Exploring the dynamics of design fluency in children with and without ADHD using artificial neural networks

The neuropsychology of attention deficit/hyperactivity disorder (ADHD) has been extensively studied, with a general focus on global performance measures of executive function. In this study, we compared how global (i.e., endpoint) versus process (i.e., dynamic) measures of performance may help characterize children with and without ADHD using a design fluency task as a case study. The secondary goal was to compare the sensitivity of standard versus connectionist statistical models to group differences in cognitive data. Thirty-four children diagnosed with ADHD and 37 children without ADHD aged 8–11 years old were tested on the Five-Point Test. The continuous process measure of performance, indexed as the number of produced designs at each consecutive 1 minute interval during 5 minutes, was analyzed against the discrete process measure, that is, the number of designs between first and last intervals and the standard global performance measure of total number of produced designs. Results show that the continuous process measure distinguished the two groups better than the two other measures. The detailed observation of production patterns revealed a decreasing linear trajectory in children without ADHD that contrasts with the flat, but fluctuating productivity pattern of children with ADHD. With regards to the second goal, results show that the connectionist and standard methods are equally sensitive to group differences for the three types of measures. This illustrates the utility of quantitative process measures together with the connectionist method in neuropsychological research and suggests great potential for a dynamical approach to cognition.     

Predictive Factors of Spiritual Quality of Life during the COVID-19 Pandemic: A Multivariate Analysis

Journal of Religion and Health - COVID-19 has led to the implementation of various social and sanitary measures, impacting populations’ quality of life. Aims: Documenting the spiritual...     

How category learning affects object representations: not all morphspaces stretch alike

How does learning to categorize objects affect how people visually perceive them? Behavioral, neurophysiological, and neuroimaging studies have tested the degree to which category learning influences object representations, with conflicting results. Some studies have found that objects become more visually discriminable along dimensions relevant to previously learned categories, while others have found no such effect. One critical factor we explore here lies in the structure of the morphspaces used in different studies. Studies finding no increase in discriminability often use blended morphspaces, with morphparents lying at corners of the space. By contrast, studies finding increases in discriminability use factorial morphspaces, defined by separate morphlines forming axes of the space. Using the same 4 morphparents, we created both factorial and blended morphspaces matched in pairwise discriminability. Category learning caused a selective increase in discriminability along the relevant dimension of the factorial space, but not in the blended space, and led to the creation of functional dimensions in the factorial space, but not in the blended space. These findings demonstrate that not all morphspaces stretch alike: Only some morphspaces support enhanced discriminability to relevant object dimensions following category learning. Our results have important implications for interpreting neuroimaging studies reporting little or no effect of category learning on object representations in the visual system: Those studies may have been limited by their use of blended morphspaces.     

An analysis of letter expertise in a levels-of-categorization framework

While there has been increasing effort in dissociating the neural substrates recruited by perception of different objects, the theoretical and behavioural work needed to understand such dissociation lags behind. In an attempt to compare expertise in letter and face perception, we outline a theoretical framework that characterizes different types of object expertise based on the task demand (level of abstraction) required in object categorization. Face perception requires categorization at a subordinate level, whereas letter perception involves mainly basic-level categorization. Accordingly face and letter perception should represent two different types of expertise and display different neural and behavioural markers. Results from three behavioural experiments supported the predictions of the framework in that letter expertise is characterized by an enhancement of the basic-level advantage, instead of its attenuation as typically found for face perception. We compare this framework with Farah's taxonomy of visual abilities based on cooccurrence of deficits in visual agnosias.     

Holistic processing predicts face recognition

The concept of holistic processing is a cornerstone of face-recognition research. In the study reported here, we demonstrated that holistic processing predicts face-recognition abilities on the Cambridge Face Memory Test and on a perceptual face-identification task. Our findings validate a large body of work that relies on the assumption that holistic processing is related to face recognition. These findings also reconcile the study of face recognition with the perceptual-expertise work it inspired; such work links holistic processing of objects with people's ability to individuate them. Our results differ from those of a recent study showing no link between holistic processing and face recognition. This discrepancy can be attributed to the use in prior research of a popular but flawed measure of holistic processing. Our findings salvage the central role of holistic processing in face recognition and cast doubt on a subset of the face-perception literature that relies on a problematic measure of holistic processing.     

Expertise increases the functional overlap between face and object perception

Recent studies indicate that expertise with objects can interfere with face processing. Although competition occurs between faces and objects of expertise, it remains unclear whether this reflects an expertise-specific bottleneck or the fact that objects of expertise grab attention and thereby consume more central resources. We investigated the perceptual costs of expertise by measuring visual thresholds for identifying targets embedded within RSVP sequences presented at varying temporal rates. Car experts and novices searched for face targets among face and car distractors, or watch targets among watch and car distractors. Remarkably, car experts were slower than novices at identifying faces among task-irrelevant cars, yet faster than novices at identifying watches among cars. This suggests that car expertise leads to greater functional overlap between cars and faces while reducing the functional overlap between cars and objects, a result incompatible with the notion of an encapsulated module for exclusive processing of faces.     

Why does selective attention to parts fail in face processing?

One hallmark of holistic face processing is an inability to selectively attend to 1 face part while ignoring information in another part. In 3 sequential matching experiments, the authors tested perceptual and decisional accounts of holistic processing by measuring congruency effects between cued and uncued composite face halves shown in spatially aligned or disjointed configurations. The authors found congruency effects when the top and bottom halves of the study face were spatially aligned, misaligned (Experiment 1), or adjacent to one another (Experiment 2). However, at test, congruency effects were reduced by misalignment and abolished for adjacent configurations. This suggests that manipulations at test are more influential than manipulations at study, consistent with a decisional account of holistic processing. When encoding demands for study and test faces were equated (Experiment 3), the authors observed effects of study configuration suggesting that, consistent with a perceptual explanation, encoding does influence the magnitude of holistic processing. Together, these results cannot be accounted for by current perceptual or decisional accounts of holistic processing and suggest the existence of an attention-dependent mechanism that can integrate spatially separated face parts.     

Object detection and basic-level categorization: Sometimes you know it is there before you know what it is

A tight temporal coupling between object detection (is an object there?) and object categorization (what kind of object is it?) has recently been reported (Grill-Spector &; Kanwisher, 2005), suggesting that image segmentation into different objects and categorization of those objects at the basic level may be the very same mechanism. In the present work, we decoupled the time course of detection and categorization through two task manipulations. First, inverted objects were categorized significantly less accurately than upright objects across a range of image presentation durations, but no significant effect on object detection was observed. Second, systematically degrading stimuli affected categorization significantly more than object detection. The time course of object detection and object categorization can be selectively manipulated. They are not intrinsically linked. As soon as you know an object is there, you do not necessarily know what it is.     

Context influences holistic processing of nonface objects in the composite task

We explored whether holistic-like effects can be observed for nonface objects in novices as a result of the task context. We measured contextually induced congruency effects for novel objects (Greebles) in a sequential matching selective attention task (composite task). When format at study was blocked, congruency effects were observed for study-misaligned, but not study-aligned, conditions (Experiment 1). However, congruency effects were observed in all conditions when study formats were randomized (Experiment 2), revealing that the presence of certain trial types (study-misaligned) in an experiment can induce congruency effects. In a dual task, a congruency effect for Greebles was induced in trials in which a face was first encoded, but only when it was aligned (Experiment 3). Thus, congruency effects can be induced by context that operates at the scale of the entire experiment or within a single trial. Implications for using the composite task to measure holistic processing are discussed.