Module 8 Flashcards
How are the sensory areas of the cortex classified?
By convention, the sensory areas of the cortex are classified into three types: primary, secondary, and association.
What defines the primary sensory cortex of a system?
The primary sensory cortex of a system is the area that receives most of its input directly from the thalamic relay nuclei of that system.
What is the secondary sensory cortex of a system?
The secondary sensory cortex comprises the areas that receive most of their input from the primary sensory cortex of that system or from other areas of secondary sensory cortex of the same system.
Define association cortex.
Association cortex is any area of cortex that receives input from more than one sensory system, with most input coming via areas of secondary sensory cortex.
What are the three major principles characterizing the interactions among sensory areas?
The three principles are hierarchical organization, functional segregation, and parallel processing.
Describe hierarchical organization in sensory systems.
Sensory systems are hierarchically organized based on the specificity and complexity of their function, with each level adding another layer of analysis before passing information up the hierarchy.
What characterizes the effects of damage to various levels of the sensory hierarchy?
The higher the level of damage, the more specific and complex the sensory deficit, with destruction of receptors resulting in a complete loss of ability to perceive in that sensory modality.
What is functional segregation?
Functional segregation refers to the organization of sensory systems into functionally distinct areas at each level of cerebral cortex, specializing in different kinds of analysis.
What is parallel processing in sensory systems?
Parallel processing refers to the simultaneous analysis of a signal in different ways by multiple parallel pathways of a neural network, indicating that sensory systems are parallel rather than serial.
What are top-down signals in sensory systems?
Top-down signals are information flows from higher to lower levels of sensory hierarchies, in addition to the more common bottom-up information flow.
What is the primary function of the auditory system?
The primary function of the auditory system is the perception of sound.
What range of molecular vibrations can humans hear?
Humans can hear molecular vibrations between about 20 and 20,000 hertz (cycles per second).
What are the three main perceptual dimensions of sound vibrations?
The amplitude, frequency, and complexity of sound vibrations are most closely linked to perceptions of loudness, pitch, and timbre, respectively.
What is Fourier analysis?
Fourier analysis is the mathematical procedure for breaking down complex waves into their component sine waves.
How is pitch perception related to the fundamental frequency of a sound?
The pitch of a sound is related to its fundamental frequency, which is the highest common divisor of the various component frequencies making up the sound.
What is the missing fundamental in pitch perception?
The missing fundamental refers to the perception of a pitch that is not directly related to the frequency of any individual component of a complex sound.
Describe the pathway of sound waves through the ear.
Sound waves travel from the outer ear down the auditory canal, causing the tympanic membrane to vibrate. These vibrations are then transferred to the ossicles of the middle ear, which in turn transmit the vibrations to the cochlea via the oval window.
What is the organ of Corti?
The organ of Corti is the auditory receptor organ located within the cochlea, composed of hair cells that respond to vibrations.
How are different frequencies represented along the basilar membrane?
Different frequencies produce maximal stimulation of hair cells at different points along the basilar membrane, with higher frequencies activating hair cells closer to the windows and lower frequencies activating hair cells at the tip of the basilar membrane.
What is tonotopic organization?
Tonotopic organization refers to the arrangement of auditory structures according to frequency, similar to retinotopic organization in the visual system.
How does the auditory pathway to the cortex differ from the visual pathway?
There is no major auditory pathway to the cortex comparable to the retina-geniculate-striate pathway in the visual system. Instead, there is a network of auditory pathways involving the cochlear nuclei, superior olives, inferior colliculi, medial geniculate nuclei, and primary auditory cortex.
Where do the axons of the auditory nerve synapse after entering the brainstem?
The axons of the auditory nerve synapse in the ipsilateral cochlear nuclei.
What is the role of the superior olives in the auditory pathway?
The superior olives combine signals from each ear and transmit them to both ipsilateral and contralateral auditory cortex.
Why are the subcortical pathways of the auditory system considered complex?
The subcortical pathways of the auditory system have many more synapses compared to other senses, which contributes to their complexity.
Where is the primary auditory cortex located in primates?
The primary auditory cortex in primates is located in the temporal lobe, hidden within the lateral fissure.
What are the three adjacent areas comprising the core region of the primary auditory cortex?
The three adjacent areas comprising the core region of the primary auditory cortex are: A1, the anterior auditory field (AAF), and the rostral field (R).
How is the primary auditory cortex organized?
The primary auditory cortex is organized in functional columns, tonotopically (by frequency), and according to the temporal components of sound, known as periodotopy.
What is the tonotopic organization of the auditory cortex?
Each area of the auditory cortex has a gradient of frequencies from low to high along its length.
What is periodotopy?
Periodotopy refers to the organization of auditory cortex according to variations in the amplitude of particular sound frequencies over time.
How has recent progress in understanding human auditory cortex been achieved?
Recent progress in understanding human auditory cortex has resulted from the convergence of functional brain-imaging studies in humans and invasive neural recording studies in monkeys.
Why has research on auditory cortex lagged behind research on visual cortex?
One major reason is a lack of clear understanding of the dimensions along which auditory cortex evaluates sound.
What is one example of an output signal from auditory cortex relevant to an animal’s current situation?
The creation of representations of auditory objects, such as converting the complex mixture of frequencies produced by a piano into a sound representation that allows recognition of the instrument.
What are the two main cortical streams of auditory analysis proposed by researchers?
The anterior auditory pathway, more involved in identifying sounds (what), and the posterior auditory pathway, more involved in locating sounds (where).
What is the traditional assumption about sensory system interactions in association cortex?
Association cortex is usually defined as areas where interactions or associations between sensory systems take place.
Where have functional brain imaging studies found evidence of sensory interactions?
Functional brain imaging studies have found evidence of sensory interactions at the lowest level of the sensory cortex hierarchy, in areas of primary sensory cortex.
What has recent research discovered about the perception of pitch in auditory cortex?
Most auditory neurons respond to changes in frequency rather than pitch; however, a small area anterior to primary auditory cortex has been identified as the likely place where frequencies of sound are converted to the perception of pitch.
What is the missing fundamental technique used in auditory research?
The missing fundamental technique involves using sound stimuli where frequency and pitch are different, revealing how auditory neurons respond to pitch.
What technique did Bendor and Wang (2005) use to identify the area responsible for perceiving pitch?
They used microelectrodes to probe primary and secondary areas of monkey auditory cortex and found a small area anterior to primary auditory cortex that responded to pitch rather than frequency.
How has research on auditory processing shifted based on recent discoveries?
Research now suggests that sensory system interaction is an early and integral part of sensory processing, occurring not only in association cortex but also at the lowest level of the sensory cortex hierarchy.
Why is the study of damage to the auditory system important?
It provides information about how the auditory system works and can serve as a source of information about the causes and treatment of clinical deafness.
What is the major permanent effect of bilateral lesions to the primary auditory cortex?
Loss of the ability to process the structural aspects of sounds, leading to a condition often referred to as “word deafness.”
What are the consequences of damage to the anterior auditory cortex pathway (the “what” pathway)?
Patients have trouble identifying sounds.
What are the consequences of damage to the posterior auditory cortex pathway (the “where” pathway)?
Patients have difficulty localizing sounds.
How prevalent is deafness as a human disability?
Deafness affects an estimated 360 million people worldwide and is one of the most prevalent human disabilities.
What are the two common classes of hearing impairments?
Conductive deafness, associated with damage to the ossicles, and nerve deafness, associated with damage to the cochlea or auditory nerve.
What is the major cause of nerve deafness?
Loss of hair cell receptors in the cochlea.
How do age-related hearing loss affect speech perception in elderly individuals?
It leads to difficulty distinguishing high frequencies, causing challenges in understanding sounds like “s,” “f,” and “t.”
What is tinnitus, and what is its association with hearing loss?
Tinnitus is ringing in the ears, often associated with hearing loss. Neuroplastic changes resulting from deafness are believed to cause tinnitus.
How do cochlear implants help individuals with nerve deafness?
Cochlear implants bypass damage to the auditory hair cells by converting sounds into electrical signals, which excite the auditory nerve.
What is the significance of early cochlear implantation after deafness onset?
The sooner a person receives a cochlear implant after becoming deaf, the more likely they are to benefit, as disuse leads to alterations of the auditory neural pathways.
An area of the cortex that receives input from multiple sensory systems and integrates sensory information is called the _______ cortex.
association
Sensation is the process of detecting the presence of stimuli, and the higher-order process called _______ allows the interpretation of sensory patterns.
perception
The simultaneous analysis of signals, also known as _______ processing, allows for information to flow through multiple pathways at the same time.
parallel
In the 1960s, the sensory organization was believed to be hierarchical, _______ _______, and serial.
functionally homogeneous,
The frequency of sound vibrations is linked to perceptions of _______.
pitch
Sound waves travel from the external environment to the outer ear, and through the auditory canal where they reach the _______ membrane.
tympanic
The three smallest bones in the human body are the malleus, the incus, and the _______.
stapes
The _______ are auditory receptors located in the cochlea on the basilar membrane, and they increase firing in axons of the auditory nerve.
hair cells
Axons from olivary neurons project to the _______ _______ via the lateral lemniscus.
inferior colliculi
The cochlea and the primary auditory cortex are both organized _______ on the bases of sound frequencies.
tonotopically
Damage to the ossicles is associated with _______ deafness, while damage to the cochlea is associated with _______ deafness.
conductive, nerve
The anterior auditory pathway is more involved in identifying sounds (what), whereas the _______ auditory pathway is more involved in locating sounds (where).
posterior
What are sensations from the body referred to as?
Somatosensations.
How many separate systems make up the somatosensory system?
Three separate but interacting systems: exteroceptive, proprioceptive, and interoceptive.
What are the divisions of the exteroceptive system?
Divisions for perceiving mechanical stimuli (touch), thermal stimuli (temperature), and nociceptive stimuli (pain).
What are the four types of cutaneous receptors?
Free nerve endings, Pacinian corpuscles, Merkel’s disks, and Ruffini endings.
What are Pacinian corpuscles sensitive to?
Sudden displacements of the skin but not to constant pressure.
How do Merkel’s disks and Ruffini endings respond to stimuli?
They adapt slowly and respond to gradual skin indentation and skin stretch, respectively.
What happens when a constant pressure is applied to the skin regarding receptor firing?
Initially, all receptors respond, but after a few hundred milliseconds, only the slowly adapting receptors remain active, leading to a change in the quality of sensation.
What is stereognosis, and how does it relate to receptor adaptation?
Stereognosis is identifying objects by touch. Receptor adaptation ensures that the pattern of stimulation continually changes during object manipulation.
How do somatosensory receptors respond to stimuli?
Stimuli deform or change the chemistry of the receptor, altering the permeability of the receptor cell membrane to various ions, resulting in a neural signal.
Initially, what was assumed about each type of receptor in the skin regarding tactile sensations?
It was assumed that each type of receptor mediated a different tactile sensation (e.g., touch, pain, heat).
What has research shown about tactile sensations and receptor mechanisms?
Each tactile sensation appears to be produced by the interaction of multiple receptor mechanisms, and each receptor mechanism contributes to multiple sensations.
How many major pathways carry somatosensory information to the human cortex?
Two major pathways: the dorsal-column medial-lemniscus system and the anterolateral system.
What type of information does the dorsal-column medial-lemniscus system tend to carry?
Information about touch and proprioception.
What type of information does the anterolateral system tend to carry?
Information about pain and temperature.
What happens to touch perception and proprioception if the dorsal-column medial-lemniscus system is lesioned?
Lesions of the dorsal-column medial-lemniscus system do not eliminate touch perception or proprioception.
What happens to pain and temperature perception if the anterolateral system is lesioned?
Lesions of the anterolateral system do not eliminate perception of pain or temperature.
How do sensory neurons of the dorsal-column medial-lemniscus system enter the spinal cord?
Via a dorsal root.
What is the role of the ventral posterior nucleus of the thalamus in the dorsal-column medial-lemniscus system?
It receives input from dorsal column nuclei neurons and projects to the primary somatosensory cortex (SI).
What is a trivia-worthy fact about dorsal column neurons originating in the toes?
Dorsal column neurons originating in the toes are the longest neurons in the human body.
How do most dorsal root neurons of the anterolateral system synapse?
Most synapse as soon as they enter the spinal cord.
What happens if both ascending somatosensory paths are completely transected by a spinal injury?
The patient can feel no body sensation from below the level of the cut.
Who mapped the primary somatosensory cortex in 1937 during neurosurgery?
Penfield and his colleagues.
What did Penfield discover about the human primary somatosensory cortex (SI)?
It is somatotopic, organized according to a map of the body surface.
What is the somatotopic map of the body surface commonly referred to as?
The somatosensory homunculus.
Where is the secondary somatosensory cortex (SII) located in relation to the primary somatosensory cortex (SI)?
Just ventral to SI in the postcentral gyrus, extending into the lateral fissure.
What body parts receive the greatest proportion of input in the somatosensory homunculus?
Hands, lips, and tongue.
What is the primary input pattern for SII?
SII receives substantial input from both sides of the body.
What evidence supports columnar organization in the primary somatosensory cortex?
Studies of single neurons found that each neuron in a particular column responds most robustly to the same type of tactile stimuli on the same part of the body.
How many functional strips compose the primary somatosensory cortex?
Four functional strips, each with a similar but separate somatotopic organization.
What are the proposed streams of analysis that proceed from SI?
A dorsal stream to posterior parietal cortex for multisensory integration and direction of attention, and a ventral stream to SII for the perception of objects’ shapes.
What were the observed deficits in patients after a unilateral excision that included SI?
Reduced ability to detect light touch and identify objects by touch (stereognosis).
Where are somatosensory signals ultimately conducted in the sensory hierarchy?
To areas of association cortex in prefrontal and posterior parietal cortex.
What type of neurons are found in posterior parietal cortex?
Bimodal neurons, which respond to activation of two different sensory systems.
What is astereognosia?
The inability to recognize objects by touch.
What is asomatognosia?
The failure to recognize parts of one’s own body.
What is contralateral neglect?
The tendency not to respond to stimuli that are contralateral to a right-hemisphere injury.
What is the rubber-hand illusion?
The feeling that an extraneous object, such as a rubber hand, is part of one’s own body.
How is the rubber-hand illusion usually induced?
By synchronously stroking both a hidden hand and a visible rubber hand.
What physiological change often accompanies the experience of the rubber-hand illusion?
A drop in temperature in the hidden hand.
Which brain regions are thought to play a role in inducing the rubber-hand illusion?
Association cortex in the posterior parietal and frontal lobes.
What role do bimodal neurons with both visual and somatosensory fields play in the rubber-hand illusion?
They are suggested to play a critical role in inducing the illusion.
What is a paradox?
A logical contradiction.
What is one paradox of pain?
Pain is adaptive; it warns us to stop engaging in potentially harmful activities or to seek treatment.
What is congenital insensitivity to pain?
A condition where individuals experience no pain due to a genetic abnormality affecting the synthesis of sodium ion channels.
Which cortical area has been most frequently linked to pain?
The anterior cingulate cortex.
What is the third paradox of pain?
Pain, the most compelling sensory experience, can be effectively suppressed by cognitive and emotional factors.
What discovery led to the identification of a descending pain-control circuit?
The discovery that electrical stimulation of the periaqueductal gray (PAG) has analgesic effects.
What are endorphins?
Endogenous opioid analgesics.
Describe the descending analgesia circuit proposed by Basbaum and Fields.
Output from the periaqueductal gray (PAG) excites serotonergic neurons in the raphé nuclei, which then project down the spinal cord to block incoming pain signals.
How have models of descending analgesia circuits evolved over time?
They have grown more complex, incorporating additional brain regions such as the anterior cingulate cortex and prefrontal cortex.
What is the thermal grid illusion?
The perception of pain resulting from placing one’s hand on a grid of metal rods that alternate between cool and warm.
What is the main role of the chemical senses in humans?
The evaluation of potential foods to encourage consumption of energy and nutrients while avoiding toxins.
What is olfaction?
Olfaction, or smell, is the response of the olfactory system to airborne chemicals drawn over receptors in the nasal passages.
What is taste?
Taste is the response of the gustatory system to chemicals in solution in the oral cavity.
What is the integrated sensory impression produced when smell and taste receptors are excited simultaneously?
Flavor.
What factors influence flavor apart from smell and taste?
Temperature, texture, appearance of food, and a person’s level of satiety.
What is the role of pheromones in regulating social interactions among many species?
Pheromones influence the physiology and behavior of conspecifics, influencing sexual and aggressive behavior.
How did Murphy and Schneider demonstrate the olfactory basis of hamsters’ aggressive and sexual behavior?
They swabbed a male intruder with the vaginal secretions of a sexually receptive female before placing it in an unfamiliar colony, altering its perception from an object of aggression to an object of sexual interest.
What is the possibility regarding humans and sexual pheromones?
There is little evidence that humans release or respond to sexual pheromones.
What are three factors contributing to the persistence of neuropathic pain?
Neuroplastic changes, epigenetic mechanisms, and involvement of specific brain structures like the anterior cingulate cortex and prefrontal cortex.
What is the role of drugs being developed in the treatment of neuropathic pain?
They aim to modify epigenetic changes associated with neuropathic pain.
Where are olfactory receptor cells located?
In the upper part of the nose, embedded in a layer of mucus-covered tissue called the olfactory mucosa.
How do olfactory receptor cells transmit signals to the brain?
Their axons pass through the cribriform plate and enter the olfactory bulbs, where they synapse on neurons that project via the olfactory tracts to the brain.
How many different kinds of olfactory receptor proteins do rats and mice have?
About 1,000.
How many different kinds of olfactory receptor proteins do humans have?
About 300.
Do olfactory receptor cells contain only one type of receptor protein molecule?
Yes, each olfactory receptor cell contains only one type of receptor protein molecule.
What is the functional principle by which olfactory receptors are distributed through the olfactory mucosa?
No such principle has been discovered; all types of olfactory receptors appear to be scattered throughout the mucosa.
What are olfactory glomeruli?
They are discrete clusters of neurons that receive input from several thousand olfactory receptor cells of the same receptor protein type.
What evidence suggests systematic topographic organization in olfactory bulbs?
Mirror symmetry between the left and right olfactory bulbs, consistent layout of glomeruli sensitive to particular odors in different species, and similar layout in related species.
What term is used to describe the poorly understood topographic organization of olfactory bulbs?
Chemotopic map.
How long does each new olfactory receptor cell survive before being replaced?
Only a few weeks.
What structures does each olfactory bulb project axons to in the medial temporal lobes?
The amygdala and the piriform cortex.
Which area of cortex is considered the primary olfactory cortex?
The piriform cortex.
Which olfactory pathway mediates the emotional response to odors?
The limbic pathway projecting diffusely to the limbic system.
Which olfactory pathway mediates the conscious perception of odors?
The thalamic-orbitofrontal pathway projecting via the medial dorsal nuclei of the thalamus to the orbitofrontal cortex.
Where are taste receptor cells found?
On the tongue and throughout the gastrointestinal tract.
What are taste buds?
Clusters of 50 to 100 taste receptor cells often located around small protuberances called papillae.
How many types of receptor cells compose each taste bud?
Three types: cells that detect bitter, sweet, and umami; cells that detect sour; and cells that detect salty.
How do taste receptor cells communicate with neurons carrying signals away from taste buds?
Only one of the receptor cells, the presynaptic cell, synapses onto the neuron carrying signals away from the bud, while communication among the other cells occurs via gap junctions.
How long do gustatory receptor cells survive before being replaced?
Only a few weeks.
What are the five primary tastes that have been most studied?
Sweet, sour, bitter, salty, and umami
How is taste transduction for sweet, umami, and bitter mediated?
By metabotropic receptors.
How is taste transduction for salty and sour mediated?
By ionotropic receptors.
Where do gustatory afferents terminate in the brain?
In the solitary nucleus of the medulla, where they synapse on neurons that project to the ventral posterior nucleus of the thalamus.
Where is the primary gustatory cortex located?
In the insula, an area of cortex hidden in the lateral fissure.
What is the secondary gustatory cortex?
It is located in the orbitofrontal cortex.
Are the projections of the gustatory system primarily ipsilateral or contralateral?
Primarily ipsilateral.
What is anosmia?
The inability to smell.
What is ageusia?
The inability to taste.
What neurological cause of anosmia is most common?
A blow to the head causing displacement of the brain within the skull and shearing of the olfactory nerves passing through the cribriform plate.
After damage to the ear on the same side of the body, where might partial ageusia be observed?
In the anterior two-thirds of the tongue on the same side due to the passage of gustatory information through the middle ear via the branch of the facial nerve (VII).
Information from the receptors in the muscles, joints, and balance organs about the position of the body is monitored by the _______ system.
proprioceptive
The largest and deepest receptors of the skin that respond to sudden displacements of the skin but not to constant pressure are called _______.
Pacinian corpuscles
Some skin receptors such as the Ruffini endings and _______ adapt slowly, allowing the static properties of tactile stimuli to become unnoticeable.
Merkel’s disks,
Most of the output of the secondary somatosensory cortex goes to the association cortex of the _______ lobe and participates in the perception of
objects’ shapes.
posterior parietal
A rare neuropsychological condition known as _______
affects the ability to recognize one’s own body parts.
asomatognosia
Some of the areas of the brain implicated in pain
perception are the thalamus, SI and SII, the anterior
cingulate gyrus, and the _______.
insula
Sexual and aggressive behavior in animals, such as
hamsters, are controlled by _______.
pheromones
Clusters of neurons that lie near the surface of the
olfactory bulb are called olfactory _______.
glomeruli
The emotional response to odors is thought to be
mediated by the _______ system.
limbic
Gustatory signals leave the back of the tongue reaching the solitary nucleus of the medulla and from there to the thalamus. The final destination is the primary gustatory cortex located in the _______.
insula
How does prior knowledge affect visual perception?
For example, shadows usually appear beneath objects due to our knowledge that the sun is the primary source of light.
What effect does prior knowledge about the temporal order of sensory events have on perception?
It influences how we perceive sequences of events, such as the order of colored lights at a stoplight.
According to some researchers, what are humans considered in terms of perception?
“Prediction machines” that actively construct models of the world based on prior experiences and sensory information.
What consumes a large proportion of the brain’s energy, according to research?
Ongoing perceptual decision making
What are bistable figures, and what do they illustrate?
Bistable figures are visual stimuli that can be interpreted in two different ways. They illustrate perceptual decision making at work.
What are phantom percepts?
Phantom percepts are products of perception that occur in the absence of sensory input.
Give an example of phantom percepts.
Phantom limbs, where amputees perceive the presence of their missing limb long after it has been lost to injury or amputation.
What is Charles Bonnet Syndrome?
It is a condition where individuals deprived of visual input later in life experience rich and complex hallucinations, such as people’s faces or complex landscapes.
What brain areas are implicated in perceptual decision making?
The dorsolateral prefrontal cortex and the posterior parietal cortex.
What is interesting about the brain structures involved in perceptual decision making?
They are also involved in the decision to initiate physical movement.
What phenomenon illustrates ongoing perceptual decision making in the absence of sensory input?
Bistable figures, where the interpretation of visual stimuli can switch back and forth even without changes in the stimuli themselves.
What is the binding problem in sensory perception?
The binding problem refers to how the brain combines individual sensory attributes to produce integrated perceptions.
What are two proposed solutions to the binding problem?
One proposed solution is a single area at the top of the sensory hierarchy responsible for integrating sensory information. Another solution suggests that binding emerges from interactions at each level of the cortical hierarchy.
What structure in the brain has received attention as a potential location for binding sensory information?
The claustrum, a structure made up of a fine sheet of neurons located just underneath the cortex towards the middle of the brain.
How does selective attention improve perception?
It improves the perception of focused stimuli while interfering with the perception of stimuli not in focus.
What are the two ways attention can be focused?
Attention can be focused by internal cognitive processes (endogenous attention) or by external events (exogenous attention).
How is endogenous attention thought to be mediated?
Endogenous attention is thought to be mediated by top-down neural mechanisms, from higher to lower levels.
How is exogenous attention thought to be mediated?
Exogenous attention is thought to be mediated by bottom-up neural mechanisms, from lower to higher levels.
What is the cocktail-party phenomenon?
The cocktail-party phenomenon refers to the ability to focus on one conversation while being aware of other conversations, but suddenly noticing when one’s name is mentioned in another conversation.
How does the cocktail-party phenomenon illustrate selective attention?
It demonstrates the brain’s ability to block out stimuli except those of particular interest while still unconsciously monitoring other stimuli for relevance.
How can visual attention be shifted without changing the direction of visual focus?
Visual attention can be shifted independently of eye movements, allowing one to focus on a specific aspect of the visual scene while still observing peripheral information.
What is change blindness?
Change blindness is the phenomenon where individuals fail to notice changes in a scene, typically due to limited attentional focus.
Why does change blindness occur?
Change blindness occurs because individuals have no memory for parts of a scene that are not the focus of their attention.
Where do top-down attentional influences on sensory systems originate?
Top-down attentional influences on sensory systems are believed to originate from both the prefrontal cortex and the posterior parietal cortex.
What did Moran and Desimone’s (1985) experiment demonstrate?
Moran and Desimone’s experiment demonstrated that attention can modulate neural activity in the visual system, with neurons responding more strongly to attended stimuli.
How does selective attention work at the neural level?
Selective attention works by strengthening neural responses to attended stimuli while weakening responses to others, known as a push-pull mechanism.
What is covert attention?
Covert attention is the process of attending to a sensory stimulus without moving one’s gaze.
What brain area has been implicated in mediating shifts in visual attention?
The frontal eye field, located on the ventral surface of the frontal cortex, is implicated in mediating shifts in visual attention.
What disorder is associated with difficulty in attending visually to more than one object at a time?
Simultanagnosia is associated with difficulty in attending visually to more than one object at a time.
What brain region is typically associated with simultanagnosia?
Simultanagnosia is usually associated with bilateral damage to the posterior parietal cortex.
What role does sensory experience during early postnatal life play in neural circuit maturation?
Sensory experience during early postnatal life is crucial for refining and maturing neural circuits across sensory systems.
What is tonotopy?
Tonotopy refers to the spatial organization of neurons in the auditory system according to their preferred sound frequencies.
How was the role of auditory experience in the development of the tonotopic map in A1 studied?
The role of auditory experience was studied by altering the acoustic environment of young animals and observing changes in the tonotopic map of the primary auditory cortex (A1).
Describe the experimental setup in Study 1 conducted by Zhang, Bao, & Merzenich (2001).
Rats were exposed to continuous tones of specific frequencies (e.g., 4 kHz or 19 kHz) from postnatal day 9 to day 28. The tonotopic organization of A1 was then examined in adulthood.
What did Zhang and colleagues observe regarding the tonotopic map of A1 in rats exposed to specific frequencies during development?
Rats exposed to specific frequencies during development exhibited an enlargement of the corresponding frequency area in the tonotopic map of A1.
Did the tonotopic map of adult rats change when exposed to specific tones?
No, the tonotopic map of adult rats did not change when exposed to specific tones, as observed in mothers who were also exposed to the tones but showed no changes in their A1 maps.
What is the significance of the findings from Zhang and colleagues’ study regarding the role of auditory experience in A1 development?
The study highlights the critical role of early auditory experience in shaping the tonotopic map of A1, demonstrating that the acoustic environment during development influences neural circuit organization.
What do the experiments by Zhang and colleagues reveal about the development of the mammalian A1?
The experiments show that the developing brain becomes tuned to available sensory inputs, and the tonotopic map development in the A1 is strongly influenced by acoustic experience during early postnatal development.
How did Chang and Merzenich study the effects of depriving the developing auditory system of patterned acoustic inputs?
They exposed rat pups to continuous white noise throughout postnatal development to block patterned acoustic inputs and observed the resulting effects on the development of A1 tonotopy.
What are patterned inputs in the context of auditory development?
Patterned inputs refer to sounds with specific temporal changes in frequencies, amplitude, and complexity over time, such as speech, music, or natural environmental sounds.
Describe the consequences of continuous white noise exposure on the development of A1 tonotopy in rats.
Continuous white noise exposure prevented the normal development of A1 tonotopy, resulting in an immature tonotopic organization similar to that of juvenile rats.
How does sensory experience during early postnatal life influence sensory system development?
Sensory experience during early postnatal life guides the maturation and refinement of sensory systems, with neurons becoming tuned to prevalent and behaviorally relevant sensory inputs.
What is the significance of the findings regarding the role of acoustic experience in A1 development?
The findings underscore the importance of early auditory experience in shaping A1 tonotopy and highlight the impact of sensory deprivation on cortical development.
How does the development of A1 tonotopy compare to the influence of postnatal visual experience on ocular dominance columns in V1?
Similar to how postnatal visual experience influences ocular dominance columns in V1, the development of A1 tonotopy is guided by early auditory experience.
What is the role of acoustic experience in postnatal A1 development?
Acoustic experience guides the maturation of A1 tonotopy, with neurons becoming tuned to sounds present in the environment during sensitive periods of neural plasticity.
How does sensory deprivation during early postnatal development affect sensory system development?
Deprivation of patterned sensory inputs disrupts typical sensory experience-dependent cortical development, as seen in the auditory system with the absence of A1 tonotopy development under continuous white noise exposure.
Which of the following refers to a spatial arrangement in which neurons are organized within a region as a function of the frequency to which they maximally respond?
tonotopy
characteristic frequency
somatotopy
retinotopy
tonotopy
Why might a cochlear implant be less effective for restoring frequency discrimination when it is implanted in a teenager or adult compared to a child?
brain plasticity increases as the brain develops and matures
the sensitive period for A1 development has not yet opened
the sensitive period for A1 development has already closed
hair cells within the cochlea become damaged as an individual ages
the sensitive period for A1 development has already closed
What would be the most detrimental to the development of A1 in a young child?
traffic noise outside the window
a white noise machine to calm the child
music
adults talking
a white noise machine to calm the child
What is cross modal perception?
Cross modal perception refers to the integration of signals from multiple sensory modalities to produce a complete and coherent representation of complex stimuli.
How does the activation of taste buds relate to the perception of food?
The perception of food is not solely determined by taste bud activation but also by stimulation of olfactory receptors, tactile receptors, auditory stimuli (e.g., crunching sounds), and visual cues.
What brain region is believed to be important for sensory integration across modalities?
The angular gyrus, located at the junction between the temporal, visual, and parietal lobes, is crucial for sensory integration across modalities and cross modal perception.
What functions is the angular gyrus involved in?
The angular gyrus is involved in attention, cognition, memory, language processing (e.g., reading, writing, interpreting word meaning), and higher-order sensory processing.
What deficits are associated with damage to the angular gyrus?
Damage to the angular gyrus is associated with deficits such as alexia and agraphia (inabilities to recognize and write words), acalculia (an inability to perform basic mathematical tasks), difficulty distinguishing left and right sides of the body, memory impairments, and mood changes.
What is synesthesia?
Synesthesia is a perceptual phenomenon where stimulation of one sensory modality leads to an involuntary experience in another sensory modality.
What is the most well-researched form of synesthesia?
The most well-researched form of synesthesia is grapheme-colour synesthesia, where letters or numbers consistently elicit experiences of particular colors.
Define “inducer” and “concurrent” in the context of synesthesia.
In synesthesia, the inducer is the sensory stimulus that elicits the synesthetic experience, while the concurrent is the synesthetic sensory experience itself.
Is synesthesia typically unidirectional or bidirectional?
Synesthesia is typically unidirectional, meaning the synesthete experiences a sensation in response to a stimulus but not necessarily vice versa.
What is the bouba/kiki effect?
The bouba/kiki effect is a phenomenon where people tend to associate rounded shapes with the word “bouba” and angular shapes with the word “kiki.”
How does the bouba/kiki effect relate to synesthesia?
The bouba/kiki effect is believed to result from similar sensory integration processes as those underlying synesthesia.
What hypothesis suggests the cause of synesthesia?
According to the cross-talk hypothesis, synesthesia arises from abnormal connectivity between cortical regions involved in sensory processing.
What percentage of synesthetes have a first-degree relative with the condition?
Approximately 40% of synesthetes have a first-degree relative who also has the condition.
What is the suggested genetic basis for synesthesia?
While the genetic basis of synesthesia is not fully understood, it is believed to have a genetic component, with multiple gene variants linked to the condition.
Are synesthesia-like mappings present in most neurologically healthy individuals?
Yes, synesthesia-like mappings likely exist in most neurologically healthy individuals, as seen in phenomena like the bouba/kiki effect.
The angular gyrus is located at the junction of which lobes?
frontal, parietal, and temporal
frontal, parietal, and occipital
parietal, temporal, and occipital
frontal and parietal
parietal, temporal, and occipital
Which of the following tasks would you NOT expect to be difficult for a person who has suffered damage to her angular gyrus?
writing a sentence about herself
interpreting a written passage about the brain
adding three numbers together
differentiating between two colours
differentiating between two colours
The mapping of speech sounds onto visual objects (the bouba/kiki effect) was first observed by:
Vilayanur Ramachandran
Edward Hubbard
Wolfgang Köhler
Jaimie Ward
Wolfgang Köhler
The most well-researched form of synesthesia involves the involuntary perception of _______________ in response to _______________.
colour; letters and/or numbers
scents; letters and/or numbers
colour; timbre of instruments
scents; words
colour; letters and/or numbers
Is pain perception strongly influenced by top-down processes?
Yes, pain perception is strongly influenced by top-down processes such as mood, emotional state, attention, cognitive appraisal, and expectations.
What is the placebo effect?
The placebo effect refers to a beneficial outcome of a treatment that is attributed to a patient’s belief in the treatment’s effectiveness rather than the treatment itself.
How are placebos commonly used in research settings?
Placebos are used in research settings to account for factors unrelated to the treatment being studied but may still have therapeutic effects. They help determine the true efficacy of a treatment.
What brain regions are involved in the subjective control of pain?
Subdivisions of the prefrontal cortex and the anterior cingulate cortex are important contributors to the subjective control of pain.
Which brain region regulates thoughts, affect, and behaviors related to pain?
The prefrontal cortex regulates thoughts, affect, and behaviors related to pain.
What role does the anterior cingulate cortex play in pain perception?
The anterior cingulate cortex is involved in directing attention towards pain and processing its unpleasantness.
What is placebo analgesia?
Placebo analgesia refers to pain reduction induced by the belief in the effectiveness of a treatment, often involving decreased activity in the anterior cingulate cortex and increased activity in the prefrontal cortex.
What neuromodulatory systems are involved in placebo-induced pain reduction?
The endogenous opioid and endocannabinoid systems are important modulators in placebo-induced pain reduction.
How can the placebo effect be blocked?
The placebo effect can be blocked by administering an opioid receptor antagonist, indicating that the effect is mediated by the release of endogenous opioids.
Do cognition and learning processes contribute to the placebo effect?
Yes, cognition and learning processes contribute to the placebo effect, as demonstrated by the ability to block the effect with an opioid receptor antagonist and the dependence of the effect on expectations about the placebo.
How does the placebo effect reduce pain?
The placebo effect reduces pain through increased activity in a subregion of the prefrontal cortex (PFC) responsible for inhibiting negative thoughts and affect related to the pain.
Increased PFC activity reduces activity in a subregion of the anterior cingulate cortex (ACC) involved in the subjective experience of the unpleasantness of the pain.
The final outcome of the cascade of effects is the reduction of pain transmission and perception.
Which of the following cortical areas is primarily involved in processing discriminative elements of pain?
a). cingulate cortex
b). primary somatosensory cortex
c). frontal cortex
d). both a and b
b). primary somatosensory cortex
Which of the following brain regions is/are implicated in placebo-analgesia?
a). primary sensory cortex
b). anterior cingulate cortex
c). prefrontal cortex
d). both b and c
d). both b and c
The study conducted by Lieberman and colleagues involved patients suffering from:
cancer
multiple sclerosis
fibromyalgia
irritable bowel disease
irritable bowel disease
Based on the study conducted by Lieberman and colleagues, for pain control in irritable bowel disease, you are best off receiving ____________ because _____________.
a standard analgesic / they are the most effective pain-reducing treatments available
no drug treatment / there are no effective drugs available to control pain
a placebo / they can be as effective as standard analgesics
a placebo / because they are less effective, but have no problematic side-effects
a placebo / they can be as effective as standard analgesics
