presentation of sets of visual threat cues that signal delivery of mild electric shock relative to sets of matched cues that signal the absence of shock (no-threat cues). In the Threat Probability Task, fear is measured via startle potentiation to high probability (100% cue-contingent shock; certain) threat cues whereas anxiety is measured via startle potentiation to low probability (20% cue-contingent shock; uncertain) threat cues. Measurement of startle potentiation during the Threat Probability Task provides an objective and easily implemented alternative to assessment of negative affect via self-report or other methods (e.g., neuroimaging) that may be inappropriate or impractical for some researchers. Startle potentiation has been studied rigorously in both animals (e.g., rodents, non-human primates) and humans which facilitates animal-to-human translational research. Startle potentiation during certain and uncertain threat provides an objective measure of negative affective and distinct emotional states (fear, anxiety) to use in research on psychopathology, substance use/abuse and broadly in affective science. As such, it has been used extensively by clinical scientists interested in psychopathology etiology and by affective scientists interested in individual differences in emotion.

Potentiation of the startle reflex is measured via electromyography of the orbicularis oculi muscle during low (uncertain) and high (certain) probability electric shock threat in the Threat Probability Task. This provides an objective measure of distinct negative emotional states (fear/anxiety) for research on psychopathology, substance use/abuse, and broad affective science.

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical ...

Measuring Attentional Biases for Threat in Children and Adults

Investigators have long been interested in the human propensity for the rapid detection of threatening stimuli. However, until recently, research in this domain has focused almost exclusively on adult participants, completely ignoring the topic of threat detection over the course of development. One of the biggest reasons for the lack of developmental work in this area is likely the absence of a reliable paradigm that can measure perceptual biases for threat in children. To address this issue, we recently designed a modified visual search paradigm similar to the standard adult paradigm that is appropriate for studying threat detection in preschool-aged participants. Here we describe this new procedure. In the general paradigm, we present participants with matrices of color photographs, and ask them to find and touch a target on the screen. Latency to touch the target is recorded. Using a touch-screen monitor makes the procedure simple and easy, allowing us to collect data in participants ranging from 3 years of age to adults. Thus far, the paradigm has consistently shown that both adults and children detect threatening stimuli (e.g., snakes, spiders, angry/fearful faces) more quickly than neutral stimuli (e.g., flowers, mushrooms, happy/neutral faces). Altogether, this procedure provides an important new tool for researchers interested in studying the development of attentional biases for threat.

Here we describe a touch-screen visual search paradigm that can be used to study threat detection across the lifespan. The paradigm has already been used in various studies demonstrating that both children and adults detect threatening stimuli like snakes, spiders, and angry faces faster than non-threatening stimuli.

Investigators have long been interested in the human propensity for the rapid detection of threatening stimuli. However, until recently, research in this ...

Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning

Shuttle-box avoidance learning is a well-established method in behavioral neuroscience and experimental setups were traditionally custom-made; the necessary equipment is now available by several commercial companies. This protocol provides a detailed description of a two-way shuttle-box avoidance learning paradigm in rodents (here Mongolian gerbils; Meriones unguiculatus) in combination with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical electrophysiological in vivo recordings. The detailed protocol is applicable to study multiple aspects of learning behavior and perception in different rodent species.
Site-specific ICMS of auditory cortical circuits as conditioned stimuli here is used as a tool to test the perceptual relevance of specific afferent, efferent and intracortical connections. Distinct activation patterns can be evoked by using different stimulation electrode arrays for local, layer-dependent ICMS or distant ICMS sites. Utilizing behavioral signal detection analysis it can be determined which stimulation strategy is most effective for eliciting a behaviorally detectable and salient signal. Further, parallel multichannel-recordings using different electrode designs (surface electrodes, depth electrodes, etc.) allow for investigating neuronal observables over the time course of such learning processes. It will be discussed how changes of the behavioral design can increase the cognitive complexity (e.g. detection, discrimination, reversal learning).

Shuttle-box avoidance learning is well-established in behavioral neuroscience. This protocol describes how shuttle-box learning in rodents can be combined with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical in vivo recordings as a tool to study multiple aspects of learning and perception.

Shuttle-box avoidance learning is a well-established method in behavioral neuroscience and experimental setups were traditionally custom-made; the ...

Vagus Nerve Stimulation as a Tool to Induce Plasticity in Pathways Relevant for Extinction Learning

Extinction describes the process of attenuating behavioral responses to neutral stimuli when they no longer provide the reinforcement that has been maintaining the behavior. There is close correspondence between fear and human anxiety, and therefore studies of extinction learning might provide insight into the biological nature of anxiety-related disorders such as post-traumatic stress disorder, and they might help to develop strategies to treat them. Preclinical research aims to aid extinction learning and to induce targeted plasticity in extinction circuits to consolidate the newly formed memory. Vagus nerve stimulation (VNS) is a powerful approach that provides tight temporal and circuit-specific release of neurotransmitters, resulting in modulation of neuronal networks engaged in an ongoing task. VNS enhances memory consolidation in both rats and humans, and pairing VNS with exposure to conditioned cues enhances the consolidation of extinction learning in rats. Here, we provide a detailed protocol for the preparation of custom-made parts and the surgical procedures required for VNS in rats. Using this protocol we show how VNS can facilitate the extinction of conditioned fear responses in an auditory fear conditioning task. In addition, we provide evidence that VNS modulates synaptic plasticity in the pathway between the infralimbic (IL) medial prefrontal cortex and the basolateral complex of the amygdala (BLA), which is involved in the expression and modulation of extinction memory.

Vagus nerve stimulation (VNS) has emerged as a tool to induce targeted synaptic plasticity in the forebrain to modify a range of behaviors. This protocol describes how to implement VNS to facilitate the consolidation of fear extinction memory.

Extinction describes the process of attenuating behavioral responses to neutral stimuli when they no longer provide the reinforcement that has been ...

Repetitive Transcranial Magnetic Stimulation to the Unilateral Hemisphere of Rat Brain

Previous rodent models of repetitive transcranial magnetic stimulation (rTMS) adopted whole-brain stimulation instead of unilateral hemispheric rTMS, which is unlike the protocols used for human subjects. We report a successful application of rTMS to the unilateral hemisphere of rat brain. The rTMS was delivered with a low-frequency (1 Hz), high-frequency (20 Hz), or sham stimulation protocol to one side of the brain by using a small 25-mm figure-8 coil. We placed the center of the coil 1 cm lateral to the vertex on the biauricular line and angulated the coil 45&#176; to the ground to minimize a potential direct effect of rTMS on the contralateral cortex. We also used an in-house water cooling system to enable repetitive magnetic stimulation for more than 20 min, even at a 20-Hz stimulation frequency. Increases in the transcriptions of immediate early genes (Arc, Junb, and Egr2) were greater after rTMS than after sham stimulation. After 5 consecutive days of 20-min 1-Hz rTMS, bdnf mRNA expression was significantly higher in stimulated cortex than in contralateral side. The model presented herein will elucidate the molecular mechanisms of rTMS by allowing analysis of the inter-hemispheric difference in its effect.

We applied repetitive transcranial magnetic stimulation (rTMS) to the unilateral hemisphere of rat brain, by placing a 25-mm figure-8 coil 1 cm lateral to the vertex on the biauricular line and angulating the coil by 45&#176;. An in-house water cooling system was used for rTMS for more than 20 min.

Previous rodent models of repetitive transcranial magnetic stimulation (rTMS) adopted whole-brain stimulation instead of unilateral hemispheric rTMS, ...

Automatic Detection of Highly Organized Theta Oscillations in the Murine EEG

Theta activity is generated in the septohippocampal system and can be recorded using deep intrahippocampal electrodes and implantable electroencephalography (EEG) radiotelemetry or tether system approaches. Pharmacologically, hippocampal theta is heterogeneous (see dualistic theory) and can be differentiated into type I and type II theta. These individual EEG subtypes are related to specific cognitive and behavioral states, such as arousal, exploration, learning and memory, higher integrative functions, etc. In neurodegenerative diseases such as Alzheimer&#39;s, structural and functional alterations of the septohippocampal system can result in impaired theta activity/oscillations. A standard quantitative analysis of the hippocampal EEG includes a Fast-Fourier-Transformation (FFT)-based frequency analysis. However, this procedure does not provide details about theta activity in general and highly-organized theta oscillations in particular. In order to obtain detailed information on highly-organized theta oscillations in the hippocampus, we have developed a new analytical approach. This approach allows for time- and cost-effective quantification of the duration of highly-organized theta oscillations and their frequency characteristics.

Theta activity in the hippocampus is related to specific cognitive and behavioral stages. Here, we describe an analytical method to detect highly-organized theta oscillations within the hippocampus using a time-frequency (i.e., wavelet analysis)-based approach.

Theta activity is generated in the septohippocampal system and can be recorded using deep intrahippocampal electrodes and implantable ...

How to Use the H1 Deep Transcranial Magnetic Stimulation Coil for Conditions Other than Depression

Deep transcranial magnetic stimulation (dTMS) is a relatively new technique that uses different coils for the treatment of different neuropathologies. The coils are made of soft copper windings in multiple planes that lie adjacent to the skull. They are located within a special helmet so that their magnetic fields combine and improve depth penetration. The H1 dTMS coil is designed to stimulate bilateral prefrontal cortices with greater effective stimulation over the left than the right. By positioning the left side of the coil close to the left dorsolateral prefrontal cortex (DLPFC), the H1 coil was used in a multisite study, leading to FDA approval for treatment-resistant depression. In this same position, the H1 coil was also explored as a possible treatment for negative symptoms of schizophrenia, bipolar depression, and migraine. When moved to different positions over the subject's skull, the H1 coil was also explored as a possible treatment for other conditions. Such manipulation of the H1 coil was demonstrated for PTSD and alcohol dependence by positioning it over the medial prefrontal cortex (mPFC), for anxiety by positioning it over the right prefrontal cortex (rPFC), for auditory hallucinations and tinnitus by positioning it over the temporoparietal junction (TPJ), and for Parkinson's and fatigue from multiple sclerosis (MS) by positioning it over the motor cortex (MC) and PFC. Corresponding electrical field diagrams measured with an oscilloscope through a saline-filled head are included.

The H1 deep transcranial magnetic stimulation coil is FDA-cleared for the treatment of depression. We demonstrate how to utilize the H1 for other conditions, such as auditory hallucinations and PTSD, by moving the helmet to different locations over the subject's skull.

Deep transcranial magnetic stimulation (dTMS) is a relatively new technique that uses different coils for the treatment of different neuropathologies. The ...

A Community-based Stress Management Program: Using Wearable Devices to Assess Whole Body Physiological Responses in Non-laboratory Settings

A pragmatic breath-based intervention to benefit human performance and stress management is timely and valuable to individuals seeking holistic approaches for emotional regulation and optimizing compensatory reserve mechanisms. This protocol is designed to not only teach mind-body awareness but also to provide feedback utilizing physiological data and survey results. The primary findings of this study showed that heart coherence and alpha variables were significantly correlated after four weeks of the breath-based meditation stress protocol. Meditation and rhythmic breathing produced significant increases in alpha brain activity. These brain physiological responses conformed to the Pleth Variability Index (PVI) changes, suggesting the ability of the human body to enter into a meditative state and effectively manage stress. When assessed after four weeks of daily practicing the techniques employed in the stress management protocol, based on the Five Facet Mindfulness Questionnaire, subjects improved in applying mindfulness skills. The overall mindfulness score, Pleth variability index (PVI), and perfusion index (PI) increased after the 4-week intervention period. Results from electroencephalography (brain waves) were consistent with a meditative state during the post-study follow-up session. This provides evidence that wearable devices are feasible for data collection during a breath-based stress management intervention. This protocol can be easily and efficiently implemented into any study design in which physiological data are desired in a non-laboratory-based setting.

Stress is an unavoidable and persistent component of life and holistic approaches for its management are being considered. A standardized methodology was created to demonstrate the feasibility of a breath-based stress management protocol that can be used with commercially available portable technology.

A pragmatic breath-based intervention to benefit human performance and stress management is timely and valuable to individuals seeking holistic approaches ...

Visualization of Intensity Levels to Reduce the Gap Between Self-Reported and Directly Measured Physical Activity

Physical activity (PA) assessment needs tools that are inexpensive and easy to administer. Common questionnaires inquire time spent in light, moderate, and vigorous PA. However, inaccuracies may occur due to individually different understanding of PA intensity levels. Alternatively used direct measures (e.g., accelerometers) are susceptible to reactivity bias and may lack the ability to capture certain activities. Compared to accelerometer measurement, respondents report more time spent in higher-intensity PA. A video that visualizes PA intensity levels might help to overcome this problem. This report describes the design of a randomized controlled trial as a methodology to investigate the effect of a video on the difference between self-reported and directly measured PA. It is hypothesized that the video reduces the mean difference between the two measures. Individuals from the general population are recruited. Hip-worn accelerometers are used to collect directly measured PA data on seven consecutive days. Afterwards, participants are randomly allocated to the experimental and the control group. The experimental group receives a video demonstration on PA intensity levels and subsequent PA assessment via self-administered computer-assisted questionnaire. The control group receives PA assessment only. Thereafter, the data are processed to compare the difference between self-reported and accelerometer-based moderate-to-vigorous physical activity (MVPA) between the study groups using a two-sample t-test. This methodology is appropriate for investigating the effect of any existing or self-produced video on the difference between the two measurement methods. It can be used not only for persons from the general population, but for a variety of other populations and contexts as accurate measures are needed to evaluate PA levels.

This protocol describes a randomized controlled trial as a method to test the effect of a video demonstration on the intra-individual difference between self-reported and accelerometer-based moderate-to-vigorous physical activity.

Physical activity (PA) assessment needs tools that are inexpensive and easy to administer. Common questionnaires inquire time spent in light, moderate, ...