Two discrimination test apparatuses for primates

This paper describes two test apparatuses developed to facilitate discrimination learning studies with primates. The semiautomated apparatus provides for presentation of stereometric stimulus materials through the illumination of lamps which make a one-way mirror transparent at the onset of a trial. The totally automated test system was developed to facilitate the collection of Transfer Index (TI) measurements, measurements intended to provide for equitable assessments of the learning-set capabilities of diverse primate genera. The TI test procedures and the system’s operations provide for criterional mastery (67% or 84% responses correct) of two-ehoice visual discrimination problems, consisting of projected patterns, then reversal of cues for the 10 test trials that are of particular significance in calculation of the TI scores.     

Letter versus dot stimuli as tools for “splitting the normal brain with reaction time”

Filbey and Gazzaniga (1969) found simple dot-present or -absent reports averaged 35 ms slower for the left than for the right visual field. Other data suggests that verbal processing efficiency differences between the cerebral hemispheres, rather than transcallosal transfer time alone, must be tapped to obtain half-field differences as large as 35 ms. Three experiments were conducted. The first failed to show any half-field differences in vocal RT for dot detection; the second replicated previous reports of significant right field superiority of vocal RT to letter stimuli for right handers, and also showed a substantially smaller half-field difference for left handers; the third experiment, utilizing the fixation control procedure of the second experiment, again failed to show half-field differences for the dot detection paradigm. Differences between the Filbey and Gazzaniga and present results probably reflect important procedural differences. We conclude that transcallosal transfer time for simple dot information is much smaller than assumed by Filbey and Gazzaniga and that the letter report-time task taps hemispheric asymmetries of verbal processing efficiency.     

WONDER AND UNDERSTANDING

Abstract. Wonder is a root of the religious experience, and the desire to understand drives science. If wonder and understanding are fundamentally opposed, religion and science will be also. But only if wonder is limited to the contemplation of magic or mysteries is religion in principle opposed to science. The aim of science is to explain how something is possible. Understanding how something is possible need not destroy our wonder at it. Recent scientific theories of the human mind—albeit based in computer technology—increase our wonder at its richness and power.     

Serial position and clustering effects in a chimpanzee’s “flee recall”

Lana, a chimpanzee sophisticated in the language Yerkish, was tested for free recall on lists consisting of from one to eight words randomly drawn from one of three taxonomic categories or on lists consisting of nine words with every third word from a different category. Serial position effects were observed for the four- to eight-item lists, with statistically significant first-item primacy effects on the seven- and eight-word lists and last~position recency effects on the six-, seven-, and eight-word lists. Also, above-chance clustering was observed in the recall of the nine-item categorized lists. These results were compared and contrasted with the serial position and clustering effects obtained in free recall with humans. Several alternative theoretical accounts of the results were considered.     

‘The threat of the Other’: Using mixed quantitative and qualitative methods to elucidate racial and cultural dynamics in the counselling process

This paper examines the use of mixed quantitative and qualitative methods in the study of racial and cultural dynamics in the counselling process. The approach is illustrated by the author's own research which combined quantitative survey instruments with a blend of qualitative methods. Emphasis is given to complex racial and cultural phenomena arising from the qualitative methods of data collection and data analysis, particularly the pervasive experience of ‘threat of the Other’. These phenomena were seen to permeate the counselling interactions both explicitly and implicitly. The emerging racial dynamics are discussed with reference to theoretical concepts which stress the interrelationship between intrapsychic development and sociopolitical issues. The effectiveness of employing pluralistic methods in this field of enquiry is also evaluated.     

Explaining Gender Differences in Responses to Supportive Messages: Two Tests of a Dual-Process Approach

We propose a comprehensive explanation for gender differences in responses to supportive communication grounded in a dual-process theory of communication outcomes. Two studies confirmed consistent gender differences in responses by US college students to supportive communication and assessed the mediating effects of an ability factor (cognitive complexity) and two motivational factors (expressive and instrumental orientations) on situation elaboration and message evaluation. Study 1 focused on everyday comforting contexts (N?=?318), whereas Study 2 focused on bereavement (N?=?103). Both studies found that cognitive complexity mediated gender differences in situation elaboration and further found that cognitive complexity and expressive orientation collectively mediated gender differences in evaluative responses to supportive messages. Theoretical and pragmatic implications of the results are discussed.     

Change in action: how infants learn to walk down slopes

A critical aspect of perception–action coupling is the ability to modify ongoing actions in accordance with variations in the environment. Infants’ ability to modify their gait patterns to walk down shallow and steep slopes was examined at three nested time scales. Across sessions, a microgenetic training design showed rapid improvements after the first session in infants receiving concentrated practice walking down slopes and in infants in a control group who were tested only at the beginning and end of the study. Within sessions, analyses across easy and challenging slope angles showed that infants used a ‘braking strategy’ to curb increases in walking speed across increasingly steeper slopes. Within trials, comparisons of infants’ gait modifications before and after stepping over the brink of the slopes showed that the braking strategy was planned prospectively. Findings illustrate how observing change in action provides important insights into the process of skill acquisition.