Top-down control

Extracted Attributes

• Synonyms

  Stepwise design, stepwise refinement, decomposition, command-and-control

• Primary Fields

  Management, Information Processing, Software, Cognitive Psychology, Ecology

• Management Style

  Hierarchical, centralized decision-making with one-way information flow

• Cognitive Definition

  Information processing influenced by internal factors like context, learning, and expectation

• System Design Method

  Breaking down a system into subsystems to reach base elements

• Ecological Definition

  Predator-controlled food web where top organisms regulate lower trophic levels

Timeline

• Chun and Jiang publish research on top-down attentional guidance based on implicit learning. (Source: Web search: Top-Down Processing - The Decision Lab)

  1999-01-01

• Hopfinger, Buonocore, and Mangun identify involuntary forms of top-down attentional control. (Source: Web search: Top-Down Does Not Mean Voluntary)

  2000-01-01

• Fries et al. report on top-down anticipatory control mechanisms within the prefrontal cortex. (Source: Web search: Top-Down Anticipatory Control in Prefrontal Cortex)

  2001-01-01

• Koch Industries acquires Georgia-Pacific, subsequently dismantling its 51-story top-down hierarchy. (Source: Document 55c5ba4c-d2b8-4c11-b9ca-1afc406bc189; Wikipedia)

  2005-12-23

• Awh, Belopolsky, and Theeuwes define top-down control as attentional control driven by internal factors. (Source: Web search: Top-Down Does Not Mean Voluntary)

  2012-01-01

• Theeuwes argues that top-down control is less common in visual attention than typically assumed. (Source: Web search: Top-Down Does Not Mean Voluntary)

  2018-01-01

Bottom-up and top-down approaches

Bottom-up and top-down are strategies of composition and decomposition in fields as diverse as information processing and ordering knowledge, software, humanistic and scientific theories (see systemics), time management, and organization. In practice they can be seen as a style of thinking, teaching, or leadership. A top-down approach (also known as stepwise design and stepwise refinement and in some cases used as a synonym of decomposition) is essentially the breaking down of a system to gain insight into its compositional subsystems in a reverse engineering fashion. In a top-down approach an overview of the system is formulated, specifying, but not detailing, any first-level subsystems. Each subsystem is then refined in yet greater detail, sometimes in many additional subsystem levels, until the entire specification is reduced to base elements. A top-down model is often specified with the assistance of black boxes, which makes it easier to manipulate. However, black boxes may fail to clarify elementary mechanisms or be detailed enough to realistically validate the model. A top-down approach starts with the big picture, then breaks down into smaller segments. A bottom-up approach is the piecing together of systems to give rise to more complex systems, thus making the original systems subsystems of the emergent system. Bottom-up processing is a type of information processing based on incoming data from the environment to form a perception. From a cognitive psychology perspective, information enters the eyes in one direction (sensory input, or the "bottom"), and is then turned into an image by the brain that can be interpreted and recognized as a perception (output that is "built up" from processing to final cognition). In a bottom-up approach the individual base elements of the system are first specified in great detail. These elements are then linked together to form larger subsystems, which then in turn are linked, sometimes in many levels, until a complete top-level system is formed. This strategy often resembles a "seed" model, by which the beginnings are small but eventually grow in complexity and completeness. But "organic strategies" may result in a tangle of elements and subsystems, developed in isolation and subject to local optimization as opposed to meeting a global purpose.

Web Search Results

• The top-down vs bottom-up control in an ecosystem – Eco-intelligent

  Therefore, the populations in each trophic level need to be kept in check and not be left to drift around. For a stable and diversified ecosystem, the system itself needs to come up with ways to control the populations of all its species and make sure it remains in the most suitable range. Scientists have proposed two-models of population control and energy flux in an ecosystem. ## The top-down control In the top-down control, the populations of the organisms lower trophic levels (bottom of the pyramid) are controlled by the organisms at the top. This approach is also called the predator-controlled food web of an ecosystem. The ecological pyramid, describing trophic layers in the ecosystem. [...] The “top-down” or “bottom-up” refers to the ecological pyramid describing trophic levels. Image source: Your Article Library For instance… Imagine a simplified ecosystem where there are plants, deer and tigers. The plants are the producers, the deer are the herbivores and the tigers are the top carnivores. The presence of tigers keep the deer population in check. If there were no tigers in this ecosystem, then the deer population rapidly increase. As a result, all the plants would be eaten. When almost all the plants are eaten by the huge, unsustainable population of deer, there is no food left for the deer. So, that population of deer would eventually starve to death and the ecosystem would collapse. [...] In reality, there are many more carnivores, herbivores and producers in an ecosystem. This adds a great degree of complexity into this approach, which is the reason for it’s success. More the number of predators or top consumers in an ecosystem, greater is the control established on the herbivores in case of the top-down approach.The same will be true for the bottom-up approach. Isn’t nature magical? The top-down and bottom-up control is a structure that governs the flow of energy within ecosystems. For more on flow of energy, check out: Y-shaped energy flow model: Who eats whom in nature. Further reading: 1. Interaction between top-down and bottom-up control in marine food webs 2. Are ecosystems structured top-down or bottom-up? A new look at an old debate

• “Top-down” Does Not Mean “Voluntary” | Journal of Cognition

  It is worth mentioning that many researchers advocating for selection history have avoided conflating top-down processing with volition. Most notably, a recent review by Awh, Belopolsky, and Theeuwes (2012) defined top-down control as “attentional control that is driven by factors that are ‘internal’ to the observer” (p. 437). This effectively defines top-down as everything that is not bottom-up, forming a clean dichotomy that is consistent with historical usage of the term “top-down.” That article made a compelling argument that the top-down/bottom-up dichotomy has been problematic as a research strategy, because some forms of top-down control are voluntary, slow, and controlled, whereas others are largely involuntary, fast, and automatic. However, this implies that the field should [...] Attention researchers have long debated the roles of top-down and bottom-up mechanisms in controlling attention. Theeuwes (2018) has argued that that top-down control is much less common than typically assumed and that a third mechanism—selection history—plays an underappreciated role in guiding visual attention. Although Theeuwes has made a strong case for the importance of selection history, his arguments for a limited role of top-down mechanisms involve conflating the terms “top-down” and “voluntary.” Cognitive psychologists typically use the term “top-down” processing to refer to any perceptual phenomenon that is influenced by context, learning, or expectation, which would include selection history. This highlights a broad problem in attention capture research: The terms used to [...] attentional control” (Hopfinger, Buonocore, & Mangun, 2000, p. 284), implies that there are also involuntary forms of top-down control (because otherwise the modifier would be unnecessary). Similarly, Baluch and Itti (2011) are cited because they used the phrase “volitional top-down process.” But the glossary of that paper clearly distinguishes between volitional top-down processes and top-down processes more generally. A “top-down process” is defined by Baluch and Itti as “…an automatic, percept-modifying [top-down] mechanism that is pervasive and that volition cannot completely eliminate.” (p. 210). Similarly, a classic study of contextual cuing (Chun & Jiang, 1999) is titled, “Top-down attentional guidance based on implicit learning of visual covariation,” which makes a clear

• [PDF] Top-Down Anticipatory Control in Prefrontal Cortex

  synaptic gain of neurons in target sensory populations (Fries et al. 2001). ‘Bottom-up’ and ‘top-down’ are heuristic terms used to describe the interplay of exogenous (feedforward) and endogenous (feedback) neuronal activities within the cortex. Onset of a visual stimulus initiates a flow of activity along the geniculostriate pathway, which induces a state change from anticipation to active processing of the stimulus pattern features. The stimulus-driven bottom-up processing is largely subserved by sensory association cortexes. The traditional approaches that emphasize this bottom-up processing have been remarkably successful in our understanding of sensory processing in the brain, yet it becomes apparent that key features in cortical processing are neglected considering sensory [...] has been repeatedly reported (e.g., Driver and Frith 2000). However, the mechanism that explains the biased attentional effects remains elusive. The search for the mechanisms of top-down control becomes equivalent to the investigation of the influence of ongoing activity in higher cortical areas such as PFC on the processing of sensory signals in lower cortical areas such as primary visual cortex, and, in particular, on the behavioral performance. It is essentially the question as to how the anticipatory attention, prestimulus cortical activity and behavioral performance are linked. Our hypothesis is that the PFC exerts top-down modulatory biased signals in terms of oscillatory patterns and synchronization before stimulus appearance, which leads to variability in performance. We describe [...] in cortical processing are neglected considering sensory processing as strictly bottom-up (Engel et al. 2001). An alternative view is that predictions or hypotheses about the features of environmental stimuli and goals about the current tasks are expressed by signals traveling along top-down connections from higher to lower cortical areas. As opposed to the bottom-up activity, the top-down activity is a highly selective process based on cognitive expectations and is typically subserved by the frontal systems of the brain. According to this view, therefore, the sensory and perceptive process is not just a passive bottom-up process, but is also directly influenced by higher-order internal brain processes like preparation, expectation, attention or planning, to name a few, which are

• Top-Down vs. Bottom-Up Management: What Is the Best Fit?

  ## Top-down management Often referred to as command-and-control, top-down management is often the default. In this hierarchical style of management, the power and decision-making generally remain with those at the top (though there might be some input from middle management). Information tends to flow slowly and only in one direction. It’s up to everyone else to implement the vision that’s determined by the leadership team. The top-down approach comes with several benefits. First, because the decision-making process is extremely centralized, it leaves little room for ambiguity. With the input of just a few people, it’s easy to provide clarity, and the message doesn’t get muddled or crowded with additional revisions and perspectives. A clearer vision is much easier to implement. [...] The cliche of the boss-as-tyrant or boss-as-benevolent dictator or boss-as-all-knowing is prevalent for a reason. Most of us are used to top-down management — the traditional approach. The leadership team sets the company’s direction and major projects, and everyone else executes the plan. At the extreme, the employees execute tightly-specified tasks as quickly, consistently — and robotically — as possible.

• Top-Down Processing - The Decision Lab

  Top-down processing gets its name from the literal and figurative model of how information is processed in the human brain. Information from our senses typically enters the brain from below, near the spinal cord. From there, it travels up and forward through the brain, undergoing progressively more complex processing, until it reaches the frontal areas that are responsible for higher-order functions such as decision-making, impulse control, and motivation.1,2 The “top” in “top-down” refers to these higher-order functions. [...] Top-down processing is the mechanism that allows us to subconsciously swap letters within a word or tune out background noise when we’re focused. Unlike bottom-up processing, which relies on the stimuli around us to build our mental representations of the world, top-down processing recruits our memories, goals, and knowledge to shape our experiences.1 The effect is at the level of perception; in the case of sneaky typos, our expectations influence our conscious experience, causing us to miss those minor errors.