PSY 336 FINAL STUDY GUIDE

Distal Stimulus

the object/event that can actually exist in the world (Ex: the tree or beeping of your phone)

Proximal Stimulus

the physical phenomenon evoked by a distal stimulus that impinges on the specialized cells of the relevant sense.(What activates neurotransmitters, light photons, sound waves, etc. Ex: the reflected light or sound wave. )

Sensation

Direct measure of some aspect of the environment. Allows you to respond to the world. Measures some property of the external world (Physical Stim)

Perception

Something from the world & our brain reacts to it. (Reflex; How your brain interprets the stimulus)

Absolute Threshold

Minimal intensity to detect a stimulus. Defined as the stimulus intensity leading to a 50/50 balance between "yes" & "no" responses.

Resting Potential

Neuron potential when not firing (-70 mV, 70 less than outside)

Eye Anatomy

Know Retina, Lens, Fovea, Optic Nerve, and Visual Pathway

Retina

Holds photoreceptors

Lens

Bends to refract light to retina

Fovea

Lots of cones, high acuity.

Optic Nerve

Blindspot where it goes in.

Visual Pathway

Left hits right retina, crossing over, etc.

Functional Specialization

Areas specialize in what they process. Specific to senses.

Cortical Magnification in V1

More space dedicated to foveal RF. The foveal region of the retina is magnified in the cortex relative to the peripheral regions of the retina.

Perceptual Interpolation

Edges and surfaces assumed to perceive objects as whole.

Border Ownership

Assume the border belongs to only one object in our visual field.

Grandmother Cell

Cell dedicated to grandmother recognition.

Photopigment Bleaching

When a photopigment absorbs a photon, it takes a bit of time before it’s ready to absorb a new one.

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Cell runs out of chemicals to send. Can't send signals, stop seeing color. Stare at bright red light, stare at white screen, green. Causes Afterimage.

Color Constancy

"We take cues from our surroundings to perceive color." Observed light is the product of the SPD (spectral power distribution) of the illumination & reflectance of the object.

Binocular Disparity

Difference in the relative positions of objects in the retinal images of the two eyes.

Oculomotor Cues

Feedback from muscles around and within the eye. Cues from eye movement. Include Accommodation and Convergence.

Accommodation

Relaxing (thinner lens, weaker focus, distant objects) and contracting (thicker lens, stronger focus, closer objects) the ciliary muscles changes the shape of the lens. Relays information for objects within about 2 meters.

Convergence

Eyes turn inward to keep objects in focus.

Deletion and Accretion

Objects are occluded (deleted) or revealed from behind occlusion (accreted). Specific distance where eyes do not cross.

Bimodal Neurons

Respond to TWO modalities (kinds of senses such as visual and tactile).

Motion Aftereffect

Cells get tired, perceive things spinning in one direction as spinning in the opposite.

Broadbent's Filter Theory of Attention

"People do not process unattended stimuli beyond basic physical properties." States that Information is unavailable for later recall.

Cocktail Party Problem

Attend to and understand a single convo in a sea of noise. Other conversations are unattended.

Attention Cueing

Response time faster to the area that attention is allocated to.

Divided Attention

Ability to pay attention to more than one thing at once.

Top-Down vs Bottom-Up Attention

Top-Down Control: Voluntary attention, reflects deliberate conscious goals. “Goal-relevant stimuli.”

Bottom-Up Control: When low-level stimuli “capture” attention independent from the observer’s goals or intentions.

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Top down is effortful conscious focus (trying to take notes at mach 5). Bottom up is whatever grabs your attention against your will (a gunshot). Voluntary vs. Involuntary.

Loudness

Perception of how loud something is, amplitude. Physical pressure of sound.

Ear Anatomy

Know Pinna and Cochlea

Pinna

Weird ear wiggle shape. Useful in perceiving elevation.

Cochlea

In the inner ear. Contains the organ of Corti, produces nerve impulses in response to sound vibrations.

Aphasias

Broca's and Wernicke's

Broca's Aphasia

Frontal lobe damage, impaired production but intact comprehension. (If it’s Broca \[broke-a\], you can’t talk-a)

Wernicke's Aphasia

Near the temporal junction, impaired comprehension but intact production. Can't read either.

Merkel's Disks

Small RF, high tactile acuity. On fingertips, useful for feeling small textures.

Pacinian Corpuscles

Deep pressure and vibration. Large RFs.

Two-Point Threshold

Smallest distance to be able to tell if 2 stimuli can be detected. Sensitive parts have higher acuity.

C-Tactile Mechanoreceptors

The Good Feels transmitters. Free nerve endings present only in hair skin, respond to slow gentle touch

Neuropathic Pain

DMG to peripheral or central nervous system, causes pain in the areas that the nerve is normally linked to. (Arising from damage to the nervous system)

Thermoreceptors

Fire to sudden change in temp, fast

Dorsal Root Ganglion

Sensory info to the dorsal part of the spinal cord. Senses pain, temperature, and touch.

Otolith Organs

The wiggly shit in your ear that helps you understand which way your head is tilted.

Somatosensory Cortex

Processing tactile info, in anterior parietal lobe. Weird naked homunculus dude. Right next to the motor cortex. There's apparently a motor homunculus. RFs correlated to sensitivity of part they're wired to.

Contextual Info (Smell)

Bad at distinguishing smell alone. Context info used to help perceive it.

Adaptation

Reduced sensitivity to odorants which we are continuously exposed to. (Why you don’t smell your perfume after some time)

Cross Adaptation

Adapt to odorants that are similar. Lemon and Lime smells weaken each other.

Olfactory System Path

Doesn't go through thalamus, direct paths to olfactory cortex.

Smell to Hippocampus

Smells super tied to memories. Tied to amygdala too.

Taste Receptor Cell

Transduces taste info.

Primary Taste Cortex (Gustatory Cortex)

Where taste quality (elements of flavor and identification) is processed. Parietal lobe.

Orbitofrontal Cortex

Where we process the reward value of food.

Lateral Inhibition

Excited neurons reduce activity in their neighbors. Increases contrast. Nearby neurons don't send signals. Not just visual.