Affective pictures drive the activity of brain networks and impact behavior. We showed previously that viewing unpleasant
pictures interfered in the performance of a basic nonemotional visual detection task. In the present study, we employed functional
magnetic resonance imaging to test the hypothesis that behavioral interference may result from the interaction between negatively
valenced and motor-related signals in the brain. As in our previous study (Pereira et al., 2006), participants performed a
simple target detection task that followed the presentation of unpleasant or neutral pictures. Our results revealed that an
unpleasant emotional context modulated evoked responses in several regions engaged by the simple target detection task. In
particular, the midcingulate cortex was recruited when participants performed target detection trials during the unpleasant
context, and signal responses in this region closely mirrored the pattern of behavioral interference (as revealed via reaction
time). Our findings suggest that the midcingulate cortex may be an important site for the interaction between negatively valenced
signals and motor signals in the brain and that it may be involved in the implementation of defensive responses, such as freezing. 相似文献
This study aims to build a structural model to explore the predictors of adjustment to aging (AtA) reported by older women in breast cancer remission. A community-dwelling sample of 771 older women in breast cancer remission aged between 75 and 98 years answered a questionnaire to determine socio-demographic (age, income, marital status, education, household, and living setting), and health-related characteristics (self-reported functional limitations and disabilities, time since remission, other type of cancer, breast reconstruction, perceived health, recent disease and medication). Several measures were employed to assess AtA, sense of coherence and subjective well-being. Structural equation modeling was used to explore a structural model of the self-reported AtA, encompassing all variables. Significant predictors of AtA are self-reported disability (β = .404; p < .001), time since remission (β = .371; p < .001), perceived health (β = .257; p < .001), other type of cancer (β = .231; p < .001), breast reconstruction (β = .153; p = .008), marital status (β = .141; p < .001), sense of coherence (β = .140; p < .001), and living setting (β = .139; p = .006). These variables accounted for 84.3% of the variability of AtA. Self-reported disability and time since remission were the strongest predictors of AtA. Our findings suggest that health care interventions with older women in breast cancer remission still living in the community may benefit from clearly including these predictors of AtA, as they are relevant for promoting older women’ s aging well.
We examined the effects of cognitive load on the strategy selection in the forced choice test (FCT) when used to detect hidden crime knowledge. Examinees (N = 120) with and without concealed knowledge from a mock crime were subjected to an FCT either under standard circumstances or cognitive load. Cognitive load was implemented through time pressure. The FCT distinguished examinees with concealed knowledge from those without better than chance in both conditions, but the counterstrategies did not differ between conditions. Further investigation revealed that time pressure did affect examinees' ability to follow their intended counterstrategy to produce randomized test patterns, which constitutes an effective counterstrategy in the FCT. Hence, time pressure lowered the success rate of effective counterstrategies, but not their incident rates. Further disambiguation of various cognitive load manipulations and their effects on strategy selection and execution is needed. 相似文献
This study aimed to evaluate the relationship between posturography, clinical balance, and executive function tests in Parkinson´s disease (PD). Seventy-one people participated in the study. Static posturography evaluated the center of pressure fluctuations in quiet standing and dynamic posturography assessed sit-to-stand, tandem walk, and step over an obstacle. Functional balance was evaluated by Berg Balance Scale, MiniBESTest, and Timed Up and Go test. Executive function was assessed by Trail Making Test (TMT) and semantic verbal fluency test. Step over obstacle measures (percentage of body weight transfer and movement time) were moderately correlated to Timed Up and Go, part B of TMT and semantic verbal fluency (r > 0.40; p < 0.05 in all relationships). Stepping over an obstacle assesses the responses to internal perturbations. Participants with shorter movement times and higher percentage of body weight transfer (higher lift up index) on this task were also faster in Timed Up and Go, part B of TMT, and semantic verbal fluency. All these tasks require executive function (problem solving, sequencing, shifting attention), which is affected by PD and contribute to postural assessment. 相似文献
A persistent criticism of radical embodied cognitive science is that it will be impossible to explain “real cognition” without invoking mental representations. This paper provides an account of explicit, real-time thinking of the kind we engage in when we imagine counter-factual situations, remember the past, and plan for the future. We first present a very general non-representational account of explicit thinking, based on pragmatist philosophy of science. We then present a more detailed instantiation of this general account drawing on nonlinear dynamics and ecological psychology.
To test the assumptions of two models of timing, Scalar Expectancy Theory (SET) and Learning to Time (LeT), nine pigeons were exposed to two temporal discriminations, each signaled by a different cue. On half of the trials, pigeons learned to choose a red key after a 1.5-s horizontal bar and a green key after a 6-s horizontal bar; on the other half of the trials, they learned to choose a blue key after a 6-s vertical bar and a yellow key after a 24-s vertical bar. During subsequent test trials, they were exposed to the horizontal or vertical bar, for durations ranging from 1.5 to 24 s, and given a choice between novel key combinations: red vs. yellow, or green vs. blue. Results showed a strong effect of sample duration—as the test signal duration increased, preference for green over blue increased and preference for red over yellow decreased. The effect of sample cue was obtained only on the green-blue test trials. These effects are discussed in light of SET and LeT. 相似文献
To meet an increasing need to examine the neurophysiological underpinnings of behavior in rats, we developed a behavioral system for studying sensory processing, attention and discrimination learning in rats while recording firing patterns of neurons in one or more brain areas of interest. Because neuronal activity is sensitive to variations in behavior which may confound the identification of neural correlates, a specific aim of the study was to allow rats to sample sensory stimuli under conditions of strong behavioral regularity. Our behavioral system allows multimodal stimulus presentation and is coupled to modules for delivering reinforcement, simultaneous monitoring of behavior and recording of ensembles of well isolated single neurons. Using training protocols for simple and compound discrimination, we validated the behavioral system with a group of 4 rats. Within these tasks, a majority of medial prefrontal neurons showed significant firing‐rate changes correlated to one or more trial events that could not be explained from significant variation in head position. Thus, ensemble recordings can be combined with discriminative learning tasks under conditions of strong behavioral regularity. 相似文献
Deletions, translocations, or point mutations in the CREB-binding protein (CBP) gene have been associated with Rubinstein-Taybi Syndrome; a human developmental disorder characterized by retarded growth and reduced mental function. To examine the role of CBP in memory, transgenic mice were generated in which the CaMKII alpha promoter drives expression of an inhibitory truncated CBP protein in forebrain neurons. Examination of hippocampal long-term potentiation (LTP), a form of synaptic plasticity thought to underlie memory storage, revealed significantly reduced late-phase LTP induced by dopamine-regulated potentiation in hippocampal slices from CBP transgenic mice. However, four-train induced late-phase LTP is normal. Behaviorally, CBP transgenic mice exhibited memory deficits in spatial learning in the Morris water maze and deficits in long-term memory for contextual fear conditioning, two hippocampus-dependent tasks. Together, these results demonstrate that CBP is involved in specific forms of hippocampal synaptic plasticity and hippocampus-dependent long-term memory formation. 相似文献