Language and problem solving ability: A comparison between deaf and hearing adolescents

Two groups of subjects, one deaf and one hearing, were tested in pairs on problem solving tasks. The poorer performance of the deaf observed in other studies has been explained as due to difference in language ability between the two groups. This finding was not replicated in the present study where use of language was required to solve tasks of different complexity. It is suggested that sign language may be as effective a tool for problem solving as spoken language. The postulated supremacy of spoken language to other forms of communication with regard to logical and symbolic functioning is thus questioned.     

Aversive and compensatory classical conditioning with diazepam as conditional stimulus

The purpose of the first experiment was to investigate whether diazepam could acquire anxiogenic properties by signalling an aversive event. Rats were trained in an operant chamber in the pentylenetetrazol (PTZ) model of anxiety. Thereafter the animals were divided into groups that received classical diazepam conditioning (Group 1), and conditioning of diazepam + tone (Group 2). In the test phase diazepam was injected prior to placement in the operant chamber. Group 2 selected the PTZ-appropriate lever more often than the other groups, indicating that the tone induced anxiety, and diazepam did not. Tones and shock may therefore be more easily associated than diazepam and shock. The second experiment investigated this. Rats were trained the same way as in the first experiment. Thereafter the experimental group received injections of a small dose of diazepam prior to a second injection of a large dose of diazepam. The hypothesis was that a compensatory anxiogenic conditional response to diazepam's anxiolytic effect should be elicited by the small dose. There were no differences between the groups in lever selection, indicating that a compensatory anxiogenic response was not elicited.     

Drug effects: Agonistic and antagonistic processes

The research presented here has shown that tolerance to drugs can be accelerated by conditioning processes. Placebo effects may be considered the opposite of tolerance, and we have shown that placebo effects may be objectively recorded by physiological measures (electromyography, skin conductance responses, and event‐related potentials), as well as by behavioral and subjective methods. The placebo response, or more precisely, the expectation of drug effects, can add to the effect of the drug. Drug antagonistic expectations can also reverse the effect of the drug. There is some evidence that placebo effects are strongest when expectations are reinforced by administration of an active drug. Expectations have graded effects and may affect symptoms to a smaller or larger degree. Although drug effects can be considered stimuli, the investigation of the role of classical conditioning in drug use and drug effects involves special issues that must be carefully considered.     

Hemispheric asymmetry effects in children studied by dichotic listening and visual half-field testing

Dichotic listening (DL) and visual half-field (VHF) testing were used to study hemisphere asymmetry in a developmental perspective. Five-, 8-, and 11-year-old children were presented lists of fused words using a DL technique in Experiment 1, and 8- and 11-year-old children were presented pictures of common objects using a VHF technique in Experiment 2. In both experiments, measures of identification, free recall, and recognition of the words/pictures were employed. The results revealed effects of ear input (right-ear advantage) and half-field presentation (right visual half-field advantage) for all age groups, although the magnitude of this lateralization effect differed between the three memory measures. The results are discussed in relation to developmental aspects of language laterality, and in relation to the clinical utility of non-invasive lateralization techniques.