Behavioral Neuroscience - Cognitive Functions

Sensory Memory

takes the information provided by the senses and retains it accurately but very briefly. Lasts a few hundred milliseconds to one or two seconds. Part of perception and an important step in storing information into STM

Short Term Memory

temporarily records the succession of events in our lives. Information quickly disappears unless conscious effort is made to retain it. Storage capacity of  about seven items and lasts only a few dozen seconds. Necessary step for retention into LTM. The frontal lobe plays a role in coordination in other parts of the brain for information processing

Long Term Memory

 stores significant events but retains semantic meaning and procedural memory. Unlimited storage and retention period. Can be distorted and is less reliable with age. Across cerebral cortices

Declarative Memory

all the things that we are aware of remembering and can be described in words. AKA Explicit memory.

Non-Declarative Memory

AKA Implicit Memory. Expression through means rather than words.

Semantic Memory

system used to store knowledge of the world. Definition, meanings, traits, norms or customs . Independent of the spatial/temporal context at encoding. Usually spared from amnesia but can be affected by dementia

Episodic Memory

AKA autobiographical memory. Remembers personal experiences. Most affected by amnesia and emotional state.

Procedural Memory

Motor memories. Enables people to acquire motor skills and gradually improve them. Unconscious, composed of automatic sensorimotor behaviors very deeply embedded. Profound amnesia doesn’t affect it, possibility of separate neural pathway.

Priming

behavioral changes that results from recent experiences. Implicit memories made without intention so this is used to uncover them

Conditioning

the association between an action and stimulus. Stimulus does not have to be related to action. Associative learning is evolutionaryily old and can happen without cognitive control

Hippocampus

brain structuve deeply involved in LTM. Temporary transit point for memories from ST to LT storage. High plasticity through strengthening used connections. When axons that make connections to the pyramidal neurons are exposed to high frequency stimulus, the amplitude of the excitatory potential measured increases for a long period

Long term potentiation (LTP)

the underlying molecular changes that are the basis for LT learning

Glutamate

NT released into these synapses. Binds to several different sub

AMPA

receptors on the postsynaptic neuron are paired with sodium ion channels. When glutamate binds to the receptor, sodium ions enter the postsynaptic neuron and causes localized depolarization of dendrites

NMDA

receptors on the postsynaptic neuron are paired with calcium ion channels. Needs LTP activation from AMPA to remove magnesium blocking calcium transport.

Retrograde Amnesia

patients forget events that occurred in their lives before they experienced the trauma. Possible recovery but events closest to trauma are hardest to recover. Episodic memory is most affected compared to semantic memory. Associated with neurodegenerative pathologies (senile dementia, alzheimer’s disease) where progression = memory loss

Anterograde Amnesia

inability to memorize new facts and hence the inability to learn. AKA forgetting as you go. Short term memory and procedural memory are preserved. Often needs acute event.

Phonemes

the basic components of oral language. Elementary units of sound that are combined in various sequences to form morphemes

Morphemes

the smallest sequences of phonemes that can carry a meaning that can be isolated in a sentence in any given language. Not the same as a syllable.

Lexicon

vocabulary of a language that is the set of all words in that language

Syntax

the way that words are used, rules of grammar than enable words to be correctly assembled into sentences

Semantics

the way that complex combinations of sounds or words successfully convey meaning

Babbling

sounds produced in no specific way. Rudimentary syllables that are the initial stepping stones to communciation

Prosody

melody and rhythm specific to the language they head being spoken around them

Broca's Area

left inferior frontal cortex, the first to be associated with a specific function, this one being language

Inferior Frontal Cortex

Wernicke's Area

left posterior temporal lobe, associated with understanding language and producing coherent speech

Left Temporal Lobe

Arcuate Fasciculus

large bundle of axons that connects Broca’s area and Wernicke’s area

Inferior Parietal Lobule

helps the brain classify and label things. Indispensable for language, composed of the angular gyrus and supramarginal gyrus. Connected to both Broca’s and Wernicke’s, serves as an alternative to the arcuate fasciculus. Multimodal and positioned between sensory and somatosensory regions

Denoting

the message received based on what is said, left hemisphere

Connoting

the message received based on how it was said, right hemisphere

Specific Language Impairment (SLI)

involved in producing and identifying basic sounds of language, understanding grammar, and all language disorders unattributed to an intellectual disability, autism, deafness, etc.. Genetics element

FOXP2

gene possibly linked to SLI on chromosome 7 and the protein it encodes. Protein is a transcription factor, binds directly to DNA molecules to regulate expression of other genes

Developmental Dyslexia

affects ability to learn to read, difficulty processing sound structures of language, mapping letters onto said sounds. Different patterns in left hemisphere due to ectopias (clusters of neurons that missed their target location) and microgyria (excessive number of small convolutions), meaning abnormal cell migration may have occurred

Ectopias

(clusters of neurons that missed their target location)

Microgyria

(excessive number of small convolutions)

Broca's Aphasia

Wernicke's Aphasia

Global Aphasia

having both expressive and receptive aphasia. Extensive damage to frontal, temporal, and parietal cortices. Includes Broca’s, Wernicke’s, and suprmarginal gyrus. Poor recovery.

Conduction Aphasia

language comprehension and spontaneous oral expression are normal but difficulty repeating words or phrases. Might be arcuate fasciculus damage

Anomic Aphasia

difficulty finding certain words, use alternatives like “whatsit” or circumlocutions of explaining it instead. Damage to angular gyrus or area above it

Alexia

damage to inferior left occipital and temporal lobes. Cannot read but can write

Agraphia

damage to inferior left occipital and temporal lobes. Cannot write but can reason.

cerebral commissures

connects two cerebral hemispheres

lateralization of function

differentiation of function

aphasia

brain damage producing a deficit in ability to produce or comprehend language (Inferior Left Prefrontal lobe)

apraxia

difficulty performing  movements with either side of the body when asked to do so, but not when performing them spontaneously (leads to speech problems)

Sodium amytal test

A small amount of sodium amytal is injected into one carotid artery; this anesthetizes the ipsilateral hemisphere and allows the abilities of the contralateral hemisphere to be assessed.

Dichotic listening test

A task in which subjects are presented with two messages to two ears over headphones

Cross-Cueing

Represents communication between hemispheres via a non-neural route

Helping hand phenomenon

two hemispheres are presented with different information about the correct choice, are asked to reach out and pick the correct object. Right will pick up left hemisphere’s perception but the left hand will guide the arm to the correct object.

visual completion

simultaneous engagement in completion via chimeric figure test could see the full faces

constituent cognitive processes

underlie complex cognitive functions seem to be lateralized to one or the other hemisphere of the brain

Analytic-Synthetic Theory

suggests that there are two fundamentally different modes of thinking, an analytic mode and a synthetic mode, and that the neural circuitry for each is fundamentally different

Motor Theory

posits that the left hem is specialized for fine motor movement which speech is but one example

Linguistic Theory

is based on the idea that the primary function of the left hemisphere is language