[PSYC 3723] Term Test #2

Parietal Cortex

• lies between the frontal and occipital lobes, underlying the parietal bone at the roof of the skull

• Projections from the primary somatosensory cortex (area 3- 1-2) extend to secondary somatosensory area (area 5), which has a tactile recognition function

• The connections to the motor cortex are important for providing sensory information about limb position and movement

anterior parietal cortex

• includes the postcentral gyrus (areas 3-1-2) and region area 43

• makes pretty straightforward connections

posterior parietal cortex

• made up of two subregions:
  1. superior parietal lobule (includes the dorsal lateral regions of area 7 and area 5)
  2. inferior parietal lobule (encompasses the supramarginal gyrus (area 40) and the angular gyrus (area 39))

• makes a LOT of connections

• also plays a significant role in mental imagery, especially related to both object rotation and navigation through space

precuneus region

• The least understood region of the parietal cortex is the _____ which lies on the medial surface

• MRI studies have suggested that it may have up to three subsections within it and that it may play a role in:

  • sensorimotor function

  • cognitive functioning

  • vision-related functions

parieto–premotor pathway

is proposed as the principal “how” pathway

parieto–prefrontal pathway

is proposed to have visuospatial functions

parieto–medial-temporal pathway

is proposed to have a role in spatial recognition and spatial navigation

anterior zone

processes somatic sensations and perceptions.

posterior zone

specializes primarily in integrating sensory input from the somatic and visual regions and controlling movement — eye movements, reaching and grasping, and whole-body movements in space

Movement Guidance

• posterior parietal lobe has a role in visuomotor guidance

• As we execute motor movements, we are concurrently receiving sensory information about the execution of the movements, and in turn, re-calibrating and adjusting

• Research has shown that when a monkey manipulates an object, cells in the parietal lobe respond to the object’s features such as:

  • Shifts in weight as we interact with it

  • New visual vantage points as we interact with it

  • New orientation of the object as we interact with it

  • Movements of the object itself

Sensorimotor transformation

• when we move toward objects, we must integrate movements of various body parts w/ sensory feedback of what movements are actually being made, and the plans to make the movements

• as we move, the locations of our body parts change, and perceptions of our body must constantly be updated so that we can make future movements smoothly

• these neutral calculations are called _____

• cells in the posterior parietal cortex produce both the movement-related and the sensory-related signals to make them

Spatial navigation

• when we travel within our environment, we can take the correct route subconsciously, making the correct turns at choice points until we reach our destination

• “cognitive spatial map” in our brains, a mental list of what we do at each spatial location “route knowledge”

• combination of various regions helping to make specific visually guided movements at specific locations in our journey

Object recognition

• visuomotor control must be viewer centered; that is, the object’s location and its local orientation and motion must be determined relative to the viewer

• object-centred system must be concerned with such properties as objects’ sizes, shapes, colours, and relative locations so that the objects are recognized

• To search for different birds, you need to be aware of the specific colors, shapes, and sizes of birds that you encounter. This process of _____ is the function of the ventral visual pathway in the temporal lobe.

acalculia

inability to perform mathematical operations because of the task’s spatial nature

postcentral gyrus

somatosensory symptoms association with damage to the ____________ — that is, the anterior parietal cortex and the adjacent cortex in the posterior parietal cortex

somatosensory threshold

• damage to the postcentral gyrus is typically associated with marked changes in _____ for detecting objects through touch

• lesions of the postcentral gyrus produce abnormally high sensory thresholds, impaired position sense, and deficits in tactile perception

astereognosis

• inability to recognize the nature of an object by touch

• objects are placed on the palms of blindfolded participants that are told to handle shapes

• task is to match the original shape to one of the several alternatives solely on the basis of tactile information

simultaneous extinction

• inability to detect a sensory event when it is paired with an identical one on the opposite side of the body or visual space

• it is also when a person is unable to report the presence of one stimulus when presented simultaneously with another

numb touch

• a tactile case similar to blindsight

• existence of 2 tactile systems: one specialized for detection and the other for localization

asomatognosia

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

contralateral neglect

• a perceptual disorder specific to lesions in the right parietal lobe

• NEGLECTING/IGNORING THE TACTILE SENSATION ON THE LEFT SIDE OF THE BODY AND THE WORLD

  • ex: ice cream → cream
    football → ball
    while dressing, he did not attempt to dress his left side of his clothing
    

apraxia

movement disorder characterized by the loss of skilled movement

ideomotor apraxia

• patients are unable to copy movements/make gestures

• patients w/ left posterior parietal lesions often present _____

  • right parietal lesions perform it normally

• deficits can be quantified by asking them to copy a series of arm/facial movements

constructional apraxia

• spatial organization is disturbed

• ex: cannot assemble a puzzle, build a tree house, draw, copy facial movements

• can develop after an injury to either parietal lobe

temporal lobe; amygdala; hippocampal

• comprise all of the tissue that lies below the lateral (Sylvian) fissure and anterior to the occipital cortex

• Subcortical temporal-lobe structures include the _____ and the _____ formation

temporal-lobe gyri; medial temporal lobe

______ visible in a medial view

_____ includes structures such as the pyriform cortex, the uncus, and extensions of the hippocampal formation

lateral (Sylvian) fissure

contains tissue forming the insula, which includes the gustatory cortex as well as the auditory association cortex.

superior temporal sulcus

• changeable aspects of faces, perception of eye gaze, expression, lip movement

  • Neutral

  • Content / Posing

  • Gaze forward

• responsible for detecting biological motion

  • ex: our eyes, faces, mouths, hands, and bodies make movements that can have social meanings

• play a role in categorizing stimuli

• analyzing actual or implied body movements that provide socially relevant information

• STS cells are maximally sensitive to bodies moving in a particular direction, another characteristic biological motion

• separates the superior and middle temporal gyri and houses a significant amount of cortex as well

sensory pathway

• allows for stimulus recognition

• The visual projections form the ventral visual stream, and auditory projections both form parallel ventral streams of processing.

• Auditory and visual information progress ventrally from the primary regions toward the temporal pole en route to the medial temporal regions.
  

dorsal auditory pathway

• concerned with directing movements with respect to auditory information

• Projecting from the auditory areas to the posterior parietal cortex, this pathway likely plays a role in detecting the spatial location of auditory inputs

polymodal pathway

• probably underlies stimulus categorization.

• responding to several different forms of sensory stimulation

• This series of parallel projections from the visual and auditory association areas converge in the _____ regions of the superior temporal sulcus (STS)

  • Auditory, visual, and somatic outputs go to the _____ regions of the STS.

medial temporal projection

• is crucial to long-term memory.

• The projection from the auditory and visual association areas into the _____, or limbic, regions goes to the hippocampal formation and/or the amygdala

frontal-lobe projection

• is necessary for various aspects of movement control, short-term memory, and cognition

• This series of parallel projections reaches from the temporal association areas to the frontal lobe

Olfactory projections

• are related to odour perception and memory

• to the pyriform cortex en route to the hippocampus links the odour to the visual and auditory memories

Developing object categories

• You also need to categorize the birds quickly because they often fly away. You do so by using information that varies in perspective from sighting to sighting.

• _____ is crucial to both perception and memory and depends on the inferotemporal cortex

cross-modal matching

• As you walk along, you may also hear birdsong, and you need to match songs with visual input. This process of matching visual and auditory information is called _____

• It likely depends on the cortex of the superior temporal sulcus

long-term memory processes

• As you see more and more birds, you must form memories that you can access later.

• Furthermore, as you see different birds, you must access their names from your memory

• these _____ depend on the entire ventral visual stream as well as the paralimbic cortex of the medial temporal region

Affective Responses; amygdala

characterizes your subjective feelings about a stimulus, is a function of the _____

Spatial Navigation; hippocampus

When you change routes to avoid the snake, you use the _____, which contains cells that code places in space. Together, these cells allow you to navigate in space and to remember where you are

fusiform face area; parahippocampal place area

• _____ is active for faces

  • Lesions to the right temporal lobe have a greater impact on the ability to process faces than do lesions to the left temporal lobe

• _____ is active for scenes

auditory cortex

• speech perception (if relevant)

  • Recognizable voice (match to face)

• cells in the _____ respond to different frequencies and help humans differentiate between three prominent sound types:

  • Speech (can differentiate speech from singing)

  • Language (can recognize someone speaking a diff. language)

  • Music (can differentiate speaking & singing, music & noise)

posterior pyriform cortex

• _____ is contained within the temporal lobe

• connects with the entorhinal and perirhinal cortices and the amygdala, connecting olfactory sensations to memory and emotion

Fusiform face area

• aspects of faces, perception of unique identity

  • Sex/Gender, Ethnicity/Ancestry, Age, Species

  • Unknown identity / Known identity

occipital face area

• early perception of facial features

  • It is a face

  • Two eyes, Nose, Lips, Cheeks

  • Freckles, lipstick, facial hair

Anterior temporal Lobe

• personal identity, name, and biographical information

  • Name, recognition, memories, opinions

Inferior Frontal Gyrus

• social cognitive functions, speech (*Broca’s Area)

  • Are they speaking to me? Do I need to respond?

  • What kinds of things do they usually say?

Orbitofrontal Cortex

• decision-making, emotion

  • Make decisions based on the facial expressions of another person

  • Interpreting emotion

Amygdala

• emotion

  • Their emotion

  • Your emotion towards them

Dichotic listening Task

• Assessment of auditory-processing capacity

• two different auditory stimuli simultaneously (usually speech), directed into each of their ears through the use of headphones.

  • Right: two – four – six

  • Left: four – three – one

Visual Object and Space Perception Battery

• A collection of tests that each assess a particular aspect of object or space perception

• making sure only visual/space perception is being assessed

The Rey Complex Figure Test

• Very commonly used to assess perception and visuo-constructional abilities

• Individuals are also tested on recall trials to examine visual memory abilities

• Copy trial

• 3-minute Immediate Recall trial

• 30-minute Delayed Recall trial

Token Test

• The test of choice for language, comprehension

• deficit in language comprehension could result from any lesion in any of the language zones (parietal, frontal, temporal lobes)

occipital lobe

• region on the _____ is the calcarine sulcus

• The primary visual cortex (V1) can be found here, and the calcarine sulcus divides our visual world into halves — the upper and lower half

macula; retina

• is the part of your eye that processes what you see directly in front of you (your central vision).

• part of your _____ which is the light sensitive layers of nerve tissue at the back of the eye that receive images and sends them as electric signals through the optic nerve to the brain

  • backward and upside-down orientation

    • left is on the right, right is on the left

    • top is on the bottom, bottom is on the top

thalamus (LGN); calcarine sulcus

• after being processed in the retina, the visual stimuli are sent to the ______ and then to the visual cortex

• when the stimuli reached the visual cortex, they are organized around the _____

left; macular; peripheral; top

• RULE 1: _____ side of retina, _____ thalamus, _____ visual cortex

• RULE 2: _____ vision, more posterior. _____ vision, more anterior

• RULE 3: _____ of the retina, _____ of the calcarine sulcus

blobs; thick and thin stripes

• when V1 is stained we are able to see structures that appear like “_____”

  • damage to V1 acts & feel as if they’re blind

• when V2 is stained, patterns of _____ emerge

  • one is involved in FORM PERCEPTION

  • another one is involved in COLOUR PERCEPTION

V4

• the major region for colour processing

• the ability to detect and process colour allows us to also detect motion, depth, and position

  • motion: colour may change as objects move

  • depth: shading vs lighter areas

  • position: where is light being reflected

• individuals w/ damage to _____ are only able to see shades of grey & lost the ability to think about colour

V3

form and dynamic form

V5

• motion perception

• individuals damage to _____, if an object is still, it can be perceived, but as soon as it starts moving, it vanishes

Prosopagnosia

• is a neurological disorder characterized by the inability to recognize faces

• “face blindness”

• damage to the fusiform face area, damage to either ventral stream or specific gyrus

visual for action

visual processing required to direct specific movements

action for vision

• when we look at an object, we rarely just stare at it

• we’re often moving our eyes all around it & trying to take in as much visual information as possible

visual recognition

humans possess the ability to not only recognize a specific aspect but also to recognize the bigger picture that it might be a part of

visual space

• visual info. that comes from specific locations in space allows us to direct our movements to objects in those location & assign meaning to those objects

visual attention

helps us filter and process this incoming information and direct us to what is truly important

agnosia

“absence of knowledge”

disconnection; disconnection syndrome

• the cutting of cerebral connections is called _____, and the resulting behavioural effects are called _____

• ex: connecting the 2 halves of the monkey’s brain (corpus callosum and optic chiasm) & removed the amygdala on the left side

association pathways

• are distinguished as either long fiber bundles that connect distant cortical areas or short, subcortical, U-shaped fibers that connect adjacent cortical areas

projection pathways

include ascending fibers from lower brain centers to the cortex, such as projections from the thalamus, and descending fibers from the cortex to the brainstem and spinal cord

commissural pathway

connect the two hemispheres and include principally the corpus callosum and the anterior commissure

primary visual cortex (V1)

• is devoid of interhemispheric connections

• represents the visual world topographically, and there is no need for one half of the representation to be connected to the other

anterior corpus callosum

contains fibers connecting the prefrontal complex

body of the corpus callosum

contain fibers connecting premotor, motor, somatosensory, and posterior parietal cortices, from anterior to posterior

posterior corpus callosum

contains fibers connecting the temporal and visual cortices

anterior commissure

connects amygdala and medial temporal lobe areas

commissurotonomy

• for patients with frequent and violent epileptic seizures, surgically splitting the corpus callosum was the relief aka _____

• This surgery also isolates speech in persons with lateralized speech (i.e., in people whose speech only comes from one hemisphere)

• As a result, the dominant hemisphere (usually the left) is able to speak and process language (read, write), and the non-dominant hemisphere is not

agenesis of the corpus callosum; hypoplasia; hypogenesis; dysgenesis

• is a surprisingly common cerebral malformation in humans in children with developmental disabilities

• _____ underdevelopment/thinness

• _____ partial agenesis

• _____ malformation