García-Marco Enrique, Nuez Trujillo Aarón, Padrón Iván, Ravelo Yennifer, Fu Yang, Marrero Hipólito
Department of Clinical and Experimental Psychology, University of Huelva, Huelva, Spain.
Institute of Neurosciences, University of La Laguna, San Cristobal de La Laguna, Spain.
Front Psychol. 2024 May 3;15:1356030. doi: 10.3389/fpsyg.2024.1356030. eCollection 2024.
In the process of comprehension, linguistic negation induces inhibition of negated scenarios. Numerous studies have highlighted the role of the right Inferior Frontal Gyrus (rIFG) - a key component of the inhibitory network - in negation processing. Social avoidance can be linguistically portrayed using attitudinal verbs such as "exclude" vs. "include", which inherently carry negative connotations. Consequently, we hypothesize that the interplay between explicit negation and the implicit negativity of avoidance verbs can be modulated via transcranial direct current stimulation (tDCS) targeting the rIFG.
In our study, sixty-four participants read approach/avoidance sentences, which were either affirmative or negative, such as "Anne included (did not include) meat in her diet" vs. "Anne excluded (did not exclude) meat in her diet". This reading task followed a 20-minute tDCS session. The sentences were sequentially displayed, and at 1500 ms post-sentence, a verb was shown - either the one previously mentioned or its semantic alternative counterpart (e.g., included vs. excluded).
Findings revealed that anodal stimulation intensifies the inhibitory impact of negation during sentence comprehension. Under anodal conditions, negative sentences led to extended reading times for the mentioned verbs compared to their affirmative counterparts, suggesting an increased inhibitory effect on the verb. Furthermore, in avoidance sentences, anodal stimulation resulted in reduced reading times for alternative verbs (e.g. "included") in negative sentences compared to alternative verbs (e.g. "excluded") in negated approach sentences.
As "avoidance" is semantically equivalent to "non-approach", the inhibitory effect of negation is primarily applied to the implicit negation: NOT EXCLUDED = NOT→NOT (INCLUDED), which consequently activates the representation of the alternative verb making it more available. We further discuss these findings in light of the rIFG's pivotal role in processing attitudinal verbs and linguistic negation. This discussion is framed within the overarching context of the two-step model of negation processing, highlighting its significance in the realm of social communication.
在理解过程中，语言否定会引发对被否定情境的抑制。众多研究强调了右额下回（rIFG）——抑制网络的关键组成部分——在否定处理中的作用。社会回避可以通过诸如“排除”与“包含”等态度动词在语言上进行描述，这些动词本身带有负面含义。因此，我们假设通过针对rIFG的经颅直流电刺激（tDCS），可以调节明确否定与回避动词隐含否定之间的相互作用。
在我们的研究中，64名参与者阅读接近/回避句子，这些句子要么是肯定的，要么是否定的，例如“安妮在饮食中包含（不包含）肉类”与“安妮在饮食中排除（不排除）肉类”。这个阅读任务在20分钟的tDCS疗程之后进行。句子依次显示，在句子出现后1500毫秒，会显示一个动词——要么是之前提到的那个，要么是其语义替代对应词（例如，包含与排除）。
研究结果显示，阳极刺激会增强句子理解过程中否定的抑制作用。在阳极条件下，与肯定句子相比，否定句子会导致对所提及动词的阅读时间延长，这表明对动词的抑制作用增强。此外，在回避句子中，与否定接近句子中的替代动词（例如“排除”）相比，阳极刺激导致否定句子中替代动词（例如“包含”）的阅读时间缩短。
由于“回避”在语义上等同于“不接近”，否定的抑制作用主要应用于隐含否定：不排除=非→非（包含），这进而激活了替代动词的表征，使其更容易被获取。我们根据rIFG在处理态度动词和语言否定中的关键作用，进一步讨论这些发现。这一讨论是在否定处理的两步模型的总体背景下进行的，突出了其在社会交流领域的重要性。
