Heart rate and respiration in reptiles: contrasts between a sit-and-wait predator and an intensive forager

The current study investigated respiration and heart rate in two species of reptiles with distinct behavioral strategies: (1) the Sudan plated lizard (Gerrhosaurus major), a sit-and-wait predator; and (2) the Savanna monitor (Varanus exanthematicus), an intensive forager. It was hypothesized that (a) the plated lizard would not express respiratory sinus arrhythmia, and (b) the monitor, a reptile with behavioral and physiological characteristics similar to mammals, might express respiratory sinus arrhythmia, a pattern previously observed only in mammals. The data demonstrated that although there were strong vagal influences on the heart, respiratory activity was not manifested in the heart rate pattern of the plated lizards. In contrast, the monitor exhibited a reliable ventilatory influence on the heart rate pattern, although the pattern differed from the respiratory sinus arrhythmia observed in mammals. Consistent with the Polyvagal Theory (), the vagal control of the reptilian heart in both species appears to be mediated through the phylogenetically older unmyelinated system, a system that evolved to support metabolic conservation and not social behavior.     

A Meta-Analysis of Structural and Functional Brain Imaging in Dementia of the Alzheimer's Type: A Neuroimaging Profile

We conducted a quantitative review of the imaging literature using meta-analytic methodology to characterize further the magnitude of hippocampal deficit in probable Alzheimer's disease (AD) and to determine whether other neuroanatomic structures in AD can better discriminate the disease from normal aging. Additionally, we parceled the discriminability of neuroanatomic structures by duration of disease to determine those structures most sensitive to AD in its early and late stages. One hundred twenty-one studies published between 1984 and 2000 met criteria for inclusion in the present analysis. In total, structural (i.e., CT and MRI) and functional (i.e., SPECT and PET) neuroimaging results from 3511 patients with AD, and 1632 normal healthy controls were recorded across meta-analyses. Our results include neuroimaging profiles for both early onset and longer duration patients with AD. In sum, these profiles yield a signature of diagnostic markers in both cortical and subcortical neuroanatomic areas. This signature is consistent with the clinical phenomenology of Alzheimer's dementia and should aid in the positive identification of AD.     

Internet use by the socially fearful: addiction or therapy?

The Internet has often been argued to have adverse psychological consequences, such as depression or anxiety symptoms, among "over-users." The present study offers an alternative understanding, suggesting the Internet may be used as a forum for expanding social networks and consequently enhancing the chance of meaningful relationships, self-confidence, social abilities, and social support. An online sample of 188 people was recruited over the Internet, while paper and pencil tests were administered to an offline sample group of 27 undergraduate university students, who were regular Internet users. Subjects completed the Zung Depression Scale (ZDS), Depression, Anxiety and Stress Scales (DASS), Eysenck Personality Questionnaire?Revised Short Scale (EPQ-R Short), Fear of Negative Evaluation (FNE) scale, Internet Use Questionnaire (IUQ), and an Internet Effects Questionnaire (IEQ). Results suggested that there was no relationship between time spent online and depression, anxiety, or social fearfulness. Those who primarily used the Internet for online chat believed that the Internet is psychologically beneficial to them, but also believed that frequent Internet users are lonely and that the Internet can be addictive. It is argued that "chat" users who are socially fearful may be using the Internet as a form of low-risk social approach and an opportunity to rehearse social behavior and communication skills, which, may help them improve interaction with offline, face-to-face, social environments.     

Memory on the beach: an Australian memory (and hypnosis) laboratory

The memory (and hypnosis) lab at the University of New South Wales investigates a broad range of memory topics. We try to find innovative methods from cognitive and clinical psychology to address theoretical and empirical questions about memory. We aso use hypnosis as one major methodological tool in our investigations of memory (as well as other cognitive processes). In this paper, we review the projects currently underway in our memory (and hypnosis) lab.     

Shame coping styles and psychopathic personality traits

The convergent validity of the primary and secondary psychopathy scales of the Levenson, Kiehl, and Fitzpatrick (1995) Self-Report Psychopathy Scale (SRPS) were investigated by contrasting correlations between the two SRPS scales and self-report adaptive and maladaptive shame coping scales. The results, from a sample of 305 undergraduates, supported the convergent validity of the SRPS primary (selfish, uncaring, manipulative interpersonal style) and secondary (impulsivity and self-defeating behavior) scales; both possessed small but significant negative relationships with adaptive shame coping and small but significant positive relationships with externalizing shame coping. An opposing pattern of convergent validity was evidenced by partial correlations (controlling for SPRS scale covariance) that indicated the SRPS primary scale had a negative relationship and the secondary scale had a positive relationship to internalizing shame coping.     

Measuring men's response to an imagined negative body image

To investigate response to an imagined negative body image, a sample of 29 men from an undergraduate university were given the Body Image Affect Scale of Campbell and Chow. Analysis showed more men, if they are experiencing a poor appearance, would try to cover up physical flaws and avoid approaching an individual in whom they were interested.     

Understanding the social costs of narcissism: the case of the tragedy of the commons

Two studies examined narcissism and behavior in a commons dilemma. Study 1 used a four-person, laboratory-based task and Study 2 used a dyadic task. Participants were told that they represented one of four (Study 1) or two (Study 2) forestry companies and then were asked to harvest timber from a renewable forest. Narcissism was found to be positively related to acquisitive goals and harvesting more timber in the initial round. The more narcissists harvesting in the competitive group of four (Study 1) or dyad (Study 2), the less timber was harvested overall and the more rapidly the forest was depleted. Within competitive groups and dyads, however, narcissists harvested more than the nonnarcissists competing with them. In all, narcissism provided a benefit to the self, but at a long-term cost to other individuals and to the commons.     

Perceptual asymmetries are preserved in memory for highly familiar faces of self and friend

We investigated the effect of familiarity on people's perception of facial likeness by asking participants to choose which of two mirror-symmetric chimeric images (made from the left or right half of a photograph of a face) looked more like an original image. In separate trials the participants made this judgment for their own face and for the face of a close friend; half of them matched to a true image of the original and half matched to a mirror image of the original. In the case of matching to a friend's face presented in the familiar orientation, over 80% of participants chose the left-left composite to be a better likeness to the original, whereas only 62% showed the same left-side bias when matching to a mirror image. The difference is significant, and the result contrasts markedly with a second experiment where participants who were unfamiliar with the faces showed comparable left-side biases when matching to true or mirror reversed images. The result suggests that perceptual asymmetries are retained in our long-term memory for highly familiar faces. While matching to images of self also showed an effect of familiarity, the data in this condition show less evidence of perceptual asymmetry and are discussed in relation to recent research on the representation of one's own face.     

Calculation,culture, and the repeated operand effect

A basic phenomenon of cognitive arithmetic is that problems composed of a repeated operand, so-called "ties" (e.g. 6+6, 7 x 7), typically are solved more quickly and accurately than comparable non-tie problems (e.g. 6+5, 7 x 8). In Experiment 1, we present evidence that the tie effect is due to more efficient memory for ties than for non-ties, which participants reported solving more often using calculation strategies. The memory/strategy hypothesis accounts for differences in the tie effect as a function of culture (Asian Chinese vs. non-Asian Canadian university students), operation (addition, multiplication, subtraction, and division), and problem size (numerically small vs. large problems). Nonetheless, Blankenberger (Cognition 82 (2001) B15) eliminated the tie response time (RT) advantage by presenting problems in mixed formats (e.g. 4 x four), which suggests that the tie effect with homogenous formats (4 x 4 or four x four) is due to encoding. In Experiment 2, using simple multiplication problems, we replicated elimination of the tie effect with mixed formats, but also demonstrated an interference effect for mixed-format ties that slowed RTs and increased errors relative to non-tie problems. Additionally, practicing non-tie problems in both orders (e.g. 3 x 4 and 4 x 3) each time ties were tested once (cf. Cognition 82 (2001) B15) reduced the tie effect. The format-mismatch effect on ties, combined with a reduced tie advantage because of extra practice of non-ties, eliminated the tie effect. Rather than an encoding advantage, the results indicate that memory access for ties was better than for non-ties.