Midterm Study Guide

Define Latent Learning

Learning without receiving rewards or punishments

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• Proponent: Edward Tollman

  • He also discovered cognitive map: mental representation of an area

Explain the Neuron Doctrine

Is a fundamental principle in neuroscience that describes…

1. Nervous system composition: individual, specialized cells called neurons.

2. How neurons communicate: at specialized junctions called synapses rather than in a continuous network (i.e. net theory)”

Who is a proponent of the Neuron Doctrine?

Santiago Ramon y Cajal

What is an action potential?

What is it?

• A neural impulse/brief electrical charge that travels down axon

Function?

• encode information and trigger the release of neurotransmitters to send messages throughout brain and body

How it works?

• When a sufficient electrical signal is received → action potential is triggered → neurotransmitters released at the synapse → messages sent throughout body

What is a neurotransmitter?

a chemical messenger that transmits signals between neurons, essentially allowing nerve cells to communicate with each other by carrying "messages" across the tiny gap between them, known as the synapse

Differentiate action potential and neurotransmitters 

An action potential is an electrical signal that travels along the axon of a neuron that triggers the release of neurotransmitters at the synapse.

The neurotransmitters are the chemical signals that cross the gap to the next neuron;

• essentially, the action potential generates the signal within the neuron, while the neurotransmitter is what carries the signal/message across the synapse to the next neuron.

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An action potential is the rapid electrical signal within a neuron

• occurs in the axon

• Is a "wave" of electrical activity that triggers release of neurotransmitter

A neurotransmitter is the chemical messenger

• Is what’s released from the axon (terminal) after action potential

• Carries the message

• Crosses the synapse → bind to receptors of another neuron → connection allows for communication between two 

Define feature detectors

• Nerve cells that respond to specific features of a stimulus

  • (i.e. shape, angle, or movement)

    • Location:

      • visual cortex of brain

feature detectors proponent

David Hubel and Thorsten Wiesel

What is sensory code, and what are its two types

Sensory code is how neurons represent stimuli

• Two types:

  1. Specificity coding

  2. Population coding

Specificity Coding

An individual specialized neuron fires to represent stimuli or various concepts

Population coding

A large ensemble of neurons fire to represent stimuli or various concepts

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A population of neurons required

Differentiate specificity and population coding 

specificity coding focuses on individual neuron activity, while population coding relies on the collective activity of many neurons to represent information. 

Example:

• Specificity coding:

  If a single "grandmother cell" in the brain only fires when you see your grandmother, that would represent specificity coding. 

• Population coding:

  If a group of neurons in the visual cortex collectively encode the features of a face (like eye shape, nose shape, mouth position), with no single neuron solely representing the entire face, that would be an example of population coding. 

Explain localization of function 

"Localization of function" refers to the concept that specific areas of the brain are dedicated to performing particular functions

• different parts of the brain control different behaviors and cognition

Is memory localized?

No

• Jean Pierre Flourens

  • Lesioned specific brain regions, discovered memory was not affected by which area was destroyed

Who are proponents of localization?

John Hughlings Jackson

• suggested that each muscle in the body was controlled by a specific region of the brain

Marc Dax​/Paul Broca

• Discovered damage in specific area of left hemisphere in patients with “expressive aphasia”

• “broca’s area”

Carl Wernicke

• Discovered a separate brain region in the left hemisphere associated with “receptive aphasia​”, also known as language reception (cannot decode language)

• “Wernicke’s Area”

Wilder Penfield

• Pioneer of brain mapping

What is a lesion in the brain?

Destroyed brain or glial matter

• May be incidental by surgery or from stroke, tumor, epilepsy, blunt trauma, etc.

• May be intentional (brain ablation) to determine function of brain of nonhuman animal

What is double dissociation?

Patients with a specific lesion are compared with…

1. Control group

2. Patients with lesions in brain area A

3. Patients with lesions in brain area B

Purpose: To identify specialized functions by comparing two patients.

Explain the significance of double dissociation

a double dissociation provides stronger evidence that the impact on cognitive function(s) due to lesions are independent of each other.

Define distributed representation 

A stimulus activates multiple areas of the brain to fully comprehend all aspects of a presenting stimulus.

• mnemonic: Information is distributed across the brain.

Sensation

the activation of sensory organs and nervous system once they receive stimulus information from the environment

• activation of sensory organs by stimuli​

Perception

The conscious process of interpreting, organizing, and analyzing sensory information

• enables us to recognize meaningful objects and events

Differentiate sensation and perception 

Sensation is the physical process of detecting and receiving sensory information

Perception is the conscious interpretation of that stimulus.

What factors make pattern recognition more difficult (?)

1. Inverse projection

2. image clutter

What is the inverse projection problem and how does it make pattern recognition more difficult

• The idea that a single image on the retina could be caused by various different stimuli​.

  • The problem is we could very well perceive what we’re seeing as WRONG

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    • EX: different objects at varying distances can cast the same retinal image, making it impossible to definitively know the true object without additional information or context clues. Is this person REALLY holding a tiny Eiffel Tower in her hand?

What is the image clutter problem, and how does it make pattern recognition more difficult

When many overlapping objects are scattered throughout a scene​ at once, object recognition becomes difficult— we cannot make sense of what we’re seeing

Bottom-up processing

More “simple” processing in that perception is guided merely by the basic features; refers to interpreting information based solely on the sensory input received, without relying on prior knowledge

• starts with raw data and builds upwards

  • EX:​

Top-down processing

Using existing knowledge and expectations to interpret new sensory information, essentially guiding perception with pre-existing ideas about the world

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More “applied” processing in that perception is guided by assumptions, experience, and expectations​

• starts with known info and applies to basic perceptions​

Differentiate bottom-up and top-down processing 

Bottom-up processing involves building perceptions based solely on incoming sensory information, without relying on prior knowledge

Top-down processing involves using existing knowledge and expectations to interpret sensory information, essentially "filling in the gaps" based on what you already know

• In simpler terms, bottom-up processing starts with the details and works towards a whole picture, whereas top-down processing starts with a general idea and uses it to interpret details. 

Define perceptual set 

a sub-category of top-down processing

a mental predisposition to perceive one thing and not another

• ex: Whichever image, left or right, you're exposed to first influences your perception of the middle image-- in a sense, its like you’re priming the person to perceive a specific image.​

  

Define closure 

a psychological principle where the mind perceives incomplete shapes or patterns as whole objects. This concept illustrates how our brain fills in gaps in visual information to create a complete picture, demonstrating the tendency to see things as unified and complete rather than fragmented.

This image suggests the presence of a white triangle, even though there isn’t one, due to how the objects in the image are arranged, which strongly suggests there should be one there

Explain Bayesian Inference (prior probability and likelihood) 

Bayesian inference: the use of mathematical probabilities to describe the process of perceptual inference​

• Prior: initial belief about the chances of an outcome​

• Likelihood: the extent to which the available evidence is consistent with an outcome​

Define Plasticity 

the brain's ability to adapt (or change) in response to experiences, learning, damage, or environmental stimuli.

• Allows the brain to form new neural connections, strengthen existing connections, weaken or prune unnecessary connections, recover from brain injuries, learn new skills, and recognize new types of stimuli

  • most apparent in children​

Define the Stroop task

naming colors takes longer when the word and the color it’s printed in are incongruent​

• Conflicting messages make responding quickly harder

• Emotional Stroop task: naming the color of words that provoke strong emotions takes longer​

  • Attentional bias: some people pay particular attention to certain kinds of stimuli ​

Why do people have difficulty with the Stroop task

it creates a conflict between the automatic process of reading words and the intentional process of identifying colors, meaning that when presented with a word written in a different color, the brain is naturally inclined to read the word rather than state the color, leading to interference and slower response times when the color and word don't match; essentially, the brain is trying to perform two competing tasks at once. 

Define change blindness

Failing to detect a change in a scene or object

Define inattentional blindness 

when attending to certain things, we often completely miss things we aren’t attending to​

Explain the binding problem of attention 

we analyze features of stimuli separately, but we perceive them holistically​

Explain the isolated features/combined feature effect 

visual search tasks (finding a target in a visual display with many distracters) are easier when the target stimulus differs from all the background stimuli on a single feature as opposed to when multiple features must be processed​

Explain the feature present/feature absent effect 

people can locate a feature that is present quicker than an absent feature​

Recall

a measure of memory in which the person must retrieve information learned earlier without help, as on a fill-in-the-blank test.

Recognition

a measure of memory in which the person identifies (or recognizes) items previously learned with help, as on a multiple-choice test.

Differentiate recall and recognition 

recall is actively remembering details, while recognition is passively identifying something familiar

• Recognition is the ability to recognize something you have seen before, while recall is the ability to remember something without being prompted. Recognition takes less cognitive effort.

What is the 3-stage modal model?

1. Sensory memory

2. Short-term (or working) memory

3. Long-term memory

Sensory memory

The immediate, very brief and accurate, recording of sensory information in memory.

• 1 second

• Two types: Echoic and Ionic

Short-term (working) memory

activated memory that holds 4-7 units of info briefly, such as digits of a phone number while calling, before the information is stored or forgotten.

• 30 seconds

Long-term memory

the relatively permanent and limitless storehouse of the memory system; Includes knowledge, skills, and experiences.

• Enduring (meaning it has the potential to last a lifetime)

Differentiate…

• sensory memory

• short-term/working memory

• long-term memory

• Sensory memory is the brief initial perception of sensory information, lasting only fractions of a second

• Short-term memory holds information for a few seconds to minutes

• Long-term memory stores information for extended periods, potentially a lifetime, with a much larger capacity than the other two

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Sensory memory is the first stage where information enters the brain, then moves to short-term memory if attention is paid, and finally may be transferred to long-term memory for permanent storage. 

Implicit (procedural) memory

Retention of learned skills or classically conditioned associations

• Unconscious

Explicit (declarative) memory

Recollection of facts, events, or concepts that one can “declare”

• Conscious

  • Two Types:

    1. Semantic​

    2. Episodic

Differentiate Explicit (declarative) vs Implicit (procedural) memory

Explicit (declarative) memory refers to consciously recalling facts and events,

while implicit (procedural) memory involves the unconscious knowledge of how to perform a skill, without actively thinking about it

a) Episodic memory

Part of explicit (conscious) memory systems

• Recollection of personally experienced events.

  • Remembering specific timeframes of events in our life​

  • Events of our life we can play out like an episode; we can take ourselves back to that time and place as if we’re there

b) Semantic memory

2/2 explicit (conscious) memory systems

• Recollection of facts and general knowledge.

  • things u learn in school (dates, names, etc)

Differentiate episodic and semantic memory 

Episodic memory refers to the recollection of personal experiences and specific life events, including details like when and where they occurred, while semantic memory stores general knowledge and facts about the world, devoid of personal context or specific timeframes; essentially, episodic memory is "remembering" a specific event, while semantic memory is "knowing" a fact

Proactive interference

Older info disrupts the retrieval of newly learned info​

• (Pro → new)

Retroactive interference

Newly learned info disrupts retrieval of old info

• (Retro → old)

Differentiate proactive and retroactive interference 

"old" information interferes with "new" in proactive interference, and "new" information interferes with "old" in retroactive interference

How many units of information did Miller suggest we can store in working memory?

4-7 units

Explain apparent motion 

a visual illusion in which two stimuli separated in time and location are perceived as a single stimulus moving between the two locations due to persistence of vision​

Differentiate the components of working memory: Phonological loop and Visuospatial sketchpad

• The phonological loop is working memory for sounds

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• The visuospatial sketchpad is the working memory for visual stimuli and for the physical layout of objects in an environment​

Define object permanence 

objects continue to exist even when not sensed​

• infants lack this

Explain the serial position effect (primacy and recency) 

(recency effect) our tendency to recall items last in a list best

• Related to short-term memory

(primacy effect) our tendency to recall items first in a list best

• Related to long-term memory

Retrograde amnesia

an inability to retrieve information from one's past.

Anterograde amnesia

an inability to form new memories.

Define priming 

the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response.

• preparing us to respond a certain way

Define the Propaganda Effect

statements that have been heard before are more likely to be assumed as true​

Define Mere Exposure Effect 

the phenomenon that repeated exposure to novel stimuli increases liking of them.

Explain what was learned from studying Henry Molaison

Hippocampi removed → can’t form long-term explicit (declarative) memories​, can still form long-term implicit (procedural) memories​

• cannot create new memories, but can remember older memories

• trapped in the present

Explain what was learned from studying Clive Wearing 

Hippocampi damage due to a virus​→ anterograde and retrograde amnesia for episodic memories​