Biological Psychology Midterm 2

memory

the ability to store and retrieve information; the specific information stored in the brain

explicit memory

the conscious, intentional recall of facts and personal experiences

episodic memory

memories of events/ happenings of life/ in the past, helps you make decisions about the future

semantic memory

knowing facts (ex: the 3rd president)

implicit memory

unconscious, long-term memory that influences your behavior without conscious effort (ex: you are better at skiing the 2nd time you do it)

procedural learning

the process of acquiring skills and habits through practice, which eventually allows them to be performed automatically without conscious though

is there only one type of memory system? 

no, there is sensory memory, working memory, and short and long term memory 

long term memory

“archive” of information about past events and knowledge learned, works closely with working memory. storage stretches from a few months ago to as far back as one can remember. more recent memories are more detailed. different storage mechanisms, not perfect like a photograph

short term memory

temporary storage system for a small amount of information that is actively being used, typically lasting for about 15-30 seconds 

sensory memory

the brief retention of sensory information from the 5 sense, holding it for a fraction of a second to a few seconds before it is either processed or forgotten

working memory

the cognitive system that allows you to temporarily hold and manipulate information for immediate tasks 

role of the hippocampus in memory

responsible for one’s ability to encode new long-term memories

what did HM have surgery on/for

on his hippocampus and other parts of the medial temporal lobe for severe epilepsy

what were the effects of HM’s surgery

unable to form new explicit long term memories, has normal STM, working memory, has excellent recall for his youth. deficit: information transfer from STM to LTM

retrograde amnesia

loss of memories formed before a trauma such as accident or surgery, can form new memories

anterograde amnesia

inability to form new memories after onset of a disorder, but can remember memories from before the onset

several kinds of learning and memory 

• HM practice mirror drawing skills. he improved motor skills but did not remember doing the tasks

• amnesic patients can learn to

 read mirror-reversed text. they do not remember practicing and the problem is not verbal

declarative memory

facts and information, past information (things you know that you can tell others), HM was unable to form new ones

non-declarative (procedural) memory

improved performance, not conscious recollection of how you learned (things you know that you can show by doing), HM was capable of forming this one

cortex role in memory

stores memories once they are formed (retrograde amnesia typically occurs due to damage to cerebral cortex)

skill learning 

learning to perform a task requiring motor coordination

priming (repetition priming)

exposure to a stimulus facilitates subsequent responses to the same or similar stimulus

associative learning

the association of two stimuli or of a stimulus and a response

types of declarative memory

episodic and semantic

types of non declarative memory

skill learning, priming, conditioning

three stages to create and store memories

encoding, consolidation, and retrieval

encoding

sensory information is passed into short-term memory

consolidation

short-term memory transferred to long-term storage

retrieval

stored information is used

where does permanent storage (consolidation) occur

typically in the regions where it was first processed

retrieval from LTM

retrieving information can strengthen memory trace and can also alter memory trace

evolutionary theory

the gradual change of a species

Darwin’s observations

reproduction will increase a population rapidly unless factors limit it; individuals of a species are not identical; some variation is inherited; not all offspring survive to reproduce

adaptations

the ones that increase the likelihood of having offspring will eventually predominate the population; most important organizing principle in the life sciences

modern evolutionary theory

natural selection + genetics + molecular biology

convergent evolution

results in similar solutions in different species (ex: body form of tunas and dolphins)

homology

similarity based on common ancestry, as with forelimbs

brain size related to intelligence

there is no correlation. brain size and body size usually correlates. humans, dolphins, and crows kind of diverge from this. difference in brain size and structure are evident in species that adopted novel food—seeking behaviors 

brain structures

animals who depend on hearing, vision, or memory for their food develop larger related brain structures. 

vertebrate nervous systems share basic features

develop from a hollow dorsal neural tube, bilateral symmetry, segmentation, hierarchical control, separate peripheral and central systems, localization of function

brain size and primates

in proportion to overall brain size: the medulla becomes smaller, the cerebellum retains its relative size, and the cortex becomes larger

sensory receptor cells

detect a stimulus

receptor cells

within the organ; convert the stimulus into an electrical signal. they detect energy in the form of light, sound, chemicals, and pressure

how does the brain differentiate senses

all sensory information is converted into action potentials, different sensory information via dedicated neural pathways. sensory information separated in distinct brain regions in cerebral cortex

sensory transduction

conversion of energy from a stimulus into a neural signal, occurs in sensory receptors

receptor potentials

local changes in membrane potential

stimulus intensity conveyed by a single neuron

via frequency of its action potentials

stimulus intensity conveyed by multiple neurons

via recruitment of more neurons

somatosensory system

detects touch and pain

how is intensity encoded in sensory systems

stronger the system → faster neuron firing and sometimes more neurons respond to the same stimulus

topographic organization

stimulus location mapped onto sensory receptors, everything is contralateral

six aspects of sensory processing

coding, adaptation, suppression, pathways, receptive fields, attention 

coding

patterns of action potentials that reflect stimulus properties. sensory systems code for biologically relevant stimuli, or features. some somatosensory neurons detect limb position. some visual neurons detect the orientation of objects. (direction, color → encoded in different areas of brain, different neurons)

adaptation

progressive loss of response to a maintained stimulus (when something is constant, realize it’s not going away, adapt firing rate of neurons)

suppression

adaptation, accessory structures can suppress a constant stimulus (trying to pay attention to one thing, ignoring everything else that is going on around)

top-down processing

higher brain centers suppress some sensory inputs and amplify others

pathways

sensory pathways relay sensory information for further processing

thalamus

relays most sensory pathways

where do most sensory pathways terminate

in the cerebral cortex (everything converges to the same place, but is kept neat)

receptive field

sensory space to which a neuron responds. what excites or inhibits the neuron. they differ in size, shape, and response to types of stimulation. 

attention

process by which we select or focus on specific stimuli for enhanced processing and analysis. two brain regions are important in attention; they are activated when we are experiencing a stimulus: posterior parietal lobe, cingulate cortex (don’t just see things, pay attention to them. just because you see it doesn’t mean you take it in)

primary sensory cortex

first sensory cortical area

primary somatosensory cortex (S1)

receives contralateral touch information

secondary sensory cortex

receives input from primary sensory cortex, expands complexity

secondary somatosensory cortex (S2)

attention, memory, input from both sides of the body

polymodal cells

allow for intersensory interactions. sensory systems influence each other. association areas in the brain show a mixture of inputs from different senses

synesthesia

a stimulus in one modality creates a sensation in another. a person may perceive colors when looking at letters, or taste when hearing a tone. if they were to look at an image with black 5s and 2s and then an image where the numbers are different colors, it would take them the same amount of time to recognize the distinct numbers 

somatosensory perception

information about touch, pain, and temperature are transmitted from sensory receptors to the spinal cord. the spinal cord sends these signals to area in the brainstem (near the medulla). generally, signals are kept separate. but, your brain has a system for relieving itch 

dorsal column system

delivers touch information to the brain. dorsal column of the spinal cord → dorsal column nuclei in the medulla → thalamus → S1

pain

an unpleasant experience associated with tissue damage, it allows us withdraw from pain causing stimulus, recuperate, signal others

congenital insensitivity to pain

inherited syndrome, very dangerous

Mcgill Pain Questionnaire

• sensory discriminative quality: throbbing, gnawing, shooting

• motivational affective (emotional) quality: tiring, sickening, fearful

• cognitive evaluative quality: no pain, mild, excruciating 

anterolateral (spinothalamic) system

transmits the sensations of pain and temperature, free nerve endings synapse on spinal neurons in the dorsal horn, pain information crosses the midline in the spinal cord, before ascending to the thalamus

sound

vibration of air

amplitude

intensity, height of wave, perceived as loudness, decibels (dB)

frequency

cycles/sounds of vibration, perceived as pitch, hertz (hZ)

how do we hear pressure waves

sound from the air enters the ear, vibrates in the eardrum, and is converted into neural signals

route of auditory cortex

external ear → ossicles → cochlea → vestulocochlear nerve

route of auditory cortex

1. sound waves travel through the ear canal to your eardrum and cause it to vibrate

2. vibrations travel from your eardrum to your ossicles (tiny bones in your middle ear)

3. ossicles send the vibrations to your cochlea, which Is lined with hair cells

4. tiny hair cells vibrate and send messages to your auditory nerve

5. your brain receives this information and translates it into sound

• your ear lets you receive vibrations

• your brain lets you perceive sound

tuning curves

graphs of individual auditory nerve fiber responses- show a cell’s response to various frequencies. most within the range of human voice

primary auditory cortex (A1)

located on the superior temporal lobes. processes auditory information

dorsal steam

parietal lobe, further processing of spatial location (where is the sound coming from)

ventral steam 

temporal lobe, analyzes components of sound (what is the sound)

where is Heschl’s gyrus larger

in musicians

amusia

inability to discern tunes. problem recognizing pitch, not rhythms. it is painful to hear music

wavelength

distance between two adjacent crests of vibratory activity. different wavelength perceived as different colors. 

amplitude regarding vision

brightness

two types of photoreceptors

rods and cones

rods

sensitive to low light (night vision), located in peripheral regions of the retina

cones

sensitive to differences in wavelength (color), found in fovea

ganglion cells

axons form optic nerve that goes out to the CNS

fovea

high concentration of cones, high acuity

visual acuity

sharpness of vision; falls off towards to periphery of the visual field 

lateral inhibition

a process where interconnected neurons inhibit their neighbors and produce contrast. important for detecting edges 

vision is contralaterally processed

left visual field → right hemisphere

right visual field → left hemisphere

retinotopic maps

topographic maps of the visual field. in visual cortex most of these maps represent fovea. exist through the thalamus, occipital, temporal, parietal, and frontal cortex

V1 as a warehouse

• V1 detects a line

• have a higher up area that responds to shapes

• have a higher up area that recognizes an object to be a keyboard

• have a higher up area to recognize the object to be an old computer 

V1 (primary visual cortex)

visual warehouse, receives and organizes all input, necessary for conscious perception. has separate representations for location in the visual field, ocular dominance, orientation, and color

blindsight

if you do not have V1. they can see things, but don’t consciously know they can see them