Investigating neural representations: the tale of place cells

While neuroscientists often characterize brain activity as representational, many philosophers have construed these accounts as just theorists’ glosses on the mechanism. Moreover, philosophical discussions commonly focus on finished accounts of explanation, not research in progress. I adopt a different perspective, considering how characterizations of neural activity as representational contributes to the development of mechanistic accounts, guiding the investigations neuroscientists pursue as they work from an initial proposal to a more detailed understanding of a mechanism. I develop one illustrative example involving research on the information-processing mechanisms mammals employ in navigating their environments. This research was galvanized by the discovery in the 1970s of place cells in the hippocampus. This discovery prompted research in what the activity of these cells represents and how place representations figure in navigation. It also led to the discovery of a host of other types of neurons—grid cells, head-direction cells, boundary cells—that carry other types of spatial information and interact with place cells in the mechanism underlying spatial navigation. As I will try to make clear, the research is explicitly devoted to identifying representations and determining how they are constructed and used in an information processing mechanism. Construals of neural activity as representations are not mere glosses but are characterizations to which neuroscientists are committed in the development of their explanatory accounts.     

Case Report: Direct Access Genetic Testing and A False-Positive Result For Long QT Syndrome

We report the case of a woman who pursued direct access genetic testing and then presented with concerns regarding a positive test result for Long-QT syndrome. Although the result ultimately proved to be a false positive, this case illustrates that costs associated with follow-up of direct access genetic testing results can be non-trivial for both the patient and for health care systems. Here we raise policy questions regarding the appropriate distribution of these costs. We also discuss the possibility that, when confronted by a direct access genetic test result that reports high risk for one or more actionable diseases, a family physician might feel compelled to act out of a desire to avoid liability, even when information regarding the accuracy and validity of the testing were not easily accessible. This case outlines lessons that can easily be translated into clinical practice, not only by genetic counselors, but also by family physicians, medical specialists and members of the public.     

Psychologists in Academic Health Centers and Medical Centers: Being Visible,Relevant and Integral

Psychologists play key roles in academic health centers. This article is an outgrowth of a presentation at the 2015 Conference of the Association of Psychologists in Academic Health Centers addressing various strategies by which psychologists can effectively adapt to and develop successful careers in medical schools, academic health centers, and teaching hospitals. The authors encourage early career and mid-career psychologists in academic health centers to be active, engaged members of their institutions and to participate in multiple aspects of the research, educational, and clinical missions.     

Memory systems in the rat: effects of reward probability,context, and congruency between working and reference memory

The interaction of working and reference memory was studied in rats on an eight-arm radial maze. In two experiments, rats were trained to perform working memory and reference memory tasks. On working memory trials, they were allowed to enter four randomly chosen arms for reward in a study phase and then had to choose the unentered arms for reward in a test phase. On reference memory trials, they had to learn to visit the same four arms on the maze on every trial for reward. Retention was tested on working memory trials in which the interval between the study and test phase was 15 s, 15 min, or 30 min. At each retention interval, tests were performed in which the correct WM arms were either congruent or incongruent with the correct RM arms. Both experiments showed that congruency interacted with retention interval, yielding more forgetting at 30 min on incongruent trials than on congruent trials. The effect of reference memory strength on the congruency effect was examined in Experiment 1, and the effect of associating different contexts with working and reference memory on the congruency effect was studied in Experiment 2.     

The Dimensionality of Visual Space

The empirical study of visual space (VS) has centered on determining its geometry, whether it is a perspective projection, flat or curved, Euclidean or non-Euclidean, whereas the topology of space consists of those properties that remain invariant under stretching but not tearing. For that reason distance is a property not preserved in topological space whereas the property of spatial order is preserved. Specifically the topological properties of dimensionality, orientability, continuity, and connectivity define “real” space as studied by physics and are the spatial properties that characterize the physical universe as being an integral whole. By contrast the geometrical analysis of VS has taken little cognizance of its topology. Instead such properties have been presupposed a priori rather than being established a posteriori by empirical means, perhaps because these properties are self-evident. Applying the method of coordinative definition expounded by Hans Reichenbach for determining geometrical and topological properties of physical space (PS), it can be shown that VS fulfills the topological criteria of being a “real” space sui generis. Though theorized to be produced by the brain, the topology of VS is not topologically equivalent (homeomorphic) with the structure and activity of the brain because, as will be shown, the topology of VS cannot be formed from the topology of the brain without tearing and/or cutting and pasting.     

The Munroe-Meyer Approach: Continuous Integration of Didactic Instruction,Research, and Clinical Practice

Increased demand for applied behavior analysis (ABA) services has increased the need for additional masters-level practitioners and doctoral-level academicians and clinical directors. Based on these needs, the University of Nebraska Medical Center’s (UNMC) Munroe-Meyer Institute has developed a PhD program. The academic structure at UNMC allowed us to create our PhD program in a relatively quick and efficient manner. Our PhD program has many unique features, including (a) close integration of didactic instruction with clinical and research training provided by leading experts in ABA in which students immediately apply concepts introduced in the classroom during coordinated clinical and research practica; (b) structured grant writing training in which students learn to write and submit an NIH-level grant; (c) financial support in the form of a stipend of $23,400 per year, free health benefits, and a full-tuition waiver for up to 12 credits per semester for UNMC courses (a benefits package worth approximately $50,000 per year for an out-of-state student); and (d) encouragement and financial support to present papers at local, regional, and national behavior analysis conferences.     

Following Inspiration: A Conversation With Former First Lady Rosalynn Carter

Our distinguished guest for the 3rd installment in this inaugural Hearing our Elders series is former First Lady Rosalynn Carter. Mrs. Carter is arguably among the most active former First Ladies since she and her husband, the 39th President of the United States, James Earl “Jimmy” Carter, left the White House in 1981. The zeitgeist of the mid‐1950s through the 1970s provides the context that frames Mrs. Carter's responses to questions about her involvement in the mental health movement that continues to the present day. The historical as well as contemporary social and political environments relative to understanding and appreciating mental health and wellness in the United States, then and now, are explored and illuminated in portions of the interview with Mrs. Carter. The interview revealed 6 critical themes: really listening with an empathic ear, resilience/persistence, commitment across time, thinking like a global citizen, a quiet‐storm leadership style, and self‐discovery in service to others. Nuestra distinguida invitada en la 3ª entrega de esta serie inaugural de Escuchar a Nuestros Mayores es la ex Primera Dama Rosalynn Carter. La señora Carter es sin duda una de las ex primeras damas más activas desde que en 1981 dejó la Casa Blanca junto con su marido, el 39° Presidente de los Estados Unidos James Earl “Jimmy” Carter. El espíritu cultural del periodo entre la mitad de la década de los años 50 hasta los 70 proporciona el contexto en el que se enmarcan las respuestas de la señora Carter a preguntas sobre su implicación en el movimiento para la salud mental que continúa hasta hoy. Los entornos social y político de ayer y hoy, tanto en su perspectiva histórica como contemporánea, y cómo estos se relacionan con la comprensión y valoración de la salud y bienestar mental en los Estados Unidos se exploran e ilustran en varios segmentos de la entrevista con la señora Carter. Esta entrevista reveló 6 temas críticos: la escucha con atención y empatía, la resiliencia/persistencia, el compromiso a lo largo del tiempo, el pensamiento como ciudadanos globales, un estilo de liderazgo firme pero calmado, y el autodescubrimiento a través del servicio a otros.     

For God or Country? Comparing the Sources of Anti-American and Anti-Muslim Attitudes

Negative attitudes about Americans pervade the Muslim world. And many Americans hold negative views of Muslims. Although prior literatures provide many explanations for the sources of antagonism in each population, scholars have yet to provide a direct comparison between the two. Thus, instead of explaining the attitudes themselves, this research compares them. When the same questions are asked of Americans and Muslims, are the same variables significant predictors of antagonism? We use 2008 and 2011 survey data from the Pew Global Attitudes Project and ordered probit models to answer this question at two distinct points in time. The results illustrate the importance of domestic politics for both populations, providing insight into the potential utility of foreign policies designed to improve attitudes. Additionally, we find that the story of religion's influence on anti-American attitudes is a complex one, which changes depending on how religiosity is operationalized. This research represents a first step in bringing the literatures on anti-Muslim and anti-American attitudes together, while also revealing important similarities and differences in the sources of antagonism.     

Argentines’ collective memories of the military Junta of 1976: differences and similarities across generations and ideology

Although memories about a nation's past usually are semantic in nature, a distinction needs to be made between lived and distant semantic collective memories. The former refers to memories of community-relevant events occurring during the lifetime of the rememberer, whereas the latter to memories of distant events. Does the content of lived and distant semantic collective memories differ? Employing both free and cued recall, we examined the memories of younger and older Argentines of the Military Junta of 1976. We also examined the effects of political ideology. Content analysis indicated that (1) lived semantic collective memories were more likely to contain personal recollections than distant semantic collective memories, even though those with distant semantic collective memories could have incorporated memories of the parent's personal experience in their recollections, (2) lived semantic collective memories contained more causal statements, and (3) those on the Right with distant semantic collective memories were more likely to claim that they “Don't know” or offer positive accounts of the Junta, suggesting a need to “defend” the reputation of those on the Right. The results are discussed in terms of the goals and plans different generations might have when recollecting their nation's past.     

An improved spatial span test of visuospatial memory

In the widely used Corsi Block Test and Wechsler Spatial Span Tests, participants must reproduce sequences of blocks in the order touched by the examiner until two trials are missed at the same sequence length. The examiner records either the maximum number of blocks correctly reported or the total number of correct lists. Here, we describe a computerized spatial span test (C-SST) that uses psychophysical procedures to quantify visuospatial mean span (MnS) with sub-digit precision. Results from 187 participants ranging in age from 18 to 82 years showed that accuracy declined gradually with list length around the MnS (by ～30% per item). Simulation studies revealed high variance and biases in CBT and Wechsler measures, and demonstrated that the C-SST provided the most accurate estimate of true span (i.e., the sequence length producing 50% correct). MnS declined more rapidly with age than mean digit span (MnDS) measured in the same participants. Response times correlated with both MnS and MnDS scores. Error analysis showed that omission and transposition errors predominated, with weaker primacy and recency effects in spatial span than digit span testing. The C-SST improves the precision of spatial span testing and reveals significant differences between visuospatial and verbal working memory.