The octopus in the laboratory. Handling,maintenance, training

Octopus maya lives well for long periods in a small tank containing a plastic house in which it can be carried without disturbance to and from an experimental situation. Data are reported on the growth of animals kept under these conditions as a function of feeding schedule and on their food intake as a function of deprivation. Some animals were trained in a runway with food as reward, and others were trained in a simple maze with return to sea water as reward.     

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).