Integrating psychological approaches to entrepreneurship: the Entrepreneurial Personality System (EPS)

Understanding the psychological nature and development of the individual entrepreneur is at the core of contemporary entrepreneurship research. Since the individual functions as a totality of his or her single characteristics (involving the interplay of biological, psychosocial, and context-related levels), a person-oriented approach focusing on intraindividual dynamics seems to be particularly fruitful to infer realistic implications for practice such as entrepreneurship education and promotion. Applying a person-oriented perspective, this paper integrates existing psychological approaches to entrepreneurship and presents a new, person-oriented model of entrepreneurship, the Entrepreneurial Personality System (EPS). In the empirical part, this model guided us to bridge two separate research streams dealing with entrepreneurial personality: research on broad traits like the Big Five and research on specific traits like risk-taking, self-efficacy, and internal locus of control. We examine a gravity effect of broad traits, as assumed in the EPS framework, by analyzing large personality data sets from three countries. The results reveal a consistent gravity effect of an intraindividual entrepreneurial Big Five profile on the more malleable psychological factors. Implications for entrepreneurship research and practice are discussed

A Role for Calcium-Permeable AMPA Receptors in Synaptic Plasticity and Learning

A central concept in the field of learning and memory is that NMDARs are essential for synaptic plasticity and memory formation. Surprisingly then, multiple studies have found that behavioral experience can reduce or eliminate the contribution of these receptors to learning. The cellular mechanisms that mediate learning in the absence of NMDAR activation are currently unknown. To address this issue, we examined the contribution of Ca[superscript 2+]-permeable AMPARs to learning and plasticity in the hippocampus. Mutant mice were engineered with a conditional genetic deletion of GluR2 in the CA1 region of the hippocampus (GluR2-cKO mice). Electrophysiology experiments in these animals revealed a novel form of long-term potentiation (LTP) that was independent of NMDARs and mediated by GluR2-lacking Ca2+-permeable AMPARs. Behavioral analyses found that GluR2-cKO mice were impaired on multiple hippocampus-dependent learning tasks that required NMDAR activation. This suggests that AMPAR-mediated LTP interferes with NMDAR-dependent plasticity. In contrast, NMDAR-independent learning was normal in knockout mice and required the activation of Ca[superscript 2+]-permeable AMPARs. These results suggest that GluR2-lacking AMPARs play a functional and previously unidentified role in learning; they appear to mediate changes in synaptic strength that occur after plasticity has been established by NMDARs.National Health and Medical Research Council (Australia) (Grant number 188819)National Institute of Mental Health (U.S.) (grant P50-MH58880)National Science Foundation (U.S.) (grant number 0543651)National Institute of Mental Health (U.S.) (grant number MH609197)National Institute of Mental Health (U.S.) (MH62122