Cognitive Psych Exam 1

 

• A rat is placed in a (+)-shaped maze and learns to turn right to find food. Later, the rat is 

placed at the opposite end, and the food cannot be smelled. Which direction does the rat 

turn? Why? 

Rat + maze: The rat turns toward the same spatial location of the food, showing it uses a cognitive map rather than just turning right.

Explain what we can learn about the relationship between the mind and the brain by 

studying the effects of brain disorders. 

Brain disorders: Studying brain disorders shows how specific brain areas support mental functions, revealing links between the mind and brain.

What is Capgras syndrome? What is the neuro-cognitive hypothesis for it we discussed? 

• Capgras syndrome is an extremely rare condition when a patient is able to recognize their loved ones but believes that they are an imposter.  

• A neuro cognitive hypothesis for why this may be would be due to Cognitive and Emotional Appraisal. These things can be affected by a damaged amygdala, prefrontal cortex. 

The glia

1 of 2 cells in the brain !

• it is mainly a support role 

• Guild development of nervous system 

• Repair damage in the nervous system  

• Control nutrient flow to neurons  

• Electrical insulation 

Neurons

1 of 2 cells in the brain!

• basic unit of information processing 

Name and describe the main parts of a neuron. 

• Axons- transmits signals to other neurons 

• Nucleus- sums up signals  

• Dendrites- receives incoming signals  

Action potentials

An action potential is an electrical signal generated when a neuron’s summed inputs exceed a threshold, causing the signal to travel down the axon in an all-or-none manner.

Synapses

A synapse is the small gap between two neurons where communication occurs, separating the presynaptic neuron from the postsynaptic neuron. 

Synaptic transmission

Synaptic transmission is the process by which an action potential causes the release of neurotransmitters into the synaptic gap, which bind to receptors on the postsynaptic neuron and change its membrane potential, potentially triggering a new action potential. 

Hindbrain 

• Top of the spinal cord  

Key life functions 

• Ex. Medulla controls heart rate 

Cerebellum: largest region of brain  

• Movement, balance, also cognition 

Midbrain 

• Relaying auditory information to forebrain  

• Coordinating precise eye movement  

• Source of may neurotransmitter 

Forebrain  

• Surrounds the midbrain and most of the hindbrain 

• Cerebral cortex 

Cortex (cerebral cortex)

The cortex (cerebral cortex) is the outer, folded layer of gray matter in the brain, responsible for high-level functions like thought, language, and voluntary movement. 

The 4 lobes of Cerebral Cortex

• Occipital-visual processing

• Frontal- planning, behavior, voluntary movement, speech

• Parietal- sensory input, touch, spatial awareness

• temporal- auditory processing, memory, language comprehension

Subcortex

subcortex refers to the diverse structures located beneath this outer layer, such as the basal ganglia, thalamus, and hippocampus, which manage essential functions like emotions, memory, and motor control. 

Grey matter

mostly neuronal cell bodies 

White matter

myelinated axons 

Explain the role that the corpus callosum plays in the brain,

• The major commissure (tract of white matter) connecting the brains hemispheres 

• Severed corpus callosum  

A last resort treatment for severe epilepsy 

Severely limits communication between the hemisphere

Lateralization

The brain is divided into roughly symmetrical left and right hemispheres. 

Localization of function

insights from patient studies (Phineas Gage and studying the prefrontal cortex)

Computerized Topography (CT) Scans

a bunch of x rays that show the structure of the brain  

Magnetic Resonance Imaging (MRI)

Detailed photos of the brain to search for abnormalities/injuries. 

Positron Emission Tomography (PET)

used to study the brains neurochemistry and metabolism

Electroencephalography (EEG)

• used to measure the timing of brain activity  

FMRI

looks at the brains activity after various tasks  

ERG

used to see the brains responses to specific events  

Primary Motor Cortex

• What it does: Controls voluntary muscle movements

• Where it is: Frontal lobe, just in front of the central sulcus

• Organization:

  • Body mapped as a motor homunculus

  • Precise body parts (hands, face, lips) = larger area

  • Contralateral control: left side of brain → right side of body, right side → left side

Primary Somatosensory Cortex

• What it does: Processes touch, pressure, temperature, and pain sensations from the body

• Where it is: Parietal lobe, just behind the central sulcus

• Organization:

  • Body mapped as a sensory homunculus

  • Sensitive body parts (fingers, lips) = larger area

  • Contralateral control: left side of brain → right side of body, right side → left side

Explain why they are called “projection areas.” 

They are called projection areas because they are regions of the cortex where information is projected either from the body to the cortex (sensory) or from the cortex to the body (motor). 

Motor Areas (primary motor cortex)

moter= move

Control voluntary movements of the body.

sensory areas (primary sensory cortex)

sensory=sense

Process touch, pressure, pain, and temperature from the body.

From the eyes to within the brain, describe the parts of the visual processing pathway. 

Visual information travels from the retina through the optic nerve to the lateral geniculate nucleus of the thalamus, then to the primary visual cortex in the occipital lobe, and is further processed along ventral “what” and dorsal “where” pathways. 

Rods  

• Sensitive to dim light (i.e. low levels of light) 

• Lower acuity 

• Color blind 

• None in the fovea 

Cones 

• Cannot function in dim light 

• Higher acuity  

• Color-sensitive  

• Mostly in or near the fovea; none in the periphery 

What is the fovea?

• Fovea- The fovea is a small region at the center of the retina responsible for sharp, detailed, color vision. 

• Photoreceptors at the fovea: 

• Cones only 

• No rods 

Blind spot 

• The blind spot is the area of the retina where the optic nerve exits the eye, so no visual information can be detected there. 

• Photoreceptors at the blind spot: 

• None 

• No rods and no cones 

Explain how lateral inhibition promotes edge perception. 

Lateral inhibition enhances edge perception by increasing contrast at boundaries, as strongly activated neurons inhibit neighboring neurons more than weakly activated ones, exaggerating differences at edges. 

Receptive field

the specific area of the visual field where a stimulus will cause a neuron to respond. 

Center–surround receptive fields

(light) 

• Location: Retina & LGN

• Response: Light in center ↑ firing, light in surround ↓ firing

• Function: Detect contrast and edges

Edge receptive fields

(orientation)

• Location: V1 (primary visual cortex)

• Response: Lines or edges at specific orientations

• Function: Detect edges and shapes

Motion receptive fields

(motion)

• Location: Motion-sensitive areas (like MT)

• Response: Movement in a specific direction

• Function: Detect motion

Complex receptive fields

(complex shapes)

• Location: Higher visual areas

• Response: Specific shapes or objects

• Function: Recognize complex forms

Perceptual constancy

the ability to perceive objects as stable and unchanged even though the sensory input to the eyes changes. 

Size constancy 

• Objects are perceived as the same size even when they move closer or farther away 

• Example: a person doesn’t seem to shrink as they walk away 

Shape constancy 

• Objects are perceived as the same shape despite changes in viewing angle 

• Example: a door still looks rectangular when it is partly open 

Color (lightness) 

• Objects are perceived as having the same color under different lighting conditions 

• Example: a white shirt looks white in sunlight and indoors 

Unconscious inference

• the brain’s automatic, unconscious use of past experience and context to interpret sensory information. 

• ROLE: Without unconscious inference, the world would appear constantly changing and unstable. 

Binocular disparity

(both eyes)

Each eye sees a slightly different image → brain compares → bigger difference = closer

Convergence

Binocular perception

Eyes turn inward → more convergence = closer

Relative size

Monocular perception

Smaller = farther

Interposition/occlusion

Monocular perception

Object blocking another = closer

Linear perspective

Monocular perception

Parallel lines converge in distance

Texture gradient

Monocular perception

Textures denser = farther

Height in visual field

Monocular perception

Higher = farther

Motion parallax

Monocular perception

Nearby objects move faster across retina when you move

What is parallel processing in visual perception? 

Parallel processing is the simultaneous analysis of different visual features, such as color, motion, and form, by separate neural pathways. 

Describe the “what” and “where” pathways. Which is the dorsal stream, and which is the 

ventral stream? 

• The ventral “what” pathway identifies objects and goes to the inferotemporal cortex, while the dorsal “where” pathway identifies object location and motion and goes to the posterior parietal cortex. 

Define the difference between top-down and bottom-up processing. 

Bottom-up processing builds perception from sensory input, while top-down processing uses prior knowledge and expectations to interpret sensory input. 

Word frequency

Common words are recognized faster

• Example: “house” faster than “abacus”

Repetition priming

Seeing a word recently makes it easier to recognize

• Example: “drum” recognized faster after first exposure

Word superiority effect

Letters are recognized better in real words than alone

• Example: “E” in FARK vs. “E” alone

Well-formedness

Strings that follow normal spelling patterns are easier to read

• Example: “HIKE” easier than “HZYQ”

Bigrams (common letter pairs)

Strings with frequent letter pairs are easier to recognize

• Example: “HICE” easier than “HZEQ”

Describe the differences between feature search and conjunction search

Feature search is fast and based on a single distinguishing feature, while conjunction search is slower and requires attention to combine multiple features. 

Explain the design of a feature net, and how it would account for various phenomena 

(including errors) in word recognition. 

A feature net is a hierarchical network of detectors for features, letters, bigrams, and words, where activation spreads through the network to account for faster recognition of frequent or recently seen words, the word superiority effect, and common recognition errors. 

Fusiform Face Area (FFA)

• Brain region in the inferotemporal cortex (ventral stream)

• Specialized for face perception

• Highly active when seeing faces or distinguishing similar objects

Prosopagnosia

• Also called face blindness

• Can see faces but cannot recognize whose face it is

• Can be congenital or acquired

Holistic processing

Faces are recognized as a whole configuration, not just a collection of features

Inversion effect

Recognizing upside-down faces is much harder than upside-down objects 

Composite effect

Relationships between facial features help recognition 

Familiarity effect

We rely on internal features (eyes, nose, mouth) for familiar faces, external features (hair, head shape) for unfamiliar faces 

Expertise/generalization

FFA may also help distinguish objects in areas of expertise (like birds or cars for experts) 

Top-down influences on object recognition

Use prior knowledge, context, and expectations to interpret sensory input, especially when it’s incomplete or unclear.

examples of top down influences on object recognition

Examples:

1. Context: Fill in missing letters in a sentence → “b__k” = “bank”

2. Expectations: Recognize familiar objects in usual environments → cat in living room easier than cat in tree

3. Feature ambiguity: Correct unclear letters using knowledge → “Tpum” read as “TRUM”