Right-sided human prefrontal brain activation during acquisition of conditioned fear

This H2(15)O positron emission tomography (PET) study reports on relative regional cerebral blood flow (rCBF) alterations during fear conditioning in humans. In the PET scanner, subjects viewed a TV screen with either visual white noise or snake videotapes displayed alone, then with electric shocks, followed by final presentations of white noise and snakes. Autonomic nervous system responses confirmed fear conditioning only to snakes. To reveal neural activation during acquisition, while equating sensory stimulation, scans during snakes with shocks and white noise alone were contrasted against white noise with shocks and snakes alone. During acquisition, rCBF increased in the right medial frontal gyrus, supporting a role for the prefrontal cortex in fear conditioning to unmasked evolutionary fear-relevant stimuli.     

Effects of family interaction on the child's behavior in single-parent or reconstructed families

The effects of the family interaction on children's behavior were studied in single-parent or reconstructed families (N = 63) in a white population in Finland. The focus was on the spousal and the parent-child interaction. Teachers assessed children's behavior and parents were interviewed. The interviews were analyzed qualitatively using the grounded-theory method. The boundary ambiguity theory developed by Pauline Boss was used to examine the interaction in the families. About two fifths of the parents reported that their spousal interaction was good, family boundaries were clear, and the children were taken care of together. Another two fifths interacted only because of the child and family boundaries were ambiguous. In 14 families the involvement of the noncustodial parent was both physically and psychologically low. The physically close but psychologically distant parent-child interaction seemed to affect the child's behavior detrimentally, whereas children with physically and psychologically close interaction with their parents showed less behavioral problems. The children with behavioral problems were more likely to have problems with both parents. They were also more likely to have a stepparent with whom they had conflicts. In conclusion, a good interaction between the parents and clarified family boundaries protect children's mental health after their parents' divorce or separation.     

Effects of mand-tact versus tact-only training on the acquisition of tacts

We sought to replicate and extend Carroll and Hesse's (1987) study of the acquisition of tacts by including participants with and without developmental disabilities. As in Carroll and Hesse, the present results showed that mand-tact training, rather than tact-only training, led to more rapid acquisition of tacts. Tacting on follow-up tests did not differ. In addition, our results show that mand-tact training established both verbal operants involved about as rapidly as tact-only training established only one verbal operant. DESCRIPTORS: verbal behavior, tact acquisition, mand-tact training, tact-only training, follow-up     

Psychological characteristics of elderly insomniacs

Sixty insomniacs, aged 60 years or over, fulfilling the DSM-IV criteria for primary insomnia, completed a set of questionnaires measuring psychological distress. These included the Sleep Impairment Index (SIM), the Symptom Check List 90-Revised (SCL-90-R), the Penn State Worry Questionnaire (PSWQ), the Toronto Alexithymia Scale-20 (TAS-20) and the Elders Life Stress Inventory (ELSI). The insomniacs were compared on these measures with two contrast groups, one of elderly good sleepers and one an elderly community sample. As norms were developed for the SCL-90-R and PSWQ, insomniacs were also contrasted with the norm groups on these measures. In general, the results indicated a higher level of psychological distress among insomniacs than among the good sleepers, while there were negligible differences between insomniacs and the community sample on most measures. Overall, elderly insomniacs scored higher on measures of worry compared with the other groups, followed by measures of somatization, obsessive-compulsion and depression. It is concluded that excessive worrying was the most characteristic feature of elderly insomniacs.     

Personal names and the human right hemisphere: an illusory link?

Names are thought to be represented in the brain differently from common nouns. Although this idea is supported by both theoretical and empirical arguments, the brain areas that are relevant for the recognition of personal names-and in particular the extent of right hemisphere involvement-remain controversial. We investigated the hypothesis that, unlike common nouns, personal names are represented preferentially by the right hemisphere (D. Van Lancker, 1991; D. Van Lancker et al., 1991; C. Ohnesorge & D. Van Lancker, 1999). Participants performed lexical decisions to common nouns and pseudowords (Experiment 1) or familiarity decisions to personal names (Experiment 2), which were presented briefly to the left or right visual fields. Asymmetries were small or absent for both pseudowords and unfamiliar names. For familiar names, both reaction times and error rates revealed strong advantages for the right visual field/left hemisphere (RVF/LH), which were comparable to the asymmetries for nouns. Familiar personal names may be represented by brain systems that differ from those representing common nouns, but current evidence does not suggest a distinct contribution of the right hemisphere to these brain systems.     

Correlates of suicidal behaviors among Asian American outpatient youths

Medical record abstraction was conducted at an ethnic-specific mental health outpatient clinic to identify correlates of suicidal behaviors in a sample of 285 Asian American youths. Some risk factors, such as parent-child conflict and age, which have been associated with suicidality in majority group youths, predicted suicidality in this sample, whereas other risk factors, such as gender, did not generalize to this sample. Acculturation interacted with the risk factor of parent-child conflict to predict suicidality. Less acculturated Asian youths were at proportionally greater risk for suicidality under conditions of high parent-child conflict than were their more acculturated counterparts. This finding underscores the importance of culture as a context for determining the relevance of stressors for potentiating psychopathology.     

Returning the tables: language affects spatial reasoning

Li and Gleitman (Turning the tables: language and spatial reasoning. Cognition, in press) seek to undermine a large-scale cross-cultural comparison of spatial language and cognition which claims to have demonstrated that language and conceptual coding in the spatial domain covary (see, for example, Space in language and cognition: explorations in linguistic diversity. Cambridge: Cambridge University Press, in press; Language 74 (1998) 557): the most plausible interpretation is that different languages induce distinct conceptual codings. Arguing against this, Li and Gleitman attempt to show that in an American student population they can obtain any of the relevant conceptual codings just by varying spatial cues, holding language constant. They then argue that our findings are better interpreted in terms of ecologically-induced distinct cognitive styles reflected in language. Linguistic coding, they argue, has no causal effects on non-linguistic thinking--it simply reflects antecedently existing conceptual distinctions. We here show that Li and Gleitman did not make a crucial distinction between frames of spatial reference relevant to our line of research. We report a series of experiments designed to show that they have, as a consequence, misinterpreted the results of their own experiments, which are in fact in line with our hypothesis. Their attempts to reinterpret the large cross-cultural study, and to enlist support from animal and infant studies, fail for the same reasons. We further try to discern exactly what theory drives their presumption that language can have no cognitive efficacy, and conclude that their position is undermined by a wide range of considerations.     

Speech perception deficits in Parkinson's disease: underestimation of time intervals compromises identification of durational phonetic contrasts

Besides motor, vegetative, and cognitive signs, patients suffering from Parkinson's disease (PD) may show distinct perceptual deficits such as underestimation of time intervals extending across several seconds. Assuming this impairment also to affect the domain of tens of milliseconds, disrupted encoding of the acoustic speech signal with respect to segment durations conveying linguistic information must be expected. To test this hypothesis, 10 PD patients and matched controls performed an identification task using a series of 10 stimuli derived from the utterance "Boten" (/bo:tn/, 'messengers'; produced with nasal plosion) by exclusive manipulation of occlusion length (110-20 ms in steps of 10 ms). Under these conditions, word-medial silence cues the voicing category of the respective stop consonant. Seven PD subjects showed normal identification curves, i.e., categorized the shortest and longest stimuli with high probability each as the minimal pair cognates "Boden" and "Boten," respectively. In contrast, the remaining three patients labeled all items across the complete range of occlusion lengths as "Boden." A subsequent experiment found a horizontal shift of the identification curves toward larger signal durations (> 120 ms) in these three subjects. Bilateral cerebellar degeneration has been found to yield a different response pattern, i.e., near-chance level of performance. Considering recent information-processing models of scalar interval timing, striatal disorders seem to slow down an oscillatory pacemaker, whereas cerebellar dysfunctions may impair comparison of measured durations with stored reference memory traces.     

At what age do children learn to discriminate between act and actor?

Children's ability to make moral judgements about an act on the basis of aspects of the act rather than on liking and preconceived ideas about the actor was investigated. 85 children of 4 age groups (preschool, Grades 1, 2, and 3, age range 5-9 years) participated. Act/Actor discrimination was investigated with a test consisting of 8 cartoons. In 4, a rabbit was behaving aggressively against a wolf; the other 4 portrayed identical acts with the wolf as aggressor and the rabbit as victim. Participants made moral evaluations of each cartoon. IQ was measured with Raven's Standard Progressive Matrices, and the general level of moral development was measured in accord with Piaget's (1932) criteria. Age, IQ, and general moral development correlated with discriminative ability for Act and Actor. In Piagetian terms, children at the heteronomous level were not capable of such discrimination, while children at the autonomous level (above 7 years of age) in general were.