Perception and Neuropsychology Flashcards

Flashcards covering key vocabulary and concepts related to perception and neuropsychology, including brain structures, visual pathways, disorders, and historical figures.

STEP 1 of sensory information implementation

The process where sensory organs absorb energy.

STEP 2 of sensory information implementation

The process where energy is transduced into a neural signal.

STEP 3 of sensory information implementation

The neural signal is sent throughout the brain where further processing takes place.

Cornea

Transparent outer layer of the eye involved in focusing the image on the retina.

Iris

Muscle that gives eyes their distinctive color.

Pupil

Aperture between the iris muscles allowing more or less light into the eye.

Lens

Allows for accommodation (focusing near and far); cataracts are a clouding of this.

Retina

Contains photoreceptors (rods and cones) that convert electromagnetic energy into a neural signal.

Rods and Cones

Convert electromagnetic energy into a neural signal, performing transduction.

Optic Nerve/Blind Spot

Axons of the ganglion cells; this is the location where the axons of the ganglion cells exit the eye.

Lobes of the brain

4 lobes (frontal, parietal, temporal, occipital).

Subcortex

Eyes, lateral geniculate nucleus (LGN).

Cortex

primary visual cortex (V1); located in the occipital lobe.

Ventral Stream

Involved in pattern visual and is also known as the WHAT pathway.

Dorsal Stream

Involved in spatial vision also known as the WHERE pathway.

Electrophysiology studies

All neurons (cells) fire at a baseline rate; if a cell is interested in something it will either increase or decrease its firing rate relative to baseline.

Rods and Cones response

Changes in illumination.

Retinal Ganglion (RG) Cells response

Spots of light.

LGN cells response

Spots of light.

V1 cells response

Lines of different orientations.

Retinotopic Mapping

Point-to-point mapping of external world onto a brain area.

Center-surround architecture

Enhances Contrast.

Patient DB

Surgical removal of a tumor in the right occipital lobe; left homonymous hemianopia.

Achromatopsia

Absence of colour vision; damage to V4.

Akinetopsia

Absence of motion vision; damage to V5 (MT).

Apperceptive Agnosia

Failure of object recognition due to fundamental failure of visual perception; bilateral damage to V1.

Dorsal Simultagnosia

Failure of object recognition due to a spatial perceptual impairment; bilateral damage to parietal lobes.

Ventral Simultagnosia

Failure of object recognition due to a complex perceptual impairment; ventral stream beyond V4.

Associative Agnosia

Failure of object recognition due to a higher-order complex perceptual impairment.

Bottom-Up Theories

The way the visual system is constructed, starting with analysing low level features (eg, dots, lines) and then building on that until a complex image emerges (eg, face); relies of sensory information.

Top-Down Theories

Hypothesis testing; relies on knowledge and experience.

Retinal Disparity

Two images at different depths will results in different image distances on the retina; brain interprets that difference as depth.

Convergence and Divergence

Objects nearby cause the eyes to converge and objects at a distance causes eyes to diverge; brain interprets those differing signals as depth.

Monocular Cues

Interposition, relative size, linear perspective, height in plane, texture gradient, and light and shadow are all cues to depth perception.

Young-Helmholtz Trichromatic Theory

Postulated the existence of three cones in the retina, each maximally sensitive to a certain colour.

Opponent-Process Theory

Bipolar and RGCs are opponent process cells.

Phrenology

Pseudoscience in which bumps and depressions on the skull were associated the well-developed and under-developed behaviours (Faculties).

Patient Tan

Has a severe language problem and is only able to say "Tan".

Broca's aphasia

Difficulty with language output.

Wernicke's aphasia

Output is normal but comprehension seems impaired.

Current Views of the Brain

The brain is modular; within each sensory module there is further detailed localization of function.

Effects of Damage to the Superior Temporal Gyrus

Auditory region of the brain; deafness, Wernicke's Aphasia, auditory agnosia.

Effects of Damage to the Middle and Inferior Temporal Gyrus

Achromatopsia, akinetopsia, ventral simultagnosia, associative agnosia.

Effects of Damage to the Right Medial Temporal Lobe

Visual memory impaired.

Effects of Damage to the Left Medial Temporal Lobe

Verbal memory is impaired.

Patient H.M.

Retrograde Amnesia and Anterograde Amnesia.

Effects of Damage to the Parietal Lobe

Impairments in integrating sensory information, impairments in the control of movement, impairments in guiding movements to points in space, impairments in abstract concepts, impairments in directing attention, Impairments in Processing Spatial Information.

Effects of Left Parietal Damage

Agraphia, Acalculia, Right/Left Confusion, Dyslexia, Difficulty in Drawing (details).

Effects of Right Parietal Damage

Difficulty in recognizing unfamiliar views of objects, Difficulty in drawing (overall shape), Contralateral Neglect.