Observing a fictitious stressful event: haematological changes,including circulating leukocyte activation

The aim of this study was to assess the effect of watching a psychological stressful event on the activation of leukocytes in healthy human volunteers. Blood samples were obtained from 32 healthy male and female subjects aged between 20 and 26 years before, during and after either watching an 83-minute horror film that none of the subjects had previously seen (The Texas Chainsaw Massacre, 1974) or by sitting quietly in a room (control group). Total differential cell counts, leukocyte activation as measured by the nitroblue tetrazolium (NBT) test, heart rate and blood pressure (BP) measurements were taken at defined time points. There were significant increases in peripheral circulating leukocytes, the number of activated circulating leukocytes, haemoglobin (Hb) concentration and haematocrit (Hct) in response to the stressor. These were accompanied by significant increases in heart rate, systolic and diastolic BP (P<0.05 from baseline). This is the first reported study on the effects of observing a psychologically stressful, albeit fictitious event on circulating leukocyte numbers and the state of leukocyte activation as determined by the nitrotetrazolium test.     

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.     

Measuring the speed of the conscious components of recognition memory: remembering is faster than knowing

Three experiments investigated response times (RTs) for remember and know responses in recognition memory. RTs to remember responses were faster than RTs to know responses, regardless of whether the remember-know decision was preceded by an old/new decision (two-step procedure) or was made without a preceding old/new decision (one-step procedure). The finding of faster RTs for R responses was also found when remember-know decisions were made retrospectively. These findings are inconsistent with dual-process models of recognition memory, which predict that recollection is slower and more effortful than familiarity. Word frequency did not influence RTs, but remember responses were faster for words than for nonwords. We argue that the difference in RTs to remember and know responses reflects the time taken to make old/new decisions on the basis of the type of information activated at test.     

Cognitions and depressive symptoms among ethnic minority adolescents

Cognitive models have guided effective intervention strategies in the treatment of depression. However, little is known about the cognitive model's relevance in different cultural ethnic groups in the United States. This study examines the cross-sectional and longitudinal associations among cognitive variables and depressive symptoms among African American, Caucasian, and Hispanic adolescents in the United States. Community adolescents (N = 450) ages 14-18 years (African American n = 79; Caucasian n = 273; Hispanic n = 98) provided information regarding their depressive symptoms and cognitions at two surveys, 6 months apart. Self-efficacy, cognitive errors, and hopelessness were associated with concurrent depressive symptoms at baseline. In addition, cognitive errors at baseline, controlling for baseline depressive symptoms and the occurrence of stressful events, predicted depressive symptoms at follow-up. Ethnic differences disappeared when parent education level was controlled. Our findings demonstrate support for the cognitive model of depression across ethnic groups. The importance of controlling for social class when examining ethnic differences in psychological variables is highlighted by our findings.     

How is the serial order of a verbal sequence coded? Some comparisons between models

Current models of verbal short-term memory (STM) propose various mechanisms for serial order. These include a gradient of activation over items, associations between items, and associations between items and their positions relative to the start or end of a sequence. We compared models using a variant of Hebb's procedure in which immediate serial recall of a sequence improves if the sequence is presented more than once. However, instead of repeating a complete sequence, we repeated different aspects of serial order information common to training lists and a subsequent test list. In Experiment 1, training lists repeated all the item-item pairings in the test list, with or without the position-item pairings in the test list. Substantial learning relative to a control condition was observed only when training lists repeated item-item pairs with position-item pairs, and position was defined relative to the start rather than end of a sequence. Experiment 2 attempted to analyse the basis of this learning effect further by repeating fragments of the test list during training, where fragments consisted of either isolated position-item pairings or clusters of both position-item and item-item pairings. Repetition of sequence fragments led to only weak learning effects. However, where learning was observed it was for specific position-item pairings. We conclude that positional cues play an important role in the coding of serial order in memory but that the information required to learn a sequence goes beyond position-item associations. We suggest that whereas STM for a novel sequence is based on positional cues, learning a sequence involves the development of some additional representation of the sequence as a whole.     

Transposition asymmetry in immediate serial recall

When participants confuse the position of items in immediate serial recall, they tend to recall transposed items too early rather than too late. This asymmetry of transposition errors was observed in four experiments. It increased as a function of list length, but was independent of report order, output position, cueing condition, and recall mode. The transposition asymmetry is consistent with error patterns in free recall and in regular speech production where transpositions are usually forward-looking. The asymmetry of transposition errors is discussed in terms of models of serial memory.     

Ability of substance abusers to escape detection on the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A) in a juvenile correctional facility

The ability of respondents to underreport successfully on substance abuse and validity scales of the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A; Butcher et al., 1992) was evaluated. Incarcerated teens (67 substance abusing, 59 non-substance abusing) completed the MMPI-A twice: once under standard instructions (SI) and once under instructions to fake good (FG). Under SI, substance scales correctly classified about 60% to 85% of adolescents. Under FG, substance- and non-substance-abusing juveniles produced lower scores on substance scales. However, the Lie Scale (L) was able to detect more than 75% of deceptive profiles and about 77% of honest profiles. When scale L and the best substance scale were used in combination, only about 18% of faking substance abusers were not identified as either substance abusers or as underreporting. For feigning substance abusers, only about 10% of substance abusers were detected, with about 72% being categorized as faking and needing further assessment.     

A mood-as-input account of perseverative checking: the relationship between stop rules, mood and confidence in having checked successfully

The present paper reports the results of two experiments designed to test predictions from the mood-as-input account of perseverative checking. Using an analogue checking task, both experiments showed that perseveration, as indicted by a range of measures relevant to compulsive checking, was affected by the configuration of the stop rule for the task and mood at the outset of checking. Perseveration was most significant in the condition that most closely resembled the characteristics of obsessive-compulsive checkers (negative mood combined with a stop rule that specifies that the task should be done as thoroughly as possible--namely, an 'as many as can' stop rule). The studies also indicated that confidence at having completed the checking task successfully was (1) significantly related to the use of 'as many as can' stop rules at the outset of checking, (2) mood ratings at the end of checking, and (3) checking perseveration generally. These findings provide support for a mood-as-input explanation of perseverative psychopathologies such as compulsive checking, and begin to cast some light on how anxiety-reduction and 'confidence' models of compulsive checking, might be explained within broader mechanisms of perseveration.     

Assessing psychopathic personality traits with the MMPI-2

In this study, we examined the utility of the MMPI-2 (Butcher et al., 2001) in assessing psychopathic personality traits. We explored whether MMPI-2 scales that measure affective and interpersonal traits add to the instrument's social deviance measures in assessing global psychopathy and its two facets. Our study of 281 male and female college students indicates that the MMPI-2 Social Deviance scales (e.g., Clinical Scales 4 and 9, ASP) predict substantial variance in the social deviance factor and affiliated subscales of the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996), whereas MMPI-2 measures of affective and interpersonal functioning predict substantial variance in the affective-interpersonal PPI factor. In addition, the results of two regression models indicate that the Restructured Clinical scales provide the most parsimonious assessment of psychopathic personality traits.