Do animals dream?

The understanding of biological functions of sleep has improved recently, including an understanding of the deep evolutionary roots of sleep among animals. However, dreaming as an element of sleep may be particularly difficult to address in non-human animals because in humans dreaming involves a non-wakeful form of awareness typically identified through verbal report. Here, we argue that parallels that exist between the phenomenology, physiology, and sleep behaviors during human dreaming provide an avenue to investigate dreaming in non-human animals. We review three alternative measurements of human dreaming - neural correlates of dreaming, 'replay' of newly-acquired memories, and dream-enacting behaviors - and consider how these may be applied to non-human animal models. We suggest that while animals close in brain structure to humans (such as mammals and birds) may be optimal models for the first two of these measurements, cephalopods, especially octopuses, may be particularly good candidates for the third.

A case of lymphomatoid granulomatosis masquerading as a lung abscess

Lymphomatoid granulomatosis (LG) is a rare T cell rich, B cell non-Hodgkin's lymphoma which is difficult to diagnose. We present a patient with LG who demonstrated many of the difficulties in diagnosis and highlighted the importance of reviewing the diagnosis if treatment does not have the anticipated effect.

Total energy expenditure in stable patients with cystic fibrosis

BACKGROUND AND AIMS

Undernutrition is a common problem in patients with cystic fibrosis and is associated with a poor prognosis. The two aims of this study were to assess and compare the two main field techniques in the measurement of total energy expenditure and, secondly, to assess total energy expenditure in stable patients and compare with healthy controls.

METHODS

Resting energy expenditure was measured using indirect calorimetry and total energy expenditure was measured using 24-h heart rate (HR) methodology and doubly isotopically labelled water.

RESULTS

Seventeen patients, mean age 23 years and FEV(1)52% predicted and thirteen controls were recruited. Resting energy expenditure was higher in patients 0.24 (0.03) MJ/kg Fat-Free Mass (FFM) compared to controls 0.22 (0.02) MJ/kg FFM, P=0.02. Twenty-four hour heart rate underestimated total energy expenditure, 9.49 (1.85) MJ/day in patients compared to 11.69 (2.79) MJ/day using doubly labelled water. There was no difference in total energy expenditure in patients and controls using both methods, 11.69 (2.79) MJ/day compared to 11.38 (2.71) MJ/day using doubly isotopically labelled water.

CONCLUSIONS

In clinically stable young adult patients with moderately severe respiratory disease total energy expenditure is comparable to that an a control population despite in increase in resting energy expenditure and both 24-h HR and doubly isotopically labelled water are suitable for use in patients with cystic fibrosis.

Clinical outcome after acquisition of Burkholderia cepacia in patients with cystic fibrosis

BACKGROUND

Respiratory disease is the major cause of morbidity and mortality in cystic fibrosis (CF). The significance of Burkholderia cepacia (B. cepacia) in the pathogenesis of lung disease in CF is debated, but its exact role remains unclear.

AIM

To assess the impact of respiratory tract colonisation with B. cepacia in patients with CF by measuring changes in pulmonary function and body mass index (BMI).

METHODS

Three groups of patients were defined based on sputum culture isolates: Group 1 were B. cepacia and Pseudomonas aeruginosa (P. aeruginosa) positive patients; Group 2 were P. aeruginosa positive; and Group 3 were colonised with neither organism. Forced expiratory volume (FEV) and BMI were measured annually from 1987 to 1995 and the year of acquisition of P. aeruginosa or B. cepacia was recorded.

RESULTS

The mean annual decrease in FEV1 was significantly different in all three groups: Group 1, -5.4 (5.1)%; Group 2, -3.9 (6.5)%; and Group 3, -1.6 (1.0)%, (p<0.05). The mean percentage decrease in FEV1 of a sub-group of Group 1 patients where the B. cepacia acquisition date was known was 6.1% per year versus 1.55% in Group 2 patients (p<0.05).

CONCLUSIONS

Acquisition of B. cepacia may be a cause of, rather than a marker for, a decrease in pulmonary function.

Attention-referenced visual representations: evidence from impaired visual localization

Spatial representations in the visual system were probed in 4 experiments involving A. H., a woman with a developmental deficit in localizing visual stimuli. Previous research (M. McCloskey et al., 1995) has shown that A. H.'s localization errors take the form of reflections across a central vertical or horizontal axis (e.g., a stimulus 30 degrees to her left localized to a position 30 degrees to her right). The present experiments demonstrate that A. H.'s errors vary systematically as a function of where her attention is focused, independent of how her eyes, head, or body are oriented, or what potential reference points are present in the visual field. These results suggest that the normal visual system constructs attention-referenced spatial representations, in which the focus of attention defines the origin of a spatial coordinate system. A more general implication is that some of the brain's spatial representations take the form of coordinate systems.

Clinical features associated with a delayed diagnosis of cystic fibrosis

BACKGROUND

The majority of patients with cystic fibrosis (CF) are diagnosed in the first decade of life. In a small number of patients, the diagnosis is not made until later.

OBJECTIVE

In this study, the clinical and genetic features of patients diagnosed after the age of 10 were examined.

METHODS

All living patients in Northern Ireland diagnosed prior to 1983, when neonatal screening was introduced, were studied. A total of 103 patients were identified of whom 18 were diagnosed after the age of 10. The relationships between late diagnosis and clinical presentation, sputum microbiology, pancreatic sufficiency, nutritional status, genotype and distance from the regional CF centres was determined by multiple regression analysis.

RESULTS

All 18 late-diagnosed patients had a sweat (chloride >70 mmol/l). Late diagnosis was significantly related to carriage of the R117H mutation (r(2) = 0.45) and pancreatic sufficiency (r(2) = 0.37). There was a weak relationship with pulmonary function (r(2) = 0.09).

CONCLUSIONS

In Northern Ireland, late diagnosis in mainly associated with pancreatic function and carriage of the R117H mutation.

Attention-referenced visual representations: evidence from impaired visual localization

Spatial representations in the visual system were probed in 4 experiments involving A. H., a woman with a developmental deficit in localizing visual stimuli. Previous research (M. McCloskey et al., 1995) has shown that A. H.'s localization errors take the form of reflections across a central vertical or horizontal axis (e.g., a stimulus 30 degrees to her left localized to a position 30 degrees to her right). The present experiments demonstrate that A. H.'s errors vary systematically as a function of where her attention is focused, independent of how her eyes, head, or body are oriented, or what potential reference points are present in the visual field. These results suggest that the normal visual system constructs attention-referenced spatial representations, in which the focus of attention defines the origin of a spatial coordinate system. A more general implication is that some of the brain's spatial representations take the form of coordinate systems.

The industry manipulation attitudes of smokers and nonsmokers

A cross-sectional random sample was obtained of Florida youth between the ages of 12-17. Data were collected through a telephone survey after obtaining parent and child consent. Industry manipulation attitudes of three groups (self-identified nonsmokers who did not use cigarettes in the past 30 days, self-identified nonsmokers who used cigarettes in the past 30 days, and self-identified smokers who used cigarettes in the past 30 days) were compared. Constraints resulting from the method of data collection resulted in a conservative estimate of the strength of the association between industry manipulation attitudes and smoking behavior.

Retransplantation in a patient with cystic fibrosis

A patient with cystic fibrosis is described who requested a third lung transplant. The medical and ethical issues involved are discussed.

Progressive massive fibrosis in the absence of lung nodulation

Progressive massive fibrosis is a well-recognized complication of long-term industrial dust exposure. Typically, it occurs in a setting of background parenchymal nodulation. We wish to report a case occurring in the absence of lung nodules.

Near-field confocal optical spectroscopy (NCOS): subdiffraction optical resolution for biological systems

Optical resolution is limited by diffraction. However, in near-field microscopes sample illumination is provided through a subwavelength aperture to increase optical resolution. In this study we have evaluated the usefulness of this technique for living biological systems and report two significant improvements in this form of microscopy to enhance optical resolution for biological studies. We report a unique feedback method, photon-density feedback, which is used to monitor the registration of a near-field illumination probe with living cell membranes. In this method, the fluorescence intensity of a uniformly distributed fluorochrome is monitored while the sample is moved in the z-axis towards the probe. Upon contact between the cell membrane and the near-field probe a maximum intensity is detected. A problem with near-field microscopy is that enhanced optical resolution is only achieved within the near-field of the illuminating aperture. Thick biological specimens also fluoresce in the far-field reducing optical resolution. To reduce this problem we incorporated a confocal pinhole together with the near-field probe to enhance the resolution of this form of near-field microscopy. Finally, we demonstrate that near-field confocal optical spectroscopy does not impair physiological properties of neurons, astrocytes or mast cells, indicating that this high-resolution optical methodology will permit a new approach to the study of molecular distribution and action within living specimens.

CT of pancreatic gas gangrene

A case of gas gangrene complicating acute pancreatitis is presented. The presence of gas within the pancreatic bed is very suggestive of infection with gas forming organisms in the right clinical setting.

Representing and using numerical information

Issues of mental representation are central to cognitive psychology and indeed to psychology in general. This article synthesizes recent theoretical and empirical research concerning cognitive representations in one specific domain, that of numbers. First, several forms of cognitive numerical representation are defined, and the roles the various forms may play in numerical processing are considered. Then, two current representational issues that have generated some controversy are examined: In what form are arithmetic table facts (e.g., 4 x 7 = 28) stored in memory, and what forms of representation are involved in converting numerals from one form to another (as in reading 604 aloud as "six hundred four")? In the course of the discussion the major current theories of numerical cognition are described, with emphasis on how they differ in their assumptions about numerical representations and how these differences are reflected in the positions taken on various specific issues.

Representing and using numerical information

Issues of mental representation are central to cognitive psychology and indeed to psychology in general. This article synthesizes recent theoretical and empirical research concerning cognitive representations in one specific domain, that of numbers. First, several forms of cognitive numerical representation are defined, and the roles the various forms may play in numerical processing are considered. Then, two current representational issues that have generated some controversy are examined: In what form are arithmetic table facts (e.g., 4 x 7 = 28) stored in memory, and what forms of representation are involved in converting numerals from one form to another (as in reading 604 aloud as "six hundred four")? In the course of the discussion the major current theories of numerical cognition are described, with emphasis on how they differ in their assumptions about numerical representations and how these differences are reflected in the positions taken on various specific issues.

The organization of arithmetic facts in memory: evidence from a brain-damaged patient

We report a single case study of a brain-damaged patient with impaired arithmetic performance. Three principal findings are presented: First, in a task involving production of answers to simple arithmetic problems, the patient's performance was far better for subtraction than for addition or multiplication. Second, in all arithmetic operations performance was generally much better for problems potentially solvable by rule (e.g., 5 + 0) than for problems requiring retrieval of specific facts (e.g., 5 + 3). Third, the dissociation between subtraction and the other arithmetic operations obtained in the production task was not observed in a verification task. The implications of these findings for claims concerning the organization of stored arithmetic facts are discussed.

Cognitive mechanisms in numerical processing: evidence from acquired dyscalculia

This article discusses cognitive neuropsychological research on acquired dyscalculia (i.e., impaired numerical processing resulting from brain damage), surveying issues of current interest, and illustrating the ways in which analyses of acquired deficits can contribute to an understanding of normal processing. I first review the logic whereby inferences concerning normal cognition are drawn from patterns of impaired performance. I then consider research exploring the general functional architecture of the cognitive numerical processing mechanisms, and finally turn to studies aimed at probing the internal structure and functioning of individual processing components.

Theory-based assessment of acquired dyscalculia

This article describes a theory-based approach to assessment of acquired dyscalculia. A model of the normal cognitive number-processing/calculation system is presented, and methods are discussed for characterizing number-processing/calculation deficits in terms of functional damage to the mechanisms specified in the model.

Facts, rules, and procedures in normal calculation: evidence from multiple single-patient studies of impaired arithmetic fact retrieval

This article presents results from multiple single-case studies of brain-damaged patients with impairments in retrieval of arithmetic facts (i.e., "table" facts such as 8 x 7 = 56). The results provide a basis for exploring the types of knowledge implicated in simple arithmetic performance, the internal representations for the various knowledge types, the processes operating upon these representations, and the ways in which the representations or processes may be disrupted by brain damage.

Cognitive representations and processes in arithmetic: inferences from the performance of brain-damaged subjects

In this article, we present data from two brain-damaged patients with calculation impairments in support of claims about the cognitive mechanisms underlying simple arithmetic performance. We first present a model of the functional architecture of the cognitive calculation system based on previous research. We then elaborate this architecture through detailed examination of the patterns of spared and impaired performance of the two patients. From the patients' performance we make the following theoretical claims: that some arithmetic facts are stored in the form of individual fact representations (e.g., 9 x 4 = 36), whereas other facts are stored in the form of a general rule (e.g., 0 x N = 0); that arithmetic fact retrieval is mediated by abstract internal representations that are independent of the form in which problems are presented or responses are given; that arithmetic facts and calculation procedures are functionally independent; and that calculation algorithms may include special-case procedures that function to increase the speed or efficiency of problem solving. We conclude with a discussion of several more general issues relevant to the reported research.

Models of arithmetic fact retrieval: an evaluation in light of findings from normal and brain-damaged subjects

Retrieval of basic arithmetic facts is a central aspect of almost any arithmetic performance. Furthermore, the arithmetic facts provide an opportunity to study memory processes in the context of a naturally occurring but circumscribed set of facts. This article examines current models of arithmetic fact retrieval in light of previously reported data from normal subjects, as well as the results from brain-damaged patients reported by Sokol, McCloskey, Cohen, and Aliminosa (1991) in the preceding article. The discussion serves to delineate the strengths and limitations of the models and, more generally, to identify important theoretical and empirical issues in the study of arithmetic fact retrieval.

Effect of gonadotropin-releasing hormone on fertility in repeat-breeder California dairy cows

To assess the potential benefit to fertility from gonadotropin-releasing hormone (GnRH) administration to third service cows managed in typical California dairy systems, 963 cows were enlisted from 14 dairies served by 6 veterinary practices. The cows were randomly assigned to receive either GnRH (100 mug) or placebo at the time of the third artificial insemination. Fertility data were entered onto a proprietary microcomputer program common to all six practices, and collated independently by a third party. For the duration of the trial (1 yr), GnRH and placebo-treated cows had 43.2 and 39.3% conception rates, respectively (P=0.35). When treatments administered in summer months (July, August, September) were excluded, conception rates were 48.1 and 41.0%, respectively (P<0.1). The conception rates of cows treated with GnRH in August tended to be lower than those of placebo-treated cows (95% logarithmic confidence intervals of odds ratio = -1.139, 0.377). Between-herd variation in benefit from GnRH was evident, with two dairies showing no benefit, one dairy showing a negative effect, and four showing a range of effects from lightly beneficial to significantly beneficial. First-lactation cows did not benefit at any time from GnRH treatment. The data suggest that GnRH administered to third-service dairy cows under California conditions may result in increased conception rates in non-summer months, but that other unidentified variables may have important influence on the outcome of such treatment.

In defense of a modular architecture for the number-processing system: reply to Campbell and Clark

In several recent articles we have developed a model of the cognitive number-processing and calculation systems. Campbell and Clark (1988), commenting on one of these articles (McCloskey, Sokol, & Goodman, 1986), called into question our model's assumption of a modular functional architecture and a single form of internal numerical representation. Campbell and Clark proposed as an alternative a nonmodular encoding-complex view. In this reply we discuss the results offered by Campbell and Clark as evidence against our model, arguing that several of these results are in fact consistent with the model and that the remaining results, while raising significant issues, by no means justify abandonment of the modular framework and the constraints it imposes. We also point out that whereas our model provides specific, well-motivated interpretations for a substantial body of empirical findings, the encoding-complex view is so underspecified and unconstrained as to be vacuous.

In defense of a modular architecture for the number-processing system: Reply to Campbell and Clark

In several recent articles we have developed a model of the cognitive number-processing and calculation systems. Campbell and Clark (1988), commenting on one of these articles (McCloskey, Sokol, & Goodman, 1986), called into question our model's assumption of a modular functional architecture and a single form of internal numerical representation. Campbell and Clark proposed as an alternative a nonmodular encoding-complex view. In this reply we discuss the results offered by Campbell and Clark as evidence against our model, arguing that several of these results are in fact consistent with the model and that the remaining results, while raising significant issues, by no means justify abandonment of the modular framework and the constraints it imposes. We also point out that whereas our model provides specific, well-motivated interpretations for a substantial body of empirical findings, the encoding-complex view is so underspecified and unconstrained as to be vacuous.

Calcium and the production of interferon by human peripheral blood mononuclear cells

We have studied the ability of human peripheral blood mononuclear cells (PBMC) to produce interferon-alpha (IFN-alpha) and IFN-gamma in the presence of pharmacologic agents known to influence calcium transport or calcium-dependent processes. We have found that the production of human (Hu) IFN-gamma is affected significantly by alterations in calcium flux; however, this influence is dependent upon the nature of the compound used to induce IFN. Inhibitors of protein kinase C decreased yields of IFN-gamma but inhibition of calmodulin did not. The presence of vitamin D3 reduced IFN-gamma titers when PHA and IL-2 were used to induce IFN, but not when ionomycin was used as the inducer. The production of IFN-gamma by PBMC was reduced by diminished concentrations in extracellular calcium but not extracellular magnesium. In contrast, neither the presence of any of the pharmacological agents tested above nor the reduction of the calcium concentration influenced the production of HuIFN-alpha by PBMC.

Cognitive processes in verbal-number production: inferences from the performance of brain-damaged subjects

This article presents a model of the cognitive processes involved in the spoken production of verbal numbers (e.g., thirteen thousand four hundred two). On the basis of single-case studies of two brain-damaged subjects with number production deficits, we argue that verbal-number production involves the generation of a syntactic frame that constitutes a plan for the production of the appropriate sequence of words. The syntactic frame specifies each to-be-retrieved word in terms of a number-lexical class (i.e., ones, teens, or tens) and a position within that class. These class/position-within-class specifications guide the retrieval of lexical representations from a production lexicon that is partitioned into functionally distinct ones, teens, and tens classes. We conclude with a brief discussion of the rationale for, and advantages of, using patterns of impaired performance as a basis for drawing inferences about normal cognition.

Cognitive processes in verbal-number production: Inferences from the performance of brain-damaged subjects

This article presents a model of the cognitive processes involved in the spoken production of verbal numbers (e.g., thirteen thousand four hundred two). On the basis of single-case studies of two brain-damaged subjects with number production deficits, we argue that verbal-number production involves the generation of a syntactic frame that constitutes a plan for the production of the appropriate sequence of words. The syntactic frame specifies each to-be-retrieved word in terms of a number-lexical class (i.e., ones, teens, or tens) and a position within that class. These class/position-within-class specifications guide the retrieval of lexical representations from a production lexicon that is partitioned into functionally distinct ones, teens, and tens classes. We conclude with a brief discussion of the rationale for, and advantages of, using patterns of impaired performance as a basis for drawing inferences about normal cognition.

Misleading postevent information and memory for events: arguments and evidence against memory impairment hypotheses

The claim that a person's memory for an event may be altered by information encountered after the event has been influential in shaping current conceptions of memory. The basis for the claim is a series of studies showing that subjects who are given false or misleading information about a previously witnessed event perform more poorly on tests of memory for the event than subjects who are not misled. In this article we argue that the available evidence does not imply that misleading postevent information impairs memory for the original event, because the procedure used in previous studies is inappropriate for assessing effects of misleading information on memory. We then introduce a more appropriate procedure and report six experiments using this procedure. We conclude from the results that misleading postevent information has no effect on memory for the original event. We then review several recent studies that seem to contradict this conclusion, showing that the studies do not pose problems for our position. Finally, we discuss the implications of our conclusions for broader issues concerning memory.