Limits...
Cathodal Transcranial Direct Current Stimulation on the Right Temporo-Parietal Junction Modulates the Use of Mitigating Circumstances during Moral Judgments.

Leloup L, Miletich DD, Andriet G, Vandermeeren Y, Samson D - Front Hum Neurosci (2016)

Bottom Line: In the current study, we found that tDCS specifically affected accidental harms but not attempted harms.Our pattern of results in the context of our experimental design can best be explained by a causal role of the rTPJ in processing the mitigating circumstances which reduce a protagonist's moral responsibility.We discuss these results in relation to the idea that the rTPJ may play multiple roles in moral cognition and in relation to methodological aspects related to the use of tDCS.

View Article: PubMed Central - PubMed

Affiliation: Psychological Sciences Research Institute, Université catholique de Louvain, Louvain-la-Neuve Belgium.

ABSTRACT
Recently, a few transcranial magnetic stimulation or transcranial direct current stimulation (tDCS) studies have shown that the right temporo-parietal junction (rTPJ) plays a causal role in moral reasoning especially in cases of accidental harms or attempted harms. The profile of results across studies is, however, not entirely consistent: sometimes the stimulation affects predominantly attempted harms while sometimes the stimulation affects predominantly accidental harms. We argue that such discrepancy could reflect different functional contributions of the rTPJ in moral judgments and that the chosen design parameters or stimulation method may differentially bring to light one or the other functional role of the rTPJ. In the current study, we found that tDCS specifically affected accidental harms but not attempted harms. Low cathodal stimulation of the rTPJ led to a marginally significant increase in the severity of judgments of accidental harms (Experiment 1) while higher cathodal current density led to a highly significant decrease in the severity of judgments of accidental harms (Experiment 2). Our pattern of results in the context of our experimental design can best be explained by a causal role of the rTPJ in processing the mitigating circumstances which reduce a protagonist's moral responsibility. We discuss these results in relation to the idea that the rTPJ may play multiple roles in moral cognition and in relation to methodological aspects related to the use of tDCS.

No MeSH data available.


Mean number of punishment tokens (from 0 “No punishment” to 6 “Strong punishment”) as a function of moral scenarios (Intentional harm scenarios, Attempted harm scenarios, Accidental harm scenarios, and Neutral scenarios) and time (Pre-stimulation and Post-stimulation) for the Cathodal Group, the Anodal Group, and the Sham Group. Error bars represent standard mean error. (*)p < 0.10; *p < 0.05; **p < 0.01.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4940443&req=5

Figure 3: Mean number of punishment tokens (from 0 “No punishment” to 6 “Strong punishment”) as a function of moral scenarios (Intentional harm scenarios, Attempted harm scenarios, Accidental harm scenarios, and Neutral scenarios) and time (Pre-stimulation and Post-stimulation) for the Cathodal Group, the Anodal Group, and the Sham Group. Error bars represent standard mean error. (*)p < 0.10; *p < 0.05; **p < 0.01.

Mentions: In the anodal stimulation condition, no effect involving Time reached the significance level [all F(1,23) < 2.107, all p > 0.160, all < 0.084]. In the cathodal stimulation condition, there was a significant three way Intention by Outcome by Time interaction effect [F(1,23) = 9.463; p = 0.005, = 0.292]. Paired-wise comparisons comparing pre-stimulation with post-stimulation ratings for each of the four types of scenarios (neutral scenarios, accidental harm scenarios, attempted harm scenarios, and intentional harm scenarios) showed that the ratings only changed for one type of scenarios, namely the accidental harm scenarios [t(23) = 3.076, p = 0.005, d = 0.677], with a significance decrease in the severity of punishment rating following tDCS stimulation (pre-stimulation: 1.52 ± 0.23; post-stimulation: 1.18 ± 0.19). This effect of cathodal stimulation on the accidental harm scenarios remained significant after applying a Bonferroni correction for multiple comparisons (the adjusted threshold for significance in case of six paired-wise comparisons is 0.05/6 = 0.008). In the sham condition, there was a significant Intention by Time interaction effect [F(1,23) = 5.685, p = 0.026, = 0.198], however, none of the paired-wise comparisons comparing pre-stimulation with post-stimulation ratings reached significance [intention to harm : t(23) = -1.644, p = 0.114, d = 0.335; no intention to harm : t(23) = 1.757, p = 0.092, d = 0.350; Figure 3].


Cathodal Transcranial Direct Current Stimulation on the Right Temporo-Parietal Junction Modulates the Use of Mitigating Circumstances during Moral Judgments.

Leloup L, Miletich DD, Andriet G, Vandermeeren Y, Samson D - Front Hum Neurosci (2016)

Mean number of punishment tokens (from 0 “No punishment” to 6 “Strong punishment”) as a function of moral scenarios (Intentional harm scenarios, Attempted harm scenarios, Accidental harm scenarios, and Neutral scenarios) and time (Pre-stimulation and Post-stimulation) for the Cathodal Group, the Anodal Group, and the Sham Group. Error bars represent standard mean error. (*)p < 0.10; *p < 0.05; **p < 0.01.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940443&req=5

Figure 3: Mean number of punishment tokens (from 0 “No punishment” to 6 “Strong punishment”) as a function of moral scenarios (Intentional harm scenarios, Attempted harm scenarios, Accidental harm scenarios, and Neutral scenarios) and time (Pre-stimulation and Post-stimulation) for the Cathodal Group, the Anodal Group, and the Sham Group. Error bars represent standard mean error. (*)p < 0.10; *p < 0.05; **p < 0.01.
Mentions: In the anodal stimulation condition, no effect involving Time reached the significance level [all F(1,23) < 2.107, all p > 0.160, all < 0.084]. In the cathodal stimulation condition, there was a significant three way Intention by Outcome by Time interaction effect [F(1,23) = 9.463; p = 0.005, = 0.292]. Paired-wise comparisons comparing pre-stimulation with post-stimulation ratings for each of the four types of scenarios (neutral scenarios, accidental harm scenarios, attempted harm scenarios, and intentional harm scenarios) showed that the ratings only changed for one type of scenarios, namely the accidental harm scenarios [t(23) = 3.076, p = 0.005, d = 0.677], with a significance decrease in the severity of punishment rating following tDCS stimulation (pre-stimulation: 1.52 ± 0.23; post-stimulation: 1.18 ± 0.19). This effect of cathodal stimulation on the accidental harm scenarios remained significant after applying a Bonferroni correction for multiple comparisons (the adjusted threshold for significance in case of six paired-wise comparisons is 0.05/6 = 0.008). In the sham condition, there was a significant Intention by Time interaction effect [F(1,23) = 5.685, p = 0.026, = 0.198], however, none of the paired-wise comparisons comparing pre-stimulation with post-stimulation ratings reached significance [intention to harm : t(23) = -1.644, p = 0.114, d = 0.335; no intention to harm : t(23) = 1.757, p = 0.092, d = 0.350; Figure 3].

Bottom Line: In the current study, we found that tDCS specifically affected accidental harms but not attempted harms.Our pattern of results in the context of our experimental design can best be explained by a causal role of the rTPJ in processing the mitigating circumstances which reduce a protagonist's moral responsibility.We discuss these results in relation to the idea that the rTPJ may play multiple roles in moral cognition and in relation to methodological aspects related to the use of tDCS.

View Article: PubMed Central - PubMed

Affiliation: Psychological Sciences Research Institute, Université catholique de Louvain, Louvain-la-Neuve Belgium.

ABSTRACT
Recently, a few transcranial magnetic stimulation or transcranial direct current stimulation (tDCS) studies have shown that the right temporo-parietal junction (rTPJ) plays a causal role in moral reasoning especially in cases of accidental harms or attempted harms. The profile of results across studies is, however, not entirely consistent: sometimes the stimulation affects predominantly attempted harms while sometimes the stimulation affects predominantly accidental harms. We argue that such discrepancy could reflect different functional contributions of the rTPJ in moral judgments and that the chosen design parameters or stimulation method may differentially bring to light one or the other functional role of the rTPJ. In the current study, we found that tDCS specifically affected accidental harms but not attempted harms. Low cathodal stimulation of the rTPJ led to a marginally significant increase in the severity of judgments of accidental harms (Experiment 1) while higher cathodal current density led to a highly significant decrease in the severity of judgments of accidental harms (Experiment 2). Our pattern of results in the context of our experimental design can best be explained by a causal role of the rTPJ in processing the mitigating circumstances which reduce a protagonist's moral responsibility. We discuss these results in relation to the idea that the rTPJ may play multiple roles in moral cognition and in relation to methodological aspects related to the use of tDCS.

No MeSH data available.