Educating both halves of the brain: Educational breakthrough or neuromythology?

The increasing popularity of the idea that the two hemispheres of the human cerebral cortex carry on different modes of thinking has resulted in an accelerating social and commercial pressure to organize school curricula, teaching, and testing to conform to a right brain-left brain dichotomy. Evidence gathered from commissurotomy (split-brain) patients and right hemisphere studies on normal intact humans is reviewed and evaluated. Conclusions from this review are (a) the commissurotomy patients are not a suitable group on which to base generalizations about cortical functioning in the normal intact human; (b) the right-left hemisphere differences reported in many experiments on normal subjects are small and can be found only in an extremely narrow experimental context; and (c) there is no scientific basis in this work for any reorganization of curricular, teaching, or testing programs within contemporary educational practice.     

Effects of instructions and biofeedback on EEG-alpha production and the effects of EEG-alpha biofeedback training for controlling arousal in a subsequent stressful situation

In Phase One, 44 subjects participated in a 2 (instructions to increase alpha, no instructions to increase alpha) × 2 (alpha biofeedback, no alpha biofeedback) factorial experiment. Results indicated that increases in alpha production were due to instructions to increase alpha and that biofeedback had no effect on alpha production. In Phase Two, the 44 subjects from Phase One were exposed to a threat of shock whereas 11 additional subjects in a control condition were not. The design employed in Phase Two was a 2 (previous instructions and stress, no previous instructions and stress) × 2 (previous biofeedback and stress, no previous biofeedback and stress) plus 1 (no previous instructions/no previous biofeedback, no stress). Results indicated that the threat of shock was effective in increasing arousal (as measured by heart rate and skin resistance) but previous EEG-alpha biofeedback training was not effective in helping subjects decrease arousal while in the stressful situation. The results indicate that it is the instructions (and related information concerning alpha) rather than the biofeedback that is critical in alpha biofeedback training and that this training does not appear to have utility for controlling arousal under stress.     

Conditions on rate normalization in speech perception

Recent work by Summerfield (1975) and others indicates that a listener’s phonemic judgments may vary with the utterance rate of prior context. In particular, if a phonemic distinction is signaled by a temporal cue such as voice onset time (VOT), faster utterance rates tend to shift the phoneme boundary toward smaller values of that cue. The listener thus appears to “normalize” temporal cues according to utterance rate. In the present experiment, subjects identified syllables varying in VOT ([ga]-[k^ha]) following either a slow or a fast version of the phrase “Teddy hears_ _ _ _ .” Typical normalization effects were observed when the precursor phrase and target syllable had formant frequencies corresponding to an adult male vocal tract. However, a reversal of the typical pattern (i.e., a shift in the perceived voicing boundary towardlarger values of VOT with an increased utterance rate) occurred when the precursor and target had formant frequencies corresponding to an adult female vocal tract. Both normalization and “reverse” normalization effects were reduced or eliminated under several conditions of source change between precursor and target. These conditions included a change in fundamental frequency, a change in implied vocal-tract size (as reflected in an upward or downward scaling of formant frequencies), or both.     

Effects of displacing aggression by annoyed and nonannoyed subjects

Low hostility-guilt subjects were either annoyed or not annoyed by an experimental confederate and given the opportunity to (a) displace aggression against a second confederate in a memory task, (b) go through a similar task but not aggress, or (c) sit quietly for a comparable period of time. All subjects were subsequently allowed to aggress against their annoyer in a “creativity” task. While displacement following annoyance did not reduce physiological arousal, it did reduce the amount of subsequent aggression against the annoyer. Conversely, the expression of aggression in subjects who were not annoyed resulted in an increase in physiological arousal, but not in subsequent aggression. No significant relationships were found between physiological arousal and subsequent aggression.     

Cross‐cultural similarities and differences in the theoretical predictors of cyberbullying perpetration: Results from a seven‐country study

The Barlett Gentile cyberbullying model (BGCM) posits that correlated anonymity perceptions and the belief in the irrelevance of muscularity for online bullying (BIMOB) predict positive cyberbullying attitudes to predict subsequent cyberbullying perpetration. Much research has shown the BGCM to be the only published theory that differentiates traditional and cyberbullying while validly predicting cyberbullying. So far, however, the cross‐cultural ubiquity has gone understudied. Thus, 1,592 adult participants across seven countries (USA, Australia, Brazil, China, Germany, Japan, and Singapore) completed measures germane to the BGCM. Supporting the BGCM, the variables were significantly correlated for the entire sample, participants from independent cultures, and participants from interdependent cultures. However, the relationship between BIMOB and positive cyberbullying attitudes as well as the relationship between positive cyberbullying attitudes and cyberbullying perpetration were stronger for independent cultures. These results suggest that the BGCM postulates are mostly universal, but several relations appear to be culturally different. Theoretical implications are discussed.     

A Pilot Study Assessing the Relationship Between Child Harming Thoughts and Postpartum Depression

This pilot study explored relationships between postpartum mood and child harming thoughts. Fifty mothers from an outpatient pediatric office completed the Edinburgh Postnatal Depression Scale (EPDS), Postpartum Depression Predictors Inventory-Revised (PDPI-R), and Beck Anxiety Inventory (BAI). Participants also completed the Child Thoughts Inventory (CTI), a modified version of the Yale-Brown Obsessive-Compulsive Inventory (Y-BOCS) and Florida Obsessive-Compulsive Inventory (FOCI). Results indicated significant positive correlations between postpartum depression and anxiety and frequency and intensity of child harming thoughts. In addition, having a poor self-view was significantly correlated with intensity of child harming thoughts and previous anxiety was correlated with both frequency and intensity of child harming thoughts. Despite the fact that mothers experiencing postpartum mood disturbances rarely harm their infants the findings of this pilot study suggest that these women may have frequent and intense ego-dystonic thoughts about harming their children. Results also suggest that postpartum depression and anxiety may share similar cognitive processes.     

Self-projection and the brain

When thinking about the future or the upcoming actions of another person, we mentally project ourselves into that alternative situation. Accumulating data suggest that envisioning the future (prospection), remembering the past, conceiving the viewpoint of others (theory of mind) and possibly some forms of navigation reflect the workings of the same core brain network. These abilities emerge at a similar age and share a common functional anatomy that includes frontal and medial temporal systems that are traditionally associated with planning, episodic memory and default (passive) cognitive states. We speculate that these abilities, most often studied as distinct, rely on a common set of processes by which past experiences are used adaptively to imagine perspectives and events beyond those that emerge from the immediate environment.     

Perception of rhythmic grouping: testing the iambic/trochaic law

This study was designed to test the iambic/trochaic law, which claims that elements contrasting in duration naturally form rhythmic groupings with final prominence, whereas elements contrasting in intensity form groupings with initial prominence. It was also designed to evaluate whether the iambic/trochaic law describes general auditory biases, or whether rhythmic grouping is speech or language specific. In two experiments, listeners were presented with sequences of alternating /ga/ syllables or square wave segments that varied in either duration or intensity and were asked to indicate whether they heard a trochaic (i.e., strong-weak) or an iambic (i.e., weak-strong) rhythmic pattern. Experiment 1 provided a validation of the iambic/trochaic law in English-speaking listeners; for both speech and nonspeech stimuli, variations in duration resulted in iambic grouping, whereas variations in intensity resulted in trochaic grouping. In Experiment 2, no significant differences were found between the rhythmic-grouping performances of English- and French-speaking listeners. The speech/ nonspeech and cross-language parallels suggest that the perception of linguistic rhythm relies largely on general auditory mechanisms. The applicability of the iambic/trochaic law to speech segmentation is discussed.