Cognitive Neuroscience Quiz 3

Sensory Memory

milliseconds to seconds

Iconic Memory

seeing an image for a period of time even after it disappears

Echoic Memory

hearing an audio bite for a period of time even after it stops playing

Short-Term Memory

seconds to minutes

Long-Term Memory

days or years

Declarative Memory

explicit memory

Nondeclarative Memory

implicit memory

Procedural Memory

motor and cognitive skills

Perceptual Representation System

perceptual priming

Classical Conditioning

conditioned responses between two stimuli

Nonassociative Learning

habituation sensitization

Episodic Memory

events

specific personal experiences from a particular time and place

Semantic Memory

facts

world, object, and language knowledge

conceptual priming

Global Amnesia

profound forgetfulness
regardless of modality and presentation of information

Amnesic Syndrome

impaired declarative but spared nondeclarative

Anterograde Amnesia

inability to form new memories

Retrograde Amesia

inability to recollect old memories

Patient HM

• severe epilepsy

• surgery to remove both temporal lobes

• anterograde amnesia (no new memories)

• procedural memory still intact

• IQ better and fewer seizures

Animal Model of Amnesia

tested effect of lesions on the hippocampus on learning and memory in monkeys

hippocampal lesions cause

Delay-Dependent Effect

refers to how the passage of time—whether a short working memory interval (seconds) or a longer episodic retention delay (minutes to days)—systematically alters neural processing, memory accessibility, or value discounting

Patient RB

• suffered an ischemic episode (stroke) during surgery leading to severe, enduring anterograde amnesia with minimal retrograde memory loss

• postmortem examination revealed a circumscribed bilateral lesion restricted exclusively to the CA1 field of the hippocampus

Trisynaptic Pathway of Hippocampus

Perforant Path → Mossy Fiber → Schaffer Collisions → Subiculum

Perforant Path

Entorhinal Cortex to Dentate Gyrus

information enters hippocampus

Mossy Fiber

Dentate Gyrus to CA3

neurons in DG important for pattern separation

Schaffer Collisions

CA3 to CA1

neurons in CA3 important for pattern completion and associative memory

high concentration of NMDA receptors sits

Subiculum

primary output region that routes information back to the cortex

Place Cells in MTL (medial temporal lobe)

hippocampal neurons that consistently spike in specific locations within the environment (spatial specificity)

Cognitive Map

the mental representation of a set of relationships

Mechanisms of Memory

Encoding, Consolidation, Retrieval, and Reconsolidation

Encoding

transforms sensory stimuli into a transient neural representation

depends heavily on attention, depth of processing, and the selective filtering of sensory input

Cellular/Synaptic Consolidation

occurs over hours via local protein synthesis and synaptic modifications

Systems Consolidation

occurs over weeks to years through the gradual transfer and reorganization of memory traces from the hippocampus to the neocortex

Retrieval

uses controlled search and cue-driven mechanisms to reactivate stored neural traces back into working memory

Long Term Potentiation

a persistent, activity-dependent strengthening of synapses that increases signal transmission between neurons

• the more often neurons in a pathway fire together, the stronger they become as a system

receptor neurons generate more reception sites to better enhance communication

Hippocampus and Memory Formation

forms new declarative memories

information is initially processed in the cerebral cortex and funneled in through the entorhinal cortex

links sights, sounds, and emotions into a single cohesive episodic memory

Pattern Completion

the brain's ability to fill in the missing pieces of an experience from a partial, degraded, or ambiguous cue

Mnemonic Description Tasks

participants are shown “lure” items during memory tests

if a participant mistakes a new, similar item for an old one, it is often a behavioral sign that the brain filled in the gaps based on the old memory

Neuroimaging and Eye Tracking

when people see a partial cue, their eyes and brain-activation patterns mimic what happened when they first learned the full event

Pattern Separation

the process of turning similar inputs into distinct, non-overlapping memory traces so they do not get mixed up

Cortical Reinstatement

the neocortex reactivates the original sensory, emotional, and conceptual details of the event

Reinstatement Hypothesis

remembering a past event requires the brain to re-activate the specific patterns of neural activity that were originally present when the event was first experienced and encoded

Multi-Voxel Pattern Classification

neuroimaging technique that uses machine learning classifiers to decode distributed patterns of brain activity across multiple voxels rather than looking at single-voxel or regional averages

Voxel

a small, three-dimensional cube or volume element of brain tissue used to map and measure brain activity or structure in neuroimaging

Multi-Dimensional Space

the activation values of N voxels in a brain region as coordinates in an N-dimensional space

Information Sensitivity

detects fine-grained neural population codes and distributed representations that show no differences in overall mean activation

Support Vector Machines

a hyper-plane or kernel function to separate data points belonging to different experimental conditions

Representational Similarity Analysis

compares second-order patterns or representational dissimilarity matrices across stimuli, subjects, or computational models

Searchlight Mapping

iteratively tests local multi-voxel information patterns across every small region of the whole brain

Feature Selection & Preparation

choose a region of interest (ROI) or run a whole-brain searchlight, often avoiding heavy spatial smoothing to preserve fine-grained patterns

Classifier Training

feed multi-voxel activation vectors paired with experimental labels into a machine learning model

Cross-Validation

test the model on independent data folds to evaluate generalization performance without overfitting

Visual Object Decoding

distinguishing categories like faces, houses, tools, or scenes in visual and temporal cortices

Memory & Cognition

tracking memory reinstatement, personal autobiographical memories, or task-state representations

Informational Connectivity

measuring how distributed information patterns co-fluctuate across different brain regions over time

William James (1890)

founder of attention theory in psychology

“the taking possession by the mind, in clear and vivid form”

Eye Movements - Overt Attention

most direct way to shift attention

poor resolution in periphery, foveal gaze retains most attention

Attention LImitations

energy metabolism in the brain can only support `0.1 spikes per second per neuron on average

can only perform on action at a time

Downstream Processing

ignore irrelevant neuronal signals

boost reliability of relevant neuronal signals

Attention Cost

Focusing on one area/object of attention can cause you to lose data/no consolidate other pieces of information

Spatial Cueing

using arrows to covertly indicate spatial location of soon-to-appear items

Preattentive Visual Search

parallel

processing of each item occurs at the same time and directs attention accordingly

Attentive Visual Search

serial

processing occurs sequentially (one at a time) and attention is directed after target is processed

Conjunction Search

target object features are similar to distractor features

Pop-Out Search

target object is distinctly different from distractor items

Triesman’s Feature Integration Theory

2 Stages of Processing:

• Preattentive Stage

• Focused Attention Stage

Preattentive Stage

the featural “primitives” in a visual scene are all extracted in parallel across the whole

Focused Attention Stage

attention is directed to a location

the primitives there are combined to form a whole

Visual Neglect

following lesions to right parietal lobe, patients may neglect left visual field

Optic Ataxia

inability to move the hand to an object by using vision

Ocular Apraxia

inability to voluntarily control the gaze

Simultanagnosia

inability to recognize more than one object shown at the same time

Balint’s Syndrome

a rare neurological disorder caused by damage to the posterior parietal and occipital lobes of the brain

Bottom-Up Attention Division

feature division

“reflexive” or automatic

exogenous - a conspicuous aspect that draws attention to target

fast

Top-Down Attention Division

goal or experience driven

voluntary

endogenous

slow

Goldberg and Wurtz, 1979: Parietal Neglect

showed correlation between spatial attention and neural activity

Posterior Parietal Cortex

right hemisphere neglect or damage can damage attention system damage on both sides

Important Context for Episodic Memory

sequence in which events occurred

the context in which events took place

Depolarization

neuron inside is less negative because sodium ions enter to trigger an action potential

Hyperpolarization

neuron inside is more negative because potassium ions leave the cell after an action potential occurs

Phase-Amplitude Coupling (PAC)

cross-frequency coupling where the phase of a slow brain oscillation modulates the amplitude (power) of a faster brain oscillation

Place Cells in LTM (long term memory)

hippocampal neurons that record sequential order of events and fire sequentially when recalled

Fast-Encoding Hippocampus

high synaptic plasticity

combines multiple sensory details of a new experience onto a mental trace

allows for daily reset

Slow-Encoding Cortex

slow memory trace decay

repeatedly replays daily events to prevent catastrophic interference

Complementary Learning Systems

how the brain balances the need to learn new, specific events quickly without overwriting older, general knowledge

Catastrophic Interference

an artificial neural network’s abrupt loss of previously learned information when it is trained sequentially on new data

Ibotenic Acid

glutamate agonist

excitotoxicity

destroys neurons whose dendrites it comes into contact with

Perirhinal Cortex (PRC)

processes object recognition and memory

participates in both perception and memory

PRC Lesions

animals were selectively impaired on pairs with high feature ambiguity

PRC: Perception

contains mechanisms that aid in mental representation of complex feature connectivity

PRC: Memory

a storage site of complex stimulus representation in short and long-term

Relational Binding

the brain's ability to construct, store, and retrieve flexible associations that link separate items, features, or events into a cohesive memory or experience

Conjuctive Binding

integrates individual features into a single, unified object representation

Eleanor Maguire: Bilateral Hippocampal Damage

patients with damage were able to generate imagined experiences but at a lower experiential level than those of the control patients

Spatial Coherence

a measure of the contiguousness and spatial integrity of an imagined scene

Delayed Non-Match to Sample (DNMS)

a standard behavioral and neuropsychological task used to test recognition memory, working memory, and object discrimination

• participant is shown a sample object

• object is removed for a set interval

• participant is presented with two objects, familiar or novel

• novel choice is rewarded

Ive Brunec and Ida Mommenejad, 2022

the neural bases of the idea that at any moment in time during an event, a participant will be simultaneously representing multiple predictions about what’s to come, one at each of several time horizons and scales

Brunec & Mommenejad: Posterior Hippocampus

activity patterns were found to most closely reflect predictions in short time intervals

Brunec & Mommenejad: Anterior Hippocampus

activity patterns were found to most closely reflect predictions in intermediate-length time intervals

Brunec & Mommenejad: Medial Prefrontal Cortex

activity patterns were found to most closely reflect predictions in long time intervals