Pergola Giulio, Foroni Francesco, Mengotti Paola, Argiris Georgette, Rumiati Raffaella Ida
Area of Neuroscience, SISSA, via Bonomea 265, I-34136 Trieste, Italy; Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari Aldo Moro, Piazza Giulio Cesare, 11, I-70124, Bari, Italy.
School of Psychology, Australian Catholic University, NSW, 2135, Australia; Area of Neuroscience, SISSA, via Bonomea 265, I-34136 Trieste, Italy.
Biol Psychol. 2017 Oct;129:282-292. doi: 10.1016/j.biopsycho.2017.09.001. Epub 2017 Sep 9.
Visual recognition of objects may rely on different features depending on the category to which they belong. Recognizing natural objects, such as fruits and plants, weighs more on their perceptual attributes, whereas recognizing man-made objects, such as tools or vehicles, weighs more upon the functions and actions they enable. Edible objects are perceptually rich but also prepared for specific functions, therefore it is unclear how perceptual and functional attributes affect their recognition. Two event-related potentials experiments investigated: (i) whether food categorization in the brain is differentially modulated by sensory and functional attributes, depending on whether the food is natural or transformed; (ii) whether these processes are modulated by participants' body mass index. In experiment 1, healthy normal-weight participants were presented with a sentence (prime) and a photograph of a food. Primes described either a sensory feature ('It tastes sweet') or a functional feature ('It is suitable for a wedding party') of the food, while photographs depicted either a natural (e.g., cherry) or a transformed food (e.g., pizza). Prime-feature pairs were either congruent or incongruent. This design aimed at modulating N400-like components elicited by semantic processing. In experiment 1, N400-like amplitude was significantly larger for transformed food than for natural food with sensory primes, and vice versa with functional primes. In experiment 2, underweight and obese women performed the same semantic task. We found that, while the N400-like component in obese participants was modulated by sensory-functional primes only for transformed food, the same modulation was found in underweight participants only for natural food. These findings suggest that the level of food transformation interacts with participants' body mass index in modulating food perception and the underlying brain processing.
对物体的视觉识别可能依赖于不同的特征，这取决于它们所属的类别。识别自然物体，如水果和植物，更多地依赖于它们的感知属性，而识别人造物体，如工具或车辆，则更多地依赖于它们所具备的功能和用途。可食用物体在感知上丰富多样，但也具备特定功能，因此尚不清楚感知属性和功能属性如何影响对它们的识别。两项事件相关电位实验进行了如下研究：（i）大脑中食物分类是否会根据食物是天然的还是经过加工的，而受到感官和功能属性的不同调节；（ii）这些过程是否会受到参与者体重指数的调节。在实验1中，向健康的正常体重参与者呈现一个句子（启动刺激）和一张食物照片。启动刺激描述了食物的要么是感官特征（“它尝起来很甜”）要么是功能特征（“它适合婚宴”），而照片展示的要么是天然食物（如樱桃）要么是加工食物（如披萨）。启动刺激 - 特征对要么是一致的要么是不一致的。这种设计旨在调节由语义加工引发的类似N400的成分。在实验1中，对于经过加工的食物，当启动刺激是感官特征时，类似N400的波幅显著大于天然食物，反之，当启动刺激是功能特征时则相反。在实验2中，体重过轻和肥胖的女性执行相同的语义任务。我们发现，虽然肥胖参与者中类似N400的成分仅在加工食物时受到感官 - 功能启动刺激的调节，但体重过轻的参与者中，同样的调节仅在天然食物时出现。这些发现表明，食物加工水平与参与者的体重指数相互作用以调节食物感知及潜在的大脑加工过程。
