Podcast
Questions and Answers
How does grazing by bison affect the relationship between fire frequency and forb abundance in grasslands?
How does grazing by bison affect the relationship between fire frequency and forb abundance in grasslands?
- Grazing reverses the relationship, leading to a positive correlation between fire frequency and forb abundance. (correct)
- Grazing decreases fire frequency, leading to lower forb abundance.
- Grazing promotes C4 grass dominance, irrespective of fire frequency.
- Grazing has no impact on the relationship between fire frequency and forb abundance.
According to the research, how does frequent burning impact plant species diversity in tallgrass prairie?
According to the research, how does frequent burning impact plant species diversity in tallgrass prairie?
- Frequent burning dramatically increases C4 grass dominance, reducing plant species diversity. (correct)
- Frequent burning uniformly increases plant species diversity.
- Frequent burning decreases the dominance of C4 grasses, increasing diversity.
- Frequent burning has no significant impact on plant species diversity.
What role have herbivores, such as bison, historically played in tallgrass ecosystems?
What role have herbivores, such as bison, historically played in tallgrass ecosystems?
- They increased the competitive advantage of C4 grasses.
- They reduced habitat heterogeneity and decreased species diversity.
- They promoted habitat homogeneity.
- They served as keystone species by reducing C4 grass dominance and increasing habitat heterogeneity. (correct)
What is a consequence of anthropogenically driven global change in grassland ecosystems?
What is a consequence of anthropogenically driven global change in grassland ecosystems?
What does the research suggest about maintaining diversity in native vegetation historically affected by keystone herbivores?
What does the research suggest about maintaining diversity in native vegetation historically affected by keystone herbivores?
The anterior cingulate cortex (ACC) is thought to contribute to performance monitoring by:
The anterior cingulate cortex (ACC) is thought to contribute to performance monitoring by:
What is the primary alternate hypothesis about the function of the ACC based on the study?
What is the primary alternate hypothesis about the function of the ACC based on the study?
Regarding the Continuous Performance Test (AX-CPT), what was the primary modification made to increase error rates and manipulate response competition?
Regarding the Continuous Performance Test (AX-CPT), what was the primary modification made to increase error rates and manipulate response competition?
Besides the ACC, what other brain regions showed significant transient increases in activity associated with errors?
Besides the ACC, what other brain regions showed significant transient increases in activity associated with errors?
What does the study suggest regarding how error-related activity can occur in the ACC without a comparator process?
What does the study suggest regarding how error-related activity can occur in the ACC without a comparator process?
Flashcards
ACC Function: Competition Monitor
ACC Function: Competition Monitor
ACC monitors the competition between conflicting processes during task performance, predicting increased activity even in correct responses. ACC measures the response of the system.
Impact of Stimulus Degradation
Impact of Stimulus Degradation
Accuracy is higher with familiar stimuli and lower with unfamiliar or degraded stimuli. Stimulus degradation increases error rates.
Bison's Role in Ecosystems
Bison's Role in Ecosystems
Historically, bison served as keystone species by reducing C4 grass dominance, increasing habitat heterogeneity, and boosting species diversity.
Grazing Benefits
Grazing Benefits
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Burning Limitations
Burning Limitations
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Global Change Impact
Global Change Impact
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Grazing and Forb Abundance
Grazing and Forb Abundance
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Decline of Keystone Species
Decline of Keystone Species
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Study Notes
Anterior Cingulate Cortex (ACC) and Performance Monitoring
- The study investigates how the brain monitors performance to regulate behavior, focusing on the role of the anterior cingulate cortex (ACC).
- ACC is located on the medial surface of the frontal lobe.
- Prior hypothesis suggests the ACC contributes to performance monitoring by detecting errors.
- Current research confirms that ACC activity increases during erroneous responses using event-related functional magnetic resonance imaging.
- ACC activity also showed during correct responses if there was increased response competition, implying ACC detects potential error conditions rather than just errors.
- The study presents an alternative view that the ACC monitors competition between conflicting processes during task performance.
- Response competition arises when a task triggers a strong, but inappropriate response, needing to be overcome for accuracy. Conditions with response competition are more susceptible to errors
Methodology - AX-CPT Task
- Thirteen participants underwent fMRI while performing variants of the Continuous Performance Test (AX-CPT).
- Includes stimulus degradation to increase errors and manipulate response competition.
Findings and Interpretations
- Transient increase in ACC activity observed in error responses
- Greater ACC activity also seen in correct responses under conditions eliciting greater response competition.
- The ACC may be more involved in detecting response competition than detecting errors.
- Sensitivity to response competition can produce error-related effects, as trials with activity in the incorrect response channel compete with the correct response channel.
- The ACC contribution to performance monitoring involves detecting response competition.
Additional analyses
- Error and competition effects were examined in other ROIs.
- ROIs included two right inferior frontal regions and a right striatal region, previously shown to be activated by stimulus degradation.
- Error-related activity was observed in one right frontal region (BA 44/45), but no competition effects were observed in any ROI.
- In exploratory analysis of all brain regions scanned, 3 regions in addition to ACC showed transient activity increases associated with errors.
- The three regions were right (BA 9) and left (BA 46/9) dorsolateral prefrontal cortex and the left premotor cortex (BA 6).
- These regions did not show response competition effects
- The reconceptualization of ACC activity as related to response competition links its role in higher-level cognition with ERP.
- This hypothesis is more computationally efficient, requiring only information about the state of the response system rather than intended states and outcomes.
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