An essential aspect of Lindquist et al.'s proposal in the target article concerns the attack on the classic attempt to functionally parcellate the brain, according to which, given a linguistically described mental process, a specific brain area underpinning it can be found. From the experimental point of view, the endorsement of such a “one word-one area” account of the mental domain has already shown its limits in the case of the classic cognitivist description of the mental processes underlying social cognition. According to this view, specific brain sites have been postulated to underpin the attribution of mental states to others by means of linguistic-like propositional attitudes, stimulating the search for a theory of mind reading brain modules. We do agree with the authors that such a transposition from language to brain sites could hinder our understanding of the brain, and we fully appreciate their view that words are “essence placeholders” (target article, sect. 3, see “Definitions”), helping to create categories in the absence of strong statistical regularities. The fact that different words designate different emotional states does not necessarily imply that such states can be directly mapped within specific brain locations.

Lindquist et al. frame this criticism within the locationist–constructionist debate, supporting the view that single emotions are not represented in specific brain regions, but rather are constituted by basic psychological operations common across different emotional domains. Despite the intriguing view they propose, however, the authors fail to describe what, according to a locationist approach, a cortical site for a given emotion is supposed to represent. This omission weakens the locationist approach, making it easier to criticize it. Consider the case of the insula. The authors claim that a locationist approach describes the insula as a region where disgust is processed; this view is then compared to a constructionist approach, according to which the insula is involved in “representing core affective feelings in awareness” (sect. 5.2., para. 2). Whereas the constructionist proposal is clearly explained, it is not as comprehensible what, according to the locationist approach, the insula is supposed to process (“perceiving instances of disgust,” sect. 5.2., para. 1, italics in original).

In our view, this uncertainty is connected to the perspective that having an emotion is a “perceptual act” (see sect. 3, para. 2) during which the emotion “emerges in consciousness.” According to the classic perspective the authors seem to endorse, experiencing a given emotion is similar to having a sensation, that is, it means feeling something. However, in their view, differently from sensations, emotions depend upon the “internal” world or, to use the authors' description, “core affect.” It follows that experiencing and expressing a given emotion are two different and independent processes. The view that feeling emotions is a sensory activity, totally independent from their motor expression, is an old idea among scholars of emotions. In his seminal work, Darwin (Reference Darwin1872) considered the emotion as a feeling preceding the emotional expression, whereas James (Reference James1884) considered the emotion as a feeling consequent to the emotional expression. In both cases, the motor output is not considered to be part of the emotion itself. The heritage of Darwin's and James's views strongly influenced contemporary neuroscientists, who mostly accept the experience/expression dichotomy, considering the emotional experience as a specific type of sensory activity (Craig Reference Craig2002; Critchley et al. Reference Critchley, Wiens, Rotshtein, Ohman and Dolan2004; Damasio Reference Damasio1999). This perspective is clearly endorsed also by the authors of the target article.

An alternative perspective was offered, however, by Dewey (Reference Dewey1894) and Mead (Reference Mead1895; Reference Mead1934). Both Dewey and Mead explicitly criticized the experience/expression dichotomy by stressing the lack of any proof of the previous existence of the emotions with respect to the emotional response. In contrast, they suggested that the behavior connected to a specific emotion is part of the emotion itself. The sensory patterns directly trigger the motor representations associated with that specific emotion and this sensory–motor match is the emotion. The link between experience and expression has been partially recognized by recent neuroscientific studies. Botox injection in facial muscles decreases the strength of emotional experience (Davis et al. Reference Davis, Senghas, Brandt and Ochsner2010). Activity in the left amygdala and in the brainstem is reduced during imitation of angry facial expression, if Botox is injected into the frown muscles (Hennenlotter et al. Reference Hennenlotter, Dresel, Castrop, Ceballos-Baumann, Wohlshlager and Haslinger2009). This effect likely reduces both the sensory input and the visceromotor output controlled by these structures. Even inducing the production of an emotional expression, or posture, enhances the correspondent emotional experience and influences the normal processing of the emotional information (Niedenthal Reference Niedenthal2007).

Even more dramatic is the case of the insula, described by Lindquist et al. as a region involved in the mental representation of bodily sensations. Recently, we showed that two different emotional behaviors can be evoked by the intracortical microstimulation (ICMS) of two different sectors of the macaque monkey insula (Caruana et al. Reference Caruana, Jezzini, Sbriscia-Fioretti, Rizzolatti and Gallese2011). ICMS of the anterior sector of the insula evokes a complex disgust-related behavior, characterized by a motor component (grimace of disgust) and a complex context-dependent behavior (refusal of food during stimulation). ICMS applied to a more posterior sector of the insula produces an affiliative behavior (lip-smacking).

Given the correlative nature of brain imaging, this approach hardly elucidates the possible causal role of a brain region in a specific emotional behavior. The choice of the authors to restrict their analysis only to neuroimaging, although done for practical reasons, weakens the result of their proposal. In fact, past electrophysiological studies showed that the stimulation of different emotion-related brain regions produces different behaviors related to specific emotions (for review, see Frijda Reference Frijda1986). It is not clear how a purely constructivist perspective could account for these data.

The locationist/constructionist debate could greatly benefit from overcoming the emotion experience/expression distinction, as has already happened in other fields of cognitive neuroscience, such as in the case of the perceptual experience of objects, space, and actions (see Gallese & Sinigaglia, in press). If a specific sensory pattern directly matches with a motor output (facial expression, visceromotor reaction), it makes sense to predict the existence of specific brain sensory-motor representations related to different emotional states. Is this locationist or constructivist?