Early And Late Models Of Selective Attentional Processes

Attention describes focusing limited mental resources on cognitive processes that are most prominent at a given moment. Attention being such an intrinsic part of our day has therefore been studied to help understand how attention is both managed and governed (Eysenck & Keane, 2013). Understanding attention means to be aware of two attention processes; namely, as selective and divided attention. This essay will look at early and late models of selective attention, along with a discussion of experiments that have been put forward to help explain how we achieve these attentional processes. Furthermore, this will be contrasted with divided attention and the motivational control and executive processes that underpin this type of attention. Before one can critically evaluate attention, one needs to understand what attention is. Attention is comprised of different visual and auditory processes, because in each moment, there is different stimuli that require attentional focus. By living in an environment that has a large amount of sensory output; one needs to make sense of it (Eysenck & Keane, 2013). Sometimes, one needs to “filter” out erroneous stimuli in order to safely carry out tasks, and this is where selective attention comes into play (Harley, 2014). Selective attention in essence is the ability to focus attention on certain stimuli and process them under attentional control.

A pioneering model of selective attention belongs to Cherry who first identified the ‘cocktail party phenomenon’, which describes the ability to listen selectively to one conversation during a party while not paying attention to the noise surrounding an individual (Eysenck & Keane, 2013). Cherry demonstrated this using dichotic listening tasks where an experiment was designed to play out different messages are presented to each ear of a participant (Furnham, Davey & Field, 2012). Thereafter, the participant must repeat one message. This is to ascertain whether the individual is attending to the shadowed information. The Cocktail Party effect tried to make sense of how an individual can hear their partner’s conversation in a loud room and all other stimuli becomes background noise. This was a pioneering theory in the 1950’s and many theorists tried to understand how we processed information in such sensory overwhelming situations. One proponent to understand Cherry’s findings was Broadbent, as he developed a theory to help understand the Cocktail Party Effect (Furnham, Davey & Field, 2012). Broadbent argued that, to prevent us from becoming overwhelmed by sensory input, there is an attentional filter that prevents all but the desired, selected message from getting through to perceptual processing (Furnham, Davey & Field, 2012). It soon became clear that the model had its flaws, because an attentional filter does not offer enough explanation of how we can selectively attend to information in settings that offer a lot to process. A different researcher, Moray in 1959 developed another study to see if we could attend to messages outside of our “attentional filter” (Furnham, Davey & Field, 2012).

In his study, Moray found that individuals could recognize their own names in their unattended ear, a common phenomenon in a noisy room (Furnham, Davey & Field, 2012). Here, selective attention appears to be governed by processes more complex than dichotic listening, as individuals can selectively tune into a stimulus they were not even consciously aware was taking place. More extensive research needed to be done to understand exactly how we could pay attention to new information outside of our cognisance. Broadbent then went further to explain selective attention and its underpinnings. Broadbent later strengthened his theory to say that individuals attend to a particular physically definable channel of information (Eysenck & Keane, 2013). This means that any stimuli that fall outside our processing stream are not processed further than noticing the physical features thereof. This theory is notably as one of the most recognisable accounts of how we process our environment. This model served as an introduction into understanding selective attention; however, it lacks pertinence because the model focuses on a one dimentional understanding of selective attention. Seen as though there were inadequacies in Broadbent’s model, there had to be a conceptualization that understood more than just the physio-biology of attending to a message. In light of this, Treisman proposed a model that was deemed as more inclusive of other cognitive processes (Schwartzstein, 2014).

This was called Treisman’s attenuation model of selective attention. In this model, it was argued that all messages were processed beyond the sensory stage; however, any of the unattended stimuli became subject to attenuation (Furnham, Davey & Field, 2012). Here, Broadbent’s filter is replaced by an attenuator that ‘softens’ the unattended stimuli. In essence, the sensory volume of all input is turned down, so we can cope better with attending to various parts of the environment. The attenuation is important because attention is finite and can handle only a limited amount of sensory input at a time. A recent study by Müller-Plath and Klöckner (2014) highlights a key flaw with this model by stating that the use of the word “attenuator” is very vague. They asked a fundamental question: How can stimulus-driven attention be selective to features in a way that one feature is prioritized over another? Müller-Plath and Klöckner (2014) were also critical of the conceptualization of a stimulus being “softened”. Their study designed an experimental paradigm that challenged this vague view of attending to information.

They found in two experiments that concept such as “softening” and “attenuator” is too archaic to account for selective attention. In fact, after studying post-graduate students in an experiment controlling attentional signals, Müller-Plath and Klöckner (2014) found that there are more scientific ways of understanding selective attention. These researchers found two types of cues (onset cues and contingent cues) that decreased selective attention, while enhancing individual bias of what to respond to. Here, one can see Treisman, while pioneering understanding in attention, failed to account for bias, different cues and the underlying mechanics of selective attention (Furnham, Davey & Field, 2012). The common feature of these theories is that they propose an over-simplified understanding to what is processed.

These theories are known as early selection models. In contrast, late selection models, proposed by Deutsch and Deutsch and Norman argued that all inputs are processed perceptually and for meaning but with no attenuation (Furnham, Davey & Field, 2012). This is why individuals could recognize their own names and the identity of the two messages. While these individuals agree with the early bottleneck theory, they state that it is apparent at the response stage, when only one of the messages can be responded to. While Treisman stated that with multiple messages, one can selectively attend between two messages on the basis of their physical characteristics, Deutsch and Deutsch believed that these multiple messages of information are recognized but are quickly forgotten unless they hold personal pertinence to the individual (Furnham, Davey & Field, 2012). More modern studies seem to transcend the idea that selective attention is governed by auditory processing alone. In understanding visual cues in relation to selective attention, a key proponent is William James who coined the term the "spotlight" model work. Psychologist William James suggested that humans have a spotlight which entails a focal point in which things are viewed clearly (Herbranson, 2017).

The area surrounding this focal point, known as the fringe, is still visible, but not clearly seen and the area outside of this fringe is then known as a margin (Herbranson, 2017). This model suggests that there is a focal point where a large portion of finite resources are expended. There are just enough resources for any stimuli that catch attention in our peripheral vision, meaning our cognitive processes are available for life threatening, interesting or new stimuli in our environment (Herbranson, 2017). Akin to this is the "zoom-lens" model which suggests that we are able to increase or decrease the size of our focus much like the zoom lens of a camera. However, a larger focus area also results in slower-processing since it includes more information so the limited attentional resources must be distributed over a larger area. Like many metaphors, though, it’s not wise to take the attentional spotlight or the zoom-lens too literally. Subsequent findings examining the details have questioned several aspects of these theories, but there are two main objections to both: Studies suggest that attention can be split between two locations: this doesn’t easily fit with the idea of a single attentional ‘beam’ or ‘lens’. Research has shown that we can actually process visual stimuli outside the spotlight/zoom-lens quite thoroughly.

What happens to a visual stimulus not in the spotlight? Is it completely shut out, as in Broadbent’s auditory model? Is it attenuated, as in Treisman’s auditory model? Or is it fully processed, as in Deutsch and Deutsch’s auditory model? In taking all theories into account, an overarching theme is the finite aspect of attention as a whole. In present times, attention has been studied under the lens of a multiple resource model, where there are different attentional resources for sensory modalities, coding modes and response rates as well (Karlsson, Loewenstein, & Seppi, 2009). This model proposes that there are four important categorical dimensions that exist in any time-sharing performance. All other things being equal (i. e. equal resource demand or single task difficulty), two tasks that both demand one level of a given dimension (e. g. two tasks demanding visual perception) will interfere with each other more than two tasks that demand separate levels on the dimension (Karlsson, Loewenstein, & Seppi, 2009). This stage dichotomy can be supported by physiological evidence. Shallice in 1985 examined dual task performance on a series of tasks involving speech recognition (perception) and production (response) and concluded that the resources underlying these two processes are somewhat separate (Eysenck & Keane, 2013). Having this evidence to showcase attention as a finite resource makes understanding divided attention so crucial.

Divided attention occurs when there is a focus is on multiple tasks at the same time. Compared with selective attention, divided attention explains not just focusing solely on one stimulus, but rather doing several tasks at the same time. Examples are talking to a passenger while driving a car, texting a message on a device while walking, or listening to music while studying for an exam. Divided attention does decrease the amount of attention being placed on any one task if there are multiple focuses going on at once. Furthermore, it has been critically evaluated to understand if there are different processes in contrast to selective attention. Many theories of divided attention tend to focus on the idea of attention being a limited resource and how those resources are divvied up among competing sources of information. Such theories hypothesize that we have a fixed amount of attention available and that we must then choose how we allocate our available attentional reserves among multiple tasks or events. Several models arose in an attempt to understand divided attention. Kahneman’s model in 1973 model argues that attention is a limited resource but that it is, to some extent under strategic control (Eysenk & Keane, 2013).

Motivation and effort can affect the amount of available capacity, but only to an upper limit. Attentional capacity can similarly be increased to meet the demands of a difficult task or decreased to deal with an easier task, but the ability to perform two tasks simultaneously therefore depends on the demands the two tasks make on this central capacity (Seitz, Polack & Miller, 2018). If both tasks can be carried out without exceeding the capacity then they will be performed together as well as they will be performed separately. If the demands of the task exceed capacity then one or both tasks will suffer. While this certainly poses an interesting take on divided attention, research has shown this theory to have some inadequacies. For example, research conducted by Schwartzstein in 2016 studied how skill acquisition and practice could affect divided task activity outputs. The findings suggest that well-learned performance may actually be compromised by attending to skill execution such as attending to a gold swing (Schwartzstein, 2016).

Researchers have proposed that pressure to perform at a high level prompts attention to the step-by-step components of a well-learned skill. This attention is thought to disrupt or slow down skill execution, resulting in a less than optimal performance outcome. Therefore, Kahneman’s model fails to account for these cognitive processes. Assessing divided attention may be helpful in professional areas, where divided attention is important, because it appears to have more convoluted processes than selective attention. Understanding divided attention can also help in academic fields (if a student needs extra time taking notes or completing certain tasks), or clinical areas (maybe a patient needs more time to collect the proper information) (Shiffrin, Pisoni & Castaneda-Mendez, 2014). In all of these areas, understanding the executive processes that underpin these theories may directly help the user understand their day-to-day lives in a more in-depth context.

According to researchers Herbranson (2017), there are two stages to the executive control process of divided attention. The first stage is known as "goal shifting", which is where we choose one task or stimulus over the other. The second is known as "role activation" which means adjusting from the requirements of the previous task to the requirements of the new one (Herbranson, 2017). Switching between these may only add a time cost of just a few tenths of a second, but there is an additive effect if this switching constantly takes place. This is not problematic in tasks where low risk is present such as watching television. However, where efficiency and safety are paramount, even small time delays can become harmful. Task performance often deteriorates during dual tasks requiring divided attention in relation to single task conditions (herbranson, 2017). It is widely presumed that this dual task interference occurs when the component tasks require the same limited sensory, cognitive or cortical resources Out of the two attentional systems, what is interesting to note is that compared to selective attention, divided attention can often be more detrimental in the long term. In one 2009 study, it was found that individuals who multitasked often were less adept at sorting between relevant and irrelevant information (Quigley & Miller, 2014). The surprising feature here is that people would assume multitaskers would be better suited at this cognitive process.

In addition, multitaskers also showed greater difficulty when it came to switching from one task to another and were much less mentally organized (Quigley & Miller, 2014). Probably the most significant feature of this study is that these outcomes were present even when no multitasking was taking place. The study revealed that even when these chronic multitaskers focused on one task, their brains were less effective and efficient. Selective attention refers to the ability to selectively attend and process certain stimuli while ignoring others. Divided attention is needed, when two or more tasks requiring selective attention are performed in parallel. However, attention is easily caught by sudden changes in the environment. Therefore, the division of attention requires specific, higher-level cognitive processes not needed in other attention-engaging tasks.