Agnesa Pillon, PhD
Université catholique de Louvain (UCL)
Psychological Sciences Research Institute (IPSY)
Institute of Neuroscience (IoNS)
Fonds de la Recherche Scientifique - FNRS, Belgium 
 
 
   

Research Interests 

 
  • What is the content, structure and organization of concepts and words in our mind and brain?
  • How to examine, understand, and treat aphasic disorders (language disorders due to brain damage)?
 
 

Abstracts of recently published papers

  • Vannuscorps, G., Dricot, L. & Pillon, A. (2016). Persistent sparing of action conceptual processing in spite of increasing disorders of action production: A case against motor embodiment of action concepts. Cognitive Neuropsychology, 33, 191-219.

In this study, we addressed the issue of whether the brain sensorimotor circuitry that controls action production is causally involved in representing and processing action-related concepts. We examined the three-year pattern of evolution of brain atrophy, action production disorders, and action-related concept processing in a patient (J.R.) diagnosed with corticobasal degeneration. During the period of investigation, J.R. presented with increasing action production disorders resulting from increasing bilateral atrophy in cortical and subcortical regions involved in the sensorimotor control of actions (notably, the superior parietal cortex, the primary motor and premotor cortex, the inferior frontal gyrus, and the basal ganglia). In contrast, the patient’s performance in processing action-related concepts remained intact during the same period. This finding indicated that action concept processing hinges on cognitive and neural resources that are mostly distinct from those underlying the sensorimotor control of actions. Read the paper.


  • Vannuscorps, G., Andres, M. & Pillon, A. (2014). Is motor knowledge part and parcel of the concepts of manipulable artifacts? Clues from a case of upper limb aplasia. Brain and Cognition, 84, 132-140.
The sensory-motor theory of conceptual representations assumes that motor knowledge of how an artifact is manipulated is constitutive of its conceptual representation. Accordingly, if we assume that the richer the conceptual representation of an object is, the easier that object is identified, manipulable artifacts that are associated with motor knowledge should be identified more accurately and/or faster than manipulable artifacts that are not (everything else being equal). In this study, we tested this prediction by investigating the identification of manipulable artifacts in an individual, DC, who was totally deprived of hand motor experience due to upper limb aplasia. This condition prevents him from interacting with most manipulable artifacts, for which he thus has no motor knowledge at all. However, he had motor knowledge for some of them, which he routinely uses with his feet. We contrasted DC’s performance in a timed picture naming task for manipulable artifacts for which he had motor knowledge versus those for which he had no motor knowledge. No detectable advantage on DC’s naming performance was found for artifacts for which he had motor knowledge compared to those for which he did not.  This finding suggests that motor knowledge is not part of the concepts of manipulable artifacts.  Read the paper
  
 
  • Vannuscorps, G., Andres, M. & Pillon, A. (2013). When does action comprehension need motor involvement ? Evidence from upper limb aplasia. Cognitive Neuropsychology, 30, 253-283. 
Motor theories of action comprehension claim that comprehending the meaning of an action performed by a conspecific relies on the perceiver’s own motor representation of the same action. According to this view, whether an action belongs to the motor repertoire of the perceiver should impact the ease by which this action is comprehended. We tested this prediction by assessing the ability of an individual (DC) born without upper limbs to comprehend actions involving hands (e.g., throwing) or other body parts (e.g., jumping). The tests used a range of different visual stimuli differing in the kind of information provided. The results showed that DC was as accurate and fast as control participants in comprehending natural video and photographic presentations of both manual and non-manual actions, as well as pantomimes. However, he was selectively impaired at identifying point-light animations of manual actions. This impairment was not due to a difficulty in processing kinematic information per se. DC was indeed as accurate as control participants in two additional tests requiring a fine-grained analysis of an actor’s arm or whole-body movements. These results challenge motor theories of action comprehension by showing that the visual analysis of body shape and motion provides sufficient input for comprehending observed actions. However, when body shape information is sparsely available, motor involvement becomes critical to interpret observed actions. We suggest that, with natural human movement stimuli, motor representations contribute to action comprehension each time visual information is incomplete or ambiguous.. Read the paper 
 
 
  • Palma-Duran, C. & Pillon, A. (2011). The role of grammatical category information in spoken word retrieval. Frontiers in Psychology, 2: article 338.
We investigated the role of lexical syntactic information such as grammatical gender and category in spoken word retrieval processes by using a blocking paradigm in picture and written word naming experiments. In Experiments 1, 3, and 4, we found that the naming of target words (nouns) from pictures or written words was faster when these target words were named within a list where only words from the same grammatical category had to be produced (homogeneous category list: all nouns) than when they had to be produced within a list comprising also words from another grammatical category (heterogeneous category list: nouns and verbs). On the other hand, we detected no significant facilitation effect when the target words had to be named within a homogeneous gender list (all masculine nouns) compared to a heterogeneous gender list (both masculine and feminine nouns). In Experiment 2, using the same blocking paradigm by manipulating the semantic category of the items, we found that naming latencies were significantly slower in the semantic category homogeneous in comparison with the semantic category heterogeneous condition. Thus semantic category homogeneity caused an interference, not a facilitation effect like grammatical category homogeneity. Finally, in Experiment 5, nouns in the heterogeneous category condition had to be named just after a verb (category-switching position) or a noun (same-category position). We found a facilitation effect of category homogeneity but no significant effect of position, which showed that the effect of category homogeneity found in Experiments 1, 3, and 4 was not due to a cost of switching between grammatical categories in the heterogeneous grammatical category list. These findings supported the hypothesis that grammatical category information impacts word retrieval processes in speech production, even when words are to be produced in isolation. They are discussed within the context of extant theories of lexical production. Read the paper

 
  • Pillon, A., & d'Honincthun, P. (2011). A common processing system for the concepts of artifacts and actions? Evidence from a case of a disproportionate conceptual impairment for living things. Cognitive Neuropsychology, 28, 1-43.
We report the results of a single-case study carried out with a brain-damaged patient, G.C., whose conceptual knowledge of living things (animals and plants) was significantly more impaired than his knowledge of artifacts and his knowledge of actions, which were similarly impaired. We examined whether this pattern of conceptual impairment could be accounted for by the “sensory/functional” or the “manipulability” account for category-specific conceptual impairments advocated within the feature-based organization theory. To this end, we assessed, first, the patient’s knowledge of sensory compared to functional and motor features and, second, his knowledge of nonmanipulable compared to manipulable items. The findings showed that the patient’s disproportionate impairment for living things compared to both artifacts and actions was not associated with a disproportionate impairment of sensory compared to functional or motor knowledge or with a relative sparing of manipulable compared to nonmanipulable items. We then discuss how alternative theories of conceptual knowledge organization could account for G.C.’s pattern of category-specific deficit. Read the paper
 
 
  • Léonard, B., de Partz, M.-P., Grandin, C.& Pillon, A. (2009). Domain-specific reorganization of semantic processing after extensive damage to the left temporal lobe. NeuroImage, 45, 572‑586.
We investigated with fMRI the cortical correlates of recovery of semantic processing in a patient (DL) with left temporal damage. Names of animals, plant, and artifacts (semantic conditions) and reversed words (baseline condition) were auditorily presented to the patient and nine control subjects in a category monitoring task. Data analyses showed large  differences between the patterns of domain-specific semantic activation observed in DL and the control subjects, which could be attributed to a cortical reorganization compensating for the damaged part of the semantic processing system in DL. Such reorganization relied on three main mechanisms, first, upholding of a subset of the structurally intact domain-specific regions, second, functional changes (both decreases and increases) of the domain specificity in several structurally intact regions that are normally engaged in the domain-specific network and, third, recruitment of supplementary domain-specific areas. Thus, in DL, animal-specific processing engaged supplementary areas in the left lingual gyrus and right cuneus, which correspond to animal-specific regions usually engaged in more demanding semantic tasks whereas the supplementary areas recruited for artifact-specific processing within the left superior/middle occipital lobe and right angular gyrus probably are endowed with a related but not domain-specific, semantic function. In contrast, no supplementary area contributed to plant-specific processing in DL. These findings suggest that the pattern of cortical reorganization consecutive to damage to the semantic processing network depends on the particular domain-specific function sustained by the damaged areas and the capacity of the remaining areas to assume this function. Read the paper