Human Eyeblink Classical Conditioning: Effects of Manipulating Awareness of the Stimulus Contingencies

Obsessive-compulsive disorder (OCD) is an intrusive and debilitating condition in which the individual experiences uncontrollable thoughts, compulsions, and urges. Successful treatments for OCD are based on Mowrer's theory of fear and avoidance behavior, which predicts that OCD subjects should show accelerated associative conditioning. This prediction was tested in two experiments that com-pared the classical eyeblink conditioning of OCD-like and control college students. OCD and control subjects learned normally and similarly when the conditioning procedure was accompanied by an active visual search background task (Experiment 1). However, when the background task was changed so that subjects passively viewed neutral pictures, OCD subjects conditioned significantly faster than control subjects (Experiment 2). Overall, the performance of all subjects in Experiment 1 was superior to the performance of subjects in Experiemnt 2.     

Age-related changes in the associations of social network ties with mortality risk

Age-related changes in the associations of social network ties with mortality risk were investigated using data from the Terman Life-Cycle Study (L. M. Terman, 1925; L. M. Terman & M. H. Oden, 1947, 1959). Marital status, number of living children, number of living siblings, and number of group memberships in 1940, 1950, 1960, and 1977 were reported across middle adulthood by 697 men and 544 women, with mortality follow-up as of 1991. Initial analyses confirmed previous work indicating that marital history (men only), number of children (both genders), and organizational memberships (both genders) are predictive of mortality risk. Further analyses compared the associations between these social ties and mortality prior to age 70 and at age 70 and older. Results indicated that for men, experiencing marital dissolution and subsequently remarrying is a stronger predictor of mortality risk prior to age 70 (p = .05), whereas for women, number of children (p < .05) is a stronger predictor of mortality risk after age 70. Implications of these age-related changes in social ties and mortality risk are discussed.     

Apraxia differs in corticobasal degeneration and left-parietal stroke: A case study.

Corticobasal degeneration (CBD) is a progressive disorder characterized by both cortical and basal ganglia dysfunction such as asymmetrical apraxia, and akinetic rigidity, involuntary movements, and cortical sensory loss. Although apraxia is a key finding for the differential diagnosis of CBD, it has not been determined whether the features of apraxia seen in subjects with CBD are similar to those features exhibited by subjects with left-hemisphere damage from stroke. Therefore, for both clinical purposes and in order to better understand the brain mechanisms that lead to apraxia in CBD, we studied praxis in a patient with CBD and compared him to patients who are apraxic from left-parietal strokes. We used three-dimensional movement analyses to compare the features of apraxic movement. This subject with CBD was a dentist whose initial complaint had been that he "forgot" how to use his tools in the mouths of his patients. Analyses were performed on the trajectories made when using a knife to actually slice bread, and when repetitively gesturing slicing made to verbal command. Movements of the left hand, wrist, elbow, and shoulder were digitized in 3-D space. Although the CBD subject was clearly apraxic, the features of his apraxia differed markedly from those of the subjects with lesions in the left parietal lobe. For movements to command, the CBD subject showed joint coordination deficits, but his wrist trajectories were produced in the appropriate spatial plane, were correctly restricted to a single plane, and, like control subjects, were linear in path shape. However, when he was actually manipulating the tool and object, all of these aspects of his trajectories became impaired. In contrast, the deficits of the apraxic subjects with left-parietal damage were most pronounced to verbal command with their movements improving slightly although remaining impaired during actual tool and object manipulation. Unlike patients with parietal strokes, patients with CBD have degeneration in several systems and perhaps deficits in these other areas may account for the differences in praxic behavior.     

Generating fixed-length sequences satisfying any givennth-order transition probability matrix

An experimental design involving sequences ofm distinct events can be conceptualized as annthorder transition probability matrix specifying the probabilities with which each of themdistinct events is to follow certainn-grams. This paper describes a general method for constructing sequences of shortest possible length that satisfy any such matrix and presents a computer program that randomly generates such sequences.     

Experimental pragmatics and what is said: a response to Gibbs and Moise

Gibbs and Moise [Gibbs, R., Moise, J., 1997. Pragmatics in understanding what is said. Cognition 62, 51-74], present experimental results which, they claim, show that people recognize a distinction between what is said and what is implicated. They also claim that these results provide support for theories of utterance interpretation (such as Relevance Theory) which recognize that pragmatic processes are involved not only in understanding what is implicated but also in working out what is said (the 'explicature'). We attempted to replicate some of these experiments and also adapted them. Our results fail to confirm Gibbs and Moise's claims. Most significantly, they show that, under certain conditions, subjects select implicatures when asked to select the paraphrase that best reflects what a speaker has said. We suggest that our results can be explained within the framework of Relevance Theory (Sperber, D., Wilson, D., 1986. Relevance: Communication and Cognition. Blackwell, Oxford) if we assume that subjects select the paraphrase that comes closest to achieving the same set of communicated contextual effects as the original utterance. When an utterance gives rise to a single strong implicature, subjects tend to select this as the paraphrase that best reflects what is said; in other cases (for example in Gibbs and Moise's stimuli) subjects tend to select the explicature.     

Maternal employment and development of the father-infant relationship in the first year.

This study investigated links between maternal employment and fathers' parenting quality when their infants were 4 and 12 months old. Sixty-three fathers were videotaped interacting with their infants and completed questionnaires regarding their involvement in caregiving, parenting stress, and marital quality, and mothers reported on children's temperament. Fathers whose wives either did not work outside the home or worked part time were more sensitive and responsive to their children when they were more involved in caregiving; men whose wives worked full time exhibited more negative affect and behavior when they participated more in child care. Men whose wives were not employed also were more positive in their interactions when they were happier with their marriage, whereas men whose wives worked either part time or full time exhibited a negative relation between parenting behavior and marital quality. Maternal work circumstances were not related to fathers' parenting stress; rather, marital quality and child temperament predicted parenting stress at 4 and 12 months for all fathers.     

Neuropsychological performance of emotionally disturbed students on the LNNB and LNNB-C

A number of researchers have reported an association between neuropsychological impairment and psychiatric disorders. However, there has been relatively little research on the neuropsychological functioning of emotionally disturbed students served in public schools. The purpose of this study was to determine the neuropsychological performance of 65 emotionally disturbed students 8–18 years old on the Luria-Nebraska Neuropsychological Battery: Form I (LNNB) and the Luria-Nebraska Neuropsychological Battery: Children's Revision (LNNB-C). The results indicated that approximately 42% of the younger group (99–154 months) and 38% of the older group (156– 226 months) demonstrated neuropsychological impairment as defined by criterion values for the various scales of the two batteries. On average, the emotionally disturbed students appeared to demonstrate more difficulty on more complex cognitive tasks, such as writing, arithmetic, and intellectual processes, than for less complex tasks, such as motor functions.