Psyc201 Test 1, Labs Flashcards
What is Signal Detection Theory (SDT)?
A framework for understanding decision-making under uncertainty, involving the detection of a signal amidst noise.
What are the two types of errors in Signal Detection Theory?
False Alarm (diagnosing a condition when it isn’t present) and Miss (failing to diagnose a condition when it is present).
What is the difference between sensitivity and specificity in medical testing?
Sensitivity focuses on maximizing true identifications, while specificity focuses on minimizing false identifications.
What is discrimination in the context of SDT?
The ability to distinguish between the presence and absence of a signal, combining sensitivity and specificity.
What factors contribute to bias (criterion) in decision-making?
Personal factors, situational factors, and the trade-off between types of errors (misses vs. false alarms).
What is the role of V1 neurons in signal detection?
V1 neurons fire in response to specific stimuli, but can also fire without the stimulus or to a close neighbor, contributing to noise.
What does d’ (d prime) measure in SDT?
d’ measures discrimination, indicating how well hits can be distinguished from false alarms.
* d’ = 0 means no discrimination (hit rate = false alarm rate)
* d’ = 1 is considered to be evidence of discrimination
* Negative values of d’ means that people can distinguish, but they are always wrong.
What does c measure in SDT?
c measures bias (criterion), indicating whether people are more likely to say yes or no in situations of uncertainty.
What do positive and negative values of c indicate?
Positive values indicate a conservative criterion (bias to say no), while negative values indicate a liberal criterion (bias to say yes).
How does understanding our evolved detection systems help explain cognitive biases?
It provides insights into why we make certain types of errors and how our decision-making processes are influenced by biases.
What determines d’?
The nature of the input.
- Easier to distinguish a horizontal line from a vertical line than to distinguish a 30- degree line from a 60-degree line.
- Easier to distinguish a dachshund from a german shepherd than from a corgy.
The nature of the neural response.
- The more specific the neural response is to the signal, the less likely it is to be confused for noise.
- Neural responses can get better with practice (e.g., expertise in wine tasting, refereeing, detecting tumours)
What functions are primarily associated with the left hemisphere of the brain?
Language production, reading, and fine motor control.
What functions are primarily associated with the right hemisphere of the brain?
Attention, spatial processing, and face perception.
What happens when the corpus callosum is severed?
It separates the left and right cortex, often done to prevent the spread of seizures in severe epilepsy cases.
What is the visual half-field technique?
Presenting stimuli very briefly (<200ms) to prevent eye movement, used to study hemispheric specialization
What is the verbal dichotic listening task and what advantage does it show?
A task where different sounds are played in each ear, showing a right-ear advantage for language.- left ear shows advantage in emotional dichotic listening task
What are the concluding takeaways about hemispheric specialization?
Both hemispheres have specialized functions, but they contribute to most cognitive abilities, and some common beliefs about strict “left-brain” versus “right-brain” traits are myths.
