Sense of agency The "sense of agency" (SA) refers to the subjective awareness that one is initiating, executing, and controlling one's own volitional actions in the world.[1] It is the pre-reflective awareness or implicit sense that it is I who is executing bodily movement(s) or thinking thoughts. In normal, non-pathological experience, the SA is tightly integrated with one's "sense of ownership" (SO), which is the pre-reflective awareness or implicit sense that one is the owner of an action, movement or thought. If someone else were to move your arm (while you remained passive) you would certainly have sensed that it were your arm that moved and thus a sense of ownership (SO) for that movement. However, you would not have felt that you were the author of the movement; you would not have a sense of agency (SA).[2] Definition[edit] Neuroscience of the sense of agency[edit] Agency and psychopathology[edit] Marc Jeannerod proposed that the process of self-recognition operates covertly and effortlessly.
Range fractionation Range fractionation is a term used in biology used to denote varying firing thresholds for different stimuli intensities. Sense organs are usually composed of many sensory receptors measuring the same property. These sensory receptors show a limited degree of precision due to an upper limit in firing rate. ^ Campbell, J.; et al. (1968). Pareidolia A satellite photo of a mesa in Cydonia, often called the Face on Mars. Later imagery from other angles did not contain the illusion. Examples[edit] Projective tests[edit] The Rorschach inkblot test uses pareidolia in an attempt to gain insight into a person's mental state. The Rorschach is a projective test, as it intentionally elicits the thoughts or feelings of respondents which are "projected" onto the ambiguous inkblot images. Art[edit] In his notebooks, Leonardo da Vinci wrote of pareidolia as a device for painters, writing "if you look at any walls spotted with various stains or with a mixture of different kinds of stones, if you are about to invent some scene you will be able to see in it a resemblance to various different landscapes adorned with mountains, rivers, rocks, trees, plains, wide valleys, and various groups of hills. Religious[edit] Divination[edit] Various European ancient divination practices involve the interpretation of shadows cast by objects. Fossils[edit]
Receptive field Delimited medium where some stimuli can evoke neuronal responses Complexity of the receptive field ranges from the unidimensional chemical structure of odorants to the multidimensional spacetime of human visual field, through the bidimensional skin surface, being a receptive field for touch perception. Receptive fields can positively or negatively alter the membrane potential with or without affecting the rate of action potentials.[1] A sensory space can be dependent of an animal's location. The term receptive field was first used by Sherrington in 1906 to describe the area of skin from which a scratch reflex could be elicited in a dog.[2] In 1938, Hartline started to apply the term to single neurons, this time from the frog retina.[1] Receptive fields have been used in modern artificial deep neural networks that work with local operations. Auditory system[edit] Somatosensory system[edit] In the somatosensory system, receptive fields are regions of the skin or of internal organs.
Semantic satiation History and research[edit] The phrase "semantic satiation" was coined by Leon Jakobovits James in his doctoral dissertation at McGill University, Montreal, Canada awarded in 1962.[1] Prior to that, the expression "verbal satiation" had been used along with terms that express the idea of mental fatigue. The dissertation listed many of the names others had used for the phenomenon: "Many other names have been used for what appears to be essentially the same process: inhibition (Herbert, 1824, in Boring, 1950), refractory phase and mental fatigue (Dodge, 1917; 1926a), lapse of meaning (Bassett and Warne, 1919), work decrement (Robinson and Bills, 1926), cortical inhibition (Pavlov, 192?) The explanation for the phenomenon was that verbal repetition repeatedly aroused a specific neural pattern in the cortex which corresponds to the meaning of the word. Applications[edit] In popular culture[edit] See also[edit] References[edit] Further reading[edit] Dodge, R.
Spinocerebellar tract The spinocerebellar tract is a nerve tract originating in the spinal cord and terminating in the same side (ipsilateral) of the cerebellum. Origins of proprioceptive information[edit] Proprioceptive information is obtained by Golgi tendon organs and muscle spindles. Golgi tendon organs consist of a fibrous capsule enclosing tendon fascicles and bare nerve endings that respond to tension in the tendon by causing action potentials in type Ib afferents. These fibers are relatively large, myelinated, and quickly conducting.Muscle spindles monitor the length within muscles and send information via faster Ia afferents. These axons are larger and faster than type Ib (from both nuclear bag fibers and nuclear chain fibers) and type II afferents (solely from nuclear chain fibers). All of these neurons are sensory (first order, or primary) and have their cell bodies in the dorsal root ganglia. Subdivisions of the tract[edit] The tract is divided into:[1][dubious ] Dorsal spinocerebellar tract[edit]
Milgram experiment The experimenter (E) orders the teacher (T), the subject of the experiment, to give what the latter believes are painful electric shocks to a learner (L), who is actually an actor and confederate. The subject believes that for each wrong answer, the learner was receiving actual electric shocks, though in reality there were no such punishments. Being separated from the subject, the confederate set up a tape recorder integrated with the electro-shock generator, which played pre-recorded sounds for each shock level.[1] The experiments began in July 1961, three months after the start of the trial of German Nazi war criminal Adolf Eichmann in Jerusalem. The experiment[edit] Milgram Experiment advertisement Three individuals were involved: the one running the experiment, the subject of the experiment (a volunteer), and a confederate pretending to be a volunteer. The subjects believed that for each wrong answer, the learner was receiving actual shocks. Results[edit] Criticism[edit] Ethics[edit]
Prey detection Prey detection is the process by which predators are able to detect and locate their prey via sensory signals. This article treats predation in its broadest sense, i.e. where one organism eats another. Evolutionary struggle and prey defenses[edit] Predators are in an evolutionary arms race with their prey, for which advantageous mutations are constantly preserved by natural selection. In turn, predators, too, are subject to such selective pressure, those most successful in locating prey passing on their genes in greater number to the next generation's gene pool. Often behavioral and passive characteristics are combined; for example, a prey animal may look similar to and behave like its hunter's own predator (see mimicry). Prey detection using different senses[edit] There are a variety of methods used to detect prey. Visual[edit] Experiments on blue jays suggest they form a search image for certain prey. Visual predators may form what is termed a search image of certain prey. Chemical[edit]
Stanford prison experiment The Stanford prison experiment (SPE) was a study of the psychological effects of becoming a prisoner or prison guard. The experiment was conducted at Stanford University from August 14–20, 1971, by a team of researchers led by psychology professor Philip Zimbardo.[1] It was funded by the US Office of Naval Research[2] and was of interest to both the US Navy and Marine Corps as an investigation into the causes of conflict between military guards and prisoners. Goals and methods[edit] Zimbardo and his team aimed to test the hypothesis that the inherent personality traits of prisoners and guards are the chief cause of abusive behavior in prison. Participants were recruited and told they would participate in a two-week prison simulation. The experiment was conducted in the basement of Jordan Hall (Stanford's psychology building). The researchers held an orientation session for guards the day before the experiment, during which they instructed them not to physically harm the prisoners. [edit]
Saddle anesthesia Medical condition Saddle anesthesia is a loss of sensation (anesthesia) restricted to the area of the buttocks, perineum and inner surfaces of the thighs. It is frequently associated with the spine-related injury cauda equina syndrome.[1] It is also seen in conus medullaris, the difference is that it is symmetrical in conus medullaris and asymmetric in cauda equina. It may also occur as a temporary side-effect of a sacral extra-dural injection:[2] See also[edit] Pudendal anesthesia ("Saddle block") References[edit] Operant conditioning Diagram of operant conditioning Operant conditioning separates itself from classical conditioning because it is highly complex, integrating positive and negative conditioning into its practices; whereas, classical conditioning focuses only on either positive or negative conditioning but not both together. Another dubbing of operant conditioning is instrumental learning. Instrumental conditioning was first discovered and published by Jerzy Konorski and was also referred to as Type II reflexes. Mechanisms of instrumental conditioning suggest that the behavior may change in form, frequency, or strength. Operant behavior operates on the environment and is maintained by its antecedents and consequences, while classical conditioning is maintained by conditioning of reflexive (reflex) behaviors, which are elicited by antecedent conditions. Historical notes[edit] Thorndike's law of effect[edit] Main article: Law of effect Skinner[edit] Main article: B. B.F. Tools and procedures[edit] See also[edit]
Prepulse inhibition Prepulse inhibition (PPI) is a neurological phenomenon in which a weaker prestimulus (prepulse) inhibits the reaction of an organism to a subsequent strong reflex-eliciting stimulus (pulse), often using the startle reflex. The stimuli are usually acoustic, but tactile stimuli (e.g. via air puffs onto the skin)[1] and light stimuli[2] are also used. When prepulse inhibition is high, the corresponding one-time startle response is reduced. The reduction of the amplitude of startle reflects the ability of the nervous system to temporarily adapt to a strong sensory stimulus when a preceding weaker signal is given to warn the organism. Deficits of prepulse inhibition manifest in the inability to filter out the unnecessary information; they have been linked to abnormalities of sensorimotor gating. PPI and startle reflex apparatus for mice Procedure[edit] PPI measurement in human. The main three parts of the procedure are prepulse, startle stimulus, and startle reflex. Major features[edit]
Macdonald triad The Macdonald triad (also known as the triad of sociopathy or the homicidal triad) is a set of three behavioral characteristics that has been suggested, if all three or any combination of two, are present together, to be predictive of or associated with, later violent tendencies, particularly with relation to serial offenses. The triad was first proposed by psychiatrist J.M. Macdonald in "The Threat to Kill", a 1963 paper in the American Journal of Psychiatry.[1] Small-scale studies conducted by psychiatrists Daniel Hellman and Nathan Blackman, and then FBI agents John E. Douglas and Robert K. Ressler along with Dr. The triad links cruelty to animals, obsession with fire setting, and persistent bedwetting past a certain age, to violent behaviors, particularly homicidal behavior and sexually predatory behavior.[5] Some other studies claim to have not found statistically significant links between the triad and violent offenders. Firesetting[edit] Cruelty to animals[edit] Enuresis[edit]
Dorsal column–medial lemniscus pathway The dorsal column–medial lemniscus pathway (DCML) (also known as the posterior column-medial lemniscus pathway, PCML) is a sensory pathway of the central nervous system that conveys sensations of fine touch, vibration, two-point discrimination, and proprioception (position) from the skin and joints. It transmits information from the body to the primary somatosensory cortex in the postcentral gyrus of the parietal lobe of the brain.[1][2] The pathway receives information from sensory receptors throughout the body, and carries this in nerve tracts in the white matter of the dorsal column of the spinal cord to the medulla, where it is continued in the medial lemniscus, on to the thalamus and relayed from there through the internal capsule and transmitted to the somatosensory cortex. The name dorsal-column medial lemniscus comes from the two structures that carry the sensory information: the dorsal columns of the spinal cord, and the medial lemniscus in the brainstem. Structure[edit]