The Effects of Hippocampal and Area Parahippocampalis Lesions in Pigeons: II. Concurrent Discrimination and Spatial Memory

Two experiments were conducted to examine the effects of bilateral hippocampus (Hp) and area parahippocampalis (APH) lesions in pigeons on the acquisition of a visual and spatial task. In Experiment 1, pigeons were trained on three successive six-pair concurrent discrimination tasks, each using a novel set of stimuli. There was no difference between control unoperated pigeons and Hp-APH pigeons in terms of the number of sessions required to learn either the first, second, or third concurrent discrimination task. In Experiment 2, the same pigeons were trained on an open-field spatial task similar in many ways to the radial-arm maze task used with rats. In contrast to the absence of impairments on the visual concurrent discrimination task, pigeons with Hp-APH lesions were severely impaired on the acquisition of the spatial task. These findings support the view that the Hp-APH in pigeons is important for the processing of spatial, rather than visual information.     

Discrimination learning during the first year: stimulus and positional cues

In four studies, 3-, 6-, and 9-month-old human infants were tested in a discrimination learning task in which visual fixation to a particular stimulus or lateral position was reinforced with an auditory stimulus. In Experiment 1, all age groups exhibited acquisition, extinction, and reinstatement of fixation to the reinforced target or position. Experiment 2 revealed that 3-month-olds retained the positional discrimination but not the stimulus discrimination after a 5-min delay between acquisition and extinction; older infants retained both types of discriminations. In Experiments 3 and 4 we investigated a possible developmental shift in the dominance of positional versus stimulus cues by training infants on displays in which stimulus and position were confounded and then by dissociating the cues on test trials. Results from both experiments indicated positional cue dominance for young infants and stimulus cue dominance for older infants. The findings are discussed in terms of differences in the attentional demands elicited by proprioceptive versus exteroceptive cues.     

The new technology and its human impact

In the years that have passed since publication of the Club of Rome's seminal report “Limits to Growth,” the issues raised in terms of development, resource use and the environment have become ever more pressing. The potential of advances in science and technology to affect all aspects of life, including development, was then little understood. Today's unparalleled burst in scientific and technological creativity has given new options and opportunities to the world economic system.

Central to this process is a series of concepts which includes the scientification of technology, by which technology is increasingly generated and developed on scientific bases, the breaking down of interdisciplinary barriers and mankind's new found capacity literally to invent resources, leading to the emergence of whole categories of new materials. These changes make possible a new approach to economic growth, relying on decentralization and flexibility and the selection of technology mixes best suited to different socio‐economic and cultural contexts. In parallel, the key importance above all of the information technologies is producing a dematerialization of goods, a trend exemplified by the shift from product oriented to function oriented industries.

The new technologies of the 1980s are cross‐fertilizing and self‐disseminative. They are creating an exceptional number of innovative options in processes, products, services, organization and markets. Mature industrial sectors can undergo a process of rejuvenation to recover competitiveness by the grafting of advanced technologies onto traditional activities. The results are already evident in industrialized countries, such as Italy. The flexibility offered by the new technologies offers perhaps our best hope for a solution to the widening gap between rich and poor nations, contrary to the belief that identifies in advances in science and technology the seeds of a process of polarization dividing the world.

The countries of the United States, Japan and Western Europe—the so‐called Triad Power—dominate the emerging technologies and their applications. In fact, given the pace of today's technological revolution, developing countries are effectively excluded from active participation in the process of technological change. New technologies are not “off the peg,” they have to be learned and controlled, to be introduced into an existing flexible system possessing trained manpower and an adequate capital base. Introduction into the Third World, where these essential conditions are frequently lacking, will not be a painless process. Technology transfer without adaptation is likely to have undesirable cultural and societal disadvantages.

North and South are simultaneously experiencing radically different processes of evolution: the former, through restructuring and innovation; the latter, through the drive for more quantitative growth. Continuing stress on quantitative growth carries with it the risk that other goals—environmental quality, even the eradication of poverty—may suffer. Here lies the possibility that unless economic patterns change, today's imbalance between the haves and the have nots may be perpetuated or even consolidated.

The countries of the North individually all face problems in addressing these issues. The international banking system is hamstrung with the problems of Third World debt. Primary producers no longer command high prices for their raw materials on world markets and so this source of development funding is also drying up. The need is therefore for a global approach. In each Third World situation, specific needs and requirements must be identified to be tackled via technology blending, whereby a mix of emerging and traditional technologies is selected to raise the quality of output to the levels now demanded by a sophisticated world economy.

Another important area is that of energy, together with the worsening environmental and even climatic effects of energy policies. The need is for a long term strategic view to marshall the contribution new technologies can make to improving the lot of mankind in full respect for his environment.

Technological change also implies societal change. In labor markets, labor mismatch creates pockets of employment which are difficult to eradicate. Yet, overall, the hope is that expanding economic horizons will create unlimited opportunities for new jobs and new skills. The key is education and training. A feed and feedback mechanism between education and the economy represents an intangible investment in the future.

Economic growth, technological innovation, development of culture and society, have always moved together with synergism. Current changes are not so much just physical as conceptual. We are passing from a mechanical (or mechanistic) society to one that can be termed cybernetic. Causality, sequentiality and hierarchy are giving way to a functional interdependence at a systems level. Greater participation will produce more opportunities for self‐fulfillment. As old social equilibria collapse, management of social change can be seen to be as important as management of technological change.

The technological revolution has deep roots in Western culture. It is a liberating force that can lead to greater cultural enrichment. By understanding the changes now underway, we can ensure that the new pattern of society that emerges from exploitation of the new technologies retains man at its center and so benefits the whole of humanity.     

Singing more,singing harsher: occurrence of nonlinear phenomena in a primate’ song

Animal Cognition - Nonlinear phenomena (NLP) in animal vocalizations arise from irregularities in the oscillation of the vocal folds. Various non-mutually exclusive hypotheses have been put forward...     

Exploring the effect of testing on forgetting in vocabulary learning: an examination of the bifurcation model

ABSTRACT

Research on the testing effect demonstrated a stronger decrease in performance for repeated studying compared to repeated testing. The bifurcation model attributes this test-delay interaction to different distributions of item memory strength. The present study tested the assumptions of the bifurcation model for learning foreign language vocabulary. We hypothesised an elimination or reduction of the interaction in a test/feedback condition because feedback prevents the bifurcation of item memory strength. Our experiment based on a 3 (Learning Method within: Test, test/feedback, copy)?×?3 (Retention Interval between: Immediate, 1-week, 2-weeks) mixed factorial design with a sample of N = 122. The greatest long-term retention was achieved in the test/feedback condition. The bifurcation model was supported by a reduced test-delay interaction for the test/feedback condition. Further evidence for the bifurcation model is needed as interpretations on the dropout rates of items with different recall success were limited due to a floor effect.