Where does vigilance collide?

In cognitive psychology, vigilance is the capacity to sustain attention on a monotonous task in order to detect infrequent, unpredictable signals, and its hallmark is the vigilance decrement: detection falls off within the first half hour on watch. Mackworth's 1948 The breakdown of vigilance during prolonged visual search, using a simulated-radar 'clock test', first measured this decline experimentally. The referent is a within-person attentional state that erodes over time on watch, measured by hit rate and reaction time, a different construct from the time-budgeting behaviour that behavioural ecologists call vigilance.[1]

Unit

Detection performance for rare signals sustained over time on task

Recovery means

Vigilance partially recovers with rest breaks and greater task variety

Measured by

Measured by the decline in hit rate and the rise in reaction time over a watch

In behavioural ecology, vigilance is the time an animal spends scanning its surroundings for predators instead of feeding, and a central result is that individuals in larger groups can each scan less while the group as a whole still detects threats sooner. Pulliam's 1973 On the advantages of flocking modelled this 'many eyes' effect, showing how group size lowers each member's required vigilance. The referent is an allocation of behaviour (a feeding-versus-scanning tradeoff shaped by predation risk and group size), measured by scan rate, and it is a distinct construct from the human attentional decrement that shares the word.[2]

Unit

The share of time an animal spends scanning rather than feeding

Recovery means

Not applicable

Measured by

Measured by scan frequency and duration as functions of group size and predation risk