Table 2 rTMS and tDCS studies in decision making

rTMS

Buckholtz et al. 2015 [9]

blameworthiness and punishment decisions

66 (M32)/2 x 2 between-groups design, with rTMS condition (active versus sham) and hemisphere (left versus right DLPFC) as between-subject factors.

R or L DLPFC/1 Hz rTMS stimulation and sham. The maximum stimulation duration in any one session was approximately 30 min, constraining each of the two rating sessions to 15 min. The two sessions were separated by no less than 48 hr and no more than 2 weeks.

LF rTMS over DLPFC lowerd punishment for culpable acts, but did not affect blameworthiness judgments.

Camus et al. 2009 [10]

food choice

56 (M30) - Exp1 & 15 (M8) - Exp 2

R DLPFC/1 Hz-rTMS/Two control groups (1 Hz-rTMS - vertex and sham)/Stimulation intensity: 50 % of the stimulator maximum. A single, 15 min, 1 Hz rTMS train (900 pulses). 1st control group (15 min, 1 Hz rTMS train at 50% of the stimulator maximum). 2nd control group - sham rTMS over the right DLPFC,

1 Hz-rTMS to the R DLPFC decreased values assigned to food stimuli

Cho et al. 2015 [13]

delay discounting

24 (F11)/Within-subject design

MPFC and vertex stimulation (control condition)/10 Hz-rTMS. Stimulus intensity: 80% of the active motor threshold/Applied during the behavior study with the delay discounting task

10 Hz-rTMS to the MPFC increased the preference toward delayed larger-size rewards and decreased the choices for immediate small-size rewards.

Gongora et al. 2016 [25]

visuomotor task involving decision making

12 (M4)

Superior Parietal Cortex (SPC; Brodmann area 7)/1 Hz – 15 min – 80 % Resting Motor Threshold (15 min)

Absolute beta power decreased in Fp1 and increased in Fp2 at rest before task, but Fp2’s absolute beta power increased during the task, and F4’s abolute beta power decreased, and F7’s abolute beta power increased during the task and decresed at rest after task. The parietal regions (P3, Pz and P4)’s abolute beta power decreased during the visuomotor task, compared to rest conditions.

Ishibashi et al. 2011 [33]

function and manipulation tool knowledge

13 (F6)

L lateral ATL and L IPL, occipital pole (control site)/Inhibitory rTMS/Stimulation was delivered at 120 % of motor threshold but kept at 67 % of the device’s maximum output if it exceeded this criterion (This occurred in 16.7 % of the sessions). Average stimulation intensity was 58.8%. Participants received 10-min of TMS stimulation (1 Hz for 600 s).

Inhibitory rTMS to L lateral ATL increased RT for the “function” judgments, whereas inhibitory rTMS of L IPL increased RT for the “manipulation” judgments.

Koch et al. 2005 [36]

spatial working memory

9 (F4)

R posterior parietal cortex (PPC), R premotor cortex (SFG), and R DLPFC/HF rTMS (25 Hz)/rTMS trains of eight stimuli at 25-Hz frequency (mean stimulation time: 300 ms) were delivered at an intensity of 110 % of motor threshold

Both HF rTMS - R posterior parietal cortex (PPC) and R DLPFC increased RT during the delay phase (no effect observed for R SFG). HF rTMS - R DLPFC increased RT selectively during the decision phase

Philiastides et al. 2011 [57]

perception

12 (F8)

L DLPFC/LF rTMS and sham/Stimulation intensity: 110% of motor threshold/Two separate 12 min rTMS sessions: a 1 Hz LF rTMS to the L DLPFC and a 12 min sham rTMS over the same area

Decreased accuracy and increased RT

Sheffer et al. 2013 [69]

delay discounting

47 smokers & 19 nonsmokers/Single-blind, within-subjects design

L DLPFC/Three sessions of HF rTMS (20Hz, 10 Hz, sham)/900 pulses of HF rTMS (20 Hz, 10 Hz, sham) separated by at least 48 hours - 20 Hz & 10 Hz (110 % MT, 1 second on, 20 seconds off), sham (10 Hz, 1 second on, 20 seconds off, 5.5 mA)

HF rTMS to the L DLPFC decreased discounting of monetary gains and increased discounting of monetary losses in both smokers and nonsmokers, but had no effect on cigarette consumption in smokers

Studer et al. 2014 [71]

visuospatial attention

28 (M15)/Within-subject design (separated by 6–8 days)

Inhibitory cTBS - AG bilaterally, cTBS - PMC bilaterally (active control condition) and without stimulation/Consisting of bursts of three pulses at 50 Hz repeated at 5 Hz for 30 s (450 pulses) per hemisphere. Stimulation intensity: 40 % of maximum machine output.

cTBS - AG affects decision-making tasks requiring visuospatial attention by disrupting the relationship between decision latencies and the probability of winning/losing.

Tassy et al. 2012 [72]

moral judgment

24

R DLPFC/1 Hz-rTMS (a single, 15-min, 900 pulses) or sham/Stimulation intensity: 54 % of the stimulator maximum output

1 Hz-rTMS to the R DLPFC increased utilitarian responses during objective evaluation of moral dilemmas,

Viggiano et al. 2008 [77]

object identification

39 (F25)

No rTMS (baseline), real rTMS (L DLPFC), real rTMS (R DLPFC), and sham rTMS (L DLPFC)/10 Hz-rTMS/An intensity of 90 % RMT of the contralateral FDI/6 pulses (train duration 500 ms)

rTMS of either L or R DLPFC increased the RT for spatially filtered living stimuli, but not of non-filtered living stimuli or of non-living objects.

tDCS

Bogdanov et al. 2015 [4]

Sunk-cost effect (Cost of past expenses)

60 (F30)/Double-blind, sham-controlled, between-subject design.

R DLPFC (F4), a reference - CZ. Anodal, cathodal, or sham stimulation. A current of 1.075 μA, leading to a current density of 0.043 mA/cm² for the electrode over the DLPFC and 0.011 mA/cm² for the reference electrode. The stimulation lasted for as long as the individual participant worked on the investment task but not longer than 30 min.

Anodal tDCS significantly increased a sunk-cost effect, but cathodal or sham stimulation did not change it. Also, tDCS did not influence choices when there were no investments.

Boggio et al. 2010a [5]

risk-taking behavior

28 (M3, aged 50–85 years)/Single-center, doubled-blinded, randomized and sham-controlled trial

DLPFC/R anodal/L cathodal tDCS, L anodal/R cathodal tDCS, or sham stimulation. 2 mA. tDCS started 5 min before the task began and was delivered during the entire course of the risk task (10 min)

L anodal/R cathodal tDCS group caused more often high-risk prospects compared to sham or R anodal/L cathodal stimulation groups.

Boggio et al. 2010b [6]

addiction

25 marijuana users (M15)/Single-center, doubled-blinded, randomized, and sham-controlled trial

DLPFC/L anodal/R cathodal tDCS, R anodal/L cathodal tDCS, or sham stimulation. 2 mA. The tDCS started 5 min before the task began and was delivered during the entire course of the risk task (10 min)

Both L anodal/R cathodal tDCS of DLPFC and R anodal/L cathodal tDCS showed more risky tendencies in marijuana users. In marijuana users, R anodal/L cathodal tDCS decreased marijuana cravings.

Cheng & Lee 2015 [12]

risk-taking behavior

16/Single-blind, within-subjects design (3 experimental sessions on separate days)

DLPFC/left anodal/right cathodal, left cathodal/right anodal, or sham stimulation. 2 mA, Stimulation began 5 minutes before onset of experimental tasks and continued throughout completion of all tasks (within 19 minutes)

Left cathodal/right anodal tDCS over DLPFC decreased risk-taking under a context of haste. The reduction of risk-taking was larger in more impulsive individuals.

Fecteau et al. 2007a [18]

risk-taking behavior

36 (M11)/Single-blind desgin

DLPFC/R anodal/L cathodal tDCS, L anodal/R cathodal tDCS, or sham stimulation. 2 mA. tDCS started 5 min before the task began and was delivered during the entire course of the risk task (<10 min)

R anodal/L cathodal tDCS caused the safe prospect more often, compared to L anodal/R cathodal and sham stimulation

Fecteau et al. 2007b [19]

risk-taking behavior

35 (M9)/Single-blind desgin

DLPFC/R anodal/L cathodal tDCS, L anodal/R cathodal tDCS or sham stimulation. 2 mA. tDCS started 5 min before the task began and was delivered during the whole course of the BART (<15 min)

Groups receiving anodal tDCS over R or L DLPFC showed a risk-averse response.

Fecteau et al. 2014 [17]

addiction

12 smokers (M5)/Two five-day tDCS (active or sham) - A crossover, blind at four levels (group allocator, subjects, tDCS provider, outcome assessor), randomized, sham-controlled design (3 months separated the two tDCS regimens)

DLPFC/Active tDCS (R anodal/L cathodal tDCS) and sham stimulation. 2 mA for 30 min

Active tDCS decreased significantly the number of cigarettes smoked compared to sham stimulation and the effects maintained for 4 days.

Filmer et al. 2013 [22]

dual-task performance

18 (M3)/tDCS during three testing sessions on different days (The average time between sessions: 5 days)

L posterior lateral prefrontal cortex (pLPFC)/Anodal (9 min), cathodal (9 min), or sham (1 min 15 sec). Reference electrode - R supraorbital region/Current density: 0.029 mA/cm 2 (current intensity = 0.7 mA).

Cathodal tDCS to L pLPFC reduced RT for the multitask session.

Fregni et al. 2008 [23]

food craving

23 (F21) - 21 completed the entire study (3 different sessions of treatment) (at 48-hour intervals)/Placebo-tDCS-controlled, randomized, double-blind, crossover study

DLPFC/L anode/R cathode tDCS, R anode/L cathode tDCS, and sham tDCS. 2 mA for 20 min.

Sham stimulation increased craving, but anode L/cathode R tDCS did not increase craving (anode L/cathode R can suppress food craving).

Gorini et al. 2014 [26]

addiction

18 cocaine users (M10) & 18 non-abusers/Single-blind, sham-controlled study

DLPFC. L anodal/R cathodal tDCS, R anodal/L cathodal tDCS, or sham stimulation (at least 48-hour intervals). 1.5 mA for 20 min.

BART: both cocaine users and non-abusers decreased risky behavior after both active tDCS. GDT: cocaine users increased safe behavior after R anodal stimulation and increased risk-taking behavior after L anodal stimulation, whereas control subjects increased safe behavior by only R anodal stimulation.

Hecht et al. 2010 [29]

probabilistic guessing

28 (M14)

DLPFC/R anodal/L cathodal group, L anodal/R cathodal group, or control group (no stimulation). 2 mA. tDCS started immediately before the prediction task began and was delivered during the whole course of the five-block experimen (~22 min)

No difference in strategy between the three groups, but participants in the left anodal/right cathodal group decreased RT when choosing the most frequent alternative.

Hecht et al. 2013 [30]

delay discounting

14 (F7)/Within-subject design (a minimum of 2 days (~47 h) interval between sessions)

DLPFC/R anodal/L cathodal tDCS, L anodal/R cathodal DLPFC tDCS, and sham stimulation 1.6 mA for 20 min

Anodal left/cathodal R DLPFC tDCS increased smaller immediate gains rather than larger-delayed options compared to sham stimulation.

Javadi et al. 2015 [34]

perceptual decision-making

12 (F6) - Exp1 & 45 (F26) - Exp2/Exp1 (n = 12) - only one stimulation condition (bilateral stimulation) & Exp2 (n = 45) - three stimulation conditions (bilateral, anodal unilateral, and cathodal unilateral stimulations)

Primary motor cortex (PMC) (C3 and C4)/Bilateral tDCS (L anodal PMC/R cathodal PMC, R anodal PMC/L cathodal PMC), Unilateral-anodal tDCS (L anodal PMC/R upper arm, R anodal PMC/L upper arm), Unilateral-cathodal tDCS (L cathodal PMC/R upper arm, R cathodal PMC/L upper arm)/1.5 mA for 10 min after the first phase and continued for another 5 min during the second phase.

Anodal tDCS over the PMC increased responses using the contralateral hand; whereas, cathodal tDCS over the PMC increased responses using the ipsilateral hand. In all tDCS conditions, RTs decreased when response shifted toward left hand and increased when response shifted away from the left hand.

Kekic et al. 2014 [35]

food craving

F 20 with frequent food cravings/A double-blind sham-controlled within-subjects crossoverdesign

DLPFC/R anodal/L cathodal tDCS and sham tDCS. 2mA for 20 min.

Active tDCS decreased craving for sweet foods, but not savory foods

Kuehne et al. 2015 [37]

moral judgment

F 20 with frequent food cravings/A double-blind sham-controlled within-subjects crossoverdesign

Anodal, cathodal, and sham stimulation - L DLPFC (reference electrode: R parietal cortex (P4). 10 min of tDCS before starting with the moral judgment task, with 2 mA and 5 seconds fade-in time. The stimulation continued and participants rated the personal moral dilemmas. The maximum stimulation time did not exceed 20min

Anodal stimulation - L DLPFC decreased individual appropriateness ratings and shifted toward non-utilitarian actions.

Mengarelli et al. 2015 [46]

choice modulation

48 (F28)

DLPFC, L cathodal tDCS, R cathodal tDCS (anode electrode - contralateral supraorbital area), or sham stimulation (over the same cortical areas, with the cathode electrode over the left and the right, respectively). 1 mA for 15 min

Cathodal tDCS - L DLPFC reduced choice-induced preference change.

Minati et al. 2012 [47]

risk-taking behavior

F47/Single-blind design

Three groups of female subjects (L anodal/R cathodal, R anodal/L cathodal, and sham tDCS)/DLPFC. 2 mA. Stimulation was enabled approximately 3 min before starting the task and disabled immediately upon completion (about 20.5 min)

R anodal/L cathodal tDCS significantly increased response confidence, independently of accept/reject response

Ouellet et al. 2015 [42]

decision-making and cognitive impulse control

45 (F29)/A single-blind, three-arm, randomized and sham-controlled study.

Orbitofrontal cortex (OFC)/L anodal left/R catrhodal, R anodal left/L catrhodal, or sham/1.5 mA for 30 min. Anodal and cathodal current densities of 0.04 mA/cm 2 and 0.027 mA/cm 2, respectively.

Anodal tDCS over orbitofrontal cortex (OFC) regardless of laterality increased advantageous decision-making and cognitive impulse control, compared to sham tDCS.

Pripfl et al. 2013 [60]

addiction

18 smokers (F10) & 18 non-smokers (F15)/Within-subjects design (at least 1 week between sessions).

DLPFC/R anodal/L cathodal tDCS, L anodal/R cathodal tDCS, and sham stimulation. 0.45 mA (delivered over an electrode size of about 5 cm²) for 15 min

In both the smoking and nonsmoking groups, risk taking was decreased in the “cold” task after the anodal left tDCS, whereas the opposite effect was seen in the “hot” task after anodal right tDCS.

Raja Beharelle et al. 2015 [61]

Exploration-exploitation trade-offs

79(F23)/Double-blind design

R Frontopolar Cortex (MNI peak: x = 27, y = 57, z = 6)/Anodal, cathodal, or sham tDCS/1 mA. The stimulation 3 min before subjects started the bandit task and continued throughout tasks

Cathodal stimulation increased choices of the highest rewards, but anodal stimulation influenced choices less by anticipated rewards, but rather by recent negative reward prediction errors

Smittenaar et al. 2014 [70]

model-based learning

22 (F11)/Within-subject, double-blind

R DLPFC/Anodal tDCS (cathodal electrode over the inion) and sham stimulation)/2 mA for 25 min.

One stimuli was more strongly associated with the originally selected stimuli than the other. Active tDCS does not significantly affect model-based or model-free control during a behavioral task.

Woods et al. 2014 [79]

perception of space and time

16 (F10)/Three sessions on separate days (time range between sessions: 6–8 days).

Frontal - R anodal (F4)/L cathodal (F3), parietal - R anodal (CP4)/L cathodal (CP3) (1.5 mA for 20 min) or sham stimulations (F3/F4 or CP3/CP4 - counterbalanced across participants.

Parietal stimulation affected perception of spatial causality, while the frontal stimulation affected perception of both spatial and temporal causality.

Xu et al. 2013 [80]

addiction

24 smokers (F3)/Single-blind design

Anode tDCS - L DLPFC/cathode tDCS - R supra-orbital area (2 mA for 20 min) and sham stimulation

Anode tDCS - L DLPFC and cathode tDCS - R supra-orbital area decreased significantly negative affect.

Xue et al. 2012 [81]

maladaptive decision-making

18 (M9)

LPFC (the intersection of the F3–T3 line and the F7–C3 line)/Anodal tDCS - left lateral prefrontal cortex Control condition - Visual cortex (VC), Reference electrode - left cheek/1.5 mA for 10 min

Anodal tDCS - left LPFC increased the use of the gambler’s fallacy strategy.

Ye et al. 2015a [82],

risk-taking behavior

60 (F36)

DLPFC/R anodal/L cathodal tDCS, L anodal/R cathodal tDCS or sham stimulation/2 mA for 15 min

Group receiving sham stimulation showed more conservative and safe options. Groups receiving either R anodal/L cathodal tDCS or L anodal/R cathodal tDCS did not show significant changes after tDCS.

Ye et al. 2015b [83]

risk-taking behavior

60 (F35)

R anodal/L cathodal DLPFC, L anodal/R cathodal DLPFC, or sham stimulation/2 mA for 15 min + another 3 min (second task)

R anodal/L cathodal tDCS induced more risky options in the gain frame and more safe options in the loss frame.