The Geometry of Stimulus Control

Many studies, both in ethology and comparative psychology, have shown that animals react to modifications of familiar stimuli. This phenomenon is often referred to as generalisation. Most modifications lead to a decrease in responding, but to certain new stimuli an increase in responding is observed. This holds for both innate and learned behaviour. Here we propose a heuristic approach to stimulus control, or stimulus selection, with the aim of explaining these phenomena. The model has two key elements. First, we choose the receptor level as the fundamental stimulus space. Each stimulus is represented as the pattern of activation it induces in sense organs. Second, in this space we introduce a simple measure of `similarity' between stimuli by calculating how activation patterns overlap. The main advantage we recognise in this approach is that the generalisation of acquired responses emerges from a few simple principles which are grounded in the recognition of how animals actually perceive stimuli. Many traditional problems that face theories of stimulus control (e.g. the Spence-Hull theory of gradient interaction or ethological theories of stimulus summation) do not arise in the present framework. These problems include the amount of generalisation along different dimensions, peak-shift phenomena (with respect to both positive and negative shifts), intensity generalisation, and generalisation after conditioning on two positive stimuli

Artificial neural networks as models of stimulus control

We evaluate the ability of artificial neural network models (multi-layer perceptrons) to predict stimulus-­response relationships. A variety of empirical results are considered, such as generalization, peak-shift (supernormality) and stimulus intensity effects. The networks were trained on the same tasks as the animals in the considered experiments. The subsequent generalization tests on the networks showed that the model replicates correctly the empirical results. It is concluded that these models are valuable tools in the study of animal behaviour

Chickens prefer beautiful humans

We trained chickens to react to an average human female face but not to an average male face (or vice-versa). In a subsequent test, the animals showed preferences for faces consistent with human sexual preferences (obtained from university students). This suggests that human preferences arise from general properties of nervous systems, rather than from face-specific adaptations. We discuss this result in the light of current debate on the meaning of sexual signals, and suggest further tests of existing hypotheses about the origin of sexual preferences

Cultural evolution developing its own rules: The rise of conservatism and persuasion

In the human sciences, cultural evolution is often viewed as an autonomous process free of genetic influence. A question that follows is, If culture is not influenced by genes, can it take any path? Employing a simple mathematical model of cultural transmission in which individuals may copy each other's traits, we show that cultural evolution favors individuals who are weakly influenced by others and able to influence others. The model suggests that the cultural evolution of rules of cultural transmission tends to create populations that evolve rapidly toward conservatism, and that bias in cultural transmission may result purely from cultural dynamics. Freedom from genetic influence is not freedom to take any direction

Discrete conventional signalling of a continuous variable

In aggressive interactions, animals often use a discrete set of signals, while the properties being signalled are likely to be continuous, for example fighting ability or value of victory. Here we investigate a particular model of fighting which allows for conventional signalling of subjective resource value to occur. The result shows that neither perfect nor no signalling are evolutionarily stable strategies (ESSs) in the model. Instead, we find ESSs in which partial information is communicated, with discrete displays signalling a range of values rather than a precise one. The result also indicates that communication should be more precise in conflicts over small resources. Signalling strategies can exist in fighting because of the common interest in avoiding injuries, but communication is likely to be limited because of the fundamental conflict over the resource. Our results reflect a compromise between these two factors. Data allowing for a thorough test of the model are lacking; however, existing data seem consistent with the obtained theoretical results

Spectacular pehnomena and limits to rationality in genetic and cultural evolution

In studies of both animal and human behaviour, game theory is used as a tool for understanding strategies that appear in interactions between individuals. Game theory focuses on adaptive behaviour, which can be attained only at evolutionary equilibrium. Here we suggest that behaviour appearing during interactions is often outside the scope of such analysis. In many types of interaction, conflicts of interest exist between players, fueling the evolution of manipulative strategies. Such strategies evolve out of equilibrium, commonly appearing as spectacular morphology or behaviour with obscure meaning, to which other players may react in non-adaptive, irrational way approach, and outline the conditions in which evolutionary equilibria cannot be maintained. Evidence from studies of biological interactions seems to support the view that behaviour is often not at equilibrium. This also appears to be the case for many human cultural traits, which have spread rapidly despite the fact that they have a negative influence on reproduction

Critiquing and Evaluating Law Students\u27 Writing: Advice from Thirty-Five Experts

While there are some differences of opinion about what is the best way to comment on and grade law students\u27 writing, a consensus seems to be developing based on the experience and insights of those in the profession who have done the job the longest and survived to tell about it. To help articulate this consensus, I selected thirty-seven experienced legal writing professors and asked them to respond to a questionnaire about critiquing and evaluating law students\u27 writing. My goal was to gather and record their wisdom, insights, and experience for other legal writing professors, particularly those who are new to the field

Unlocking the Secrets of Highly Successful Legal Writing Students

Why are some law students successful in their legal writing classes and others are not? To identify the secrets to success, Professor Enquist did a case study of six second-year law students as they wrote a motion brief and an appellate brief for their 2L legal writing course. Based on their 1L legal writing course, two of these students were predicted to be highly successful, two were predicted to be moderately successfully, and two were predicted to be only marginally successful. Through daily records of all their activities related to writing the briefs, interviews with the study subjects, drafts of their two brief projects, and their professor\u27s critiques of their work, the study reveals not only the results of working harder but the specifics of working smarter. The secrets to working smarter included note-taking and note-reviewing strategies; how to divide one\u27s time between researching, drafting, revising, editing, and proofreading; how to research and read cases efficiently; strategies for efficient time management; techniques for organizing one\u27s research and staying organized while writing; and accessing the professor as a primary resource. Pitfalls to avoid included procrastination, poor management of distractions, and scapegoating