The aha effect in groups and other dynamic learning contexts

The aha effect is a memory advantage for initially ambiguous stimuli (e.g., "The notes were sour because the seam split.") that are subsequently resolved ("Bagpipe") over stimuli that are comprehensible from the outset (see P M. Auble, J. J. Franks, & S. A. Soraci, 1979; T. W. Wills, S. A. Soraci, R. A. Chechile, & H. A. Taylor, 2000). The authors examined the influence of learning context on the aha effect by manipulating whether generative tasks were completed in a group setting or alone. In Experiment 1, participants in a group context either discussed difficult aha sentences, or overheard the discussion. In Experiments 2 and 3, lone participants were exposed to the sentences, and either spoke their thoughts aloud or thought silently. Participants in a group context did, as predicted, exhibit the aha global deletion of quotation marks effect. Moreover, in all experiments an aha effect was found for the active, speaking condition only. The authors discuss implications for generative learning and collaborative discourse processes.     

Psychometric properties and predictive validity of the Mt Scale of the MMPI-2

The College Maladjustment (Mt) Scale is a 41-item supplementary scale of the Minnesota Multiphasic Personality Inventory. It was designed to identify college students classified as maladjusted. Very little research has been conducted on the Mt Scale in the 40 years since its inception. The current study had the following four goals: (a) provide additional data on the internal consistency reliability, (b) examine the relationship between Mt Scale scores and various school-related domains, (c) examine the relationship between Mt scores and indices of distress (trauma exposure, post-traumatic stress disorder [PTSD] symptoms, and history of psychological treatment), and (d) examine the diagnostic accuracy of cutting scores across the full spectrum of possible scores using receiver operating characteristic (ROC) analyses. The Mt Scale is relatively internally consistent (alpha = .85). Elevations on the Mt Scale were significantly associated with lower current grade point average, arriving late to classes more often, the PTSD symptoms of avoidance and arousal, and a history of treatment. Last, the findings from the ROC analyses suggest that the previously obtained cutting scores of 15 and 22 are too low and that values of 29 or higher are more likely to yield the best diagnostic utility values.     

MMPI-2 personality profiles of high-functioning adults with autism spectrum disorders

The Minnesota Multiphasic Personality Inventory-Second Edition was administered to 20 adults with autism spectrum disorders (ASD) who fell in the average to above average range of intelligence and 24 age-, intelligence-, and gender-matched college students. Large group differences, with the ASD group scoring higher, were found on the L validity scale, Clinical Scales 2 (D) and 0 (Si), Content scale Social Discomfort (SOD), Supplementary scale Repression (R), and Personality Psychopathology Five (PSY-5) scale INTR (Introversion). The proportion of ASD adults scoring in the clinical range on these scales was between 25% and 35%. High scores on these scales are consistent with the clinical picture of Asperger syndrome and high-functioning autism in adulthood. Future directions and implications for identifying adults in need of a specialized autism assessment are discussed.     

Load-dependent modulation of affective picture processing

Because of the biological significance of emotional stimuli, their processing is considered largely automatic. In the study reported herein, we tested the alternative hypothesis—namely, that the processing of emotional stimuli requires some level of attention. Our experiments utilized highly negative and arousing visual stimuli comprising mutilated bodies. All experiments employed a single task, which consisted of determining whether two peripheral bars were like oriented or not, thereby eliminating potential task-difference confounds that may have contaminated prior studies. Our results revealed that task-irrelevant unpleasant images slowed reaction time during the performance of the main task. Such interference was modulated by task difficulty as well as by alcohol consumption, showing that the processing of emotional visual stimuli is not immune to attentional manipulations. These results suggest that it is essential to utilize attentional manipulations that more fully consume attentional resources in order to demonstrate that the processing of emotional stimuli is resource limited.     

Exploration and avoidance learning after ibotenic acid and radio frequency lesions in the rat amygdala

Open-field activity, avoidance behavior, and plasma corticosterone levels were studied after intraamygdala injections of 3.0 micrograms ibotenic acid (IBO) and radio-frequency (RF) lesions in the amygdala complex of male Wistar rats. The experiments were undertaken to evaluate the importance of amygdala neurons versus axons of passage in fear-motivated behavior. The IBO lesions led to increased open-field activity, but no impairments in active avoidance learning, nor changes in basal or experimental levels of plasma corticosterone. The RF lesions, on the other hand, led to an increase in experimental plasma corticosterone levels. In the one-way avoidance task the RF lesions, in contrast to the IBO lesions, led to significant impairments in the acquisition of the avoidance response. Although the long-term axon-sparing effect of IBO is questioned since cavities were detected in the affected areas 8 weeks after the injections, the differences in avoidance learning and in corticosterone levels between the RF and the IBO lesions indicate that the axons were functionally active at the time of testing (14-26 days postoperatively). The increase in open-field activity is attributed to the destruction of amygdala neurons and neurons in the overlying cortex, while an avoidance deficit seem to depend on the destruction of axons. On the basis of the behavioral results and the corticosterone data in these experiments, it is suggested that the behavioral changes are not attributable to a general reduction in the arousal of fear. However, since the IBO lesions did not affect the most medial parts of the amygdala complex including the central amygdala nucleus, the role of this nucleus in fear arousal has to be investigated further.