TEMPORAL INTEGRATION OF PERCEPTUAL RESPONSE TO SUPRALIMINAL ELECTRICAL STIMULATION

E kman , G., F röberg , J. & F rankenhaeuser , M. Temporal integration of perceptual response to supraliminal electrical stimulation. Scand. J. Psychol ., 1968, 9, 83–88.—The effect of duration of electrical stimulation on perceived unpleasantness was investigated in 10 subjects. Duration of stimulation ranged from 0.05 to 3.00 sec. Three levels of intensity were investigated representing 2, 3, and 4 times the individual sensation threshold. For all stimulus intensities perceived unpleasantness was a simple logarithmic function of stimulus duration over the whole temporal range. This relation describes the trend of both the group data and the data from most individual subjects. The results support previous findings over a narrower temporal range and agree with results recently obtained in several additional sense modalities.     

The High School Dropout Goes to College

662 former secondary school leavers of academic potential were identified for a program designed to give selected dropouts a chance to enter the University of Toledo. Following responses to questionnaires, 94 students were selected for further screening, which resulted in the final selection of 50 candidates. 34 members of the experimental group attended pre-school workshops in reading, writing, and study habit skills. 31 enrolled as regularly admitted students in academic programs of the university for the academic year. 11 completed their freshman year, although only 4 were making satisfactory academic progress.     

Effects of prolonged gravitational stress on performance

Effects of prolonged radial acceleration on performance were studied in eight series of experiments: (I) Visual choice reaction time, (II) Visual acuity, (III) Accuracy of movement, (IV) Perceptual speed, (V) The Stroop test, (VI) The 100 - 3 test, (VII) Multiplication and (VIII) Time perception.     

An investigation of trained neural networks from a neurophysiological perspective

The application of theoretical neural networks to preprocessed images was investigated with the aim of developing a computational recognition system. The neural networks were trained by means of a back-propagation algorithm, to respond selectively to computer-generated bars and edges. The receptive fields of the trained networks were then mapped, in terms of both their synaptic weights and their responses to spot stimuli. There was a direct relationship between the pattern of weights on the inputs to the hidden units (the units in the intermediate layer between the input and the output units), and their receptive field as mapped by spot stimuli. This relationship was not sustained at the level of the output units in that their spot-mapped responses failed to correspond either with the weights of the connections from the hidden units to the output units, or with a qualitative analysis of the networks. Part of this discrepancy may be ascribed to the output function used in the back-propagation algorithm.     

Brain mechanisms involved in angry prosody change detection in school-age children and adults,revealed by electrophysiology

Voices transmit social signals through speech and/or prosody. Emotional prosody conveys key information about the emotional state of a speaker and is thus a crucial cue that one has to detect in order to develop efficient social communication. Previous studies in adults reported different brain responses to emotional than to neutral prosodic deviancy. The aim of this study was to characterize such specific emotional deviancy effects in school-age children. The mismatch negativity (MMN) and P3a evoked potentials, reflecting automatic change detection and automatic attention orienting, respectively, were obtained for neutral and emotional angry deviants in both school-age children (n = 26) and adults (n = 14). Shorter latencies were found for emotional than for neutral preattentional responses in both groups. However, whereas this effect was observed on the MMN in adults, it appeared in an early discriminative negativity preceding the MMN in children. A smaller P3a amplitude was observed for the emotional than for the neutral deviants at all ages. Overall, the brain responses involved in specific emotional change processing are already present during childhood, but responses have not yet reached an adult pattern. We suggest that these processing differences might contribute to the known improvement of emotional prosody perception between childhood and adulthood.     

A Comprehensive Decision Approach for Rubber Tree Planting Management in Africa

The main objective of this study is to settle a rigorous field of decision analysis for rubber tree clones selection. Nowadays, there does not exist any process based upon a rigorous method to select the best clone to be plant in order to get the highest return on investment. The only known selection method is to use the experience of different protagonists acting in the plantation. So, we need a tool that takes into account very important criteria in order to achieve the main objective. This goal is achieved by using multicriterion analysis methods to the clone selection. The ranking procedure uses Elimination and Choice Expressing the Reality (ELECTRE III). For each criterion, indifference and preference thresholds are determined after establishing the relative importance of each criterion including rubber tapping, cumulative production during 15 years, cumulative production between 15 and 25 years, wind resistance, disease resistance, physiological resistance, grafting and quality of the rubber. Copyright © 2011 John Wiley & Sons, Ltd.     

Presence/absence-sample matching by pigeons: divergent retention functions may result from the similarity of behavior during the absence sample and the retention interval

Divergent choose-absence retention functions typically found in pigeons following presence/absence-sample matching have been attributed to the development of a single-code/default coding strategy. However, such effects may result from adventitious differential responding to the samples. In Experiment 1, retention functions were divergent only when differential sample responding could serve as the basis for comparison choice. In Experiment 2, when pecking did not occur during the retention interval, a choose-absence bias was found, but when pecking occurred during the retention interval, a choose-presence bias resulted. In Experiment 3, positive transfer was found when a stimulus associated with the absence of pecking replaced the absence sample but not when a stimulus associated with pecking replaced the presence sample. Thus, presence/absence-sample matching may not encourage the development of a single-code/default coding strategy in pigeons.     

The Ecological Self: Metaphor and Developmental Experience?

The term ecological self, used within the fields of deep ecology and ecopsychology, is considered here from the viewpoint of developmental research and theory, within the context of contemporary relational psychoanalysis. Both developmental theory and more specifically our concept of health are explored with the inclusion of relatedness to the nonhuman world and an emphasis on embodiment and interactive experience. Illustrations and examples are drawn from research, clinical work with adults and the literature of natural history.