The article discusses the relationship between attention and the detection of signals, focusing on how attention influences the efficiency of detecting visual signals. Detection of a visual signal requires information to reach a system capable of eliciting arbitrary responses. Detection latencies are reduced when subjects receive a cue indicating where the signal will occur, as this shifts the efficiency of the central attentional system to the pathways activated by the visual input. The results suggest that the improvement in detection is not due to a reduced criterion at the expected target position, but rather to a centrally controlled attentional system. This system cannot be freely allocated but can only be directed over contiguous portions of the visual field. The attentional system appears not to be closely coupled to the saccadic eye movement system, and the retina is equipotential with respect to attention shifts, as costs to unexpected stimuli are similar whether foveal or peripheral. The article also discusses the role of attention in signal detection, distinguishing between detection and orienting. Detection involves the entry of information about the presence of a signal into a system that allows the subject to report the existence of the signal. Orienting involves aligning sensory or central systems with the input channel over which the signal occurs. The article argues that subjects may orient toward a signal without first detecting it. The results of experiments show that knowledge of the location of a signal affects processing efficiency. When a signal occurs at a position where the subject is prepared, electrical activity is enhanced in the first 100 msec following input. This suggests that knowledge of the location of a signal can improve detection. However, the results also show that the improvement is not due to a general tendency for any kind of information to improve performance, but rather to a centrally controlled attentional system. The article also discusses the limitations of the classical psychophysical approach to detection, which focuses on stimulus factors such as intensity, duration, and wavelength. It argues that this approach does not clearly separate between attentional factors and sensory factors, and thus is incapable of providing an analysis of the relationship between the two. The article also discusses the use of signal detection theory, which has greatly influenced studies of detecting stimuli. It distinguishes between the mathematical theory and its psychological application. The mathematical theory of signal detection is a powerful tool for the analysis of many problems, but it often produces in its users some implicit assumptions. The article also discusses the use of detection in various tasks, from separating a pure tone in white noise to the task of a radiologist locating a tumor. It argues that the same processes are not involved in these situations, as often, in addition to detecting the presence of a stimulus, a person must identify it in order to discriminate it from complex backgrounds. The article concludes that the results of the experiments suggest that attention is involved in signal detection, and that the attentional system is a separate system that interacts with the visual system. The findings suggest that attention is not closely coupled to the structure of the saccadic eye movementThe article discusses the relationship between attention and the detection of signals, focusing on how attention influences the efficiency of detecting visual signals. Detection of a visual signal requires information to reach a system capable of eliciting arbitrary responses. Detection latencies are reduced when subjects receive a cue indicating where the signal will occur, as this shifts the efficiency of the central attentional system to the pathways activated by the visual input. The results suggest that the improvement in detection is not due to a reduced criterion at the expected target position, but rather to a centrally controlled attentional system. This system cannot be freely allocated but can only be directed over contiguous portions of the visual field. The attentional system appears not to be closely coupled to the saccadic eye movement system, and the retina is equipotential with respect to attention shifts, as costs to unexpected stimuli are similar whether foveal or peripheral. The article also discusses the role of attention in signal detection, distinguishing between detection and orienting. Detection involves the entry of information about the presence of a signal into a system that allows the subject to report the existence of the signal. Orienting involves aligning sensory or central systems with the input channel over which the signal occurs. The article argues that subjects may orient toward a signal without first detecting it. The results of experiments show that knowledge of the location of a signal affects processing efficiency. When a signal occurs at a position where the subject is prepared, electrical activity is enhanced in the first 100 msec following input. This suggests that knowledge of the location of a signal can improve detection. However, the results also show that the improvement is not due to a general tendency for any kind of information to improve performance, but rather to a centrally controlled attentional system. The article also discusses the limitations of the classical psychophysical approach to detection, which focuses on stimulus factors such as intensity, duration, and wavelength. It argues that this approach does not clearly separate between attentional factors and sensory factors, and thus is incapable of providing an analysis of the relationship between the two. The article also discusses the use of signal detection theory, which has greatly influenced studies of detecting stimuli. It distinguishes between the mathematical theory and its psychological application. The mathematical theory of signal detection is a powerful tool for the analysis of many problems, but it often produces in its users some implicit assumptions. The article also discusses the use of detection in various tasks, from separating a pure tone in white noise to the task of a radiologist locating a tumor. It argues that the same processes are not involved in these situations, as often, in addition to detecting the presence of a stimulus, a person must identify it in order to discriminate it from complex backgrounds. The article concludes that the results of the experiments suggest that attention is involved in signal detection, and that the attentional system is a separate system that interacts with the visual system. The findings suggest that attention is not closely coupled to the structure of the saccadic eye movement