A randomized trial of a representational intervention to decrease cancer pain (RIDcancerPain).

OBJECTIVE: Based on theories regarding cognitive representations of illness and processes of conceptual change, a representational intervention to decrease cancer pain (RIDcancerPain) was developed and its efficacy tested. DESIGN: A two-group RCT (RIDcancerPain versus control) with outcome and mediating variables assessed at baseline (T1) and 1 and 2 months later (T2 and T3). Subjects were 176 adults with pain related to metastatic cancer. MAIN OUTCOME MEASURES: Outcome variables were two pain severity measures (BPI and TPQM), pain interference with life, and overall quality of life. Mediating variables were attitudinal barriers to pain management and coping (medication use). RESULTS: One hundred and fifty subjects completed the study. Subjects in RIDcancerPain (T1-T2 and T1-T3) showed greater decreases in Barrier scores than those in control. Subjects in RIDcancerPain (T1-T3) showed greater decreases in pain severity than those in control. Change in Barriers scores mediated the effect of RIDcancerPain on pain severity. CONCLUSION: RIDcancerPain was efficacious with respect to some outcomes. Further work is needed to strengthen it.     

Varieties of Binocular Interaction in Human Vision

Binocular processing was investigated using a quantitative, process-oriented metatheory of response times. The analyses are not confined to particular distributional assumptions or specific models. Upper and lower performance boundaries for probability summation in parallel processing are defined and compared with observed distributions of reaction times using a variety of dichoptic stimuli. Performance that exceeds the upper bound strongly suggests faciliatory convergence between the two eyes (binocular channel summation). Performance below the lower bound suggests that inputs to the two eyes are processed serially. The results indicate that binocular channel summation in subjects with normal stereo vision requires targets of the same luminance polarity (paired increments or decrements) in corresponding retinal locations. When corresponding retinal locations are stimulated with opposing luminance polarities (increment to one eye, decrement to the other), performance is consistent with probability summation, indicating that parallel ON and OFF pathways remain segregated at least to the level of binocular fusion. Further analyses of data from a stereo-blind observer suggests serial processing of binocular inputs.     

Acquisition of a non-vocal ‘language’ by aphasic children

Alphasic children with serious language deficits were taught to communicate via a system of visual symbols originally devised by David Premack (1969) for use with chimpanzees. The subjects, lacking normal language, readily learned to express several language functions in this way (word, sentence, class-concept, question, negation). The linguistic status of ‘Premackese’ is questioned, and it is suggested that it is better viewed as a communication system. It may, therefore, be that the aphasic children lack some specifically linguistic ability.     

Effects of time and event uncertainty upon sequential information processing

Two experiments were conducted to investigate the psychological refractory period (PRP), a delay induced into the second of two reaction times (RT) when the interstimulus interval (ISI) is short. In Experiment1, time and event uncertainty were factorially varied by providing or not providing S with foreknowledge of the ISI and the order in which the two events would occur, respectively. ISIs of0, 50, 100, 200, and400 msec were used. Time and event uncertainty produced independent degradation of both RTs. Also, the second RT (RT ₂ ) was delayed at50 msec ISI when both time and event certainty were present. Experiment 2 attempted to replicate this latter finding using ISIs of0, 25, 50, 75, and100 msec. Delays in RT ₂ were found for the middle three values of ISI. These results were interpreted as supporting a modified single channel theory of the PRP.     

Punishment of observing by the negative discriminative stimulus

To determine the effect of a negative discriminative stimulus on the response producing it, two pigeons were each studied in a three-key conditioning chamber. During alternating periods of unpredictable duration, pecking the center (food) key either was reinforced with grain on a variable-interval schedule or was never reinforced. On equal but independent variable-interval schedules, pecking either of the side (observing) keys changed the color of all keys for 30 sec from yellow to either green or red. When the schedule on the center key was variable-interval reinforcement, the color was green (positive discriminative stimulus); when no reinforcements were scheduled, the color was red (negative discriminative stimulus). Since pecking the side keys did not affect grain deliveries, changes in the rate of pecking could not be ascribed to changes in the frequency of primary reinforcement. In subsequent sessions, red was withheld as one of the possible consequences of pecking a given side key. When red was omitted, the rate on that key increased, and when red was restored, the rate decreased. It was concluded that red illumination of the keys, the negative discriminative stimulus, had a suppressive effect on the response that produced it.     

The temporal course of the frustration effect

General activity subsequent to reward (R) and nonreward (N) was monitored at 5-sec intervals with a stabilimeter in the runway goal box. Activity of never-rewarded control Ss was also measured. In Expt 1 it was found that the frustration effect (difference between N- and R-trial activities) disappeared after about 40 sec of goal box confinement. This disappearance of the frustration effect was due to activity increase on R trials rather than activity decrease on N trials as a function of time. Comparison of N-trial activity with control group activity indicated that frustration does not dissipate within 60 sec. Expt 2 investigated activity following reward and nonreward as a function of reward magnitude. Evidence from these experiments suggests that the late R-trial activity increase results from frustration, possibly conditioned to apparatus cues on N trials.