The Prolongevists Speak Up: The Life-Extension Ethics Session at the 10th Annual Congress of the International Association of Biomedical Gerontology

Life-extension was the focus for the 10th annual Congress of the International Association of Biomedical Gerontology, held last September at Cambridge University. This scientific convention included a panel of several bioethicists, including Art Caplan, John Harris, and others. The presentations on the ethics of life-extension are reviewed here.     

Inferred threat and safety: Symbolic generalization of human avoidance learning

Symbolic generalization of avoidance may underlie the aetiology and maintenance of anxiety disorders. The aim of the present study was to demonstrate inferred threat-avoidance and safety (non-avoidance) behaviours that occur in the presence of stimuli indirectly related to learned threat and safety cues. A laboratory experiment was conducted involving two symbolic stimulus equivalence relations consisting of three physically dissimilar stimuli (avoidance cues: AV1–AV2–AV3 and neutral cues: N1–N2–N3). During avoidance learning involving aversive images and sounds, a key-press avoidance response was trained for one member of one of the relations (AV2) and non-avoidance for another (N2). Inferred threat and safety behaviour and ratings of the likelihood of aversive events were tested with presentations of all remaining stimuli. Findings showed a significantly high percentage of avoidance to both the learned and inferred threat cues and less avoidance to both the learned and inferred safety cues. Ratings in the absence of avoidance were high during training and testing to threat cues and low to safety cues and were generally lower in the presence of avoidance. Implications for associative and behavioural accounts of avoidance, and modern therapies for anxiety disorders are discussed.     

The COST of explicit memory

Within Piaget there is an implicit theory of the development of explicit memory. It rests in the dynamical trajectory underlying the development of causality, object, space and time – a complex (COST) supporting a symbolic relationship integral to the explicit. Cassirer noted the same dependency in the phenomena of aphasias, insisting that a symbolic function is being undermined in these deficits. This is particularly critical given the reassessment of Piaget’s stages as the natural bifurcations of a self-organizing dynamic system. The elements of a theoretical framework required to support explicit memory are developed, to include, (1) the complex developmental trajectory supporting the emergence of the explicit in Piaget, (2) the concrete dynamical system and the concept of a non-differentiable time contained in Bergson’s theory required to support a conscious, as opposed to an implicit remembrance, (3) the relation to current theories of amnesia, difficulties posed by certain retrograde amnesic phenomena, the role of the hippocampus and limitations of connectionist models, (4) the fact that nowhere in this overall framework does the loss of explicit memory imply or require the destruction of experience “stored in the brain.”     

Typical and atypical development of basic numerical skills in elementary school

Deficits in basic numerical processing have been identified as a central and potentially causal problem in developmental dyscalculia; however, so far not much is known about the typical and atypical development of such skills. This study assessed basic number skills cross-sectionally in 262 typically developing and 51 dyscalculic children in Grades 2, 3, and 4. Findings indicate that the efficiency of number processing improves over time and that dyscalculic children are generally less efficient than children with typical development. For children with typical arithmetic development, robust effects of numerical distance, size congruity, and compatibility of ten and unit digits in two-digit numbers could be identified as early as the end of Grade 2. Only the distance effect for comparing symbolic representations of numerosities changed developmentally. Dyscalculic children did not show a size congruity effect but showed a more marked compatibility effect for two-digit numbers. We did not find strong evidence that dyscalculic children process numbers qualitatively differently from children with typical arithmetic development.     

Principled ideology or racism: Why do modern racists oppose race-based social justice programs?

People who score high on modern racism scales consistently oppose reparations for race-based social injustices. Scholars debate whether this opposition reflects racism [e.g., Sears, D. O., & Henry, P. J. (2005). Over thirty years later: A contemporary look at symbolic racism. In M.P Zanna, (Ed.), Advances in experimental social psychology, Vol. 37 (pp. 95-150). San Diego, CA: Elsevier Academic Press] or a principled conservative ideology [e.g., Sniderman, P. M., & Tetlock, P. E. (1986). Symbolic racism: Problems of motive attribution in political analysis. Journal of Social Issues, 42, 129-150]. We tested these competing hypotheses by examining support for government reparations for adult survivors of childhood abuse. We manipulated whether the survivors were of European or Aboriginal heritage. Consistent with a racism hypothesis, high modern racists indicated less support for reparations when the survivors were of Aboriginal heritage than when the survivors were of European heritage. Interestingly, low modern racists supported reparations more for Aboriginal Canadian than European Canadian survivors. We discuss three explanations of the responses of low modern racists.     

Symbolic versus associative learning

Ramscar and colleagues (2010, this volume) describe the "feature-label-order" (FLO) effect on category learning and characterize it as a constraint on symbolic learning. I argue that FLO is neither a constraint on symbolic learning in the sense of "learning elements of a symbol system" (instead, it is an effect on nonsymbolic, association learning) nor is it, more than any other constraint on category learning, a constraint on symbolic learning in the sense of "solving the symbol grounding problem."     

In the Face of Terrorism: Evidence that Belief in Literal Immortality Reduces Prejudice Under Terrorism Threat

Based on terror management theory, previous research has shown that terrorism threat increases prejudice against Muslims and is mediated by death‐related thoughts. Because this effect was found on a correlational level, it remains unclear whether terrorism threat increases prejudice against Muslims because of enhanced death‐related thoughts or the opposite: terrorism threat increases death‐related thoughts because of stronger prejudice against Muslims. To disentangle this shortcoming, we varied death‐related thoughts by systematically manipulating the belief in literal immortality. Using two studies, we found that participants exposed to terrorism pictures (vs. controls) had increased prejudice against both Muslims (Study 1) and immigrants (Study 2) when they were led to believe that literal immortality does not exist but not when they were led to believe that it does exist. Mediation analysis indicated that this effect was mediated by death‐related thoughts. This provides further evidence that terrorism threat increases prejudice because of death‐related thoughts.