Place learning in scopolamine-treated rats: the roles of distal cues and catecholaminergic mediation

Experiments 1 and 2 tested the hypothesis that cholinergic receptor antagonists impair place learning in a water maze by interfering with the processing of distal, visual cues. Extramaze cues were offered to rats in the form of geometrical patterns arranged on the inner circumference of a curtain surrounding the water maze. In Experiment 1 the animals were offered both the distal cues and proximal cues in the form of pingpong balls in fixed positions on the surface of the water while only distal cues were present in Experiment 2. Animals were injected with either scopolamine (0.5 mg/kg body wt) or saline 20 min prior to the daily place learning sessions. Upon reaching criterion level performance the animals were tested on "rotation" sessions on which the distal cues were displaced. The outcome of such "rotations" demonstrated that-regardless of the presence or absence of proximal cues-scopolamine-treated rats relied at least as much as normal animals on the distal cues. The acquisition phase of both Experiments 1 and 2 demonstrated an almost complete lack of scopolamine-associated impairment in acquisition and performance of the place learning task. In Experiment 3 (when scopolamine was no longer administered) the subjects of Experiment 2 were exposed to a series of pharmacological "challenges" of their place learning performance and eventually to surgical ablation of the anteromedial prefrontal cortex. The outcome of the pharmacological challenges and the postoperative test of task performance demonstrated that the place learning performance of animals which had acquired the task under scopolamine was mediated by a neural substrate dissimilar to the substrate of task performance in normal animals. Rats acquiring the task while deprived of the cholinergic system demonstrated above-normal contributions to task mediation from catecholaminergic-probably dopaminergic-mechanisms and tentative results pointed to a "shift" toward prefrontal task mediation.     

Lateralization of squamous cell carcinomas in the head-neck region

Earlier studies have shown the lateralization of several immune disorders, including herpes zoster infection and breast cancer. We investigated whether there is lateralization of squamous cell carcinomas in the head-neck region and a relation of handedness with this cancer. Analysis showed right-sided lateralization of head-heck cancers in right-handed patients and vice versa in left-handed ones and a higher rate of left-handedness in patients with squamous cell cancer. Associations among left-handedness, squamous cell carcinoma, and its lateralization may result from a genetic togetherness.     

Characteristics of auditory agnosia in a child with severe traumatic brain injury: a case report

We present a case that is unusual in many respects from other documented incidences of auditory agnosia, including the mechanism of injury, age of the individual, and location of neurological insult. The clinical presentation is one of disturbance in the perception of spoken language, music, pitch, emotional prosody, and temporal auditory processing in the absence of significant deficits in the comprehension of written language, expressive language production, or peripheral auditory function. Furthermore, the patient demonstrates relatively preserved function in other aspects of audition such as sound localization, voice recognition, and perception of animal noises and environmental sounds. This case study demonstrates that auditory agnosia is possible following traumatic brain injury in a child, and illustrates the necessity of assessment with a wide variety of auditory stimuli to fully characterize auditory agnosia in a single individual.     

Both sides get the point: Hemispheric sensitivities to sentential constraint

Behavioral studies have consistently reported striking differences in the impact of sentence-level information on the processing of words presented in the right (RVF) versus the left (LVF) visual field, with context effects apparent only for RVF items. The consistent lack of such effects in the LVF has been taken to mean that right hemisphere language comprehension is largely insensitive to message-level meaning. We used the functional specificity afforded by event-related potential measures to assess this claim. Target words completing strongly and weakly constraining sentence contexts, in which constraint arose at the sentence level rather than from lexical associations, were presented laterally in the LVF or RVF. Increased constraint significantly reduced N400 amplitudes with presentation in both VFs, with no differences in the timing or amplitude of these effects. These results are inconsistent with the view that the VF asymmetries found in behavioral measures reflect differential hemispheric capacities at the level of semantic analysis and integration, although VF-based differences on earlier components (P2) suggest asymmetries in the impact of sentential context on perceptual aspects of word processing in the two hemispheres.     

Bottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members

Bottlenose dolphins are unusual among non-human mammals in their ability to learn new sounds. This study investigates the importance of vocal learning in the development of dolphin signature whistles and the influence of social interactions on that process. We used focal animal behavioral follows to observe six calves in Sarasota Bay, Fla., recording their social associations during their first summer, and their signature whistles during their second. The signature whistles of five calves were determined. Using dynamic time warping (DTW) of frequency contours, the calves signature whistles were compared to the signature whistles of several sets of dolphins: their own associates, the other calves associates, Tampa Bay dolphins, and captive dolphins. Whistles were considered similar if their DTW similarity score was greater than those of 95% of the whistle comparisons. Association was defined primarily in terms of time within 50 m of the mother/calf pair. On average, there were six dolphins with signature whistles similar to the signature whistles of each of the calves. These were significantly more likely to be Sarasota Bay resident dolphins than non-Sarasota dolphins, and (though not significantly) more likely to be dolphins that were within 50 m of the mother and calf less than 5% of the time. These results suggest that calves may model their signature whistles on the signature whistles of members of their community, possibly community members with whom they associate only rarely.     

Children's understanding of television advertising: a revisit in the Chinese context

The authors conducted a survey of 1,758 elementary school children (6-14 years old) from December 2001, to March 2002, in 3 Chinese cities with different levels of television advertising. The authors used D. R. John's (1999) model of consumer socialization as the theoretical framework for their study. More than half of the children whom the authors interviewed were able to understand that television stations broadcast commercials to earn money. Their understanding of the purposes of television commercials and the persuasive intention of television commercials developed with age. The authors examined the influence of gender, level of advertising, and level of television viewing on children's understanding of television advertising by using 3-way factorial models.     

The relationship between interpersonal perception and post-traumatic stress disorder-related functional impairment: a social relations model analysis

This study used Kenny's social relations model to examine the relationship between Post-Traumatic Stress Disorder-related impairment and interpersonal perceptions. Participants were 124 students who had previously completed the Post-traumatic Stress Diagnostic Scale as part of a larger study. After engaging in brief dyadic conversations with 3 other students, participants recorded perceptions of personality traits for themselves, their interaction partners and how they believed their partners saw them (metaperceptions). Results indicated that those with more severe post-traumatic stress disorder-related impairment saw themselves negatively and believed their interaction partners also viewed them negatively. However, these individuals were not seen differently by others, except that they were rated as less dependable. Our findings suggest that post-traumatic stress disorder is associated with negative beliefs about the self that may influence self-esteem and interpersonal relationships.     

Flirting and energetic arousal

76 college students were administered a self-reported energy scale and a flirtation inventory. Analysis indicated a significant relationship such that low scores on energy level were associated with low flirtation related activities, as well as low self-ratings on attractiveness and other variables.