Early and Late Selection Models of Attention - Research Paper Example

? Early and Late Selection Models of Attention - Early and Late Selection Models of Attention Abstract Over the last few years, the “mechanism of attention” has been the focus of research. This paper describes how the issue of “ignoring irrelevant distractors” has led to the development of Early and Late Selection models of attention. However, the main aim of the paper is to contrast between early and late selection theories of attention. At the end paper explains why it is difficult for humans to focus and effectively carry out two distinct tasks simultaneously. Introduction   Broadbent’s filter theory, presented in 1958, highlights ‘early selection’ approaches and is considered to be a classic example in that particular field. This theory argues that a response against attended vs. unattended information is generated and differs early in perceptual processing. But it was later suggested that unattended information may not be completely blocked and may be processed more deeply. On the other hand, late selectionists argued that these unattended stimuli might undergo full perceptional processing but the person may not deliberately show a response based on these processing outcomes. During 1950s, most of the work on the subject of selective attention was focused on audition but from 1960 onward, most of the attention was laid on the visual component of selective attention. (Driver 2001). The process of selection is a fundamental aspect of our cognitive activity. The mechanisms of attention allow us to focus on a portion of information from the vast amount of information confronting us. For example, the process of attention enables an individual to locate his friend in a noisy night club. The limitation of human cognition is a fundamental empirical phenomenon that enables the human brain to select the information relevant to us from the vast amount of information impinging upon our senses at any moment. Recent studies on the phenomenon of cognitive limitation have revealed that the human brain is simply not capable of processing the array of information it is constantly bombarded with. Moreover, it appears that some of the information received by the brain is lost during the process of selection. As it is not mandatory for the human brain to process all the information therefore, it uses the process of selection to focus on the portion of information relevant to us. Selective attention is the term which is used to describe the mechanism involved in the process of selection. (Cohen 2012). The process of selection can only occur in the availability of some information. Therefore, prior to process of selection, a pre-attentive process must be performed in order to generate an output which will subsequently be used in the selection process. In order to explore the basic properties of selective attention, researchers have been conducting extensive studies for the last 50 years. (Cohen 2012). Dual Stage Two Phase Model of Selective Attention The dual stage two phase model (DSTP) consist of two different stages of stimulus selection; early stage and a late stage. To understand the difference between these two stages, it is important to perceive and understand the characteristics of human behavior that are controlled by both internal and external factors. Although, external forces in the environment can be very useful in controlling a certain behavior by eliciting a response to specific behaviors, it is the internal factors that are more efficient at the activation of goal oriented responses. Selective attention is one important internal control mechanism. Whether, selection is achieved early or late in the stimulus processing is still a topic of debate. But, a general picture can be obtained by highlighting the differences between these two stages. The early stage of selection accounts utilizes the information available at the pre-identification stages which occurs early in the process and is based on features of elementary stimulus. One highlighting feature of early stage selection is that only one object at a time is selected for identification and is processed further. On the other hand, late selection accounts identify various stimuli simultaneously and then choose a target stimulus for further processing. This processing is based upon identity and other semantic features and takes place at a later stage. There are various theories that states that early and late selection are actually two modes of attention and that either of these two modes can be used depending on costs and benefits. Latest evidences have shown that these theories are applicable by demonstrating that modes of selective attention can be chosen strategically. But, besides supporting these theories, the latest understanding has raised many questions such as if early and late selection modes can be activated at the same time. Moreover, the exact nature of their interaction is still not clear. (Hubner, Steinhauser & Lehle 2010). Early Versus Late Selection The act of task performance has two major components, firstly is the input (through our senses) which initiates the process of processing the stream of information, secondly the output in which the process ends. In most instances, the output is usually a behavioral action in response to the input. (Cohen 2012). The core property of all perceptual and cognitive operations is the act of attention. With the help of limited cognitive processing, the mechanisms of attention undertake the process of selecting, modulating, and sustaining focus on potent information. This potent information is responsible for mediating the behavioral action which will occur after processing the selective information. According to Lavie’s overarching theory of attention, the perceptual load can be distinguished from central limitations. Central load is responsible the performance of executive functions such as task switching and increasing working memory. The difference between central load and perceptual load is that the effects of central load on distractor processing are usually the opposite of those mediated by perceptual load manipulations. The first difference between early and late selection models of attention is the fact that the late selection is usually a result of manipulations of central attention. Therefore, full perceptual identification of ignored items is a result of late selection process. (Chun, Golomb & Turk-Browne 2011). In early selection, the process of selection is preceded by the processing of physical characteristics of the message. On the other hand, in late selection, the processing of physical characteristics and meaning of the message are processed before the actual process of selection is initiated. (Goldstein 2008). The early selection view includes the attention which as he capability to prevent distractor perception. However, certain studies show the accumulation of irrelevant distractors in some individuals. Whereas, the late selection view holds the opposite position and involves the attention in which the perception of the distractors cannot be prevented but the distractors themselves can be excluded from the postperceptual processes. The process of early selection occurs during high perceptual load situations. The high perceptual load situations include the situations in which multiple relevant stimuli are presented to our senses. Conversely, the process of late selection occurs during situations having a characteristic low perceptual load. The situations which are classified as having low perceptual load are those in which only a single relevant situation is presented to the human senses. The reason why late selection occurs during low perceptual load situations is due to the property of the relevant perception to leave spare capacity. This spare capacity results in spilling over which causing the processing of irrelevant information and items. (Lavie & de, F. J. W. 2003). The issue of unconscious processing is the critical difference between early and late selection views on attention. The studies conducted on divided attention have resulted in the genesis of the issues over unconscious processing. According to the early selection view, the attention is not switched to the unattended message due to the presence of a stringent response to the attended message. On the other hand, late selection theories argue that the meaning of the messages is activated but response occurs only to a single type of message because it is not possible to develop a response to two different types of messages at one time. Therefore, most researchers suggest that the difficulty experienced during the performance of two different tasks simultaneously is a result of combined effects of both early and late selections of attention. Therefore, this suggests that attention should not be considered as a selective filter which has a position at one point in the processing sequence. The early and late selections theories disagree over the existence of short lived effects of unconscious processing. On the other hand, these theories deny the long term effects of unconscious processing on later behavior. (Hunt 2006). Conclusion The integral component of the process of selection is the limited cognition of the human brain. The cognitive limitation allows the human brain to select and focus on the information that is relevant while at the same time ignoring the irrelevant information. However, various studies indicate the possibility that not all individuals are capable of successfully ignoring irrelevant information and such individuals the performance is often interfered by irrelevant items. The extent to which the irrelevant distractors can be ignored has been the focus of attention for years and has resulted in two distinct views i.e. early and late selection models of attention. The selection processes are responsible for making it difficult for us to handle and carry out two distinct tasks simultaneously, which indicate that both processes work concomitantly. References: Chun, M. M., Golomb, J. D., & Turk-Browne, N. B. (January 01, 2011). A taxonomy of external and internal attention. Annual Review of Psychology, 62, 73-101. http://web.mit.edu/~jgolomb/www/ChunGolombTurkbrowne_2011ARP.pdf Cohen, A. Selective Attention. The Hebrew University, Israel. Accessed on 21st July 2012. Driver, J. (January 01, 2001). A selective review of selective attention research from the past century. British Journal of Psychology (london, England : 1953), 92, 53-78. Goldstein, E. B. (2008). Cognitive psychology: Connecting mind, research, and everyday experience. Australia: Thomson Wadsworth. http://micro5.mscc.huji.ac.il/~acohenlab/files/ency_final.pdf http://www.icn.ucl.ac.uk/attention/pubs/Jon%20Driver/Author/Original%20Research%20Papers/2001/Brit%20J%20Psychology%2092%2053%2078.pdf Hubner, R., Steinhauser, M., & Lehle, C. (July 01, 2010). A dual-stage two-phase model of selective attention. Psychological Review, 117, 3, 759-784. http://kops.ub.uni-konstanz.de/bitstream/handle/urn:nbn:de:bsz:352-opus-127519/Hubneral_10_PR_neugescannt.pdf?sequence=1 Hunt. (April 01, 2006). Fundamentals of Cognitive Psych. Tata McGraw-Hill Education. Lavie, N., & de, F. J. W. (January 01, 2003). Contrasting effects of sensory limits and capacity limits in visual selective attention. Perception & Psychophysics, 65, 2, 202-12. http://www.psychol.ucl.ac.uk/attention.lab/reprints/reprint-limits.pdf Read More