Categorical judgments do not modify sensory representations in working memory

Categorical judgments can systematically bias the perceptual interpretation of stimulus features. However, it remained unclear whether categorical judgments directly modify working memory representations or, alternatively, generate these biases via an inference process down-stream from working memory. To address this question we ran two novel psychophysical experiments in which human subjects had to reverse their categorical judgments about a stimulus feature, if incorrect, before providing an estimate of the feature. If categorical judgments indeed directly altered sensory representations in working memory, subjects’ estimates should reflect some aspects of their initial (incorrect) categorical judgment in those trials. We found no traces of the initial categorical judgment. Rather, subjects seemed to be able to flexibly switch their categorical judgment if needed and use the correct corresponding categorical prior to properly perform feature inference. A cross-validated model comparison also revealed that feedback may lead to selective memory recall such that only memory samples that are consistent with the categorical judgment are accepted for the inference process. Our results suggest that categorical judgments do not modify sensory information in working memory but rather act as top-down expectations in the subsequent sensory recall and inference process.

LENGUAJE, FORMA INTERNA Y EXISTENCIA: LA FILOSOFÍA DEL LENGUAJE DE ANTON MARTY

El artículo analiza ciertos temas centrales de la filosofía del lenguaje de Anton Marty: primero, su teoría genética del origen casual del lenguaje; segundo, su descripción de los componentes mereológicos y semánticos del lenguaje, en particular del concepto de forma inter-na; tercero, su crítica del juicio categórico, basada en sus análisis de las oraciones impersonales y existenciales; cuarto, la importancia del concepto de existencia para aclarar problemas ontológicos. El trabajo hace además hincapié en señalar las conexiones entre su pensamiento y el de Edmund Husserl, ambos discípulos de Franz Brentano.The article addresses some essential issues of Anton Marty’s philosophy of language: first, its genetic theory of the random origin of language; second, his description of the mereological and the semantic components of language, focused on the concept of internal form; third, its criticism of the categorical judgment, based on its analyses of impersonal and existential sentences; fourth, the importance of the concept of existence in order shed light upon ontological problems. The paper also focuses on emphasizing the connections between his thought and that of Edmund Husserl, both disciples of Franz Brentano.

Dutch thetic and sentence-focus constructions on the semantics-pragmatics interface

This article studies the various uses of a Dutch thetic and sentence-focus construction, viz. the Syntactic Inversion with Filler Insertion Construction (henceforth: SIFIC), e.g. Er loopt een man over straat (‘There is a man walking across the street’). The article investigates whether theticity and sentence-focus are semantically encoded meanings of the SIFIC or pragmatically inferred senses. SIFIC tokens (N = 750) were extracted from the Dutch SoNaR Corpus and annotated for five factors. The analysis shows that the SIFIC can have information-structural uses that are diametrically opposed to theticity and sentence-focus, i.e. topic-comment structure, predicate-focus articulation and categorical judgment. It is argued that theticity and sentence-focus can therefore not be regarded as the encoded semantics of the SIFIC, but should rather be analyzed as default senses of the construction. Based on similar cross-linguistic findings the article takes issue with the assumption that most languages have dedicated thetic and sentence-focus constructions.

Categorical judgments do not modify sensory information in working memory

Categorical judgments can systematically bias the perceptual interpretation of stimulus features. However, it remained unclear whether categorical judgments directly modify working memory representations or, alternatively, generate these biases via an inference process down-stream from working memory. To address this question we ran two novel psychophysical experiments in which human subjects had to revert their categorical judgments about a stimulus feature, if incorrect based on feedback, before providing an estimate of the feature. If categorical judgments indeed directly altered sensory representations in working memory, subjects’ estimates should reflect some aspects of their initial (incorrect) categorical judgment in those trials.We found no traces of the initial categorical judgment. Rather, subjects seem to be able to flexibly switch their categorical judgment if needed and use the correct corresponding categorical prior to properly perform feature inference. A cross-validated model comparison also revealed that feedback may lead to selective memory recall such that only memory samples that are consistent with the categorical judgment are accepted for the inference process. Our results suggest that categorical judgments do not modify sensory information in working memory but rather act as top-down expectation in the subsequent sensory recall and inference process down-stream from working memory.

Colour Image Enhancement using Perceptual Saturation and Vividness

A perceptual study was conducted to enhance colour image quality in terms of naturalness and preference using perceptual scales of saturation and vividness. Saturation scale has been extensively used for this purpose while vividness has been little used. We used perceptual scales of a recently developed colour appearance model based on Jzazbz uniform colour space. A two-fold aim of the study was (i) to test performance of recently developed perceptual scales of saturation and vividness compared with previously used hypothetical models and (ii) to compare performance and chose one of saturation and vividness scales for colour image enhancement in future. Test images were first transformed to Jzazbz colour space and their saturation and vividness were then decreased or increased to obtain 6 different variants of the image. Categorical judgment method was used to judge preference and naturalness of different variants of the test images and results are reported.

Post-decision biases reveal a self-consistency principle in perceptual inference

Making a categorical judgment can systematically bias our subsequent perception of the world. We show that these biases are well explained by a self-consistent Bayesian observer whose perceptual inference process is causally conditioned on the preceding choice. We quantitatively validated the model and its key assumptions with a targeted set of three psychophysical experiments, focusing on a task sequence where subjects first had to make a categorical orientation judgment before estimating the actual orientation of a visual stimulus. Subjects exhibited a high degree of consistency between categorical judgment and estimate, which is difficult to reconcile with alternative models in the face of late, memory related noise. The observed bias patterns resemble the well-known changes in subjective preferences associated with cognitive dissonance, which suggests that the brain’s inference processes may be governed by a universal self-consistency constraint that avoids entertaining ‘dissonant’ interpretations of the evidence.

The Category of Substance

This paper considers a principal concept of metaphysics – the category of substance – as it figures in Kant’s critical program of establishing metaphysics as a science. Like Leibniz, Kant identifies metaphysical concepts through logical reflection on the form of cognitive activity. He thus begins with general logic’s account of categorical judgment as an act of subordinating predicate to subject. This categorical form is then considered in transcendental logic with reference to the possibility of its real use. Transcendental reflection reveals that the categorical form, in its potential for such use, constitutes the category of substance and accident, representing a first real subject and a determination of its existence. But to qualify for objective, scientific employment, metaphysics’ concepts must admit of real definitions, which show their objects to be possible, and such possibility, pace Leibniz, can be established only in relation to possible experience. Thus, relying on his doctrine of the schematism, Kant shows the category to figure constitutively in experience, as the ground of the first law of nature, that in all change substance persists.