Relating the mechanisms of orienting and alerting. Academic Article uri icon

Overview

abstract

  • Cues provide two types of information: information about where the target will occur and when it will occur. We hypothesized two underlying processes related to cues, orienting (to location) and alerting. Using a covert orienting task under different conditions of alertness, we found evidence of independence between orienting and alerting (Experiments 3-4). The alerting mechanism is spatially broad and seems common for auditory and visual input (Experiments 1-2). In Experiment 1, visual cues at four locations occur simultaneously to prevent orienting; response facilitation was the same for targets occurring near or far from a cue. In Experiment 2, adding a visual alerting signal to an auditory signal provided no additional benefit. In Experiment 3, an auditory signal was used to modulate the alertness level during a covert orienting task. Orienting, measured by the validity effect, was independent of the level of alertness in this simple reaction task. Experiment 4 extended those results to a choice task. These studies indicate separate mechanisms of alerting and orienting. The global mode of alertness is consistent with the broad axonal distribution of the noradrenergic system. In contrast, human and animal data suggest that the orienting mechanism may be modulated by the basal forebrain cholinergic system.

publication date

  • April 1, 1997

Research

keywords

  • Attention
  • Cues
  • Orientation

Identity

Scopus Document Identifier

  • 0030902683

Digital Object Identifier (DOI)

  • 10.1016/s0028-3932(96)00103-0

PubMed ID

  • 9106276

Additional Document Info

volume

  • 35

issue

  • 4