Perceptual system

About: Perceptual system is a research topic. Over the lifetime, 769 publications have been published within this topic receiving 29968 citations.

Perceptual symbol systems.

Abstract: Prior to the twentieth century, theories of knowledge were inherently perceptual. Since then, developments in logic, statis- tics, and programming languages have inspired amodal theories that rest on principles fundamentally different from those underlying perception. In addition, perceptual approaches have become widely viewed as untenable because they are assumed to implement record- ing systems, not conceptual systems. A perceptual theory of knowledge is developed here in the context of current cognitive science and neuroscience. During perceptual experience, association areas in the brain capture bottom-up patterns of activation in sensory-motor areas. Later, in a top-down manner, association areas partially reactivate sensory-motor areas to implement perceptual symbols. The stor- age and reactivation of perceptual symbols operates at the level of perceptual components - not at the level of holistic perceptual expe- riences. Through the use of selective attention, schematic representations of perceptual components are extracted from experience and stored in memory (e.g., individual memories of green, purr, hot). As memories of the same component become organized around a com- mon frame, they implement a simulator that produces limitless simulations of the component (e.g., simulations of purr). Not only do such simulators develop for aspects of sensory experience, they also develop for aspects of proprioception (e.g., lift, run) and introspec- tion (e.g., compare, memory, happy, hungry). Once established, these simulators implement a basic conceptual system that represents types, supports categorization, and produces categorical inferences. These simulators further support productivity, propositions, and ab- stract concepts, thereby implementing a fully functional conceptual system. Productivity results from integrating simulators combinato- rially and recursively to produce complex simulations. Propositions result from binding simulators to perceived individuals to represent type-token relations. Abstract concepts are grounded in complex simulations of combined physical and introspective events. Thus, a per- ceptual theory of knowledge can implement a fully functional conceptual system while avoiding problems associated with amodal sym- bol systems. Implications for cognition, neuroscience, evolution, development, and artificial intelligence are explored.

Cerebral specialization and interhemispheric communication: does the corpus callosum enable the human condition?

Abstract: Summary The surgical disconnection of the cerebral hemispheres half-brain. By having the callosum serve as the great communication link between redundant systems, a precreates an extraordinary opportunity to study basic existing system could be jettisoned as new functions neurological mechanisms: the organization of the sensory developed in one hemisphere, while the other hemisphere and motors systems, the cortical representation of the could continue to perform the previous functions for both perceptual and cognitive processes, the lateralization of half-brains. Split-brain studies have also revealed the function, and, perhaps most importantly, how the divided complex mosaic of mental processes that participate in brain yields clues to the nature of conscious experience. human cognition. And yet, even though each cerebral Studies of split-brain patients over the last 40 years hemisphere has its own set of capacities, with the left have resulted in numerous insights into the processes of hemisphere specialized for language and speech and perception, attention, memory, language and reasoning major problem-solving capacities and the right abilities. When the constellation of findings is considered hemisphere specialized for tasks such as facial recognition as a whole, one sees the cortical arena as a patchwork of and attentional monitoring, we all have the subjective specialized processes. When this is considered in the light experience of feeling totally integrated. Indeed, even of new studies on the lateralization of functions, it becomes though many of these functions have an automatic quality reasonable to suppose that the corpus callosum has to them and are carried out by the brain prior to our enabled the development of the many specialized systems conscious awareness of them, our subjective belief and by allowing the reworking of existing cortical areas feeling is that we are in charge of our actions. These while preserving existing functions. Thus, while language phenomena appear to be related to our left hemisphere’s emerged in the left hemisphere at the cost of pre-existing interpreter, a device that allows us to construct theories perceptual systems, the critical features of the bilaterally about the relationship between perceived events, actions and feelings. present perceptual system were spared in the opposite

Brain states: top-down influences in sensory processing.

Abstract: All cortical and thalamic levels of sensory processing are subject to powerful top-down influences, the shaping of lower-level processes by more complex information. New findings on the diversity of top-down interactions show that cortical areas function as adaptive processors, being subject to attention, expectation, and perceptual task. Brain states are determined by the interactions between multiple cortical areas and the modulation of intrinsic circuits by feedback connections. In perceptual learning, both the encoding and recall of learned information involves a selection of the appropriate inputs that convey information about the stimulus being discriminated. Disruption of this interaction may lead to behavioral disorders, including schizophrenia.

The neural systems that mediate human perceptual decision making.

Abstract: Perceptual decision making is the act of choosing one option or course of action from a set of alternatives on the basis of available sensory evidence. Thus, when we make such decisions, sensory information must be interpreted and translated into behaviour. Neurophysiological work in monkeys performing sensory discriminations, combined with computational modelling, has paved the way for neuroimaging studies that are aimed at understanding decision-related processes in the human brain. Here we review findings from human neuroimaging studies in conjunction with data analysis methods that can directly link decisions and signals in the human brain on a trial-by-trial basis. This leads to a new view about the neural basis of human perceptual decision-making processes.