FINAL EXAM 2NF3

calcarine sulcus

contains much of the primary visual cortex (V1), and divides the upper and lower halves of the visual world

lingual gyri

includes part of visual cortical regions V2 and VP (closet to the occipital lobe)

Fusiform gyri

includes part of the visual cortical region V4, involved in complex processing

striate cortex

the fourth cortical layer of the visual cortex that has four distinct layers and appears as a thick stripe

cytochrome oxidase

an enzyme crucial in making energy available to cells

V1 (striate cortex)

is the first processing level in the hierarchy, receiving the largest input from the lateral geniculate nucleus of the thalamus and projecting to all other extrastriate cortex occipital regions for higher order processing (recognition of shapes, motion, and colour

V2

the second processing level, also projects to all other occipital regions

after V2

three parallel pathways emerge en route to the parietal cortex, output to the parietal lobe through the dorsal stream, output to the inferior temporal lobe via the ventral stream, and output to the STS stream

area V4

considered a colour area, cells are not solely responsible for colour, some cells respond to both colour and form, injury to this area results in loss of colour cognition

area V5

also known as middle temporal/area MT, specialized to detect motion

input from area V1 and V2 to V3

concerns dynamic form — the shape of objects in motion

vision for action

visual processing required to direct specific movements such as guiding, grasping, movement of the eyes, head, and body; sensitive to the targets movement (think reflex, how you’re interacting with your environment)

action for vision

a more “top-down” process, when the viewer actively searches for only part of the target and attends to it selectively, eye movements and selective attention

egocentric space

central to controlling your actions towards objects, relative to an individual

allocentric space

properites that are necessary for constructing a memory of spatial location, spatial coding is its dependence on the identity of particular features of the world; relative to others

polysensory neurons

neurons responsive to both visual and auditory or both visual and somatosensory input

monocular blindness

caused by the destruction of the retina or optic nerve produces loss of sight in the entirety of that particular eye

bitemporal hemianopia

a lesion of the medial region of the medial optic chiasm severs the crossing fibres (typically due to a tumour in the pituitary gland), creating a loss of vision in both temporal fields

nasal hemianopia

a lesion of the lateral chiasm results in the loss of vision is one nasal field

homonymous hemianopia

complete cut of the optic tract, lateral geniculate body, or area V1, results in blindness of one entire visual field, visual defect is present in both eyes

macular sparing

helps to differentiate lesions of the optic tract or thalamus from cortical lesions because this occurs only after unilateral lesions (usually large) to the visual cortex; lesions of the occipital lobe often spare the central region of the visual field (double vascular supply from the medial and cerebral artery

quadrantanopia

complete loss of vision in one quarter of the fovea, typically due to visual cortex lesions near the calcarine sulcus

hemianopia

complete loss of vision in one half of the fovea

scotomas

small blind spots in the visual field, caused by small occipital lobe lesions, people are often unaware of

nystagmus

constant tiny involuntary eye movements

perimetry

a standardized method in which a subject fixates on the black dot in the centre of a large white hemisphere, the task is to indicate when the light is visible

blindsight

being able to detect when a stimulus is present in a blind spot and where it entered but not perceive its contents; can only occur through damage to V1

angioma

a collection of abnormal blood vessels that results in abnormal blood flow; a type of benign tumour

visual agnosia

an inability to combine individual visual impressions into complete patterns — unable to recognize objects or their pictorial representations, and unable to draw or copy them

optic ataxia

a deficit in visually guided hand movements, such as reaching, that cannot be ascribed to motor, somatosensory, or visual field or acuity deficits

apperceptive agnosia

any failure to recognize objects in which basic visual functions (acuity, colour, motion) are preserved; an inability to percept a structure of an object or objects; due to gross bilateral damage to the occipital cortex

simultagnosia

patients can perceive the basic shape of an object, but are unable to perceive more than one at a time

associative agnosia

the inability to recognize an object despite its apparent perception; an agnostic can copy a drawing quite well but cannot identify it; results from lesions to the anterior temporal lobes

prosopagnosia

the inability to recognize faces, including their own as seen in a mirror or a photograph; they can recognize people by face information (moustache, hairdo, etc.); due to bilateral damage in the temporal cortex

alexia

the inability to read and construct wholes from parts; most likely resulting from damage to left fusiform and lingual areas

topographic disorganization

the inability to find ones way around familiar places; usually also have deficits in facial recognition; likely caused by damage to occipiotemporal, medial fusiform and lingual areas

parietal lobe

processes and integrates somatosensory and visual information, especially in regard to controlling movement

Area PE connections

plays a role in guiding movement by providing information about limb position; basically somatosensory, receiving most of its inputs from the primary somatosensory cortex, cortical outputs are to primary motor cortex, supplementary motor, premotor regions, and area PF

Area PF connections

efferent connections are similar to PE’s and presumably elaborate similar information for the motor systems; heavy input from somatosensory cortex from PE, motor, premotor cortex, and small visual input from PG

area PG connections

apart of the dorsal stream, aka “parieto-temporo-occipital crossroads” receiving complex connections such as visual, somesthetic, proprioceptive, auditory, vestibular, ocularmotor, and cingulate

parieto-premotor pathway

one of the three functional pathways leaving the posterior parietal region, proposed as the principal “how” pathway”

parieto-prefrontal pathway

one of the three functional pathways leaving the posterior parietal region, proposed to have visuosaptial functions, especially related to visuospatial working memory

perieto-medial temporal pathway

one of the three functional pathways leaving the posterior parietal region, flow directly to the hippocampus and more, proposed to have a role in spatial navigation

anterior parietal zone

processes somatic sensations and perceptions

posterior parietal zone

specializes primarily in integrating sensory input from the somatic and visual regions, mostly for controlling movements such as reaching, grasping, and whole body movements in space

viewer-centered system

the objects location, its local orientation and motion must be determined relative to the viewer

object-centred system

must be concerned with with such properties as the objects size, shape, colour, and relative location so that the objects are recognized when encountered in different contexts and vantage points

posterior parietal cells

receive combinations of sensory, motivational, and related motor inputs; their discharge is enhanced when an animal attends to a target or moves towards it. They are well suited for transforming requisite sensory information into commands for directing attention

sensorimotor transformation

perceptions of our body are constantly updating so that we can make future movements smoothly, cells in the posterior parietal cortex produces movement and sensory related singals to make these calculations

acalculia

the inability to preform mathematical operations because of the tasks spatial nature

temporoparietal junction

a region where the temporal and parietal lobe meet at the end of the sylvian fissure

stereognosis

deficits in tactile perception

afferent paresis

loss of kinesthetic feedback that results in clumsy finger movements from lesions to the post central gyrus (areas 3-1-2)

astereognosis

the inability to recognize the nature of an object by touch

simultaneous extinction

the inability to perceive many sensory stimuli at the same time, failure to report one stimulus is most commonly associated with damage to the secondary somatic cortex (areas PE and PF)

blind touch/numb touch

having a tactile analogue of blindsight from large lesions in areas PE, PF, and some of PG; complete anesthesia on the right side of her body so severe that it was likely one could cut or burn themselves without being aware of it

asomatgnosia

loss of knowledge or sense of one’s own body and bodily condition

anosognosia

a variety of asomatognosia, unawareness of denial of illness

anosodiaphoria

a variety of asomatognosia, indifference to illness

autopagnosia

a variety of asomatognosia, the inability to localize and name body parts

asymbolia for pain

a variety of asomatognosia, absence of typical responses to pain such as reflexive withdrawal from a painful stimulus

finger agnosia

a type of autopagnosia, when a person is unable to point to the various fingers of either hand or to show them to an examiner

Bálints syndrome

a rare condition where the patient had a full visual field and could recognize, use, and name object but could not fixate on specific visual stimuli, had simultagnosia, and optic ataxia

contralateral neglect

occurs in the side of the body opposite a lesion, ignoring tactile sensation on that side of the body, appeared unaware of symptoms; lesions most often in the right inferior parietal lobe (right intraparietal sulcus); patients draw on only one side of the page

allesthesia

the first recovery stage for neglect, characterized as a persons beginning to repsond to stimuli on the neglected side as if it were on the unlesioned side

agraphia

the inability to write

Gertmann syndrome

deficits subsequent to a left parietal stroke; finger agnosia, right-left confusion, agraphia, and acalulia

symptoms typical of left parietal lesions

disturbed language function, apraxia, dyscalculia, recall issues, right-left discrimination, right hemianopia

apraxia

a movemnet disorder in which the loss of skilled movement is NOT caused by weakness, inability to move, abnormal muscle tone or posture, intellectual deterioration, poor comprehension, or other disorders of movement such as tremours

idemotor apraxia

patients are unable to copy movements or to make gestures (like waving hello)

constructional apraxia

a visuomotor disorder, spatial organization is disturbed; patients cannot assemble a puzzle, build a tree house, draw a picture, or copy a series of facial movements

drawing deficits

can arise in subsequent damage to either hemisphere but is beleieved to be most severe after damage to the right parietal region

disengagement

allows attention to shift from one stimulus to another

superior temporal sulcus (STS)

separates the superior and middle temporal gyri and houses significant amounts of neocortex, functions include theory of mind, biological motion, faces, voices, and language

medial temporal region (limbic cortex)

includes the amygdala and the adjacent cortex, the hippocampus and surrounding cortex, and the fusiform gyrus

temporal-parietal junction (TPJ)

the cortical region lying along the boundary of the temporal and parietal lobes, roughly at the end of the sylvian fissure, consistently shown to be active in attention, memory, language, and social processing; proposed to be central in decision making in a social context

preforant pathway

when disrupted results in major dysfunction of hippocampal activity

basic functions of the temporal cortex

processing auditory input, visual object recognition, long-term storage of sensory input (memories)

cross-modal matching

the process of matching visual and auditory information, depending on the superior temporal sulcus

biological motion

movements that have a particular relevance to a species; human are able to use their bodies in a social context

social cognition

a theory of mind that allow us to develop hypotheses about other people’s intentions

formmants

specific restricted frequency ranges where speech sounds come from

loudness

related to the intensity of a sound measured in decibels, the subjective magnitude of an auditory sensation judged by a given person as “very loud”, “soft spoken”, “very quiet”

timbre

refers to the distinct character of a sound, the quality that sets it apart from sounds at a similar pitch and loudness; like being able to tell the difference between a violin and trombone playing the same note at the same loudness

pitch

refers to the position of a sound in a musical scale, judged by the listener. clearly related to frequency, the vibration rate of a sound wave, contribute to the tone of the voice

prosody

tone of voice

overtones/partials

frequencies above the fundamental frequency

fundamental frequency

the lowest component of a note in a sound pattern, 264 Hz or middle C

harmonics

overtones that are multiples of the fundamental

periodicity pitch

a phenomenon when the overtones are suffient enough to determine the pitch of the fundamental frequency via removal of the fundamental frequency via electronic filters

auditory hallucinations

when a patient hears fully formed verbal passages that appear to be coming from an external source but are not actually there; they tend to be hostile and paranoid

spectral sensitivity

concerned with distinguishing frequency differences

amusia

affects about 4% of people, an abnormality in one’s neural networks for music that makes them tone deaf

semantic categories

hierarchies of meaning in which a single word may belong to several categories simultaneously

primary motor cortex (M1)

area 4, specifies elementary movements (mouth and limbs), controls movement force and direction; cells project to subcortical motor structures such as the basal ganglia, red nucleus, and spinal cord

Premotor cortex (PM)

areas 6, 8, and 44; three other major sections: dorsal (PMd), ventral (PMv), and broca’s area, can influence limb and eye movements indirectly or directly

dorsal PMd

is active for choosing movements from its movement lexicon

ventral PMv

contains mirror neurons that recognize others movements and select similar or different actions

prefrontal cortex (PFC)

receives projections from the dorsomedial nucleus of the thalamus, input from the mesolimbic dopamine cells in the tegmentum; playing an important role in how neurons react to stimuli and contributes to emotional states

dorsolateral prefrontal cortex (DLPFC)

areas 9 and 46, extensive connections to areas similar to that of the posterior parietal cortex, key functions lie in its relation to the posterior parietal cortex