A runway for the cockroach

A runway and training procedure that minimizes handling is described. Acquisition and extinction trials are presented to illustrate the technique.     

Methylphenidate and stimulus control of avoidance behavior

The introduction of a warning signal that preceded a scheduled shock modified the temporal distribution of free-operant avoidance responses. With response-shock and shock-shock intervals held constant, response rates increased only slightly when the response-signal interval was reduced. The result is consistent with Sidman's (1955) findings under different conditions, but at variance with Ulrich, Holz, and Azrin's (1964) findings under similar conditions. Methylphenidate in graded doses increased response rates, modifying frequency distributions of interresponse times. Drug treatment may have disrupted a "temporal discrimination" formed within the signal-shock interval. More simply, methylphenidate influenced response rates by increasing short response latencies after signal onset; this effect was more prominent than the drug's tendency to increase the frequency of pre-signal responses. When signal-onset preceded shock by 2 sec, individual differences in performance were marked; methylphenidate suppressed responding in one rat as a function of increasing dose levels to a greater degree than in a second animal, but both subjects received more shocks than under control conditions.     

Intellectual, mnemonic, and frontal functions in dementia with Lewy bodies: A comparison with early and advanced Parkinson's disease

Both Parkinson's disease (PD) and dementia with Lewy bodies (DLB) share a common neuropathological marker, the presence of Lewy bodies in brain stem and basal forebrain nuclei. DLB, in addition, is associated with Lewy bodies in the neocortex, and, in it's more common form, with Alzheimer-type pathological markers, particularly amyloid plaques. Published neuropsychological studies have focused on the differential profiles of DLB and Alzheimer's disease (AD). However, it is presently unclear whether DLB should be classified as a variant of AD or PD. In the present study we compare a healthy age-matched control group with three groups of patients, one with DLB, and two with PD. One of the PD groups was early in the course (PD-E) and the second, more advanced group (PD-A), was matched on severity of cognitive impairment with the DLB group. The results show that DLB was associated with a different pattern of neuropsychological impairment than the PD-A group, particularly in tests believed to be mediated by prefrontal cortical regions.     

Dispositional Optimism in Chinese People: What Does the Life Orientation Test Measure?

The Life Orientation Test was back-translated to Chinese and administered to a sample of college students (N = 314) and a sample of normal adults (N = 306) along with measures of personality and symptoms. When subject to factor analysis, the positive items (representing optimism) and the negative items (representing pessimism) emerged as two separate factors. Empirically, optimism and pessimism were moderately correlated and had unique contributions to the explanation of personality and symptom measures, so that the total score of C-LOT was a better predictor of criterion measures than either optimism or pessimism alone. However, C-LOT's relationship with symptoms was eliminated after negative affectivity was controlled in the student sample, but not in the adult sample, thus suggesting some confounding with negative affectivity. Further research is required to improve the measurement of optimism in Chinese people and to clarify the relationship between optimism and pessimism.     

The Place of Poetry in Gerontological Social Work Education

This essay focuses on poetry as a means to enhance the education and training of social workers and allied health care professionals working with the elderly. The poetry examined includes published popular poetry and poetry created by the elderly in community and residential programs. Finally, I discuss the poetry and narrative of four social workers as an integrative device for dealing with personal and professional issues relating to aging and identity.     

Microworlds for experimental research: Having your (control and collection) cake, and realism too

Microworlds (MWs) are dynamic computer-generated environments that subjects interact with in the laboratory and that simulate conditions encountered in the field. Precise levels of experimental control and improved accuracy and efficiency of data collection procedures are characteristic of MWs. It is proposed that these benefits are achieved with concomitant gains in internal validity (afforded by high levels of experimental realism) and external validity (afforded by the replication of the temporal-interactive nature of most field phenomena). To illustrate these ideas, three sets of MW studies are described that investigated rumor and behavior in the stock market (Broker), escalation behavior (Inve$tment Choice$), and the application of foraging theory to internet shopping (Cybershopper).     

Spatial selection via feature-driven inhibition of distractor locations

The allocation of spatial attention was measured with detection probes at different locations. Response times were faster for probes at the location of the target digit, which subjects reported, than at the locations of distractor digits, which they ignored. Probes at blank locations between stimuli produced fast responses, indicating that selection was accomplished by inhibiting distractor locations but not other areas. Unlike earlier studies using location cuing with simpler stimuli, these experiments showed no attentional differences across horizontal or vertical midlines. Attention varied little with distance from the target, although blank locations far from the target were somewhat less attended than were those near the target, and attention was only slightly affected by expectations for stimulus location. This task demonstrates a form of feature-driven spatial attention, in which locations with objects lacking target features are inhibited.     

Effects of high-pass and low-pass spatial filtering on face identification

If face images are degraded by block averaging, there is a nonlinear decline in recognition accuracy as block size increases, suggesting that identification requires a critical minimum range of object spatial frequencies. The identification of faces was measured with equivalent Fourier low-pass filtering and block averaging preserving the same information and with high-pass transformations. In Experiment 1, accuracy declined and response time increased in a significant nonlinear manner in all cases as the spatial-frequency range was reduced. However, it did so at a faster rate for the quantized and high-passed images. A second experiment controlled for the differences in the contrast of the high-pass faces and found a reduced but significant and nonlinear decline in performance as the spatial-frequency range was reduced. These data suggest that face identification is preferentially supported by a band of spatial frequencies of approximately 8-16 cycles per face; contrast or line-based explanations were found to be inadequate. The data are discussed in terms of current models of face identification.     

Work and Family Variables, Entrepreneurial Career Success, and Psychological Well-Being

The study examines the influence of work and family variables on the career success and psychological well-being of 111 men and women entrepreneurs. The results show that work-domain variables account for significant variation in time commitment to work, whereas family-domain variables explain substantial variation in time commitment to family. Time commitment to work and time commitment to family play an important role in mediating the effects of gender, work and family characteristics, and role demands on work-to-family conflict and family-to-work conflict. These two types of work–family conflict in turn mediate the effects of time commitment to work and family and selected work and family variables on entrepreneurs’ career success and life stress. Implications of the findings and directions for further research are discussed.