Quantifier comprehension in corticobasal degeneration

In this study, we investigated patients with focal neurodegenerative diseases to examine a formal linguistic distinction between classes of generalized quantifiers, like "some X" and "less than half of X." Our model of quantifier comprehension proposes that number knowledge is required to understand both first-order and higher-order quantifiers. The present results demonstrate that corticobasal degeneration (CBD) patients, who have number knowledge impairments but little evidence for a deficit understanding other aspects of language, are impaired in their comprehension of quantifiers relative to healthy seniors, Alzheimer's disease (AD) and frontotemporal dementia (FTD) patients [F(3,77)=4.98; p<.005]. Moreover, our model attempts to honor a distinction in complexity between classes of quantifiers such that working memory is required to comprehend higher-order quantifiers. Our results support this distinction by demonstrating that FTD and AD patients, who have working memory limitations, have greater difficulty understanding higher-order quantifiers relative to first-order quantifiers [F(1,77)=124.29; p<.001]. An important implication of these findings is that the meaning of generalized quantifiers appears to involve two dissociable components, number knowledge and working memory, which are supported by distinct brain regions.     

Viewpoint and orientation influence picture recognition in the blind

In the first three experiments, subjects felt solid geometrical forms and matched raised-line pictures to the objects. Performance was best in experiment 1 for top views, with shorter response latencies than for side views, front views, or 3-D views with foreshortening. In a second experiment with blind participants, matching accuracy was not significantly affected by prior visual experience, but speed advantages were found for top views, with 3-D views also yielding better matching accuracy than side views. There were no performance advantages for pictures of objects with a constant cross section in the vertical axis. The early-blind participants had lower performance for side and frontal views. The objects were rotated to oblique orientations in experiment 3. Early-blind subjects performed worse than the other subjects given object rotation. Visual experience with pictures of objects at many angles could facilitate identification at oblique orientations. In experiment 5 with blindfolded sighted subjects, tangible pictures were used as targets and as choices. The results yielded superior overall performance for 3-D views (mean, M = 74% correct) and much lower matching accuracy for top views as targets (M = 58% correct). Performance was highest when the target and matching viewpoint were identical, but 3-D views (M = 96% correct) were still far better than top views. The accuracy advantage of the top views also disappeared when more complex objects were tested in experiment 6. Alternative theoretical implications of the results are discussed.     

CBT intensity and outcome for panic disorder in a primary care setting

A hybrid efficacy-effectiveness design in which participants (n = 91/93) were retained in the study regardless of whether or not they received treatment enabled evaluation of CBT intensity in relation to panic disorder in the primary care setting. CBT intensity was operationalized as number of cognitive-behavioral therapy sessions, number of follow-up booster phone calls, and secondarily, as number of cognitive behavioral coping and exposure strategies. Baseline psychosocial and demographic predictors of CBT intensity were analyzed first. Severity of anxiety sensitivity predicted number of cognitive behavioral sessions, but no baseline variables predicted number of follow-up booster phone calls or number of coping and exposure strategies. Multivariate logistic and linear regressions were used to evaluate the degree to which treatment intensity predicted 3-month and 12-month outcomes (anxiety sensitivity, phobic avoidance, depressive symptoms, disability, and medical and mental health functioning) after controlling for potential confounding baseline variables. Number of cognitive behavioral therapy sessions predicted lower anxiety sensitivity at 3 and 12 months, and number of follow-up booster phone calls predicted lower anxiety sensitivity, less phobic avoidance, and less depression at 12 months. These findings indicate that "dose" of psychotherapy was an important predictor of outcome. The significance of follow-up booster phone contact is discussed as an index of continued self-management of panic and anxiety following acute treatment.     

Ordinary variations in maternal caregiving influence human infants' stress reactivity

ABSTRACT— We sought to extend earlier work by examining whether there are ordinary variations in human maternal caregiving behavior (MCB) that are related to stress reactivity in infants. We observed 185 mother-infant dyads and used standard coding systems to identify variations in caregiving behavior. We then created two extreme groups and found that infants receiving low-quality MCB showed more fearfulness, less positive joint attention, and greater right frontal electroencephalographic asymmetry than infants receiving high-quality MCB. Group differences in stress reactivity were not a result of measured infant temperament. However, infants receiving low-quality MCB manifested significantly more negative affect during caregiving activities than did infants receiving high-quality MCB. The results suggest that ordinary variations in MCB may influence the expression of neural systems involved in stress reactivity in human infants.     

Processing Speed Deficits in Attention Deficit/Hyperactivity Disorder and Reading Disability

The goal of the current study was to test whether deficits in processing speed (PS) may be a shared cognitive risk factor in reading disability (RD) and Attention Deficit/Hyperactivity Disorder (ADHD), which are known to be comorbid. Literature on ADHD and RD suggests that deficits on tasks with a speeded component are seen in both of these disorders individually. The current study examined a wide range of speeded tasks in RD, ADHD, comorbid RD+ADHD, and a control group to test whether RD and ADHD have similar profiles of PS deficits, and whether these deficits are shared by the two disorders. The results suggest that a general PS deficit exists in both clinical groups compared to controls, although children with RD demonstrate greater PS deficits than children with ADHD. Two tests (underadditivity and partial correlations) were conducted to test whether these PS deficits are shared. Since we found that PS deficits were underadditive in the comorbid group and that partialling PS reduced the correlation between RD and ADHD, it appears that PS is a shared cognitive risk factor that may help explain the comorbidity of these two disorders.     

Large-scale neural network for sentence processing

Our model of sentence comprehension includes at least grammatical processes important for structure-building, and executive resources such as working memory that support these grammatical processes. We hypothesized that a core network of brain regions supports grammatical processes, and that additional brain regions are activated depending on the working memory demands associated with processing a particular grammatical feature. We used functional magnetic resonance imaging (fMRI) to test this hypothesis by comparing cortical activation patterns during coherence judgments of sentences with three different syntactic features. We found activation of the ventral portion of left inferior frontal cortex during judgments of violations of each grammatical feature. Increased recruitment of the dorsal portion of left inferior frontal cortex was seen during judgments of violations of specific grammatical features that appear to involve a more prominent working memory component. Left posterolateral temporal cortex and anterior cingulate were also implicated in judging some of the grammatical features. Our observations are consistent with a large-scale neural network for sentence processing that includes a core set of regions for detecting and repairing several different kinds of grammatical features, and additional regions that appear to participate depending on the working memory demands associated with processing a particular grammatical feature.     

The Nature and Time Course of Pragmatic Plausibility Effects

The experiments reported in this article used a delayed same/different sentence matching task with concurrent measurement of eye movements to investigate the nature of the plausibility effect. The results clearly show that plausibility effects are not due to low level lexical associative processes, but arise as a consequence of the processing of the earliest or most basic form of sentential meaning. In fact, when sentential implausibility and lexical association are varied simultaneously, it is only sentential implausibility that exerts an effect. Effects of implausibility occur rapidly—sometimes parafoveally—and are localised in the regions of the sentence where the implausibility occurs, suggesting an incremental interpretive process progressing on a roughly word-by-word basis. It is suggested that plausibility effects result from the operation of a heuristically-driven process of sentential interpretation. This appears to behave in a ‘modular’ fashion, despite being influenced by real world knowledge and probabilities.Particular thanks are due to Ken Forster for kindling the ideas which led to much of this work and to Merrill Garrett for posing impossible challenges, which, probably to everyone’s surprise, could in fact be met. I am also much indebted to Claire Boissiere, Emma Clayes, Clare Dobbin, Alan Kennedy, Julie-Ann Marshall, Ashley Murray, and Murray Rowan for their collaboration in this research.     

A cognitive architecture that combines internal simulation with a global workspace

This paper proposes a brain-inspired cognitive architecture that incorporates approximations to the concepts of consciousness, imagination, and emotion. To emulate the empirically established cognitive efficacy of conscious as opposed to non-conscious information processing in the mammalian brain, the architecture adopts a model of information flow from global workspace theory. Cognitive functions such as anticipation and planning are realised through internal simulation of interaction with the environment. Action selection, in both actual and internally simulated interaction with the environment, is mediated by affect. An implementation of the architecture is described which is based on weightless neurons and is used to control a simulated robot.     

Effects of nicotine administration via a sublingual tablet on arousal and verbal ability in non‐smokers

Tobacco smoking or nicotine administration on its own can influence cognitive task performance. This study examined the effects of acute nicotine administration on verbal task performance and a physiological index of arousal. Healthy non‐smoking participants received either a 2‐mg sublingual nicotine tablet or placebo. Participants next completed various verbal tasks while heart rate recordings were taken concurrently. Nicotine increased heart rate relative to a pre‐administration baseline period, indicating that the new method of nicotine administration increased cardiovascular arousal. Nicotine was associated with reduced accuracy in a verbal matching task and reduced accuracy and increased reaction time in an anagram task, but had no effect on performance during an analogy or verbal fluency task. The data suggest that nicotine‐naïve individuals are unlikely to gain any benefit to their verbal ability from the single acute intake of nicotine, such as that obtained from cigarette smoking or by using nicotine replacement therapy products.