Hemispheric processing characteristics for lexical decisions in adults with reading disorders

The present study measured unilateral tachistoscopic vocal reaction times and error responses of reading-disordered and normally reading adults to single words and nonwords in a series of lexical decision tasks at two linguistic levels (concrete and abstract words). Analysis of variance on reaction times indicated that main effects of stimulus type, visual field, and the interaction of these variables were not significant for the reading-disordered group, but visual field and an interaction of visual field and stimulus type were for the normally reading adults. Error rate showed a significant interaction of stimulus x visual field for the reading-disordered group but not for the normal reading group. Post hoc tests showed significant differences in error rates between visual fields for concrete lexicon but not for abstract or nonsense lexicon for the reading-disordered group. These findings suggest a deficit in interhemispheric lexical transfer occurs for reading-disordered samples and suggest use of a callosal relay model wherein the left hemisphere is allocated responsibility for performing central operations underlying lexical decisions by adults with reading disorders.     

Effects of increasing expenditure of energy during exercise on psychological well-being in older adults

The purpose of present study was to examine the effects on psychological well-being of energy expended as a result of the exercise intervention. 33 older adults (M age=68.6 yr., SD=4.7) participated in three supervised water-based exercise sessions per week for 12 wk. Based on the relative changes in daily energy expenditure as measured by questionnaire between pre- and posttraining, the subjects were split into three groups. This classified each subject as either having experienced a relatively low change (n=11), moderate change (n= 11), or high change (n= 11) in daily energy expenditure. Our data showed that the group with the greater increase in energy expenditure as a result of exercise, when compared pre- and posttraining, improved only on Depression-Dejection on the Profile of Mood States more than did the group with low change. Consequently, we concluded that the amount of energy expended was partially related to improvement in psychological well-being.     

Memorization of young people under loud pink noise of short duration

Exposure of students to loud pink noise of short duration in schools with high background noise showed that memorization of the students under loud pink noise is correlated with noise level. For levels up to 91.5 dB(A) the performance of 275 students improved, but for louder noise performance was reduced.     

Implicit memory in schizotypal subjects and normal controls: effects of a secondary task on sequence learning

Using a serial reaction-time task, the implicit memory performances of 29 high scoring (schizotypes) and 24 low scoring subjects (controls) on the German version of the 1997 Schizotypal Personality Questionnaire by Klein, Andresen, and Jahn were compared. To test the hypothesis that schizotypes show a differential deficit, subjects participated either in a single task condition of the serial reaction-time task or in a dual task condition of a secondary tone-counting task. Neither under single task conditions nor under dual task conditions did schizotypes show any impairment of implicit memory compared with controls. In addition, a separate analysis of the response latencies for the unique and ambiguous transitions of the repeated sequence did not indicate any differences between the two groups. These findings support and augment the results reported by Ferraro and Okerlund (1995).     

Thermal sensitivity in Tourette syndrome: preliminary report

The effects of heat on tic symptoms were studied in a sample of 78 adults with Tourette syndrome. 62 men and 16 women completed a survey concerning the type, onset, and course of their tics. 10 adult male subjects also participated in a thermal challenge during which ambient temperature was raised from 22 degrees C to 35 degrees C following a control period. Of the 78, 24% or 19 reported increased tics upon exposure to heat. Compared to the remaining 59 subjects, there were no differences in sex distribution, current age, or overall course of illness. In the thermal challenge, there was general increase in tics that was correlated with sweat rate (r = .55, p = .001). This effect was prominent in 5 of 10 subjects (rs = .29 to .63). There were no mean differences in current age, age of onset, or current severity of symptoms between the five subjects of each group. Tic symptoms in a subgroup of patients with Tourette syndrome may be sensitive to heat. Abnormal heat regulation is not a likely explanation for the observed increase in tics. The increase may be due to normal heat-loss mechanisms through dopaminergic pathways.     

Methodology in subliminal psychodynamic activation: the next step in the debate

Subliminal psychdynamic activation methodology has recently been the subject of an exchange of views between Birgeg?rd and Sohlberg (1999) and Fudin (2000). The agreements and some remaining points of contention are summarized here. The main difference of opinion appears to concern unconscious verbal encoding in relation to subjective experience in subliminal stimulation and whether subliminal psychodynamic activation results are unreliable until a full explanation of how verbal encoding works is at hand. We conclude that clarifying perspectives is important and that those suggesting alternative explanations of results on subliminal psychodynamic activation must now empirically investigate their claims.     

The availability heuristic with famous names: a replication

In two experiments, 195 Canadian undergraduates initially judged a list of 25 names (12 famous men and 13 nonfamous women or 12 famous women and 13 nonfamous men) for familiarity. Contrary to previous research, subsequent estimates of the perceived number of men's and women's names were not higher when the names were famous than nonfamous. When the estimated differences were compared to the true difference (-1), famous names were judged more numerous than nonfamous names, but the size of the effect (d = 0.34) was smaller than in previous research. Reasons for these findings are discussed.     

A formal version of the Guided Search (GS2) model

Guided Search 2 (GS2) is currently one of the most detailed models of visual search and has been used to predict search times for different stimulus conditions by means of detailed computer simulations. The present article goes a step further and presents formulas that allow for the calculation of the search times and their variances. Moreover, these formulas can be applied to fit GS2 to data. An example is provided in which GS2 is fitted to search functions representing search asymmetries.     

Disorder in sequential speech perception: a case study on pure word deafness

We described disorders of a patient which were uniquely restricted to speech perception of syllable sequences after brain damage. The results of series of experiments using syllable sequences showed "negative recency effect," in which the subject's repetition performance at the latter syllable position was remarkably poor. Experimental analyses suggested that the "negative recency effect" could be due to dual factors: the lower rate of processing of speech sounds and the memory load of holding processes of preceding syllables imposed on the succeeding phonological processing. The results also suggested that the holding processes which imposed the memory load on the succeeding auditory phonological coding processing were modality nonspecific.     

Agrammatic Broca's aphasia is not associated with a single pattern of comprehension performance

One influential hypothesis posits that the brain regions implicated in Broca's aphasia are responsible for specific syntactic operations that are necessary for the comprehension and production of sentences (Grodzinsky, 1986, 1990, in press). The empirical basis of this hypothesis is the claim that Broca's aphasics have no difficulty understanding sentences in the active voice (and other "canonical" sentence types, such as subject relatives and clefts with negative predicates), but perform at chance level with passive voice constructions (and other "noncanonical" sentences such as object-gap relatives and object clefts). In the face of well-established results indicating that Broca's aphasics can exhibit several different performance patterns on these sentence types, Grodzinsky, Pi?ango, Zurif, and Drai (1999) argued that these conflicting results do not challenge the theory when the data are analyzed appropriately. They carried out a creative statistical analysis of the comprehension performance of published cases of Broca's aphasia and concluded that all of these cases are in agreement with the predicted pattern: chance on passives and 100% correct on actives. Here we show that the statistical reasoning adopted by Grodzinsky et al. (1999) is flawed. We also show that the comprehension performance of a substantial number of the Broca's aphasics in their own sample does not conform to the pattern required. Rather, contrary to these authors' claim, Broca's aphasia is not associated with a consistent pattern of sentence comprehension performance, but allows for a number of distinct patterns in different patients.