variable affecting more than one category: 1) Predator stimuli (including movement, suddenness, proximity, but also learned and innate predator stimuli); 2) Fear is an emotional state which is aroused by threatening situations. The feeling of fear can be the direct result of certain kinds of sensory stimulation, such as sounds which resemble screaming. It can also result from the anticipation that undesirable events will possibly or certainly occur, which can motivate efforts to avoid or mitigate those events, or from imagining threats which are not a Often laboratory studies with rats are conducted to examine the acquisition and extinction of conditioned fear responses. In 2004, researchers conditioned rats (Rattus norvegicus) to fear a certain stimulus, through electric shock. The researchers were able to then cause an extinction of this conditioned fear, to a point that no medications or drugs were able to further aid in the extinction process. The rats showed signs of avoidance learning, not fear, but simply avoiding the area that brought pain to the test rats. The avoidance learning of rats is seen as a conditioned response, and therefore the behavior can be unconditioned, as supported by the earlier research. Species-specific defense reactions (SSDRs) or avoidance learning in nature is the specific tendency to avoid certain threats or stimuli, it is how animals survive in the wild. Humans and animals both share these species-specific defense reactions, such as the flight-or-fight, which also include pseudo-aggression, fake or intimidating aggression and freeze response to threats, which is controlled by the sympathetic nervous system. These SSDRs are learned very quickly through social interactions between others of the same species, other species, and interaction with the environment. These acquired sets of reactions or responses are not easily forgotten. The animal that survives is the animal that already knows what to fear and how to avoid this threat. An Russell described a more functional categorization of fear-evoking stimuli, in which for instance novelty is a variable affecting more than one category: 1) Predator stimuli (including movement, suddenness, proximity, but also learned and innate predator stimuli); 2) Physical environmental dangers (including intensity and heights); 3) Stimuli associated with increased risk of predation and other dangers (including novelty, openness, illumination, and being alone); 4) Stimuli stemming from conspecifics (including novelty, movement, and spacing behavior); 5) Species-predictable fear stimuli and experience (special evolutionary dangers); and 6) Fear stimuli that are not species predictable (conditioned fear stimuli). Species-specific defense reactions (SSDRs) or avoidance learning in nature is the specific tendency to avoid certain threats or stimuli, it is how animals survive in the wild. Humans and animals both share these species-specific defense reactions, such as the flight-or-fight, which also include pseudo-aggression, fake or intimidating aggression and freeze response to threats, which is controlled by the sympathetic nervous system. These SSDRs are learned very quickly through social interactions between others of the same species, other species, and interaction with the environment. These acquired sets of reactions or responses are not easily forgotten. The amygdala plays an important role in SSDR, such as the ventral amygdalofugal, which is essential for associative learning, and SSDRs are learned through interaction with the environment and others of the same species. An emotional response is created only after the signals have been relayed between the different regions of the brain, and activating the sympathetic nervous systems; which controls the flight, fight, freeze, fright, and faint response. Often a damaged amygdala can cause transformation in the recognition of fear (like the human case of patient S.M.). Rats will run away from any shocking event, and pigeons will flap their wings harder when threatened. The wing flapping in pigeons and the scattered running of rats are considered species-specific defense reactions or behaviors. Bolles believed that SSDRs are conditioned through Pavlovian conditioning, and not operant conditioning; SSDRs arise from the association between the environmental stimuli and adverse events. Michael S. Fanselow conducted an experiment, to test some specific defense reactions, he observed that rats in two different shock situations responded differently, based on instinct or defensive topography, rather than contextual information. Species-specific defense responses are created out of fear, and are essential for survival. Rats that lack the gene stathmin show no avoidance learning, or a lack of fear, and will often walk directly up to cats and be eaten. Animals use these SSDRs to continue living, to help increase their chance of fitness, by surviving long enough to procreate. Humans and animals alike have created fear to know what should be avoided, and this fear can be learned through association with others in the community, or learned through personal experience with a creature, species, or situations that should be avoided. It was not until 2011 that a link between severe pain, neuroinflammation and alarm pheromones release in rats was found: real time RT-PCR analysis of rat brain tissues indicated that shocking the footpad of a rat increased its production of One important characteristic of historical and mythical heroes across cultures is to be fearless in the face of big and often lethal enemies. The Magnus Archives is a fiction horror podcast written by Jonathan Sims and directed by Alexander J. Newall that, among other things, formulates an archetypal ontology of fear through the dissemination of case files at a paranormal research institute set in a world where the metaphysical basis of paranormal activity and unexplainable horrors is fear incarnate.

To survive in nature, it is crucial for animals to promptly and appropriately respond to visual information, specifically to animacy cues that pose a threat. The subcortical visual pathway is thought to be implicated in the processing of visual information necessary for these responses. In primates, this pathway consists of retina-superior colliculus-pulvinar-amygdala, functioning as a visual pathway that bypasses the geniculo-striate system (retina-lateral geniculate nucleus-primary visual cortex). In this mini review, we summarize recent neurophysiological studies that have revealed neural responses to threatening animacy cues, namely snake images, in different parts of the subcortical visual pathway and closely related brain regions in primates. The results of these studies provide new insights on (1) the role of the subcortical visual pathway in innate cognitive mechanisms for predator recognition that are evolutionarily conserved, and (2) the possible role of the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC) in the development of fear conditioning to cues that should be instinctively avoided based on signals from the subcortical visual pathway, as well as their function in excessive aversive responses to animacy cues observed in conditions such as ophidiophobia (snake phobia). The results of these studies provide new insights on (1) the role of the subcortical visual pathway in innate cognitive mechanisms for predator recognition that are evolutionarily conserved, and (2) the possible role of the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC) in the development of fear conditioning to cues that should be instinctively avoided based on signals from the subcortical visual pathway, as well as their function in excessive aversive responses to animacy cues observed in conditions such as ophidiophobia (snake phobia). Keywords: extrageniculate visual system, single unit activity, monkey, evolution, defense response status released display-pdf yes is-olf no is-manuscript no is-preprint no is-journal-matter no is-scanned no is-retracted no Received 2024 Jul 11; Accepted 2024 Aug 12; Collection date 2024. Introduction Rapid defensive responses to animacy cues that indicate a threat (e.g., from predators), such as escape and freezing, are particularly important for avoiding danger and therefore significant for the survival of animals. The neural mechanisms underlying these defensive responses are thought to be primarily innate and shared across various species (LeDoux, 2012 ). In primates, including humans, information processing through a well-developed visual system is critical for detecting biologically relevant cues. Visual stimuli are conveyed and processed through two major neuronal pathways: the canonical cortical visual pathway and the subcortical visual pathway ( Figure 1 ). The former, also known as the geniculo-striate system, sends retinal information to the visual cortex through the lateral geniculate nucleus (LGN). The information of an object that reached the visual cortex is processed in detail through the temporal cortices for its shape and color, while its spatial location and motion are mainly processed in the posterior parietal region of the cortices (Goodale and Milner, 1992 ; Kravitz et al., 2013 ). These pathways play important roles in recognizing, discriminating, Therefore, it is plausible that the mPFC and ACC receive and integrate swift visual information from the subcortical visual pathway to facilitate or modulate rapid defensive responses. In the first section of this mini review, we summarize the role of the subcortical visual pathway in innate cognitive mechanisms related to threatening animacy cues. In the second section, we discuss the potential role of the mPFC and ACC in fear conditioning to instinctively avoid cues based on signals from the subcortical visual pathway. Figure 1 Schematic of the visual pathway. LGN, lateral geniculate nucleus; V1, primary visual cortex; SC, superior colliculus; PUL, pulvinar; AMY, amygdala; PFC, prefrontal cortex. Rapid detection of snakes in the subcortical visual pathway Snakes, carnivores, and raptors are primary predators of primates during the course of evolution. Among these hunters, sightings or images of snakes evoke significant anxiety and fear in many individuals, suggesting that snakes may have been a particularly salient threat to primate survival in the past (Isbell, 2006 ). Additionally, it has been reported that presenting phobia-related words, e.g., “snake,” to individuals with animal-specific phobias increases activity in the amygdala and ACC compared to healthy controls (Britton et al., 2009 ). It should be noted, however, that such increase in activity evoked by language-related stimuli is not an innate response and it is unlikely to be caused by inputs from the SC-pulvinar visual pathway described above. Discussion In this mini review, we summarized the findings indicating functional significance of the evolutionarily conserved subcortical visual pathway for innate mechanisms involved in predator recognition in primates. We also discussed the potential role of the mPFC and ACC, which have reciprocal connections with this pathway, in processing of feared objects as instinctual avoidance signals, as exemplified by ophidiophobia. The neurocircuitry for the quick detection of threatening animacy cues may be conserved across species. During the course of evolution, primates have relied on a well-developed visual system to detect dangerous stimuli. Among many theories regarding the development of the visual system, a particularly interesting one from the point of innate defensive behavior is the “snake detection theory” (Isbell, 2006 , 2009 ). This hypothesis suggests that snakes originated prior to early primates and were their most significant predators, therefore individuals who were adept at visually detecting snakes had a higher chance of survival.

In polyandrous mating systems, one female mates with many males. These types of systems are much rarer than monogamous and polygynous mating systems. In pipefishes and seahorses, males receive the eggs from the female, fertilize them, protect them within a pouch, and give birth to the offspring (Figure 45.38). Therefore, the female is able to provide eggs to several males without the burden of carrying the fertilized eggs. The majority of the behaviors previously discussed were innate or at least have an innate component (variations on the innate behaviors may be learned). They are inherited and the behaviors do not change in response to signals from the environment. Conversely, learned behaviors, even though they may have instinctive components, allow an organism to adapt to changes in the environment and are modified by previous experiences. Simple learned behaviors include habituation and imprinting—both are important to the maturation process of young animals. Habituation is a simple form of learning in which an animal stops responding to a stimulus after a period of repeated exposure. This is

Innate behavior, or instinct, is important because there is no risk of an incorrect behavior being learned. They are “hard wired” into the system. On the other hand, learned behaviors, although riskier, are flexible, dynamic, and can be altered according to changes in the environment. Innate or instinctual behaviors rely on response to stimuli. The simplest example of this is a reflex action, an involuntary and rapid response to stimulus. To test the “knee-jerk” reflex, a doctor taps the patellar tendon below the kneecap with a rubber hammer. The stimulation of the nerves there leads to the reflex of extending the leg at the knee. This is similar to the reaction of someone who touches a hot stove and instinctually pulls his or her hand away. Even humans, with our great capacity to learn, still exhibit a variety of innate behaviors. Another activity or movement of innate behavior is kinesis, or the undirected movement in response to a stimulus. Orthokinesis is the increased or decreased speed of movement of an organism in response to a stimulus. Woodlice, for example, increase their speed of movement when exposed to high or low temperatures.

inflict upon himself the pain of amputating his foot.' He only shows the promptings of a very old and universal instinct , the instinct of self-preservation