Conscious Control Is Associated With Freezing of Mechanical Degrees of Freedom During Motor Learning

This study investigated whether conscious control is associated with freezing of mechanical degrees of freedom during motor learning. Participants practiced a throwing task using either error-strewn or error-reduced practice protocols, which encourage high or low levels of conscious control, respectively. After 24 hr, participants engaged in a series of delayed retention and transfer tests. Furthermore, propensity for conscious control was assessed using participants' ratings and freezing was gauged through movement variability of the throwing arm. Performance was defined by mean radial error. In the error-strewn group, propensity for conscious control was positively associated with both freezing and performance. In the error-reduced group, propensity for conscious control was negatively associated with performance, but not with freezing. These results suggest that conscious control is associated with freezing of mechanical degrees of freedom during motor learning.     

The relationship between pre-treatment clinical profile and treatment outcome in an integrated stuttering program

A procedure for subtyping individuals who stutter and its relationship to treatment outcome is explored. Twenty-five adult participants of the Comprehensive Stuttering Program (CSP) were classified according to: (1) stuttering severity and (2) severity of negative emotions and cognitions associated with their speech problem. Speech characteristics (percentage of stuttered syllables, distorted speech score, and the number of correctly produced syllables on a diadochokinesis task) and emotional/cognitive states (emotional reaction, speech satisfaction, and attitudes toward speaking) were assessed before and after treatment, and at a 1- and 2-year follow-up. The results showed that: (a) there was no relationship between stuttering severity and the severity of negative emotions and cognitions, (b) the severe stuttering group had the largest treatment gains but also the highest level of regression, and (c) at post-treatment and both follow-up assessments the differences on measures of emotions between the mild and severe emotional group had disappeared, chiefly due to a large decrease in the latter group's negative emotions and cognitions. Our findings show that, based on treatment gains, specific subgroups can be identified, each requiring different treatment approaches. This underlines the necessity of developing a better understanding of how various dimensions of stuttering relate to treatment outcome. Educational objectives: The reader will be able to: (1) describe why stuttering severity and negative emotions and cognitions that are related to stuttering should be investigated separately and (2) describe how treatment outcome relates to subtypes of persons who stutter.     

Idealness and similarity in goal-derived categories: A computational examination

The finding that the typicality gradient in goal-derived categories is mainly driven by ideals rather than by exemplar similarity has stood uncontested for nearly three decades. Due to the rather rigid earlier implementations of similarity, a key question has remained—that is, whether a more flexible approach to similarity would alter the conclusions. In the present study, we evaluated whether a similarity-based approach that allows for dimensional weighting could account for findings in goal-derived categories. To this end, we compared a computational model of exemplar similarity (the generalized context model; Nosofsky, Journal of Experimental Psychology. General 115:39–57, 1986) and a computational model of ideal representation (the ideal-dimension model; Voorspoels, Vanpaemel, & Storms, Psychonomic Bulletin & Review 18:1006-114, 2011) in their accounts of exemplar typicality in ten goal-derived categories. In terms of both goodness-of-fit and generalizability, we found strong evidence for an ideal approach in nearly all categories. We conclude that focusing on a limited set of features is necessary but not sufficient to account for the observed typicality gradient. A second aspect of ideal representations—that is, that extreme rather than common, central-tendency values drive typicality—seems to be crucial.     

Logic of artistic development: the case of Mondrian

In this article I show how we can give a formal representation and analysis of evolutions in artistic style, using the work of the painter Mondrian as an example. Capitalising on the idea that radical change in thought implies related changes in judgement criteria, we can in a “logic of development” specify the relations within, and between, those different sets of artistic judgement criteria that are considered typical of successive stages in artistic development. I discuss some of the problems involved in dealing with post-conventional thinking and judgement. Then I propose five major steps in Mondrian's artistic quest, showing how it is different—and how different it is—from other kinds of (e.g. moral or aesthetic) judgement development. Whereas many kinds of conceptual development lead to (various types of) criterion expansion, this form of entirely postconventional development goes in the opposite direction of a most stringent criterion reduction.     

Implicit short- and long-term memory direct our gaze in visual search

Visual attention is strongly affected by the past: both by recent experience and by long-term regularities in the environment that are encoded in and retrieved from memory. In visual search, intertrial repetition of targets causes speeded response times (short-term priming). Similarly, targets that are presented more often than others may facilitate search, even long after it is no longer present (long-term priming). In this study, we investigate whether such short-term priming and long-term priming depend on dissociable mechanisms. By recording eye movements while participants searched for one of two conjunction targets, we explored at what stages of visual search different forms of priming manifest. We found both long- and short- term priming effects. Long-term priming persisted long after the bias was present, and was again found even in participants who were unaware of a color bias. Short- and long-term priming affected the same stage of the task; both biased eye movements towards targets with the primed color, already starting with the first eye movement. Neither form of priming affected the response phase of a trial, but response repetition did. The results strongly suggest that both long- and short-term memory can implicitly modulate feedforward visual processing.     

An eye movement corpus study of the age-of-acquisition effect

In the present study, we investigated the effects of word-level age of acquisition (AoA) on natural reading. Previous studies, using multiple language modalities, showed that earlier-learned words are recognized, read, spoken, and responded to faster than words learned later in life. Until now, in visual word recognition the experimental materials were limited to single-word or sentence studies. We analyzed the data of the Ghent Eye-tracking Corpus (GECO; Cop, Dirix, Drieghe, & Duyck, in press), an eyetracking corpus of participants reading an entire novel, resulting in the first eye movement megastudy of AoA effects in natural reading. We found that the ages at which specific words were learned indeed influenced reading times, above other important (correlated) lexical variables, such as word frequency and length. Shorter fixations for earlier-learned words were consistently found throughout the reading process, in both early (single-fixation durations, first-fixation durations, gaze durations) and late (total reading times) measures. Implications for theoretical accounts of AoA effects and eye movements are discussed.     

Mapping the interplay among cognitive biases,emotion regulation,and depressive symptoms

Cognitive biases and emotion regulation (ER) difficulties have been instrumental in understanding hallmark features of depression. However, little is known about the interplay among these important risk factors to depression. This cross-sectional study investigated how multiple cognitive biases modulate the habitual use of ER processes and how ER habits subsequently regulate depressive symptoms. All participants first executed a computerised version of the scrambled sentences test (interpretation bias measure) while their eye movements were registered (attention bias measure) and then completed questionnaires assessing positive reappraisal, brooding, and depressive symptoms. Path and bootstrapping analyses supported both direct effects of cognitive biases on depressive symptoms and indirect effects via the use of brooding and via the use of reappraisal that was in turn related to the use of brooding. These findings help to formulate a better understanding of how cognitive biases and ER habits interact to maintain depressive symptoms.     

An antisymmetric psychometric function on a logarithmic scale

This very brief report introduces a psychometric function, very suitable for psychophysical data that displays Weber-like behaviour, because it is antisymmetric on a logarithmic scale.