at the importance of tasks. as an alternative, resource theory has been proposed as a more accurate metaphor for explaining divided attention on complex tasks. resource theory states that as each complex task is automatized, performing that task requires less of the individual's limited-capacity attentional resources. other variables play a part in our ability to pay attention to and concentrate on many tasks at once. these include, but are not limited to, anxiety, arousal, task difficulty, and skills. simultaneous simultaneous attention is a type of attention, classified by attending to multiple events at the same time. simultaneous attention is demonstrated by children in indigenous communities, who learn through this type of attention to their surroundings. simultaneous attention is present in the ways in which children of indigenous backgrounds interact both with their surroundings and with other individuals. simultaneous attention requires focus on multiple simultaneous activities or occurrences. this differs from multitasking, which is characterized by alternating attention and focus between multiple activities, or halting one activity before switching to the next. simultaneous attention involves uninterrupted attention to several activities occurring at the same time. another cultural practice that may relate to simultaneous attention strategies is coordination within a group. indigenous heritage toddlers and caregivers in san pedro were observed to frequently coordinate their activities with other members of a group in ways parallel to a model of simultaneous attention, whereas middle-class european-descent families in the u.s. would move back and forth between events. research concludes that children with close ties to indigenous american roots have a high tendency to be especially wide, keen observers. this points to a strong cultural difference in attention management. alternative topics and discussions overt and covert orienting attention may be differentiated into "overt" versus "covert" orienting. overt orienting is the act of selectively attending to an item or location over others by moving the eyes to point in that direction. overt orienting can be directly observed in the form of eye movements. although overt eye movements are quite common, there is a distinction that can be made between two types of eye movements; reflexive and controlled. reflexive movements are commanded by the superior colliculus of the midbrain. these movements are fast and are activated by the sudden appearance of stimuli. in contrast, controlled eye movements are commanded by areas in the frontal lobe. these movements are slow and voluntary. covert orienting is the act of mentally shifting one's focus without moving one's eyes. simply, it is changes in attention that are not attributable to overt eye movements. covert orienting has the potential to affect the output of perceptual processes by governing attention to particular items or locations (for example, the activity of a v4 neuron whose receptive field lies on an attended stimuli will be enhanced by covert attention) but does not influence the information that is processed by the senses. researchers often use "filtering" tasks to study the role of covert attention of selecting information. these tasks often require participants to observe a number of stimuli, but attend to only one. the current view is that visual covert attention is a mechanism for quickly scanning the field of view for interesting locations. this shift in covert attention is linked to eye movement circuitry that sets up a slower saccade to that location. there are studies that suggest the mechanisms of overt and covert orienting may not be controlled separately and independently as previously believed. central mechanisms that may control covert orienting, such as the parietal lobe, also receive input from subcortical centres involved in overt orienting. in support of this, general theories of attention actively assume bottom-up (reflexive) processes and top-down (voluntary) processes converge on a common neural architecture, in that they control both covert and overt attentional systems. for example, if individuals attend to the right hand corner field of view, movement of the eyes in that direction may have to be actively suppressed. exogenous and endogenous orienting orienting attention is vital and can be controlled through external (exogenous) or internal (endogenous) processes. however, comparing these two processes is challenging because external signals do not operate completely exogenously, but will only summon attention and eye movements if they are important to the subject. exogenous (from greek exo, meaning "outside", and genein, meaning "to produce") orienting is frequently described as being under control of a stimulus. exogenous orienting is considered to be reflexive and automatic and is caused by a sudden change in the periphery. this often results in a reflexive saccade. since exogenous cues are typically presented in the periphery, they are referred to as peripheral cues. exogenous orienting can even be observed when individuals are aware that the cue will not relay reliable, accurate information about where a target is going to occur. this means that the mere presence of an exogenous cue will affect the response to other stimuli that are subsequently presented in the cue's previous location. several studies have investigated the influence of valid and invalid cues. they concluded that valid peripheral cues benefit performance, for instance when the peripheral cues are brief flashes at the relevant location before the onset of a visual stimulus. posner and cohen (1984) noted a reversal of this benefit takes place when the interval between the onset of the cue and the onset of the target is longer than about 300 ms. the phenomenon of valid cues producing longer reaction times than invalid cues is called inhibition of return. endogenous (from greek endo, meaning "within" or "internally") orienting is the intentional allocation of attentional resources to a predetermined location or space. simply stated, endogenous orienting occurs when attention is oriented according to an observer's goals or desires, allowing the focus of attention to be manipulated by the demands of a task. in order to have an effect, endogenous cues must be processed by the observer and acted upon purposefully. these cues are frequently referred to as central cues. this is because they are typically presented at the center of a display, where an observer's eyes are likely to be fixated. central cues, such as an arrow or digit presented at fixation, tell observers to attend to a specific location. when examining differences between exogenous and endogenous orienting, some researchers suggest that there are four differences between the two kinds of cues: exogenous orienting is less affected by cognitive load than endogenous orienting; observers are able to ignore endogenous cues but not exogenous cues; exogenous cues have bigger effects than endogenous cues; and expectancies about cue validity and predictive value affects endogenous orienting more than exogenous orienting. there exist both overlaps and differences in the areas of the brain that are responsible for endogenous and exogenous orientating. another approach to this discussion has been covered under the topic heading of "bottom-up" versus "top-down" orientations to attention. researchers of this school have described two different aspects of how the mind focuses attention to items present in the environment. the first aspect is called bottom-up processing, also known as stimulus-driven attention or exogenous attention. these describe attentional processing which is driven by the properties of the objects themselves. some processes, such as motion or a sudden loud noise, can attract our attention in a pre-conscious, or non-volitional way. we attend to them whether we want to or not. these aspects of attention are thought to involve parietal and temporal cortices, as well as the brainstem. more recent experimental evidence support the idea that the primary visual cortex creates a bottom-up saliency map, which is received by the superior colliculus in the midbrain area to guide attention or gaze shifts. the second aspect is called top-down processing, also known as goal-driven, endogenous attention, attentional control or executive attention. this aspect of our attentional orienting is under the control of the person who is attending. it is mediated primarily by the frontal cortex and basal ganglia as one of the executive functions. research has shown that it is related to other aspects of the executive functions, such as working memory, and conflict resolution and inhibition. influence of processing load a "hugely influential" theory regarding selective attention is the perceptual load theory, which states that there are two mechanisms that affect attention: cognitive and perceptual. the perceptual considers the subject's ability to perceive or ignore stimuli, both task-related and non task-related. studies show that if there are many stimuli present (especially if they are task-related), it is much easier to ignore the non-task related stimuli, but if there are few stimuli the mind will perceive the irrelevant stimuli as well as the relevant. the cognitive refers to the actual processing of the stimuli. studies regarding this showed that the ability to process stimuli decreased with age, meaning that younger people were able to perceive more stimuli and fully process them, but were likely to process both relevant and irrelevant information, while older people could process fewer stimuli, but usually processed only relevant information. some people can process multiple stimuli, e.g. trained morse code operators have been able to copy 100% of a message while carrying on a meaningful conversation. this relies on the reflexive response due to "overlearning" the skill of morse code reception/detection/transcription so that it is an autonomous function requiring no specific attention to perform. this overtraining of the brain comes as the "practice of a skill 100% accuracy," allowing the activity to become autonomic, while your mind has room to process other actions simultaneously. based on the primary role of the perceptual load theory, assumptions regarding its functionality surrounding that attentional resources are that of limited capacity which signify the need for all of the attentional resources to be used. this performance, however, is halted when put hand in hand with accuracy and reaction time (rt). this limitation arises through the measurement of literature when obtaining outcomes for scores. this affects both cognitive and perceptual attention because there is a lack of measurement surrounding distributions of temporal and spatial attention. only a concentrated amount of attention on how effective one is completing the task and how long they take is being analyzed making a more redundant analysis on overall cognition of being able to process multiple stimuli through perception. clinical model attention is best described as the sustained focus of cognitive resources on information while filtering or ignoring extraneous information. attention is a very basic function that often is a precursor to all other neurological/cognitive functions. as is frequently the case, clinical models of attention differ from investigation models. one of the most used models for the evaluation of attention in patients with very different neurologic pathologies is the model of sohlberg and mateer. this hierarchic model is based in the recovering of attention processes of brain damage patients after coma. five different kinds of activities of growing difficulty are described in the model; connecting with the activities those patients could do as their recovering process advanced. focused attention: the ability to respond discretely to specific sensory stimuli. sustained attention (vigilance and concentration): the ability to maintain a consistent behavioral response during continuous and repetitive activity. selective attention: the ability to maintain a behavioral or cognitive set in the face of distracting or competing stimuli. therefore, it incorporates the notion of "freedom from distractibility." alternating attention: the ability of mental flexibility that allows individuals to shift their focus of attention and move between tasks having different cognitive requirements. divided attention: this refers to the ability to respond simultaneously to multiple tasks or multiple task demands. this model has been shown to be very useful in evaluating attention in very different pathologies, correlates strongly with daily difficulties and is especially helpful in designing stimulation programs such as attention process training, a rehabilitation program for neurological patients of the same authors. other descriptors for types of attention mindfulness: mindfulness has been conceptualized as a clinical model of attention. mindfulness practices are clinical interventions that emphasize training attention functions. vigilant attention: remaining focused on a non-arousing stimulus or uninteresting task for a sustained period is far more difficult than attending to arousing stimuli and interesting tasks, and requires a specific type of attention called 'vigilant attention'. thereby, vigilant attention is the ability to give sustained attention to a stimulus or task that might ordinarily be insufficiently engaging to prevent our attention being distracted by other stimuli or