Functional decline in the early stages of Alzheimer's disease

At present most reports of functional decline in patients with Alzheimer's Disease (AD) are anecdotal, and few studies have objectively documented the course of the disease. This is a report of a 2-year follow-up of 15 AD patients characterized by mild functional impairment, and 22 age-, sex-, and education-matched control subjects. In a previous cross-sectional study of these 37 subjects and 16 AD patients with moderate functional impairment, we found that measures of memory and attention deficits accounted for much of the impairment observed in functional competence. The current longitudinal study found that these same initial assessments could be used to predict functional decline in the 15 mildly impaired patients. These patients were observed to decline to levels similar to those of the 16 moderate patients. In contrast, the control subjects exhibited little decline during the same period. These results both affirm that it is possible to diagnose AD in its mild form and demonstrate the validity of the initial diagnosis.     

Effect of physical stimulation on motor inhibition in children

The effect of physical stimulation on motor inhibition and cognitive performance of 70 third-grade children was examined. 46 subjects participated in a brief, but strenuous obstacle course. Their performance on two motor inhibition tasks, a short-term memory/attentional task, and a test assessing reflectivity was assessed before the stimulation, immediately afterward, and again after a 30-min. delay. A control group (n = 24) received comparable experience without the physical intervention. Physical stimulation facilitated fine motor inhibition at both the immediate and delayed retest. The intervention interfered with an apparent practice effect on the attentional task. No condition effects were noted for gross motor performance or reflectivity, although girls were significantly more reflective at retest. It is proposed that physical stimulation augments certain aspects of inhibitory control in children.     

Back to the future: Temporal perspective in the explanation of events

Prospective hindsight involves generating an explanation for a future event as if it had already happened; i.e., one goes forward in time, and then looks back. In order to examine how shifts in perspective might influence people's perceptions of events, we investigated two possible factors: temporal perspective (whether an event is set in the future or past) and uncertainty (whether the event's occurrence is certain or uncertain). In the first experiment, temporal perspective showed little influence while outcome uncertainty strongly affected the nature of explanations for events. Explanations for sure events tended to be longer, to contain a higher proportion of episodic reasons, and to be expressed in past tense. Evidence from the second experiment supports the view that uncertainty mediates not the amount of time spent explaining, but rather subjects' choice of explanation type. The implications of these findings for the use of temporal perspective in decision aiding are discussed.     

Differences in reported symptom profile between panic disorder and other DSM-III-R anxiety disorders.

Previous research has indicated that reports of panic attacks are associated with a different set of symptoms to reports of generalized anxiety. The present two studies attempted to extend these findings to specific (situational) fears. In Study 1, 55 subjects with panic disorder were compared on their symptom profile during their panic attacks to 65 subjects with other anxiety disorders [simple phobia, social phobia and obsessive-compulsive disorder (OCD)] during response to their feared cue. The results indicated that, compared to subjects with other anxiety disorders, subjects with panic disorder were more likely to report parasthesias, dizziness, faintness, unreality, dyspnea, fear of dying and fear of going crazy/losing control. In Study 2, 90 subjects meeting diagnostic criteria for both panic disorder and another anxiety disorder (simple phobia, social phobia or OCD) were compared on the symptoms experienced during their unexpected panic attacks and their situationally-triggered fears respectively. Combining the symptoms found in Study 1 to differ between the groups into a linear combination, there was a significant interaction found between the type of fear reaction (panic attack vs cued fear response) and symptom group. Taken together, these findings suggest that reports of unexpected panic attacks associated with panic disorder are characterized by a different symptom profile to reports of specific fear reactions that are part of a phobic disorder or OCD.     

Buying a passport to heaven: Usury, restitution, and the merchants of medieval Genoa

Historians have argued that the ecclesiastic ban on loans at interest delayed the development of capital markets in the middle ages, and have supported this by pointing to well-documented cases of restitutions of usurious gains by famous moneylenders. Strictly, however, such evidence does not prove that usury laws affected lending, because donations by rich bankers may reflect other motivations. If usury laws had an impact, we have to exclude the Medicis or the Fuggers from the sample, and look for it among the small moneylenders of medieval Europe. Data from late medieval Genoa show that donations by merchants were no greater than those of the population at large once personal wealth is accounted for. However, among merchants the value of pious bequests correlates more closely with mercantile activity than personal wealth, a finding that supports the view that usury laws created an effective constraint on medieval capital markets.     

Test of the violation of local realism in quantum mechanics with no use of Bell's inequalities

A novel and versatile polarization-entanglement scheme is adopted to investigate the violation of the EPR local realism for a non-maximally entangled two-photon system according to the recent nonlocality proof by Lucien Hardy. In this context the adoption of a sophisticated detection method allows direct determination of any element of physical reality (viz., determined with probability equal to unity in the words of Einstein, Podolsky and Rosen) for the pair system within complete measurements that are largely insensitive to the detector quantum-efficiencies and noise.     

Detection of stimulus change: The hypothetical roles of visual transient responses

Two random-dot patterns (D1 and D2) were displayed briefly in close temporal succession, separated by an interstimulus interval (ISI). The two patterns were identical except that D2 could contain one more element (addition) or one less element (subtraction) than D1. Observers were required to detect the addition or subtraction using a two-alternative forced-choice method. Three experiments were designed to examine Phillips and Singer’s (1974) suggestion that detection of additions and subtractions can be explained in terms of neural ON and OFF responses. Experiment 1 replicated Phillips and Singer’s finding that performance is progressively impaired as the ISI is increased. In Experiment 2, sudden shifts in luminance between D1 and D2 were combined with several durations of ISI to produce transient responses in a novel manner. Experiment 3 explored the roles of transient neural responses and of configurational changes as determinants of performance. Most predictions based on Phillips and Singer’s model were confirmed by the experimental outcomes. Some discrepancies between theory and data are noted, and directions for further research are suggested.     

损毁下丘脑弓状核、中缝背核和蓝斑对大鼠应激镇痛的影响

本文用不能躲避的间歇脚底电刺激引起大鼠应激,用电刺激鼠尾-嘶叫法测定镇痛效应,研究下丘脑弓状核(脑内β-内啡肽能神经元胞体集中的部位)、中缝背核(脑内5-羟色胺能神经元胞体主要集中的部位之一)和蓝斑(脑内去甲肾上腺素能神经元胞体主要集中的部位之一)与应激镇痛的关系。 用新生大鼠腹腔注射谷氨酸-钠的方法损毁弓状核后,用海人酸和电解两种方法损毁中缝背核或蓝斑后,应激镇痛效应均明显减弱。由于谷氨酸-钠和海人酸只选择性地损毁神经元胞体,故认为脑内的β-内啡肽能神经元、5-羟色胺能神经元和去甲肾上腺素能神经元均参与应激的行为镇痛。