Generalizing the dynamic field theory of spatial cognition across real and developmental time scales

Within cognitive neuroscience, computational models are designed to provide insights into the organization of behavior while adhering to neural principles. These models should provide sufficient specificity to generate novel predictions while maintaining the generality needed to capture behavior across tasks and/or time scales. This paper presents one such model, the Dynamic Field Theory (DFT) of spatial cognition, showing new simulations that provide a demonstration proof that the theory generalizes across developmental changes in performance in four tasks—the Piagetian A-not-B task, a sandbox version of the A-not-B task, a canonical spatial recall task, and a position discrimination task. Model simulations demonstrate that the DFT can accomplish both specificity—generating novel, testable predictions—and generality—spanning multiple tasks across development with a relatively simple developmental hypothesis. Critically, the DFT achieves generality across tasks and time scales with no modification to its basic structure and with a strong commitment to neural principles. The only change necessary to capture development in the model was an increase in the precision of the tuning of receptive fields as well as an increase in the precision of local excitatory interactions among neurons in the model. These small quantitative changes were sufficient to move the model through a set of quantitative and qualitative behavioral changes that span the age range from 8 months to 6 years and into adulthood. We conclude by considering how the DFT is positioned in the literature, the challenges on the horizon for our framework, and how a dynamic field approach can yield new insights into development from a computational cognitive neuroscience perspective.

Science and the Climate Change Debacle

As I write this on the first business day of 2010, I find myself thinking about the importance of respecting alternative views --- not only alternative political views, but also alternative scientific views. Good science requires that we understand the limits of knowledge and continuously seek the truth through respectful questioning, replication and review. In the climate change debate, which recently culminated in a disappointing and largely ineffective conference in Copenhagen, these salient principles of science were grossly violated. Well respected climate scientists proceeded well beyond the limits of their knowledge and became policy advocates. They demeaned anyone who dared to disagree with their findings or to suggest that limiting CO2 emissions may not be the best policy choice at the present time. Disagreeing with the “experts” became disrespected professional behavior, even within the academic community. This approach has not served the interests of anyone very well.

Rural Nebraska: Looking Back at a Decade of Change and Progress: 2005 Nebraska Rural Poll Results

To commemorate the 10th anniversary of the Nebraska Rural Poll, rural Nebraskans were asked about changes they may have experienced during the past ten years. Where have they lived during the past decade? In what types of business activities have they been involved? Have they received any education or training during that time period? What has been their experience with the Internet? This report details 2,851 responses to the 2005 Nebraska Rural Poll, the tenth annual effort to understand rural Nebraskans’ perceptions. Respondents were asked a series of questions about changes they have experienced during the past ten years. For all questions, comparisons are made among different respondent subgroups, that is, comparisons by age, occupation, region, etc. Based on these analyses, some key findings emerged: One quarter of rural Nebraskans have lived somewhere other than their current community during the past ten years. Of those who have lived elsewhere, they have moved their primary residence an average of 2.2 times. Younger rural Nebraskans are more likely than older residents to have lived elsewhere during the past decade. Sixty-six percent of persons between the ages of 19 and 29 have lived in a different location, compared to only 12 percent of persons age 65 and older. Many rural Nebraskans who have lived in a different community during the past ten years have lived in another state. Forty-one percent of persons who have lived elsewhere during the past decade have lived in a different state. Forty-five percent have lived in a larger community (18% have lived in either Omaha or Lincoln and 27% have lived in or near a Nebraska community larger than their current one - other than Lincoln or Omaha). Thirty-six percent have lived in or near a Nebraska community smaller than their current one. Twenty percent of rural Nebraskans currently own a business. Thirteen percent started operating a business during the past ten years, 10 percent closed or stopped operating a business during this time period and four percent tried unsuccessfully to start a business. Persons living in or near the smallest communities are more likely than persons living in or near larger communities to currently own a business. Twenty-nine percent of persons living in or near communities with less than 500 people currently own a business, compared to 15 percent of persons living in or near communities with at least 10,000 persons. In general, rural Nebraskans have favorable opinions about self-employment but they also recognize the hardships and risks involved with this type of employment. Sixtyone percent agree that self-employment is desirable because they can be their own boss. Forty-four percent agree that self-employment provides a better quality of life than being an employee. However, 74 percent agree that self-employed individuals work longer hours than traditional employees and 70 percent agree that the cost of health insurance makes self-employment unappealing. Younger persons are more likely than older persons to agree that the cost of health insurance makes self-employment unappealing. Eighty percent of persons age 19 to 29 agree with that statement, compared to 55 percent of persons age 65 and older. One-half of rural Nebraskans have participated in formal education courses, workshops or other training activities during the past ten years. Sixty-nine percent of rural Nebraskans have Internet access either at home or at work. Sixty-six percent have acquired Internet access either at home or at work during the past ten years. An additional three percent had acquired access more than ten years ago. Persons with higher levels of income are more likely than persons with lower incomes to have acquired Internet access. Sixty-six percent of persons with household incomes of $60,000 or more have acquired Internet access at both home and work during the past ten years, compared to only 11 percent of persons with household incomes less than $20,000. Information searches and email are the most important reasons for having an Internet connection. Eighty-nine percent of rural Nebraskans with access to the Internet at either home or work say that information searches are an important or very important reason for having an Internet connection. Eighty-three percent say email is an important reason. In general, rural Nebraskans say their satisfaction with various features of their Internet connection has increased during the past ten years. Fifty-five percent of rural Nebraskans with an Internet connection at home say their satisfaction with the availability of service has increased during the past ten years and 50 percent report an increase in their satisfaction with the speed of their connection. Persons living in or near the larger communities are more likely than persons living in or near the smaller communities to say their satisfaction with the speed of their Internet connection has increased during the past ten years. Fifty-four percent of persons living in or near communities with populations of 5,000 or more say their satisfaction with the speed of their connection has increased over the past decade, compared to 43 percent of persons living in or near communities with less than 1,000 people.