Cognitive Neuroscience Exam 2 Review

Vocabulary flashcards covering methods, visual pathways, visual object recognition, and auditory processing for Cognitive Neuroscience Exam 2.

Cognitive neuroscience

The study of relationships between brain function and mental processes.

Converging operations

Using multiple research methods to investigate the same question, compensating for the limitations of individual methods.

Clinical participants

People with localized lesions, neurological or psychiatric syndromes, or relevant behavioral characteristics.

Neurologically intact participants

Individuals who provide a reference population for understanding typical brain function.

Computed Tomography (CT)

An imaging technique that produces X-ray-based images of internal structures to examine anatomy and structural abnormalities.

Magnetic Resonance Imaging (MRI)

A technique that generates detailed structural images using magnetic fields and radio waves.

Diffusion Tensor Imaging (DTI)

An imaging method that investigates white-matter organization and pathways by characterizing directional water diffusion.

Positron Emission Tomography (PET)

An imaging technique measuring signals from radioactive tracers to investigate metabolism and other biological processes.

Functional Magnetic Resonance Imaging (fMRI)

A technique measuring the BOLD signal (changes in blood oxygenation associated with neural activity), which reflects an indirect consequence of neural activity with slower temporal resolution than electrical methods.

Electroencephalography (EEG)

A method that measures electrical activity recorded from electrodes on the scalp.

Event-Related Potential (ERP)

A brain response associated with an event, extracted from EEG recordings.

Magnetoencephalography (MEG)

A method measuring magnetic fields produced by neural electrical activity.

Spatial resolution

How precisely a method identifies where neural activity occurs.

Temporal resolution

How precisely a method identifies when neural activity occurs.

Machine-learning model

A computational model that discovers patterns in data and can generalize to new situations.

Symbolic model

A computational model that represents complex symbol systems and relationships.

Neural-network model

A model composed of many simple units that send activation to other units.

Meta-analysis

A research method that combines results from multiple studies to assess consistency and overall evidence.

Retina

The light-sensitive tissue inside the eye that begins visual processing and sends information to the brain.

Phototransduction

The conversion of light energy into electrochemical signals by photoreceptors.

Rods

Highly sensitive photoreceptors concentrated primarily in the peripheral retina, best suited for detecting small amounts of light.

Cones

Photoreceptors concentrated most densely in the fovea, best suited for color vision and fine detail in brighter conditions.

Visual sensitivity

The ability to detect a stimulus, including weak light.

Visual acuity

The ability to distinguish fine visual details.

Rod convergence

The combining of signals from many rods, which reduces spatial precision by making it harder to pinpoint where light originated.

P ganglion cells

Retinal ganglion cells that encode color information and fine detail.

M ganglion cells

Retinal ganglion cells that process coarse patterns and rapid motion.

Receptive field

The region of sensory space to which a neuron responds.

Center-surround receptive fields

Receptive field organizations that help enhance contrast between neighboring regions, including edges.

Tectopulvinar pathway

A rapid visual route passing through the superior colliculus and pulvinar, involved in motion and novel peripheral stimuli.

Geniculostriate pathway

The major visual route from the retina through the optic nerve, optic chiasm, optic tract, LGN, and to V1.

Optic chiasm

The anatomical site where nasal retinal fibers cross while temporal retinal fibers remain on the same side.

Lateral geniculate nucleus (LGN)

A thalamic relay that organizes visual input before it reaches the primary visual cortex; M inputs project to magnocellular layers and P inputs project to parvocellular layers.

Retinotopic mapping

An organized mapping in the nervous system that preserves neighboring visual-field positions.

V1

Primary visual cortex (striate cortex); the cortical destination of the geniculostriate pathway.

Simple cell

A V1 cell that responds best to an edge of a particular orientation in a particular position.

Complex cell

A V1 cell selective for line orientation but less dependent on the exact position of the line.

End-stopped (hypercomplex) cell

A cortical cell that responds best to lines of particular orientations and lengths.

Cortical magnification factor

The amount of cortical surface devoted to a degree of visual angle, which is much greater for the fovea.

Orientation columns

Groups of cortical cells that share a preference for similar line orientations.

Ocular dominance columns

Groups of cortical cells organized by whether they primarily receive input from the left or right eye.

Hypercolumn

A group of cells representing a particular visual-field location with different orientation and eye-input preferences.

Binocular disparity

The difference between the images received by the two eyes, used to estimate depth.

Contextual modulation

The phenomenon where a neuron's response changes based on visual context outside its receptive field.

Cortical blindness

Blindness caused by damage to the visual cortex rather than the eye or optic nerve.

Blindsight

The ability of some patients with V1 damage to make visual discriminations without normal conscious visual experience.

V4

A visual area especially sensitive to color that also participates in processing orientation, depth, and motion.

Cerebral achromatopsia

Impaired color perception caused by brain damage, which can cause patients to see the world in shades of gray.

Ventral visual stream

The 'what' pathway extending toward the temporal lobe, supporting object identification.

Dorsal visual stream

The 'where/how' pathway extending toward the parietal lobe, supporting spatial processing and visually guided movement.

Visual agnosia

An inability to recognize objects through vision that is not explained by other causes, associated with ventral-stream damage.

Apperceptive agnosia

Difficulty forming a usable perceptual representation of an object.

Associative agnosia

A condition where a visual percept can be formed (such as copying a drawing) but cannot be linked to stored knowledge or meaning to identify or name it.

Category-specific agnosia

Difficulty recognizing or naming objects belonging to a particular category.

Prosopagnosia

Difficulty recognizing or distinguishing faces.

Developmental prosopagnosia

Face-recognition difficulty that arises developmentally rather than resulting from an acquired brain injury.

Thatcher illusion

An illusion demonstrating that face recognition depends strongly on configural information and is disrupted by inversion.

Configural processing

Processing the spatial relationships among parts of an object or face.

Sparse coding

A representational scheme where a relatively small, specific group of neurons responds to a given object or stimulus.

Grandmother cell theory

An extreme sparse-coding concept proposing that a single neuron responds to a specific person or object.

Population coding

A scheme in which an object is represented by the overall pattern of activity across a population of neurons.

Form-cue invariance

The stability of categorization regardless of the specific form of the cue used to represent an object.

Perceptual constancy

The ability to recognize an object across variations in angle, position, size, or illumination.

Lateral occipital complex (LOC)

A ventral-stream region involved in object shape recognition and recognition across changing cues, which responds more strongly to shapes than textures.

Local processing (Ventral stream)

Visual processing associated with the left ventral stream that is important for analyzing object parts.

Global processing (Ventral stream)

Visual processing associated with the right ventral stream that is important for analyzing whole forms.

Conjunctive coding

The combination of individual features through hierarchical processing into unified representations of shapes and objects.

Non-local binding

The representation of a whole object via the co-activation of units representing its parts in particular locations.

Fusiform face area (FFA)

A region in the fusiform gyrus strongly involved in face recognition, especially in the right hemisphere.

Visual word-form area (VWFA)

A left-hemisphere fusiform region associated with word perception.

Parahippocampal place area (PPA)

A ventral cortical region near the hippocampus that responds to scenes and buildings.

Extrastriate body area (EBA)

A cortical region that responds selectively to images of human bodies and body parts.

Double dissociation

A pattern where two abilities show opposite impairments, providing evidence for partly distinct neural systems.

Distributed processing model

A model stating that object categories are represented by patterns of activity distributed across the ventral stream.

Encoding (neuroimaging)

Predicting neural activity patterns from a presented stimulus.

Decoding (neuroimaging)

Predicting the stimulus identity from an observed pattern of neural activity.

Sound

Waves of compression and rarefaction in air produced by a vibrating object.

Sound amplitude

A physical dimension of sound waves that is perceptually related to loudness.

Sound frequency

A physical dimension of sound waves that is perceptually related to pitch.

Human hearing range

The perceptual range of acoustic frequencies spanning approximately $20\,\text{Hz}$ to $20,000\,\text{Hz}$.

Auditory transduction

The conversion of sound-related mechanical vibrations into neural signals.

Cochlea

An inner-ear organ containing hair cells that performs auditory transduction and frequency analysis.

Tonotopic mapping

The spatial arrangement where different sound frequencies are represented at different anatomical locations along the auditory system.

Inner hair cells

Sensory receptors that send auditory information toward the brain through afferent pathways.

Outer hair cells

Auditory receptor cells that modulate basilar membrane movement and receive efferent input.

Tip links

Filaments connecting adjacent stereocilia that help convert hair-bundle movement into receptor potentials.

Cochlear nucleus

An early auditory processing station situated in the medulla.

Superior olivary complex

The first site in the auditory pathway to receive input from both ears, assisting with sound localization.

Interaural time difference (ITD)

The difference in sound arrival time between the two ears, processed in the medial superior olive (MSO) via delay lines and coincidence detectors.

Interaural intensity difference (IID)

The difference in sound intensity reaching the two ears, processed by the lateral superior olive (LSO) and medial nucleus of the trapezoid body (MNTB).

Inferior colliculus

A midbrain structure containing an auditory space map organized by stimulus location.

Medial geniculate nucleus (MGN)

A thalamic auditory relay involved in processing combinations of sound frequencies and their timing.

Primary auditory cortex

Auditory cortical area located in the temporal lobe, just beneath the Sylvian fissure.

Auditory core region

A central auditory cortex area known for its tonotopic mapping and neurons tuned to particular frequency ranges.

Auditory belt areas

Auditory cortical areas that respond to complex sounds and show less tonotopic organization than the core region.

Auditory cortical streams

Dual processing pathways where posterior regions process spatial features and anterior regions process nonspatial sound features.

Auditory agnosia

An inability to recognize the meaning of sounds, categorized into verbal, nonverbal, and mixed types.