Manipulability and object recognition: is manipulability a semantic feature?
Several lines of evidence exist, coming from neuropsychology, neuroimaging and behavioural investigations on healthy subjects, suggesting that an interaction might exist between the systems devoted to object identification and those devoted to online object-directed actions and that the way an object is acted upon (manipulability) might indeed influence object recognition. In this series of experiments on speeded word-to-picture-matching tasks, it is shown how the presentation of pairs of objects sharing similar manipulation causes greater interference with respect to objects sharing only visual similarity (experiment 1). Moreover, (experiment 2) it is shown how the repeated presentation of pairs of objects sharing a similar type of manipulation leads to a 'negative' serial position effect, with the number of errors increasing across presentations, a behaviour that is typically found in patients with access deficits to semantic representations. By contrast, the repeated presentation of pairs of objects sharing only visual similarity leads to an opposite 'positive' serial position effect, with errors decreasing across presentations. It is argued that a negative serial position effect is linked to interference occurring within the semantic system, and therefore that the way an object is manipulated is indeed a semantic feature, critical in defining manipulable object properties at a semantic level. To our knowledge, this constitutes the first direct evidence of manipulability being a semantic dimension. The results are discussed in the light of current models of semantic memory organization.
Cognitive Neuroscience Sector, International School for Advanced Studies SISSA-ISAS, via Bonomea 265, 34136 Trieste, Italy. fabio.campanella@uniud.it
Fabio
F
Campanella
Tim
T
Shallice
D000328:Adult; D032763:Behavior Control / Q000379:methods* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology*; D012660:Semantics; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult