The role of the hippocampus in the retrieval of a spatial location

Based on computational models of the hippocampus, it has been suggested that a possible mechanism for memory retrieval is pattern completion, wherein an autoassociative network recalls previous patterns of activity given noisy or degraded cues. However, there are few behavioral data examining pattern completion per se in the hippocampus. Here, we present a study in which rats were tested on a spatial location retrieval paradigm, each trial of which consisted of a sample and choice phase. During the sample phase, rats were trained to displace an object in one of 15 possible locations to retrieve a food reward and return to the start-box on a cheeseboard maze. The object was then removed and the same location was re-baited for the choice phase. The rats' accuracy in returning to the correct location was recorded. On test trials, visual extramaze cues, vestibular cues, or both were manipulated to assess pattern completion in normal rats. Subjects were then randomly assigned to receive a cortical control, a sham, or a dorsal and ventral hippocampal lesion and were retested on the task. Control and unoperated rats were able to perform the task when visual extramaze or vestibular cues were reliable, but not when they were manipulated. Rats with hippocampal lesions were impaired in the baseline condition, as well as during all manipulations. These results support the hypothesis that the hippocampus supports the retrieval of a spatial location, possibly through a process of pattern completion.     

Retrieving text inferences: Controlled and automatic influences

Bridging inferences contribute to text coherence by identifying the connections among ideas, whereas elaborative inferences simply specify sensible extrapolations from text. Bridging inferences have been indistinguishable from explicit text ideas on numerous measures, suggesting similar longterm memory (LTM) representations for the two, whereas elaborative inferences are inferior. To evaluate the LTM representations of text ideas, we used the extended process-dissociation procedure (Buchner, Erdfelder, & Vaterrodt-Plunnecke, 1995; Jacoby, 1991) to partition the controlled, recollective contributions to text retrieval from the automatic, familiarity-based contributions. The automatic contribution to the recognition of implied concepts was consistently negligible, an outcome consistent with the absence of perceptual processing of those concepts during the original reading. In addition, the controlled basis of recognition was consistently higher for explicit than for implicit concepts, which suggests a more robust conceptual representation for explicit text ideas (Yonelinas, 2002). These results were interpreted to reflect the asymmetric representation of explicit ideas and inferences (elaborative and even bridging inferences) in the surface, propositional textbase, and situational levels of text representation.     

Contextualism and the Skeptic: Comments on Engel

Mylan Engels paper (2004) is divided into two parts: a negative part, criticizing the costs of contextualism and a constructive part proposing a noncontextualist resolution of the skeptical problem. I will only address the constructive part here. The constructive part is composed of three elements: (i) a reconstruction or reformulation of the original skeptical argument, which draws on the notion of epistemic possibility (e-possibility), (ii) a distinction between two senses of knowledge (and two corresponding kinds of e-possibility): fallibilistic and infallibilistic, and (iii) an argument which tries to hoist the skeptic by their own petard, namely the closure principle (CP). As I will argue, there are two ways to understand Engels anti-skeptical argument. Only in one interpretation does the argument depend on the proposed reconstruction of the skeptical argument in terms of e-possibility. But this version of the argument is unsound. More importantly, the skeptic has a strong prima facie objection at her disposal, which applies to both interpretations of the argument. If this objection is valid, Engels argument does not hold. But once it is invalidated, his argument is superfluous.     

Location, location, location: the misprediction of satisfaction in housing lotteries

People tend to overestimate the emotional consequences of future life events, exhibiting an impact bias. The authors replicated the impact bias in a real-life context in which undergraduates were randomly assigned to dormitories (or "houses"). Participants appeared to focus on the wrong factors when imagining their future happiness in the houses. They placed far greater weight on highly variable physical features than on less variable social features in predicting their future happiness in each house, despite accurately recognizing that social features were more important than physical features when asked explicitly about the determinants of happiness. In Experiment 2, we found that this discrepancy emerged in part because participants exhibited an isolation effect, focusing too much on factors that distinguished between houses and not enough on factors that varied only slightly, such as social features.     

Substance use and partner violence among urban women seeking emergency care

Growing evidence suggests intimate partner violence (IPV) and substance misuse are co-occurring problems that disproportionately affect low income urban women seeking care in emergency departments (EDs) and represent leading causes of injuries that result in ED visits. This paper examines temporal bidirectional associations between different types of drug and alcohol use and different types of IPV in a longitudinal study of a representative sample of 241 low-income urban women receiving emergency care from an ED in the Bronx, New York. After adjusting and matching for sociodemographics and potentially confounding multilevel risk and protective covariates, women who reported using heroin in the prior 6 months at Wave 1 were twice as likely as nonheroin-using women to indicate any physical, injurious, or sexual IPV at subsequent waves and were 2.7 times more likely to indicate experiencing an injury from IPV at subsequent waves. Crack or cocaine use in the past 6 months at Wave 1 was associated with an increased likelihood of injurious IPV and severe verbal abuse at subsequent waves. Findings also suggested that sexual IPV was significantly associated with subsequent use of crack or cocaine. The multiple bidirectional associations found linking these problems underscore the need for conducting routine screening for IPV and substance misuse among women in low-income urban EDs, and for improving linkages to services that will ultimately reduce the risk of morbidity, disability, and mortality related to these co-occurring problems.     

Relationship between reaction time variability and motor skill development in ADHD

Slower and more variable reaction times to computerized tasks have been documented in children diagnosed with attention deficit/hyperactivity disorder (ADHD). Recent research supports a role for attentional lapses in generating abnormally variable and slow responses. However, given the association between ADHD and impairments in motor control, we hypothesized that slower or more variable reaction times might also correlate with motor development. The aim of this case-control study was to explore the relationship between motor function, reaction speed and variability, and ADHD. After comprehensive educational and clinical assessments, motor skill development was evaluated in 35 children ages 9 to 14 (19 with ADHD) using the Physical and Neurological Examination for Subtle Signs (PANESS) test battery. Finger-sequencing speed and variability were quantified with goniometers. Reaction times were measured with 20 trials each of computerized simple and choice (binary) tasks. Compared to healthy controls, children with ADHD had slower and more variable reaction times, and these findings correlated with impaired motor development (PANESS) and slow and variable finger sequencing (goniometers). Further studies of motor development in ADHD may identify factors influencing speed and variability of reaction times.     

Curious Disappearances: Affectability Imbalances and Process‐Based Invisibility

In this paper, we analyze the recent public scandal involving Nafissatou Diallo and Dominique Strauss‐Kahn to offer an account of the role affectability imbalances play in process‐based invisibility. Process‐based invisibilities, in this paper, refer to predictable narrative gaps within public narratives that can be aptly described as disappearances. We demonstrate that compromised, complex social identities, maladjusted webs of reciprocity, and a failure to fully appreciate basic affectability in large part cause affectability imbalances. Ultimately, we claim that affectability imbalances and the three imbricated conditions that facilitate such imbalances—complex social identities, reciprocity, and basic affectability—are integral features of process‐based invisibility.     

The study of sequence learning in individuals with schizophrenia: A critical review of the literature

The serial reaction time task (SRTT) has been used extensively to study implicit sequence learning. A number of studies have used the SRTT to examine sequence learning in schizophrenia patients. Despite these studies, it remains unclear whether sequence learning is impaired in patients, whether antipsychotic medications affect sequence learning, and what types of sequential information patients might have difficulty learning. Methodological limitations have made it difficult to obtain good answers to these questions. Methodological innovations from the general SRTT literature that have not yet been adopted in the schizophrenia literature could provide better answers.     

Print Me an Organ? Ethical and Regulatory Issues Emerging from 3D Bioprinting in Medicine

Recent developments of three-dimensional printing of biomaterials (3D bioprinting) in medicine have been portrayed as demonstrating the potential to transform some medical treatments, including providing new responses to organ damage or organ failure. However, beyond the hype and before 3D bioprinted organs are ready to be transplanted into humans, several important ethical concerns and regulatory questions need to be addressed. This article starts by raising general ethical concerns associated with the use of bioprinting in medicine, then it focuses on more particular ethical issues related to experimental testing on humans, and the lack of current international regulatory directives to guide these experiments. Accordingly, this article (1) considers whether there is a limit as to what should be bioprinted in medicine; (2) examines key risks of significant harm associated with testing 3D bioprinting for humans; (3) investigates the clinical trial paradigm used to test 3D bioprinting; (4) analyses ethical questions of irreversibility, loss of treatment opportunity and replicability; (5) explores the current lack of a specific framework for the regulation and testing of 3D bioprinting treatments.