We are what we eat: How food is represented in our mind/brain

Despite the essential role of food in our lives, we have little understanding of the way our knowledge about food is organized in the brain. At birth, human infants exhibit very few food preferences, and do not yet know much about what is edible and what is not. A multisensory learning development will eventually turn young infants into omnivore adults, for whom deciding what to eat becomes an effortful task. Recognizing food constitutes an essential step in this decisional process. In this paper we examine how concepts about food are represented in the human brain. More specifically, we first analyze how brain-damaged patients recognize natural and manufactured food, and then examine these patterns in the light of the sensory-functional hypothesis and the domain-specific hypothesis. Secondly, we discuss how concepts of food are represented depending on whether we embrace the embodied view or the disembodied view. We conclude that research on food recognition and on the organization of knowledge about food must also take into account some aspects specific to food category, the relevance of which has not been sufficiently recognized and investigated to date.     

The attribution of intentionality: the role of skill and morality

The present study contributes to the discussion on the different components which constitute the intentionality concept about an undesired side effect, focusing on the morality and the skill. Two hundred and forty participants were asked to read a brief story about a car accident, in which it was explained the motivation of the high speed and objective and subjective skill of the agent to drive the car, and to fill in six questions about intentionality, objective risk, mental representation of risk, risk acceptance and blameworthiness for the outcome. The principal results showed that when the motivation is morally negative, people judge the side effect more intentional, also because they make more severe judgments about risk and blameworthiness. Moreover, when people are objectively proficient to perform the action (objective skill) the side effect is considered less risky and intentional and, in the case of a negative outcome, they are judged less severely than if they have a poor ability. Finally, a self-assessment of low skill to make the action (subjective skill) leads people to assess higher risks and, consequently, more intentionality for the side effect. The results are discussed on the basis of the literature about some specific components that make up the intentionality concept.     

PRINZ'S PROBLEMATIC PROXYTYPES

Jesse Prinz has argued that a proxy type theory of concepts provides what he calls the 'intentionality' and 'cognitive content' desiderata better than any current competitor, and that the hybrid nature of proxytypes allows his theory to combine the informational component of informational atomism with the view that concepts are semantically structured entities. In response, I argue that the hybrid character of proxytypes, far from delivering the advantages Prinz claims, generates a threatening dilemma: either his theory is novel but fails to deliver the intentionality and cognitive content desiderata, or it delivers these desiderata but is not novel.     

Representational neglect for words as revealed by bisection tasks

In the present study, we showed that a representational disorder for words can dissociate from both representational neglect for objects and neglect dyslexia. This study involved 14 brain-damaged patients with left unilateral spatial neglect and a group of normal subjects. Patients were divided into four groups based on presence of left neglect dyslexia and representational neglect for non-verbal material, as evaluated by the Clock Drawing test. The patients were presented with bisection tasks for words and lines. The word bisection tasks (with words of five and seven letters) comprised the following: (1) representational bisection: the experimenter pronounced a word and then asked the patient to name the letter in the middle position; (2) visual bisection: same as (1) with stimuli presented visually; and (3) motor bisection: the patient was asked to cross out the letter in the middle position. The standard line bisection task was presented using lines of different length. Consistent with the literature, long lines were bisected to the right and short lines, rendered comparable in length to the words of the word bisection test, deviated to the left (crossover effect). Both patients and controls showed the same leftward bias on words in the visual and motor bisection conditions. A significant difference emerged between the groups only in the case of the representational bisection task, whereas the group exhibiting neglect dyslexia associated with representational neglect for objects showed a significant rightward bias, while the other three patient groups and the controls showed a leftward bisection bias. Neither the presence of neglect alone nor the presence of visual neglect dyslexia was sufficient to produce a specific disorder in mental imagery. These results demonstrate a specific representational neglect for words independent of both representational neglect and neglect dyslexia.     

Imitation of transitive and intransitive actions in healthy individuals

A handful of patients have been described as being impaired in performing transitive gestures, despite being still able to perform intransitive gestures. This impairment need not be explained by assuming different mechanisms; rather, it can be due to transitive actions being more difficult. In this study we tested whether neurologically healthy participants had greater difficulties in imitating transitive actions with respect to intransitive actions. Consistent with the prediction, subjects imitated intransitive better than transitive gestures. The ease of imitation of intransitive actions supports the complexity account of apraxic impairments.     

Alignment effect: primary-secondary learning and cognitive styles

The degree to which the way of learning spatial information (primary/secondary learning) and spatial cognitive style (landmark/route/survey) affect orientation specificity (alignment effect) is studied. We think that the most important factor explaining the absence of the alignment effect is the spatial cognitive style. We hypothesise that while landmark participants show an alignment effect after both primary and secondary learning, route participants show this effect only after secondary learning, and survey participants do not show it at all. Participants performed three tasks in order to distinguish their cognitive style; they were then randomly assigned to primary or secondary learning and submitted to directional judgment tasks to verify whether the alignment effect was present. The results confirm our hypothesis.     

The strategic control of multiple routes in imitation of actions

The aim of this study was to bring to the surface the strategic use of imitative processes in the context of a 2-route model: (a) direct imitation, used in reproducing new, meaningless actions, and (b) imitation based on stored semantic knowledge of familiar meaningful actions. Three experiments were carried out with healthy participants who reproduced meaningful and meaningless actions within an established time limit. The study investigated 3 factors that could potentially affect the selection of processes used for imitation: (a) the composition of the experimental list (blocked or mixed presentation), (b) the presence-absence of instructions (Experiments 1 and 2), and (c) the relative proportions of the stimuli (Experiment 3). Overall, the results suggest that each of these factors influences the selection of imitative strategies in healthy individuals with temporarily reduced capacities, as happens in the case of brain-damaged patients.     

Preserved fronto-striatal plasticity and enhanced procedural learning in a transgenic mouse model of Alzheimer's disease overexpressing mutant hAPPswe

Mutations in the amyloid precursor protein (APP) gene inducing abnormal processing and deposition of beta-amyloid protein in the brain have been implicated in the pathogenesis of Alzheimer's disease (AD). Although Tg2576 mice with the Swedish mutation (hAPPswe) exhibit age-related Abeta-plaque formation in brain regions like the hippocampus, the amygdala, and the cortex, these mice show a rather specific deficit in hippocampal-dependent learning and memory tasks. In view of recent findings showing that neural systems subserving different forms of learning are not simply independent but that depressing or enhancing one system affects learning in another system, we decided to investigate fronto-striatal synaptic plasticity and related procedural learning in these mutants. Fronto-striatal long-term depression (LTD) induced by tetanic stimulation of the cortico-striatal input was similar in Tg2576 and wild-type control mice. Behavioral data, however, pointed to an enhancement of procedural learning in the mutants that showed robust motor-based learning in the cross maze and higher active avoidance scores. Thus, in this mouse model of AD, an intact striatal function associated with an impaired hippocampal function seems to provide neural conditions favorable to procedural learning. Our results suggest that focusing on preserved or enhanced forms of learning in AD patients might be of interest to describe the functional reorganization of the brain when one memory system is selectively compromised by neurological disease.