A note on further experiments on the effects of meprobamate on discrimination performance in the monkey

A previous experiment (Gross and Weiskrantz, 1961) has shown that performance on a successive auditory discrimination task is impaired by injections of meprobamate. The present two brief experiments indicate that the drug also impairs simultaneous visual discrimination performance, although not to the same degree as found earlier for auditory discrimination. The original finding, therefore, cannot be attributed simply to unique features of the auditory discrimination situation, such as the “go—no-go” response contingency. Since neither overtraining nor drug habituation appears to be of great importance, it is suggested that the lesser effect of the drug in these experiments reflects the greater stability of visual than auditory habits in the monkey.

Earlier work has shown that meprobamate and reserpine can cause a severe deterioration in auditory discrimination performance of monkeys (Gross and Weiskrantz, 1961). This result was taken as supporting a hypothesis, growing out of still earlier research, that tranquillizers decrease the utilization of sensory information (Weiskrantz and Wilson, 1956; Weiskrantz, 1957).

The auditory task, as is almost always the case with monkeys as subjects, involved a “go—no-go” type of response contingency—i.e. the animal had to respond to the positive stimulus and had not to respond to the negative stimulus in order to achieve reward. It might be objected, therefore, that the deterioration in performance was associated not with discrimination as such but with the animals' willingness to perform at all. In fact, it was found that the animals tended to make most of their errors under the drugs by responding when they should not rather than not responding when they should.

The purpose of the present experiments, therefore, was to test the animals with a visual discrimination task in which both the positive and negative stimuli were presented simultaneously. An effect of the drug could not, in this situation, be characterized simply as altering the responsiveness of the animal. A further purpose in using visual stimuli was to test the generality of the earlier finding in a sense modality other than audition.     

Behavioral case formulation: An experimental assessment study of transient tic disorder

A nine-year-old male, who met DSM III-R criteria for transient tic disorder, participated in an experimental assessment strategy to generate support for a case formulation. In addition to presenting motor disturbance, assessment procedures revealed six problem areas. All problems were formulated as manifestations of a hypersensitivity to evaluation, etiologically related to the boy's relationship with an insecure and critical father. It was hypothesized that the patient's tic disorder was a consequence of his hypersensitivity to father's excessive criticism, which then generalized to other evaluative situations. Using a controlled single-subject design, predictions derived from the formulation were tested by exposing the child to a planned combination of evaluative observers (e.g., father, mother, therapist, etc.) who watched him as he worked on a series of puzzles. The dependent measures included (1) behavioral recordings of tic frequency and (2) frontalis EMG responses. The results indicated significant differences in tic rate and EMG as a function of the type of observer. Consistent with the formulation, the patient displayed the highest levels of tic behavior and EMG response when his father was the observer and lowest in the presence of the mother. Predictions regarding other stimulus conditions were also confirmed. These results provided support for the case formulation that was used to design an effective treatment intervention. Findings suggest that the case formulation model offers a method whereby novel case hypotheses can be generated for poorly understood psychopathology and tested later in the experimental situation.     

The etiology of schizophrenia as perceived by psychiatrists in Europe and the United States

This paper compares and contrasts statements made by American and European psychiatrists on the etiology of schizophrenia. In the U.S., leading figures in psychiatry hold increasingly to the view that the disorder is physiogenic at source—from which it seems to follow that the appropriate treatments should similarly focus on physiological and pharmacological therapies. In contrast, European psychiatrists seem to be divided in support for organic and psychodynamic explanations. Some European writers have pointedly warned against over-interpreting recent studies which seem to point to specific organic dysfunctions and deficits as schizophrenogenic. This paper was presented at the Second Annual Convention of the American Psychological Society, Dallas, Texas, June 7–10, 1990.     

Racial Identity Development Among Gifted Black Students: Counseling Issues and Concerns

A review of the literature suggests that a paucity of information exists regarding how culture-specific issues such as being both Black and gifted influence the psychological needs and personality development of gifted Black students. Stellar attempts, however, are currently underway to develop theories and perspectives of racial identity development among Black students. These theories and perspectives are discussed in an attempt to understand and address the psychological and social needs of gifted Black students.     

Dynamic spatial performance and general intelligence

A computerized video-game-like dynamic spatial ability measure and a paper-and-pencil group test of intelligence were administered to 94 university students. The purpose of the study was threefold: (a) to evaluate the reliability of the dynamic spatial measure; (b) to investigate the extent to which the dynamic spatial measure is saturated with variance associated with traditional measures of fluid and crystallized intellectual ability; and (c) to explore the possibility that dynamic computer based performance measures define factors that are distinct from those associated with traditional paper-and-pencil measures. The number of times the participant hit a moving target served as the dependent variable for the dynamic spatial measure. Number of hits proved to be correlated with Performance IQ, but was not significantly correlated with Verbal IQ. Maximum likelihood factor analysis revealed that the dynamic spatial measure did not load substantially on a factor of general intellectual ability but provided additional evidence that it is related to a performance component.     

Search behaviour of cats (Felis catus) in an invisible displacement test: cognition and experience

An invisible displacement test was administered to cats in order to test the hypothesis that search behaviour in this species is influenced by their limited capacity for object permanence as well as by their previous experience with the environment. Experiment 1 compared three groups of cats in a five-choice hiding task in which the hiding places could be discriminated by their spatial positions. Two groups received a visible displacement training before the invisible displacement test and one group did not. Experiment 2 compared two groups of trained subjects in the same task, but the hiding places could be discriminated by spatial and visual cues. The results confirmed that cats are unable to solve problems with invisible displacements. The visible displacement training improved their performance, but was not sufficient to make them succeed. Experience with the hiding potential of the covers also gives more persistence to search behaviour. Finally, the distribution of search attempts is not determined by the proximity to the target and is influenced only partially by the subjects' previous experience. Like Stage 5 infants, cats rely mainly on their immediate perception. They search for an object in the last location they have seen it disappear or under the nearest cover from this location.     

Impact of practice on speed of mental rotation

We tested 11- and 20-year-olds on 3360 trials of a mental rotation task in which they judged if stimuli presented in different orientations were letters or mirror images of letters. Children's and adults' processing times decreased substantially over practice. These changes were well characterized by hyperbolic and power functions in which most of the parameters of those functions were constrained to adults' values. Performance on two transfer tasks, mental rotation of letter-like characters and memory search for numbers, indicated that the practiced skill did not generalize to other domains. The results are discussed in terms of different mechanisms that might be responsible for the impact of practice.     

Temporal learning in 4 1/2- and 6-year-old children: role of instructions and prior knowledge

The present study investigates effects of different types of instructions (high-rate, interval, and minimal) during training with a fixed-interval schedule as a function of prior acquired temporal knowledge. A pretest was used to assess 4 1/2- and 6-year-old children's ability to understand the temporal parameters of a fixed-interval schedule of reinforcement. The results as a whole show that the control exerted by instructions given by the experimenter or elaborated by the subjects themselves on fixed-interval performance of young children depends on the interaction of two factors: development of verbal self-control skills and mastery of knowledge required by the rules forming the instructions.     

Grading the ‘cultural literacy’ project

The essay examines the argument advanced by E.D. Hirsch, Jr., for instituting ‘cultural literacy’ as a fundamental priority of schools. A number of confusions and equivocations in Hirsch's reasoning are identified, and the propensity of his project to indoctrinate is exposed. Among the features of Hirsch's argument shown to be troubling are his shifting construal of ‘language’, his inconsistency about the requirements of cultural literacy, and his uncritical relation to traditional images of the American past and present. The upshot is to raise the question why Hirsch's project has elicited wide support and praise.     

Naming consistency in Alzheimer''s disease

Although lexical semantic deficits are postulated to play a prominent role in the anomia of Alzheimer's disease, it is unclear whether the primary disturbance is one of lexical access or one of lexical semantic loss. Response consistency on a naming task is one means of evaluating the underlying source of naming impairment. Access dysfunction usually implies variable word-finding difficulty, while a theory of lexical loss predicts that many word names would be consistently unavailable. Nineteen Alzheimer's disease patients were administered a visual confrontation naming task (the Boston Naming Test) on two occasions 6 months apart. Eighty percent of errors occurred consistently at both times; only 20% of errors occurred on only one occasion. Response consistency occurred significantly more often than expected under the assumption of no response consistency. Findings support the hypothesis that anomia in Alzheimer's disease is in part due to a loss of lexical semantic information.