Quest: A Bayesian adaptive psychometric method

An adaptive psychometric procedure that places each trial at the current most probable Bayesian estimate of threshold is described. The procedure takes advantage of the common finding that the human psychometric function is invariant in form when expressed as a function of log intensity. The procedure is simple, fast, and efficient, and may be easily implemented on any computer.     

Aphasia following a right thalamic hemorrhage

A left-handed patient with a right thalamic hemorrhage and disordered speech is described. Sequential examinations and aphasia testing were done during a 1-year follow-up period and the results are reported. This case supports those authors who have described characteristics they feel are helpful in diagnosing disordered speech associated with thalamic lesions. Paucity of speech, reduced voice volume, anomia, some paraphasia, and severe dysgraphia were present, but comprehension and repetition were relatively preserved. She showed modest improvement with time. This case also confirms that thalamic involvement in speech is a dominant, rather than a specifically left hemispheric function.     

Mood and the self-reference bias in recall

Hypotheses linking a negative recall bias (or negative self-schema) with vulnerability to depression were tested using an experimental mood-induction task. Extent of bias in student subjects was found to be unstable over a 4-month period, but different measures of memory bias within one session were highly correlated. Marginally significant correlations in the expected direction were found between estimates of recall bias and mood state, whether measured at the same or at different times. Change in mood following induction did not relate to change in bias, suggesting that the observed differences in recall are not a simple function of transient mood state alone. Equally, the initial recall bias did not predict the extent of mood shift following induction, as would be expected if a negative self-schema determined ease of mood shift in a negative direction. However, significant correlations were found between negative recall bias and self-reported frequency and severity of depression, lending equivocal support to the negative self-schema model.     

The effects of hand and direction parameter preknowledge on choice reaction times

The two studies undertaken investigated how reaction times are affected by preknowledge concerning hand and direction parameters, and the order in which these data are disclosed. In the first experiment, preknowledge was manipulated by selecting 2-CRT pairs which had either a common hand or direction component. Reaction signal information content (as defined by the number of unknown response parameters) was controlled, but no parameter differences emerged. When parameter order was manipulated by sequential precuing, the ‘hand then direction’ order conferred a significant advantage. Motor preparation and response selection explanations for this effect are considered. Various difficulties with the paradigms used are discussed, including those of distinguishing between response selection and motor programming contributions, controlling and inferring the strategies adopted by subjects, and defining task difficulty. The prospects for independently fostering either response identification or motor preparation by means of an appropriate selection of precues are also discussed.     

Effects of background anger,provocation, and methylphenidate on emotional arousal and aggressive responding in attention-deficit hyperactivity disordered boys with and without concurrent aggressiveness

We investigated the effects of background anger, provocation, and methylphenidate on emotional, physiological, and behavioral responding in children with attentiondeficit hyperactivity disorder (ADHD) with and without concurrent aggression. Our study revealed that ADHD boys showed more emotional and physiological distress when exposed to an interaction in which an administrator chastised each boy's favorite counselor, compared to a friendly interaction between the two adults. The background anger manipulation did not affect the aggressive behavior of the boys against an opponent in an aggressive game. High-aggressive (HA) ADHD boys were more likely to respond to provocation with aggression than low-aggressive (LA) ADHD boys, but only LA boys showed increased physiological reactivity with increasing provocation. Methylphenidate resulted in increased heart rates under all conditions and did not interact with any of the other findings.This project was conducted while the first author had the support of National Institute of Alcohol Abuse and Alcoholism grant AA 06267.The authors wish to thank the staff members of the 1987 Summer Day Treatment Program who assisted in conducting this project. The authors also express their appreciation to Karen Guthrie for coordinating the medication assessment and to Hart Blanton for computer programming.     

Assessment of delusional beliefs during the modification of delusional verbalizations

This study examined the strength of delusional beliefs during the modification of delusional verbalizations of a 51 year-old chronically mentally ill inpatient. The changing-criterion design was used to document the effectiveness of a behavioral treatment package to alter the rate of delusional responses to personal background questions. The results revealed a stepwise decline in the frequency of delusional responses. Generalization effects to novel interviewers were obtained. No changes were obtained on the subject's ratings of delusional beliefs, with the subject assigning ratings of absolute conviction to his beliefs throughout the duration of the study.     

A study of language functioning in Alzheimer patients

Language functioning in Alzheimer's disease is reviewed and the performance of 25 Alzheimer patients on a standard battery is reported. All these hospitalized patients were aphasic to some degree. As a group, they differed from normals on all language variables, and from stroke patients in terms of higher fluency and lower comprehension. Spontaneous speech showed high incidence of circumlocutions and semantic jargon, but no phonemic paraphasias or target approximations. Syllabic perseverations, shouting, inappropriate laughter, and mutism were late-appearing features. Transcortical Sensory, and Wernicke's aphasias were frequent, but Broca's and Transcortical Motor aphasias notably absent. Extent of language impairment correlated with current length of hospitalization but not age. Reading, writing, and performance scores except praxis, were lower than oral language scores. Findings were discussed in relation to previous results, methodology, and language organization in the brain.