VISUAL AND TACTUAL EXPLORATION IN RATS REARED IN DIFFERENT DEGREES OF VISUAL AND TACTUAL STIMULATION

NIELSEN, T. C. Visual and tactual exploration in rats reared in different degrees of visual and tactual stimulation. Scand. J. Psychol. , 1971, 12, 53–61. – Four groups of eight rats each were reared in the four possible combinations of high and low visual and high and low tactual stimulation. Early tactual enrichment increased later tactual exploration regardless of visual stimulation. Visual enrichment did not influence exploration in the tactual enrichment groups, but in the tactual deprivation groups it seemed to produce more visual and less tactual exploration. The most deprived group exhibited a high locomotor activity which could not be explained in terms of an increased tendency to explore.     

Psychosocial aspects of truancy in early adolescence.

The authors studied truancy in junior high school students, largely by structured interviews of 33 truants. Truancy at this age was commonly associated with significant difficulties at home, at school and with peers. Two modal types of truants were delineated: "authority defying" and "peer phobic." The school environment, including the response to truancy and the transition to the junior high, was found to play a critical role in creating and aggravating truancy. The authors discuss the findings with respect to strategies for prevention and remediation.     

Let's Suspend Suspensions: Consequences and Alternatives

National data dispute the value of school suspensions. This article describes specific alternatives to suspension, with special attention devoted to the creation of “in-school” suspension programs. It outlines the philosophies, benefits, essential components, and major difficulties of in-school suspension centers. The author discusses truancy prevention, contingency contracting, and corporal punishment, and provides sources for obtaining detailed information on each disciplinary technique.     

Imitation recognition in a captive chimpanzee (Pan troglodytes)

This study investigated the ability of a captive chimpanzee (Pan troglodytes) to recognise when he is being imitated. In the experimental condition of test 1a, an experimenter imitated the postures and behaviours of the chimpanzee as they were being displayed. In three control conditions the same experimenter exhibited (1) actions that were contingent on, but different from, the actions of the chimpanzee, (2) actions that were not contingent on, and different from, the actions of the chimpanzee, or (3) no action at all. The chimpanzee showed more "testing" sequences (i.e., systematically varying his actions while oriented to the imitating experimenter) and more repetitive behaviour when he was being imitated, than when he was not. This finding was replicated 4 months later in test 1b. When the experimenter repeated the same actions she displayed in the experimental condition of test 1a back to the chimpanzee in test 2, these actions now did not elicit those same testing sequences or repetitive behaviours. However, a live imitation condition did. Together these results provide the first evidence of imitation recognition in a nonhuman animal.     

Variation in cortical evoked responses as a function of performance criterion

Averaged evoked cortical responses (CER) from the scalp of human Ss were recorded within an experimental paradigm that permitted the performance criterion to be varied. The signals evoking the cortical responses were contingent upon S’s pressing a button to bisect a temporal interval within certain tolerance limits. Under passive conditions averaged response waveforms lacked a second, late component that became prominent under temporal bisection conditions. The late component P² - N² increased regularly in magnitude as the performance criterion was made more stringent. The effect of performance criterion on the earlier component, N¹ - P², was neither as large nor as systematic as that shown by P² - N².     

VOLITIONAL ASPECTS OF VOICE PERFORMANCE: AN EXPERIMENTAL APPROACH

The subjects (all females) were instructed to hold a certain note. In some of the trials an alien (female) voice with a continuously falling or rising frequency unexpectedly replaced the subject's own voice as the auditory stimulus in her headphone. Most of the subjects took the alien voice as their own and experienced a complete lack of volitional control over their own voice. A compensatory behaviour was found; when the subjects tried to hold the note the frequency of their voices went in the opposite direction to the frequency of the alien voice.     

Interhemispheric EEG coherence during sleep and wakefulness in left- and right-handed subjects

REM sleep is associated with the production of complex imagery sequences. Yet research is divided as to whether different brain regions are more or less coordinated in their functioning at this time. Some research suggests that there may occur a functional disconnection of the left and right cerebral hemispheres during REM sleep which is similar to the disconnection syndrome seen after corpus callosotomy. Other research suggests that an increase in interhemispheric coordination occurs. On the assumption that hemispheric coordination is reflected in the EEG coherence measure, we explored differences in interhemispheric coherence recorded in six left- and six right-handed normal subjects during periods of wakefulness, stage REM, stage 2, and stage 3/4 sleep. Strong evidence was found that mean EEG coherence values are larger during sleep than during waking and that they are approximately equal for the different stages of sleep. Frontal electrode placements demonstrated a slightly different pattern of coherence than central, parietal, or occipital placements. Furthermore, coherence values were larger for left-handed subjects over the occipital region during wakefulness, stage 2, and stage REM sleep, but not during stage 3/4 sleep. Coherence was not different for male and female subjects. These findings oppose the interpretation that a functional disconnection of hemispheres occurs during REM sleep and favor the interpretation that sleep in general is a state of heightened cortical coordination. Moreover, greater interhemispheric coherence over occipital brain regions in left-handed subjects suggests possible differences in the cognitive processes of these subjects during waking and dreaming states.     

An electrophysiological investigation into the automaticity of emotional face processing in high versus low trait anxious individuals

To examine the extent of automaticity of emotional face processing in high versus low trait anxious participants, event-related potentials (ERPs) were recorded to emotional (fearful, happy) and neutral faces under varying task demands (low load, high load). Results showed that perceptual encoding of emotional faces, as reflected in P1 and early posterior negativity components, was unaffected by the availability of processing resources. In contrast, the postperceptual registration and storage of emotion-related information, as reflected in the late positive potential component at frontal locations, was influenced by the availability of processing resources, and this effect was further modulated by level of trait anxiety. Specifically, frontal ERP augmentations to emotional faces were eliminated in the more demanding task for low trait anxious participants, whereas ERP enhancements to emotional faces were unaffected by task load in high trait anxious participants. This result suggests greater automaticity in processing affective information in high trait anxious participants.     

Language evolution: consensus and controversies

Why is language the way it is? How did language come to be this way? And why is our species alone in having complex language? These are old unsolved questions that have seen a renaissance in the dramatic recent growth in research being published on the origins and evolution of human language. This review provides a broad overview of some of the important current work in this area. We highlight new methodologies (such as computational modeling), emerging points of consensus (such as the importance of pre-adaptation), and the major remaining controversies (such as gestural origins of language). We also discuss why language evolution is such a difficult problem, and suggest probable directions research may take in the near future.