To bring clarity to the data of experience and reduce environmental complexity, we make use of mental processes that can register the information we receive from outside, within organized constructs. These constructs, categories, serve the valuable function of guiding our behavior, enabling us to categorize new information based on what we have already acquired and to integrate new knowledge with what we have encountered and processed in the past, thus making interactions with the world easier. Categorization is, therefore, that complex cognitive phenomenon in which both processes of acquiring and using knowledge come into play.

In our lab, we studied how the information available during the categorization process is used when adopting an analytical mode of representation, that is, one that considers individual features separately, or a holistic one, which instead represents examples as a whole. We have studied analytic and holistic categorization modes by introducing a paradigm in which biased examples (in which irrelevant features are made salient) are presented at first and then gradually eliminated.

In this study, we introduced a new experimental paradigm, called Active Feature Composition, which replaces the traditional classification task with a task in which one is required to actively "construct" the examples to be tested by combining their features. This is a production task, in which participants do not have to classify new exemplars but are actively involved in producing items that they believe belong to the learned categories. The procedure is as follows: at the end of the training, after observing a set of particular instances of one or more categories, participants are asked to select features from a set containing all possible dimensions of the features of the learned categories, to combine them together to obtain the complete example. Once the combination is complete, each example is to be assigned a categorical label, thus indicating the category to which it belongs.                        
 

Greco A., Moretti S. (2017) Use of evidence in a categorization task: analytic and holistic processing modes. Cognitive Processing, 18, 4, 431-446. DOI: 10.1007/s10339-017-0829-2

A. Greco, C. Caneva, From actions to symbols and back: are there action symbol systems (PDF file). InProceedings of XXVII Annual Conference of the Cognitive Science Society, July 21-23, Stresa, 2005.

This line of research is pursued in our Lab with several aims. The most important investigations are aimed at studying:

1) how verbal descriptions of situations, expressing different properties and relations, are converted into pictorial representations

2) the effectiveness of diagrams in education and other communication and problem solving fields

3) how diagrammatic instructions for assembling objects are created and used

The classical computational conception of meaning has been challenged by the idea that symbols must be grounded on sensorimotor processes. A difficult question arises from the fact that grounding representations (GREPs) cannot be symbolic themselves but, in order to support compositionality, should work as primitives. This implies that they should be precisely identifiable and strictly connected with discriminable perceptual features. Ideally, each representation should correspond to a single discriminable feature.

The present study was aimed at exploring whether feature discrimination is a fundamental requisite for grounding compositional symbols. We studied this problem by using Integral stimuli, composed of two interacting and not separable features. Such stimuli were selected in Experiment1 as pictures whose component features are easily or barely discriminable (Separable or Integral) on the basis of psychological distance metrics (City-block or Euclidean) computed from similarity judgments. In Experiment 2, either each feature was associated with one word of a two-word expression, or the whole stimulus with a single word. In Experiment 3 the procedure was reversed and words or expressions were associated with whole pictures or separate features.

Results support the hypothesis that single words are best grounded by Integral stimuli and composite expressions by Separable stimuli, where a strict association of single words with discriminated features is possible.

Filippo Domaneschi (Department of Philosophy – University of Genoa)

Presupposition is a widely discussed topic in the analytic tradition since the beginning: Frege, in Über Sinn und Bedeutung claims that the use of a singular term presupposes the existence of the individual denoted. Since this Fregean stance, analytic scholars have given the following definition: a sentence p semantically presupposes a sentence q if we need the truth of q in order to treat p as endowed with sense, that is either as true or as false. Only in the fifties ordinary language philosophy recovered a new concept of presupposition. Starting with Strawson and especially with Austin the concept of presupposition is linked no more on necessary conditions for truth conditional evaluation of a sentence, but as a necessary condition for the felicity or correctness of a speech act.

With Stalnaker analytic philosophy abandoned the notion of semantic presupposition to treat presupposition as a propositional attitude. The focus of the theory passes from the semantic level of sentences to the pragmatic level of utterances, therefore including the ‘cognitive context’ of the speakers background of beliefs. In Stalnaker’s view the common ground of a conversation at a particular time is the set of propositions that participants in that conversation at that time mutually believe as accepted as true and that, for that reason, they take for granted. Hence, an assertion of a sentence p is appropriate only if at the time t the common ground includes the presupposition q required by p, namely q is believed as accepted as true by the speakers. According to Gauker, Stalnaker’s cognitive account is not satisfactory in order to explain the phenomenon of presupposition. He claims that presuppositions cannot be defined in terms of speakers beliefs on the common ground. Rather, it should be taken into account what he calls the ‘objective context’, that is the set of objectively relevant propositional elements – the propositional context – that speakers ought to share in order to evaluate the appropriateness of utterances so as to reach the goal of a conversation.

The main topics of this research are the following:

(i) to give a systematic analysis of problems and terminology of the recent literature on presupposition.

(ii) to compare and provide an evaluation of the cognitive and the objective account of presuppositions.

(iii) to develop an original definition for the notion of ‘context’ that is able to face the objections connected with the received accounts.

(iv) to build a theoretical assessment of the number of ways in which speakers may take for granted a presupposition (that is an unsolved problem in the contemporary debate).

(v) to explore the relation between the ground of presupposition and the notion of ‘goal of a conversation’.

(vi) finally, we aim to work out some tests on cognitive reactions on the role of presupposition in discourse understanding, in order to verify the psychological plausibility of the claims given in (iii) and (iv) and to verify possible alternatives.

According to two of the main current approaches to categorization, categories might be constructed either by abstraction of defining features (Smith, Shoben, & Rips, 1974), or by comparison of new cases with previousexamples (Brooks, 1978; Nosofsky, 1986). According to a new trend in literature such approaches may be considered as not necessarily in contradiction, and various possibilities have been explored that attenuate the differences between them (e.g. Erickson M.A., Kruschke J.K., 1998).