Please enable JavaScript.
Coggle requires JavaScript to display documents.
SDT & Vigilance (Brain regions (Basal forebrain cholinergic system…
SDT & Vigilance
Brain regions
Basal forebrain cholinergic system & LC: blocking the release of ACh in the forebrain with GABA impairs vigilance performance
Inferior Frontal Junction: setting up S-R connections, rule representation, in tasks with overt responses, in discrimination tasks, with temporally fixed event occurence (ooposite of midlateralPFC)
-
Midlateral PFC: selective biasing & filtering, monitoring the input-induced activation level of task schema, continuous monitoring of relevant external events, in tasks with covert responses, in simple detection, in tasks with a variable temporal structure of event occurence
-
Dorsomedial PFC/ Midcingulate Cortex (monitors performance & energetical state, reengagement in task-relevant processing, outcome monitoring), Anterior Insula (need for effort signaling)
- pre SMA: control of motor output eg. motor preparation, facilitation, inhibition
-
Temporoparietal Junction: when task-relevant changes in environment are detected, when expectations about stimuli are violated, need for reorientation signalling
-
Intraparietal Sulcus: selectivity, attentional priority signaling, in discrimination tasks, with fixed temporal structures
-
SDT & Vigilance relation
decline in Hits with stable or increasing rate of FAs -> reduction in discriminatory power of perceptual system
-
-
in vigilance situations, it is difficult to discriminate signals from noise -> overlap between N & N+S distributions
detection efficiency in vigilance situations assessed by the nr. of hits & FAs & by target detection tendencies
response latencies in vigilance situations can be accommodated within SDT:
- latencies associated with Hits & FAs increased wit time at work (affirmative responses)
- latencies associated with Misses & CR either decreased or remained stable (negatve responses)
typical reduction in detection efficiency in vigilance is associated with a progressively more stringent response criterion -> Beta increases with time on task (conservative)
- it could be either criterion increment or sensitivity decrement
SDT Basics
-
combining Hits & FAs data to indicate: response criterion placement + perceptual sensitivity -> sensory & decision processes
the greater the overlap between the two distributions, the lower the d (observer's sensitivity) -> more difficult to discriminate N from N+S
-
Receiver Operating Characteristic: illustrates perceiver's responses for many strategies (more bowed curve -> better sensitivity)
Assumptions:
- Internal noise has a specific distribution across trials
- Same noise distribution for N trials & S+N trials
- Signal & noise add up linearly ie. don't interact
- Decision is based on two consecutive processing stages (sensory stage/internal response + Decision stage/decision criterion)
-
-
Theories
Filter Theory (Broadbent)
- attending to the same information for long periods of time is prone to intermittent interruptions that tend to increase with time on tasks (filter is biased towards the selection of novel information)
- support: vigilance tasks in which signals are presented for only a brief period will yield bigger decrement
- increasing event presentation rate enhances the decrement because more events are presented within a given interval
-
Expectancy Theory:
- observers keep track of past signal occurrences to predict future ones-> formulation of expectancies, which can be assisted by task situation
- signal frequency is crucial
Inhibition & Habituation (not well supported)
- vigilance decrement as extinction of conditioned response when that response is no longer reinforced
- decline in detection rate = accumulation of inhibition (fatigue)
- support: knowledge of results & rest abolish the decrement (+)
CONS
- only concerns vigilance decrement & doesn't explain general low performance levels (-)
- increases in the frequency in which the signals are presented should increase the decline in detection efficiency (accelerate inhibition accumulation) but they actually reduce the decrement (-)
- Event rate manipulation doesn't have an effect & also no behavioral evidence (-)
Resource Theory (quite supported): perceptual sensitivity decrement seems to be controlled by overall task demands
- prolonged performance may deplete the pool of resources
Mackworth Clock Task
- large black pointer in a large circular background like a clock
- the pointer moves in short jumps, ca. every second
- at infrequent/irregular intervals, the hand makes a double jump
--> detect when the double jumps occur
-
At first, this might be easy & you would rarely lose track of the target. But with time, it becomes harder to maintain focus -> your mind drifts & attentional lapses become more frequent
-