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128-804: In humans and other animals, fear is modulated by the process of cognition and learning. Thus, fear is judged as rational and appropriate, or irrational and inappropriate (or unconscious). An irrational fear is called a phobia . Fear is closely related to the emotion anxiety , which occurs as the result of often future threats that are perceived to be uncontrollable or unavoidable. The fear response serves survival by engendering appropriate behavioral responses, so it has been preserved throughout evolution . Sociological and organizational research also suggests that individuals' fears are not solely dependent on their nature but are also shaped by their social relations and culture, which guide their understanding of when and how much fear to feel. Many physiological changes in

256-458: A Santa Claus mask with white cotton balls in the beard. Fear can be learned by experiencing or watching a frightening traumatic accident. For example, if a child falls into a well and struggles to get out, he or she may develop a fear of wells, heights ( acrophobia ), enclosed spaces ( claustrophobia ), or water ( aquaphobia ). There are studies looking at areas of the brain that are affected in relation to fear. When looking at these areas (such as

384-525: A chemical smelling of banana, and a component of bee alarm pheromone. The experiment also showed that the bees' fear-induced pain tolerance was mediated by an endorphin . By using the forced swimming test in rats as a model of fear-induction, the first mammalian "alarm substance" was found. In 1991, this "alarm substance" was shown to fulfill criteria for pheromones: well-defined behavioral effect, species specificity, minimal influence of experience and control for nonspecific arousal. Rat activity testing with

512-434: A child's psyche development or personality. For example, parents tell their children not to talk to strangers in order to protect them. In school, they would be motivated to not show fear in talking with strangers, but to be assertive and also aware of the risks and the environment in which it takes place. Ambiguous and mixed messages like this can affect their self-esteem and self-confidence. Researchers say talking to strangers

640-535: A clinical setting but no lasting effects has been shown. Mammal A mammal (from Latin mamma  'breast') is a vertebrate animal of the class Mammalia ( / m ə ˈ m eɪ l i . ə / ). Mammals are characterized by the presence of milk -producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair , and three middle ear bones . These characteristics distinguish them from reptiles and birds , from which their ancestors diverged in

768-399: A cold person warmer or a frightened animal look more impressive), sweating, increased blood glucose ( hyperglycemia ), increased serum calcium, increase in white blood cells called neutrophilic leukocytes, alertness leading to sleep disturbance and "butterflies in the stomach" ( dyspepsia ). This primitive mechanism may help an organism survive by either running away or fighting the danger. With

896-415: A comparably strong emotional response in both females and males, stress-induced sweat from females produced markedly stronger arousal in women than in men. Statistical tests pinpointed this gender-specificity to the right amygdala and strongest in the superficial nuclei. Since no significant differences were found in the olfactory bulb , the response to female fear-induced signals is likely based on processing

1024-416: A creature, species, or situations that should be avoided. SSDRs are an evolutionary adaptation that has been seen in many species throughout the world including rats, chimpanzees , prairie dogs , and even humans , an adaptation created to help individual creatures survive in a hostile world. Fear learning changes across the lifetime due to natural developmental changes in the brain. This includes changes in

1152-421: A fear-provoking situation. This suggests that fear can develop in both conditions, not just simply from personal history. Fear is affected by cultural and historical context. For example, in the early 20th century, many Americans feared polio , a disease that can lead to paralysis. There are consistent cross-cultural differences in how people respond to fear. Display rules affect how likely people are to express

1280-460: A following in America , scientists such as Wilhelm Wundt , Herman Ebbinghaus , Mary Whiton Calkins , and William James would offer their contributions to the study of human cognition. Wilhelm Wundt (1832–1920) emphasized the notion of what he called introspection : examining the inner feelings of an individual. With introspection, the subject had to be careful with describing their feelings in

1408-459: A genetic effect that is the result of natural selection . From an evolutionary psychology perspective, different fears may be different adaptations that have been useful in our evolutionary past. They may have developed during different time periods. Some fears, such as fear of heights, may be common to all mammals and developed during the mesozoic period. Other fears, such as fear of snakes, may be common to all simians and developed during

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1536-523: A high testosterone level related to unhappiness in response to androstenone in men, and a high estradiol level related to disliking of androstenone in women. A German study from 2006 showed when anxiety-induced versus exercise-induced human sweat from a dozen people was pooled and offered to seven study participants, of five able to olfactorily distinguish exercise-induced sweat from room air, three could also distinguish exercise-induced sweat from anxiety induced sweat. The acoustic startle reflex response to

1664-402: A higher level of fear. Pathogens can suppress amygdala activity. Rats infected with the toxoplasmosis parasite become less fearful of cats, sometimes even seeking out their urine-marked areas. This behavior often leads to them being eaten by cats. The parasite then reproduces within the body of the cat. There is evidence that the parasite concentrates itself in the amygdala of infected rats. In

1792-885: A major role in the Neolithic Revolution , and resulted in farming replacing hunting and gathering as the primary source of food for humans. This led to a major restructuring of human societies from nomadic to sedentary, with more co-operation among larger and larger groups, and ultimately the development of the first civilizations . Domesticated mammals provided, and continue to provide, power for transport and agriculture, as well as food ( meat and dairy products ), fur , and leather . Mammals are also hunted and raced for sport, kept as pets and working animals of various types, and are used as model organisms in science. Mammals have been depicted in art since Paleolithic times, and appear in literature, film, mythology, and religion. Decline in numbers and extinction of many mammals

1920-398: A natural pheromone-containing solution, it has been shown that the impairment was associated with defective detection of related pheromones, and with changes in their inborn preference for pheromones related to sexual and reproductive activities. Lastly, alleviation of an acute fear response because a friendly peer (or in biological language: an affiliative conspecific ) tends and befriends

2048-463: A number of variables that may have affected his ability to learn and recall the non-words he created. One of the reasons, he concluded, was the amount of time between the presentation of the list of stimuli and the recitation or recall of the same. Ebbinghaus was the first to record and plot a " learning curve " and a " forgetting curve ". His work heavily influenced the study of serial position and its effect on memory Mary Whiton Calkins (1863–1930)

2176-401: A philosophical approach to the study of cognition and the mind, with his Meditations he wanted people to meditate along with him to come to the same conclusions as he did but in their own free cognition. In psychology , the term "cognition" is usually used within an information processing view of an individual's psychological functions , and such is the same in cognitive engineering . In

2304-541: A rat perceived alarm pheromones, it increased its defensive and risk assessment behavior, and its acoustic startle reflex was enhanced. 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 proinflammatory cytokines in deep brain structures, namely of IL-1β , heteronuclear Corticotropin-releasing hormone and c-fos mRNA expressions in both

2432-402: A response to the stimulus in the form of fear or aggression commences, the amygdalae may elicit the release of hormones into the body to put the person into a state of alertness, in which they are ready to move, run, fight, etc. This defensive response is generally referred to in physiology as the fight-or-flight response regulated by the hypothalamus, part of the limbic system . Once the person

2560-414: A result of learning. This has been studied in psychology as fear conditioning , beginning with John B. Watson's Little Albert experiment in 1920, which was inspired after observing a child with an irrational fear of dogs. In this study, an 11-month-old boy was conditioned to fear a white rat in the laboratory. The fear became generalized to include other white, furry objects, such as a rabbit, dog, and even

2688-475: A separate experiment, rats with lesions in the amygdala did not express fear or anxiety towards unwanted stimuli. These rats pulled on levers supplying food that sometimes sent out electrical shocks. While they learned to avoid pressing on them, they did not distance themselves from these shock-inducing levers. Several brain structures other than the amygdalae have also been observed to be activated when individuals are presented with fearful vs. neutral faces, namely

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2816-435: A sound when sensing anxiety sweat was larger than when sensing exercise-induced sweat, as measured by electromyography analysis of the orbital muscle, which is responsible for the eyeblink component. This showed for the first time that fear chemosignals can modulate the startle reflex in humans without emotional mediation; fear chemosignals primed the recipient's "defensive behavior" prior to the subjects' conscious attention on

2944-548: A source of feedback or even stimulus change. Intrinsic feedback or information coming from within, muscle twitches, increased heart rate, are seen to be more important in SSDRs than extrinsic feedback, stimuli that comes from the external environment. Dr. Bolles found that most creatures have some intrinsic set of fears, to help assure survival of the species. Rats will run away from any shocking event, and pigeons will flap their wings harder when threatened. The wing flapping in pigeons and

3072-493: A term coined in analogy to keystone species . Pheromones may determine species compositions and affect rates of energy and material exchange in an ecological community . Thus pheromones generate structure in a food web and play critical roles in maintaining natural systems . Evidence of chemosensory alarm signals in humans has emerged slowly: Although alarm pheromones have not been physically isolated and their chemical structures have not been identified in humans so far, there

3200-476: A variety of translational animal models. These models are particularly important for research that would be too invasive for human studies. Rodents such as mice and rats are common animal models, but other species are used. Certain aspects of fear research still requires more research such as sex, gender, and age differences. Cognition Cognition is the "mental action or process of acquiring knowledge and understanding through thought, experience, and

3328-676: Is an important aspect of metacognition. Aerobic and anaerobic exercise have been studied concerning cognitive improvement. There appear to be short-term increases in attention span, verbal and visual memory in some studies. However, the effects are transient and diminish over time, after cessation of the physical activity. People with Parkinson's disease has also seen improved cognition while cycling, while pairing it with other cognitive tasks. Studies evaluating phytoestrogen , blueberry supplementation and antioxidants showed minor increases in cognitive function after supplementation but no significant effects compared to placebo . Another study on

3456-399: Is called " social buffering ". The term is in analogy to the 1985 "buffering" hypothesis in psychology, where social support has been proven to mitigate the negative health effects of alarm pheromone mediated distress. The role of a "social pheromone" is suggested by the recent discovery that olfactory signals are responsible in mediating the "social buffering" in male rats. "Social buffering"

3584-419: Is closely related to the aforementioned study and conclusion of the memory experiments conducted by Hermann Ebbinghaus. William James (1842–1910) is another pivotal figure in the history of cognitive science. James was quite discontent with Wundt's emphasis on introspection and Ebbinghaus' use of nonsense stimuli. He instead chose to focus on the human learning experience in everyday life and its importance to

3712-478: Is determined by the level of fear as well as the specific context, such as environmental characteristics (escape route present, distance to refuge), the presence of a discrete and localized threat, the distance between threat and subject, threat characteristics (speed, size, directness of approach), the characteristics of the subject under threat (size, physical condition, speed, degree of crypsis , protective morphological structures), social conditions (group size), and

3840-428: Is evidence for their presence. Androstadienone , for example, a steroidal, endogenous odorant, is a pheromone candidate found in human sweat, axillary hair and plasma. The closely related compound androstenone is involved in communicating dominance, aggression or competition; sex hormone influences on androstenone perception in humans showed a high testosterone level related to heightened androstenone sensitivity in men,

3968-511: Is gathered through observation and conscientious experimentation. Two millennia later, the groundwork for modern concepts of cognition was laid during the Enlightenment by thinkers such as John Locke and Dugald Stewart who sought to develop a model of the mind in which ideas were acquired, remembered and manipulated. During the early nineteenth century cognitive models were developed both in philosophy —particularly by authors writing about

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4096-432: 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

4224-523: Is in safe mode, meaning that there are no longer any potential threats surrounding them, the amygdalae will send this information to the medial prefrontal cortex (mPFC) where it is stored for similar future situations, which is known as memory consolidation . Some of the hormones involved during the state of fight-or-flight include epinephrine , which regulates heart rate and metabolism as well as dilating blood vessels and air passages, norepinephrine increasing heart rate, blood flow to skeletal muscles and

4352-419: Is increased, which activates processes with the expected consequence of increasing consistency and decreasing arousal." In this context, it has been proposed that fear behavior is caused by an inconsistency between a preferred, or expected, situation and the actually perceived situation, and functions to remove the inconsistent stimulus from the perceptual field, for instance by fleeing or hiding, thereby resolving

4480-415: Is learned first still has to go through a retrieval process. This experiment focuses on human memory processes. The word superiority effect experiment presents a subject with a word, or a letter by itself, for a brief period of time, i.e. 40 ms, and they are then asked to recall the letter that was in a particular location in the word. In theory, the subject should be better able to correctly recall

4608-449: Is not something to be thwarted but allowed in a parent's presence if required. Developing a sense of equanimity to handle various situations is often advocated as an antidote to irrational fear and as an essential skill by a number of ancient philosophies. Fear of the unknown (FOTU) "may be a, or possibly the, fundamental fear" from early times when there were many threats to life. Although fear behavior varies from species to species, it

4736-481: Is often divided into two main categories; namely, avoidance/flight and immobility. To these, different researchers have added different categories, such as threat display and attack, protective responses (including startle and looming responses), defensive burying, and social responses (including alarm vocalizations and submission). Finally, immobility is often divided into freezing and tonic immobility . The decision as to which particular fear behavior to perform

4864-572: Is primarily driven by human poaching and habitat destruction , primarily deforestation . Over 70% of mammal species are in the orders Rodentia , Chiroptera , and Eulipotyphla . Mammal classification has been through several revisions since Carl Linnaeus initially defined the class, and at present , no classification system is universally accepted. McKenna & Bell (1997) and Wilson & Reeder (2005) provide useful recent compendiums. Simpson (1945) provides systematics of mammal origins and relationships that had been taught universally until

4992-426: Is the time it takes for a participant to identify whether a green circle is present or not, should not change as the number of distractors increases. Conjunctive searches where the target is absent should have a longer reaction time than the conjunctive searches where the target is present. The theory is that in feature searches, it is easy to spot the target, or if it is absent, because of the difference in color between

5120-519: Is to defend themselves and at the same time to inform members of the same species of danger and leads to observable behavior change like freezing, defensive behavior, or dispersion depending on circumstances and species. For example, stressed rats release odorant cues that cause other rats to move away from the source of the signal. After the discovery of pheromones in 1959, alarm pheromones were first described in 1968 in ants and earthworms, and four years later also found in mammals, both mice and rats. Over

5248-517: The Carboniferous Period over 300 million years ago. Around 6,400 extant species of mammals have been described and divided into 27 orders . The largest orders of mammals, by number of species , are the rodents , bats , and Eulipotyphla (including hedgehogs , moles and shrews ). The next three are the primates (including humans , monkeys and lemurs ), the even-toed ungulates (including pigs , camels , and whales ), and

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5376-519: The Carnivora (including cats , dogs , and seals ). Mammals are the only living members of Synapsida ; this clade , together with Sauropsida (reptiles and birds), constitutes the larger Amniota clade. Early synapsids are referred to as " pelycosaurs ." The more advanced therapsids became dominant during the Guadalupian . Mammals originated from cynodonts , an advanced group of therapsids, during

5504-467: The Cretaceous . The relationships between these three lineages is contentious, and all three possible hypotheses have been proposed with respect to which group is basal . These hypotheses are Atlantogenata (basal Boreoeutheria), Epitheria (basal Xenarthra) and Exafroplacentalia (basal Afrotheria). Boreoeutheria in turn contains two major lineages— Euarchontoglires and Laurasiatheria . Estimates for

5632-550: The International Union for Conservation of Nature (IUCN) completed a five-year Global Mammal Assessment for its IUCN Red List , which counted 5,488 species. According to research published in the Journal of Mammalogy in 2018, the number of recognized mammal species is 6,495, including 96 recently extinct. The word " mammal " is modern, from the scientific name Mammalia coined by Carl Linnaeus in 1758, derived from

5760-547: The Latin mamma ("teat, pap"). In an influential 1988 paper, Timothy Rowe defined Mammalia phylogenetically as the crown group of mammals, the clade consisting of the most recent common ancestor of living monotremes ( echidnas and platypuses ) and therian mammals ( marsupials and placentals ) and all descendants of that ancestor. Since this ancestor lived in the Jurassic period, Rowe's definition excludes all animals from

5888-480: The Shared intentionality approach, the mother shares the essential sensory stimulus of the actual cognitive problem with the child. By sharing this stimulus, the mother provides a template for developing the young organism's nervous system. Recent findings in research on child cognitive development and advances in inter-brain neuroscience experiments have made the above proposition plausible. Based on them,

6016-459: The amygdala ), it was proposed that a person learns to fear regardless of whether they themselves have experienced trauma, or if they have observed the fear in others. In a study completed by Andreas Olsson, Katherine I. Nearing and Elizabeth A. Phelps, the amygdala were affected both when subjects observed someone else being submitted to an aversive event, knowing that the same treatment awaited themselves, and when subjects were subsequently placed in

6144-539: The biological classification scheme used, are the primates : apes , monkeys , and lemurs ; the Cetartiodactyla : whales and even-toed ungulates ; and the Carnivora which includes cats , dogs , weasels , bears , seals , and allies. According to Mammal Species of the World , 5,416 species were identified in 2006. These were grouped into 1,229  genera , 153  families and 29 orders. In 2008,

6272-416: The cenozoic time period (the still-ongoing geological era encompassing the last 66 million of history). Still others, such as fear of mice and insects, may be unique to humans and developed during the paleolithic and neolithic time periods (when mice and insects become important carriers of infectious diseases and harmful for crops and stored foods). Nonhuman animals and humans innovate specific fears as

6400-406: The paraventricular nucleus and the bed nucleus of the stria terminalis , and it increased stress hormone levels in plasma ( corticosterone ). The neurocircuit for how rats perceive alarm pheromones was shown to be related to the hypothalamus , brainstem , and amygdalae , all of which are evolutionary ancient structures deep inside or in the case of the brainstem underneath the brain away from

6528-505: The philosophy of mind —and within medicine , especially by physicians seeking to understand how to cure madness. In Britain , these models were studied in the academy by scholars such as James Sully at University College London , and they were even used by politicians when considering the national Elementary Education Act 1870 ( 33 & 34 Vict. c. 75). As psychology emerged as a burgeoning field of study in Europe , whilst also gaining

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6656-611: The prefrontal cortex and the amygdala . The visual exploration of an emotional face does not follow a fixed pattern but modulated by the emotional content of the face. Scheller et al. found that participants paid more attention to the eyes when recognising fearful or neutral faces, while the mouth was fixated on when happy faces are presented, irrespective of task demands and spatial locations of face stimuli. These findings were replicated when fearful eyes are presented and when canonical face configurations are distorted for fearful, neutral and happy expressions. The brain structures that are

6784-418: The psychological construct of Shared intentionality , highlighting its contribution to cognitive development from birth. This primary interaction provides unaware collaboration in mother-child dyads for environmental learning. Later, Igor Val Danilov developed this notion, expanding it to the intrauterine period and clarifying the neurophysiological processes underlying Shared intentionality . According to

6912-712: The shared intentionality hypothesis introduced the notion of pre-perceptual communication in the mother-fetus communication model due to nonlocal neuronal coupling. This nonlocal coupling model refers to communication between two organisms through the copying of the adequate ecological dynamics by biological systems indwelling one environmental context, where a naive actor (Fetus) replicates information from an experienced actor (Mother) due to intrinsic processes of these dynamic systems ( embodied information ) but without interacting through sensory signals. The Mother's heartbeats (a low-frequency oscillator) modulate relevant local neuronal networks in specific subsystems of both her and

7040-401: The "recipient" rat (the rat perceiving the pheromone) depending which body region they were released from: Pheromone production from the face modified behavior in the recipient rat, e.g. caused sniffing or movement, whereas pheromone secreted from the rat's anal area induced autonomic nervous system stress responses, like an increase in core body temperature. Further experiments showed that when

7168-446: The "unknown". The irrational fear can branch out to many areas such as the hereafter, the next ten years or even tomorrow. Chronic irrational fear has deleterious effects since the elicitor stimulus is commonly absent or perceived from delusions. Such fear can create comorbidity with the anxiety disorder umbrella. Being scared may cause people to experience anticipatory fear of what may lie ahead rather than planning and evaluating for

7296-417: The 15th century, where it meant " thinking and awareness". The term comes from the Latin noun cognitio ('examination', 'learning', or 'knowledge'), derived from the verb cognosco , a compound of con ('with') and gnōscō ('know'). The latter half, gnōscō , itself is a cognate of a Greek verb, gi(g)nósko ( γι(γ)νώσκω , 'I know,' or 'perceive'). Despite

7424-579: The Late Triassic to Early Jurassic . Mammals achieved their modern diversity in the Paleogene and Neogene periods of the Cenozoic era, after the extinction of non-avian dinosaurs , and have been the dominant terrestrial animal group from 66 million years ago to the present. The basic mammalian body type is quadrupedal , with most mammals using four limbs for terrestrial locomotion ; but in some,

7552-603: The acoustic startle reflex level. In analogy to the social buffering of rats and honeybees in response to chemosignals, induction of empathy by "smelling anxiety" of another person has been found in humans. A study from 2013 provided brain imaging evidence that human responses to fear chemosignals may be gender-specific . Researchers collected alarm-induced sweat and exercise-induced sweat from donors extracted it, pooled it and presented it to 16 unrelated people undergoing functional brain MRI . While stress-induced sweat from males produced

7680-455: The acquisition and development of cognitive capabilities. Human cognition is conscious and unconscious , concrete or abstract , as well as intuitive (like knowledge of a language) and conceptual (like a model of a language). It encompasses processes such as memory , association , concept formation , pattern recognition , language , attention , perception , action , problem solving , and mental imagery . Traditionally, emotion

7808-443: The alarm pheromone, and their preference/avoidance for odors from cylinders containing the pheromone, showed that the pheromone had very low volatility . In 1993 a connection between alarm chemosignals in mice and their immune response was found. Pheromone production in mice was found to be associated with or mediated by the pituitary gland in 1994. In 2004, it was demonstrated that rats' alarm pheromones had different effects on

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7936-440: The amount of experience with the type of the threat. 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

8064-485: The amygdala are generated by activation of the neurons in the region. Experimental data supports the notion that synaptic plasticity of the neurons leading to the lateral amygdalae occurs with fear conditioning. In some cases, this forms permanent fear responses such as post-traumatic stress disorder (PTSD) or a phobia . MRI and fMRI scans have shown that the amygdalae in individuals diagnosed with such disorders including bipolar or panic disorder are larger and wired for

8192-420: The beginning of cognition is memory storage about the relevant ecological dynamics by the naive nervous system (i.e., memorizing the ecological condition of relevant sensory stimulus) at the molecular level – an engram . Evidence derived using optical imaging , molecular-genetic and optogenetic techniques in conjunction with appropriate behavioural analyses continues to offer support for the idea that changing

8320-451: The beginning of the sequence, called the primacy effect , and information at the end of the sequence, called the recency effect . Consequently, information given in the middle of the sequence is typically forgotten, or not recalled as easily. This study predicts that the recency effect is stronger than the primacy effect, because the information that is most recently learned is still in working memory when asked to be recalled. Information that

8448-457: The body are associated with fear, summarized as the fight-or-flight response . An innate response for coping with danger, it works by accelerating the breathing rate ( hyperventilation ), heart rate, vasoconstriction of the peripheral blood vessels leading to blood pooling, dilating the pupils, increasing muscle tension including the muscles attached to each hair follicle to contract and causing "goosebumps", or more clinically, piloerection (making

8576-515: The brain, there are various regions of the brain involved in deciphering fear in humans and other nonhuman species. The amygdala communicates both directions between the prefrontal cortex , hypothalamus , the sensory cortex , the hippocampus , thalamus , septum , and the brainstem . 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

8704-413: The capacity to fear is part of human nature . Many studies have found that certain fears (e.g. animals, heights) are much more common than others (e.g. flowers, clouds). These fears are also easier to induce in the laboratory. This phenomenon is known as preparedness . Because early humans that were quick to fear dangerous situations were more likely to survive and reproduce; preparedness is theorized to be

8832-416: The center of most neurobiological events associated with fear are the two amygdalae , located behind the pituitary gland. Each amygdala is part of a circuitry of fear learning. They are essential for proper adaptation to stress and specific modulation of emotional learning memory. In the presence of a threatening stimulus, the amygdalae generate the secretion of hormones that influence fear and aggression. Once

8960-807: The clade originating with the last common ancestor of Sinoconodon and living mammals. The earliest-known synapsid satisfying Kemp's definitions is Tikitherium , dated 225 Ma , so the appearance of mammals in this broader sense can be given this Late Triassic date. However, this animal may have actually evolved during the Neogene. As of the early 21st century, molecular studies based on DNA analysis have suggested new relationships among mammal families. Most of these findings have been independently validated by retrotransposon presence/absence data . Classification systems based on molecular studies reveal three major groups or lineages of placental mammals— Afrotheria , Xenarthra and Boreoeutheria —which diverged in

9088-444: The closest thing to an official classification of mammals, despite its known issues. Most mammals, including the six most species-rich orders , belong to the placental group. The three largest orders in numbers of species are Rodentia : mice , rats , porcupines , beavers , capybaras , and other gnawing mammals; Chiroptera : bats; and Eulipotyphla : shrews , moles , and solenodons . The next three biggest orders, depending on

9216-410: The construction of human thought or mental processes. Jean Piaget was one of the most important and influential people in the field of developmental psychology . He believed that humans are unique in comparison to animals because we have the capacity to do "abstract symbolic reasoning". His work can be compared to Lev Vygotsky , Sigmund Freud , and Erik Erikson who were also great contributors in

9344-407: The construction of human thought or mental processes. Research shows the intentional engagement of fetuses with the environment, demonstrating cognitive achievements. However, organisms with simple reflexes cannot cognize the environment alone because the environment is the cacophony of stimuli (electromagnetic waves, chemical interactions, and pressure fluctuations). Their sensation is too limited by

9472-448: The cortex, and involved in the fight-or-flight response , as is the case in humans. Alarm pheromone-induced anxiety in rats has been used to evaluate the degree to which anxiolytics can alleviate anxiety in humans. For this, the change in the acoustic startle reflex of rats with alarm pheromone-induced anxiety (i.e. reduction of defensiveness) has been measured. Pretreatment of rats with one of five anxiolytics used in clinical medicine

9600-554: The development of the olfactory bulb and odor discrimination and it is highly expressed in developing rat brains, but absent in most regions of adult rat brains. Conditional deletion of the MAPK7gene in mouse neural stem cells impairs several pheromone-mediated behaviors, including aggression and mating in male mice. These behavior impairments were not caused by a reduction in the level of testosterone, by physical immobility, by heightened fear or anxiety or by depression. Using mouse urine as

9728-716: The disciplines of cognitive science . Metacognition is an awareness of one's thought processes and an understanding of the patterns behind them. The term comes from the root word meta , meaning "beyond", or "on top of". Metacognition can take many forms, such as reflecting on one's ways of thinking, and knowing when and how oneself and others use particular strategies for problem-solving . There are generally two components of metacognition: (1) cognitive conceptions and (2) cognitive regulation system. Research has shown that both components of metacognition play key roles in metaconceptual knowledge and learning. Metamemory , defined as knowing about memory and mnemonic strategies,

9856-498: The distractor task, they are asked to recall the trigram from before the distractor task. In theory, the longer the distractor task, the harder it will be for participants to correctly recall the trigram. This experiment focuses on human short-term memory . During the memory span experiment , each subject is presented with a sequence of stimuli of the same kind; words depicting objects, numbers, letters that sound similar, and letters that sound dissimilar. After being presented with

9984-574: The earlier Triassic , despite the fact that Triassic fossils in the Haramiyida have been referred to the Mammalia since the mid-19th century. If Mammalia is considered as the crown group, its origin can be roughly dated as the first known appearance of animals more closely related to some extant mammals than to others. Ambondro is more closely related to monotremes than to therian mammals while Amphilestes and Amphitherium are more closely related to

10112-402: The effects of herbal and dietary supplements on cognition in menopause show that soy and Ginkgo biloba supplementation could improve women's cognition. Exposing individuals with cognitive impairment (i.e. dementia ) to daily activities designed to stimulate thinking and memory in a social setting, seems to improve cognition. Although study materials are small, and larger studies need to confirm

10240-451: The end of the 20th century. However, since 1945, a large amount of new and more detailed information has gradually been found: The paleontological record has been recalibrated, and the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself, partly through the new concept of cladistics . Though fieldwork and lab work progressively outdated Simpson's classification, it remains

10368-451: 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 impairment in the recognition of fear (like the human case of patient S.M. ). This impairment can cause different species to lack

10496-415: 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 example in humans is the reaction to the sight of a snake, many jump backwards before cognitively realizing what they are jumping away from, and in some cases, it is a stick rather than a snake. As with many functions of

10624-442: 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

10752-555: The facial expression of fear and other emotions. Fear of victimization is a function of perceived risk and seriousness of potential harm. According to surveys, some of the most common fears are of demons and ghosts , the existence of evil powers, cockroaches , spiders , snakes , heights , water , enclosed spaces , tunnels , bridges , needles , social rejection , failure , examinations , and public speaking . Regionally some may more so fear terrorist attacks , death , war , criminal or gang violence , being alone ,

10880-488: The field of developmental psychology. Piaget is known for studying the cognitive development in children, having studied his own three children and their intellectual development, from which he would come to a theory of cognitive development that describes the developmental stages of childhood. Studies on cognitive development have also been conducted in children beginning from the embryonal period to understand when cognition appears and what environmental attributes stimulate

11008-439: The fields of linguistics , musicology , anesthesia , neuroscience , psychiatry , psychology , education , philosophy , anthropology , biology , systemics , logic , and computer science . These and other approaches to the analysis of cognition (such as embodied cognition ) are synthesized in the developing field of cognitive science , a progressively autonomous academic discipline . The word cognition dates back to

11136-475: The function and capacity of human memory. Ebbinghaus developed his own experiment in which he constructed over 2,000 syllables made out of nonexistent words (for instance, 'EAS'). He then examined his own personal ability to learn these non-words. He purposely chose non-words as opposed to real words to control for the influence of pre-existing experience on what the words might symbolize, thus enabling easier recollection of them. Ebbinghaus observed and hypothesized

11264-450: The future, nuclear war , flying , clowns , intimacy , people , and driving . Fear of the unknown or irrational fear is caused by negative thinking ( worry ) which arises from anxiety accompanied by a subjective sense of apprehension or dread. Irrational fear shares a common neural pathway with other fears, a pathway that engages the nervous system to mobilize bodily resources in the face of danger or threat. Many people are scared of

11392-447: 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

11520-431: The inconsistency. This approach puts fear in a broader perspective, also involving aggression and curiosity . When the inconsistency between perception and expectancy is small, learning as a result of curiosity reduces inconsistency by updating expectancy to match perception. If the inconsistency is larger, fear or aggressive behavior may be employed to alter the perception in order to make it match expectancy, depending on

11648-506: The letter when it was presented in a word than when it was presented in isolation. This experiment focuses on human speech and language. In the Brown–Peterson cohomology experiment , participants are briefly presented with a trigram and in one particular version of the experiment, they are then given a distractor task, asking them to identify whether a sequence of words is in fact words, or non-words (due to being misspelled, etc.). After

11776-451: The limbs are adapted for life at sea , in the air , in trees or underground . The bipeds have adapted to move using only the two lower limbs, while the rear limbs of cetaceans and the sea cows are mere internal vestiges . Mammals range in size from the 30–40 millimetres (1.2–1.6 in) bumblebee bat to the 30 metres (98 ft) blue whale —possibly the largest animal to have ever lived. Maximum lifespan varies from two years for

11904-476: The meaning, i.e. on the emotional level, rather than the strength of chemosensory cues from each gender, i.e. the perceptual level. An approach-avoidance task was set up where volunteers seeing either an angry or a happy cartoon face on a computer screen pushed away or pulled toward them a joystick as fast as possible. Volunteers smelling androstadienone, masked with clove oil scent responded faster, especially to angry faces than those smelling clove oil only, which

12032-404: The mind. The development of Cognitive psychology arose as psychology from different theories, and so began exploring these dynamics concerning mind and environment, starting a movement from these prior dualist paradigms that prioritized cognition as systematic computation or exclusively behavior. For years, sociologists and psychologists have conducted studies on cognitive development , i.e.

12160-411: The most objective manner possible in order for Wundt to find the information scientific. Though Wundt's contributions are by no means minimal, modern psychologists find his methods to be too subjective and choose to rely on more objective procedures of experimentation to make conclusions about the human cognitive process. Hermann Ebbinghaus (1850–1909) conducted cognitive studies that mainly examined

12288-455: The natural world. He theorized the species-specific defense reaction (SSDR). There are three forms of SSDRs: flight, fight (pseudo-aggression), or freeze. Even domesticated animals have SSDRs, and in those moments it is seen that animals revert to atavistic standards and become "wild" again. Dr. Bolles states that responses are often dependent on the reinforcement of a safety signal, and not the aversive conditioned stimuli. This safety signal can be

12416-514: The nervous system of the fetus due to the effect of the interference of the low-frequency oscillator (Mother heartbeats) and already exhibited gamma activity in these neuronal networks (interference in physics is the combination of two or more electromagnetic waveforms to form a resultant wave). Therefore, the subliminal perception in a fetus emerges due to Shared intentionality with the mother that stimulates cognition in this organism even before birth. Another crucial question in understanding

12544-529: The next two decades, identification and characterization of these pheromones proceeded in all manner of insects and sea animals, including fish, but it was not until 1990 that more insight into mammalian alarm pheromones was gleaned. In 1985, a link between odors released by stressed rats and pain perception was discovered: unstressed rats exposed to these odors developed opioid-mediated analgesia. In 1997, researchers found that bees became less responsive to pain after they had been stimulated with isoamyl acetate ,

12672-456: The noise to solve the cue problem–the relevant stimulus cannot overcome the noise magnitude if it passes through the senses (see the binding problem ). Fetuses need external help to stimulate their nervous system in choosing the relevant sensory stimulus for grasping the perception of objects. The Shared intentionality approach proposes a plausible explanation of perception development in this earlier stage. Initially, Michael Tomasello introduced

12800-542: The occipito cerebellar regions including the fusiform gyrus and the inferior parietal / superior temporal gyri. Fearful eyes, brows and mouth seem to separately reproduce these brain responses. Scientists from Zurich studies show that the hormone oxytocin related to stress and sex reduces activity in your brain fear center. In threatening situations, insects, aquatic organisms, birds, reptiles, and mammals emit odorant substances, initially called alarm substances, which are chemical signals now called alarm pheromones . This

12928-776: The oldest paradigms is the leveling and sharpening of stories as they are repeated from memory studied by Bartlett . The semantic differential used factor analysis to determine the main meanings of words, finding that the ethical value of words is the first factor. More controlled experiments examine the categorical relationships of words in free recall . The hierarchical structure of words has been explicitly mapped in George Miller 's WordNet . More dynamic models of semantic networks have been created and tested with computational systems such as neural networks , latent semantic analysis (LSA), Bayesian analysis , and multidimensional factor analysis. The meanings of words are studied by all

13056-415: The production of ultrasound , scent marking , alarm signals , singing , echolocation ; and, in the case of humans, complex language . Mammals can organize themselves into fission–fusion societies , harems , and hierarchies —but can also be solitary and territorial . Most mammals are polygynous , but some can be monogamous or polyandrous . Domestication of many types of mammals by humans played

13184-438: The release of glucose from energy stores, and cortisol which increases blood sugar, increases circulating neutrophilic leukocytes, calcium amongst other things. After a situation which incites fear occurs, the amygdalae and hippocampus record the event through synaptic plasticity . The stimulation to the hippocampus will cause the individual to remember many details surrounding the situation. Plasticity and memory formation in

13312-484: The results, the effect of social cognitive stimulation seems to be larger than the effects of some drug treatments. Transcranial magnetic stimulation (TMS) has been shown to improve cognition in individuals without dementia 1 month after treatment session compared to before treatment. The effect was not significantly larger compared to placebo. Computerized cognitive training, utilizing a computer based training regime for different cognitive functions has been examined in

13440-412: The same for letters that sound dissimilar and short words. The memory span is projected to be shorter with letters that sound similar and with longer words. In one version of the visual search experiment , a participant is presented with a window that displays circles and squares scattered across it. The participant is to identify whether there is a green circle on the window. In the featured search,

13568-570: The same. For example, "continuation of scholarly education" is perceived by many educators as a risk that may cause them fear and stress, and they would rather teach things they've been taught than go and do research. The ambiguity of situations that tend to be uncertain and unpredictable can cause anxiety in addition to other psychological and physical problems in some populations; especially those who engage it constantly, for example, in war-ridden places or in places of conflict, terrorism, abuse, etc. Poor parenting that instills fear can also debilitate

13696-642: 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

13824-417: The sensation of fear, and often can become overly confident, confronting larger peers, or walking up to predatory creatures. Robert C. Bolles (1970), a researcher at University of Washington, wanted to understand species-specific defense reactions and avoidance learning among animals, but found that the theories of avoidance learning and the tools that were used to measure this tendency were out of touch with

13952-539: The senses". It encompasses all aspects of intellectual functions and processes such as: perception , attention , thought , imagination , intelligence , the formation of knowledge , memory and working memory , judgment and evaluation , reasoning and computation , problem-solving and decision-making , comprehension and production of language . Cognitive processes use existing knowledge to discover new knowledge. Cognitive processes are analyzed from different perspectives within different contexts, notably in

14080-470: The series of physiological changes, the consciousness realizes an emotion of fear. There are observable physical reactions in individuals who experience fear. An individual might experience a feeling of dizziness, lightheaded, like they are being choked, sweating, shortness of breath, vomiting or nausea, numbness or shaking and any other like symptoms. These bodily reactions informs the individual that they are afraid and should proceed to remove or get away from

14208-503: The shrew to 211 years for the bowhead whale . All modern mammals give birth to live young, except the five species of monotremes , which lay eggs. The most species-rich group is the viviparous placental mammals , so named for the temporary organ ( placenta ) used by offspring to draw nutrition from the mother during gestation . Most mammals are intelligent , with some possessing large brains, self-awareness , and tool use . Mammals can communicate and vocalize in several ways, including

14336-434: The size of the inconsistency as well as the specific context. Aggressive behavior is assumed to alter perception by forcefully manipulating it into matching the expected situation, while in some cases thwarted escape may also trigger aggressive behavior in an attempt to remove the thwarting stimulus. In order to improve our understanding of the neural and behavioral mechanisms of adaptive and maladaptive fear, investigators use

14464-407: The stimuli, the subject is asked to recall the sequence of stimuli that they were given in the exact order in which it was given. In one particular version of the experiment, if the subject recalled a list correctly, the list length was increased by one for that type of material, and vice versa if it was recalled incorrectly. The theory is that people have a memory span of about seven items for numbers,

14592-582: The stimulus that is causing that fear. An influential categorization of stimuli causing fear was proposed by psychologist Jeffrey Alan Gray ; namely, intensity , novelty , special evolutionary dangers, stimuli arising during social interaction, and conditioned stimuli. Another categorization was proposed by Archer, who, besides conditioned fear stimuli, categorized fear-evoking (as well as aggression -evoking) stimuli into three groups; namely, pain , novelty, and frustration , although he also described " looming ", which refers to an object rapidly moving towards

14720-448: The strength of connections between neurons is one of the major mechanisms by which engrams are stored in the brain. Two (or more) possible mechanisms of cognition can involve both quantum effects and synchronization of brain structures due to electromagnetic interference. The Serial-position effect is meant to test a theory of memory that states that when information is given in a serial manner, we tend to remember information at

14848-400: The study of social cognition , a branch of social psychology , the term is used to explain attitudes , attribution , and group dynamics . However, psychological research within the field of cognitive science has also suggested an embodied approach to understanding cognition. Contrary to the traditional computationalist approach, embodied cognition emphasizes the body's significant role in

14976-410: The study of cognition. James' most significant contribution to the study and theory of cognition was his textbook Principles of Psychology which preliminarily examines aspects of cognition such as perception, memory, reasoning, and attention. René Descartes (1596–1650) was a seventeenth-century philosopher who came up with the phrase "Cogito, ergo sum", which means "I think, therefore I am." He took

15104-414: The subject is presented with several trial windows that have blue squares or circles and one green circle or no green circle in it at all. In the conjunctive search, the subject is presented with trial windows that have blue circles or green squares and a present or absent green circle whose presence the participant is asked to identify. What is expected is that in the feature searches, reaction time, that

15232-536: The target and the distractors. In conjunctive searches where the target is absent, reaction time increases because the subject has to look at each shape to determine whether it is the target or not because some of the distractors if not all of them, are the same color as the target stimuli. Conjunctive searches where the target is present take less time because if the target is found, the search between each shape stops. The semantic network of knowledge representation systems have been studied in various paradigms. One of

15360-537: The therians; as fossils of all three genera are dated about 167 million years ago in the Middle Jurassic , this is a reasonable estimate for the appearance of the crown group. T. S. Kemp has provided a more traditional definition: " Synapsids that possess a dentary – squamosal jaw articulation and occlusion between upper and lower molars with a transverse component to the movement" or, equivalently in Kemp's view,

15488-830: The visual sensors of a subject, and can be categorized as "intensity". 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). Although many fears are learned,

15616-497: The word cognitive itself dating back to the 15th century, attention to cognitive processes came about more than eighteen centuries earlier, beginning with Aristotle (384–322 BCE) and his interest in the inner workings of the mind and how they affect the human experience. Aristotle focused on cognitive areas pertaining to memory, perception, and mental imagery. He placed great importance on ensuring that his studies were based on empirical evidence, that is, scientific information that

15744-541: Was a movement known as cognitivism in the 1950s, emerging after the Behaviorist movement viewed cognition as a form of behavior. Cognitivism approached cognition as a form of computation, viewing the mind as a machine and consciousness as an executive function. However; post cognitivism began to emerge in the 1990s as the development of cognitive science presented theories that highlighted the necessity of cognitive action as embodied, extended, and producing dynamic processes in

15872-531: Was able to reduce their anxiety: namely midazolam , phenelzine (a nonselective monoamine oxidase (MAO) inhibitor), propranolol , a nonselective beta blocker , clonidine , an alpha 2 adrenergic agonist or CP-154,526 , a corticotropin-releasing hormone antagonist . Faulty development of odor discrimination impairs the perception of pheromones and pheromone-related behavior, like aggressive behavior and mating in male rats: The enzyme Mitogen-activated protein kinase 7 (MAPK7) has been implicated in regulating

16000-507: Was also observed to mitigate the conditioned fear responses of honeybees. A bee colony exposed to an environment of high threat of predation did not show increased aggression and aggressive-like gene expression patterns in individual bees, but decreased aggression. That the bees did not simply habituate to threats is suggested by the fact that the disturbed colonies also decreased their foraging. Biologists have proposed in 2012 that fear pheromones evolved as molecules of "keystone significance",

16128-419: Was an influential American pioneer in the realm of psychology. Her work also focused on human memory capacity. A common theory, called the recency effect , can be attributed to the studies that she conducted. The recency effect, also discussed in the subsequent experiment section, is the tendency for individuals to be able to accurately recollect the final items presented in a sequence of stimuli. Calkin's theory

16256-433: Was interpreted as androstadienone-related activation of the fear system. A potential mechanism of action is, that androstadienone alters the "emotional face processing". Androstadienone is known to influence the activity of the fusiform gyrus which is relevant for face recognition . Cognitive-consistency theories assume that "when two or more simultaneously active cognitive structures are logically inconsistent, arousal

16384-482: Was not thought of as a cognitive process, but now much research is being undertaken to examine the cognitive psychology of emotion; research is also focused on one's awareness of one's own strategies and methods of cognition, which is called metacognition . The concept of cognition has gone through several revisions through the development of disciplines within psychology. Psychologists initially understood cognition governing human action as information processing. This

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