The masked priming toolbox: an open-source MATLAB toolbox for masked priming researchers

The Masked Priming Toolbox is an open-source collection of MATLAB functions that utilizes the free third-party PsychToolbox-3 (PTB3: Brainard, Spatial Vision, 10, 433-436, 1997; Kleiner, Brainard & Pelli, Perception, 36, 2007; Pelli, Spatial Vision, 10, 437-442, 1997). It is designed to allow a researcher to run masked (and unmasked) priming experiments using a variety of response devices (including keyboards, graphics tablets and force transducers). Very little knowledge of MATLAB is required; experiments are generated by creating a text file with the required parameters, and raw and analyzed data are output to Excel (as well as MATLAB) files for further analysis. The toolbox implements a variety of stimuli for use as primes and targets, as well as a variety of masks. Timing, size, location, and orientation of stimuli are all parameterizable. The code is open-source and made available on the Web under a Creative Commons License.     

Visual categorization of natural stimuli by domestic dogs

One of the fundamental issues in the study of animal cognition concerns categorization. Although domestic dogs (Canis familiaris) are on the brink to become one of the model animals in animal psychology, their categorization abilities are unknown. This is probably largely due to the absence of an adequate method for testing dogs’ ability to discriminate between large sets of pictures in the absence of human cueing. Here we present a computer-automated touch-screen testing procedure, which enabled us to test visual discrimination in dogs while social cueing was ruled out. Using a simultaneous discrimination procedure, we first trained dogs (N = 4) to differentiate between a set of dog pictures (N = 40) and an equally large set of landscape pictures. All subjects learned to discriminate between the two sets and showed successful transfer to novel pictures. Interestingly, presentation of pictures providing contradictive information (novel dog pictures mounted on familiar landscape pictures) did not disrupt performance, which suggests that the dogs made use of a category-based response rule with classification being coupled to category-relevant features (of the dog) rather than to item-specific features (of the background). We conclude that dogs are able to classify photographs of natural stimuli by means of a perceptual response rule using a newly established touch-screen procedure. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Chunking processes in the learning of event sequences: Electrophysiological indicators

The present study investigated whether effects of implicit learning (IL) are due to well-learned and explicitly represented parts of the stimulus material ("chunks"). To this purpose, event-related brain potentials (ERPs) were recorded during an oddball-version of a serial reaction time (RT) task: At unpredictable positions within a 16-item letter sequence, single deviant items replaced an item of the repeatedly presented standard sequence. After acquisition, the "process dissociation procedure" (Jacoby, 1991) was adopted to identify explicitly learned sequence parts for each participant. Acquisition of sequence knowledge was reflected in faster RTs for standard items than for deviant items and in enhanced N2b and P3b components for deviant items. While the ERP effects were obtained for explicitly represented sequence parts only, RT effects were independent of subsequent reproduction performance. These results indicated that (1) ERPs are a valid measure of explicit knowledge, (2) implicit and explicit knowledge coexist in serial RT tasks, and (3) chunking processes play a major role in the acquisition of explicit knowledge about event sequences.     

Active masks and active inhibition: a comment on Lleras and Enns (2004) and on Verleger, Jaskowski, Aydemir, van der Lubbe, and Groen (2004)

Verleger, Jaskowski, Aydemir, van der Lubbe, and Groen and Lleras and Enns have argued that negative compatibility effects (NCEs) obtained with masked primes do not reflect self-inhibition processes in motor control. Instead, NCEs are assumed to reflect activation of the response opposite to the prime, triggered by the presence of prime/targetlike features in the mask. Thus, no NCEs should be elicited when masks do not contain such task-relevant features. In Experiments 1 and 3, the authors demonstrate that NCEs can be obtained when masks contain only irrelevant features. Experiment 2 demonstrates that positive compatibility effects (PCEs) will occur with such masks when masked primes are presented peripherally. These results are inconsistent with the mask-induced activation accounts but are in line with the self-inhibition hypothesis of the NCE. Although perceptual interactions and mask-induced motor activations may contribute to NCEs under certain conditions, they cannot provide a full explanation for these effects.     

Mother knows best: effects of maternal modelling on the acquisition of fear and avoidance behaviour in toddlers

The present study was conducted to investigate the influence of parental modelling on the acquisition of fear and avoidance towards novel, fear-relevant stimuli in a sample of 30 toddlers. The toddlers were shown a rubber snake and spider, which were alternately paired with either negative or positive facial expressions by their mothers. Both stimuli were presented again after a 1- and a 10-min delay, while mothers maintained a neutral expression. The children showed greater fear expressions and avoidance of the stimuli following negative reactions from their mothers. This was true for both genders although the degree of modelled avoidance was greater in girls than in boys. The strong observational learning results are consistent with views that modelling constitutes a mechanism by which fear may be acquired early in life.     

On Kant's Conception of Inner Sense: Self‐Affection by the Understanding

Among the extensive literature on the first Critique, very few commentators offer a thorough analysis of Kant's conception of inner sense. This is quite surprising since the notion is central to Kant's theoretical philosophy, and it is very difficult to provide a consistent interpretation of this notion. In this paper, I first summarize Kant's claims about inner sense in the Transcendental Aesthetic and show why existing interpretations have been unable to dissolve the tensions arising from the conjunction of these claims. Secondly, I present my own reconstruction of Kant's model of inner sense, relying essentially on Kantian considerations found in the B‐version of the Transcendental Deduction. My main idea is that inner sense, for Kant, is a passive faculty that gets affected by the understanding performing its figurative synthesis on material given in outer sense. In the remainder of the paper, I highlight a few consequences of my interpretation and outline ways to deal with some objections.     

Two kinds of first-person-oriented content

In this paper, I will argue that two kinds of first-person-oriented content are distinguished in more ways than usually thought and I propose an account that will shed new light on the distinction. The first kind consists of contents of attitudes de se (in a broad sense); the second kind consists of contents that give rise to intuitions of relative truth. I will present new data concerning the two kinds of first-person-oriented content, together with a novel account of propositional content in general, namely based on the notion of an attitudinal object. That notion solves two major problems with Lewis’s account of contents of attitudes de se and clarifies the difference between contents of attitudes de se and contents that give rise to intuitions of relative truth. I will propose an analysis of contents of the second kind in terms of what I call first-person-based genericity, a form of genericity most explicitly expressed by sentences with generic one. I show how the overall account explains the particular semantic properties of sentences giving rise to intuitions of relative truth that distinguish them from sentences with expressions interpreted de se. I will start by introducing Lewis’s account of attitudes de se and the problems that go along with that account. Introducing the notion of an attitudinal object, I will extend the account by an account of the truth conditions of the content of attitudes de se. I then discuss the second kind of first-person-oriented content, which is associated with intuitions of relative truth, and give an account of such contents on the basis of an analysis of generic one. Again making use of attitudinal objects, I will make clear what exactly distinguishes those contents from first-person-oriented contents of the first sort.