Untitled

Abstract

A concept of the orientating reflex is presented, based on the principle of vector coding of cognitive and executive processes. The orientating reflex is a complex of orientating reactions of motor, autonomic, and subjective types, accentuating new and significant stimuli. Two main systems form the orientating reflex: the "targeting reaction" and the "searchlight of attention:" In the visual system, the targeting reaction ensures that the image of the object falls onto the fovea; this is mediated by involvement of premotor neurons which are excited by saccade command neurons in the superior colliculi. The "searchlight of attention" is activated as a result of resonance within the gamma frequency range, selectively enhancing cortical detectors and involving the reticular nucleus of the thalamus. Novelty signals arise in novelty neurons of the hippocampus. The synaptic weightings of neocortical detectors for hippocampal novelty neurons is initially characterized by high efficiency, which assigns a significant level of excitation of these neurons to the new stimulus. During repeated stimulation, the synaptic weightings of all the detectors representing a given stimulus decrease, with the result that the novelty signal becomes weaker. When the stimulus changes, it acts on other detectors, whose weightings for novelty neurons remain high, which strengthens the novelty signal. Decreases in the synaptic weightings on repetition of a standard stimulus form a trace of this stimulus in the novelty neurons - this is the "neural model of the stimulus." The novelty signal is determined by the non-concordance of the new stimulus with this "neural model," which is formed under the influence of the standard stimulus. The greater the difference between the new stimulus and the previously formed neural model, the stronger the novelty signal.

The adaptive pattern of the auditory N1 peak revealed by standardized low-resolution brain electromagnetic tomography

“…This component is maximally recorded at the midtemporal electrodes. Component 3 is probably from the motor and premotor cortices under the influence of the reticular formation and the ventral lateral nucleus of the thalamus, which projects to the precentral gyrus, the superior, middle and inferior frontal gyri, and the supplementary motor area on the mesial surface of the frontal lobe (Näätänen & Picton, 1987; Näätänen, 1992; Sokolov et al, 2001). The waveform of this component shows a negative peak at about 100 ms and is maximal at vertex electrodes.…”

The Role of the Entorhinal Cortex in Extinction: Influences of Aging

“…The same can be said of exploration of a new environment [14], of smelling the same odor for a long time, and so forth. The response to novelty or to a novel stimulus or set of stimuli is remarkably similar across species and stimuli, and involves arousal and movements of the eyes, ears, head, or body toward the source of the stimuli; it is called the “orienting” [22] or “what is it?” reflex [3]. The hippocampal molecular correlates of the response to a novel stimulus have been studied only recently.…”

Discriminating between ADHD adults and controls using independent ERP components and a support vector machine: a validation study

“…As for the independent components identified in the present study, BA 5 novelty component was localized in the paracentral lobule, posterior to the primary somatosensory areas. Its features are similar to the late phase of the P3a ERP component, which is thought to reflect orienting of attention towards novelty [60]. BA 6 novelty component is characterized by a prominent positive peak at 210 ms, which corresponds to the early phase of the conventional P3a component reported in various studies [60,61].…”

“…Its features are similar to the late phase of the P3a ERP component, which is thought to reflect orienting of attention towards novelty [60]. BA 6 novelty component is characterized by a prominent positive peak at 210 ms, which corresponds to the early phase of the conventional P3a component reported in various studies [60,61]. This early P3a subcomponent has been assumed to reflect the breaking of regularity in the environment [60].…”