Influential+Researchers+and+their+Key+Findings

Influential Researchers and their Key Findings Wilhelm Wundt 1832 - 1920 In 1875, Wilhelm Wundt became one of the founding fathers of experimental psychology when he published The Principles of Physiological Psychology. This was the first textbook published about experimental psychology and soon after set up the first experimental psychology laboratory. In 1899, Wundt wrote a monograph on the use of tachistoscopes, a device that reveals visual stimuli very briefly, during psychological research and came to conclusions about perception based on these studies (Blumenthal, 1975). In American Psychologist Blumenthal states the conclusions as "(1) the effective duration of a percept is not identical with the duration of the stimulus—but rather reflects the duration of a psychological process; (2) the relation between accuracy of a perception and stimulus duration depends on pre- and postexposure fields (which may induce what we now call masking); and (3) central processes, rather than peripheral sense organ after effects, determine these critical times" (p. 1085-1086). Wundt performed many reaction time studies following this and made inferences about how humans processed information based on the data. These early experiments were the beginning of information-processing models and are still used frequently today (Blumenthal, 1975).

John Ridley Stroop 1897 - 1973 John Ridley Stroop is responsible for creating one of the most quintessential, implemented examples of interference to attention. The effect was first published in The Journal of Experimental Psychology in 1935 The Stroop Effect consists of asking a subject to identify the color of the text when the text is a word of a different color. Participants generally struggle with responding at the rate of which they would if the color of the text and printed word were the same. This effect has spawned over 700 published studies, and has greatly affected the field of cognitive psychology. The reason why the Stroop Effect is so widely studied is because it touches on two important ideas in cognitive psychology. The first is that some processes, such as reading words, are automated. The second idea is that some processes are performed faster than others which affect the slower processes. Almost 80 years later, studies are still being conducted on the predicament that Stroop has created and it remains a valuable puzzle for cognitive psychologists (MacLeod, 1991). Donald Broadbent 1926 - 1993 Donald Broadbent was one of the first researchers to introduce the idea that an organism could be researched as an information processing system. Perception and Communication (1958), arguably his most influential work, outlined procedures for interpreting human behaviors as an information processing system. The timing of the release brought new ideas to a field that was dominated by Behaviorism. The model presented, which was known as the Broadbent Filter Model, was the first testable selective filter model introduced. The idea behind his selective filter model, was that the brain receives information through many channels, but interpreted by one channel. When this channel receives too much information it filters out information and stores it in the short term memory until the main channel is able to process it. Because this model was testable it promoted other researches to challenge its validity, further increasing research in the field. This paved the way for several later models; Broadbent also released a revised model in 1978 (Craik & Baddeley, 1995). Anne Treisman 1935 - Current Anne Treisman has been a prominent figure in attention research throughout her entire career. She has won several awards from the APA and currently is a senior researcher at Princeton University. Soon after Broadbent had released his Filter Theory, Treisman introduced her own filter model. This model was called the Attenuation Model. Instead of only being comprised of one component, only the selective filter, the model also contained a second component which was referred to as as a dictionary, words that easily draw our attention. The selective filter would be used to identify a message based on pitch, distance, or volume and the newly added dictionary component would allow for distinction between two messages based on what they contain (Iris, 1997). Treisman also introduced the Feature-Integration Theory, known as FIT, which is a two-stage theory that attempts to explain how we process visual stimuli. In the first stage, we perceive unconsciously details of the object such as shape or color. During the second stage, our attention is directed on the object to combine the individual features of the object with the information gained in the first stage (Treisman & Gelade, 2012). The Feature-Integration Theory is still relevant today (Iris, 1997). Michael Posner 1936 - Current Michael Posner is considered a pioneer in the linking of cognitive psychology to neuroscience. Working with Oscar Marin, a neurologist, he was able to determine which brain regions were used for different processes of attention. By utilizing patients with damage to certain parts of the brain, Marin and Posner were able to form a network of brain processes regarding attention. This method of research is still widely used today. Posner moved on to studying the basic processes of the brain by using the PET scan to monitor the blood flow within the brain to determine the locations of each process. In 1994, in conjunction with Raichle Posner wrote Images of Mind, which outlined his studies and contributions to neurological mapping. Switching his research to the development of attention in children, Posner began experiments that would vastly improve the knowledge about attention deficit disorders. By examining eye motion in reaction to stimuli in infants, Posner was able to compare the same stimuli to older children. From this, Posner was able to see how attention progressed in children. Information from these studies led him to study the maturation of the anterior and posterior attention networks. Posner's research on elementary processes in the brain has benefited not only the understanding of attention, but the understanding of the brain as a whole (Keele & Mayr, 2005). Russel Barkley 1949 - Current Russel Barkley is a lifetime researcher and expert in attention deficit disorders. He currently teaches at the Medical University of South Carolina, with a PhD in clinical psychology. In 1997, He published his Unifying Theory of ADHD, which Barkley (1997) states "attempt[s] to provide a unifying model of ADHD that is founded on prior theories of the neuropsychological functions of the brain's prefrontal lobes" (p. 66). Barkley argues that behavioral inhibition is one of the main triggers that cause ADHD.

His operational definition of behavioral inhibition lists three interconnected neurological processes:

 a. "inhibition of the initial prepotent response to an event" (p. 67) b. "stopping of an ongoing response, which thereby permits a delay in the decision to respond" (p. 67) <span style="font-family: Tahoma,Geneva,sans-serif;">c. "the protection of this period of delay and the self-directed responses that occur within it from disruption by competing events and responses (interference control)" (p. 67) <span style="font-family: Tahoma,Geneva,sans-serif;"> <span style="font-family: Tahoma,Geneva,sans-serif;">The reasons he applies so much weight to behavioral inhibition is because it interrupts five other neuropsychological abilities which rely on behavioral inhibition to function efficiently.

<span style="font-family: Tahoma,Geneva,sans-serif;">These abilities, which the lack of also are typical symptoms of ADHD, are defined as:

<span style="font-family: Tahoma,Geneva,sans-serif;">"(a) self-directed actions; <span style="font-family: Tahoma,Geneva,sans-serif;">(b) the organization of behavioral contingencies across time; (c) the use of self-directed speech, rules, or plans; (d) deferred gratification (e) goal-directed, future-oriented, purposive, or intentional actions." (p. 67)

<span style="font-family: Tahoma,Geneva,sans-serif;"> With Barkley's unifying theory, the linking of the executive functions with the common symptoms of ADHD is a key finding that gives researchers new questions and new treatment options (Barkley, 1997).