CogNeuro Midterm 2

Phonological loop

Stores verbal working memory

Word length effect

Longer words take more time to pronounce, so you can’t hold as many in the phonological loop

Articulatory suppression

Word production, like being told to repeat “the the the the” over and over interferes with working memory rehearsal

Modality

Specific sensory channel through which information is perceived

Visual spacial sketchpad

Visual working memory

Mental rotation

Rotating an object in your mind. The longer an object takes to rotate, the longer it takes to recognize

Episodic buffer

Integrated information from independent sources (phonological loops, visuospatial sketchpad, long term memory)

Central executive

Supervises and coordinates the other systems (attention, splitting attention, switching attention, ignoring)

Preservation

Repeatedly performing the same action or thought even though it is not working because at one time it was successful

Declarative memory

Memory we are aware of

Episodic memory

Personal memory of an event (declarative)

Semantic memory

Knowledge about facts (declarative)

Patient KC

Showed a dissociation between semantic and episodic memory

Implicit/non-declarative memory

Memories we are not explicitly aware of

Procedural memory

Knowledge of how to do things, like driving a car (non-declarative)

Anterograde amnesia

Inability to make new memories following a lesion

Retrograde amnesia

Failure to remember events prior to lesion (Hollywood Amnesia)

Memory systems impaired by amnesia

Episodic memory and sometimes semantic memory

Memory system spared by amnesia

Working memory, non-declarative memory, and semantic memory sometimes

Ribot’s Law

Recent memories are easier to forget than older memories

Medial temporal lobe’s memory structure (hippocampus)

Consolidates memory working memory into long term memory, assists in forming and recalling spacial maps, processes strong emotional memories, and is essential for declarative memory

Long term potentiation

Persistent strengthening of synapse based on recent patterns of activity. “Neurons that fire together wire together”

Cognitive map theory

O’Keefe and Nadel argue that rat hippocampus stores allocentric spacial maps of the environment, meaning it’s independent of the animal’s viewpoint.

Cognitive map theory evidence

Place cells respond maximally when the animal is in a certain location

Place cells

Hippocampal neurons that fire when an animal is in a specific location, and form a cognition map of the environment

Fronto-temporal-parietal circuit

Part of the brain responsible for the phonological loop

Delayed response task- activity of a single neuron

Single cells in PFC are activated when a target appeared. The cell remained active after the target was removed. Activation suggests maintaining memory

Ventrolateral PFC

Short term retention of spatial information (maintenance)

Dorsolateral PFC

Updates new locations (manipulation)

Petride’s theory of Working Memory

Assumed division of PFC into at least two separate processes (maintenance and manipulation)

Self-ordered pointing task

On each trial, choose an object you haven’t chosen before. The position of the objects will change and you’re required to keep track of multiple objects at a time. Damage to Dorsolateral PFC leads to disruption

Action

The outcomes of a number of cognitive processes that translate the goals and intentions of an individual into a motor output

Movement

A physical act that is not necessarily cognitive

1st Level of Action

Vision, somatosensation, motor output

2nd level of action

Object recognition, sensory-motor transformation, motor commands

3rd level of action

Knowledge, object-based actions, stored action schemas

4th (top) level of action

Goals!

Homunculus problem

Explaining voluntary acts without assuming a cognitive process is voluntary

Prefrontal cortex’s role in movement

Higher level planning by evaluating consequences and making motor pattern decisions

Hemiplegia

Paralysis on one side of the body

Contralateral control

Right side of the brain controls left side of the body and vice versa

Direction tuning

The property of a neuron or neural circuit to respond most strongly to stimuli moving or pointing in a specific direction

Population vectors

The sum of the preferred tunings of neurons multiplied by their firing rate

Broadman’s area 6 (premotor cortex)

Involved in selection and maintenance of goals and responses

Damage to premotor cortex (B6)

Does not impair physical movement but actions become inappropriate or disorganized

Broadman’s area 6 (Supplementary motor area)

Deals with well-learned actions

The SAS model (Norman and Shallice 1986)

Some actions are automatic. Some actions require setting up novel actions/cognitive procedures

Automatic actions (SAS model, Norman and Shallice)

It’s like driving a familiar route- requires minimal attention and little prefrontal activation

Novel actions/cognitive procedurals (SAS model, Normal and Shallice 1986)

Like learning to dance- requires full attention and prefrontal cortex

Activation comprehension and imitation

Caused by mirror neurons!

Mirror neurons location

Respond to observed and self initiated actions. Perhaps the basis of learning via imitation and understanding the action of others

Mirror neurons location

VPA (whatever that is)

Mirror neurons location in macaque brains

F5

Basal ganglia function

Imitating and executing internally generated movements and linking one action to the next. Additionally, modifying the activity in the frontal motor structures to influence movement probability

Basal ganglia damage

Leads to hyperkinetic and hypokinetic disorders

Basal Ganglia

CGPSSV (Caudate Nucleus, Globus pallidus, Putamen, Substantia Nigra pars reticulata, subthalamic nucleus, ventral pallidum

Basal Ganglia disorder: Parkinson’s disease

Causes the worsening ability to move

Basal ganglia disorders: Huntington’s disease

Hyperkinetic, excessive, dance-like movement/chorea

Sensation

The effects of a stimulus on the sensory organs

Perception

The organization and interpretation of that sensory energy

Human visual system

Eye, thalamus, V1

Retina

The back part of the eye that has rod and cone cells

Rod cells

Photoreceptors from the fovea, concentrated in the periphery. Only see black and white. Specialized for low light

Cone cells

Photoreceptors specialized for high level of light, specialized for the detection of wavelength. Concentrated in the fovea and reduced in the periphery

Fovea

Small pit in the retina where cone cells are the most concentrated

Retinal ganglion cells

Last layer of cells in the retina, their axons form the optic nerve, they respond to changes in lighting in their receptive fields that have a complex center-surround response pattern

Receptive field

Region in space in which stimuli modulate the firing rate of a neuron compared to its firing base rate

Center surround receptive fields

Retinal ganglion receptive field that enhances the detection of edges and contrast by having a central area with 1 response (e.g., excitation to light) and a surrounding area with the opposite (e.g., inhibition to light)

Optic nerve

The point at which the optic nerve leaves the eye; no photoreceptors are present

Geniculostriate pathway

Visual information pathway from the retina to the primary visual cortex (optic nerve, optic chiasm, optic tract, lateral body, geniculate (thalamus), visual cortex/occipital lobe

Attention

the cognitive process of selectively focusing on and processing specific information while ignoring other stimuli

Inattentional blindness

Failure to notice a change when your attention is directed away from it

Change blindness

Failure to notice change between two alternating scenes connected by blank screen

Dichotic listening

When people with headphones have different messages presented to each ear, they can focus on one and ignore the other

Cocktail party effect

Being able to listen to one voice with many overlapping voices, like in the instance of a cocktail party

Spatially selective attention

We can direct attention to a specific area of space (covert orienting. Overt orienting. Exogenous orienting. Endogenous orienting)

Posner cuing paradigm

Using a cue to direct attention to a certain location

Covert orienting

Moving attention without moving eyes or head

Overt orienting

Moving attention by moving the eyes

Exogenous orienting

Bottom-up cue

Endogenous orienting

Top-down cue

Object based attention

We can attend to one object and ignore another at the same location

Fusiform face area

More active when attending to a face

Parahippocampal place area

More active when attending to the house

Attentional blink

People are “blind” to a second target if it appears within 400 milliseconds after the first and is followed by distractions

Temporal attention

We can direct attention to a specific point in time

Visual search

Task of detecting the presence or absence of a specified target or object in an array of other distracting objects

Simple feature search

Finding a target item in a field of distractors. Pop out effect

Conjunction search

The target has two or more relevant features. Number of distractors matters

The efficiency of visual search

Quantified as the average increase in reaction time for each item (the larger the slope (more ms/item) the less efficient the search

Parallel search

multiple stimuli are processed at the same time (attention not required)

Serial search

Only one stimulus is attended at a time (attention required)

Guided search

Attention can be restricted to a subset based on basic features

Feature integration theory

When perceiving a stimulus, features are “registered early, automatically, and in parallel, while objects are identified separately” and at a larger stage of processing

Feature integration stages

1. Mind splits objects into “free-floating,” non-connected features

2. Feature recombination which requires focused attention

What feature integration stage is pre-attentive (without consciousness)

The first integration stage

Illusory conjunctions

When objects are presented briefly, and people aren’t able to focus on them, they re-combine incorrectly

Brain areas involve in attention

Parietal lobe- posterior parietal cortex. Frontal lobe- frontal eye fields

Hemispheric specialization

Right hemisphere sees mostly left visual field but also sees some right. Left hemisphere only sees right visual field