Cognitive Science

Nonhungry rats received training consisting of intermixed presentations of a compound flavor and an element of that compound (AX, X, AX, X, . . .), and then a separate block of presentations of another compound (BX, BX, BX, . . .). Stimuli A and B were two odor solutions (almond and vanilla), and stimulus X was a highly concentrated solution of sucrose. After training, a state of hunger was induced in the rats, and their consumption levels of A and B alone were tested. We found higher test consumption of B than of A (Exp. 1). We interpreted these differences as indicating that the B-X association had become stronger than the A-X association as a result of the training. In Experiment 2, we demonstrated that the presence of X during training was necessary for that effect to appear (Exp. 2). These results give support to the recent proposal that within-compound associations are maintained better by blocked than by intermixed preexposure (Rodríguez & Alonso, 2014). We discuss the implic...

We present a theory of latent inhibition based on the Pearce-Hall (Pearce & Hall, 1980) model for classical conditioning. Its central features are (1) that the associability of a stimulus declines as it comes to predict its consequences and (2) that nonreinforced exposure to a stimulus engages an associative learning process that makes the stimulus an accurate predictor of its consequences (in this case, the occurrence of no event). A formalization of this theory is shown to accommodate the finding that preexposure in compound with another cue can potentiate latent inhibition to the target cue. It further predicts that preexposure to the added cue will eliminate the potentiation effect. An experiment using rats and the flavor-aversion procedure confirmed this prediction.

This article briefly describes the already known clinical features and pathogenic mechanisms underlying sporadic amyotrophic lateral sclerosis, namely excitoxicity, oxidative stress, protein damage, inflammation, genetic abnormalities and neuronal death. Thereafter, it puts forward the hypothesis that astrocytes may be the cells which serve as targets for the harmful action of a still unknown environmental agent, while neuronal death may be a secondary event following the initial insult to glial cells. The article also suggests that an emergent virus or a misfolded infectious protein might be potential candidates to accomplish this task.

To test previous signals of a risk of orofacial cleft (OC) and clubfoot with exposure to the antiepileptic lamotrigine, and to investigate risk of other congenital anomalies (CA). This was a population-based case-malformed control study based on 21 EUROCAT CA registries covering 10.1 million births (1995-2011), including births to 2005 in which the clubfoot signal was generated and a subsequent independent study population of 6.3 million births. A total of 226,806 babies with CA included livebirths, stillbirths, and terminations of pregnancy following prenatal diagnosis. First-trimester lamotrigine monotherapy exposure in OC cases and clubfoot cases was compared to other nonchromosomal CA (controls). Odds ratios (OR) were adjusted for registry. An exploratory analysis compared the proportion of each standard EUROCAT CA subgroup among all babies with nonchromosomal CA exposed to lamotrigine monotherapy with non-AED exposed pregnancies. There were 147 lamotrigine monotherapy-exposed b...

Emotional disorders are characterized by cognitive biases towards negative stimuli, and a lack of biases towards positive ones. Therefore, we developed a cognitive bias modification training, modifying approach-avoidance tendencies to diverse emotional pictures. In Study 1, a negative training (pull negative, push positive pictures) was compared to a positive training (vice versa) in 141 students. The pre-existing positivity bias remained after positive training, but reversed into a negativity bias after negative training. This effect transferred to an attentional bias. The training affected neither mood nor emotional vulnerability to stress. In Study 2, we investigated the effects of the positive training in 102 dysphoric and non-dysphoric students, all in a sad mood state. Compared to placebo training, the positive training strengthened a positivity bias, and it reduced emotional vulnerability in dysphoric students. This suggests potential therapeutic value of the training, but further studies are needed.

What do the evolution of upright posture and the origins of creative analogy have to do with each other? I propose that the two are vitally related. This book[*] documents the first phase of a larger project devoted to testing and refining this basic hypothesis. To do so, it becomes necessary to pay extensive attention to arms and legs—our appendage sets and the relationships that hold between them in movement and memory across our horizontal and vertical midlines. At their most extreme, the relationships that hold between our appendages give rise to new possibilities—prominently including the felt meanings, rhetorical powers and modeling affordances of X. The X figure is ubiquitous in contemporary culture, but attempts to explain our fixation with X are rare. In these pages, I explore the possibility that the X-mark is a figure of extremes and reversals—not primarily because of arbitrary cultural encoding but more basically because of entrenched body memories. These body memories involve our extremities, extended at extreme angles to form an extreme posture—a posture that is approximated across a wide range of experiences, many of which are extreme opposites. 

Chief among the uses and experiences of X are its tendencies to involve us in surprising reversals and blends. In ancient times the X-pattern was discussed as “chiasmus”, a figure which, according to Maurice Merleau-Ponty, informs the most basic elements of our bodily experience, calling into question polarized dichotomies such as subject versus object. Pushed to extremes, presumed opposites like these tend to reverse suddenly. Likewise, blended experiences of our bodily extremities - arms and legs, toes and fingers, hands and feet - provide a plausible source of grounding for unique human abilities like creative analogy or "double-scope conceptual integration". The book illustrates these dynamics by drawing attention to uses of X in history, prehistory and daily life, from sports and advertising to world mythology and languages around the world.

In short, the book argues that the origins and meanings of X go far beyond alphabets and archetypes to remembered feelings of body movements. These body memories are then projected onto other patterns and dynamics to help us make sense of the world. The argument is accomplished using a blend of insights from linguistic anthropology, cognitive linguistics, rhetoric culture and process semiotics to bring together revealing clues from languages, cultures and thinkers around the world. The Semiotics of X is the first step towards developing a larger argument on the important but neglected role that chiasmus plays in cognition. It aims to inspire continued exploration on the figure, with the full expectation that chiasmus will become for the 21st century what metaphor became for the 20th century: a revolution in thinking about the way we think.
*[Note: the pdf posted here includes title pages, Table of Contents, Preface and Chapter 1 only].

Glycogen synthase kinase-3 beta (GSK3β) is a ubiquitous kinase that is part of multiple signaling pathways. It has neurotrophic/neuroprotective effects by mediating the actions of neurotrophic molecules in the brain, thus providing neuroprotection through modulation of energy metabolism. Notably, it has been demonstrated that GSK3β is involved in Wnt-beta-catenin signaling, which contributes to the inhibition of myelination and remyelination processes in mammals. Three-hundred nineteen patients with MS and 294 age-matched controls were genotyped by allelic discrimination for four common GSK3β variants (rs2199503, rs9826659, rs334558 and rs6438552) tagging about 100% of GSK-3β variability. A statistically significant increased frequency of the rs334558 GG genotype was observed in patients as compared with controls (25.4% versus 17.7%, P=0.02; OR:1.58, 95%CI: 1.07-2.34). Stratifying MS patients according to the disease subtype, a statistically significant difference of rs334558 GG frequency was found between Relapsing Remitting (RR), but not Primary Progressive or Secondary MS, and controls (27.0% versus 17.7%, P=0.01; OR: 1.72, 95%CI: 1.13-2.61). GSK3β rs334558 is a susceptibility factor for MS. As it is located in the promoter region, a possible explanatory mechanism could be an influence of the variant on the gene transcription rate.

We followed 419 patients with a first, unprovoked, primarily or secondarily generalized tonic-clonic seizure, randomized to immediate antiepileptic treatment or to treatment only in the event of seizure recurrence. The probability of achieving a 2-year remission was 72 vs 57% at 3 months, 84 to 79% at 3 years, and 85 to 86% at 10 years (p = NS). The probability of entering 5-year remission was 47 to 40, 58 to 58, and 64 to 64% (p = NS). Early treatment does not affect the long-term prognosis of epilepsy.

Obstructive sleep apnea (OSA) patients show compromised emotional and cognitive functions, including anterograde memory deficits. While some memory inadequacies in OSA may result from earlier-described structural deficits in the hippocampus, mammillary body injury also could contribute, since these structures receive projections from the hippocampus via the fornix, project heavily to the anterior thalamus, and have been implicated in other conditions with memory deficiencies, such as Korsakoff's syndrome. However, volume loss in mammillary bodies has not been reported in OSA, likely a consequence of logistic difficulties in size assessment. We evaluated mammillary body volumes in 43 OSA (mean age+/-S.D., 46.9+/-9.2 years; mean apnea-hypopnea-index+/-S.D., 31.2+/-19.9 events/h) and 66 control subjects (age, 47.3+/-8.9 years). Two high-resolution T1-weighted image volumes were collected on a 3.0 T magnetic resonance scanner, averaged to improve signal-to-noise, and reoriented (without warping) into a common space. Brain sections containing both mammillary bodies were oversampled, and the bodies were manually traced and volumes calculated. OSA patients showed significantly reduced left, right, and combined mammillary body volumes compared with control subjects, after partitioning for age, gender, and head size (multivariate linear model,…

Congenital deformities involving the coverings of the nervous system are called neural tube defects (NTDs). NTD can be classified as neurulation defects, which occur by stage 12, and postneurulation defects. Cervical meningocele and myelomeningocele are rare spinal dysraphic lesions. Unlike lumbosacral dysraphic lesions, there is often no neurologic deficits and thus the subtle features of cervical cord tethering may be overlooked on imaging. The presence of meningomyelocele and/or encephaloceles at multiple (two or more) sites along the vertebral axis is a very rare event occurring in <1% of cases. Less than 10 cases have been described in the published literature. We are reporting a case of multiple NTD in same patient with no neurological deficit.

Infection of the central nervous system is a life-threatening condition in the pediatric population. Almost all agents can cause infection within the central nervous system and the extent of infection ranges from diffuse involvement of the meninges, brain, or the spinal cord to localized involvement presenting as a space-occupying lesion. Modern imaging techniques define the anatomic region infected, the evolution of the disease, and help in better management of these patients. Acute bacterial meningitis remains a major cause of mortality and long-term neurological disability. Fortunately, the incidence of infection after clean craniotomy is < 5%, but it leads to significant morbidity as well as fiscal loss. The most significant causative factor in postcraniotomy infections is postoperative CSF leak. Cerebral abscess related to organic congenital heart disease is one of the leading causes of morbidity and mortality in the pediatric population. The administration of prophylactic antibiotics is indicated for contaminated and clean-contaminated wounds.

The relation among hand, foot and eye lateral preference indices and certain verbal ability tests was studied in a group of 497 elementary school children. According to the performance on the verbal ability tests, the original sample was divided into a Lower and an Upper Group, and percentages of left preferences, consistent right and left preferences, crossed hand-foot, hand-eye, foot-eye preferences and congruent preferences were compared. The only comparison that proved to be significant was the evidence of a lower left preference percentage in reading speed in the Upper Group as compared to the Lower Group. A similar series of comparisons between a subgroup (N = 14) of children with serious reading problems and the group as a whole, did not lead to significant results. We therefore conclude that at least for subjects regularly attending school, there is no relation among lateral preference and the above mentioned verbal skills.