What aspects of face processing are impaired in developmental prosopagnosia?

Developmental prosopagnosia (DP) is a severe impairment in identifying faces that is present from early in life and that occurs despite no apparent brain damage and intact visual and intellectual function. Here, we investigated what aspects of face processing are impaired/spared in developmental prosopagnosia by examining a relatively large group of individuals with DP (n = 8) using an extensive battery of well-established tasks. The tasks included measures of sensitivity to global motion and to global form, detection that a stimulus is a face, determination of its sex, holistic face processing, processing of face identity based on features, contour, and the spacing of features, and judgments of attractiveness. The DP cases showed normal sensitivity to global motion and global form and performed normally on our tests of face detection and holistic processing. On the other tasks, many DP cases were impaired but there was no systematic pattern. At least half showed deficits in processing of facial identity based on either the outer contour or spacing of the internal features, and/or on judgments of attractiveness. Three of the eight were impaired in processing facial identify based on the shape of internal features. The results show that DP is a heterogeneous condition and that impairment in recognizing faces cannot be predicted by poor performance on any one measure of face processing.     

Analysis of group differences in processing speed: Where are the models of processing?

Recently, Myerson, Adams, Hale, and Jenkins (2003) replied to arguments advanced by Ratcliff, Spieler, and McKoon (2000) about interpretations of Brinley functions. Myerson et al. (2003) focused on methodological and terminological issues, arguing that (1) Brinley functions are not quantile-quantile (QQ) plots of distributions of mean reaction times (RTs) across conditions; that the fact that the slope of a Brinley function is the ratio of the standard deviations of the two distributions of means has no implications for the use of slope as a measure of processing speed; that the ratio of slopes of RT functions for older and young subjects plotted against independent variables equals the Brinley function slope; and that speed-accuracy criterion effects do not account for slowing with age. We reply by showing that Brinley functions are plots of quantiles against quantiles; that the slope is best estimated by the ratio of standard deviations because there is variability in the distributions of mean RTs for both older and young subjects; that the interpretation of equality of the slopes Brinley functions and plots of RTs against independent variables in terms of processing speed is model dependent; and that speed-accuracy effects in some, but not all, experiments are solely responsible for Brinley slopes greater than 1. We conclude by reiterating the point that was not addressed in Myerson et al. (2003), that the goal of research should be modelbased accounts of processing that deal with correct and error RT distributions and accuracy.     

What causes the effect of age of acquisition in lexical processing?

Three hypotheses for effects of age of acquisition (AoA) in lexical processing are compared: the cumulative frequency hypothesis (frequency and AoA both influence the number of encounters with a word, which influences processing speed), the semantic hypothesis (early-acquired words are processed faster because they are more central in the semantic network), and the neural network model (early-acquired words are faster because they are acquired when a network has maximum plasticity). In a regression study of lexical decision (LD) and semantic categorization (SC) in Italian and Dutch, contrary to the cumulative frequency hypothesis, AoA coefficients were larger than frequency coefficients, and, contrary to the semantic hypothesis, the effect of AoA was not larger in SC than in LD. The neural network model was supported.     

What causes the effect of age of acquisition in lexical processing?

Three hypotheses for effects of age of acquisition (AoA) in lexical processing are compared: the cumulative frequency hypothesis (frequency and AoA both influence the number of encounters with a word, which influences processing speed), the semantic hypothesis (early-acquired words are processed faster because they are more central in the semantic network), and the neural network model (early-acquired words are faster because they are acquired when a network has maximum plasticity). In a regression study of lexical decision (LD) and semantic categorization (SC) in Italian and Dutch, contrary to the cumulative frequency hypothesis, AoA coefficients were larger than frequency coefficients, and, contrary to the semantic hypothesis, the effect of AoA was not larger in SC than in LD. The neural network model was supported.     

What are the phenomena of physics?

Depending on different positions in the debate on scientific realism, there are various accounts of the phenomena of physics. For scientific realists like Bogen and Woodward, phenomena are matters of fact in nature, i.e., the effects explained and predicted by physical theories. For empiricists like van Fraassen, the phenomena of physics are the appearances observed or perceived by sensory experience. Constructivists, however, regard the phenomena of physics as artificial structures generated by experimental and mathematical methods. My paper investigates the historical background of these different meanings of “phenomenon” in the traditions of physics and philosophy. In particular, I discuss Newton’s account of the phenomena and Bohr’s view of quantum phenomena, their relation to the philosophical discussion, and to data and evidence in current particle physics and quantum optics.     

What are the positive consequences of illness?

Abstract

Fifty five people, either currently sick or having recovered from their illness, were recruited if they reported positive consequences of illness. They were questioned about their experiences of illness, 41 by semi-structured interview and 14 by open-ended questionnaire and responses were classified into 17 categories. The categories were similar but slightly more extensive than previous accounts of positive consequences reported in the literature. The content of the interviews and questionnaires was used to construct a 66 item questionnaire about positive consequences of illness which was then completed by 97 patients. A principal components analysis indicated a large first factor accounting for 27% of the variance. Endorsement of items varied between 87% and zero for chronic lung disease patients attending pulmonary rehabilitation. However, all patients endorsed at least one item and the median number of items endorsed was 31. Positive consequences of illness are highly varied and more common than often realised, and this has implications for the concept and measurement of quality of life.     

What are the objects of perceptual consciousness?

Four answers to the title question are critically reviewed. (a) The first answer proposes that we perceive our brain events, certain occurrences in our brain that appear to us as parts of the environment. (b) Gestalt psychology distinguishes the phenomenal from the physical and proposes that we always perceive some aspect of our own phenomenal world--which is isomorphic but not identical to certain of our brain events. (c) J. J. Gibson held that our perceptual experiences are registrations of properties of the external environment--which is, therefore, perceived directly (i.e., without experiencing anything else). (d) The fourth answer comprehends perceptual experience to be a qualitative form of noninferential awareness of the apparent properties of specific environmental things. It differs from Gibson's answer in several respects, including the claim that some aspect of the external world appears to us whenever we have perceptual experience.     

Is predictive processing a theory of perceptual consciousness?

Predictive Processing theory, hotly debated in neuroscience, psychology and philosophy, promises to explain a number of perceptual and cognitive phenomena in a simple and elegant manner. In some of its versions, the theory is ambitiously advertised as a new theory of conscious perception. The task of this paper is to assess whether this claim is realistic. We will be arguing that the Predictive Processing theory cannot explain the transition from unconscious to conscious perception in its proprietary terms. The explanations offered by PP theorists mostly concern the preconditions of conscious perception, leaving the genuine material substrate of consciousness untouched.     

What are the shapes of response time distributions in visual search?

Many visual search experiments measure response time (RT) as their primary dependent variable. Analyses typically focus on mean (or median) RT. However, given enough data, the RT distribution can be a rich source of information. For this paper, we collected about 500 trials per cell per observer for both target-present and target-absent displays in each of three classic search tasks: feature search, with the target defined by color; conjunction search, with the target defined by both color and orientation; and spatial configuration search for a 2 among distractor 5s. This large data set allows us to characterize the RT distributions in detail. We present the raw RT distributions and fit several psychologically motivated functions (ex-Gaussian, ex-Wald, Gamma, and Weibull) to the data. We analyze and interpret parameter trends from these four functions within the context of theories of visual search.     

What are the Causes of the Attention Deficits Observed in Children with Dyslexia?

Dyslexic children often show attention problems at school, but it is not clear the nature of their impairments. The aim of this study was to analyze whether verbal processing artefacts could mediate attention deficits. Forty-seven children (22 dyslexics and 25 controls), aged between 7 to 12, were assessed through an ADHD rating scale and a battery of tasks tapping different attentional processes (selective, sustained, executive, and orienting). Phonological measures were used as covariates. Children with dyslexia showed attentional impairments (using both rating scales and neuropsychological tasks); however their performance was significantly affected by phonological performance. In conclusion, dyslexics may be inattentive at school because they are slow processors, in particular when they are presented with verbal stimuli.     

Which components of processing speed are affected in ADHD subtypes?

The term “processing speed” (PS) encompasses many components including perceptual, cognitive and output speed. Despite evidence for reduced PS in Attention-Deficit/Hyperactivity Disorder (ADHD), little is known about which component(s) is most impacted in ADHD, or how it may vary by subtypes. Participants included 151 children, ages 8–12 years, with ADHD Predominantly Inattentive Type, ADHD Combined Type and typically developing controls using DSM-IV criteria. All children completed four measures of processing speed: Symbol Search, Coding, Decision Speed, and simple reaction time. We found children with ADHD-PI and ADHD-C had slower perceptual and psychomotor/incidental learning speed than controls and that ADHD-PI had slower decision speed than controls. The subtypes did not differ on any of these measures. Mean reaction time was intact in ADHD. Hence, at a very basic output level, children with ADHD do not have impaired speed overall, but as task demands increase their processing speed becomes less efficient than controls’. Further, perceptual and psychomotor speed were related to inattention, and psychomotor speed/incidental learning was related to hyperactivity/impulsivity. Thus, inattention may contribute to less efficient performance and worse attention to detail on tasks with a higher perceptual and/or psychomotor load; whereas hyperactivity/impulsivity may affect psychomotor speed/incidental learning, possibly via greater inaccuracy and/or reduced learning efficiency. Decision speed was not related to either dimension. Results suggest that PS deficits are primarily linked to the inattention dimension of ADHD but not exclusively. Findings also suggest PS is not a singular process but rather a multifaceted system that is differentially impacted in ADHD.     

What are we frightened of?

I am concerned to understand that relation to a situation which we call fearing it. Some say this cannot be done: it is a brute fact about us that we fear certain things and we understand another's fear when we see that he confronts a situation of this sort (a basic fear object) or one which he understandably associates with this sort. In Section I, I argue that being associated with a basic fear object will not usefully explain a current fear. In Section II, I argue that the obvious candidates for being basic fears will not do the required work. The notion should be rejected. I then argue that to fear an object is to take it as exhibiting one's lack of control and I proceed to describe the nature and content of this notion.     

What are we really priming? Cue-based versus category-based processing of facial stimuli.

Results from 5 experiments provide converging evidence that automatic evaluation of faces in sequential priming paradigms reflects affective responses to phenotypic features per se rather than evaluation of the racial categories to which the faces belong. Experiment 1 demonstrates that African American facial primes with racially prototypic physical features facilitate more automatic negative evaluations than do other Black faces that are unambiguously categorizable as African American but have less prototypic features. Experiments 2, 3, and 4 further support the hypothesis that these differences reflect direct affective responses to physical features rather than differential categorization. Experiment 5 shows that automatic responses to facial primes correlate with cue-based but not category-based explicit measures of prejudice. Overall, these results suggest the existence of 2 distinct types of prejudice.     

What are the values of young people and how are these different from the values of older generations in Georgia?

This article examines the basic values of young people (aged 18 to 25) and analyses how, if at all, these are different from the values of older generations in Georgia. Based on Shalom H. Schwartz’s Theory of Basic Values (2012), the study uses quantitative (secondary analysis of the World Values Survey [WVS]) and qualitative (40 in-depth interviews) research methods to explore basic values, perceptions and attitudes, as well as tolerance towards different minority groups in Georgia. The research findings reveal that Schwartz’s higher-ordered values ‘conservation’ (including ‘conformity’ and ‘tradition’) and ‘self-transcendence’ (including ‘benevolence’ and ‘universalism’) are very important for all age groups in Georgia. In contrast, the values of ‘openness to change’ and ‘self-enhancement’ are assessed quite dissimilarly by young and older generations. In addition, the youth turned out to be more tolerant towards different minority groups, such as people of a different religion and race, immigrants and sexual minorities.     

What in the world are the ways things might have been?

Robert Stalnaker is an actualist who holds that merely possible worlds are uninstantiated properties that might have been instantiated. Stalnaker also holds that there are no metaphysically impossible worlds: uninstantiated properties that couldn't have been instantiated. These views motivate Stalnaker's "two dimensional" account of the necessary a posteriori on which there is no single proposition that is both necessary and a posteriori. For a (metaphysically) necessary proposition is true in all (metaphysically) possible worlds. If there were necessary a posteriori propositions, that would mean that there were propositions true in all possible worlds but which could only be known to be true by acquiring empirical evidence. Consider such a purported proposition P. The role of empirical evidence for establishing P's truth would have to be to rule out worlds in which P is false. If there were no such worlds to be ruled out, we would not require evidence for P. But by hypothesis, P is necessary and so true in all metaphysically possible worlds. And on Stalnaker's view, the metaphysically possible worlds are all the worlds there are. So there can be no proposition that is true in all possible worlds, but that we require evidence to know. In this way, the motivation for Stalnaker's two dimensional account of the necessary a posteriori rests on his denying that there are metaphysically impossible Worlds. I argue that given his view of what possible worlds are, Stalnaker has no principled reason for denying that there are metaphysically impossible worlds. If I am right, this undercuts Stalnaker's motivation for his two dimensional account of the necessary a posteriori.