Genetic engineering: prospects and recommendations--recommendations of the 1983 Summer Conference of the Institute on Religion in an Age of Science, Star Island, N.H., 30 Jul-6 Aug 1983

Abstract. At the 1983 Summer Conference on the Institute on Religion in an Age of Science, working groups chaired by the coauthors outlined some of the prospects for the use of somatic and germ line genetic engineering and related biological technologies to alleviate disease and to modify human behavior. They then offered a series of recommendations concerning the application of genetic engineering to persons and the monitoring of medical research and therapy.     

Ruler vs. the Apple II/FIRST system analysis of analog signals in classical conditioning

In our judgment, the Apple II/FIRST system (Scandrett & Gormezano, 1980) is an efficient and versatile system for experimental control and data acquisition in classical conditioning experiments. However, these attributes would be of limited value if the system did not extract measures from our analog signals with a high degree of correspondence with our ruler measurement procedures. Accordingly, we determined the system’s validity in extracting measures of CR occurrence and CR latency in three conditioning experiments. Pearson productmoment correlation coefficients indicated a very satisfactory degree of agreement on measurements made by the Apple II/FIRST system and ruler. Moreover, intraclass correlations and analysis of variance procedures applied to percent CRs and CR latency revealed several small, but divergent, differences between ruler and computer measurement of CR latency across the three experiments. However, subsequent analyses of variance revealed that the number and pattern of significant sources of variation for ruler or computer measurements were virtually identical. Accordingly, we have concluded that our system can successfully replace our traditional method of ruler measurement.     

Dissimilation,differential assimilation and social identity

Studied the behaviour of subjects in a ‘normalization’ experiment: when a consistent confederate adopts the subject's norms (adoption situation); when the consistent response of the confederate deviates from the subject's norm (distance situation). We had three conditions for each of these two modes of response: we manipulated the C's image (C was always similar to the subject), and the image of a reference population: C and S were both either very similar (C and S in the majority) or very dissimilar (C and S in the minority) to the population. Or there was no image manipulation. Sixty male subjects participated in this experiment: 10 subjects in each of the six experimental conditions. In two adoption conditions (no image, C and S in the majority) the subjects changed their responses when the confederate adopted their norm. Our hypothesis on the resistance to influence in one of the distance condition (C and S in the minority) was not verified. Thus we have shown that a phenomenon of differential dissimilation exists, but our previous results on differential assimilation are not replicated. These results are coherent with the social differentiation and originality theory which stresses the quest for social identity and distinctiveness by actors who do not ‘react’ but who, in certains situations, elaborate strategies.     

Visual Marking of Locations and Feature Maps: Evidence from Within-dimension Defined Conjunctions

Recently, Watson and Humphreys (1997, 1998) proposed that the selection of new visual events can be aided by the top-down inhibition of old information-visual marking (VM) and that the mechanisms of marking differ for static and moving stimuli. Stationary stimuli are marked by location-based inhibition, whereas moving stimuli are marked by inhibition applied at the level of whole-feature maps. Here we provide a test of this 'two-mechanism' account. We show that static items can be marked even when old and new stimuli contain the same features and so cannot be distinguished by activation within a unique feature map. However, moving old items could not be marked unless they possessed a unique feature (colour). Manipulations of grouping strength, both within and between distractor sets, did not affect the basic findings. The results support the existence of two mechanisms for VM and counter an object-based inhibition explanation of performance.     

Discrimination of multidimensional geometrical figures by chickens: categorization and pattern-learning

Japanese bantam hens were trained to discriminate between geometrical figures varying along four integral dimensions. Only one dimension predicted food: selections of sharp-cornered figures were reinforced, while selections of rounded figures were not. In experiment 1, hens were subsequently trained to discriminate between nine figure pairs in a simultaneous discrimination task. Because single pairs contained multiple redundant cues, whereas the relevant dimension was obvious only across stimulus pairs, the results revealed effects of both generalization and reversal learning. Accordingly, learning speed was enhanced for later discriminations. Experiment 2 tested the hens’ transfer performance to unknown pairs, following experience of 9 or 18 figure pairs. Four of seven hens showed reliable transfer after experience with 9 figures, but only three showed transfer after experience with 18 figures, indicating lower transfer with higher number of stimulus pairs learned. In experiment 3, hens were trained to discriminate 27 figure pairs. Discrimination ratios further decreased and the groups of pairs differed significantly in their ratios of discrimination. Individual hens’ pecking behaviour was analysed in relation to each dimension of single figures and in relation to relative differences in the levels of dimensions between paired figures. Hens were shown to be oriented towards irrelevant information and more towards relational and configurational than elemental and dimensional aspects. The results are discussed in the biological context of individual recognition in chickens’ dominance hierarchies, in which we suppose that chickens identify individual flock mates by representation of their visual pattern rather than by single characteristics. Received: 18 September 1998 / Accepted after revision: 23 December 1998