Norm-of-reaction: definition and misinterpretation of animal research

The development of a phenotype is due to an interaction of the genotype with the environment. Two terms have been used to describe the outcome of this interaction, the norm-of-reaction and the reaction range. The first represents the theoretically limitless distribution of the phenotypes that may be expressed by a given genotype. The reaction range implies an upper and lower limit for phenotype expression possible from a given genotype. A critical distinction between the reaction range and the norm-of-reaction is that the norm-of-reaction is a statement of the conceivable interactions found but does not imply any predictability other than that within the conditions previously tested experimentally, that is, the tails of a normal distribution are infinitely variable, whereas the concept of reaction range implies a limitation inherent in the genotype, that is, a finite range. Empirical support for the reaction-range concept is questionable. Animal studies cited in support of the reaction range have been inappropriately and incorrectly interpreted.     

Transgenesis in animal systems: a view from within

The introduction of 'foreign' or altered genes into animals arouses both scientific and public concern. So too does any extension of this practice to human beings at the somatic (tissue) level, let alone interference in the human germ line (genetic material passed on to future generations). The range of possible genetic modifications, both those in progress and those likely in the near future, is so vast as to make a uniform Christian response untenable. As with other technologies, there are both laudable and dubious uses for genetic engineering in animal systems; it is neither an unmixed blessing nor an unmitigated curse. It is argued that Christians should engage with these issues on a case-by-case basis, giving due weight to the possible risks and concomitant suffering for the animals used, but basing our ultimate approval or disapproval on the congruence of means and aims with those evinced by Jesus in his ministry of healing, teaching and reconciliation.     

Scalar properties in animal timing: Conformity and violations

The article reviews data from animal subjects on a range of timing tasks (including fixed-interval and temporal differentiation schedules, stimulus timing, aversive conditioning, and Pavlovian methods) with respect to conformity to the two scalar properties of timing behaviour: mean accuracy and scalar (Weberian) variance. Systematic deviations were found in data from temporal differentiation schedules, timing of very short (<100 ms) or very long (>100 s) durations, effects of “task difficulty”, and some special cases where circadian and interval timing seemed to interact, or where some specific durations seemed to be timed more precisely than others. Theoretical reconciliation of some of these deviations with underlying scalar timing can be achieved, but a number of problematical cases remain unexplained.     

Scalar properties in animal timing: conformity and violations

The article reviews data from animal subjects on a range of timing tasks (including fixed-interval and temporal differentiation schedules, stimulus timing, aversive conditioning, and Pavlovian methods) with respect to conformity to the two scalar properties of timing behaviour: mean accuracy and scalar (Weberian) variance. Systematic deviations were found in data from temporal differentiation schedules, timing of very short (<100 ms) or very long (>100 s) durations, effects of "task difficulty", and some special cases where circadian and interval timing seemed to interact, or where some specific durations seemed to be timed more precisely than others. Theoretical reconciliation of some of these deviations with underlying scalar timing can be achieved, but a number of problematical cases remain unexplained.     

The representative animal

The anthropocentric approach to the study of animal behavior uses representative nonhuman animals to understand human behavior. This approach raises problems concerning the comparison of the behavior of two different species. The datum of behavior analysis is the behavior of humans and representative animal phenotypes. The behavioral phenotype is the product of the ontogeny and phylogeny of each species, and this requires that contributions of genotype as well as behavioral history to experimental performance be considered. Behavior analysis tends to favor the ontogenetic over the phylogenetic component, yet both components are responsible for the performance of each individual animal. This paper raises questions about the role of genotype variables in the use of representative animals to understand human behavior. Examples indicating the role of genotype in human behavior are also discussed. The final section of the paper deals with considerations of genotype in the design of animal experiments.     

Image analysis of small animal feeding behavior: An update

Recently we published a design for an automated feeding behavior system (Rowley, Stitt, & Hanson, 2003). One disadvantage of this system is that it relied on expensive, custom hardware. Here we present a modified version that replaces the custom hardware with a simple, commercially available webcam and modified the MATLAB analysis software as well. The new system is much less expensive and easier to implement, while still providing for bias-free collection of consumption data in a feeding behavior trial.     

Cognitive bias in animal behavior science: a philosophical perspective

Animal Cognition - Emotional states of animals influence their cognitive processes as well as their behavior. Assessing emotional states is important for animal welfare science as well as for many...     

Phobic dimensions: IV. The structure of animal fears

Research designed to determine the number and kind of dimensions underlying self-reports of animal fears is relatively rare. To contribute further knowledge to this area of study, Davey's methodology [Davey, G. C. L. (1994a). Self-reported fears to common indigenous animals in an adult UK population: the role of disgust sensitivity. British Journal of Psychology, 85, 541-554.] was improved. Principal components analysis with Varimax rotation of the self-ratings to items of Davey's Animal Fears Questionnaire returned by Ss from a Dutch community sample (N = 214) revealed four reliable, relatively independent dimensions: (1) fear-relevant animals, (2) dry or non-slimy invertebrates, (3) slimy or wet looking animals and (4) farm animals. Replicating Davey (1994a), females, relative to males, reported higher levels on most fear items. Principal components analysis with Oblimin rotation involving animal fears scales (derived from the dimensions identified in the present study), dimensions of non-animal fears, disgust sensitivity, sex-role orientation and the major dimensions of personality from the Eysenckian system revealed 4 higher-order factors, namely specific animals fears, positive affectivity, toughmindedness and negative affectivity. At an even higher level, these 4 higher-order factors merged into two factors: (1) a bipolar positive affectivity versus neuroticism/general emotionality/negative affectivity factor and (2) a toughmindedness dimension. Studies such as these contribute in helping provide the elements of the hierarchical model of fears proposed by Taylor [Taylor, S. (1998). The hierarchic structure of fears. Behaviour Research and Therapy, 36, 205-214.]. Findings across different studies suggest that there are at least 5 first-order dimensions of animal fears, the above 4 and predatory (fierce) animals, that may be included in such a model.     

Auditory evoked response in chinchilla: Application to animal audiometry

In chinchilla a neural response to tone pips or the onset of pure tones can be recorded from scalp electrodes. If 64 responses are averaged by a computer the response can be recognized reliably at sound pressure levels at or near chinchilla’s usual behavioral thresholds of hearing. Detection is possible at slightly lower levels if the number of responses is increased to 500 to 1000. The response is an initiallypositive diphasic wave with latency to foot between 1.6 and 4.0 msec. It apparently arises from several structures in the brainstem but chiefly from the inferior colliculus. The technique may be useful in assessing quickly the sensitivity of the peripheral auditory mechanism in small laboratory animals.     

Probabilistic contingency theories of animal conditioning: A critical analysis

Seven contingency theories of classical and instrumental conditioning were defined in relation to the contingency matrix and to six separate probabilities which can be derived from this matrix. These theories were compared on the basis of formal similarities and differences, and were judged against three separate empirical variables which have been discussed in the contingency literature: the duration of the intertrial interval, partial reinforcement, and negative contingencies between the two events of conditioning. All previous theories had some difficulty predicting the effects of one or more of these variables upon animal conditioning. Also, some formulas make the unusual prediction that there will be less conditioning when there is more than one conditioning trial. The paper concluded with an extensive discussion of the problems that are created by conditioning events with temporal extension; events which are then categorized by a contingency matrix which has no temporal character. Some possible solutions to the problems were discussed.     

When danger lurks in the background: attentional capture by animal fear-relevant distractors is specific and selectively enhanced by animal fear

Across 2 experiments, a new experimental procedure was used to investigate attentional capture by animal fear-relevant stimuli. In Experiment 1 (N=34), unselected participants were slower to detect a neutral target animal in the presence of a spider than a cockroach distractor and in the presence of a snake than a large lizard distractor. This result confirms that phylogenetically fear-relevant animals capture attention specifically and to a larger extent than do non-fear-relevant animals. In Experiment 2 (N=86), detection of a neutral target animal was slowed more in the presence of a feared fear-relevant distractor (e.g., a snake for snake-fearful participants) than in presence of a not-feared fear-relevant distractor (e.g., a spider for snake-fearful participants). These results indicate preferential attentional capture that is specific to phylogenetically fear-relevant stimuli and is selectively enhanced in individuals who fear these animals.     

God and animal pain

It seems that animal pain is an obstacle to belief in a good God, though Christianity has not been much concerned with the issue. A systemic approach to pain is not a complete answer, nor is there any merit in denying that God is subject to moral appraisal. Marilyn McCord Adams recommends that such investigations be located in the specifics of a religious tradition. Her advice eliminates a couple of radical solutions but there appear to be a number of ways in which progress might be made without doing violence to the tradition that is in need of a theodicy.