Neural basis for sentence comprehension deficits in frontotemporal dementia

Many patients with frontotemporal dementia (FTD) have impaired sentence comprehension. However, the pattern of comprehension difficulty appears to vary depending on the clinical subgroup. The purpose of this study was to elucidate the neural basis for these deficits in FTD. We studied patients with two different presentations: Three patients with Progressive Non-Fluent Ahasia (PNFA), and five non-aphasic patients with a dysexecutive and social impairment (EXEC). The FTD patient subgroups were compared to a cohort of 11 healthy seniors with intact sentence comprehension. We monitored regional cerebral activity with blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) while subjects read sentences featuring both a grammatically complex object-relative center-embedded clause and a long linkage between the head noun phrase (NP) and the gap where the NP is interpreted in the center-embedded clause. Subjects decided whether the agent of the action is a male or a female. Healthy seniors activated both ventral portions of inferior frontal cortex (vIFC) and dorsal portions of IFC (dIFC) in the left hemisphere, often associated with grammatical and working memory components of these sentences, respectively. PNFA patients differed from healthy controls since they have reduced activation of left vIFC, while EXEC patients have less recruitment of left dIFC. We conclude that FTD subgroups have distinct patterns of sentence comprehension difficulty in part because of selective interruptions of a large-scale neural network for sentence processing.     

Delayed symbolic matching in honeybees (Apis mellifera)

In a recent experiment on short-term memory (P. A. Couvillon, T. P. Ferreira, & M. E. Bitterman, 2003), honeybees (Apis mellifera) learned to choose between 2 colors on the basis of immediately preceding experience with 1 of them. Some learned to choose the same color as the sample (perseveration or matching), others to choose the alternative color (alternation or nonmatching). Performance in the 2 problems was very much the same. In the present experiment, honeybees learned no less readily to choose between the 2 colors on the basis of sample stimuli that were different from the colors (symbolic matching). A simple associative interpretation of the results is proposed.     

Movement related EMGs become more variable during learning of fast accurate movements

Human subjects performed simple flexion and extension movements about the elbow in a visual step-tracking paradigm. Movements were self-terminated. Subjects were instructed to increase movement velocity while maintaining end-point accuracy during practice. The effects of practice on the pattern and variability of EMG activity of the biceps and triceps muscles were studied. Initial movements were performed using reciprocal phasic activation of agonist and antagonist muscles as indicated by surface EMGs. With practice, increases in movement speed were associated with larger agonist and antagonist bursts and an earlier onset of the antagonist burst. Decreased duration of the premovement antagonist silence was also observed during practice. Decreases in variability of movements during practice were not accompanied by equivalent decreases in variability of the associated EMGs. Surprisingly, both agonist and antagonist EMGs were more variable in faster, practiced movements. The combined agonist-antagonist EMG variability depended on both movement speed and trajectory variability. Lower variability in movements in the presence of greater variability in the related EMGs occurred because of linked variations in agonist and antagonist muscle activities. Variations in the first agonist burst were often compensated for by associated variations in the antagonist and late agonist bursts. These linked variations maintained the limb trajectory relatively constant in spite of large variations in the first agonist burst. Modifications to impulse-variability models are therefore needed to explain compensations for variability in accelerative impulses (produced by the first agonist burst) by linked variations in impulses for deceleration (produced by the antagonist and late agonist bursts).     

Too much of a good thing? Examining the relationship between passion for exercise and exercise dependence

ObjectivesTo examine the relationship between passion (i.e., love for an activity that is valued for which and a great deal of time is invested) for exercise and exercise dependence symptoms.DesignA cross-sectional correlational survey design was utilised.MethodA total of 480 participants (n = 275 females, n = 205 males; M_age = 18.58, SD = 1.66) completed the Leisure Time Exercise Questionnaire (Godin, Jobin, & Bouillon, 1986), the Passion Scale (Vallerand et al., 2003), and the Exercise Dependence Scale-Revised (Hausenblas, Symons-Downs, & Nigg, 2004). Path analysis using structural equation modelling was used to assess the relationships between passion and exercise dependence.ResultsPath analysis using structural equation modelling via AMOS 20.0 (Arbuckle, 2011) revealed that harmonious passion (i.e., being in control of the activity and deciding when and when not to engage in it) was positively related to the exercise dependence dimensions of time and tolerance. On the other hand, obsessive passion (i.e., an internal compulsion to engage in the activity even when not appropriate to do so) was positively related to all seven exercise dependence dimensions: time, tolerance, withdrawal, continuance, intention effects, lack of control, and reduction in other activities (CFI = .91, RMSEA = .05, SRMR = .06).ConclusionAn empirical relationship has been established to support the proposed theoretical link between passion (harmonious and obsessive) for exercise and exercise dependence dimensions.     

Sort-Score Correlates of Schizophrenia

The Structured Objective Rorschach Test was administered to 61 schizophrenic patients in a psychiatric hospital. Ss scored within the average range on all but 2 of 27 attributes; these were the attributes Popular and Original. Popular and Original scores were inversely related and differentially related to W, Dd, and F-. When P and O were combined the score for the Conformity attribute was within the average range. A validity scale is discussed.     

Empathic understanding: Benefits of perspective-taking and facial mimicry instructions are mediated by self-other overlap

The current study sought to better understand the utility of two strategies—perspective-taking and facial mimicry—proposed to increase empathic responding. Thirty-seven female participants were presented an interpersonal situation (a betrayal) that would elicit the use of empathic responding to achieve conflict resolution between friends. Each participant was given instructions to partake in either perspective-taking, facial mimicry, or to remain neutral (control condition). The results demonstrated that individuals who engaged in perspective-taking reported significantly higher state empathy than the control condition, but there was no significant difference in state empathy between the mimicry and control condition. Also, those who engaged in either strategy reported significantly higher self-other overlap relative to those not instructed to engage in a particular strategy. Importantly, self-other overlap mediated the association between the instructional sets and state empathy. Both strategies are arguably means of enhancing interpersonal understanding.     

The role of context and timeframe in moderating relationships within the theory of planned behaviour

This study examined the moderating effect of context and timeframe on the predictive ability of Theory of Planned Behaviour (TPB) constructs. Three hundred and eighty-three students completed TPB measures either in a campus bar or a library and were randomly allocated to one of three timeframe conditions: tonight, tomorrow or next week. There was a three-way interaction such that the subjective norms of participants in a bar were more predictive of their intentions to binge drink that night, whereas the subjective norms of participants in a library were less predictive of intentions to binge drink that night. This research provides empirical evidence that ignoring context may result in underestimation of the importance of normative factors in binge drinking. It also suggests that other research utilising the TPB needs to take greater account of the impact of context of data collection, which has been neglected to date.